| Segment Reporting [Text Block] |
11. 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 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 (ESP) 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® technology segment, which uses chemical processes in combination with advanced Computational Fluid Dynamics and Chemical Kinetics Modeling 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.
Our Chief Executive Officer (CEO) serves as our Chief Operating Decision Maker (CODM) and is responsible for reviewing segment performance and making decisions regarding resource allocation. We evaluate performance and allocate resources based on reviewing gross margin by reportable segment. We do not allocate selling, general and administrative expenses, interest, other non-operating income or expense items, or taxes to segments. 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 is provided below:
| | | Air Pollution | | | FUEL CHEM | | | | | | | | | |
| Three months ended March 31, 2026 | | Control Segment | | | Segment | | | Other | | | Total | |
| Revenues from external customers | | $ | 1,604 | | | $ | 4,476 | | | $ | — | | | $ | 6,080 | |
| Cost of sales | | | (989 | ) | | | (2,447 | ) | | | — | | | | (3,436 | ) |
| Gross margin | | | 615 | | | | 2,029 | | | | — | | | | 2,644 | |
| Selling, general and administrative | | | — | | | | — | | | | (3,716 | ) | | | (3,716 | ) |
| Research and development | | | — | | | | — | | | | (524 | ) | | | (524 | ) |
| Income (loss) from operations | | $ | 615 | | | $ | 2,029 | | | $ | (4,240 | ) | | $ | (1,596 | ) |
| | | Air Pollution | | | FUEL CHEM | | | | | | | | | |
| Three months ended March 31, 2025 | | Control Segment | | | Segment | | | Other | | | Total | |
| Revenues from external customers | | $ | 1,303 | | | $ | 5,079 | | | $ | — | | | $ | 6,382 | |
| Cost of sales | | | (878 | ) | | | (2,545 | ) | | | — | | | | (3,423 | ) |
| Gross margin | | | 425 | | | | 2,534 | | | | — | | | | 2,959 | |
| Selling, general and administrative | | | — | | | | — | | | | (3,341 | ) | | | (3,341 | ) |
| Research and development | | | — | | | | — | | | | (570 | ) | | | (570 | ) |
| Income (loss) from operations | | $ | 425 | | | $ | 2,534 | | | $ | (3,911 | ) | | $ | (952 | ) |
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 | |
| | | March 31, | |
| | | 2026 | | | 2025 | |
| Revenues: | | | | | | | | |
| United States | | $ | 5,247 | | | $ | 5,359 | |
| Foreign | | | 833 | | | | 1,023 | |
| | | $ | 6,080 | | | $ | 6,382 | |
| | | March 31, | | | December 31, | |
| | | 2026 | | | 2025 | |
| Assets: | | | | | | | | |
| United States | | $ | 41,751 | | | $ | 44,345 | |
| Foreign | | | 2,736 | | | | 2,834 | |
| | | $ | 44,487 | | | $ | 47,179 | |
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