Fuel Tech (FTEK) 10-Q 13 Nov 19 2019 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Oct. 31, 2019
Document and Entity Information [Abstract]
Entity Registrant Name	FUEL TECH, INC.
Document Type	10-Q
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		24,186,824
Amendment Flag	false
Entity Central Index Key	0000846913
Entity Filer Category	Non-accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Shell Company	false
Entity Current Reporting Status	Yes
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus (Q1,Q2,Q3,FY)	Q3

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 12,850,000	$ 12,039,000
Restricted cash	988,000	6,020,000
Accounts receivable, net of allowance for doubtful accounts of $1,175 and $1,411, respectively	10,124,000	18,399,000
Inventories, net	291,000	957,000
Prepaid expenses and other current assets	1,834,000	3,184,000
Income taxes receivable	130,000	118,000
Total current assets	26,217,000	40,717,000
Property and equipment, net of accumulated depreciation of $25,993 and $26,528, respectively	5,712,000	5,976,000
Goodwill	2,116,000	2,116,000
Other intangible assets, net of accumulated amortization of $6,611 and $6,608, respectively	966,000	1,164,000
Restricted cash	1,494,000	0
Right-of-use operating lease assets	1,104,000	0
Assets held for sale		485,000
Other assets	270,000	1,261,000
Total assets	37,879,000	51,719,000
Current liabilities:
Accounts payable	2,618,000	9,499,000
Accrued liabilities:
Operating lease liabilities - current	376,000	0
Employee compensation	661,000	1,563,000
Other accrued liabilities	2,419,000	6,099,000
Total current liabilities	6,074,000	17,161,000
Operating lease liabilities - non-current	715,000	0
Deferred income taxes	171,000	171,000
Other liabilities	278,000	335,000
Total liabilities	7,238,000	17,667,000
COMMITMENTS AND CONTINGENCIES (Note 14)
Stockholders’ equity:
Common stock, $.01 par value, 40,000,000 shares authorized, 24,843,668 and 24,825,891 shares issued, and 24,186,824 and 24,170,585 shares outstanding, respectively	248,000	248,000
Additional paid-in capital	139,349,000	138,992,000
Accumulated deficit	(105,985,000)	(102,495,000)
Accumulated other comprehensive loss	(1,561,000)	(1,285,000)
Nil coupon perpetual loan notes	76,000	76,000
Treasury stock, at cost	(1,486,000)	(1,484,000)
Total stockholders’ equity	30,641,000	34,052,000
Total liabilities and stockholders’ equity	$ 37,879,000	$ 51,719,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Revenues	$ 6,452	$ 16,070	$ 25,555	$ 40,708
Costs and expenses:
Cost of sales	3,563	10,654	14,754	26,545
Selling, general and administrative	3,822	4,105	12,735	13,789
Restructuring charge	0	0	625	0
Research and development	352	265	823	814
Intangible assets abandonment	76	0	127	317
Costs and expenses:	7,813	15,024	29,064	41,465
Operating income (loss) from continuing operations	(1,361)	1,046	(3,509)	(757)
Interest expense	(4)	0	(8)	0
Interest income	19	1	30	3
Other expense	71	8	(1)	(59)
Income (loss) from continuing operations before income taxes	(1,275)	1,055	(3,488)	(813)
Income tax expense	(21)	0	(23)	(2)
Net income (loss) from continuing operations	(1,296)	1,055	(3,511)	(815)
Income (loss) from discontinued operations (net of income tax benefit of $0 in 2019 and 2018)	18	(10)	(1)	(109)
Net income (loss)	$ (1,278)	$ 1,045	$ (3,512)	$ (924)
Basic
Continuing operations (in dollars per share)	$ (0.05)	$ 0.04	$ (0.15)	$ (0.04)
Discontinued operations (in dollars per share)	0	0	0	0
Basic net loss per common share (in dollars per share)	(0.05)	0.04	(0.15)	(0.04)
Diluted
Continuing operations (in dollars per share)	(0.05)	0.04	(0.15)	(0.04)
Discontinued operations (in dollars per share)	0	0	0	0
Diluted net loss per common share (in dollars per share)	$ (0.05)	$ 0.04	$ (0.15)	$ (0.04)
Weighted-average number of common shares outstanding:
Basic (in shares)	24,187,000	24,171,000	24,183,000	24,162,000
Diluted (in shares)	24,187,000	24,588,000	24,183,000	24,162,000

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Operations (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Income tax benefit	$ 0	$ 0	$ 0	$ 0

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 1,175	$ 1,411
Accumulated depreciation	25,993	26,528
Accumulated amortization	$ 6,611	$ 6,608
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	40,000,000	40,000,000
Common stock, shares issued (in shares)	24,843,668	24,825,891
Common stock outstanding (in shares)	24,186,824	24,170,585

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (1,278)	$ 1,045	$ (3,512)	$ (924)
Other comprehensive income (loss):
Foreign currency translation adjustments	(337)	(263)	(276)	(441)
Unrealized losses from marketable securities, net of tax	0	0	0	(3)
Total other comprehensive income (loss)	(337)	(263)	(276)	(444)
Comprehensive income (loss)	$ (1,615)	$ 782	$ (3,788)	$ (1,368)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders’ Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Total accumulated other comprehensive loss	Nil Coupon Perpetual Loan Notes	Treasury Stock
Balance (in shares) at Dec. 31, 2017		24,133
Balance at beginning of period at Dec. 31, 2017	$ 34,172	$ 248	$ 138,760	$ (102,672)	$ (768)	$ 76	$ (1,472)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(216)			(216)
Foreign currency translation adjustments	416				416
Unrealized losses from marketable securities, net of tax	(1)				(1)
Stock compensation expense	(59)		(59)
Common shares issued upon vesting of restricted stock units (in shares)		45
Treasury shares withheld (in shares)		(10)
Treasury shares withheld	(10)						(10)
Adoption of ASC	205			205
Balance (in shares) at Mar. 31, 2018		24,168
Balance at end of period at Mar. 31, 2018	34,507	$ 248	138,701	(102,683)	(353)	76	(1,482)
Balance (in shares) at Dec. 31, 2017		24,133
Balance at beginning of period at Dec. 31, 2017	34,172	$ 248	138,760	(102,672)	(768)	76	(1,472)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(924)
Foreign currency translation adjustments	(441)
Unrealized losses from marketable securities, net of tax	(3)
Balance (in shares) at Sep. 30, 2018		24,170
Balance at end of period at Sep. 30, 2018	33,131	$ 248	138,894	(103,391)	(1,212)	76	(1,484)
Balance (in shares) at Mar. 31, 2018		24,168
Balance at beginning of period at Mar. 31, 2018	34,507	$ 248	138,701	(102,683)	(353)	76	(1,482)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(1,753)			(1,753)
Foreign currency translation adjustments	(594)				(594)
Unrealized losses from marketable securities, net of tax	(2)				(2)
Stock compensation expense	97		97
Common shares issued upon vesting of restricted stock units (in shares)		4
Common shares issued upon vesting of restricted stock units	(1)		(1)
Treasury shares withheld (in shares)		(2)
Treasury shares withheld	(2)						(2)
Balance (in shares) at Jun. 30, 2018		24,170
Balance at end of period at Jun. 30, 2018	32,252	$ 248	138,797	(104,436)	(949)	76	(1,484)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	1,045			1,045
Foreign currency translation adjustments	(263)				(263)
Unrealized losses from marketable securities, net of tax	0				0
Stock compensation expense	97		97
Balance (in shares) at Sep. 30, 2018		24,170
Balance at end of period at Sep. 30, 2018	33,131	$ 248	138,894	(103,391)	(1,212)	76	(1,484)
Balance (in shares) at Dec. 31, 2018		24,170
Balance at beginning of period at Dec. 31, 2018	34,052	$ 248	138,992	(102,495)	(1,285)	76	(1,484)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(1,289)			(1,289)
Foreign currency translation adjustments	104				104
Stock compensation expense	96		96
Common shares issued upon vesting of restricted stock units (in shares)		18
Common shares issued upon vesting of restricted stock units	0
Treasury shares withheld (in shares)		(2)
Treasury shares withheld	(2)						(2)
Adoption of ASC	22			22
Balance (in shares) at Mar. 31, 2019		24,186
Balance at end of period at Mar. 31, 2019	32,983	$ 248	139,088	(103,762)	(1,181)	76	(1,486)
Balance (in shares) at Dec. 31, 2018		24,170
Balance at beginning of period at Dec. 31, 2018	34,052	$ 248	138,992	(102,495)	(1,285)	76	(1,484)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(3,512)
Foreign currency translation adjustments	(276)
Unrealized losses from marketable securities, net of tax	0
Balance (in shares) at Sep. 30, 2019		24,186
Balance at end of period at Sep. 30, 2019	30,641	$ 248	139,349	(105,985)	(1,561)	76	(1,486)
Balance (in shares) at Mar. 31, 2019		24,186
Balance at beginning of period at Mar. 31, 2019	32,983	$ 248	139,088	(103,762)	(1,181)	76	(1,486)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(945)			(945)
Foreign currency translation adjustments	(43)				(43)
Stock compensation expense	123		123
Balance (in shares) at Jun. 30, 2019		24,186
Balance at end of period at Jun. 30, 2019	32,118	$ 248	139,211	(104,707)	(1,224)	76	(1,486)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(1,278)			(1,278)
Foreign currency translation adjustments	(337)				(337)
Unrealized losses from marketable securities, net of tax	0
Stock compensation expense	138		138
Balance (in shares) at Sep. 30, 2019		24,186
Balance at end of period at Sep. 30, 2019	$ 30,641	$ 248	$ 139,349	$ (105,985)	$ (1,561)	$ 76	$ (1,486)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating Activities
Net income (loss)	$ (3,512,000)	$ (924,000)
Loss from discontinued operations	1,000	109,000
Net income (loss) from continuing operations	(3,511,000)	(815,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	644,000	502,000
Amortization	118,000	158,000
Loss (gain) on disposal of equipment	4,000	(11,000)
Provision for doubtful accounts, net of recoveries	0	(62,000)
Intangible assets abandonment	127,000	317,000
Stock-based compensation, net of forfeitures	357,000	135,000
Changes in operating assets and liabilities:
Accounts receivable	8,601,000	(7,192,000)
Inventories	654,000	280,000
Prepaid expenses, other current assets and other non-current assets	1,804,000	1,840,000
Accounts payable	(6,812,000)	3,896,000
Accrued liabilities and other non-current liabilities	(4,306,000)	(1,378,000)
Net cash used in operating activities - continuing operations	(2,320,000)	(2,330,000)
Net cash used in operating activities - discontinued operations	(21,000)	(334,000)
Net cash used in operating activities	(2,341,000)	(2,664,000)
Investing Activities
Purchases of equipment and patents	(431,000)	(392,000)
Proceeds from the sale of equipment	0	1,000
Net cash used in investing activities - continuing operations	(431,000)	(391,000)
Net cash provided by investing activities - discontinued operations (Note 4)	505,000	0
Net cash used in investing activities - continuing operations	74,000	(391,000)
Financing Activities
Taxes paid on behalf of equity award participants	(2,000)	(12,000)
Net cash used in financing activities	(2,000)	(12,000)
Effect of exchange rate fluctuations on cash	(458,000)	(601,000)
Net decrease in cash, cash equivalents and restricted cash	(2,727,000)	(3,668,000)
Cash, cash equivalents, and restricted cash at beginning of period (Note 2)	18,059,000	14,386,000
Cash, cash equivalents and restricted cash at end of period (Note 2)	$ 15,332,000	$ 10,718,000

General

General	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	General Organization Fuel Tech, Inc. and subsidiaries ("Fuel Tech", the "Company", "we", "us" or "our") provides advanced engineered solutions for the optimization of combustion systems in utility and industrial applications. Our primary focus is on the worldwide marketing and sale of NO x reduction technologies as well as our FUEL CHEM program. The Company’s NO x reduction technologies reduce nitrogen oxide emissions from boilers, furnaces and other stationary combustion sources. Our FUEL CHEM program is based on proprietary TIFI ® Targeted In-Furnace™ Injection technology, in combination with advanced Computational Fluid Dynamics (CFD) and Chemical Kinetics Modeling (CKM) boiler modeling, in the unique application of specialty chemicals to improve the efficiency, reliability and environmental status of combustion units by controlling slagging, fouling, corrosion, opacity and other sulfur trioxide-related issues in the boiler. Our business is materially dependent on the continued existence and enforcement of air quality regulations, particularly in the United States. We have expended significant resources in the research and development of new technologies in building our proprietary portfolio of air pollution control, fuel and boiler treatment chemicals, computer modeling and advanced visualization technologies. Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X of the Exchange Act. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, the financial statements reflect all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation of the statements for the periods presented. All significant intercompany transactions and balances have been eliminated. The results of operations for the three and nine months ended September 30, 2019 are not necessarily indicative of the results to be expected for the full year ending December 31, 2019. For further information, refer to the audited consolidated financial statements and footnotes thereto included in Fuel Tech’s Annual Report on Form 10-K for the year ended December 31, 2018 as filed with the Securities and Exchange Commission.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Restricted cash Restricted cash as of September 30, 2019 represents funds that are restricted to satisfy any amount borrowed against the Company's Cash Collateral Security agreement with BMO Harris Bank N.A. The balance of restricted cash totaling $2,482 is comprised of $988 in current assets relating to existing standby letters of credit with varying maturity dates and expire no later than September 30, 2020 and $1,494 in long-term assets will remain through the expiration dates of the underlying standby letter of credits (the latest maturity date is February 1, 2023) with BMO Harris Bank N.A. Refer to Note 10 Debt Financing for further information on the Cash Collateral Security agreement with BMO Harris Bank N.A. The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the Consolidated Balance Sheet that sum to the total of the same such amounts shown in the Consolidated Statements of Cash Flows: September 30, December 31, Cash and cash equivalents $ 12,850 $ 12,039 Restricted cash included in current assets 988 6,020 Restricted cash included in long-term assets 1,494 — Total cash, cash equivalents, and restricted cash shown in the Consolidated Statements of Cash Flows $ 15,332 $ 18,059 Leases On January 1, 2019, we adopted ASC 842 using the modified retrospective method outlined in ASU 2018-11, “Leases (Topic 842) Targeted Improvements.” Refer to Note 12 for further details regarding the effect of adoption. We determine if an arrangement is a lease at inception. Operating leases are included in right-of-use ("ROU") operating lease assets, operating lease liabilities - current, and operating lease liabilities - non-current on our Consolidated Balance Sheets. Operating lease ROU assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of future payments. The operating lease ROU asset also includes any lease payments made and excludes lease incentives and initial direct costs incurred. Our lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. We have lease agreements with lease and non-lease components, which we elected the practical expedient to not separate lease and non-lease components for the majority of our leases. For certain equipment leases, such as vehicles, we account for the lease and non-lease components as a single lease component. We also elected the practical expedient to keep leases with an initial term of 12 months or less off of the consolidated balance sheet.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenue	Revenue The Company recognizes revenue when control of the promised goods or services is transferred to our customers, in amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. Fuel Tech’s sales of products to customers represent single performance obligations. The majority of our contracts have a single performance obligation as the promise to transfer the individual goods or services is not separately identifiable from other promises in the contracts and, therefore, not distinct. Revenue is measured as the amount of consideration we expect to receive in exchange for transferring goods or providing services. Sales, value add, and other taxes we collect concurrent with revenue-producing activities are excluded from revenue. We generally expense sales commissions on a ratable basis when incurred because the amortization period would have been one year or less. These costs are recorded within selling, general and administrative expenses within the Condensed Consolidated Statements of Operations. FUEL CHEM Revenues from the sale of chemical products are recognized when control transfers to customer upon shipment or delivery of the product based on the applicable shipping terms. We generally recognize revenue for these arrangements at a point in time based on our evaluation of when the customer obtains control of the promised goods or services. Air Pollution Control Technology Fuel Tech’s APC contracts are typically six to eighteen months in length. A typical contract will have three or four critical operational measurements that, when achieved, serve as the basis for us to invoice the customer via progress billings. At a minimum, these measurements will include the generation of engineering drawings, the shipment of equipment and the completion of a system performance test. As part of most of its contractual APC project agreements, Fuel Tech will agree to customer-specific acceptance criteria that relate to the operational performance of the system that is being sold. These criteria are determined based on modeling that is performed by Fuel Tech personnel, which is based on operational inputs that are provided by the customer. The customer will warrant that these operational inputs are accurate as they are specified in the binding contractual agreement. Further, the customer is solely responsible for the accuracy of the operating condition information; typically all performance guarantees and equipment warranties granted by us are voidable if the operating condition information is inaccurate or is not met. Since control transfers over time, revenue is recognized based on the extent of progress towards completion of the single performance obligation. Fuel Tech uses the cost-to-cost input measure of progress for our contracts since it best depicts the transfer of assets to the customer which occurs as we incur costs on our contracts. Under the cost-to-cost input measure of progress, the extent of progress towards completion is measured based on the ratio of costs incurred to date to the total estimated costs at completion of the performance obligation. Revenues are recorded proportionally as costs are incurred. Costs to fulfill include all internal and external engineering costs, equipment charges, inbound and outbound freight expenses, internal and site transfer costs, installation charges, purchasing and receiving costs, inspection costs, warehousing costs, project personnel travel expenses and other direct and indirect expenses specifically identified as project- or product-line related, as appropriate (e.g. test equipment depreciation and certain insurance expenses). Fuel Tech has installed over 1,000 units with APC technology and normally provides performance guarantees to our customers based on the operating conditions for the project. As part of the project implementation process, we perform system start-up and optimization services that effectively serve as a test of actual project performance. We believe that this test, combined with the accuracy of the modeling that is performed, enables revenue to be recognized prior to the receipt of formal customer acceptance. Disaggregated Revenue by Product Technology The following table presents our revenues disaggregated by product technology: Three Months Ended Nine Months Ended 2019 2018 2019 2018 Air Pollution Control Technology solutions $ 1,191 $ 10,202 $ 9,727 $ 25,516 Spare parts 299 334 832 863 Ancillary revenue 326 346 1,849 1,493 Total Air Pollution Control Technology revenues 1,816 10,882 12,408 27,872 FUEL CHEM FUEL CHEM technology solutions 4,636 5,188 13,147 12,836 Total Revenues $ 6,452 $ 16,070 $ 25,555 $ 40,708 Disaggregated Revenue by Geography The following table presents our revenues disaggregated by geography, based on the billing addresses of our customers: Three Months Ended Nine Months Ended 2019 2018 2019 2018 United States $ 5,727 $ 11,629 $ 22,104 $ 30,701 Foreign Revenues South America 282 278 474 904 Europe 283 1,907 1,568 4,935 Asia 160 2,256 1,409 4,168 Total Foreign Revenues 725 4,441 3,451 10,007 Total Revenues $ 6,452 $ 16,070 $ 25,555 $ 40,708 Timing of Revenue Recognition The following table presents the timing of our revenue recognition: Three Months Ended Nine Months Ended 2019 2018 2019 2018 Products transferred at a point in time $ 5,261 $ 5,868 $ 15,828 $ 15,192 Products and services transferred over time 1,191 10,202 9,727 25,516 Total Revenues $ 6,452 $ 16,070 $ 25,555 $ 40,708 Contract Balances The timing of revenue recognition, billings and cash collections results in billed accounts receivable, unbilled receivables (contract assets), and customer advances and deposits (contract liabilities) on the consolidated balance sheets. In our Air Pollution Control Technology segment, amounts are billed as work progresses in accordance with agreed-upon contractual terms. Generally, billing occurs subsequent to revenue recognition, resulting in contract assets. These assets are reported on the consolidated balance sheet on a contract-by-contract basis at the end of each reporting period. At September 30, 2019 and December 31, 2018 , contract assets were approximately $1,589 and $5,540 , respectively, and are included in accounts receivable on the consolidated balance sheets. However, the Company will periodically bill in advance of costs incurred before revenue is recognized, resulting in contract liabilities. These liabilities are reported on the consolidated balance sheet on a contract-by-contract basis at the end of each reporting period. Contract liabilities were $682 and $1,234 , at September 30, 2019 and December 31, 2018 , respectively, and are included in other accrued liabilities on the consolidated balance sheets. Changes in the contract asset and liability balances during the nine month period ended September 30, 2019 , were not materially impacted by any other items other than amounts billed and revenue recognized as described previously. Revenue recognized that was included in the contract liability balance at the beginning of the period was $302 and $1,059 for the three and nine months ended September 30, 2019 and $7 and $2,165 for three and nine months ended September 30, 2018 , respectively, which represented primarily revenue from progress towards completion of our Air Pollution Control technology contracts. As of September 30, 2019 , we had six construction contracts in progress that were identified as loss contracts and a provision for losses of $74 was recorded in other accrued liabilities on the consolidated balance sheet. Refer to Footnote 14 for an accrual related to certain non-conformance issues with a U.S. customer associated with equipment that requires remedy under the warranty provision of the customer contract. As of December 31, 2018 , we had five construction contracts in progress that were identified as loss contracts and a provision for losses in the amount of $123 was recorded in other accrued liabilities on the consolidated balance sheet. Remaining Performance Obligations Remaining performance obligations, represents the transaction price of Air Pollution Control technology booked orders for which work has not been performed. As of September 30, 2019 , the aggregate amount of the transaction price allocated to remaining performance obligations was $6,773 . The Company expects to recognize revenue on approximately $5,150 of the remaining performance obligations over the next 12 months with the remaining recognized thereafter. Accounts Receivable The components of accounts receivable are as follows: As of September 30, 2019 December 31, 2018 Trade receivables $ 7,563 $ 14,261 Unbilled receivables 1,589 5,540 Insurance proceeds receivable (Note 14) 1,991 — Other short-term receivables 156 9 Allowance for doubtful accounts (1,175 ) (1,411 ) Total accounts receivable $ 10,124 $ 18,399

Discontinued Operations

Discontinued Operations	9 Months Ended
	Sep. 30, 2019
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Discontinued Operations During the second quarter of 2017, the Company suspended all operations associated with the Fuel Conversion business segment. The components of the net assets of the Fuel Conversion discontinued operations are Assets held for sale (which consists primarily of certain equipment) on the Consolidated Balance Sheets totaling $0 and $485 as of September 30, 2019 and December 31, 2018 , respectively. The Company sold the remaining Fuel Conversion equipment within Assets held for sale during the nine month period ended September 30, 2019 for sales proceeds net of selling costs of $505 , resulting in a gain on sale of $20 recorded in discontinued operations. Following the sale of the remaining Fuel Conversion equipment during the third quarter, the Company completed the wind-down activities associated with the Fuel Conversion business segment. In addition, accrued severance of $0 and $65 is included in the other accrued liabilities line of the Consolidated Balance Sheets as of September 30, 2019 and December 31, 2018 , respectively. A total of $5 and $65 was paid during the three and nine months ended September 30, 2019 . The Fuel Conversion business segment had no other assets or liabilities associated with it. The activity of the Fuel Conversion discontinued operations consisted primarily of storage costs for holding the equipment at a third-party location totaling $2 and $21 for the three and nine months ended September 30, 2019 and the gain on sale of $20 recorded in discontinued operations during the third quarter. The activity for the Fuel Conversion discontinued operations consisted of Research and Development, severance and other costs for the three and nine months ended September 30, 2018 of $10 and $109 , respectively. The Fuel Conversion business segment had no revenues associated with it.

Restructuring Activities

Restructuring Activities	9 Months Ended
	Sep. 30, 2019
Restructuring and Related Activities [Abstract]
Restructuring Activities	Restructuring Activities On January 18, 2019, the Company announced a planned suspension of its Air Pollution Control (“APC”) business operation in China. This action is part of Fuel Tech’s ongoing operational improvement initiatives designed to prioritize resource allocation, reduce costs, and drive profitability for the Company on a global basis. The transition associated with the suspension of the APC business which has taken place through September 30, 2019 includes staff rationalization and reduction, supplier and partner engagement, and the monetization of certain assets. The remaining transition activities include the execution of the remaining activities to satisfy the requirements for the remaining APC projects in China (with a backlog totaling approximately $47 ) in addition to collection efforts for the remaining accounts receivable. The following table presents our revenues and net loss (which includes the Restructuring charge line item within the Condensed Statements of Operations) in China as follows: Three Months Ended Nine Months Ended 2019 2018 2019 2018 Total revenues $ — $ 1,066 $ 311 $ 2,406 Net loss (80 ) (435 ) (1,469 ) (1,588 ) Total assets primarily consist of cash, accounts receivable, contract assets, prepaid expenses and other current assets. Total liabilities consist of accounts payable and certain accrued liabilities. The following table presents net assets in China as follows: As of September 30, 2019 December 31, 2018 Total assets $ 4,308 $ 8,546 Total liabilities (266 ) (2,953 ) Total net assets $ 4,042 $ 5,593 The Company incurred approximately $562 of severance costs relating to the suspension of the APC business in China, of which $90 and $562 were paid during the three and nine months ended September 30, 2019 . On January 23, 2019, the Company notified the landlord of our intention to early terminate the lease on July 22, 2019. The Company incurred an early termination penalty of $63 during the first quarter of 2019, which is included in restructuring expense for the nine months ended September 30, 2019 . The Company recorded restructuring charges of $0 and $625 for the three and nine months ended September 30, 2019 and $0 and $0 in 2018, respectively. The charge consisted primarily of one-time severance costs of $562 and the early termination penalty for our lease associated with the suspension of our APC business in China of $63 . The following is a reconciliation of the accrual for the workforce reduction that is included within the "Accrued Liabilities - Employee Compensation" line of the consolidated balance sheets for the three and nine months ending September 30, 2019 and 2018 : Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Restructuring liability at beginning of period $ 155 $ 188 $ 65 $ 391 Amounts expensed — — 625 — Amounts paid (155 ) (93 ) (690 ) (296 ) Restructuring liability at end of period $ — $ 95 $ — $ 95 The restructuring liability for the three and nine months ended September 30, 2018 relates to severance costs associated with the suspension of the Fuel Conversion business segment.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	9 Months Ended
	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss The changes in accumulated other comprehensive loss by component were as follows: Three months ended September 30, Nine Months Ended 2019 2018 2019 2018 Foreign currency translation Balance at beginning of period $ (1,224 ) $ (950 ) $ (1,285 ) $ (772 ) Other comprehensive loss: Foreign currency translation adjustments (1) (337 ) (263 ) (276 ) (441 ) Balance at end of period $ (1,561 ) $ (1,213 ) $ (1,561 ) $ (1,213 ) Available-for-sale marketable securities Balance at beginning of period $ — $ 1 $ — $ 4 Other comprehensive income: Net unrealized holding loss (2) — — — (3 ) Balance at end of period $ — $ 1 $ — $ 1 Total accumulated other comprehensive loss $ (1,561 ) $ (1,212 ) $ (1,561 ) $ (1,212 ) (1) In all periods presented, there were no tax impacts related to rate changes and no amounts were reclassified to earnings. (2) In all periods presented, there were no realized holding gains or losses and therefore no amounts were reclassified to earnings.

Treasury Stock

Treasury Stock	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Treasury Stock	Treasury Stock Common stock held in treasury totaled 656,844 and 655,306 with a cost of $1,486 and $1,484 at September 30, 2019 and December 31, 2018 , respectively. These shares were withheld from employees to settle personal tax withholding obligations that arose as a result of restricted stock units that vested in the periods presented.

Earnings per Share

Earnings per Share	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Earnings per Share	Earnings per Share Basic earnings per share excludes the dilutive effects of stock options, restricted stock units (RSUs), and the nil coupon non-redeemable convertible unsecured loan notes. Diluted earnings per share includes the dilutive effect of the nil coupon non-redeemable convertible unsecured loan notes, RSUs, and unexercised in-the-money stock options, except in periods of net loss where the effect of these instruments is anti-dilutive. Out-of-money stock options are excluded from diluted earnings per share because they are anti-dilutive. For the three and nine months ended September 30, 2019 and for the nine months ended September 30, 2018 , basic earnings per share is equal to diluted earnings per share because all outstanding stock awards and convertible loan notes are considered anti-dilutive during periods of net loss. For the three months ended September 30, 2018, diluted earnings per share includes unexercised options and unvested RSUs since net income was generated in that period and the effect of those instruments is dilutive. The following table sets forth the weighted-average shares used in calculating the earnings per share for the three and nine months ended September 30, 2019 and 2018 . Three Months Ended Nine Months Ended 2019 2018 2019 2018 Basic weighted-average shares 24,187,000 24,171,000 24,183,000 24,162,000 Conversion of unsecured loan notes — — — — Unexercised options and unvested RSUs — 417,000 — — Diluted weighted-average shares 24,187,000 24,588,000 24,183,000 24,162,000 Fuel Tech had 1,269,000 and 1,286,000 weighted average equity awards outstanding at September 30, 2019 and 2018 , respectively, that were not dilutive for the purposes of inclusion in the calculation of diluted earnings per share but could potentially become dilutive in future periods.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2019
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation Under our stock-based employee compensation plan, referred to as the Fuel Tech, Inc. 2014 Long-Term Incentive Plan (Incentive Plan), awards may be granted to participants in the form of Non-Qualified Stock Options, Incentive Stock Options, Stock Appreciation Rights, Restricted Stock, Restricted Stock Units (“RSUs”), Performance Awards, Bonuses or other forms of share-based or non-share-based awards or combinations thereof. Participants in the Incentive Plan may be our directors, officers, employees, consultants or advisors (except consultants or advisors in capital-raising transactions) as the directors determine are key to the success of our business. There are a maximum of 5,600,676 shares that may be issued or reserved for awards to participants under the Incentive Plan. As of September 30, 2019 , Fuel Tech had 2,092,136 shares available for share-based awards under the 2014 Plan. We did not record any excess tax benefits within income tax expense for the three and nine months ended September 30, 2019 . Given the Company has a full valuation allowance on its deferred tax assets, there were no excess tax benefits to record for the three and nine months ended September 30, 2019 . In addition, we account for forfeitures of awards based on an estimate of the number of awards expected to be forfeited and adjusting the estimate when it is no longer probable that the employee will fulfill the service condition. Stock-based compensation is included in selling, general, and administrative costs in our Consolidated Statements of Operations. The components of stock-based compensation for the three and nine months ended September 30, 2019 and 2018 were as follows: Three Months Ended Nine Months Ended September 30, 2019 2018 2019 2018 Stock options and restricted stock units, net of forfeited $ 138 $ 97 $ 357 $ 135 Tax benefit of stock-based compensation expense — — — — After-tax effect of stock-based compensation $ 138 $ 97 $ 357 $ 135 Stock Options Stock options granted to employees under the Incentive Plans have a 10 -year life and they vest as follows: 50% after the second anniversary of the award date, 25% after the third anniversary, and the final 25% after the fourth anniversary of the award date. Fuel Tech calculates stock compensation expense for employee option awards based on the grant date fair value of the award, less expected annual forfeitures, and recognizes expense on a straight-line basis over the four -year service period of the award. Stock options granted to members of our board of directors vest immediately. Stock compensation for these awards is based on the grant date fair value of the award and is recognized in expense immediately. Fuel Tech uses the Black-Scholes option pricing model to estimate the grant date fair value of employee stock options. The principal variable assumptions utilized in valuing options and the methodology for estimating such model inputs include: (1) risk-free interest rate – an estimate based on the yield of zero–coupon treasury securities with a maturity equal to the expected life of the option; (2) expected volatility – an estimate based on the historical volatility of Fuel Tech’s Common Stock for a period equal to the expected life of the option; and (3) expected life of the option – an estimate based on historical experience including the effect of employee terminations. Stock option activity for Fuel Tech’s Incentive Plans for the nine months ended September 30, 2019 was as follows: Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding on January 1, 2019 932,500 $ 4.68 Granted — — Exercised — — Expired or forfeited (185,000 ) 10.14 Outstanding on September 30, 2019 747,500 $ 3.33 4.98 $ 4 Exercisable on September 30, 2019 747,500 $ 3.33 4.98 $ 4 As of September 30, 2019 , there was no unrecognized compensation cost related to non-vested stock options granted under the Incentive Plans. Restricted Stock Units Restricted stock units (RSUs) granted to employees vest over time based on continued service (typically vesting over a period between two and four years). Such time-vested RSUs are valued at the date of grant using the intrinsic value method based on the closing price of the Common Shares on the grant date. Compensation cost, adjusted for estimated forfeitures, is amortized on a straight-line basis over the requisite service period. In addition to the time vested RSUs, the Company entered into a 2019 Executive Performance RSU Award Agreement (the “2019 Agreement”) with certain officers, including its President and Chief Executive Officer and Principal Financial Officer and Controller pursuant to which each 2019 Participating Executive will have the opportunity to earn a specified amount of restricted stock units (RSUs). The amount of RSUs awarded, if any, will be based on the Company’s achievement of varying levels of operating income before the impact of incentive pay (but including adjustments to reflect the payment of sales commissions) in fiscal 2019 (“Operating Income”), as determined by the Company, in its sole discretion. Nevertheless, no Participating Executive will be entitled to any such RSUs unless the Company achieves a minimum of $2 million in Operating Income in 2019. If awarded, such RSUs will vest in equal amounts ( i.e., 1/3, 1/3 and 1/3) over three years commencing one year after the grant date based on continued service. Such RSUs are valued at the date of grant using the intrinsic value method based on the closing price of the Company’s common stock on the grant date. At September 30, 2019 , there is $489 of unrecognized compensation cost related to all non-vested share-based compensation arrangements granted under the Incentive Plan. That cost is expected to be recognized over the remaining requisite service period of 1.56 years. A summary of restricted stock unit activity for the nine months ended September 30, 2019 is as follows: Shares Weighted Average Grant Date Fair Value Unvested restricted stock units at January 1, 2019 1,110,277 $ 1.21 Granted 228,135 1.52 Forfeited — — Vested (17,777 ) 1.59 Unvested restricted stock units at September 30, 2019 1,320,635 $ 1.26 The fair value of restricted stock that vested during the nine month period ending September 30, 2019 was $22 . Deferred Directors Fees In addition to the Incentive Plans, Fuel Tech has a Deferred Compensation Plans for Directors (Deferred Plan). Under the terms of the Deferred Plan, Directors can elect to defer Directors’ fees for shares of Fuel Tech Common Stock that are issuable at a future date as defined in the agreement. In accordance with ASC 718, Fuel Tech accounts for these awards as equity awards as opposed to liability awards. During the nine month periods ended September 30, 2019 and 2018 , Fuel Tech recorded no stock-based compensation expense under the Deferred Plan.

Debt Financing

Debt Financing	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Debt Financing	Debt Financing On June 19, 2019, the Company entered into a Cash Collateral Security agreement with BMO Harris Bank, N.A. (the BMO Harris agreement) to use for the sole purpose of issuing standby letters of credit. The BMO Harris agreement requires us to pledge as cash collateral 105% of the aggregate face amount of outstanding standby letters of credit. The Company pays 250 basis points on the face values of outstanding letters of credit. There are no financial covenants set forth in the BMO Harris agreement. At September 30, 2019 , the Company had outstanding standby letters of credit totaling approximately $2,361 under the BMO Harris agreement. As of September 30, 2019 , the Company held $2,482 in a separate restricted use designated BMO Harris Bank N.A. deposit account. Fuel Tech is committed to reimbursing the issuing bank for any payments made by the bank under these instruments. In connection with the transition to BMO Harris Bank N.A., the Company canceled its U.S. Domestic credit facility with JPMorgan Chase Bank, N.A. effective on September 25, 2019.

Business Segment and Geographic

Business Segment and Geographic Financial Data	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Business Segment and Geographic Financial Data	Business Segment and Geographic Financial Data Business Segment Financial Data We segregate our financial results into two reportable segments representing two broad technology segments as follows: • The Air Pollution Control technology segment includes technologies to reduce NO x emissions in flue gas from boilers, incinerators, furnaces and other stationary combustion sources. These include Low and Ultra Low NO x Burners (LNB and ULNB), Over-Fire Air (OFA) systems, NO x OUT ® and HERT™ Selective Non-Catalytic Reduction (SNCR) systems, and Advanced Selective Catalytic Reduction (ASCR ™ ) systems. Our ASCR systems include ULNB, OFA, and SNCR components, along with a downsized SCR catalyst, Ammonia Injection Grid (AIG), and Graduated Straightening Grid GSG™ systems to provide high NO x reductions at significantly lower capital and operating costs than conventional SCR systems. The NO x OUT CASCADE ® and NO x OUT-SCR ® processes are more basic, using just SNCR and SCR catalyst components. ULTRA™ technology creates ammonia at a plant site using safe urea for use with any SCR application. Flue Gas Conditioning systems are chemical injection systems offered in markets outside the U.S. and Canada to enhance electrostatic precipitator and fabric filter performance in controlling particulate emissions. • The FUEL CHEM ® technology segment, which uses chemical processes in combination with advanced CFD and CKM boiler modeling, for the control of slagging, fouling, corrosion, opacity and other sulfur trioxide-related issues in furnaces and boilers through the addition of chemicals into the furnace using TIFI ® Targeted In-Furnace Injection™ technology. The “Other” classification includes those profit and loss items not allocated to either reportable segment. There are no inter-segment sales that require elimination. We evaluate performance and allocate resources based on reviewing gross margin by reportable segment. The accounting policies of the reportable segments are the same as those described in the summary of significant accounting policies (Note 1 in our annual report on Form 10-K). We do not review assets by reportable segment, but rather, in aggregate for the Company as a whole. Information about reporting segment net sales and gross margin from continuing operations are provided below: Three months ended September 30, 2019 Air Pollution FUEL CHEM Other Total Revenues from external customers $ 1,816 $ 4,636 $ — $ 6,452 Cost of sales (1,197 ) (2,366 ) — (3,563 ) Gross margin 619 2,270 — 2,889 Selling, general and administrative — — (3,822 ) (3,822 ) Research and development — — (352 ) (352 ) Intangible assets abandonment — — (76 ) (76 ) Operating income (loss) from continuing operations $ 619 $ 2,270 $ (4,250 ) $ (1,361 ) ` Three months ended September 30, 2018 Air Pollution FUEL CHEM Other Total Revenues from external customers $ 10,882 $ 5,188 $ — $ 16,070 Cost of sales (8,116 ) (2,538 ) — (10,654 ) Gross margin 2,766 2,650 — 5,416 Selling, general and administrative — — (4,105 ) (4,105 ) Research and development — — (265 ) (265 ) Operating income (loss) from continuing operations $ 2,766 $ 2,650 $ (4,370 ) $ 1,046 Nine months ended September 30, 2019 Air Pollution FUEL CHEM Other Total Revenues from external customers $ 12,408 $ 13,147 $ — $ 25,555 Cost of sales (8,061 ) (6,693 ) — (14,754 ) Gross margin 4,347 6,454 — 10,801 Selling, general and administrative — — (12,735 ) (12,735 ) Restructuring charge — — (625 ) (625 ) Research and development — — (823 ) (823 ) Intangible assets abandonment (127 ) (127 ) Operating income (loss) from continuing operations $ 4,347 $ 6,454 $ (14,310 ) $ (3,509 ) Nine months ended September 30, 2018 Air Pollution FUEL CHEM Other Total Revenues from external customers $ 27,872 $ 12,836 $ — $ 40,708 Cost of sales (20,040 ) (6,505 ) — (26,545 ) Gross margin 7,832 6,331 — 14,163 Selling, general and administrative — — (13,789 ) (13,789 ) Research and development — — (814 ) (814 ) Intangible assets abandonment — — (317 ) (317 ) Operating income (loss) from continuing operations $ 7,832 $ 6,331 $ (14,920 ) $ (757 ) Geographic Segment Financial Data Information concerning our operations by geographic area is provided below. Revenues are attributed to countries based on the location of the customer. Assets are those directly associated with operations of the geographic area. Three Months Ended Nine Months Ended September 30, 2019 2018 2019 2018 Revenues: United States 5,727 11,629 22,104 30,701 Foreign 725 4,441 3,451 10,007 6,452 16,070 25,555 40,708 September 30, December 31, Assets: United States $ 29,437 $ 36,784 Foreign 8,442 14,935 $ 37,879 $ 51,719

Leases

Leases	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Leases	Leases Adoption of ASC 842, "Leases" On January 1, 2019, we adopted ASC 842 using the modified retrospective method outlined in ASU 2018-11 "Leases (Topic 842) Targeted Improvements." Results for reporting periods beginning after January 1, 2019 are presented under ASC 842, while prior period amounts are not adjusted and continue to be reported in accordance with our legacy accounting under Accounting Standards Codification Topic 840: Leases (ASC 840). The Company recorded the transition to ASC 842 by recognizing a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption rather than in the earliest period presented. We have elected the package of practical expedients permitted under the transition guidance, which among other things, allow us to carry forward the historical accounting relating to lease identification and classification for existing leases upon adoption. We have also elected the practical expedient to not separate lease and non-lease components for the majority of our leases and the election to keep leases with an initial term of 12 months or less off of the consolidated balance sheet. The cumulative effect of the changes made to our January 1, 2019 consolidated balance sheet for the adoption of ASC 842 were as follows: Balance at December 31, 2018 Adjustments Upon Adoption of ASC 842 Balance at January 1, 2019 Assets Right-of-use operating lease assets $ — $ 1,592 $ 1,592 Liabilities Other accrued liabilities 6,099 (22 ) 6,077 Operating lease liabilities - current — 650 650 Operating lease liabilities - non-current — 942 942 Equity Accumulated deficit (102,495 ) 22 (102,473 ) The adjustment made to the January 1, 2019 consolidated balance sheet related to an accrued liability for lease escalation clauses in certain of our leases under ASC 840 which is a cumulative-effect adjustment to the opening balance of accumulated deficit upon the adoption of ASC 842. Leases We have nine total operating leases which relate to both office space locations and certain office equipment. Our leases have remaining lease terms of 1 year to 6 years. Our leases do not contain any material residual value guarantees or material restricted covenants and we currently have no material sublease arrangements. We have no financing leases as defined under ASC 842. Total operating lease expense for the three and nine months ended September 30, 2019 is as follows: For the Three Months ended September 30, 2019 For the Nine Months ended September 30, 2019 Operating lease cost $ 171 $ 514 Short-term lease cost 1 135 Total lease cost $ 172 $ 649 The weighted average remaining lease term was 4.33 years as of September 30, 2019 . The weighted average discount rate was 3.52% as of September 30, 2019 . Remaining maturities of our existing lease liabilities as of September 30, 2019 were as follows: Year Ending December 31, Operating Leases 2019 (excluding the nine months ended September 30, 2019) $ 160 2020 310 2021 218 2022 165 2023 152 Thereafter 196 Total lease payments $ 1,201 Less imputed interest (110 ) Total $ 1,091 The following is the balance sheet classification of our existing lease liabilities as of September 30, 2019 : Operating lease liabilities - current $ 376 Operating lease liabilities - non-current 715 Total operating lease liabilities $ 1,091 Supplemental cash flow information related to leases was as follows: For the Three Months ended September 30, 2019 For the Nine Months ended September 30, 2019 Cash paid for amounts included in the measurement of lease liabilities $ 162 $ 505 Leased assets obtained in exchange for operating lease liabilities 154 482

Accrued Liabilities

Accrued Liabilities	9 Months Ended
	Sep. 30, 2019
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued Liabilities The components of other accrued liabilities are as follows: As of September 30, 2019 December 31, 2018 Contract liabilities (Note 3) $ 682 $ 1,234 Accrued remediation contingency (Note 14) 760 — Other accrued liabilities 977 4,865 Total other accrued liabilities $ 2,419 $ 6,099

Contingencies

Contingencies	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies Fuel Tech is subject to various claims and contingencies related to, among other things, workers compensation, general liability (including product liability), and lawsuits. The Company records liabilities where a contingent loss is probable and can be reasonably estimated. If the reasonable estimate of a probable loss is a range, the Company records the most probable estimate of the loss or the minimum amount when no amount within the range is a better estimate than any other amount. The Company discloses a contingent liability even if the liability is not probable or the amount is not estimable, or both, if there is a reasonable possibility that a material loss may have been incurred. From time to time we are involved in litigation with respect to matters arising from the ordinary conduct of our business. In the opinion of management, based upon presently available information, either adequate provision for anticipated costs have been accrued or the ultimate anticipated costs will not materially affect our consolidated financial position, results of operations, or cash flows. We do not believe we have any pending loss contingencies that are probable or reasonably possible of having a material impact on our consolidated financial position, results of operations or cash flows. During the fourth quarter of 2018, the Company was notified of certain non-conformance issues with a U.S. customer associated with equipment that requires remedy under the warranty provision of the contract. The Company is in the process of remedying the non-conformance issues. During the first quarter of 2019, the Company filed a notice of claim with our insurance carrier and received a confirmation of insurance coverage. As a result, the company recorded $973 as expected insurance proceeds from our insurance carrier and $1,223 (including the insurance policy deductible of $250 ) as an accrued liability associated with the remedy of the non-conformance issues identified with our customer for the three months ended March 31, 2019. During the second quarter of 2019, we revised our claim estimate with our insurance carrier and recorded an additional $1,005 as expected insurance proceeds from our insurance carrier and an additional $1,005 as an accrued liability associated with the completion of the non-conformance issues for the three months ended June 30, 2019. As of September 30, 2019 , we have total receivables from the insurance carrier of $1,991 in the accounts receivable line of the Consolidated Balance Sheets and a total accrued liability associated with the completion of the non-conformance issues of $760 in the other accrued liabilities line of the Consolidated Balance Sheets. The Company recorded the amount due from our insurance carrier as our insurance coverage and the terms are not in dispute and the claim submitted is consistent with the terms of insurance coverage provided. The Company currently has $500 of accounts receivable which is past due associated with this project. Upon satisfactory completion of non-conformance issues identified with the customer, the Company expects to collect the remaining accounts receivable due from the customer. Fuel Tech issues a standard product warranty with the sale of its products to customers. Our recognition of warranty liability is based primarily on analyses of warranty claims experienced in the preceding years as the nature of our historical product sales for which we offer a warranty are substantially unchanged. This approach provides an aggregate warranty accrual that is historically aligned with actual warranty claims experienced. There was no change in the warranty liability balance during the nine months ended September 30, 2019 and 2018 . The warranty liability balance was $159 at September 30, 2019 and 2018 .

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company’s effective tax rate is approximately 0% for the three and nine month periods ended September 30, 2019 and 2018 , respectively. The Company's effective tax rate differs from the statutory federal tax rate of 21% for the three and nine month periods ended September 30, 2019 primarily due to a full valuation allowance recorded on our United States, China and Italy deferred tax assets since we cannot anticipate when or if we will have sufficient taxable income to utilize the deferred tax assets in the future. Further, our effective tax rate differs from the statutory federal tax rate due to state taxes, differences between U.S. and foreign tax rates, foreign losses incurred with no related tax benefit, non-deductible commissions, and non-deductible meals and entertainment expenses for the three and nine month periods ended September 30, 2019 and 2018 . On April 3, 2019, the Company received notice from the Internal Revenue Service that our U.S. income tax return for the year ended December 31, 2016 is currently under audit. Fuel Tech had no unrecognized tax benefits as of September 30, 2019 and December 31, 2018 .

Goodwill and Other Intangibles

Goodwill and Other Intangibles	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangibles	Goodwill and Other Intangibles Goodwill is allocated among and evaluated for impairment at the reporting unit level, which is defined as an operating segment or one level below an operating segment. Fuel Tech has two reporting units for goodwill evaluation purposes: the FUEL CHEM ® technology segment and the APC technology segment. There is no goodwill associated with our APC segment. At both September 30, 2019 and December 31, 2018 , our entire goodwill balance of $2,116 was allocated to the FUEL CHEM ® technology segment. Goodwill is allocated to each of our reporting units after considering the nature of the net assets giving rise to the goodwill and how each reporting unit would enjoy the benefits and synergies of the net assets acquired. There were no indications of goodwill impairment in the nine months ended September 30, 2019 and 2018 . Fuel Tech reviews other intangible assets, which include customer lists and relationships, covenants not to compete, patent assets, tradenames, and acquired technologies, for impairment on a recurring basis or when events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. In the event that impairment indicators exist, a further analysis is performed and if the sum of the expected undiscounted future cash flows resulting from the use of the asset is less than the carrying amount of the asset, an impairment loss equal to the excess of the asset’s carrying value over its fair value is recorded. Management considers historical experience and all available information at the time the estimates of future cash flows are made, however, the actual cash values that could be realized may differ from those that are estimated. During the third quarter of 2019, the Company recorded an abandonment charge of $76 principally associated with the remaining patent assets in China which the Company elected to not maintain and abandon as a result of the planned suspension of the APC business operation in China. The abandonment charge was calculated by determining the net book values of the abandoned patent assets by deducting the accumulated amortization from the acquisition cost. The abandonment charge is included in “Intangible assets abandonment” line in the accompanying Condensed Statements of Operations for the three and nine months ended September 30, 2019 . There were no indications of intangible asset impairments for the nine month period ended September 30, 2019 .

General (Policies)

General (Policies)	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X of the Exchange Act. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, the financial statements reflect all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation of the statements for the periods presented. All significant intercompany transactions and balances have been eliminated. The results of operations for the three and nine months ended September 30, 2019 are not necessarily indicative of the results to be expected for the full year ending December 31, 2019. For further information, refer to the audited consolidated financial statements and footnotes thereto included in Fuel Tech’s Annual Report on Form 10-K for the year ended December 31, 2018 as filed with the Securities and Exchange Commission.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
New Accounting Pronouncements	Leases On January 1, 2019, we adopted ASC 842 using the modified retrospective method outlined in ASU 2018-11, “Leases (Topic 842) Targeted Improvements.” Refer to Note 12 for further details regarding the effect of adoption. We determine if an arrangement is a lease at inception. Operating leases are included in right-of-use ("ROU") operating lease assets, operating lease liabilities - current, and operating lease liabilities - non-current on our Consolidated Balance Sheets. Operating lease ROU assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of future payments. The operating lease ROU asset also includes any lease payments made and excludes lease incentives and initial direct costs incurred. Our lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. We have lease agreements with lease and non-lease components, which we elected the practical expedient to not separate lease and non-lease components for the majority of our leases. For certain equipment leases, such as vehicles, we account for the lease and non-lease components as a single lease component. We also elected the practical expedient to keep leases with an initial term of 12 months or less off of the consolidated balance sheet.
Revenue Recognition	The Company recognizes revenue when control of the promised goods or services is transferred to our customers, in amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. Fuel Tech’s sales of products to customers represent single performance obligations. The majority of our contracts have a single performance obligation as the promise to transfer the individual goods or services is not separately identifiable from other promises in the contracts and, therefore, not distinct. Revenue is measured as the amount of consideration we expect to receive in exchange for transferring goods or providing services. Sales, value add, and other taxes we collect concurrent with revenue-producing activities are excluded from revenue. We generally expense sales commissions on a ratable basis when incurred because the amortization period would have been one year or less. These costs are recorded within selling, general and administrative expenses within the Condensed Consolidated Statements of Operations. FUEL CHEM Revenues from the sale of chemical products are recognized when control transfers to customer upon shipment or delivery of the product based on the applicable shipping terms. We generally recognize revenue for these arrangements at a point in time based on our evaluation of when the customer obtains control of the promised goods or services. Air Pollution Control Technology Fuel Tech’s APC contracts are typically six to eighteen months in length. A typical contract will have three or four critical operational measurements that, when achieved, serve as the basis for us to invoice the customer via progress billings. At a minimum, these measurements will include the generation of engineering drawings, the shipment of equipment and the completion of a system performance test. As part of most of its contractual APC project agreements, Fuel Tech will agree to customer-specific acceptance criteria that relate to the operational performance of the system that is being sold. These criteria are determined based on modeling that is performed by Fuel Tech personnel, which is based on operational inputs that are provided by the customer. The customer will warrant that these operational inputs are accurate as they are specified in the binding contractual agreement. Further, the customer is solely responsible for the accuracy of the operating condition information; typically all performance guarantees and equipment warranties granted by us are voidable if the operating condition information is inaccurate or is not met. Since control transfers over time, revenue is recognized based on the extent of progress towards completion of the single performance obligation. Fuel Tech uses the cost-to-cost input measure of progress for our contracts since it best depicts the transfer of assets to the customer which occurs as we incur costs on our contracts. Under the cost-to-cost input measure of progress, the extent of progress towards completion is measured based on the ratio of costs incurred to date to the total estimated costs at completion of the performance obligation. Revenues are recorded proportionally as costs are incurred. Costs to fulfill include all internal and external engineering costs, equipment charges, inbound and outbound freight expenses, internal and site transfer costs, installation charges, purchasing and receiving costs, inspection costs, warehousing costs, project personnel travel expenses and other direct and indirect expenses specifically identified as project- or product-line related, as appropriate (e.g. test equipment depreciation and certain insurance expenses). Fuel Tech has installed over 1,000 units with APC technology and normally provides performance guarantees to our customers based on the operating conditions for the project. As part of the project implementation process, we perform system start-up and optimization services that effectively serve as a test of actual project performance. We believe that this test, combined with the accuracy of the modeling that is performed, enables revenue to be recognized prior to the receipt of formal customer acceptance.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Schedule of Cash, Cash Equivalents, and Restricted Cash	The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the Consolidated Balance Sheet that sum to the total of the same such amounts shown in the Consolidated Statements of Cash Flows: September 30, December 31, Cash and cash equivalents $ 12,850 $ 12,039 Restricted cash included in current assets 988 6,020 Restricted cash included in long-term assets 1,494 — Total cash, cash equivalents, and restricted cash shown in the Consolidated Statements of Cash Flows $ 15,332 $ 18,059

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table presents the timing of our revenue recognition: Three Months Ended Nine Months Ended 2019 2018 2019 2018 Products transferred at a point in time $ 5,261 $ 5,868 $ 15,828 $ 15,192 Products and services transferred over time 1,191 10,202 9,727 25,516 Total Revenues $ 6,452 $ 16,070 $ 25,555 $ 40,708 The following table presents our revenues disaggregated by product technology: Three Months Ended Nine Months Ended 2019 2018 2019 2018 Air Pollution Control Technology solutions $ 1,191 $ 10,202 $ 9,727 $ 25,516 Spare parts 299 334 832 863 Ancillary revenue 326 346 1,849 1,493 Total Air Pollution Control Technology revenues 1,816 10,882 12,408 27,872 FUEL CHEM FUEL CHEM technology solutions 4,636 5,188 13,147 12,836 Total Revenues $ 6,452 $ 16,070 $ 25,555 $ 40,708
Revenue Disaggregated by Geography	The following table presents our revenues disaggregated by geography, based on the billing addresses of our customers: Three Months Ended Nine Months Ended 2019 2018 2019 2018 United States $ 5,727 $ 11,629 $ 22,104 $ 30,701 Foreign Revenues South America 282 278 474 904 Europe 283 1,907 1,568 4,935 Asia 160 2,256 1,409 4,168 Total Foreign Revenues 725 4,441 3,451 10,007 Total Revenues $ 6,452 $ 16,070 $ 25,555 $ 40,708
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]	The components of accounts receivable are as follows: As of September 30, 2019 December 31, 2018 Trade receivables $ 7,563 $ 14,261 Unbilled receivables 1,589 5,540 Insurance proceeds receivable (Note 14) 1,991 — Other short-term receivables 156 9 Allowance for doubtful accounts (1,175 ) (1,411 ) Total accounts receivable $ 10,124 $ 18,399

Restructuring Activities (Table

Restructuring Activities (Tables)	9 Months Ended
	Sep. 30, 2019
Restructuring and Related Activities [Abstract]
Restructuring	The following table presents our revenues and net loss (which includes the Restructuring charge line item within the Condensed Statements of Operations) in China as follows: Three Months Ended Nine Months Ended 2019 2018 2019 2018 Total revenues $ — $ 1,066 $ 311 $ 2,406 Net loss (80 ) (435 ) (1,469 ) (1,588 ) The following table presents net assets in China as follows: As of September 30, 2019 December 31, 2018 Total assets $ 4,308 $ 8,546 Total liabilities (266 ) (2,953 ) Total net assets $ 4,042 $ 5,593
Reconciliation of restructuring accrual	The following is a reconciliation of the accrual for the workforce reduction that is included within the "Accrued Liabilities - Employee Compensation" line of the consolidated balance sheets for the three and nine months ending September 30, 2019 and 2018 : Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Restructuring liability at beginning of period $ 155 $ 188 $ 65 $ 391 Amounts expensed — — 625 — Amounts paid (155 ) (93 ) (690 ) (296 ) Restructuring liability at end of period $ — $ 95 $ — $ 95 The restructuring liability for the three and nine months ended September 30, 2018 relates to severance costs associated with the suspension of the Fuel Conversion business segment.

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	9 Months Ended
	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The changes in accumulated other comprehensive loss by component were as follows: Three months ended September 30, Nine Months Ended 2019 2018 2019 2018 Foreign currency translation Balance at beginning of period $ (1,224 ) $ (950 ) $ (1,285 ) $ (772 ) Other comprehensive loss: Foreign currency translation adjustments (1) (337 ) (263 ) (276 ) (441 ) Balance at end of period $ (1,561 ) $ (1,213 ) $ (1,561 ) $ (1,213 ) Available-for-sale marketable securities Balance at beginning of period $ — $ 1 $ — $ 4 Other comprehensive income: Net unrealized holding loss (2) — — — (3 ) Balance at end of period $ — $ 1 $ — $ 1 Total accumulated other comprehensive loss $ (1,561 ) $ (1,212 ) $ (1,561 ) $ (1,212 ) (1) In all periods presented, there were no tax impacts related to rate changes and no amounts were reclassified to earnings. (2) In all periods presented, there were no realized holding gains or losses and therefore no amounts were reclassified to earnings.

Earnings per Share (Tables)

Earnings per Share (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table sets forth the weighted-average shares used in calculating the earnings per share for the three and nine months ended September 30, 2019 and 2018 . Three Months Ended Nine Months Ended 2019 2018 2019 2018 Basic weighted-average shares 24,187,000 24,171,000 24,183,000 24,162,000 Conversion of unsecured loan notes — — — — Unexercised options and unvested RSUs — 417,000 — — Diluted weighted-average shares 24,187,000 24,588,000 24,183,000 24,162,000

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2019
Share-based Payment Arrangement [Abstract]
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs	The components of stock-based compensation for the three and nine months ended September 30, 2019 and 2018 were as follows: Three Months Ended Nine Months Ended September 30, 2019 2018 2019 2018 Stock options and restricted stock units, net of forfeited $ 138 $ 97 $ 357 $ 135 Tax benefit of stock-based compensation expense — — — — After-tax effect of stock-based compensation $ 138 $ 97 $ 357 $ 135
Schedule of Stock Option Activity	Stock option activity for Fuel Tech’s Incentive Plans for the nine months ended September 30, 2019 was as follows: Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding on January 1, 2019 932,500 $ 4.68 Granted — — Exercised — — Expired or forfeited (185,000 ) 10.14 Outstanding on September 30, 2019 747,500 $ 3.33 4.98 $ 4 Exercisable on September 30, 2019 747,500 $ 3.33 4.98 $ 4
Schedule of Nonvested Restricted Stock Units Activity	A summary of restricted stock unit activity for the nine months ended September 30, 2019 is as follows: Shares Weighted Average Grant Date Fair Value Unvested restricted stock units at January 1, 2019 1,110,277 $ 1.21 Granted 228,135 1.52 Forfeited — — Vested (17,777 ) 1.59 Unvested restricted stock units at September 30, 2019 1,320,635 $ 1.26

Business Segment and Geograph_2

Business Segment and Geographic Financial Data (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Information about reporting segment net sales and gross margin from continuing operations are provided below: Three months ended September 30, 2019 Air Pollution FUEL CHEM Other Total Revenues from external customers $ 1,816 $ 4,636 $ — $ 6,452 Cost of sales (1,197 ) (2,366 ) — (3,563 ) Gross margin 619 2,270 — 2,889 Selling, general and administrative — — (3,822 ) (3,822 ) Research and development — — (352 ) (352 ) Intangible assets abandonment — — (76 ) (76 ) Operating income (loss) from continuing operations $ 619 $ 2,270 $ (4,250 ) $ (1,361 ) ` Three months ended September 30, 2018 Air Pollution FUEL CHEM Other Total Revenues from external customers $ 10,882 $ 5,188 $ — $ 16,070 Cost of sales (8,116 ) (2,538 ) — (10,654 ) Gross margin 2,766 2,650 — 5,416 Selling, general and administrative — — (4,105 ) (4,105 ) Research and development — — (265 ) (265 ) Operating income (loss) from continuing operations $ 2,766 $ 2,650 $ (4,370 ) $ 1,046
Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area	Information concerning our operations by geographic area is provided below. Revenues are attributed to countries based on the location of the customer. Assets are those directly associated with operations of the geographic area. Three Months Ended Nine Months Ended September 30, 2019 2018 2019 2018 Revenues: United States 5,727 11,629 22,104 30,701 Foreign 725 4,441 3,451 10,007 6,452 16,070 25,555 40,708
Schedule of Disclosure on Geographic Areas, Long-Lived Assets in Individual Foreign Countries by Country	September 30, December 31, Assets: United States $ 29,437 $ 36,784 Foreign 8,442 14,935 $ 37,879 $ 51,719

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Schedule of Cumulative Effect of Changes to Balance Sheet	The cumulative effect of the changes made to our January 1, 2019 consolidated balance sheet for the adoption of ASC 842 were as follows: Balance at December 31, 2018 Adjustments Upon Adoption of ASC 842 Balance at January 1, 2019 Assets Right-of-use operating lease assets $ — $ 1,592 $ 1,592 Liabilities Other accrued liabilities 6,099 (22 ) 6,077 Operating lease liabilities - current — 650 650 Operating lease liabilities - non-current — 942 942 Equity Accumulated deficit (102,495 ) 22 (102,473 )
Schedule of Lease Costs	Total operating lease expense for the three and nine months ended September 30, 2019 is as follows: For the Three Months ended September 30, 2019 For the Nine Months ended September 30, 2019 Operating lease cost $ 171 $ 514 Short-term lease cost 1 135 Total lease cost $ 172 $ 649 Supplemental cash flow information related to leases was as follows: For the Three Months ended September 30, 2019 For the Nine Months ended September 30, 2019 Cash paid for amounts included in the measurement of lease liabilities $ 162 $ 505 Leased assets obtained in exchange for operating lease liabilities 154 482 Supplemental cash flow information related to leases was as follows: For the Three Months ended September 30, 2019 For the Nine Months ended September 30, 2019 Cash paid for amounts included in the measurement of lease liabilities $ 162 $ 505 Leased assets obtained in exchange for operating lease liabilities 154 482
Lessee, Operating Lease, Liability, Maturity	Remaining maturities of our existing lease liabilities as of September 30, 2019 were as follows: Year Ending December 31, Operating Leases 2019 (excluding the nine months ended September 30, 2019) $ 160 2020 310 2021 218 2022 165 2023 152 Thereafter 196 Total lease payments $ 1,201 Less imputed interest (110 ) Total $ 1,091
Assets And Liabilities, Lessee	The following is the balance sheet classification of our existing lease liabilities as of September 30, 2019 : Operating lease liabilities - current $ 376 Operating lease liabilities - non-current 715 Total operating lease liabilities $ 1,091

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	9 Months Ended
	Sep. 30, 2019
Payables and Accruals [Abstract]
Schedule of other accrued liabilities	The components of other accrued liabilities are as follows: As of September 30, 2019 December 31, 2018 Contract liabilities (Note 3) $ 682 $ 1,234 Accrued remediation contingency (Note 14) 760 — Other accrued liabilities 977 4,865 Total other accrued liabilities $ 2,419 $ 6,099

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Restricted Cash and Cash Equivalents Items [Line Items]
Balance of total restricted cash	$ 2,482
Cash and cash equivalents	12,850	$ 12,039
Restricted cash included in current assets	988	6,020
Restricted cash included in long-term assets	1,494	0
Total cash, cash equivalents, and restricted cash shown in the Consolidated Statements of Cash Flows	15,332	$ 18,059	$ 10,718	$ 14,386
Restricted Until Maturity Date
Restricted Cash and Cash Equivalents Items [Line Items]
Balance of total restricted cash	988
Restricted Until Expiration of Agreement December 2020
Restricted Cash and Cash Equivalents Items [Line Items]
Balance of total restricted cash	$ 1,494

Revenue - Additional Informatio

Revenue - Additional Information (Details) unit in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)contract	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)unitcontract	Sep. 30, 2018USD ($)	Dec. 31, 2018USD ($)contract
Revenue from Contract with Customer [Abstract]
Number of units installed (over) | unit			1
Unbilled receivables, current	$ 1,589		$ 1,589		$ 5,540
Billings in excess of cost, current	682		682		$ 1,234
Revenue recognized, included in contract liability balance	$ 302	$ 7	$ 1,059	$ 2,165
Number of contracts identified as loss contracts | contract	6		6		5
Provision for losses on contracts	$ 74		$ 74		$ 123

Revenue - Revenues Disaggregate

Revenue - Revenues Disaggregated by Product Technology (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Total Revenues	$ 6,452	$ 16,070	$ 25,555	$ 40,708
Air Pollution Control
Disaggregation of Revenue [Line Items]
Total Revenues	1,816	10,882	12,408	27,872
Air Pollution Control | Technology solutions
Disaggregation of Revenue [Line Items]
Total Revenues	1,191	10,202	9,727	25,516
Air Pollution Control | Spare parts
Disaggregation of Revenue [Line Items]
Total Revenues	299	334	832	863
Air Pollution Control | Ancillary revenue
Disaggregation of Revenue [Line Items]
Total Revenues	326	346	1,849	1,493
FUEL CHEM
Disaggregation of Revenue [Line Items]
Total Revenues	4,636	5,188	13,147	12,836
FUEL CHEM | Technology solutions
Disaggregation of Revenue [Line Items]
Total Revenues	$ 4,636	$ 5,188	$ 13,147	$ 12,836

Revenue - Disaggregated Revenue

Revenue - Disaggregated Revenue by Geography (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Total Revenues	$ 6,452	$ 16,070	$ 25,555	$ 40,708
United States
Disaggregation of Revenue [Line Items]
Total Revenues	5,727	11,629	22,104	30,701
South America
Disaggregation of Revenue [Line Items]
Total Revenues	282	278	474	904
Europe
Disaggregation of Revenue [Line Items]
Total Revenues	283	1,907	1,568	4,935
Asia
Disaggregation of Revenue [Line Items]
Total Revenues	160	2,256	1,409	4,168
Total Foreign Revenues
Disaggregation of Revenue [Line Items]
Total Revenues	$ 725	$ 4,441	$ 3,451	$ 10,007

Revenue - Timing of Revenue Rec

Revenue - Timing of Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Total Revenues	$ 6,452	$ 16,070	$ 25,555	$ 40,708
Products transferred at a point in time
Disaggregation of Revenue [Line Items]
Total Revenues	5,261	5,868	15,828	15,192
Products and services transferred over time
Disaggregation of Revenue [Line Items]
Total Revenues	$ 1,191	$ 10,202	$ 9,727	$ 25,516

Revenue - Remaining Performance

Revenue - Remaining Performance Obligations (Details) $ in Thousands	Sep. 30, 2019USD ($)
Revenue from Contract with Customer [Abstract]
Remaining performance obligations	$ 6,773
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligations	$ 5,150
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, period	1 year

Revenue - Components of Account

Revenue - Components of Accounts Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Trade receivables	$ 7,563	$ 14,261
Unbilled receivables	1,589	5,540
Insurance proceeds receivable (Note 14)	1,991	0
Other short-term receivables	156	9
Allowance for doubtful accounts	(1,175)	(1,411)
Total accounts receivable	$ 10,124	$ 18,399

Discontinued Operations (Detail

Discontinued Operations (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale					$ 485,000
Storage costs	$ 1,000		$ 135,000
Fuel Conversion Segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Severance costs	5,000		65,000
Research and Development, severance and other costs		$ 10,000		$ 109,000
Revenue			0
Fuel Conversion Segment | Accrued Liabilities
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Accrued severance charges	0		0		65,000
Sold | Fuel Conversion Segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal consideration					505,000
Gain on sale			20,000
Storage costs	2,000		21,000
Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale	$ 0		$ 0		$ 485,000

Restructuring Activities - Char

Restructuring Activities - Charges and Net Assets (Details) - USD ($) $ in Thousands	Jan. 23, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Total Revenues		$ 6,452			$ 16,070			$ 25,555	$ 40,708
Net income (loss)		(1,278)	$ (945)	$ (1,289)	1,045	$ (1,753)	$ (216)	(3,512)	(924)
Total assets		37,879						37,879		$ 51,719
Liabilities		(7,238)						(7,238)		(17,667)
Payments for restructuring		155			93			690	296
Restructuring charge		0			0			625	0
CHINA
Restructuring Cost and Reserve [Line Items]
Remaining performance requirements for APC projects		47						47
Total Revenues		0			1,066			311	2,406
Net income (loss)		(80)			$ (435)			(1,469)	$ (1,588)
Total assets		4,308						4,308		8,546
Liabilities		(266)						(266)		(2,953)
Total net assets		4,042						4,042		$ 5,593
CHINA | Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring, expected cost		562						562
Payments for restructuring		$ 90						562
Restructuring charge								562
CHINA | Facility Closing
Restructuring Cost and Reserve [Line Items]
Restructuring charge	$ 63							$ 63

Restructuring Activities - Rese

Restructuring Activities - Reserve (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Restructuring Reserve [Roll Forward]
Restructuring liability, beginning balance	$ 155	$ 188	$ 65	$ 391
Amounts expensed	0	0	625	0
Amounts paid	(155)	(93)	(690)	(296)
Restructuring liability, ending balance	$ 0	$ 95	$ 0	$ 95

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]
Balance at beginning of period	$ 32,118	$ 32,252	$ 34,052	$ 34,172
Balance at end of period	30,641	33,131	30,641	33,131
Foreign currency translation
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]
Balance at beginning of period	(1,224)	(950)	(1,285)	(772)
Total other comprehensive (loss) income	(337)	(263)	(276)	(441)
Balance at end of period	(1,561)	(1,213)	(1,561)	(1,213)
Available-for-sale marketable securities
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]
Balance at beginning of period	0	1	0	4
Other comprehensive (loss) income	0	0	0	(3)
Balance at end of period	0	1	0	1
Total accumulated other comprehensive loss
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]
Balance at beginning of period	(1,224)	(949)	(1,285)	(768)
Balance at end of period	$ (1,561)	$ (1,212)	$ (1,561)	$ (1,212)

Treasury Stock (Details)

Treasury Stock (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Equity [Abstract]
Treasury stock (in shares)	656,844,000	655,306,000
Cost of common stock held in treasury	$ 1,486	$ 1,484

Earnings per Share - Basic Earn

Earnings per Share - Basic Earnings Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Basic weighted-average shares (in shares)	24,187,000	24,171,000	24,183,000	24,162,000
Conversion of unsecured loan notes (in shares)	0	0	0	0
Unexercised options and unvested RSUs (in shares)	0	417,000	0	0
Diluted weighted-average shares (in shares)	24,187,000	24,588,000	24,183,000	24,162,000

Earnings per Share - Narrative

Earnings per Share - Narrative (Details) - shares	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share (in shares)	1,269,000	1,286,000

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	May 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 138,000	$ 97,000	$ 357,000	$ 135,000
Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares originally reserved (in shares)					5,600,676
Number of shares available for grant (in shares)	2,092,136		2,092,136
Incentive Plan | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			10 years
Award service period (in years)			4 years
Unrecognized compensation costs	$ 0		$ 0
Incentive Plan | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 489,000		$ 489,000
Unrecognized compensation cost, period of recognition (in years)			1 year 6 months 23 days
Incentive Plan | Restricted Stock Units (RSUs) | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			2 years
Incentive Plan | Restricted Stock Units (RSUs) | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			4 years
Incentive Plan | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of stock vested			$ 22,000
Incentive Plan | Second Anniversary of Award Date | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of options vesting	50.00%		50.00%
Incentive Plan | Third Anniversary of Award Date | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of options vesting	25.00%		25.00%
Incentive Plan | Fourth Anniversary of Award Date | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of options vesting	25.00%		25.00%
2019 Executive Performance RSU Award Agreement | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			3 years
Required operating income			$ 2,000,000
Period before vesting begins			1 year
Deferred Plan | Deferred Compensation
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense			$ 0	$ 0

Stock-Based Compensation - Expe

Stock-Based Compensation - Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Payment Arrangement [Abstract]
Stock options and restricted stock units, net of forfeited	$ 138	$ 97	$ 357	$ 135
Tax benefit of stock-based compensation expense	0	0	0	0
After-tax effect of stock-based compensation	$ 138	$ 97	$ 357	$ 135

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity (Details) - Stock Options - Incentive Plan	9 Months Ended
	Sep. 30, 2019USD ($)$ / sharesshares
Number of Options
Outstanding, beginning of period (in shares) | shares	932,500
Granted (in shares) | shares	0
Exercised (in shares) | shares	0
Expired or forfeited (in shares) | shares	(185,000)
Outstanding, end of period (in shares) | shares	747,500
Number of Shares, exercisable (in shares) | shares	747,500
Weighted- Average Exercise Price
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 4.68
Granted (in dollars per share) | $ / shares	0
Exercised (in dollars per share) | $ / shares	0
Expired or forfeited (in dollars per share) | $ / shares	10.14
Outstanding, end of period (in dollars per share) | $ / shares	3.33
Weighted average exercise price, exercisable (in dollars per share) | $ / shares	$ 3.33
Weighted- Average Remaining Contractual Term, Outstanding	4 years 11 months 23 days
Weighted- Average Remaining Contractual Term, Exercisable	4 years 11 months 23 days
Aggregate Intrinsic Value, Outstanding | $	$ 4
Aggregate Intrinsic Value, Exercisable | $	4
Unrecognized compensation costs | $	$ 0

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Unit Activity (Details) - Incentive Plan - Restricted Stock	9 Months Ended
	Sep. 30, 2019$ / sharesshares
Shares (in shares)
Beginning balance (in shares) | shares	1,110,277
Granted (in shares) | shares	228,135
Forfeited (in shares) | shares	0
Vested (in shares) | shares	(17,777)
Ending balance (in shares) | shares	1,320,635
Weighted Average Grant Date Fair Value (in Dollars per share)
Beginning balance (in dollars per share) | $ / shares	$ 1.21
Granted (in dollars per share) | $ / shares	1.52
Forfeited (in dollars per share) | $ / shares	0
Vested (in dollars per share) | $ / shares	1.59
Ending balance (in dollars per share) | $ / shares	$ 1.26

Debt Financing (Details)

Debt Financing (Details) - Cash Collateral Security Agreement - Standby Letters of Credit - USD ($) $ in Thousands	Jun. 19, 2019	Sep. 30, 2019
Line of Credit Facility [Line Items]
Cash collateral, percentage of face amount of outstanding standby letters of credit	105.00%
Letters of credit, amount outstanding		$ 2,361
Restricted cash		$ 2,482
LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate (as percent)	2.50%

Business Segment and Geograph_3

Business Segment and Geographic Financial Data (Details)	9 Months Ended
	Sep. 30, 2019segment
Segment Reporting [Abstract]
Number of reportable segments	2

Business Segment and Geograph_4

Business Segment and Geographic Financial Data - Reporting Segment Net Sales and Gross Margin (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Revenues from external customers	$ 6,452	$ 16,070	$ 25,555	$ 40,708
Cost of sales	(3,563)	(10,654)	(14,754)	(26,545)
Gross margin	2,889	5,416	10,801	14,163
Selling, general and administrative	(3,822)	(4,105)	(12,735)	(13,789)
Restructuring charge	0	0	(625)	0
Research and development	(352)	(265)	(823)	(814)
Intangible assets abandonment	(76)	0	(127)	(317)
Operating income (loss) from continuing operations	(1,361)	1,046	(3,509)	(757)
Air Pollution Control Segment
Segment Reporting Information [Line Items]
Revenues from external customers	1,816	10,882	12,408	27,872
Cost of sales	(1,197)	(8,116)	(8,061)	(20,040)
Gross margin	619	2,766	4,347	7,832
Selling, general and administrative	0	0	0	0
Restructuring charge			0
Research and development	0	0	0	0
Intangible assets abandonment	0			0
Operating income (loss) from continuing operations	619	2,766	4,347	7,832
FUEL CHEM Segment
Segment Reporting Information [Line Items]
Revenues from external customers	4,636	5,188	13,147	12,836
Cost of sales	(2,366)	(2,538)	(6,693)	(6,505)
Gross margin	2,270	2,650	6,454	6,331
Selling, general and administrative	0	0	0	0
Restructuring charge			0
Research and development	0	0	0	0
Intangible assets abandonment	0			0
Operating income (loss) from continuing operations	2,270	2,650	6,454	6,331
Other
Segment Reporting Information [Line Items]
Revenues from external customers		0	0	0
Cost of sales	0	0	0	0
Gross margin	0	0	0	0
Selling, general and administrative	(3,822)	(4,105)	(12,735)	(13,789)
Restructuring charge			(625)
Research and development	(352)	(265)	(823)	(814)
Intangible assets abandonment	(76)		(127)	(317)
Operating income (loss) from continuing operations	$ (4,250)	$ (4,370)	$ (14,310)	$ (14,920)

Business Segment and Geograph_5

Business Segment and Geographic Financial Data - Operations by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Revenues	$ 6,452	$ 16,070	$ 25,555	$ 40,708
United States
Revenues:
Revenues	5,727	11,629	22,104	30,701
Foreign
Revenues:
Revenues	$ 725	$ 4,441	$ 3,451	$ 10,007

Business Segment and Geograph_6

Business Segment and Geographic Financial Data - Assets by Geographic Area (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
ASSETS
Assets	$ 37,879	$ 51,719
United States
ASSETS
Assets	29,437	36,784
Foreign
ASSETS
Assets	$ 8,442	$ 14,935

Leases - Adoption of ASC 842 (D

Leases - Adoption of ASC 842 (Details) - USD ($)	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
ASSETS
Right-of-use operating lease assets	$ 1,104,000	$ 1,592,000	$ 0
Liabilities
Other accrued liabilities	2,419,000	6,077,000	6,099,000
Operating lease liabilities - current	376,000	650,000	0
Operating lease liabilities - non-current	715,000	942,000	0
Equity
Accumulated deficit	$ (105,985,000)	(102,473,000)	$ (102,495,000)
Accounting Standards Update 2016-02
ASSETS
Right-of-use operating lease assets		1,592,000
Liabilities
Other accrued liabilities		(22,000)
Operating lease liabilities - current		650,000
Operating lease liabilities - non-current		942,000
Equity
Accumulated deficit		$ 22,000

Leases - Lease Cost (Details)

Leases - Lease Cost (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2019USD ($)lease_arrangement
Lessee, Lease, Description [Line Items]
Number of lease arrangements | lease_arrangement		9
Operating lease cost	$ 171	$ 514
Short-term lease cost	1	135
Total lease cost	$ 172	$ 649
Weighted average remaining lease term	4 years 4 months	4 years 4 months
Weighted average discount rate	3.52%	3.52%
Minimum
Lessee, Lease, Description [Line Items]
Term of lease	1 year	1 year
Maximum
Lessee, Lease, Description [Line Items]
Term of lease	6 years	6 years

Leases - Lease Maturity (Detail

Leases - Lease Maturity (Details) $ in Thousands	Sep. 30, 2019USD ($)
Leases [Abstract]
2019 (excluding the nine months ended September 30, 2019)	$ 160
2020	310
2021	218
2022	165
2023	152
Thereafter	196
Total lease payments	1,201
Less imputed interest	(110)
Total	$ 1,091

Leases - Balance Sheet Classifi

Leases - Balance Sheet Classification (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Leases [Abstract]
Operating lease liabilities - current	$ 376	$ 650	$ 0
Operating lease liabilities - non-current	715	$ 942	$ 0
Total operating lease liabilities	$ 1,091

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Cash paid for amounts included in the measurement of lease liabilities	$ 162	$ 505
Leased assets obtained in exchange for operating lease liabilities	$ 154	$ 482

Accrued Liabilities (Details)

Accrued Liabilities (Details) - USD ($)	Sep. 30, 2019	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Payables and Accruals [Abstract]
Contract liabilities (Note 3)	$ 682,000			$ 1,234,000
Accrued remediation contingency (Note 14)	760,000	$ 1,223,000		0
Other accrued liabilities	977,000			4,865,000
Total other accrued liabilities	$ 2,419,000		$ 6,077,000	$ 6,099,000

Contingencies (Details)

Contingencies (Details) - USD ($)	3 Months Ended		9 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Loss Contingencies [Line Items]
Expected insurance proceeds		$ 973,000
Accrued remediation contingency		1,223,000	$ 760,000		$ 0
Insurance deductible		$ 250,000
Addition to claims receivable	$ 1,005,000
Addition to accrued liability	$ 1,005,000
Receivable from insurance carrier			1,991,000		0
Non-conformance accrual			760,000
Accounts receivable			10,124,000		$ 18,399,000
Change in warranty liability balance			0	$ 0
Warranty liability balance			159,000	$ 159,000
Customer One
Loss Contingencies [Line Items]
Accounts receivable			$ 500,000

Income Taxes (Details)

Income Taxes (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Effective income tax rate	0.00%	0.00%	0.00%	0.00%
Federal tax rate (as a percent)	21.00%		21.00%
Unrecognized tax benefits	$ 0		$ 0		$ 0

Goodwill and Other Intangibles

Goodwill and Other Intangibles (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)reporting_unit	Sep. 30, 2018USD ($)	Dec. 31, 2018USD ($)
Goodwill [Line Items]
Number of reporting units | reporting_unit			2
Goodwill	$ 2,116,000		$ 2,116,000		$ 2,116,000
Goodwill impairments			0	$ 0
Intangible assets abandonment	76,000	$ 0	127,000	317,000
Air Pollution Control Segment
Goodwill [Line Items]
Goodwill	0		$ 0
Intangible assets abandonment	0			0
FUEL CHEM Segment
Goodwill [Line Items]
Goodwill					$ 2,116,000
Intangible assets abandonment	$ 0			$ 0