Arq (ARQ) 10-Q 9 May 23 2023 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2023	May 02, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
Document Transition Report	false
Entity File Number	001-37822
Entity Registrant Name	Advanced Emissions Solutions, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	27-5472457
Entity Address, Address Line One	8051 E. Maplewood Ave
Entity Address, Address Line Two	Suite 210
Entity Address, City or Town	Greenwood Village
Entity Address, State or Province	CO
Entity Address, Postal Zip Code	80111
City Area Code	720
Local Phone Number	598-3500
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Title of 12(b) Security	Common stock, par value $0.001 per share
Trading Symbol	ADES
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		27,228,984
Entity Central Index Key	0001515156
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
Entity Filer Category	Accelerated Filer

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash	$ 68,026	$ 66,432
Receivables, net	10,061	13,864
Inventories, net	20,232	17,828
Prepaid expenses and other current assets	6,405	7,538
Total current assets	104,724	105,662
Restricted cash, long-term	11,064	10,000
Property, plant and equipment, net of accumulated depreciation of $13,477 and $11,897, respectively	76,378	34,855
Other long-term assets, net	41,785	30,647
Total Assets	233,951	181,164
Current liabilities:
Accounts payable and accrued expenses	12,245	16,108
Current portion of debt obligations	1,611	1,131
Other current liabilities	6,188	6,645
Total current liabilities	20,044	23,884
Long-term debt obligations, net of current portion	20,119	3,450
Other long-term liabilities	13,647	13,851
Total Liabilities	53,810	41,185
Commitments and contingencies (Note 8)
Redeemable preferred stock - Series A Convertible Preferred subject to redemption: par value $0.001 per share, 8,900,000 shares authorized, 5,362,926 shares issued and outstanding	18,927	0
Stockholders’ equity:
Preferred stock: par value of $.001 per share, 50,000,000 shares authorized, none issued and outstanding except for Series A Convertible Preferred Stock	0	0
Common stock: par value of $.001 per share, 100,000,000 shares authorized, 31,854,636 and 23,788,319 shares issued, and 27,236,490 and 19,170,173 shares outstanding at March 31, 2023 and December 31, 2022, respectively	32	24
Treasury stock, at cost: 4,618,146 and 4,618,146 shares as of March 31, 2023 and December 31, 2022, respectively	(47,692)	(47,692)
Additional paid-in capital	132,590	103,698
Retained earnings	76,284	83,949
Total Stockholders’ Equity	161,214	139,979
Total Liabilities and Stockholders’ Equity	$ 233,951	$ 181,164

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Accumulated depreciation	$ 13,477	$ 11,897
Temporary equity, par value (in dollars per share)	$ 0.001	$ 0.001
Temporary equity, shares authorized (in shares)	8,900,000	8,900,000
Temporary equity, shares issued (in shares)	5,362,926	5,362,926
Temporary equity, shares outstanding (in shares)	5,362,926	5,362,926
Preferred stock par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	50,000,000	50,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	31,854,636	23,788,319
Common stock, shares outstanding (in shares)	27,236,490	19,170,173
Treasury stock (in shares)	4,618,146	4,618,146

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenues:
Total revenues	$ 20,805	$ 26,402
Operating expenses:
Consumables cost of revenue, exclusive of depreciation and amortization	17,175	21,507
Payroll and benefits	4,699	2,626
Legal and professional fees	4,538	2,172
General and administrative	2,778	1,926
Depreciation, amortization, depletion and accretion	2,137	1,506
Gain on sale of Marshall Mine, LLC	(2,695)	0
Total operating expenses	28,632	29,737
Operating loss	(7,827)	(3,335)
Other income (expense):
Earnings from equity method investments	638	833
Interest expense	(534)	(86)
Other	182	(445)
Total other income	286	302
Loss before income taxes	(7,541)	(3,033)
Income tax benefit	33	0
Net loss	$ (7,508)	$ (3,033)
Loss per common share (Note 1):
Basic (in dollars per share)	$ (0.32)	$ (0.17)
Diluted (in dollars per share)	$ (0.32)	$ (0.17)
Weighted-average number of common shares outstanding:
Basic (in shares)	23,770	18,344
Diluted (in shares)	23,770	18,344
Revenue from Contract with Customer, Product and Service [Extensible Enumeration]	Product [Member]	Product [Member]

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Retained Earnings
Beginning balance (in shares) at Dec. 31, 2021		23,460,212
Beginning balance (in shares) at Dec. 31, 2021			(4,618,146)
Beginning balance at Dec. 31, 2021	$ 147,301	$ 23	$ (47,692)	$ 102,106	$ 92,864
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (in shares)		323,742
Stock-based compensation	464	$ 1		463
Repurchase of common shares to satisfy minimum tax withholdings (in shares)		(59,736)
Repurchase of common shares to satisfy minimum tax withholdings	(382)			(382)
Net loss	(3,033)				(3,033)
Ending balance (in shares) at Mar. 31, 2022		23,724,218
Ending balance (in shares) at Mar. 31, 2022			(4,618,146)
Ending balance at Mar. 31, 2022	$ 144,350	$ 24	$ (47,692)	102,187	89,831
Beginning balance (in shares) at Dec. 31, 2022		23,788,319
Beginning balance (in shares) at Dec. 31, 2022	(4,618,146)		(4,618,146)
Beginning balance at Dec. 31, 2022	$ 139,979	$ 24	$ (47,692)	103,698	83,949
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (in shares)		483,242
Stock-based compensation	563			563
Issuance of common stock pursuant to Arq Acquisition, net of offering costs (in shares)		3,814,864
Issuance of common stock pursuant to Arq Acquisition, net of offering costs	12,437	$ 4		12,433
Issuance of common stock related to PIPE Investment, net of offering costs (in shares)		3,842,315
Issuance of common stock related to PIPE Investment, net of offering costs	15,220	$ 4		15,216
Issuance of warrants	826			826
Repurchase of common shares to satisfy minimum tax withholdings (in shares)		(74,104)
Repurchase of common shares to satisfy minimum tax withholdings	(146)			(146)
Preferred stock dividends declared on redeemable preferred stock	(157)				(157)
Net loss	$ (7,508)				(7,508)
Ending balance (in shares) at Mar. 31, 2023		31,854,636
Ending balance (in shares) at Mar. 31, 2023	(4,618,146)		(4,618,146)
Ending balance at Mar. 31, 2023	$ 161,214	$ 32	$ (47,692)	$ 132,590	$ 76,284

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities
Net loss	$ (7,508)	$ (3,033)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation, amortization, depletion and accretion	2,137	1,506
Gain on sale of Marshall Mine, LLC	(2,695)	0
Operating lease expense	738	663
Earnings from equity method investments	(638)	(833)
Stock-based compensation expense	563	464
Other non-cash items, net	11	550
Changes in operating assets and liabilities:
Receivables and related party receivables	3,867	2,095
Prepaid expenses and other assets	3,360	(725)
Inventories, net	(2,312)	(2,359)
Other long-term assets, net	(479)	3,116
Accounts payable and accrued expenses	(14,025)	(3,210)
Other current liabilities	(210)	(1,231)
Operating lease liabilities	(787)	2,680
Other long-term liabilities	273	910
Distributions from equity method investees, return on investment	0	1,501
Net cash (used in) provided by operating activities	(17,705)	2,094
Cash flows from investing activities
Acquisition of property, plant, equipment, and intangible assets, net	(3,545)	(1,359)
Cash and restricted cash acquired in business acquisition	2,225	0
Disposal of Marshall Mine, LLC	(2,177)	0
Distributions from equity method investees in excess of cumulative earnings	638	1,013
Mine development costs	(38)	(93)
Net cash used in investing activities	(2,897)	(439)
Cash flows from financing activities
Net proceeds from common stock issuance	15,220	0
Term Loan, related party, net of discount and issuance costs	8,522	0
Principal payments on finance lease obligations	(295)	(226)
Repurchase of common stock to satisfy tax withholdings	(146)	(382)
Principal payments on notes payable	(41)	0
Dividends paid on common stock	0	(20)
Net cash provided by (used) in financing activities	23,260	(628)
Increase in Cash and Restricted Cash	2,658	1,027
Cash and Restricted Cash, beginning of period	76,432	88,780
Cash and Restricted Cash, end of period	79,090	89,807
Supplemental disclosure of non-cash investing and financing activities:
Equity issued as consideration for acquisition of business	31,205	0
Change in accrued purchases for property and equipment	520	10
Paid-in-kind dividend on redeemable preferred stock	$ 157	$ 0

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation Nature of Operations Advanced Emissions Solutions, Inc. ("ADES" or the "Company") is a Delaware corporation with its principal office located in Greenwood Village, Colorado, manufacturing and logistics operations located in Louisiana and a manufacturing facility in Kentucky. The Company is an environmental technology company and has been principally engaged in the sale of consumable air and water treatment solutions including activated carbon ("AC") and chemical technologies. The Company's proprietary technologies in the advanced purification technologies ("APT") market enable customers to reduce air and water contaminants, including mercury and other pollutants, to maximize utilization levels and to improve operating efficiencies to meet the challenges of existing and pending air quality and water regulations. The Company manufactures and sells AC and other chemicals used to capture and remove contaminants for coal-fired power generation, industrial and water treatment markets. The Company also owns an associated lignite mine ("Five Forks Mine") that currently supplies the primary raw material for manufacturing AC. Acquisition On February 1, 2023 (the "Acquisition Date"), the Company entered into a Securities Purchase Agreement (the "Purchase Agreement") with Arq Limited ("Arq Ltd."), a company incorporated under the laws of Jersey, pursuant to which the Company acquired all of the direct and indirect equity interests of Arq Ltd.'s subsidiaries (the "Arq Acquisition," and hereafter referred to as "Arq") in exchange for consideration (the "Purchase Consideration") totaling $31.2 million, and consisting of (i) 3,814,864 shares of the Company's common stock, par value $0.001 per share (the "Common Stock") and (ii) 5,294,462 shares (the "Preferred Shares") of the Company's Series A Convertible Preferred Stock, par value $0.001 per share (the "Series A Preferred Stock"). Arq's principal office is located in London, United Kingdom with an additional office located in Corbin, Kentucky near its production facility ("the Corbin Facility"). The Corbin location consists of bituminous coal reserves and a manufacturing facility to recover and purify the bituminous coal fines for sale or further conversion to value-added specialty chemicals. Arq is a pre-revenue, environmental technology company that has developed a process for transforming coal waste into a purified, microfine carbon powder, known as Arq powder TM ("Arq Powder"). The Company expects to begin using Arq Powder to produce granular activated carbon ("GAC") products in the second half of 2024. See further discussion of the Arq Acquisition in Note 2. Loan Agreement As required under the Purchase Agreement, and on February 1, 2023 (the "Closing Date"), the Company, as borrower, certain of its subsidiaries, as guarantors, and CF Global ("CFG"), a related party, as administrative agent and lender (the "Lender"), entered into a term loan (the "Term Loan") in the amount of $10.0 million, less original issue discount ("OID") of $0.2 million, upon execution of a Term Loan and Security Agreement (the "Loan Agreement"). The Company received net cash proceeds of $8.5 million after deducting the OID and debt issuance costs of $1.3 million. The Loan Agreement also provides for the issuance of a warrant (the "Warrant") to CFG to purchase 325,457 shares of Common Stock (the "Warrant Shares"), which represents 1% of the post-Arq Acquisition and PIPE Investment (as defined below) fully diluted share capital (as defined in the Loan Agreement), at an exercise price of $0.01 per share. The Warrant has a term of 7 years and contains a cashless exercise provision. See further discussion of the Term Loan in Note 6. Equity Financing On February 1, 2023, the Company entered into Subscription Agreements (the "Subscription Agreements") with certain persons (the "Subscribers"), which included existing shareholders of Arq Ltd., three of which were appointed to the Company's Board of Directors (the "Board"), pursuant to which the Subscribers subscribed for and purchased shares of Common Stock for an aggregate purchase price of $15.4 million and at a price per share of $4.00 (such transaction, the "PIPE Investment"). See further discussion of the PIPE Investment in Note 11. Basis of Presentation The accompanying Condensed Consolidated Financial Statements of ADES are unaudited and have been prepared in conformity with accounting principles generally accepted in the United States ("U.S. GAAP") and with Article 10 of Regulation S-X of the Securities and Exchange Commission. In compliance with those instructions, certain information and footnote disclosures normally included in annual consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. The unaudited Condensed Consolidated Financial Statements of ADES in this quarterly report ("Quarterly Report") are presented on a consolidated basis and include ADES and its wholly-owned subsidiaries (collectively, the "Company"). Also included within the unaudited Condensed Consolidated Financial Statements are the Company's unconsolidated equity investments, Tinuum Group and Tinuum Services, which are accounted for under the equity method of accounting, and Highview Enterprises Limited (the "Highview Investment"), which is accounted for in accordance with U.S. GAAP applicable to equity investments that do not qualify for the equity method of accounting. Results of operations and cash flows for the interim periods are not necessarily indicative of the results that may be expected for the entire year. All significant intercompany transactions and accounts were eliminated in consolidation for all periods presented in this Quarterly Report. In the opinion of management, these Condensed Consolidated Financial Statements include all normal and recurring adjustments considered necessary for a fair presentation of the results of operations, financial position, stockholders' equity and cash flows for the interim periods presented. These Condensed Consolidated Financial Statements should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2022 (the "2022 Form 10-K"). Significant accounting policies disclosed therein have not changed. Earnings (Loss) Per Share Basic earnings (loss) per share is computed using the weighted-average number of shares of common stock outstanding during the reporting period. Diluted earnings (loss) per share is computed in a manner consistent with that of basic earnings per share, while considering other potentially dilutive securities. For the three months ended March 31, 2023 and 2022, potentially dilutive securities consist of unvested restricted stock awards ("RSAs") and contingent performance stock units ("PSUs"). For the three months ended March 31, 2023 potentially dilutive securities also consist of outstanding shares of Series A Preferred Stock, which contain non-forfeitable rights to earnings and dividends in the form of cash or shares of Series A Preferred Stock (the "Preferred Dividends"), determined at the option of the Company, and are deemed to be participating securities ("Participating Securities"). As permitted, the Company has elected not to separately present basic or diluted earnings (loss) per share attributable to Participating Securities in the Consolidated Statement of Operations for the three months ended March 31, 2023. The following table sets forth the calculations of basic and diluted loss per share: Three Months Ended March 31, (in thousands, except per share amounts) 2023 2022 Net loss $ (7,508) $ (3,033) Less: Dividends declared on redeemable preferred stock 157 — Loss attributable to common stockholders $ (7,665) $ (3,033) Basic weighted-average common shares outstanding 23,770 18,344 Add: dilutive effect of equity instruments — — Diluted weighted-average shares outstanding 23,770 18,344 Loss per share - basic $ (0.32) $ (0.17) Loss per share - diluted $ (0.32) $ (0.17) For the three months ended March 31, 2023 and 2022, potentially dilutive securities of 4.2 million and 0.3 million shares of common stock, respectively, were outstanding but were not included in the calculation of diluted net loss per share because the effect would have been anti-dilutive. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. There have been no changes in the Company’s critical accounting estimates from those that were disclosed in the 2022 Form 10-K. Actual results could differ from these estimates. Risks and Uncertainties For 2023, the Company is principally dependent on the operations of its APT business and its cash on hand to provide liquidity over the near and long term. The Company's revenues, sales volumes, earnings and cash flows are significantly affected by prices of competing power generation sources such as natural gas and renewable energy. During periods of low natural gas prices, natural gas provides a competitive alternative to coal-fired power generation and therefore, coal consumption for purposes of power generation may be reduced, which in turn reduces the demand for the Company's products. However, during periods of higher prices for competing power generation sources, there is an increase in coal consumption and thus demand for the Company's products also increases. In addition, coal consumption for purposes of power generation and demand for the Company's products are affected by the demand for electricity, which is higher in the warmer and colder months of the year. As a result, the Company's interim period results are subject to seasonal variations whereby its revenues and cost of revenues tend to be higher in its first and third fiscal quarters compared to its second and fourth fiscal quarters. Abnormal temperatures during the summer and winter months may significantly affect coal consumption and impurities within various municipalities' water sources, and thus impact the demand for the Company's products. Concentration of credit risk The Company is exposed to concentrations of credit risk primarily related to cash held at financial institutions and accounts receivable. The Company regularly monitors its credit risk to mitigate the possibility of current and future exposures resulting in a loss. Historically, the losses related to credit risk have been immaterial. The Company evaluates the creditworthiness of its customers prior to entering into agreements to sell its products and, as necessary, throughout the life of the customer relationship. The Company holds substantially all of its cash at one financial institution as of March 31, 2023. If a financial institution was unable to perform its obligations, the Company would be at risk regarding the amount of cash and investments in excess of the Federal Deposit Insurance Corporation limits (currently $250 thousand) that would be returned to the Company. Reclassifications Certain balances have been reclassified from the prior year to conform to the current year presentation. Such reclassifications had no effect on the Company’s results of operations or financial position in any of the periods presented. New Accounting Standards Effective January 1, 2023, the Company adopted ASU 2016-13, Financial Instruments - Credit Losses (Topic 326) Measurement of Credit Losses on Financial Instruments ("ASU 2016-13"). The main objective of ASU 2016-13 is to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. The adoption of ASU 2016-13 did not have a material impact on the Company's financial statements and disclosures.

Arq Acquisition

Arq Acquisition	3 Months Ended
	Mar. 31, 2023
Business Combination and Asset Acquisition [Abstract]
Arq Acquisition	Arq AcquisitionThe Company accounted for the Arq Acquisition as an acquisition of a business as of the Acquisition Date. The total Purchase Consideration was $31.2 million and has been preliminarily allocated to the acquired assets and assumed liabilities of Arq based on their estimated fair values as of the Acquisition Date. The Purchase Consideration was comprised of the fair values as of the Acquisition Date of 3,814,864 shares of Common Stock, valued at $12.4 million, and 5,294,462 Preferred Shares, valued at $18.8 million. The Company also incurred $8.7 million in acquisition-related costs, which were expensed as incurred and included in the "General and administrative" line item in the Statements of Operations. The following table provides the preliminary estimated fair values of the assets acquired and liabilities assumed as of the Acquisition Date: (in thousands) Purchase Price Allocation Fair value of assets acquired: Cash $ 1,411 Prepaid expenses and other current assets 2,229 Restricted cash, long-term 814 Property, plant and equipment, net 39,159 Other long-term assets, net 11,717 Amount attributable to assets acquired 55,330 Fair Value of liabilities assumed: Accounts payable and accrued expenses 9,806 Current portion of long-term debt 494 Other current liabilities 103 Long-term debt, net of current portion 9,199 Other long-term liabilities 4,523 Amount attributable to liabilities assumed 24,125 Net assets acquired $ 31,205 The following represents the intangible asset identified as part of the Arq Acquisition and which is included in "Other long-term-assets, net" in the table above: (in thousands) Amount Weighted Average Useful Life (years) Developed technology $ 7,700 20 Redeemable Preferred Stock In connection with the issuance of the Series A Preferred Stock pursuant to the Purchase Agreement, the Company filed the Certificate of Designations of Preferred Stock for the Series A Preferred Stock (the "Certificate of Designations") with the Secretary of State of the State of Delaware. Under the Certificate of Designations, 8.9 million preferred shares were designated as Series A Preferred Stock. Each outstanding share of Series A Preferred Stock will be automatically converted into the number of shares of Common Stock described below upon approval by the stockholders of the Company. Each share of Series A Preferred Stock is deemed to have an original issue price of $4.00 per share (the "Original Issue Amount"). The number of shares of Common Stock issued upon conversion of each share of Series A Preferred Stock shall be equal to the product of (i) the sum of (A) the Original Issue Amount plus (B) an amount equal to the cumulative amount of the accrued and unpaid dividends on such share at such time divided by (ii) the Original Issue Amount, subject to adjustment. Holders of the Series A Preferred Stock are entitled to receive cumulative dividends, which accrue quarterly on the last day of each applicable quarter (whether or not declared or funds for their payment are lawfully available) and are payable quarterly, in arrears, on the earlier to occur of (a) the date any dividend is paid to holders of Common Stock with respect to such quarter and (b) 30 days after the end of each quarter (the "Series A Quarterly Dividend") at the rate per share of Series A Preferred Stock equal to the greater of (i) if the Company declares a cash dividend on the Common Stock with respect to such quarter, the amount of the cash dividend that would be received by a holder of Common Stock in which such share of Series A Preferred Stock would be convertible on the record date for such cash dividend and (ii) an annual rate (the "Rate") of 8.0% of the Original Issue Amount compounded quarterly with respect to such quarter. The Rate will increase by 2.0% on the first day of the first quarter ending on or after the 635th day following the closing date of the first issuance of Series A Preferred Stock and on each subsequent anniversary of such date. The Series A Quarterly Dividend is payable in cash or in additional shares of Series A Preferred Stock (the "Series A PIK Shares"), at the option of the Company. The number of Series A PIK Shares to be issued is determined by dividing (i) the Series A Quarterly Dividend payable with respect to all shares of Series A Preferred Stock held by a holder thereof by (ii) the aggregate Original Issue Amount of all shares of Series A Preferred Stock held by a holder thereof, and each fractional Series A PIK Share is rounded to the nearest whole Series A PIK Share (with 0.5 of a share being rounded down to 0.0). On March 31, 2023, the Company declared a dividend of 68,464 Series A PIK Shares with respect to the accrued dividends on the Series A Preferred Stock for the first quarter of 2023 (the "First Quarter PIK Dividend"). The First Quarter PIK Dividend was recorded at the estimated fair value of $0.2 million as of March 31, 2023 and was paid on April 21, 2023. In the event of the Company's liquidation, dissolution or winding up, after payment or provision for payment of its debt and other liabilities, a holder of Series A Preferred Stock will receive a liquidating distribution equal to the amount of the cumulative accrued but unpaid dividends on each share of Series A Preferred Stock held by such holder. After the payment to the holders of Series A Preferred Stock of such liquidation preference, the holders of outstanding shares of Series A Preferred Stock will participate pari passu with the holders of Common Stock on an as-converted basis in any remaining distributions out of the Company’s assets available for distribution to stockholders. Holders of shares of Series A Preferred Stock generally have no voting rights. However, the Company is restricted from taking certain actions without the written consent or affirmative vote of the holders of at least a majority of the then outstanding shares of Series A Preferred Stock, including, but not limited to, amending the Company's Certificate of Incorporation or Bylaws in a manner that adversely affects the rights of the Series A Preferred Stock or consummating a merger of the Company with or into another party or a sale of substantially of its assets. If the approval by the stockholders of the Company of conversion of the Series A Preferred Stock has not been obtained, each outstanding share of Series A Preferred Stock will be redeemed by the Company on February 1, 2028 for cash, at a redemption price equal to the sum of (i) the product of (x) 140% and (y) the Original Issue Amount, plus (ii) an amount equal to the cumulative amount of accrued and unpaid dividends on such share of Series A Preferred Stock. Under the terms of the Purchase Agreement, a total of 833,914 Preferred Shares, are being held in escrow (the "Escrow Shares") based on a contingent redemption feature, (the "Contingent Redemption Feature," as defined below). The fair value of the Preferred Shares issued was determined to be $3.46 per Preferred Share on the Acquisition Date (the "Preferred Share Price") plus the value of the Contingent Redemption Feature related to the Escrow Shares. The Escrow Shares are being withheld pending a determination by the IRS that no tax withholding is required on the Purchase Consideration issued to Arq Ltd. (the "Arq Ltd. Tax Liability"). The Company estimated the fair value of the potential Arq Ltd. Tax Liability at $3.3 million. In the event that the IRS determines that no withholding is required by Arq Ltd. in connection with the Purchase Consideration received by Arq Ltd., all of the Escrow Shares will be released and delivered to Arq Ltd. In the event that the IRS determines that any amount of withholding is required by Arq Ltd., the Company has agreed to redeem a sufficient number of Escrow Shares to fund the required payment to the IRS, and that number of Escrow Shares will be returned to the Company (the "Contingent Redemption Feature"). The number of Escrow Shares to be returned to the Company is equal to the required withholding amount divided by the Original Issue Amount, not to exceed a maximum of 833,914 Escrow Shares, and is equal to $3.3 million based on the Original Issue Amount (the "Maximum Contingent Redemption Amount"). The fair value of the Escrow Shares is the Maximum Contingent Redemption Amount and the fair value of the non-escrowed Preferred Shares ("Non Escrow Shares") is the Preferred Share Price. The Series A Preferred Stock contains a mandatory redemption feature in the event the Preferred Shares, including future Preferred Shares issued under dividend requirements, are not converted into shares of Common Stock prior to February 1, 2028. The Company has determined that both the Escrow Shares and the Non Escrow Shares do not meet the definition of mandatorily redeemable financial instruments as there is a substantive conversion feature, and are therefore not classified as liabilities. As both the Escrow Shares and Non Escrow Shares represent financial instruments that are redeemable for cash, SEC guidance mandates that preferred securities which are redeemable upon the occurrence of an event that is not solely within the control of the issuer be classified outside of permanent equity as "temporary equity." Accordingly, the Company has classified all of the Preferred Shares as temporary equity and reported them as "Redeemable preferred stock" in the Consolidated Balance Sheet as of as of March 31, 2023. Other The amounts of revenues and net loss for Arq for the period from the Acquisition Date to March 31, 2023 are as follows: Three Months Ended March 31, (in thousands) 2023 Revenues $ — Net loss $ (3,650) The following represents the pro forma effects of the Arq Acquisition as if it had occurred on January 1, 2022. The pro forma net loss for each of the two years presented has been calculated after applying the Company’s accounting policies in effect for those years. In addition, pro forma net loss includes: (1) for the three months ended March 31, 2022, an increase in Payroll and benefits for compensation expense of $1.9 million payable to certain Arq employees, triggered by change in control provisions in employment agreements, as well as in employee severance agreements that has not been recognized in the historical financial statements, assuming such amounts will be paid in cash; (2) for each of the three months ended March 31, 2023 and 2022, a decrease in depreciation and amortization of $0.2 million and $0.6 million, respectively, resulting from fair value adjustments to Property, plant, equipment; (3) for each of the three months ended March 31, 2023 and 2022, an increase in amortization of $0.1 million and $0.1 million, respectively, resulting from fair value adjustments to intangible assets; (4) for each of the three months ended March 31, 2023 and 2022, increases to Interest expense of $0.2 million and $0.3 million, respectively for: (a) the issuance of the Term Loan (as defined below) including stated interest and the amortization of the Term Loan's discount and issuance costs and (b) amortization of debt discount related to a fair value adjustment to an assumed term loan of Arq; and (5) the removal of $6.6 million of transaction costs incurred for the period from April 1, 2022 to March 31, 2023 but included as additional transaction costs for the three months ended March 31, 2022, together with the income tax effects on (1) through (5). Since Arq had no revenues for the three months ended March 31, 2023 or 2022, pro forma revenues are the same as the Company's reported revenues for those periods. Three Months Ended March 31, (in thousands) 2023 2022 Revenues $ 20,805 $ 26,402 Net loss $ (4,069) $ (13,009)

Marshall Mine

Marshall Mine	3 Months Ended
	Mar. 31, 2023
Business Combination and Asset Acquisition [Abstract]
Marshall Mine	Marshall Mine On September 2, 2022, (the "MM Purchase Date"), a subsidiary of Advanced Emissions Solutions, Inc., ADA Carbon Solutions (Operations), LLC (the "Seller"), entered into a Membership Interest Purchase Agreement (the "MM Purchase Agreement") with Caddo Creek Resources Company, L.L.C. (the "Buyer") to sell all of its membership interests in Marshall Mine, LLC to the Buyer (the "MM Transaction") in exchange for a cash payment to be made by the Seller to the Buyer and the assumption by the Buyer of certain liabilities of Marshall Mine, LLC. The Buyer previously operated the Marshall Mine on behalf of Marshall Mine, LLC and was performing final mine reclamation under a fixed price contract. The obligations of the Seller and the Buyer to close the Transaction were subject to certain customary closing conditions (the "Conditions") as set forth in the Purchase Agreement, including, but not limited to, (1) obtaining the approval of the Railroad Commission of Texas (the "Commission") for a change in control of Marshall Mine from Seller to Buyer or an affiliate of the Buyer; and (2) the Buyer replacing the Seller’s surety bond with a reclamation performance bond, letter of credit or other form of security to which the Buyer or an affiliate of the Buyer is the principal that is satisfactory to the Commission. On March 27, 2023, (the "MM Closing Date") all of the Conditions for closing the MM Transaction were satisfied, and the Company made a cash payment to the Buyer in the amount of $2.2 million (the "MM Purchase Price"). As of the MM Closing Date, Marshall Mine, LLC had outstanding liabilities of approximately $4.9 million that were discharged upon payment of the MM Purchase Price by the Company, and the Company recognized a gain of approximately $2.7 million in the Statement of Operations for the three months ended March 31, 2023. Subsequent to March 31, 2023, the Company was permitted to reduce its restricted cash requirement by $2.3 million to $7.7 million.

Revenues

Revenues	3 Months Ended
	Mar. 31, 2023
Revenue from Contract with Customer [Abstract]
Revenues	Revenues Trade receivables represent an unconditional right to consideration in exchange for goods or services transferred to a customer. The Company invoices its customers in accordance with the terms of the contract. Credit terms are generally net 30 - 45 days from the date of invoice. The timing between the satisfaction of performance obligations and when payment is due from the customer is generally not significant. Contract liabilities are comprised of deferred revenue, which represents an obligation to transfer goods or services to a customer for which the Company has received consideration from the customer and, if deliverable within one year or less, is included in "Other current liabilities" in the Condensed Consolidated Balance Sheets and, if deliverable outside of one year, is included in "Other long-term liabilities" in the Condensed Consolidated Balance Sheets. The following table shows the components of the Company's Receivables, net: As of (in thousands) March 31, 2023 December 31, 2022 Trade receivables, net $ 9,989 $ 13,789 Other receivables 72 75 Receivables, net $ 10,061 $ 13,864

Inventories, net

Inventories, net	3 Months Ended
	Mar. 31, 2023
Inventory Disclosure [Abstract]
Inventories, net	Inventories, net The following table summarizes the Company's inventories recorded at the lower of average cost or net realizable value, as of March 31, 2023 and December 31, 2022: As of (in thousands) March 31, 2023 December 31, 2022 Product inventory, net $ 10,356 $ 9,479 Raw material inventory 9,876 8,349 Total inventories, net $ 20,232 $ 17,828

Debt Obligations

Debt Obligations	3 Months Ended
	Mar. 31, 2023
Debt Disclosure [Abstract]
Debt Obligations	Debt Obligations As of (in thousands) March 31, 2023 December 31, 2022 Term Loan due February 2027, related party $ 10,000 $ — Arq Loan due January 2036 9,960 — Finance lease obligations 4,287 4,581 24,247 4,581 Unamortized debt discounts (1,288) — Unamortized debt issuance costs (1,229) — 21,730 4,581 Less: Current maturities (1,611) (1,131) Total long-term debt obligations $ 20,119 $ 3,450 Term Loan The Term Loan has a term of 48 months and bears interest at a rate equal to either (a) Adjusted Term SOFR (subject to a 1.00% floor and a cap of 2.00%) plus a margin of 9.00% paid in cash and 5.00% paid in kind or (b) Base Rate plus a margin of 8.00% paid in cash and 5.00% paid in kind, which interest on the Term Loan in each case shall be payable (or capitalized, in the case of in kind interest) quarterly in arrears. The Company may prepay the Term Loan at any time subject to the following prepayment premium: (i) prior to the twelve month anniversary of the Closing Date, the Make-Whole Amount (as defined below), (ii) thereafter but prior to the thirty-six month anniversary of the Closing Date, 2.00% of the outstanding principal amount of the Term Loan being repaid or prepaid or (iii) thereafter until the maturity date, 1.00% of the outstanding principal amount of the Term Loan being repaid or prepaid. The "Make-Whole Amount," with respect to any repayment or prepayment, is (i) an amount equal to all required interest payable (except for currently accrued and unpaid interest) on the aggregate principal amount of the Term Loan subject to such prepayment or repayment from the date of such prepayment or repayment through but excluding the date that is the first anniversary of the Closing Date calculated using an interest rate equal to (x) Adjusted Term SOFR for an interest period of one month in effect on the third U.S. Government Securities Business Day prior to such prepayment or repayment plus (y) 14.00% per annum and assuming all interest was paid in cash, plus (ii) a prepayment premium of 2.00% on the aggregate principal amount of the Term Loan subject to such prepayment or repayment. The Term Loan is secured by substantially all of the assets of the Company and its subsidiaries (including those acquired in the Acquisition, but excluding those pledged as collateral under the Arq Loan, as defined and described below), subject to customary exceptions. The Loan Agreement includes, among others, the following covenants: (1) beginning with the first fiscal quarter after March 31, 2023 and as of the end of each fiscal quarter thereafter, the Company must maintain a minimum unrestricted cash balance of $5.0 million; (2) (x) as of December 31, 2023, for the fiscal year then ended, the Company must have a minimum annual revenue, on a consolidated basis, of $70.0 million, (y) as of December 31, 2024, for the fiscal year then ended, the Company must have a minimum annual revenue, on a consolidated basis, of $85.0 million and (z) for any fiscal year thereafter, the Company must have a minimum annual revenue, on a consolidated basis, of $100.0 million; (3) (x) as of December 31, 2024, for the fiscal year then ended, the Company must have a minimum Consolidated EBITDA of $3.0 million and (y) for any fiscal year thereafter, the Company must have a minimum Consolidated EBITDA of $16.0 million; and (4) beginning after the fiscal quarter ending September 30, 2023, during an LTV Trigger Period, ADES must not exceed a loan to value (based on the consolidated total assets of the Company and its subsidiaries) ratio of 0.40:1.00. The Company allocated the cash proceeds of the Term Loan to both the Term Loan and the Warrant based on their relative fair values. The amount allocated to the Warrant was recorded as a debt discount and is amortized to interest expense over the term of the Term Loan. The standalone fair value of the Term Loan was based on a comparison of borrowings and associated credit ratings consistent with those of the Company. As the Warrant is exercisable for $0.01 per share, the fair value is deemed to be equal to the fair value of the underlying shares, and accordingly, the fair value of the Warrant was determined as the number of shares issuable from the exercise of the Warrant (based on 1.0% of post-transaction fully diluted share capital, as defined in the Purchase Agreement) multiplied by the closing share price of the Company's common stock on the Acquisition Date. Arq Loan As consideration in the Arq Acquisition, the Company assumed a term loan (the "Arq Loan") held by certain Arq subsidiaries as set out in the Arq Loan (the "Arq Borrowers") with a financial institution in the principal amount of $10.0 million. The Company recorded the Arq Loan on the Acquisition Date at its estimated fair value of $9.7 million, with the difference between the estimated fair value and the principal amount of $0.3 million recorded as a debt discount. This debt discount is recognized as interest expense over the term of the Arq Loan. The Arq Loan was executed on January 27, 2021 and is comprised of two promissory notes (the "Notes"): (1) "Note A" in the principal amount of $8.0 million, which is guaranteed by the U.S. Department of Agriculture; and (2) "Note B" in the principal of $2.0 million. The Notes expire on January 27, 2036 and bear interest at 6.0% per annum through January 2026 and at prime plus 2.75% thereafter. Beginning January 27, 2023 and for the balance of the term of the Arq Loan, the Arq Borrowers are required to make combined interest and principal payments monthly in the fixed amount of $0.1 million. Interest is computed and payable on the outstanding principal as of the end of the prior month and the balance of the fixed monthly payment amount is applied to the outstanding principal. The Notes carry a prepayment penalty of 3.0% of the outstanding principal if paid prior to January 27, 2024, 2.0% of the outstanding principal if paid prior to January 27, 2025 and 1.0% of the outstanding principal if paid prior to January 27, 2026. Thereafter, the Arq Loan may be prepaid without penalty.

Leases

Leases	3 Months Ended
	Mar. 31, 2023
Leases [Abstract]
Leases	Leases The Company's operating and finance lease right-of-use ("ROU") assets and liabilities as of March 31, 2023 and December 31, 2022 consisted of the following items (in thousands): As of Leases March 31, 2023 December 31, 2022 Operating Leases Operating lease right-of-use assets, net of accumulated amortization (1) $ 10,122 $ 7,734 Operating lease obligations, current $ 2,554 $ 2,724 Long-term operating lease obligations 7,642 5,133 Total operating lease obligation $ 10,196 $ 7,857 Finance Leases Finance lease right-of-use assets, net of accumulated amortization (2) $ 2,343 $ 2,565 Finance lease obligations, current $ 1,117 $ 1,131 Long-term finance lease obligations 3,170 3,450 Total finance lease obligations $ 4,287 $ 4,581 (1) Operating lease ROU assets are reported net of accumulated amortization of $5.1 million and $4.4 million as of March 31, 2023 and December 31, 2022, respectively. (2) Finance lease ROU assets are reported net of accumulated amortization of $2.2 million and $2.0 million as of March 31, 2023 and December 31, 2022, respectively. Operating leases ROU assets under operating leases and operating lease liabilities are included in the " Other long-term assets Other current liabilities Other long-term liabilities Lease expense for operating leases for the three months ended March 31, 2023 was $1.4 million, of which $1.1 million is included in the "Consumables - cost of revenue, exclusive of depreciation and amortization" line item, and $0.3 million is included in the "General and administrative" line item in the Condensed Consolidated Statements of Operations for those periods. Lease expense for operating leases for the three months ended March 31, 2022 was $1.1 million, of which $1.0 million, is included in the "Consumables - cost of revenue, exclusive of depreciation and amortization" line item, and $0.1 million, is included in "General and administrative" line item in the Condensed Consolidated Statements of Operations for those periods. Finance leases ROU assets under finance leases are included in the "Property, plant and equipment" line item in the Condensed Consolidated Balance Sheets as of March 31, 2023 and December 31, 2022. Interest expense related to finance lease obligations and amortization of ROU assets under finance leases are included in the "Interest expense" and "Depreciation, amortization, depletion and accretion" line items, respectively, in the Condensed Consolidated Statements of Operations for the three months ended March 31, 2023 and 2022. Lease financial information as of and for the three months ended March 31, 2023 and 2022 is provided in the following table: Three Months Ended March 31, (in thousands) 2023 2022 Finance lease cost: Amortization of right-of-use assets $ 223 $ 141 Interest on lease liabilities 307 78 Operating lease cost 982 806 Short-term lease cost 409 243 Variable lease cost (1) 8 9 Total lease cost $ 1,929 $ 1,277 Other Information: Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for finance leases $ 307 $ 78 Operating cash flows for operating leases $ 787 $ 738 Financing cash flows for finance leases $ 295 $ 226 Right-of-use assets obtained in exchange for new finance lease liabilities $ — $ — Right-of-use assets obtained in exchange for new operating lease liabilities $ — $ 3,418 Weighted-average remaining lease term - finance leases 2.5 years 2.7 years Weighted-average remaining lease term - operating leases 7.7 years 4.4 years Weighted-average discount rate - finance leases 5.9 % 6.3 % Weighted-average discount rate - operating leases 9.8 % 6.0 % (1) Primarily includes common area maintenance, property taxes and insurance payable to lessors.
Leases	Leases The Company's operating and finance lease right-of-use ("ROU") assets and liabilities as of March 31, 2023 and December 31, 2022 consisted of the following items (in thousands): As of Leases March 31, 2023 December 31, 2022 Operating Leases Operating lease right-of-use assets, net of accumulated amortization (1) $ 10,122 $ 7,734 Operating lease obligations, current $ 2,554 $ 2,724 Long-term operating lease obligations 7,642 5,133 Total operating lease obligation $ 10,196 $ 7,857 Finance Leases Finance lease right-of-use assets, net of accumulated amortization (2) $ 2,343 $ 2,565 Finance lease obligations, current $ 1,117 $ 1,131 Long-term finance lease obligations 3,170 3,450 Total finance lease obligations $ 4,287 $ 4,581 (1) Operating lease ROU assets are reported net of accumulated amortization of $5.1 million and $4.4 million as of March 31, 2023 and December 31, 2022, respectively. (2) Finance lease ROU assets are reported net of accumulated amortization of $2.2 million and $2.0 million as of March 31, 2023 and December 31, 2022, respectively. Operating leases ROU assets under operating leases and operating lease liabilities are included in the " Other long-term assets Other current liabilities Other long-term liabilities Lease expense for operating leases for the three months ended March 31, 2023 was $1.4 million, of which $1.1 million is included in the "Consumables - cost of revenue, exclusive of depreciation and amortization" line item, and $0.3 million is included in the "General and administrative" line item in the Condensed Consolidated Statements of Operations for those periods. Lease expense for operating leases for the three months ended March 31, 2022 was $1.1 million, of which $1.0 million, is included in the "Consumables - cost of revenue, exclusive of depreciation and amortization" line item, and $0.1 million, is included in "General and administrative" line item in the Condensed Consolidated Statements of Operations for those periods. Finance leases ROU assets under finance leases are included in the "Property, plant and equipment" line item in the Condensed Consolidated Balance Sheets as of March 31, 2023 and December 31, 2022. Interest expense related to finance lease obligations and amortization of ROU assets under finance leases are included in the "Interest expense" and "Depreciation, amortization, depletion and accretion" line items, respectively, in the Condensed Consolidated Statements of Operations for the three months ended March 31, 2023 and 2022. Lease financial information as of and for the three months ended March 31, 2023 and 2022 is provided in the following table: Three Months Ended March 31, (in thousands) 2023 2022 Finance lease cost: Amortization of right-of-use assets $ 223 $ 141 Interest on lease liabilities 307 78 Operating lease cost 982 806 Short-term lease cost 409 243 Variable lease cost (1) 8 9 Total lease cost $ 1,929 $ 1,277 Other Information: Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for finance leases $ 307 $ 78 Operating cash flows for operating leases $ 787 $ 738 Financing cash flows for finance leases $ 295 $ 226 Right-of-use assets obtained in exchange for new finance lease liabilities $ — $ — Right-of-use assets obtained in exchange for new operating lease liabilities $ — $ 3,418 Weighted-average remaining lease term - finance leases 2.5 years 2.7 years Weighted-average remaining lease term - operating leases 7.7 years 4.4 years Weighted-average discount rate - finance leases 5.9 % 6.3 % Weighted-average discount rate - operating leases 9.8 % 6.0 % (1) Primarily includes common area maintenance, property taxes and insurance payable to lessors.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Retention Agreements As of December 31, 2022, the Company had an outstanding liability of $1.4 million (the "Retention Liability"), which was included in the "Other current liabilities" line item in the Condensed Consolidated Balance Sheet, related to retention agreements (the "Retention Agreements") executed between the Company and its executive officers and certain other key employees in May 2021 and amended in May 2022 in order to maintain the Company's business operations while it pursued and executed on its strategic initiatives. The Retention Agreements were approved by the Compensation Committee of the Board of Directors and the Board of Directors (the "Board") in May 2021 and May 2022. In August 2022, the Company paid $1.0 million pursuant to the payment terms of the Retention Agreements and the Retention Liability was paid in full in January 2023. Surety Bonds and Restricted Cash As the owner of the Marshall Mine, the Company was required to post a surety bond with a regulatory commission. As of December 31, 2022, the Company posted a $16.6 million surety bond that was released upon all of the Conditions for closing the MM Transaction being satisfied, which occurred on March 27, 2023. As the owner of the Five Forks Mine, the Company is required to post a surety bond with a regulatory commission. As of March 31, 2023 and December 31, 2022 , the Company had posted a $7.5 million surety bond related to performance requirements associated with the Five Forks Mine. As of March 31, 2023 and December 31, 2022, the Company posted cash collateral of $10.0 million as required by the Company's surety bond provider, which is reported as long-term restricted cash on the Condensed Consolidated Balance Sheets. In April 2023, the Company and the surety bond provider agreed to reduce the cash collateral to $7.7 million. As the lessee of the land adjacent to the Corbin Facility, the Company was required to post surety bonds with a regulatory commission for reclamation. As of March 31, 2023, the amount of these surety bonds was $3.0 million. Tinuum Group In addition to those obligations described in Note 10, the Company has certain limited obligations contingent upon future events in connection with the activities of Tinuum Group. The Company, NexGen Refined Coal, LLC ("NexGen") and two entities affiliated with NexGen have provided an affiliate of the Goldman Sachs Group, Inc. with limited guaranties (the "Tinuum Group Party Guaranties") related to certain losses it may suffer as a result of inaccuracies or breach of representations and covenants committed by Tinuum Group. The Company also is a party to a contribution agreement with NexGen under which any party called upon to pay on a Tinuum Group Party Guaranty is entitled to receive contributions from the other party equal to 50% of the amount paid. The Company has not recorded a liability or expense provision related to this contingent obligation as it believes that it is not probable that a loss will occur with respect to the Tinuum Group Party Guaranties. Legal Proceedings

Supplemental Financial Informat

Supplemental Financial Information	3 Months Ended
	Mar. 31, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Supplemental Financial Information	Supplemental Financial Information Supplemental Balance Sheet Information The following table summarizes the components of Other long-term assets, net as presented in the Condensed Consolidated Balance Sheets: As of (in thousands) March 31, December 31, Other long-term assets, net: Right of use assets, operating leases, net $ 10,122 $ 7,734 Intangible assets, net 8,424 847 Spare parts, net 7,444 6,789 Upfront Customer Consideration 6,348 6,475 Mine development costs, net 5,657 5,478 Mine reclamation asset, net 1,616 1,641 Other 2,174 1,683 Total other long-term assets, net $ 41,785 $ 30,647 Mine development costs include acquisition costs, the cost of other development work and mitigation costs related to the Five Forks Mine and are depleted over the estimated life of the related mine reserves. The Company performs an evaluation of the recoverability of the carrying value of mine development costs to determine if facts and circumstances indicate that their carrying value may be impaired and if any adjustment is warranted. There were no indicators of impairment as of March 31, 2023. Spare parts include critical spares required to support plant operations. Parts and supply costs are determined using the lower of cost or estimated replacement cost. Parts are recorded as maintenance expenses in the period in which they are consumed or are capitalized if applicable. Mine reclamation asset, net represents an asset retirement obligation ("ARO") asset related to the Five Forks Mine and is depreciated over its estimated life. As of March 31, 2023 and December 31, 2022, Other includes the Highview Investment in the amount of $0.6 million and $0.6 million, respectively, that is carried at cost, less impairment, plus or minus observable changes in price for identical or similar investments of the same issuer. Fair value measurements, if any, represent Level 2 measurements. The Highview Investment is evaluated for indicators of impairment such as an event or change in circumstances that may have a significant adverse effect on the fair value of the investment. There were no changes to the carrying value of the Highview Investment for the three months ended March 31, 2023 as there were no indicators of impairment or observable price changes for identical or similar investments. The following table details the components of Other current liabilities and Other long-term liabilities as presented in the Condensed Consolidated Balance Sheets: As of (in thousands) March 31, December 31, Other current liabilities: Current portion of operating lease obligations $ 2,554 $ 2,724 Income and other taxes payable 866 1,039 Current portion of mine reclamation liability 163 548 Other (1) 2,605 2,334 Total other current liabilities $ 6,188 $ 6,645 Other long-term liabilities: Operating lease obligations, long-term $ 7,642 $ 5,133 Mine reclamation liabilities 5,259 7,985 Other 746 733 Total other long-term liabilities $ 13,647 $ 13,851 (1) Included in Other current liabilities is $1.7 million related to the Repayment Agreement as defined in Note 10. As of March 31, 2023 and December 31, 2022, the Mine reclamation liability related to the Five Forks Mine is included in Other long-term liabilities. As of December 31, 2022, the Mine reclamation liability related to Marshall Mine was included in Other current liabilities and Other long-term liabilities. As part of the Arq Acquisition, the Company assumed asset retirement obligations related to two sites; a coal waste site adjacent to the Corbin Facility (the "Corbin ARO") and an inactive mine located in West Virginia (the "Mine 4 ARO"). The Company recorded these AROs at their estimated fair values and periodically adjusts them to reflect changes in the estimated present value resulting from the passage of time and revisions to the estimates of either the timing or amount of the reclamation costs. The Corbin ARO was included in Other long-term liabilities and the current portion of the Mine 4 ARO was included in Other current liabilities with the long-term portion included in Other long-term liabilities. The Mine reclamation liabilities represent AROs and changes for the three months ended March 31, 2023 and year ended December 31, 2022 were as follows: As of (in thousands) March 31, 2023 December 31, 2022 Asset retirement obligations, beginning of period $ 8,533 $ 9,959 Asset retirement obligations assumed (1) 1,500 — Accretion 168 611 Liabilities settled (2) (4,779) (2,071) Changes due to scope and timing of reclamation — 34 Asset retirement obligations, end of period 5,422 8,533 Less current portion 163 548 Asset retirement obligations, long-term $ 5,259 $ 7,985 (1) Represents two asset retirement obligations assumed as part of the Arq Acquisition; $0.5 million related to Corbin ARO and $1.0 million related to Mine 4 ARO. (2) Represent the removal of the Marshall Mine ARO as a result of the MM Transaction as further discussed in Note 3. The following table details the components of "Interest expense" in the Condensed Consolidated Statement of Operations: Three Months Ended March 31, (in thousands) 2023 2022 Interest on Term Loan $ 261 $ — Interest on Arq Loan 98 — Amortization of debt discounts and debt issuance costs 94 — Other 81 86 $ 534 $ 86

Equity Method Investments

Equity Method Investments	3 Months Ended
	Mar. 31, 2023
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	Equity Method Investments Tinuum Group, LLC As of March 31, 2023 and December 31, 2022, the Company's ownership interest in Tinuum Group was 42.5%. For the three months ended March 31, 2023 and the three months ended March 31, 2022, the Company recognized earnings from Tinuum Group of $0.6 million and $1.0 million, respectively, which was comprised solely of cash distributions received during these periods. In December 2022, the Company, certain of the other owners of Tinuum Group (collectively, the "Tinuum Group Owners") and Tinuum Group executed the Distribution and Repayment Agreement (the "Repayment Agreement"). Under the terms of the Repayment Agreement, the Tinuum Group Owners receive cash distributions (the "Distributions") equal to their percentage ownership and also are contractually liable for certain contingent liabilities of Tinuum Group (the "Tinuum Group Obligation") in amounts equal to their percentage ownership. In December 2022, the Company received its percentage share of the Distributions in the amount of $2.0 million and became contractually liable for $1.7 million of the Tinuum Group Obligation. As of March 31, 2023 and December 31, 2022, the Company' portion of the Tinuum Group Obligation is $1.7 million and $1.7 million, respectively and is included in the "Other current liabilities" line item in the Condensed Consolidated Balance Sheets. In the event that the Tinuum Group Obligation is discharged in its entirety or settled for an amount that is less than the total Tinuum Group Obligation, the Company will recognize future equity earnings for the difference in its portion of the Tinuum Group Obligation and its pro rata share of the actual payment made by Tinuum Group, if any, for the Tinuum Group Obligation. In December 2022, the Company and Tinuum Group entered into an agreement (the "Tinuum Group Royalty Agreement") whereby the Company pays Tinuum Group a royalty (the "Tinuum Group Royalty") for certain of the Company's sales of its M-Prove TM products after the expiration of the Section 45 Tax Credit Program (beginning January 1, 2022) to certain of the former refined coal facilities owned by Tinuum Group and operated by Tinuum Services (the "M-45 Facilities"). The Tinuum Group Royalty is calculated based on "Net Profit" (as defined in the Tinuum Royalty Agreement) on the Company's sales of M-Prove TM product to certain of the M-45 Facilities. The Tinuum Group Royalty Agreement is for an initial term of five years with automatic renewals of five years unless the Company and Tinuum Group agree to terminate it. For the three months ended March 31, 2023, the Company recognized $0.2 million of Tinuum Group Royalties, which are included in the "Consumables cost of revenues, excluding depreciation and amortization" line item in the Consolidated Statement of Operations. Tinuum Services, LLC As of March 31, 2023 and December 31, 2022, the Company has a 50% voting and economic interest in Tinuum Services and the carrying value of the equity investment in Tinuum Services was zero and zero, respectively. For the three months ended March 31, 2023 and the three months ended March 31, 2022, the Company recognized losses from Tinuum Services of zero and $0.2 million, respectively. Cash Distributions The following table details the components of the cash distributions from the Company's respective equity method investments included as a component of cash flows from operating activities and investing activities in the Condensed Consolidated Statements of Cash Flows. Distributions from equity method investees are reported in the Condensed Consolidated Statements of Cash Flows as "Distributions from equity method investees, return on investment" as a component of cash flows from operations until such time as the carrying value in an equity method investee company is reduced to zero. Thereafter, such distributions are reported as "Distributions from equity method investees in excess of cumulative earnings" as a component of cash flows from investing activities. Three Months Ended March 31, (in thousands) 2023 2022 Distributions from equity method investees, return on investment Tinuum Services $ — $ 1,501 Tinuum Group — — $ — $ 1,501 Distributions from equity method investees in excess of investment basis Tinuum Group $ 638 $ 1,012 Other — 1 $ 638 $ 1,013

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2023
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity Arq Acquisition and PIPE Investment On February 1, 2023, the Company issued 3,814,864 and 3,842,315 shares of its Common Stock pursuant to the Arq Acquisition and the PIPE Investment, respectively. In addition, the Company issued 5,294,462 Preferred Shares pursuant to the Arq Acquisition, which is classified and presented outside of Stockholders' Equity as Redeemable preferred stock in the Consolidated Balance Sheet as of March 31, 2023. As consideration for the Term Loan, the Company issued 325,857 Warrant Shares, which were deemed to be equity securities and were recorded at their estimated fair value of $0.8 million to Additional paid in capital, with a corresponding amount recorded as debt discount on the Term Loan. Dividend On March 31, 2023, the Company declared a dividend of 68,464 Series A PIK Shares with respect to the accrued dividends on the Series A Preferred Stock for the first quarter of 2023 (the "First Quarter PIK Dividend"). The First Quarter PIK Dividend was recorded at the estimated fair value of $0.2 million as of March 31, 2023 and was paid on April 21, 2023. Stock Repurchase Program As of March 31, 2023, the Company had $7.0 million remaining under a stock repurchase program, which will remain in effect until all amounts are utilized or is otherwise modified by the Board. Tax Asset Protection Plan U.S. federal income tax rules, and Section 382 of the Internal Revenue Code in particular, could substantially limit the use of net operating losses and tax credits if the Company experiences an "ownership change" (as defined in the Internal Revenue Code). In general, an ownership change occurs if there is a cumulative change in the ownership of the Company by "5 percent stockholders" that exceeds 50 percentage points over a rolling three-year period. An entity that experiences an ownership change generally will be subject to an annual limitation on its pre-ownership change tax loss and credit carryforwards equal to the equity value of the entity immediately before the ownership change, multiplied by the long-term, tax-exempt rate posted monthly by the Internal Revenue Service (subject to certain adjustments). The annual limitation would be increased each year to the extent that there is an unused limitation in a prior year.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2023
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation The Company grants equity-based awards to employees, non-employee directors and consultants that may include, but are not limited to, RSAs, PSUs, restricted stock units and stock options. Stock-based compensation expense related to manufacturing employees and administrative employees is included within the "Cost of revenue" and "Payroll and benefits" line items, respectively, in the Condensed Consolidated Statements of Operations. Stock-based compensation expense related to non-employee directors and consultants is included within the "General and administrative" line item in the Condensed Consolidated Statements of Operations. Total stock-based compensation expense for the three months ended March 31, 2023 and 2022 was as follows: Three Months Ended March 31, (in thousands) 2023 2022 RSA expense $ 488 $ 427 PSU expense 75 37 Total stock-based compensation expense $ 563 $ 464 The amount of unrecognized compensation cost as of March 31, 2023, and the expected weighted-average period over which the cost will be recognized is as follows: As of March 31, 2023 (in thousands, expect years) Unrecognized Compensation Cost Expected Weighted- RSA expense $ 2,897 2.45 PSU expense 485 2.49 Total unrecognized stock-based compensation expense $ 3,382 2.46 Restricted Stock Restricted stock is typically granted with vesting terms of three years. The fair value of RSAs is determined based on the closing price of the Company’s common stock on the authorization date of the grant multiplied by the number of shares subject to the stock award. Compensation expense for RSAs is generally recognized on a straight-line basis over the entire vesting period. A summary of RSA activity under the Company's various stock compensation plans for the three months ended March 31, 2023 is presented below: Restricted Stock Weighted-Average Grant Date Fair Value Non-vested at January 1, 2023 652,962 $ 5.58 Granted 498,541 $ 1.97 Vested (237,185) $ 5.67 Forfeited (15,299) $ 5.45 Non-vested at March 31, 2023 899,019 $ 3.55 Performance Share Units Compensation expense is recognized for PSUs on a straight-line basis over the applicable service period, which is generally three years, based on the estimated fair value at the date of grant using a Monte Carlo simulation model. A summary of PSU activity for the three months ended March 31, 2023 is presented below: Units Weighted-Average Aggregate Intrinsic Value (in thousands) Weighted-Average PSUs outstanding, January 1, 2023 148,591 $ 7.85 Granted 231,242 2.48 Vested / Settled (1) (41,855) 6.17 Forfeited / Canceled — — PSUs outstanding, March 31, 2023 337,978 $ 4.38 $ 669 2.49 (1) The number of units shown in the table above are based on target performance. The final number of shares of common stock issued may vary depending on the achievement of market conditions established within the awards, which could result in the actual number of shares issued ranging from zero to a maximum of two times the number of units shown in the above table. For the three months ended March 31, 2023, no shares of common stock were issued upon vesting of PSUs.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes For the three months ended March 31, 2023 and 2022, the Company's income tax expense and effective tax rates were: Three Months Ended March 31, (in thousands, except for rate) 2023 2022 Income tax benefit $ 33 $ — Effective tax rate — % — % The Company incurred pretax loss for the three months ended March 31, 2023 and expects to incur pretax loss for the year ending December 31, 2023. As a result, the effective rate for the three months ended March 31, 2023 was zero as the resultant tax benefit was offset by a valuation allowance recorded as of March 31, 2023. The Company assesses a valuation allowance recorded against deferred tax assets at each reporting date. The determination of whether a valuation allowance for deferred tax assets is appropriate requires the evaluation of positive and negative evidence that can be objectively verified. Consideration must be given to all sources of taxable income available to realize deferred tax assets, including, as applicable, the future reversal of existing temporary differences, future taxable income forecasts exclusive of the reversal of temporary differences and carryforwards, taxable income in carryback years and tax planning strategies. In estimating income taxes, the Company assesses the relative merits and risks of the appropriate income tax treatment of transactions taking into account statutory, judicial and regulatory guidance.

Basis of Presentation (Policies

Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	The accompanying Condensed Consolidated Financial Statements of ADES are unaudited and have been prepared in conformity with accounting principles generally accepted in the United States ("U.S. GAAP") and with Article 10 of Regulation S-X of the Securities and Exchange Commission. In compliance with those instructions, certain information and footnote disclosures normally included in annual consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. The unaudited Condensed Consolidated Financial Statements of ADES in this quarterly report ("Quarterly Report") are presented on a consolidated basis and include ADES and its wholly-owned subsidiaries (collectively, the "Company"). Also included within the unaudited Condensed Consolidated Financial Statements are the Company's unconsolidated equity investments, Tinuum Group and Tinuum Services, which are accounted for under the equity method of accounting, and Highview Enterprises Limited (the "Highview Investment"), which is accounted for in accordance with U.S. GAAP applicable to equity investments that do not qualify for the equity method of accounting. Results of operations and cash flows for the interim periods are not necessarily indicative of the results that may be expected for the entire year. All significant intercompany transactions and accounts were eliminated in consolidation for all periods presented in this Quarterly Report. In the opinion of management, these Condensed Consolidated Financial Statements include all normal and recurring adjustments considered necessary for a fair presentation of the results of operations, financial position, stockholders' equity and cash flows for the interim periods presented. These Condensed Consolidated Financial Statements should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2022 (the "2022 Form 10-K"). Significant accounting policies disclosed therein have not changed.
Earnings (Loss) Per Share	Basic earnings (loss) per share is computed using the weighted-average number of shares of common stock outstanding during the reporting period. Diluted earnings (loss) per share is computed in a manner consistent with that of basic earnings per share, while considering other potentially dilutive securities. For the three months ended March 31, 2023 and 2022, potentially dilutive securities consist of unvested restricted stock awards ("RSAs") and contingent performance stock units ("PSUs"). For the three months ended March 31, 2023 potentially dilutive securities also consist of outstanding shares of Series A Preferred Stock, which contain non-forfeitable rights to earnings and dividends in the form of cash or shares of Series A Preferred Stock (the "Preferred Dividends"), determined at the option of the Company, and are deemed to be participating securities ("Participating Securities"). As permitted, the Company has elected not to separately present basic or diluted earnings (loss) per share attributable to Participating Securities in the Consolidated Statement of Operations for the three months ended March 31, 2023.
Use of Estimates	The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. There have been no changes in the Company’s critical accounting estimates from those that were disclosed in the 2022 Form 10-K. Actual results could differ from these estimates.
Risks and Uncertainties	For 2023, the Company is principally dependent on the operations of its APT business and its cash on hand to provide liquidity over the near and long term. The Company's revenues, sales volumes, earnings and cash flows are significantly affected by prices of competing power generation sources such as natural gas and renewable energy. During periods of low natural gas prices, natural gas provides a competitive alternative to coal-fired power generation and therefore, coal consumption for purposes of power generation may be reduced, which in turn reduces the demand for the Company's products. However, during periods of higher prices for competing power generation sources, there is an increase in coal consumption and thus demand for the Company's products also increases. In addition, coal consumption for purposes of power generation and demand for the Company's products are affected by the demand for electricity, which is higher in the warmer and colder months of the year. As a result, the Company's interim period results are subject to seasonal variations whereby its revenues and cost of revenues tend to be higher in its first and third fiscal quarters compared to its second and fourth fiscal quarters. Abnormal temperatures during the summer and winter months may significantly affect coal consumption and impurities within various municipalities' water sources, and thus impact the demand for the Company's products.
Concentration of credit risk	The Company is exposed to concentrations of credit risk primarily related to cash held at financial institutions and accounts receivable. The Company regularly monitors its credit risk to mitigate the possibility of current and future exposures resulting in a loss. Historically, the losses related to credit risk have been immaterial. The Company evaluates the creditworthiness of its customers prior to entering into agreements to sell its products and, as necessary, throughout the life of the customer relationship.
Reclassifications	Certain balances have been reclassified from the prior year to conform to the current year presentation. Such reclassifications had no effect on the Company’s results of operations or financial position in any of the periods presented.
New Accounting Standards	Effective January 1, 2023, the Company adopted ASU 2016-13, Financial Instruments - Credit Losses (Topic 326) Measurement of Credit Losses on Financial Instruments ("ASU 2016-13"). The main objective of ASU 2016-13 is to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. The adoption of ASU 2016-13 did not have a material impact on the Company's financial statements and disclosures.

Basis of Presentation (Tables)

Basis of Presentation (Tables)	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table sets forth the calculations of basic and diluted loss per share: Three Months Ended March 31, (in thousands, except per share amounts) 2023 2022 Net loss $ (7,508) $ (3,033) Less: Dividends declared on redeemable preferred stock 157 — Loss attributable to common stockholders $ (7,665) $ (3,033) Basic weighted-average common shares outstanding 23,770 18,344 Add: dilutive effect of equity instruments — — Diluted weighted-average shares outstanding 23,770 18,344 Loss per share - basic $ (0.32) $ (0.17) Loss per share - diluted $ (0.32) $ (0.17)

Arq Acquisition (Tables)

Arq Acquisition (Tables)	3 Months Ended
	Mar. 31, 2023
Business Combination and Asset Acquisition [Abstract]
Schedule of Purchase Price Allocation	The following table provides the preliminary estimated fair values of the assets acquired and liabilities assumed as of the Acquisition Date: (in thousands) Purchase Price Allocation Fair value of assets acquired: Cash $ 1,411 Prepaid expenses and other current assets 2,229 Restricted cash, long-term 814 Property, plant and equipment, net 39,159 Other long-term assets, net 11,717 Amount attributable to assets acquired 55,330 Fair Value of liabilities assumed: Accounts payable and accrued expenses 9,806 Current portion of long-term debt 494 Other current liabilities 103 Long-term debt, net of current portion 9,199 Other long-term liabilities 4,523 Amount attributable to liabilities assumed 24,125 Net assets acquired $ 31,205 The following represents the intangible asset identified as part of the Arq Acquisition and which is included in "Other long-term-assets, net" in the table above: (in thousands) Amount Weighted Average Useful Life (years) Developed technology $ 7,700 20
Schedule of Revenues and Income Before Income Taxes	The amounts of revenues and net loss for Arq for the period from the Acquisition Date to March 31, 2023 are as follows: Three Months Ended March 31, (in thousands) 2023 Revenues $ — Net loss $ (3,650)
Schedule of Pro Forma Information	Since Arq had no revenues for the three months ended March 31, 2023 or 2022, pro forma revenues are the same as the Company's reported revenues for those periods. Three Months Ended March 31, (in thousands) 2023 2022 Revenues $ 20,805 $ 26,402 Net loss $ (4,069) $ (13,009)

Revenues (Tables)

Revenues (Tables)	3 Months Ended
	Mar. 31, 2023
Revenue from Contract with Customer [Abstract]
Schedule of Accounts Receivables	The following table shows the components of the Company's Receivables, net: As of (in thousands) March 31, 2023 December 31, 2022 Trade receivables, net $ 9,989 $ 13,789 Other receivables 72 75 Receivables, net $ 10,061 $ 13,864

Inventories, net (Tables)

Inventories, net (Tables)	3 Months Ended
	Mar. 31, 2023
Inventory Disclosure [Abstract]
Schedule of Inventory	The following table summarizes the Company's inventories recorded at the lower of average cost or net realizable value, as of March 31, 2023 and December 31, 2022: As of (in thousands) March 31, 2023 December 31, 2022 Product inventory, net $ 10,356 $ 9,479 Raw material inventory 9,876 8,349 Total inventories, net $ 20,232 $ 17,828

Debt Obligations (Tables)

Debt Obligations (Tables)	3 Months Ended
	Mar. 31, 2023
Debt Disclosure [Abstract]
Schedule of Borrowings	As of (in thousands) March 31, 2023 December 31, 2022 Term Loan due February 2027, related party $ 10,000 $ — Arq Loan due January 2036 9,960 — Finance lease obligations 4,287 4,581 24,247 4,581 Unamortized debt discounts (1,288) — Unamortized debt issuance costs (1,229) — 21,730 4,581 Less: Current maturities (1,611) (1,131) Total long-term debt obligations $ 20,119 $ 3,450

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2023
Leases [Abstract]
Schedule of Operating and Finance Lease Right-Of-Use ("ROU") Assets and Liabilities	The Company's operating and finance lease right-of-use ("ROU") assets and liabilities as of March 31, 2023 and December 31, 2022 consisted of the following items (in thousands): As of Leases March 31, 2023 December 31, 2022 Operating Leases Operating lease right-of-use assets, net of accumulated amortization (1) $ 10,122 $ 7,734 Operating lease obligations, current $ 2,554 $ 2,724 Long-term operating lease obligations 7,642 5,133 Total operating lease obligation $ 10,196 $ 7,857 Finance Leases Finance lease right-of-use assets, net of accumulated amortization (2) $ 2,343 $ 2,565 Finance lease obligations, current $ 1,117 $ 1,131 Long-term finance lease obligations 3,170 3,450 Total finance lease obligations $ 4,287 $ 4,581 (1) Operating lease ROU assets are reported net of accumulated amortization of $5.1 million and $4.4 million as of March 31, 2023 and December 31, 2022, respectively. (2) Finance lease ROU assets are reported net of accumulated amortization of $2.2 million and $2.0 million as of March 31, 2023 and December 31, 2022, respectively. Lease financial information as of and for the three months ended March 31, 2023 and 2022 is provided in the following table: Three Months Ended March 31, (in thousands) 2023 2022 Finance lease cost: Amortization of right-of-use assets $ 223 $ 141 Interest on lease liabilities 307 78 Operating lease cost 982 806 Short-term lease cost 409 243 Variable lease cost (1) 8 9 Total lease cost $ 1,929 $ 1,277 Other Information: Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for finance leases $ 307 $ 78 Operating cash flows for operating leases $ 787 $ 738 Financing cash flows for finance leases $ 295 $ 226 Right-of-use assets obtained in exchange for new finance lease liabilities $ — $ — Right-of-use assets obtained in exchange for new operating lease liabilities $ — $ 3,418 Weighted-average remaining lease term - finance leases 2.5 years 2.7 years Weighted-average remaining lease term - operating leases 7.7 years 4.4 years Weighted-average discount rate - finance leases 5.9 % 6.3 % Weighted-average discount rate - operating leases 9.8 % 6.0 % (1) Primarily includes common area maintenance, property taxes and insurance payable to lessors.

Supplemental Financial Inform_2

Supplemental Financial Information (Tables)	3 Months Ended
	Mar. 31, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Long Term Assets	The following table summarizes the components of Other long-term assets, net as presented in the Condensed Consolidated Balance Sheets: As of (in thousands) March 31, December 31, Other long-term assets, net: Right of use assets, operating leases, net $ 10,122 $ 7,734 Intangible assets, net 8,424 847 Spare parts, net 7,444 6,789 Upfront Customer Consideration 6,348 6,475 Mine development costs, net 5,657 5,478 Mine reclamation asset, net 1,616 1,641 Other 2,174 1,683 Total other long-term assets, net $ 41,785 $ 30,647
Schedule of Other Liabilities	The following table details the components of Other current liabilities and Other long-term liabilities as presented in the Condensed Consolidated Balance Sheets: As of (in thousands) March 31, December 31, Other current liabilities: Current portion of operating lease obligations $ 2,554 $ 2,724 Income and other taxes payable 866 1,039 Current portion of mine reclamation liability 163 548 Other (1) 2,605 2,334 Total other current liabilities $ 6,188 $ 6,645 Other long-term liabilities: Operating lease obligations, long-term $ 7,642 $ 5,133 Mine reclamation liabilities 5,259 7,985 Other 746 733 Total other long-term liabilities $ 13,647 $ 13,851 (1) Included in Other current liabilities is $1.7 million related to the Repayment Agreement as defined in Note 10.
Schedule of Change in Asset Retirement Obligation	The Mine reclamation liabilities represent AROs and changes for the three months ended March 31, 2023 and year ended December 31, 2022 were as follows: As of (in thousands) March 31, 2023 December 31, 2022 Asset retirement obligations, beginning of period $ 8,533 $ 9,959 Asset retirement obligations assumed (1) 1,500 — Accretion 168 611 Liabilities settled (2) (4,779) (2,071) Changes due to scope and timing of reclamation — 34 Asset retirement obligations, end of period 5,422 8,533 Less current portion 163 548 Asset retirement obligations, long-term $ 5,259 $ 7,985 (1) Represents two asset retirement obligations assumed as part of the Arq Acquisition; $0.5 million related to Corbin ARO and $1.0 million related to Mine 4 ARO. (2) Represent the removal of the Marshall Mine ARO as a result of the MM Transaction as further discussed in Note 3.
Schedule of "Interest expense" in the Condensed Consolidated Statement of Operations	The following table details the components of "Interest expense" in the Condensed Consolidated Statement of Operations: Three Months Ended March 31, (in thousands) 2023 2022 Interest on Term Loan $ 261 $ — Interest on Arq Loan 98 — Amortization of debt discounts and debt issuance costs 94 — Other 81 86 $ 534 $ 86

Equity Method Investments (Tabl

Equity Method Investments (Tables)	3 Months Ended
	Mar. 31, 2023
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Equity Method Investments	The following table details the components of the cash distributions from the Company's respective equity method investments included as a component of cash flows from operating activities and investing activities in the Condensed Consolidated Statements of Cash Flows. Distributions from equity method investees are reported in the Condensed Consolidated Statements of Cash Flows as "Distributions from equity method investees, return on investment" as a component of cash flows from operations until such time as the carrying value in an equity method investee company is reduced to zero. Thereafter, such distributions are reported as "Distributions from equity method investees in excess of cumulative earnings" as a component of cash flows from investing activities. Three Months Ended March 31, (in thousands) 2023 2022 Distributions from equity method investees, return on investment Tinuum Services $ — $ 1,501 Tinuum Group — — $ — $ 1,501 Distributions from equity method investees in excess of investment basis Tinuum Group $ 638 $ 1,012 Other — 1 $ 638 $ 1,013

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2023
Share-Based Payment Arrangement [Abstract]
Schedule of Allocation of Compensation Expense	Total stock-based compensation expense for the three months ended March 31, 2023 and 2022 was as follows: Three Months Ended March 31, (in thousands) 2023 2022 RSA expense $ 488 $ 427 PSU expense 75 37 Total stock-based compensation expense $ 563 $ 464
Schedule of Unrecognized Compensation Cost	The amount of unrecognized compensation cost as of March 31, 2023, and the expected weighted-average period over which the cost will be recognized is as follows: As of March 31, 2023 (in thousands, expect years) Unrecognized Compensation Cost Expected Weighted- RSA expense $ 2,897 2.45 PSU expense 485 2.49 Total unrecognized stock-based compensation expense $ 3,382 2.46
Schedule of Restricted Stock Activity	A summary of RSA activity under the Company's various stock compensation plans for the three months ended March 31, 2023 is presented below: Restricted Stock Weighted-Average Grant Date Fair Value Non-vested at January 1, 2023 652,962 $ 5.58 Granted 498,541 $ 1.97 Vested (237,185) $ 5.67 Forfeited (15,299) $ 5.45 Non-vested at March 31, 2023 899,019 $ 3.55
Schedule of Performance Shares Units	A summary of PSU activity for the three months ended March 31, 2023 is presented below: Units Weighted-Average Aggregate Intrinsic Value (in thousands) Weighted-Average PSUs outstanding, January 1, 2023 148,591 $ 7.85 Granted 231,242 2.48 Vested / Settled (1) (41,855) 6.17 Forfeited / Canceled — — PSUs outstanding, March 31, 2023 337,978 $ 4.38 $ 669 2.49 (1) The number of units shown in the table above are based on target performance. The final number of shares of common stock issued may vary depending on the achievement of market conditions established within the awards, which could result in the actual number of shares issued ranging from zero to a maximum of two times the number of units shown in the above table. For the three months ended March 31, 2023, no shares of common stock were issued upon vesting of PSUs.

Income Taxes (Tables)

Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Schedule of Income Tax Expense and Effective Tax Rates	For the three months ended March 31, 2023 and 2022, the Company's income tax expense and effective tax rates were: Three Months Ended March 31, (in thousands, except for rate) 2023 2022 Income tax benefit $ 33 $ — Effective tax rate — % — %

Basis of Presentation - Acquisi

Basis of Presentation - Acquisition (Narrative) (Details) - Arq Limited $ / shares in Units, $ in Millions	Feb. 01, 2023 USD ($) $ / shares shares
Business Acquisition [Line Items]
Consideration transferred | $	$ 31.2
Series A Preferred Stock
Business Acquisition [Line Items]
Business acquisition, equity interest issued or issuable (in dollars per share) | $ / shares	$ 0.001
Common Stock
Business Acquisition [Line Items]
Business acquisition, issued number of shares (in shares) | shares	3,814,864
Business acquisition, equity interest issued or issuable (in dollars per share) | $ / shares	$ 0.001
Preferred Stock
Business Acquisition [Line Items]
Business acquisition, issued number of shares (in shares) | shares	5,294,462

Basis of Presentation - Loan Ag

Basis of Presentation - Loan Agreement and Equity Financing (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	Feb. 01, 2023	Mar. 31, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unamortized discount		$ 1,288	$ 0
Debt issuance costs		$ 9,960	$ 0
Issuance of warrant	325,857
Consideration received on transaction	$ 15,400
Price per share (in dollars per share)	$ 4
Warrant
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan term	7 years
CF Global Credit, LP
Accounts, Notes, Loans and Financing Receivable [Line Items]
Issuance of warrant	325,457,000
Warrant shares, percent of fully diluted share capital	1%
Exercise price of warrants (in dollars per share)	$ 0.01
Secured Debt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from issuance of debt	$ 10,000
Unamortized discount	200
Net cash proceeds	8,500
Debt issuance costs	$ 1,300
Exercise price of warrants (in dollars per share)	$ 0.01
Loan term	48 months

Basis of Presentation - Schedul

Basis of Presentation - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Accounting Policies [Abstract]
Net loss	$ (7,508)	$ (3,033)
Less: Dividends declared on redeemable preferred stock	157	0
Loss attributable to common stockholders, basic	(7,665)	(3,033)
Loss attributable to common stockholders, diluted	$ (7,665)	$ (3,033)
Basic weighted-average common shares outstanding (in shares)	23,770	18,344
Add: dilutive effect of equity instruments (in shares)	0	0
Diluted weighted-average shares outstanding (in shares)	23,770	18,344
Loss per share - basic (in dollars per share)	$ (0.32)	$ (0.17)
Loss per share - diluted (in dollars per share)	$ (0.32)	$ (0.17)
Total shares excluded from diluted shares outstanding (in shares)	4,200	300

Basis of Presentation - Concent

Basis of Presentation - Concentration of Credit Risk (Narrative) (Details) $ in Thousands	Mar. 31, 2023 USD ($) financial_institution
Accounting Policies [Abstract]
Number of financial institutions | financial_institution	1
Time deposits, $250,000 or more | $	$ 250

Arq Acquisition - Narrative (De

Arq Acquisition - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended
	Mar. 31, 2023	Feb. 01, 2023	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Business Acquisition [Line Items]
Preferred stock, shares issued (in shares)	0		0		0
Preferred stock par value (in dollars per share)	$ 0.001		$ 0.001		$ 0.001
Series A Preferred Stock
Business Acquisition [Line Items]
Preferred stock dividends declared on redeemable preferred stock (in shares)	68,464
Arq Limited
Business Acquisition [Line Items]
Consideration transferred		$ 31.2
Acquisition related costs		$ 8.7
Preferred stock, shares issued (in shares)		833,914
Preferred stock par value (in dollars per share)		$ 3.46
Contingent consideration, liability		$ 3.3
Increase in payroll and benefits for compensation expense				$ 1.9
Increase in depreciation and amortization			$ 0.2	0.6
Increase in intangible assets			0.1	0.1
Increase in interest expense			$ 0.2	0.3
Reversal of transaction costs				$ 6.6
Arq Limited | Series A Preferred Stock
Business Acquisition [Line Items]
Preferred stock, shares designated (in shares)		8,900,000
Shares issued (in dollars per share)		$ 4
Effective interest rate		8%
Debt instrument, annual increase		2%
PIK shares, fraction rounded to zero		0.5
Debt instrument, redemption price		140%
Arq Limited | Common Stock
Business Acquisition [Line Items]
Business acquisition, issued number of shares (in shares)		3,814,864
Business acquisition, issued number of shares issuable, value		$ 12.4
Arq Limited | Preferred Stock
Business Acquisition [Line Items]
Business acquisition, issued number of shares (in shares)		5,294,462
Business acquisition, issued number of shares issuable, value		$ 18.8

Arq Acquisition - Schedule of P

Arq Acquisition - Schedule of Purchase Price Allocation (Details) - Arq Limited $ in Thousands	Feb. 01, 2023 USD ($)
Business Acquisition [Line Items]
Cash	$ 1,411
Prepaid expenses and other current assets	2,229
Restricted cash, long-term	814
Property, plant and equipment, net	39,159
Other long-term assets, net	11,717
Amount attributable to assets acquired	55,330
Accounts payable and accrued expenses	9,806
Current portion of long-term debt	494
Other current liabilities	103
Long-term debt, net of current portion	9,199
Other long-term liabilities	4,523
Amount attributable to liabilities assumed	24,125
Net assets acquired	31,205
Developed technology
Business Acquisition [Line Items]
Amount	$ 7,700
Weighted Average Useful Life (years)	20 years

Arq Acquisition - Schedule of R

Arq Acquisition - Schedule of Revenues and Income Before Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Business Acquisition [Line Items]
Revenues	$ 20,805	$ 26,402
Net loss	(7,508)	$ (3,033)
Arq Acquisition
Business Acquisition [Line Items]
Revenues	0
Net loss	$ (3,650)

Arq Acquisition - Schedule of_2

Arq Acquisition - Schedule of Pro Forma Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Business Combination and Asset Acquisition [Abstract]
Revenues	$ 20,805	$ 26,402
Net loss	$ (4,069)	$ (13,009)

Marshall Mine (Details)

Marshall Mine (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	May 09, 2023	Mar. 31, 2023	Apr. 30, 2023	Mar. 27, 2023	Dec. 31, 2022
Business Acquisition [Line Items]
Liabilities		$ 53,810			$ 41,185
Restricted cash, noncurrent		10,000			$ 10,000
Marshall Mine
Business Acquisition [Line Items]
Consideration				$ 2,200
Liabilities				$ 4,900
Gain on change in estimate, asset retirement obligation		$ 2,700
Marshall Mine | Subsequent Event
Business Acquisition [Line Items]
Restricted cash	$ 2,300
Restricted cash, noncurrent			$ 7,700

Revenues - Narrative (Details)

Revenues - Narrative (Details)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenue from Contract with Customer [Abstract]
Collection terms	Credit terms are generally net 30 - 45 days from the date of invoice.
Revenue from Contract with Customer Benchmark | Geographic Concentration Risk | Canada
Disaggregation of Revenue [Line Items]
Percent of revenue generated	14%	11%

Revenues - Schedule of Accounts

Revenues - Schedule of Accounts Receivables (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, net	$ 10,061	$ 13,864
Other receivables	72	75
Trade receivables, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables, net	$ 9,989	$ 13,789

Inventories, net (Details)

Inventories, net (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Inventory Disclosure [Abstract]
Product inventory, net	$ 10,356	$ 9,479
Raw material inventory	9,876	8,349
Total inventories, net	$ 20,232	$ 17,828

Debt Obligations - Schedule of

Debt Obligations - Schedule of Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Arq Loan due January 2036	$ 9,960	$ 0
Finance lease obligations	4,287	4,581
Long-term debt	24,247	4,581
Unamortized debt discounts	(1,288)	0
Unamortized debt issuance costs	(1,229)	0
Long-term debt	21,730	4,581
Less: Current maturities	(1,611)	(1,131)
Total long-term debt obligations	20,119	3,450
Term Loan
Debt Instrument [Line Items]
Term Loan due February 2027, related party	$ 10,000	$ 0

Debt Obligations - Narrative (D

Debt Obligations - Narrative (Details)		3 Months Ended
	Feb. 01, 2023 USD ($) $ / shares	Mar. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Jan. 27, 2021 USD ($)
Debt Instrument [Line Items]
Debt instrument, post-transaction from exercise of warrant	1%
Unamortized discount		$ (1,288,000)	$ 0
Debt principal amount				$ 2,000,000
Secured Debt
Debt Instrument [Line Items]
Term	48 months
Debt instrument, covenant loan to value ratio	0.40
Exercise price of warrants (in dollars per share) | $ / shares	$ 0.01
Unamortized discount	$ (200,000)
Secured Debt | Between 1 And 36 Moths
Debt Instrument [Line Items]
Debt instrument, prepayment premium	2%
Secured Debt | Between 37 Months And Maturity Date
Debt Instrument [Line Items]
Debt instrument, prepayment premium	1%
Secured Debt | Adjusted Term SOFR for an Interest Period of One Month in Effect on the Third U.S. Government Securities Business Day
Debt Instrument [Line Items]
Debt instrument, prepayment premium	2%
Secured Debt | Beginning March 31, 2023
Debt Instrument [Line Items]
Debt covenant, minimum cash balance requirement	$ 5,000,000
Secured Debt | Fiscal Year 2023
Debt Instrument [Line Items]
Debt covenant, minimum annual Revenue requirement	70,000,000
Secured Debt | Fiscal Year 2024
Debt Instrument [Line Items]
Debt covenant, minimum annual Revenue requirement	85,000,000
Debt covenant, minimum consolidated EBITDA requirement	3,000,000
Secured Debt | Fiscal Year 2025 and Thereafter
Debt Instrument [Line Items]
Debt covenant, minimum annual Revenue requirement	100,000,000
Debt covenant, minimum consolidated EBITDA requirement	$ 16,000,000
Secured Debt | SOFR
Debt Instrument [Line Items]
Debt instrument, floor rate percentage	1%
Debt instrument, cap rate percentage	2%
Debt instrument, percent of paid in cash	9%
Debt instrument, percent of paid in kind	5%
Secured Debt | SOFR | Adjusted Term SOFR for an Interest Period of One Month in Effect on the Third U.S. Government Securities Business Day
Debt Instrument [Line Items]
Debt instrument, interest rate	14%
Secured Debt | Base Rate
Debt Instrument [Line Items]
Debt instrument, percent of paid in cash	8%
Arq Loan
Debt Instrument [Line Items]
Face amount		10,000,000		8,000,000
Estimated fair value		9,700,000
Unamortized discount		$ (300,000)
Interest and principal payment				$ 100,000
Indebtedness percentage		400%
Debt instrument, annual increase		20%
Equity percentage		1.25
Arq Loan | Penalty Year 2024
Debt Instrument [Line Items]
Prepayment penalty, percentage		3%
Arq Loan | Penalty Year 2025
Debt Instrument [Line Items]
Prepayment penalty, percentage		2%
Arq Loan | Penalty Year 2026
Debt Instrument [Line Items]
Prepayment penalty, percentage		1%
Arq Loan | Bear Interest
Debt Instrument [Line Items]
Debt interest rate				6%
Arq Loan | Prime Rate
Debt Instrument [Line Items]
Debt interest rate				2.75%

Leases - Schedule of Operating

Leases - Schedule of Operating and Finance Lease Right-Of-Use ("ROU") Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Operating Leases
Operating lease right-of-use assets, net of accumulated amortization	$ 10,122	$ 7,734
Operating lease obligations, current	2,554	2,724
Long-term operating lease obligations	7,642	5,133
Total operating lease obligation	10,196	7,857
Finance Leases
Finance lease right-of-use assets, net of accumulated amortization	2,343	2,565
Finance lease obligations, current	1,117	1,131
Long-term finance lease obligations	3,170	3,450
Total finance lease obligations	4,287	4,581
Operating lease, accumulated amortization	5,100	4,400
Finance lease, accumulated amortization	$ 2,200	$ 2,000

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Lessee, Lease, Description [Line Items]
Operating lease, right-of-use asset, statement of financial position [Extensible Enumeration]	Other long-term assets, net		Other long-term assets, net
Operating lease, liability, current, statement of financial position [Extensible List]	Other current liabilities		Other current liabilities
Operating lease, liability, noncurrent, statement of financial position [Extensible List]	Other long-term liabilities		Other long-term liabilities
Operating lease, expense	$ 1.4	$ 1.1
General and Administrative Expense
Lessee, Lease, Description [Line Items]
Operating lease, expense	0.3	0.1
Consumables
Lessee, Lease, Description [Line Items]
Operating lease, expense	$ 1.1	$ 1

Leases - Schedule of Lease Liab

Leases - Schedule of Lease Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Finance lease cost:
Amortization of right-of-use assets	$ 223	$ 141
Interest on lease liabilities	307	78
Operating lease cost	982	806
Short-term lease cost	409	243
Variable lease cost	8	9
Total lease cost	1,929	1,277
Operating cash flows for finance leases	307	78
Operating cash flows for operating leases	787	738
Financing cash flows for finance leases	295	226
Right-of-use assets obtained in exchange for new finance lease liabilities	0	0
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 0	$ 3,418
Weighted-average remaining lease term - finance leases	2 years 6 months	2 years 8 months 12 days
Weighted-average remaining lease term - operating leases	7 years 8 months 12 days	4 years 4 months 24 days
Weighted-average discount rate - finance leases	5.90%	6.30%
Weighted-average discount rate - operating leases	9.80%	6%

Commitments and Contingencies (

Commitments and Contingencies (Details)	1 Months Ended
	Aug. 31, 2022 USD ($)	Mar. 31, 2023 USD ($) entity	Dec. 31, 2022 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Retention liability			$ 1,400,000
Retention agreements amount of retention pay	$ 1,000,000
Other Commitments [Line Items]
Restricted cash, long-term		$ 10,000,000	10,000,000
Tinuum Group, LLC
Related Party Transaction [Line Items]
Number of entities affiliated with related parties | entity		2
Limited guarantees, percent		50%
Liabilities or expense		$ 0
Marshall Mine
Other Commitments [Line Items]
Surety bond amount			16,600,000
Five Forks Mine
Other Commitments [Line Items]
Surety bond amount		7,500,000	$ 7,500,000
Corbin Facilities
Other Commitments [Line Items]
Surety bond amount		$ 3,000,000

Supplemental Financial Inform_3

Supplemental Financial Information - Schedule of Long Term Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Other long-term assets, net:
Right of use assets, operating leases, net	$ 10,122	$ 7,734
Intangible assets, net	8,424	847
Spare parts, net	7,444	6,789
Upfront Customer Consideration	6,348	6,475
Mine development costs, net	5,657	5,478
Mine reclamation asset, net	1,616	1,641
Other	2,174	1,683
Total other long-term assets, net	$ 41,785	$ 30,647

Supplemental Financial Inform_4

Supplemental Financial Information - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Related Party Transaction [Line Items]
Equity method investments	$ 0
Highview Enterprises Limited
Related Party Transaction [Line Items]
Equity method investments	$ 0.6	$ 0.6

Supplemental Financial Inform_5

Supplemental Financial Information - Schedule of Other Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Other current liabilities:
Current portion of operating lease obligations	$ 2,554	$ 2,724
Operating lease, liability, current, statement of financial position [Extensible List]	Total other current liabilities	Total other current liabilities
Income and other taxes payable	$ 866	$ 1,039
Current portion of mine reclamation liability	163	548
Other	2,605	2,334
Total other current liabilities	6,188	6,645
Other long-term liabilities:
Operating lease obligations, long-term	$ 7,642	$ 5,133
Operating lease, liability, noncurrent, statement of financial position [Extensible List]	Total other long-term liabilities	Total other long-term liabilities
Mine reclamation liabilities	$ 5,259	$ 7,985
Other	746	733
Total other long-term liabilities	13,647	$ 13,851
Tinuum Group, LLC
Other current liabilities:
Other	$ 1,700

Supplemental Financial Inform_6

Supplemental Financial Information - Schedule of Change in Asset Retirement Obligation (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2023 USD ($) obligation	Dec. 31, 2022 USD ($)
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligations, beginning of period	$ 8,533	$ 9,959
Asset retirement obligations assumed	1,500	0
Accretion	168	611
Liabilities settled	(4,779)	(2,071)
Changes due to scope and timing of reclamation	0	34
Asset retirement obligations, end of period	5,422	8,533
Less current portion	163	548
Asset retirement obligations, long-term	$ 5,259	7,985
Business Acquisition [Line Items]
Number of asset retirement obligations | obligation	2
Asset retirement obligations assumed	$ 1,500	$ 0
Corbin ARO
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligations assumed	500
Business Acquisition [Line Items]
Asset retirement obligations assumed	500
Mine 4
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligations assumed	1,000
Business Acquisition [Line Items]
Asset retirement obligations assumed	$ 1,000

Supplemental Financial Inform_7

Supplemental Financial Information - Schedule of "Interest expense" in the Condensed Consolidated Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Business Acquisition [Line Items]
Amortization of debt discounts and debt issuance costs	$ 94	$ 0
Other	81	86
Interest expense	534	86
Term Loan
Business Acquisition [Line Items]
Interest on loan	261	0
Arq Loan
Business Acquisition [Line Items]
Interest on loan	$ 98	$ 0

Equity Method Investments - Nar

Equity Method Investments - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Dec. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Schedule of Equity Method Investments [Line Items]
Earnings from equity method investments		$ 638	$ 833
Equity method investments		$ 0
Tinuum Group, LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest, percent	42.50%	42.50%
Earnings from equity method investments		$ 600	1,000
Proceeds from equity method investment, percentage share	$ 2,000
Liabilities assumed	$ 1,700
Recognized royalty		$ 200
Tinuum Services, LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest, percent	50%	50%
Earnings from equity method investments		$ 0	$ (200)
Equity method investments	$ 0

Equity Method Investments - Sch

Equity Method Investments - Schedule of Results of Operations and Summary of Distributions (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Schedule of Equity Method Investments [Line Items]
Distributions from equity method investees, return on investment	$ 0	$ 1,501
Distributions from equity method investees in excess of investment basis	638	1,013
Tinuum Services
Schedule of Equity Method Investments [Line Items]
Distributions from equity method investees, return on investment	0	1,501
Tinuum Group
Schedule of Equity Method Investments [Line Items]
Distributions from equity method investees, return on investment	0	0
Distributions from equity method investees in excess of investment basis	638	1,012
Other
Schedule of Equity Method Investments [Line Items]
Distributions from equity method investees in excess of investment basis	$ 0	$ 1

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ in Thousands				3 Months Ended
	Apr. 21, 2023	Mar. 31, 2023	Feb. 01, 2023	Mar. 31, 2023	Mar. 31, 2022	May 05, 2017
Class of Stock [Line Items]
Issuance of warrant (in shares)			325,857
Estimated fair value			$ 800	$ 826
Paid-in-kind dividend on redeemable preferred stock				$ 157	$ 0
Subsequent Event
Class of Stock [Line Items]
Paid-in-kind dividend on redeemable preferred stock	$ 200
Maximum
Class of Stock [Line Items]
Requirement to own shares outstanding as percent						4.99%
Series A Preferred Stock
Class of Stock [Line Items]
Dividends declared on preferred stock (in shares)		68,464
Common Stock
Class of Stock [Line Items]
Shares issued (in shares)				3,842,315
New shares issued (in shares)			3,842,315	3,814,864
Remaining authorized amount		$ 7,000		$ 7,000
Common Stock | Arq Acquisition
Class of Stock [Line Items]
Shares issued (in shares)			3,814,864
Preferred Stock | Arq Acquisition
Class of Stock [Line Items]
Shares issued (in shares)			5,294,462

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Allocation of Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 563	$ 464
RSA expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	488	427
Performance Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 75	$ 37

Stock-Based Compensation - Sc_2

Stock-Based Compensation - Schedule of Unrecognized Compensation Cost (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	$ 3,382
Expected Weighted- Average Period of Recognition (in years)	2 years 5 months 15 days
RSA expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	$ 2,897
Expected Weighted- Average Period of Recognition (in years)	2 years 5 months 12 days
Performance Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	$ 485
Expected Weighted- Average Period of Recognition (in years)	2 years 5 months 26 days

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details)	3 Months Ended
	Mar. 31, 2023
RSA expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Performance Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years

Stock-Based Compensation - Sc_3

Stock-Based Compensation - Schedule of Restricted Stock Activity (Details) - RSA expense	3 Months Ended
	Mar. 31, 2023 $ / shares shares
Restricted Stock
Non-vested shares, beginning balance (in shares) | shares	652,962
Granted (in shares) | shares	498,541
Vested (in shares) | shares	(237,185)
Forfeited (in shares) | shares	(15,299)
Non-vested shares, ending balance (in shares) | shares	899,019
Weighted-Average Grant Date Fair Value
Non-vested shares, beginning balance (in dollars per share) | $ / shares	$ 5.58
Granted (in dollars per share) | $ / shares	1.97
Vested (in dollars per share) | $ / shares	5.67
Forfeited (in dollars per share) | $ / shares	5.45
Non-vested shares, ending balance (in dollars per share) | $ / shares	$ 3.55

Stock-Based Compensation - Sc_4

Stock-Based Compensation - Schedule of Performance Shares Units (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Weighted-Average Grant Date Fair Value
Common stock, shares issued (in shares)	31,854,636	23,788,319
Performance Share Units
Units
Non-vested shares, beginning balance (in shares)	148,591
Granted (in shares)	231,242
Vested / Settled (in shares)	(41,855)
Forfeited / Canceled (in shares)	0
Non-vested shares, ending balance (in shares)	337,978
Weighted-Average Grant Date Fair Value
Non-vested shares, beginning balance (in dollars per share)	$ 7.85
Granted (in dollars per share)	2.48
Vested / Settled (in dollars per share)	6.17
Forfeited / Canceled (in dollars per share)	0
Non-vested shares, ending balance (in dollars per share)	$ 4.38
Outstanding, aggregate intrinsic value	$ 669
Outstanding, weighted-average remaining contractual term (in years)	2 years 5 months 26 days
Common stock, shares issued (in shares)	0

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income Tax Expense and Effective Tax Rates (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Income tax benefit	$ (33)	$ 0
Effective tax rate	0%	0%

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Effective tax rate	0%	0%