Fuel Tech (FTEK) 10-Q 10 Aug 22 2022 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2022	Jul. 31, 2022
Document Information [Line Items]
Entity Central Index Key	0000846913
Entity Registrant Name	FUEL TECH, INC.
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2022
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2022
Document Transition Report	false
Entity File Number	001-33059
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-5657551
Entity Address, Address Line One	27601 Bella Vista Parkway
Entity Address, City or Town	Warrenville
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60555-1617
City Area Code	630
Local Phone Number	845-4500
Title of 12(b) Security	Common Stock
Trading Symbol	FTEK
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		30,296,297

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 31,308	$ 35,893
Restricted cash and cash equivalents	1,990	891
Accounts receivable, net	6,424	3,259
Inventories, net	405	348
Prepaid expenses and other current assets	856	1,074
Total current assets	40,983	41,465
Property and equipment, net of accumulated depreciation of $18,379 and $18,243, respectively	4,556	4,609
Goodwill	2,116	2,116
Other intangible assets, net of accumulated amortization of $369 and $341, respectively	416	448
Restricted cash	0	270
Right-of-use operating lease assets	236	242
Other assets	811	824
Total assets	49,118	49,974
Current liabilities:
Accounts payable	2,348	1,561
Accrued liabilities:
Operating lease liabilities - current	118	113
Employee compensation	677	688
Other accrued liabilities	887	861
Total current liabilities	4,030	3,223
Operating lease liabilities - non-current	111	122
Deferred income taxes, net	139	139
Other liabilities	255	290
Total liabilities	4,535	3,774
Stockholders’ equity:
Common stock, $.01 par value, 40,000,000 shares authorized, 31,272,303 and 31,227,300 shares issued, and 30,296,297 and 30,263,791 shares outstanding, respectively	313	312
Additional paid-in capital	164,244	164,199
Accumulated deficit	(115,903)	(114,549)
Accumulated other comprehensive loss	(1,896)	(1,604)
Nil coupon perpetual loan notes	76	76
Treasury stock, at cost	(2,251)	(2,234)
Total stockholders’ equity	44,583	46,200
Total liabilities and stockholders’ equity	$ 49,118	$ 49,974

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Accumulated depreciation	$ 18,379	$ 18,243
Accumulated amortization, intangible assets	$ 369	$ 341
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)	31,272,303	31,227,300
Common stock, shares outstanding (in shares)	30,296,297	30,263,791

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenues	$ 6,368	$ 5,218	$ 11,903	$ 10,251
Costs and expenses:
Cost of sales	3,690	2,635	6,935	5,310
Selling, general and administrative	2,874	2,957	5,928	6,057
Research and development	289	315	509	730
Costs and Expenses, Total	6,853	5,907	13,372	12,097
Operating loss	(485)	(689)	(1,469)	(1,846)
Interest expense	(4)	(5)	(9)	(9)
Interest income	8	2	9	3
Other income (expense), net	134	(76)	124	1,482
Loss before income taxes	(347)	(768)	(1,345)	(370)
Income tax expense	(9)	(10)	(9)	(10)
Net loss	$ (356)	$ (778)	$ (1,354)	$ (380)
Net loss per common share:
Basic net loss per common share (in dollars per share)	$ (0.01)	$ (0.03)	$ (0.04)	$ (0.01)
Diluted net loss per common share (in dollars per share)	$ (0.01)	$ (0.03)	$ (0.04)	$ (0.01)
Weighted-average number of common shares outstanding:
Basic (in shares)	30,296,000	30,264,000	30,282,000	28,895,000
Diluted (in shares)	30,296,000	30,264,000	30,282,000	28,895,000

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Net loss	$ (356)	$ (778)	$ (1,354)	$ (380)
Other comprehensive (loss) income:
Foreign currency translation adjustments	(222)	133	(292)	(60)
Comprehensive loss	$ (578)	$ (645)	$ (1,646)	$ (440)

Condensed Statements of Stockho

Condensed Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Common Stock Outstanding [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Nil Coupon Perpetual Loan Notes [Member]	Treasury Stock [Member]	Total
Balance (in shares) at Dec. 31, 2020	25,229
Balance at Dec. 31, 2020	$ 262	$ 140,138	$ (114,603)	$ (1,370)	$ 76	$ (2,182)	$ 22,321
Net income (loss)	0	0	398	0	0	0	398
Foreign currency translation adjustments	0	0	0	(193)	0	0	(193)
Stock compensation expense	$ 0	20	0	0	0	0	20
Common stock issued in connection with private placement, net (in shares)	5,000
Common stock issued in connection with private placement, net	$ 50	23,979	0	0	0	0	24,029
Common shares issued upon vesting of restricted stock units (in shares)	50
Common shares issued upon vesting of restricted stock units	$ 0	0	0	0	0	0	0
Taxes paid on behalf of equity award participants (in shares)	(15)
Taxes paid on behalf of equity award participants	$ 0	0	0	0	0	(52)	(52)
Balance (in shares) at Mar. 31, 2021	30,264
Balance at Mar. 31, 2021	$ 312	164,137	(114,205)	(1,563)	76	(2,234)	46,523
Balance (in shares) at Dec. 31, 2020	25,229
Balance at Dec. 31, 2020	$ 262	140,138	(114,603)	(1,370)	76	(2,182)	22,321
Net income (loss)							(380)
Foreign currency translation adjustments							(60)
Balance (in shares) at Jun. 30, 2021	30,264
Balance at Jun. 30, 2021	$ 312	164,157	(114,983)	(1,430)	76	(2,234)	45,898
Balance (in shares) at Mar. 31, 2021	30,264
Balance at Mar. 31, 2021	$ 312	164,137	(114,205)	(1,563)	76	(2,234)	46,523
Net income (loss)	0	0	(778)	0	0	0	(778)
Foreign currency translation adjustments	0	0	0	133	0	0	133
Stock compensation expense	$ 0	20	0	0	0	0	20
Balance (in shares) at Jun. 30, 2021	30,264
Balance at Jun. 30, 2021	$ 312	164,157	(114,983)	(1,430)	76	(2,234)	45,898
Balance (in shares) at Dec. 31, 2021	30,264
Balance at Dec. 31, 2021	$ 312	164,199	(114,549)	(1,604)	76	(2,234)	46,200
Net income (loss)	0	0	(998)	0	0	0	(998)
Foreign currency translation adjustments	0	0	0	(70)	0	0	(70)
Stock compensation expense	$ 0	18	0	0	0	0	18
Common shares issued upon vesting of restricted stock units (in shares)	45
Common shares issued upon vesting of restricted stock units	$ 1	(1)	0	0	0	0	0
Taxes paid on behalf of equity award participants (in shares)	(13)
Taxes paid on behalf of equity award participants	$ 0	0	0	0	0	(17)	(17)
Balance (in shares) at Mar. 31, 2022	30,296
Balance at Mar. 31, 2022	$ 313	164,216	(115,547)	(1,674)	76	(2,251)	45,133
Balance (in shares) at Dec. 31, 2021	30,264
Balance at Dec. 31, 2021	$ 312	164,199	(114,549)	(1,604)	76	(2,234)	46,200
Net income (loss)							(1,354)
Foreign currency translation adjustments							(292)
Balance (in shares) at Jun. 30, 2022	30,296
Balance at Jun. 30, 2022	$ 313	164,244	(115,903)	(1,896)	76	(2,251)	44,583
Balance (in shares) at Mar. 31, 2022	30,296
Balance at Mar. 31, 2022	$ 313	164,216	(115,547)	(1,674)	76	(2,251)	45,133
Net income (loss)	0	0	(356)	0	0	0	(356)
Foreign currency translation adjustments	0	0	0	(222)	0	0	(222)
Stock compensation expense	$ 0	28	0	0	0	0	28
Balance (in shares) at Jun. 30, 2022	30,296
Balance at Jun. 30, 2022	$ 313	$ 164,244	$ (115,903)	$ (1,896)	$ 76	$ (2,251)	$ 44,583

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Operating Activities
Net loss	$ (1,354)	$ (380)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation	182	319
Amortization	50	71
Loss on disposal of equipment	0	13
Provision for doubtful accounts, net of recoveries	43	23
Stock-based compensation, net of forfeitures	46	40
Changes in operating assets and liabilities:
Accounts receivable	(3,245)	3,079
Inventories	(58)	(97)
Prepaid expenses, other current assets and other non-current assets	205	681
Accounts payable	812	(943)
Accrued liabilities and other non-current liabilities	(2)	(1,021)
Net cash (used in) provided by operating activities	(3,321)	229
Investing Activities
Purchases of equipment and patents	(138)	(237)
Net cash used in investing activities	(138)	(237)
Financing Activities
Proceeds from sale of common stock issued in connection with private placement	0	25,812
Costs related to sale of common stock issued in connection with private placement	0	(1,783)
Taxes paid on behalf of equity award participants	(17)	(52)
Net cash (used in) provided by financing activities	(17)	23,977
Effect of exchange rate fluctuations on cash	(280)	(13)
Net (decrease) increase in cash, cash equivalents and restricted cash and cash equivalents	(3,756)	23,956
Cash, cash equivalents, and restricted cash and cash equivalents at beginning of period (Note 2)	37,054	12,606
Cash, cash equivalents and restricted cash and cash equivalents at end of period (Note 2)	33,298	36,562
Paycheck Protection Program CARES Act [Member]
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Gain of forgiveness on Paycheck Protection Plan Loan	$ 0	$ (1,556)

Note 1 - General

Note 1 - General	6 Months Ended
	Jun. 30, 2022
Notes to Financial Statements
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	1. Organization Fuel Tech, Inc. and subsidiaries ("Fuel Tech", the "Company", "we", "us" or "our") develops and provides proprietary technologies for air pollution control, process optimization, water treatment, and advanced engineering services. These technologies enable customers to operate in a cost-effective and environmentally sustainable manner. The Company’s nitrogen oxide (NOx) reduction technologies reduce nitrogen oxide emissions from boilers, furnaces, and other stationary combustion sources. To reduce NOx emissions, our technologies utilize advanced combustion modification techniques and post-combustion NOx control approaches including non-catalytic, catalytic, and combined systems. The Company also provides solutions for the mitigation of particulate matter, including particulate control with electrostatic precipitator products and services, and using flue gas conditioning systems which modify the ash properties of particulate for improved collection efficiency. The Company’s FUEL CHEM® technology improves the efficiency, reliability, fuel flexibility, boiler heat rate, and environmental status of combustion units by controlling slagging, fouling, corrosion, and opacity. Water treatment technologies include DGI™ Dissolved Gas Infusion Systems which utilize a patented nozzle to deliver supersaturated oxygen solutions and other gas-water combinations to target process applications or environmental issues. This infusion process has a variety of applications in the water and wastewater industries, including remediation, aeration, biological treatment, and wastewater odor management. Many of Fuel Tech’s products and services rely heavily on the Company’s Computational Fluid Dynamics modeling capabilities, which are enhanced by internally developed, high-end visualization software. 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 10 X not three six June 30, 2022 not December 31, 2022. 10 December 31, 2021 COVID- 19 The effects of the coronavirus (COVID- 19 not may third Geopolitical events and global economic sanctions resulting from the ongoing conflict between Russia and Ukraine may may Management cannot predict the full impact of the COVID- 19

Note 2 - Summary of Significant

Note 2 - Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2022
Notes to Financial Statements
Significant Accounting Policies [Text Block]	2. Restricted cash and cash equivalents Restricted cash as of June 30, 2021 June 2022, 10 June 30, 2022, relating to existing standby letters of credit with varying maturity dates and expire no June 30, 2023. The following table provides a reconciliation of cash, cash equivalents, and restricted cash and cash equivalents reported within the Condensed Consolidated Balance Sheets that sum to the total of the same such amounts shown in the Condensed Consolidated Statements of Cash Flows: June 30, June 30, 2022 2021 Cash $ 23,298 $ 36,194 Cash equivalents 8,010 — Restricted cash and cash equivalents included in current assets 1,990 98 Restricted cash included in long-term assets — 270 Total cash, cash equivalents, and restricted cash and cash equivalents shown in the Condensed Consolidated Statements of Cash Flows $ 33,298 $ 36,562 Investments In June 2022, June 30, 2022, 10 We consider all highly liquid debt investments with original maturities from the date of purchase of three 3 Our investments in debt securities consist of Unites States (US) Treasury securities, including Notes, Bonds, and Bills, and US Government Agency securities, that are designated as held-to-maturity (HTM) and stated at amortized cost. The Company has the positive intent and ability to hold these investments to maturity and does not three three one one Inventories Inventories consist primarily of equipment constructed for resale and spare parts and are stated at the lower of cost or net realizable value, using the weighted-average cost method. At June 30, 2022 and December 31, 2021 , inventory included equipment constructed for resale of $ and $ , respectively, and spare parts, net of reserves of $ and $ , respectively. Usage is recorded in cost of sales in the period that parts were issued to a project, used to service equipment, or sold to customers. In not

Note 3 - Revenue

Note 3 - Revenue	6 Months Ended
	Jun. 30, 2022
Notes to Financial Statements
Revenue from Contract with Customer [Text Block]	3. Disaggregated Revenue by Product Technology The following table presents our revenues disaggregated by product technology: Three Months Ended Six Months Ended June 30, June 30, 2022 2021 2022 2021 Air Pollution Control Technology solutions $ 1,966 $ 223 $ 3,807 $ 596 Spare parts 262 236 358 416 Ancillary revenue 510 527 777 881 Total Air Pollution Control technology revenues 2,738 986 4,942 1,893 FUEL CHEM FUEL CHEM technology solutions 3,630 4,232 6,961 8,358 Total Revenues $ 6,368 $ 5,218 $ 11,903 $ 10,251 Disaggregated Revenue by Geography The following table presents our revenues disaggregated by geography, based on t he location of the end-user: Three Months Ended Six Months Ended June 30, June 30, 2022 2021 2022 2021 United States $ 4,279 $ 4,588 $ 7,967 $ 9,051 Foreign Revenues Latin America 60 142 129 217 Europe 922 301 1,326 676 Asia 1,107 187 2,481 307 Total Foreign Revenues 2,089 630 3,936 1,200 Total Revenues $ 6,368 $ 5,218 $ 11,903 $ 10,251 Timing of Revenue Recognition The following table presents the timing of our revenue recognition: Three Months Ended Six Months Ended June 30, June 30, 2022 2021 2022 2021 Products transferred at a point in time $ 4,402 $ 4,995 $ 8,096 $ 9,655 Products and services transferred over time 1,966 223 3,807 596 Total Revenues $ 6,368 $ 5,218 $ 11,903 $ 10,251 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 Condensed Consolidated Balance Sheets. In our Air Pollution Control (APC) 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. For the FUEL CHEM technology segment, deliveries made in the current period but billed in subsequent periods are also considered unbilled receivables (contract assets). These assets are reported on the Condensed Consolidated Balance Sheets on a contract-by-contract basis at the end of each reporting period. At June 30, 2022 December 31, 2021 December 31, 2020, December 31, 2020, June 30, 2022 December 31, 2021 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 Condensed Consolidated Balance Sheets on a contract-by-contract basis at the end of each reporting period. Contract liabilities were $578, $390, and $850 at June 30, 2022 December 31, 2021 December 31, 2020, Changes in the contract asset and liability balances during the six June 30, 2022 not three six June 30, 2022 three six June 30, 2021 As of June 30, 2022 December 31, 2021 Remaining Performance Obligations Remaining performance obligations represents the transaction price of APC technology booked orders for which work has not As of June 30, 2022 , the aggregate amount of the transaction price allocated to remaining performance obligations was $ . The Company expects to recognize revenue on approximately $ 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 June 30, 2022 December 31, 2021 Trade receivables $ 5,500 $ 2,122 Unbilled receivables 1,106 1,277 Other short-term receivables 78 83 Allowance for doubtful accounts (260 ) (223 ) Total accounts receivable $ 6,424 $ 3,259

Note 4 - Restructuring Activiti

Note 4 - Restructuring Activities	6 Months Ended
	Jun. 30, 2022
Notes to Financial Statements
Restructuring and Related Activities Disclosure [Text Block]	4. On January 18, 2019, June 30, 2022 6 The following table presents our revenues and net loss for 2022 2021 Three Months Ended Six Months Ended June 30, June 30, 2022 2021 2022 2021 Total revenues $ — $ 4 $ 1 $ 15 Net loss (38 ) (63 ) (51 ) (38 ) 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 June 30, 2022 December 31, 2021 Total assets $ 1,121 $ 1,235 Total liabilities 85 92 Total net assets $ 1,036 $ 1,143

Note 5 - Accumulated Other Comp

Note 5 - Accumulated Other Comprehensive Loss	6 Months Ended
	Jun. 30, 2022
Notes to Financial Statements
Comprehensive Income (Loss) Note [Text Block]	5. The changes in accumulated other comprehensive loss by component were as follows: Three Months Ended Six Months Ended June 30, June 30, 2022 2021 2022 2021 Foreign currency translation Balance at beginning of period $ (1,674 ) $ (1,563 ) $ (1,604 ) $ (1,370 ) Other comprehensive (loss) income: Foreign currency translation adjustments (1) (222 ) 133 (292 ) (60 ) Total accumulated other comprehensive loss $ (1,896 ) $ (1,430 ) $ (1,896 ) $ (1,430 ) ( 1 In all periods presented, there were no no

Note 6 - Treasury Stock

Note 6 - Treasury Stock	6 Months Ended
	Jun. 30, 2022
Notes to Financial Statements
Treasury Stock [Text Block]	6. Common stock held in treasury totaled 976,006 and 963,509 with a cost of $2,251 and $2,234 at June 30, 2022 December 31, 2021

Note 7 - Earnings Per Share

Note 7 - Earnings Per Share	6 Months Ended
	Jun. 30, 2022
Notes to Financial Statements
Earnings Per Share [Text Block]	7. Basic earnings per share excludes the dilutive effects of stock options, restricted stock units (RSUs), warrants, and the nil nil d. For the three six June 30, 2022 2021 , basic earnings per share is equal to diluted earnings per share because all outstanding stock awards, warrants, and convertible loan notes are considered anti-dilutive during periods of net loss. The following table sets forth the weighted-average shares used in calculating the earnings per share for the three six June 30, 2022 2021 Three Months Ended Six Months Ended June 30, June 30, 2022 2021 2022 2021 Basic weighted-average shares 30,296,000 30,264,000 30,282,000 28,895,000 Conversion of unsecured loan notes — — — — Unexercised options and unvested RSUs — — — — Diluted weighted-average shares 30,296,000 30,264,000 30,282,000 28,895,000 For the three six June 30, 2022 , Fuel Tech had weighted-average outstanding equity awards of and , respectively, and warrants of in both periods, which were antidilutive for the purpose of the calculation of diluted earnings per share. For the three six June 30, 2022 , Fuel Tech had and , respectively, of incremental equity awards that were excluded from the computation of diluted earnings per share as the inclusion of such would have been anti-dilutive due to a net loss in the period. These equity awards could potentially dilute basic earnings per share in future years. Fuel Tech had 160,000 weighted average equity awards outstanding at June 30, 2021 not

Note 8 - Stock-based Compensati

Note 8 - Stock-based Compensation	6 Months Ended
	Jun. 30, 2022
Notes to Financial Statements
Share-Based Payment Arrangement [Text Block]	8. Under our stock-based employee compensation plan, referred to as the Fuel Tech, Inc. 2014 may may may June 30, 2022 We did not three six June 30, 2022 2021. no three six June 30, 2022 2021. no Stock-based compensation is included in selling, general, and administrative costs in our Condensed Consolidated Statements of Operations. The components of stock-based compensation for the three six June 30, 2022 2021 Three Months Ended Six Months Ended June 30, June 30, 2022 2021 2022 2021 Stock options and restricted stock units, net of forfeitures $ 28 $ 20 $ 46 $ 40 After-tax effect of stock-based compensation $ 28 $ 20 $ 46 $ 40 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 third fourth four 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 2 3 Stock option activity for Fuel Tech’s Incentive Plans for the six June 30, 2022 Weighted- Average Number Weighted- Remaining Aggregate of Average Contractual Intrinsic Options Exercise Price Term Value Outstanding on January 1, 2022 434,500 $ 3.05 Granted — — Exercised — — Expired or forfeited (50,000 ) 3.55 Outstanding on June 30, 2022 384,500 $ 2.98 2.94 $ 24 Exercisable on June 30, 2022 384,500 $ 2.98 2.94 $ 24 As of June 30, 2022 Restricted Stock Units RSUs granted to employees vest over time based on continued service (typically vesting over a period between two four ars), and RSUs granted to directors vest after a one d. At June 30, 2022 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 yea A summary of restricted stock unit activity for the six June 30, 2022 Weighted Average Grant Date Shares Fair Value Unvested restricted stock units at January 1, 2022 45,003 $ 1.51 Granted 807,048 1.32 Forfeited — — Vested (45,003 ) 1.51 Unvested restricted stock units at June 30, 2022 807,048 $ 1.32 The fair value of restricted stock that vested during the six June 30, 2022 Deferred Directors Fees In addition to the Incentive Plans, Fuel Tech has a Deferred Compensation Plan 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 Accounting Standards Codification (ASC) 718, six June 30, 2022 2021

Note 9 - Warrants

Note 9 - Warrants	6 Months Ended
	Jun. 30, 2022
Notes to Financial Statements
Warrants Disclosure [Text Block]	9. The following table summarizes information about warrants outstanding and exercisable at June 30, 2022 Range of Exercise Price Number Outstanding/Exercisable Weighted Average Remaining Life in Years Weighted Average Exercise Price $5.10 2,500,000 4.12 $ 5.10 $6.45 350,000 4.12 $ 6.45 2,850,000

Note 10 - Debt Financing

Note 10 - Debt Financing	6 Months Ended
	Jun. 30, 2022
Notes to Financial Statements
Debt Disclosure [Text Block]	10. On June 30, 2022, no June 30, 2022, under the Investment Collateral Security agreement. At June 30, 2022, . Fuel Tech is committed to reimbursing the issuing bank for any payments made by the bank under these instruments. On April 17, 2020, April 15, 2020 On January 8, 2021, 470, 835 30.

Note 11 - Business Segment and

Note 11 - Business Segment and Geographic Financial Data	6 Months Ended
	Jun. 30, 2022
Notes to Financial Statements
Segment Reporting Disclosure [Text Block]	11. Business Segment Financial Data We segregate our financial results into two two • T he Air Pollution Control technology segment includes technologies to reduce NOx emissions in flue gas generated by the firing of natural gas or coal from boilers, incinerators, furnaces, and other stationary combustion sources. These include Over-Fire Air systems, NOxOUT ® and HERT™ Selective Non-Catalytic Reduction systems, and Selective Catalytic Reduction (SCR) systems. Our SCR systems can also include Ammonia Injection Grid, and Graduated Straightening Grid GSG™ systems to provide high NOx reductions at significantly lower capital and operating costs than conventional SCR systems. ULTRA ® technology creates ammonia at a plant site using safe urea for use with any SCR application. Electrostatic Precipitator technologies make use of electrostatic precipitator products and services to reduce particulate matter. 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 ® ® The “Other” classification includes those profit and loss items not no 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 10 not Information about reporting segment net sales and gross margin from operations are provided below: Air Pollution FUEL CHEM Three months ended June 30, 2022 Control Segment Segment Other Total Revenues from external customers $ 2,738 $ 3,630 $ — $ 6,368 Cost of sales (1,802 ) (1,888 ) — (3,690 ) Gross margin 936 1,742 — 2,678 Selling, general and administrative — — (2,874 ) (2,874 ) Research and development — — (289 ) (289 ) Operating income (loss) from operations $ 936 $ 1,742 $ (3,163 ) $ (485 ) Air Pollution FUEL CHEM Three months ended June 30, 2021 Control Segment Segment Other Total Revenues from external customers $ 986 $ 4,232 $ — $ 5,218 Cost of sales (507 ) (2,128 ) — (2,635 ) Gross margin 479 2,104 — 2,583 Selling, general and administrative — — (2,957 ) (2,957 ) Research and development — — (315 ) (315 ) Operating income (loss) from operations $ 479 $ 2,104 $ (3,272 ) $ (689 ) Air Pollution FUEL CHEM Six months ended June 30, 2022 Control Segment Segment Other Total Revenues from external customers $ 4,942 $ 6,961 $ — $ 11,903 Cost of sales (3,231 ) (3,704 ) — (6,935 ) Gross margin 1,711 3,257 — 4,968 Selling, general and administrative — — (5,928 ) (5,928 ) Research and development — — (509 ) (509 ) Operating income (loss) from operations $ 1,711 $ 3,257 $ (6,437 ) $ (1,469 ) Air Pollution FUEL CHEM Six months ended June 30, 2021 Control Segment Segment Other Total Revenues from external customers $ 1,893 $ 8,358 $ — $ 10,251 Cost of sales (1,038 ) (4,272 ) — (5,310 ) Gross margin 855 4,086 — 4,941 Selling, general and administrative — — (6,057 ) (6,057 ) Research and development — — (730 ) (730 ) Operating income (loss) from operations $ 855 $ 4,086 $ (6,787 ) $ (1,846 ) 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 end-user. Assets are those directly associated with operations of the geographic area. Three Months Ended Six Months Ended June 30, June 30, 2022 2021 2022 2021 Revenues: United States $ 4,279 $ 4,588 $ 7,967 $ 9,051 Foreign 2,089 630 3,936 1,200 $ 6,368 $ 5,218 $ 11,903 $ 10,251 June 30, December 31, 2022 2021 Assets: United States $ 45,934 $ 46,271 Foreign 3,184 3,703 $ 49,118 $ 49,974

Note 12 - Accrued Liabilities

Note 12 - Accrued Liabilities	6 Months Ended
	Jun. 30, 2022
Notes to Financial Statements
Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block]	12. The components of other accrued liabilities are as follows: As of June 30, 2022 December 31, 2021 Contract liabilities (Note 3) $ 578 $ 390 Other accrued liabilities 309 471 Total other accrued liabilities $ 887 $ 861

Note 13 - Commitments and Conti

Note 13 - Commitments and Contingencies	6 Months Ended
	Jun. 30, 2022
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	13. 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 not not may 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 not 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 included in the other accrued liabilities line of the Condensed Consolidated Balance Sheets during the six June 30, 2022 2021 June 30, 2022 December 31, 2021

Note 14 - Income Taxes

Note 14 - Income Taxes	6 Months Ended
	Jun. 30, 2022
Notes to Financial Statements
Income Tax Disclosure [Text Block]	14. The Company’s effective tax rate is approximately 0.7% and for the six month periods ended June 30, 2022 2021 six June 30, 2022 2021 no six June 30, 2022 2021 Income generated in the six months ended June 30, 2021 Fuel Tech had no unrecognized tax benefits as of June 30, 2022 December 31, 2021

Note 15 - Subsequent Events

Note 15 - Subsequent Events	6 Months Ended
	Jun. 30, 2022
Notes to Financial Statements
Subsequent Events [Text Block]	15. The Company has evaluated subsequent events through the filing of this Quarterly Report on Form 10 no

Significant Accounting Policies

Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]	Restricted cash and cash equivalents Restricted cash as of June 30, 2021 June 2022, 10 June 30, 2022, relating to existing standby letters of credit with varying maturity dates and expire no June 30, 2023. The following table provides a reconciliation of cash, cash equivalents, and restricted cash and cash equivalents reported within the Condensed Consolidated Balance Sheets that sum to the total of the same such amounts shown in the Condensed Consolidated Statements of Cash Flows: June 30, June 30, 2022 2021 Cash $ 23,298 $ 36,194 Cash equivalents 8,010 — Restricted cash and cash equivalents included in current assets 1,990 98 Restricted cash included in long-term assets — 270 Total cash, cash equivalents, and restricted cash and cash equivalents shown in the Condensed Consolidated Statements of Cash Flows $ 33,298 $ 36,562
Investment, Policy [Policy Text Block]	Investments In June 2022, June 30, 2022, 10 We consider all highly liquid debt investments with original maturities from the date of purchase of three 3 Our investments in debt securities consist of Unites States (US) Treasury securities, including Notes, Bonds, and Bills, and US Government Agency securities, that are designated as held-to-maturity (HTM) and stated at amortized cost. The Company has the positive intent and ability to hold these investments to maturity and does not three three one one
Inventory, Policy [Policy Text Block]	Inventories Inventories consist primarily of equipment constructed for resale and spare parts and are stated at the lower of cost or net realizable value, using the weighted-average cost method. At June 30, 2022 and December 31, 2021 , inventory included equipment constructed for resale of $ and $ , respectively, and spare parts, net of reserves of $ and $ , respectively. Usage is recorded in cost of sales in the period that parts were issued to a project, used to service equipment, or sold to customers. In not

Note 2 - Summary of Significa_2

Note 2 - Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2022
Notes Tables
Schedule of Cash and Cash Equivalents [Table Text Block]	June 30, June 30, 2022 2021 Cash $ 23,298 $ 36,194 Cash equivalents 8,010 — Restricted cash and cash equivalents included in current assets 1,990 98 Restricted cash included in long-term assets — 270 Total cash, cash equivalents, and restricted cash and cash equivalents shown in the Condensed Consolidated Statements of Cash Flows $ 33,298 $ 36,562

Note 3 - Revenue (Tables)

Note 3 - Revenue (Tables)	6 Months Ended
	Jun. 30, 2022
Notes Tables
Disaggregation of Revenue [Table Text Block]	Three Months Ended Six Months Ended June 30, June 30, 2022 2021 2022 2021 Air Pollution Control Technology solutions $ 1,966 $ 223 $ 3,807 $ 596 Spare parts 262 236 358 416 Ancillary revenue 510 527 777 881 Total Air Pollution Control technology revenues 2,738 986 4,942 1,893 FUEL CHEM FUEL CHEM technology solutions 3,630 4,232 6,961 8,358 Total Revenues $ 6,368 $ 5,218 $ 11,903 $ 10,251
Revenue from External Customers by Geographic Areas [Table Text Block]	Three Months Ended Six Months Ended June 30, June 30, 2022 2021 2022 2021 United States $ 4,279 $ 4,588 $ 7,967 $ 9,051 Foreign Revenues Latin America 60 142 129 217 Europe 922 301 1,326 676 Asia 1,107 187 2,481 307 Total Foreign Revenues 2,089 630 3,936 1,200 Total Revenues $ 6,368 $ 5,218 $ 11,903 $ 10,251
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block]	Three Months Ended Six Months Ended June 30, June 30, 2022 2021 2022 2021 Products transferred at a point in time $ 4,402 $ 4,995 $ 8,096 $ 9,655 Products and services transferred over time 1,966 223 3,807 596 Total Revenues $ 6,368 $ 5,218 $ 11,903 $ 10,251
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]	As of June 30, 2022 December 31, 2021 Trade receivables $ 5,500 $ 2,122 Unbilled receivables 1,106 1,277 Other short-term receivables 78 83 Allowance for doubtful accounts (260 ) (223 ) Total accounts receivable $ 6,424 $ 3,259

Note 4 - Restructuring Activi_2

Note 4 - Restructuring Activities (Tables)	6 Months Ended
	Jun. 30, 2022
Notes Tables
Restructuring and Related Costs [Table Text Block]	Three Months Ended Six Months Ended June 30, June 30, 2022 2021 2022 2021 Total revenues $ — $ 4 $ 1 $ 15 Net loss (38 ) (63 ) (51 ) (38 ) As of June 30, 2022 December 31, 2021 Total assets $ 1,121 $ 1,235 Total liabilities 85 92 Total net assets $ 1,036 $ 1,143

Note 5 - Accumulated Other Co_2

Note 5 - Accumulated Other Comprehensive Loss (Tables)	6 Months Ended
	Jun. 30, 2022
Notes Tables
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	Three Months Ended Six Months Ended June 30, June 30, 2022 2021 2022 2021 Foreign currency translation Balance at beginning of period $ (1,674 ) $ (1,563 ) $ (1,604 ) $ (1,370 ) Other comprehensive (loss) income: Foreign currency translation adjustments (1) (222 ) 133 (292 ) (60 ) Total accumulated other comprehensive loss $ (1,896 ) $ (1,430 ) $ (1,896 ) $ (1,430 )

Note 7 - Earnings Per Share (Ta

Note 7 - Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2022
Notes Tables
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	Three Months Ended Six Months Ended June 30, June 30, 2022 2021 2022 2021 Basic weighted-average shares 30,296,000 30,264,000 30,282,000 28,895,000 Conversion of unsecured loan notes — — — — Unexercised options and unvested RSUs — — — — Diluted weighted-average shares 30,296,000 30,264,000 30,282,000 28,895,000

Note 8 - Stock-based Compensa_2

Note 8 - Stock-based Compensation (Tables)	6 Months Ended
	Jun. 30, 2022
Notes Tables
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]	Three Months Ended Six Months Ended June 30, June 30, 2022 2021 2022 2021 Stock options and restricted stock units, net of forfeitures $ 28 $ 20 $ 46 $ 40 After-tax effect of stock-based compensation $ 28 $ 20 $ 46 $ 40
Share-Based Payment Arrangement, Option, Activity [Table Text Block]	Weighted- Average Number Weighted- Remaining Aggregate of Average Contractual Intrinsic Options Exercise Price Term Value Outstanding on January 1, 2022 434,500 $ 3.05 Granted — — Exercised — — Expired or forfeited (50,000 ) 3.55 Outstanding on June 30, 2022 384,500 $ 2.98 2.94 $ 24 Exercisable on June 30, 2022 384,500 $ 2.98 2.94 $ 24
Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]	Weighted Average Grant Date Shares Fair Value Unvested restricted stock units at January 1, 2022 45,003 $ 1.51 Granted 807,048 1.32 Forfeited — — Vested (45,003 ) 1.51 Unvested restricted stock units at June 30, 2022 807,048 $ 1.32

Note 9 - Warrants (Tables)

Note 9 - Warrants (Tables)	6 Months Ended
	Jun. 30, 2022
Notes Tables
Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]	Range of Exercise Price Number Outstanding/Exercisable Weighted Average Remaining Life in Years Weighted Average Exercise Price $5.10 2,500,000 4.12 $ 5.10 $6.45 350,000 4.12 $ 6.45 2,850,000

Note 11 - Business Segment an_2

Note 11 - Business Segment and Geographic Financial Data (Tables)	6 Months Ended
	Jun. 30, 2022
Notes Tables
Schedule of Segment Reporting Information, by Segment [Table Text Block]	Air Pollution FUEL CHEM Three months ended June 30, 2022 Control Segment Segment Other Total Revenues from external customers $ 2,738 $ 3,630 $ — $ 6,368 Cost of sales (1,802 ) (1,888 ) — (3,690 ) Gross margin 936 1,742 — 2,678 Selling, general and administrative — — (2,874 ) (2,874 ) Research and development — — (289 ) (289 ) Operating income (loss) from operations $ 936 $ 1,742 $ (3,163 ) $ (485 ) Air Pollution FUEL CHEM Three months ended June 30, 2021 Control Segment Segment Other Total Revenues from external customers $ 986 $ 4,232 $ — $ 5,218 Cost of sales (507 ) (2,128 ) — (2,635 ) Gross margin 479 2,104 — 2,583 Selling, general and administrative — — (2,957 ) (2,957 ) Research and development — — (315 ) (315 ) Operating income (loss) from operations $ 479 $ 2,104 $ (3,272 ) $ (689 ) Air Pollution FUEL CHEM Six months ended June 30, 2022 Control Segment Segment Other Total Revenues from external customers $ 4,942 $ 6,961 $ — $ 11,903 Cost of sales (3,231 ) (3,704 ) — (6,935 ) Gross margin 1,711 3,257 — 4,968 Selling, general and administrative — — (5,928 ) (5,928 ) Research and development — — (509 ) (509 ) Operating income (loss) from operations $ 1,711 $ 3,257 $ (6,437 ) $ (1,469 ) Air Pollution FUEL CHEM Six months ended June 30, 2021 Control Segment Segment Other Total Revenues from external customers $ 1,893 $ 8,358 $ — $ 10,251 Cost of sales (1,038 ) (4,272 ) — (5,310 ) Gross margin 855 4,086 — 4,941 Selling, general and administrative — — (6,057 ) (6,057 ) Research and development — — (730 ) (730 ) Operating income (loss) from operations $ 855 $ 4,086 $ (6,787 ) $ (1,846 )
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block]	Three Months Ended Six Months Ended June 30, June 30, 2022 2021 2022 2021 Revenues: United States $ 4,279 $ 4,588 $ 7,967 $ 9,051 Foreign 2,089 630 3,936 1,200 $ 6,368 $ 5,218 $ 11,903 $ 10,251 June 30, December 31, 2022 2021 Assets: United States $ 45,934 $ 46,271 Foreign 3,184 3,703 $ 49,118 $ 49,974

Note 12 - Accrued Liabilities (

Note 12 - Accrued Liabilities (Tables)	6 Months Ended
	Jun. 30, 2022
Notes Tables
Other Current Liabilities [Table Text Block]	As of June 30, 2022 December 31, 2021 Contract liabilities (Note 3) $ 578 $ 390 Other accrued liabilities 309 471 Total other accrued liabilities $ 887 $ 861

Note 2 - Summary of Significa_3

Note 2 - Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Restricted Cash and Cash Equivalents, Total	$ 1,990
Investment Plan, Maximum Amount. Approved	10,000
Inventory, Net, Total	405	$ 348
Equipment Contstructed for Resale [Member]
Inventory, Net, Total	208	227
Spare Parts [Member]
Inventory, Net, Total	$ 197	$ 121
Minimum [Member]
Debt Securities, Held-to-maturity, Maturity Term (Month)	3 months
Maximum [Member]
Debt Securities, Held-to-maturity, Maturity Term (Month)	36 months
Money Market Funds [Member]
Restricted Cash and Investments, Total	$ 10,000

Note 2 - Summary of Significa_4

Note 2 - Summary of Significant Accounting Policies - Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Cash	$ 23,298		$ 36,194
Cash equivalents	8,010		0
Restricted cash and cash equivalents included in current assets	1,990	$ 891	98
Restricted cash included in long-term assets	0	$ 270	270
Total cash, cash equivalents, and restricted cash and cash equivalents shown in the Condensed Consolidated Statements of Cash Flows	$ 33,298		$ 36,562

Note 3 - Revenue 1 (Details Tex

Note 3 - Revenue 1 (Details Textual) Pure in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Contract with Customer, Liability, Current	$ 578		$ 578		$ 390	$ 850
Contract with Customer, Liability, Revenue Recognized	$ 20	$ 49	$ 250	$ 157
Contract with Customer, Contracts in Progress, Number of Contracts Identified as Loss Contracts	0		0		0
Revenue, Remaining Performance Obligation, Amount	$ 10,547		$ 10,547
Air Pollution Control [Member]
Contract with Customer, Asset, after Allowance for Credit Loss, Total	1,106		1,106		$ 1,277	2,079
FUEL CHEM [Member]
Contract with Customer, Asset, after Allowance for Credit Loss, Total	$ 0		$ 0		$ 0	$ 269

Note 3 - Revenue 2 (Details Tex

Note 3 - Revenue 2 (Details Textual) $ in Thousands	Jun. 30, 2022 USD ($)
Revenue, Remaining Performance Obligation, Amount	$ 10,547
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01
Revenue, Remaining Performance Obligation, Amount	$ 8,414
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period (Month)	12 months

Note 3 - Revenue - Revenues Dis

Note 3 - Revenue - Revenues Disaggregated by Product Technology (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenues	$ 6,368	$ 5,218	$ 11,903	$ 10,251
Air Pollution Control [Member]
Revenues	2,738	986	4,942	1,893
Air Pollution Control [Member] | Technology Solutions [Member]
Revenues	1,966	223	3,807	596
Air Pollution Control [Member] | Spare Parts [Member]
Revenues	262	236	358	416
Air Pollution Control [Member] | Ancillary Revenue [Member]
Revenues	510	527	777	881
FUEL CHEM [Member]
Revenues	3,630	4,232	6,961	8,358
FUEL CHEM [Member] | Technology Solutions [Member]
Revenues	$ 3,630	$ 4,232	$ 6,961	$ 8,358

Note 3 - Revenue - Revenues D_2

Note 3 - Revenue - Revenues Disaggregated by Geography (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenues	$ 6,368	$ 5,218	$ 11,903	$ 10,251
UNITED STATES
Revenues	4,279	4,588	7,967	9,051
Latin America [Member]
Revenues	60	142	129	217
Europe [Member]
Revenues	922	301	1,326	676
Asia [Member]
Revenues	1,107	187	2,481	307
Non-US [Member]
Revenues	$ 2,089	$ 630	$ 3,936	$ 1,200

Note 3 - Revenue - Timing of Re

Note 3 - Revenue - Timing of Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenues	$ 6,368	$ 5,218	$ 11,903	$ 10,251
Transferred at Point in Time [Member]
Revenues	4,402	4,995	8,096	9,655
Transferred over Time [Member]
Revenues	$ 1,966	$ 223	$ 3,807	$ 596

Note 3 - Revenue - Components o

Note 3 - Revenue - Components of Accounts Receivable (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Trade receivables	$ 5,500	$ 2,122
Unbilled receivables	1,106	1,277
Other short-term receivables	78	83
Allowance for doubtful accounts	(260)	(223)
Total accounts receivable	$ 6,424	$ 3,259

Note 4 - Restructuring Activi_3

Note 4 - Restructuring Activities - Charges and Net Assets (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Revenues	$ 6,368		$ 5,218		$ 11,903	$ 10,251
Net loss	(356)	$ (998)	(778)	$ 398	(1,354)	(380)
Total assets	49,118				49,118		$ 49,974
Total liabilities	4,535				4,535		3,774
CHINA
Revenues	0		4		1	15
Net loss	(38)		$ (63)		(51)	$ (38)
Total assets	1,121				1,121		1,235
Total liabilities	85				85		92
Total net assets	$ 1,036				$ 1,036		$ 1,143

Note 5 - Accumulated Other Co_3

Note 5 - Accumulated Other Comprehensive Loss - Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Balance		$ 45,133	$ 46,523	$ 46,200	$ 22,321
Balance		44,583	45,898	44,583	45,898
AOCI Attributable to Parent [Member]
Balance		(1,674)	(1,563)	(1,604)	(1,370)
Foreign currency translation adjustments (1)	[1]	(222)	133	(292)	(60)
Balance		$ (1,896)	$ (1,430)	$ (1,896)	$ (1,430)
[1]In all periods presented, there were no tax impacts related to rate changes and no amounts were reclassified to earnings.

Note 6 - Treasury Stock (Detail

Note 6 - Treasury Stock (Details Textual) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Treasury Stock, Shares, Total (in shares)	976,006	963,509
Treasury Stock, Value, Total	$ 2,251	$ 2,234

Note 7 - Earnings Per Share (De

Note 7 - Earnings Per Share (Details Textual) - shares	3 Months Ended	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2022	Jun. 30, 2021
Weighted Average Equity Awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)	583,000	466,000	160,000
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)	2,850,000	2,850,000
Incremental Equity Awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)	23,000	36,000

Note 7 - Earnings Per Share - E

Note 7 - Earnings Per Share - Earnings Per Share (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Basic weighted-average shares (in shares)	30,296,000	30,264,000	30,282,000	28,895,000
Conversion of unsecured loan notes (in shares)	0	0	0	0
Unexercised options and unvested RSUs (in shares)	0	0	0	0
Diluted weighted-average shares (in shares)	30,296,000	30,264,000	30,282,000	28,895,000

Note 8 - Stock-based Compensa_3

Note 8 - Stock-based Compensation (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)			0
Deferred Compensation Plan for Directors [Member]
Deferred Compensation Arrangement with Individual, Compensation Expense			$ 0	$ 0
The 2014 Long-term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)	5,600,676		5,600,676
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)	1,809,250		1,809,250
Share-Based Payment Arrangement, Expense, Tax Benefit	$ 0	$ 0	$ 0	$ 0
The 2014 Long-term Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)			10 years
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)			0
The 2014 Long-term Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member] | Share-Based Payment Arrangement, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			50%
The 2014 Long-term Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member] | Share-Based Payment Arrangement, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			25%
The 2014 Long-term Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member] | Share-Based Payment Arrangement, Tranche Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			25%
The 2014 Long-term Incentive Plan [Member] | Restricted Stock Units (RSUs) [Member]
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	$ 916		$ 916
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)			2 years 9 months 18 days
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value			$ 68
The 2014 Long-term Incentive Plan [Member] | Restricted Stock Units (RSUs) [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)			2 years
The 2014 Long-term Incentive Plan [Member] | Restricted Stock Units (RSUs) [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)			4 years

Note 8 - Stock-based Compensa_4

Note 8 - Stock-based Compensation - Stock-based Compensation (Details) - Selling, General and Administrative Expenses [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Stock options and restricted stock units, net of forfeitures	$ 28	$ 20	$ 46	$ 40
After-tax effect of stock-based compensation	$ 28	$ 20	$ 46	$ 40

Note 8 - Stock-based Compensa_5

Note 8 - Stock-based Compensation - Stock Option Activity (Details) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2022 USD ($) $ / shares shares
Beginning balance, number of options outstanding (in shares) | shares	434,500
Beginning balance, option, weighted average exercise price (in dollars per share) | $ / shares	$ 3.05
Granted, options (in shares) | shares	0
Granted, option, weighted average exercise price (in dollars per share) | $ / shares	$ 0
Exercised, options (in shares) | shares	0
Exercised, option, weighted average exercise price (in dollars per share) | $ / shares	$ 0
Expired or forfeited, options (in shares) | shares	(50,000)
Expired or forfeited, option, weighted average exercise price (in dollars per share) | $ / shares	$ 3.55
Ending balance, number of options outstanding (in shares) | shares	384,500
Ending balance, option, weighted average exercise price (in dollars per share) | $ / shares	$ 2.98
Outstanding, weighted average remaining contractual term (Year)	2 years 11 months 8 days
Outstanding, aggregate intrinsic value | $	$ 24
Exercisable, options (in shares) | shares	384,500
Exercisable, option, weighted average exercise price (in dollars per share) | $ / shares	$ 2.98
Exercisable, weighted average remaining contractual term (Year)	2 years 11 months 8 days
Exercisable, aggregate intrinsic value | $	$ 24

Note 8 - Stock-based Compensa_6

Note 8 - Stock-based Compensation - Restricted Stock Activity (Details) - Restricted Stock Units (RSUs) [Member]	6 Months Ended
	Jun. 30, 2022 $ / shares shares
Beginning balance, unvested restricted stock units, shares (in shares) | shares	45,003
Beginning balance, unvested restricted stock units, weighted average grant date fair value (in dollars per share) | $ / shares	$ 1.51
Granted, unvested restricted stock units, shares (in shares) | shares	807,048
Granted, unvested restricted stock units, weighted average grant date fair value (in dollars per share) | $ / shares	$ 1.32
Forfeited, restricted stock units, shares (in shares) | shares	0
Forfeited, restricted stock units, weighted average grant date fair value (in dollars per share) | $ / shares	$ 0
Vested, restricted stock units, shares (in shares) | shares	(45,003)
Vested, restricted stock units, weighted average grant date fair value (in dollars per share) | $ / shares	$ 1.51
Ending balance, unvested restricted stock units, shares (in shares) | shares	807,048
Ending balance, unvested restricted stock units, weighted average grant date fair value (in dollars per share) | $ / shares	$ 1.32

Note 9 - Warrants - Summary of

Note 9 - Warrants - Summary of Warrants Outstanding and Exercisable (Details)	6 Months Ended
	Jun. 30, 2022 $ / shares shares
Number outstanding/ exercisable (in shares)	2,850,000
Warrants Issued in Connection with Private Placement [Member]
Number outstanding/ exercisable (in shares)	2,500,000
Weighted average remaining life (Year)	4 years 1 month 13 days
Weighted average exercise price (in dollars per share) | $ / shares	$ 5.10
The Placement Agent Warrants [Member]
Number outstanding/ exercisable (in shares)	350,000
Weighted average remaining life (Year)	4 years 1 month 13 days
Weighted average exercise price (in dollars per share) | $ / shares	$ 6.45

Note 10 - Debt Financing (Detai

Note 10 - Debt Financing (Details Textual) - USD ($) $ in Thousands	Jun. 30, 2022	Jan. 08, 2021	Apr. 17, 2020
Percentage of Face Amount of Letters of Credit As Collateral	150%
Payment, Basis Points on Face Value of Letters of Credit	2.50%
Letters of Credit Outstanding, Amount	$ 1,326
Paycheck Protection Program CARES Act [Member]
Proceeds from Issuance of Long-term Debt, Total			$ 1,556
Debt Instrument, Decrease, Forgiveness		$ 1,556
Asset Pledged as Collateral [Member]
Investments, Total	$ 1,990

Note 11 - Business Segment an_3

Note 11 - Business Segment and Geographic Financial Data (Details Textual)	6 Months Ended
	Jun. 30, 2022
Number of Reportable Segments	2

Note 11 - Business Segment an_4

Note 11 - Business Segment and Geographic Financial Data - Reporting Segment Net Sales and Gross Margin (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenues from external customers	$ 6,368	$ 5,218	$ 11,903	$ 10,251
Cost of sales	(3,690)	(2,635)	(6,935)	(5,310)
Gross margin	2,678	2,583	4,968	4,941
Selling, general and administrative	(2,874)	(2,957)	(5,928)	(6,057)
Research and development	(289)	(315)	(509)	(730)
Operating income (loss) from operations	(485)	(689)	(1,469)	(1,846)
Air Pollution Control [Member]
Revenues from external customers	2,738	986	4,942	1,893
Cost of sales	(1,802)	(507)	(3,231)	(1,038)
Gross margin	936	479	1,711	855
Selling, general and administrative	0	0	0	0
Research and development	0	0	0	0
Operating income (loss) from operations	936	479	1,711	855
FUEL CHEM [Member]
Revenues from external customers	3,630	4,232	6,961	8,358
Cost of sales	(1,888)	(2,128)	(3,704)	(4,272)
Gross margin	1,742	2,104	3,257	4,086
Selling, general and administrative	0	0	0	0
Research and development	0	0	0	0
Operating income (loss) from operations	1,742	2,104	3,257	4,086
Other Segments [Member]
Revenues from external customers	0	0	0	0
Cost of sales	0	0	0	0
Gross margin	0	0	0	0
Selling, general and administrative	(2,874)	(2,957)	(5,928)	(6,057)
Research and development	(289)	(315)	(509)	(730)
Operating income (loss) from operations	$ (3,163)	$ (3,272)	$ (6,437)	$ (6,787)

Note 11 - Business Segment an_5

Note 11 - Business Segment and Geographic Financial Data - Geographic Segment Financial Data (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Revenues	$ 6,368	$ 5,218	$ 11,903	$ 10,251
Assets	49,118		49,118		$ 49,974
UNITED STATES
Revenues	4,279	4,588	7,967	9,051
Assets	45,934		45,934		46,271
Non-US [Member]
Revenues	2,089	$ 630	3,936	$ 1,200
Assets	$ 3,184		$ 3,184		$ 3,703

Note 12 - Accrued Liabilities -

Note 12 - Accrued Liabilities - Components of Other Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021	Dec. 31, 2020
Contract liabilities (Note 3)	$ 578	$ 390	$ 850
Other accrued liabilities	309	471
Total other accrued liabilities	$ 887	$ 861

Note 13 - Commitments and Con_2

Note 13 - Commitments and Contingencies (Details Textual) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Standard Product Warranty Accrual, Period Increase (Decrease), Total	$ 0	$ 0
Standard Product Warranty Accrual, Ending Balance	$ 159		$ 159

Note 14 - Income Taxes (Details

Note 14 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Effective Income Tax Rate Reconciliation, Percent, Total		0.70%	2.60%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21%	21%
Unrecognized Tax Benefits, Ending Balance	$ 0	$ 0		$ 0