Summary of Operations and Significant Accounting Policies | Summary of Operations and Significant Accounting Policies Nature of Operations Arq Inc. ("Arq" or the "Company", formerly known as Advanced Emissions Solutions, Inc. ("ADES")) is a Delaware corporation with its principal office located in Greenwood Village, Colorado, manufacturing, mining and logistic operations located in Louisiana and mining and manufacturing operations in Kentucky. The Company is an environmental technology company and is principally engaged in the sale of consumable air, water, and soil treatment solutions including activated carbon ("AC") and chemical technologies. The Company's proprietary AC products enable customers to reduce air, water, and soil contaminants, including mercury, per and polyfluoroalkyl substances ("PFAS") and other pollutants, to help our customers 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, municipal water and air, water, and soil treatment and remediation markets (collectively, the advanced purification technologies or "APT" market). In February 2023, the Company acquired 100% of the equity of the subsidiaries of Arq Limited (the "Arq Acquisition," and hereafter the Arq Limited subsidiaries referred to as "Legacy Arq") to secure access to a feedstock, a manufacturing facility and certain patented processes as a means to manufacture additional granular activated carbon ("GAC") products for sale into the APT and other markets. With the Arq Acquisition, the Company now controls bituminous coal waste reserves and owns a manufacturing facility, both located in Corbin Kentucky (the "Corbin Facility"), and a process to recover and purify the bituminous coal fines for sale or further conversion to GAC products. Under this manufacturing process, the Company expects to be able to convert bituminous coal waste into a purified, microfine carbon powder known as Arq powder TM ("Arq Powder"). See further discussion of the Arq Acquisition in Note 2. Principles of Consolidation The Consolidated Financial Statements include accounts of wholly-owned subsidiaries and variable interest entities ("VIEs") in which the Company is the primary beneficiary. All significant intercompany balances and transactions have been eliminated in consolidation. All investments in partially owned entities for which the Company has the ability to exercise significant influence and holds a 20% or greater ownership interest based on the legal form of the Company's ownership percentage are accounted for using the equity method and are included in the Other long-term assets, net line item in the Consolidated Balance Sheets. As of December 31, 2023, the Company holds equity interests of 42.5% and 50.0% in Tinuum Group, LLC ("Tinuum Group") and Tinuum Services, LLC ("Tinuum Services"), respectively. Cash and restricted cash Cash consists of cash on hand and bank deposits. Restricted cash is primarily comprised of posted cash collateral required under a surety bond contract related to a lignite mine in Louisiana (the "Five Forks Mine") and the Corbin Facility. Concentration of credit risk As of December 31, 2023, the Company holds cash that exceed the Federal Deposit Insurance Corporation ("FDIC") limits (currently $250 thousand) at two financial institutions. If a financial institution was unable to perform its obligations, the Company would be at risk regarding the amount of cash held in excess of the FDIC limits. Fair value measurements The carrying amounts of our cash, restricted cash, accounts receivable, accounts payable and other current liabilities approximate fair value as recorded due to the short-term nature of these instruments. Receivables, net Receivables, net are recorded at net realizable value, which includes an appropriate allowance for estimated uncollectible amounts to reflect any loss anticipated on the receivables. Increases and decreases in the allowance for doubtful accounts are established based upon changes in the credit quality of receivables and are included as a component of the General and administrative line item in the Consolidated Statements of Operations. The allowance for doubtful accounts is based on historical experience, general economic conditions and the credit quality of specific accounts and was not material as of December 31, 2023 and 2022. Inventories, net The cost of inventory is determined using the average cost method. Inventories, net are stated at the lower of average cost or net realizable value and consist principally of raw materials and finished goods related to the Company's AC products. Inventories are periodically reviewed for both potential obsolescence and potential declines in anticipated selling prices. The Company makes assumptions about the future demand for and market value of the inventory and estimates the amount of any obsolete, unmarketable, slow moving or overvalued inventory. The composition of Inventories is included in Note 3. Intangible Assets Intangible assets consist of customer relationships, patents, and developed technology. The Company has developed technologies resulting in patents being granted by the U.S. Patent and Trademark Office or other regulatory offices. Legal costs associated with securing the patent are capitalized and amortized over the legal or useful life beginning on the patent filing date. The following table details the components of the Company's intangible assets: As of December 31, 2023 2022 (in thousands, except years) Weighted Average Remaining Amortization Period (in years) Cost Net of Accumulated Amortization Cost Net of Accumulated Amortization Customer relationships 0.0 $ 835 $ — $ 835 $ 226 Patents 11.1 1,600 520 1,490 456 Developed technology 19.1 8,307 7,379 607 165 Total $ 10,742 $ 7,899 $ 2,932 $ 847 Included in the Consolidated Statements of Operations is amortization expense related to intangible assets of $0.8 million and $0.5 million for the years ended December 31, 2023 and 2022, respectively. The estimated future amortization expense for existing intangible assets as of December 31, 2023 is expected to be approximately $0.4 million for the year ended December 31, 2024 and each of the four succeeding fiscal years. Investments The investments in entities in which the Company does not have a controlling interest (financial or operating), but where it has the ability to exercise significant influence over operating and financial policies, are accounted for using the equity method of accounting. Whether or not the Company exercises significant influence with respect to an investee depends on an evaluation of several factors including, among others, representation on the investee company’s board of directors and the Company's ownership percentage. Under the equity method of accounting, an investee company’s financial statements are not consolidated in the Company’s Consolidated Balance Sheets and Consolidated Statements of Operations; however, the Company’s share of the earnings or losses of the investee is reported in the "Earnings from equity method investments" line item in the Consolidated Statements of Operations, and the Company’s carrying value in an equity method investee is reported in the "Other long-term assets, net" line in the Consolidated Balance Sheets. The Company recognizes equity earnings from equity method investments based on its percentage ownership in the investee. The Company recognizes distributions received in excess of the carrying value of an equity method investment as equity method earnings in the period the distributions occur to the extent that the Company has not guaranteed any obligations of the investee or is not contractually required to provide additional funding to the investee. Subsequent earnings from investees where the Company has recognized earnings from distributions in excess of the carrying value of the equity method investment are recognized for the excess of cumulative earnings over previously recognized earnings from distributions. Additionally, when the Company's carrying value in an equity method investment is zero, and the Company has not guaranteed any obligations of the investee or is not required to provide additional funding to the investee, the Company will not recognize its share of any reported losses by the investee until future earnings are generated to offset previously unrecognized losses. Therefore, equity income (loss) reported in the Company's Consolidated Statements of Operations for certain equity method investees may differ from a mathematical calculation of net income or loss attributable to its equity interest based on the percentage ownership of the Company's equity interest and the net income or loss attributable to equity owners as shown in the investee's statements of operations. Distributions from equity method investees are reported in the Consolidated Statements of Cash Flows as "return on investment" in Operating cash flows until such time as the carrying value in an equity method investee is reduced to zero. Thereafter, such distributions are reported as "distributions in excess of cumulative earnings" in Investing cash flows. Investments in partially-owned subsidiaries for which the Company has less than 20% ownership are accounted for in accordance with accounting guidance applicable to equity investments that do not qualify for the equity method of accounting. The Company evaluates these types of investments for changes in fair value and, if there is change, recognizes the change in the Consolidated Statement of Operations. If no such events or changes in circumstances have occurred related to these types of investments, the fair value is estimated only if practicable to do so. Property, Plant and Equipment Property, plant and equipment are stated at cost less accumulated depreciation and include leasehold improvements. Depreciation on assets is computed using the straight-line method over the lesser of the estimated useful lives of the related assets or the lease term (ranging from 1 to 31 years). Maintenance and repairs that do not extend the useful life of the respective asset are charged to operating expenses as incurred. When assets are retired, or otherwise disposed of, the property accounts are relieved of costs and accumulated depreciation and any resulting gain or loss is credited or charged to income. The Company periodically evaluates the recoverability of the carrying value of property, plant and equipment for impairment. Amortization of right of use assets under finance lease is included in depreciation expense and is calculated using the straight-line method over the term of the lease. Leases The Company records a right of use ("ROU") asset and related liability under a contract or part of a contract when it conveys the right to control the use of an identified asset for a period of time in exchange for consideration. Control over the use of an identified asset occurs when an entity has both the right to obtain substantially all of the economic benefits from the use of an identified asset and the right to direct the use of that identified asset. The determination of whether a contract contains a lease may require significant assumptions and judgments. For all classes of underlying assets, the Company does not separate nonlease components from lease components and accounts for each separate lease component and the nonlease components associated with that lease component as a single lease component. The Company records lease liabilities and related ROU assets for all leases that have a term of greater than one year. For short-term leases (leases with terms of less than one year), the Company expenses lease payments on a straight-line basis over the lease term. Variable lease payments represent payments made by a lessee for the right to use an underlying asset that vary because of changes in facts or circumstances occurring after the commencement date of a lease other than the passage of time. Variable lease payments that are based on an index or rate, calculated by using the index or rate that exists on the lease commencement date, are included in the measurement of a lease liability. Certain of the Company’s operating leases for office facilities contain variable lease components that are not based on an index or rate, and the Company recognizes these payments as variable lease expense in the period in which the obligation for those payments is incurred. The Company calculates lease liabilities based on the present value of lease payments discounted by the rate implicit in the lease or, if not readily determinable, the Company’s incremental borrowing rate. Finance lease liabilities are subsequently measured by increasing the carrying amount to reflect interest expense on the finance lease liability and reducing the carrying amount of the lease liability to reflect lease payments made during the period. Interest on finance lease liabilities is determined in each period during the lease term as the amount that produces a constant periodic discount rate on the remaining balance of the lease liability. ROU assets under finance leases are amortized over the remaining lease term on a straight-line basis. Interest expense related to finance lease liabilities 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 Consolidated Statements of Operations. Operating lease liabilities are subsequently measured at the present value of the lease payments not yet paid, discounted using the discount rate for the lease established at the inception date of the lease. ROU assets under operating leases are subsequently measured at the amounts of the related operating lease liability, adjusted for, as applicable, prepaid or accrued lease payments, the remaining balance of any lease incentives received, unamortized initial direct costs and impairment. Lease expense from operating leases is recognized as a single lease cost over the remaining lease term on a straight-line basis. Variable lease payments not included in operating lease liabilities are recognized as expense in the period in which the obligation for those payments is incurred. Lease expense from operating leases is included in the "General and administrative" and "Consumables Cost of revenue, excluding depreciation and amortization" line items in the Consolidated Statements of Operations. Other Assets Mine Development Costs Mine development costs are related to the Five Forks Mine and are stated at cost less accumulated depletion and include acquisition costs, the cost of other development work and mitigation costs. Costs are amortized over the estimated life of the related mine reserves, which as of December 31, 2023 is estimated to be 14 years. 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. Mine development costs are reported in the "Other long-term assets, net" line item in the Consolidated Balance Sheets. Spare Parts 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 or capitalized in the period in which they are consumed or put into use. Spare parts are reported in the "Other long-term assets, net" line item in the Consolidated Balance Sheets. Revenue Recognition The Company recognizes revenue from a contract with a customer when a performance obligation under the terms of a contract with a customer is satisfied, which is when the customer controls the promised goods or services that are transferred in satisfaction of the performance obligation. Revenue is measured as the amount of consideration that is expected to be received in exchange for transferring goods or providing services, and the transaction price is generally fixed and generally does not contain variable or noncash consideration. In addition, the Company’s contracts with customers generally do not contain customer refund or return provisions or other similar obligations. Transfer of control and satisfaction of performance obligations are further discussed below. The Company uses estimates and judgments in determining the nature and timing of satisfaction of performance obligations, the standalone selling price ("SSP") of performance obligations and the allocation of the transaction price to multiple performance obligations, if any. The Company’s revenue component is Consumables. Consumables The Company is principally engaged in the sale of consumable products that utilize AC and chemical-based technologies to a broad range of customers, including coal-fired utilities, industrial and water treatment plants, and other diverse markets. The sale of consumable products is comprised of a single performance obligation and is recognized at the point in time when control transfers and the Company's obligation has been fulfilled, which is when the product is shipped or delivered to a customer. Performance obligations for the sale of consumable products do not extend beyond one year. Certain contracts with customers require the customers to purchase minimum quantities over the contractual period ("MQ Contracts"). Under these MQ Contracts, the Company reserves the right to bill a customer for any shortfall in the actual quantity purchases and minimum quantity purchases as of the end of the contractual period. The Company recognizes revenue on MQ Contracts based on the satisfaction of all three of the following criteria: (1) the likelihood of a customer not meeting its MQ contract obligations is probable, (2) the amount of the shortfall can be quantified and (3) the Company elects to exercise it right to enforce the billing of the shortfall at some point during the contractual period through a billing subsequent to the contractual period. The determination of when all three criteria are satisfied requires significant judgment. The Company performs shipping and handling activities through the use of third-party shippers and such activities occur prior to a customer obtaining control of goods. As such, the Company accounts for these activities as fulfillment activities and not as separate performance obligations. Shipping and handling costs incurred by the Company in delivering products to customers are billed to customers and are included in the transaction price and included in the "Revenue - Consumables" line item in the Consolidated Statements of Operations. Costs for shipping and handling activities incurred by the Company are included in the "Consumables cost of revenue, excluding depreciation and amortization" line item in the Consolidated Statements of Operations. Practical Expedients and Exemptions The Company does not disclose the value of unsatisfied performance obligations for contracts with an original expected length of one year or less. Sales and other taxes that are collected concurrently with revenue-producing activities are excluded from revenue. The Company generally expenses sales commissions when incurred, as the amortization period of the asset that the Company would have recognized is one year or less. These costs are recorded in sales and marketing expenses in the "General and administrative" line item in the Consolidated Statements of Operations. Consumables Cost of Revenue Consumables cost of revenue includes all labor, fringe benefits, subcontract labor, additive and coal costs, materials, equipment, supplies, travel costs and any other costs and expenses directly related to the Company’s production of revenue. License Royalties Payable to Tinuum Group In December 2022, the Company and Tinuum Group entered into an agreement (the "Tinuum Group Royalty Agreement") whereby the Company agreed to pay Tinuum Group a royalty (the "Tinuum Group Royalty") on sales of M-Prove TM to certain power plants where Tinuum Group had operated refined coal facilities (the "M-45 Facilities") prior to the expiration of the Section 45 Tax Credit Program on December 31, 2021. Amounts due under the Tinuum Group Royalty Agreement commenced on January 1, 2022. 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 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. The Tinuum Group Royalty is included in Cost of revenue in the Consolidated Statements of Operations. Payroll and Benefits Payroll and benefits costs include payroll costs, payroll related fringe benefits and stock based compensation expense of research and development, sales and administrative personnel, but exclude such costs related to direct labor that are included in Cost of revenue. Payroll and benefits costs include direct payroll, personnel related fringe benefits, sales and administrative staff labor costs and stock compensation expense. Payroll and benefits costs exclude direct labor included in Cost of revenue. Legal and Professional Legal and professional costs include external legal, audit and consulting expenses. General and Administrative General and administrative costs include director fees and expenses, rent, insurance and occupancy-related expenses, bad debt expense, impairments, research and development and other general costs of conducting business. Research and Development Research and development costs are charged to expense in the period incurred and are reported within the "Payroll and Benefits" and "General and administrative" line items in the Consolidated Statements of Operations. For the years ended December 31, 2023 and 2022, the Company recorded total research and development costs of $3.3 million and $2.1 million, respectively. Asset Retirement Obligations Asset retirement obligations ("ARO") are comprised of mine reclamation activities required under agreements related primarily to the Five Forks Mine and a coal waste site adjacent to the Corbin Facility (the "Corbin ARO") and are recognized when incurred and recorded as liabilities at fair value. An ARO is accreted over time through periodic charges to earnings. An ARO asset is depreciated over its estimated remaining life. Accounting for AROs requires the Company to estimate future costs unique to a specific mining operation that the Company expects to incur to complete the reclamation and remediation work required to comply with existing laws and regulations. AROs are periodically adjusted 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. On an annual basis, unless otherwise deemed necessary, the Company reviews its estimates and assumptions of its AROs. Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred income taxes are provided for temporary differences between the financial reporting basis and tax basis of the Company's assets and liabilities and are tax-effected using enacted tax rates in effect for the year in which the temporary differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in operations in the period that includes the enactment date. The Company maintains valuation allowances where it is more likely than not that all or a portion of deferred tax assets will not be realized. In making such a determination, the Company considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. The Company records uncertain tax positions on the basis of a two-step process whereby (1) the Company determines whether it is more-likely-than-not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, the Company recognizes the amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority. Stock-Based Compensation Stock-based compensation expense is measured at the grant date based on the estimated fair value of the stock-based award and is generally expensed on a straight-line basis over the requisite service period and/or performance period of the award. Forfeitures are recognized when incurred. Stock-based compensation expense related to manufacturing employees and administrative employees is included in the "Consumables Cost of revenue, exclusive of depreciation and amortization" and "Payroll and benefits" line items, respectively, in the Consolidated Statements of Operations. Stock-based compensation expense related to non-employee directors and consultants is included in the "General and administrative" line item in the Consolidated Statements of Operations. Dividends When a sufficient amount of available earnings exists at the time of a dividend declaration, dividends are charged to Retained earnings when declared. If a sufficient amount of available earnings is not available, dividends declared are charged as a reduction to Additional paid-in capital. 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 per share is computed in a manner consistent with that of basic earnings per share, while considering other potentially dilutive securities. The treasury stock method is used to determine the dilutive effect of potentially dilutive securities. Potentially dilutive securities consist of restricted stock awards ("RSAs") and contingent performance stock units ("PSUs") (collectively, "Potential dilutive shares"). Potential dilutive shares are excluded from diluted earnings (loss) per share when their effect is anti-dilutive. When there is a net loss for a period, all Potential dilutive shares are anti-dilutive and are excluded from the calculation of diluted loss per share for that period. Each PSU represents a contingent right to receive shares of the Company’s common stock, and the number of shares may range from zero to two times the number of PSUs granted on the award date depending upon the price performance of the Company's common stock as measured against a general index and a specific peer group index over requisite performance periods. The number of Potential dilutive shares related to a PSU is based on the number of shares of the Company's common stock, if any, that would be issuable at the end of the respective reporting period, assuming that the end of the reporting period is the end of the contingency period applicable to a PSU. See Note 12 for additional information related to PSUs. The following table sets forth the calculations of basic and diluted earnings (loss) per common share: Years Ended December 31, (in thousands, except per share amounts) 2023 2022 Net loss $ (12,249) $ (8,917) Basic weighted-average number of common shares outstanding 29,104 18,453 Add: dilutive effect of equity instruments — — Diluted weighted-average shares outstanding 29,104 18,453 Loss per share - basic $ (0.42) $ (0.48) Loss per share - diluted $ (0.42) $ (0.48) For the years ended December 31, 2023 and 2022, 1.7 million and 0.6 million weighted-average equity instruments, respectively, were outstanding but were not included in the computation of diluted earnings per share because their effect would have been anti-dilutive. Use of Estimates The preparation of the Company’s consolidated financial statements in conformity with accounting principles generally accepted in the United States ("GAAP") requires the Company’s management to make estimates and assumptions that affect the amounts reported in these financial statements and accompanying notes. Actual results could differ from those estimates. Significant financial statement components in which the Company makes assumptions include: • business combinations, including asset acquisitions; • the carrying value of its long-lived assets; • AROs; and • income taxes, including the valuation allowance for deferred tax assets and assessment of uncertain tax positions. Risks and Uncertainties The Company is principally dependent on operations of its APT business and its cash on hand to provide liquidity over the near and long term. The Company's revenue, 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 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 generally an increase in coal consumption and thus demand for the Company's products also increases. In addition, coal consumption 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 operating results are subject to seasonal variations whereby its revenue and cost of revenue 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. Reclassifications Certain balances have been reclassified from prior years 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. Segments Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by a company's chief operating decision maker ("CODM"), or a decision-making group, in deciding how to allocate resources and in assessing financial performance. As of December 31, 2023, the Company's CODM was the Company's Chief Executive Officer, and the Company concluded that it had one reportable segment. New Accounting Standards Recently Adopted 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. Recently Issued In December 2023, the FASB issued Accounting Standards Update 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures |