ClearSign Reports Successful Sub 5ppm Department of Energy/Small Business Innovation Research Flexible Fuel Burner Testing

Rhea-AI Summary

ClearSign (Nasdaq:CLIR) announced successful DOE/NETL SBIR Phase II testing of its ClearSign Core 2 flexible-fuel burner on March 11, 2026. The 2.5-year program demonstrated sub-5 ppm NOx across fuel blends including 100% hydrogen at a 8 million BTU/hr scale and advances toward commercial field installations following a $1.65 million award.

Positive

• Demonstrated NOx 5 ppm
• $1.65 million DOE SBIR Phase II funding supported development
• Burner scaled and tested at 8 million BTU/hr capacity
• Designed for 100% hydrogen capability and easy retrofit into existing heaters

Negative

• None.

News Market Reaction – CLIR

-21.65% 5.0x vol

13 alerts

-21.65% News Effect

-13.6% Trough in 8 hr 16 min

-$8M Valuation Impact

$31M Market Cap

5.0x Rel. Volume

On the day this news was published, CLIR declined 21.65%, reflecting a significant negative market reaction. Argus tracked a trough of -13.6% from its starting point during tracking. Our momentum scanner triggered 13 alerts that day, indicating notable trading interest and price volatility. This price movement removed approximately $8M from the company's valuation, bringing the market cap to $31M at that time. Trading volume was very high at 5.0x the daily average, suggesting heavy selling pressure.

Data tracked by StockTitan Argus on the day of publication.

Key Figures

NOx emissions: <5 ppm Burner capacity: 8 million BTU/hour Hydrogen capability: 100% hydrogen +5 more

8 metrics

NOx emissions <5 ppm ClearSign Core 2 burner performance across full fuel blend range

Burner capacity 8 million BTU/hour Scaled ClearSign Core burner used in testing

Hydrogen capability 100% hydrogen Flexible fuel burner supports pure hydrogen and blends

Project duration 2.5 years Flexible Fuel Ultra-Low NOx Process Burner development effort

SBIR Phase II award $1.65 million DOE funding supporting burner development and testing

NOx limit context Sub 5 ppm Targeted ultra-low NOx emission threshold in testing

Fuel range Hydrogen to natural gas Performance across 100% hydrogen, natural gas and intermediate blends

SBIR phase Phase II Stage of DOE Small Business Innovation Research award

Market Reality Check

Price: $0.4474 Vol: Volume 497,799 is 4.83x t...

high vol

$0.4474 Last Close

Volume Volume 497,799 is 4.83x the 20-day average of 103,113, signaling elevated interest ahead of and around this announcement. high

Technical Shares at 0.571 trade 49.02% below the 52-week high of 1.12 and 24.4% above the 52-week low of 0.459, remaining below the 200-day MA at 0.67 despite today’s gain of 6.51%.

Peers on Argus

CLIR gained 6.51% while close peers showed mixed moves: LIQT up 0.69%, ZONE up 7...

1 Up 1 Down

CLIR gained 6.51% while close peers showed mixed moves: LIQT up 0.69%, ZONE up 7.61%, but TOMZ, CLWT and DEVS down between roughly 2–5%. Momentum scanner data also shows peers moving in both directions, indicating today’s move appears stock-specific rather than a broad sector rotation.

Historical Context

5 past events · Latest: Feb 18 (Neutral)

Pattern 5 events

Date	Event	Sentiment	Move	Catalyst
Feb 18	Corporate update call	Neutral	-3.4%	Announcement of a business update conference call and webcast logistics.
Feb 17	Commercial order win	Positive	+2.3%	Engineering order for a fifth low-emission retrofit enclosed flare system in California.
Jan 07	Preliminary earnings	Positive	+27.9%	Preliminary 2025 results with record Q4 revenue of ≈<b>$3.6M</b> and FY revenue of ≈<b>$5.2M</b>.
Nov 19	Operational update	Positive	-4.5%	Q3 2025 operational update highlighting multiple burner and engineering orders and 100% hydrogen testing.
Nov 06	Earnings call notice	Neutral	-2.2%	Announcement of timing and access details for the Q3 2025 conference call.

Pattern Detected

Operational wins and strong revenue updates have often coincided with positive moves, while some general updates and calls have seen modest negative reactions.

Recent Company History

Over the past six months, CLIR has issued several operational and financial updates. A preliminary 2025 revenue update on Jan 7, 2026 projecting record $3.6M Q4 and $5.2M full-year revenue saw a 27.85% rise. Order wins, such as the fifth low-emission flare order on Feb 17, 2026, also coincided with gains. In contrast, general business and quarter update calls on Nov 6, 2025, Nov 19, 2025, and Feb 18, 2026 produced mild declines. Today’s successful DOE/NETL burner testing fits the pattern of positive, commercially relevant technical milestones.

Market Pulse Summary

The stock dropped -21.6% in the session following this news. A negative reaction despite successful ...

Analysis

The stock dropped -21.6% in the session following this news. A negative reaction despite successful sub-5 ppm NOx testing would contrast with prior strong responses to clear commercial or financial progress, such as the 27.85% move on preliminary 2025 revenue. Historically, more generic update or call announcements saw modest declines, while execution-oriented news skewed positive. Given the stock’s position below the 200-day MA at 0.67 and far under the 52-week high, technical overhangs could still dominate trading even on favorable developments.

Key Terms

small business innovation research, parts per million, internally induced flue gas recirculation, fuel-lean premixing, +4 more

8 terms

small business innovation research regulatory

"under its Small Business Innovation Research ("SBIR") program, it has successfully"

A U.S. government program that gives competitive grants or contracts to small companies to fund early-stage research and development of new technologies and products. For investors, it matters because this non-dilutive funding de-risks research, validates technical progress through staged awards, and can help a small company reach milestones that increase its value without immediate equity dilution—think of it as government seed money that helps a startup prove an idea.

parts per million technical

"achieved NOx emissions that are consistently below 5 parts per million ("ppm")"

Parts per million (ppm) is a way to express a very small concentration: one unit of something for every one million units of the whole, like one drop in an Olympic-size pool. Investors encounter ppm when companies report pollutant levels, chemical residues, or trace impurities in products and supply chains; small numerical differences can trigger regulatory limits, cleanup costs, or safety concerns that affect a company’s expenses, reputation, and legal risk.

internally induced flue gas recirculation technical

"This is accomplished through integrated features such as internally induced flue gas recirculation, fuel-lean"

A combustion design technique that reroutes a portion of hot exhaust gases back into the burner chamber so the flame runs cooler and more evenly, reducing formation of pollutants like nitrogen oxides and improving fuel use. For investors, it matters because it can lower emissions-control costs, help plants meet regulatory limits, and improve operating efficiency—affecting capital spending, ongoing operating expenses, and regulatory risk for energy and industrial companies.

fuel-lean premixing technical

"internally induced flue gas recirculation, fuel-lean premixing and a patented distal flameholder"

Fuel-lean premixing is a combustion approach where fuel is blended with more air than needed before ignition so the burned mixture is 'lean' (less fuel per unit of air). Like diluting a strong sauce so it burns less, this technique typically lowers harmful emissions and can improve fuel efficiency for engines and turbines. Investors watch it because it affects operating costs, regulatory compliance and product competitiveness in energy, industrial and transportation markets.

distal flameholder technical

"fuel-lean premixing and a patented distal flameholder, all contained within a compact"

A distal flameholder is a small internal device placed downstream inside a burner or jet engine combustor that helps a flame stay anchored and burn steadily under fast-moving air. Think of it like a rock in a fast stream that creates a calm pocket where a candle can keep burning; without it the flame can blow out or burn unevenly. For investors, its design and condition affect fuel efficiency, emissions, safety, maintenance costs and regulatory compliance for companies that make or use combustion equipment.

selective catalytic reduction technical

"without needing additional post-combustion controls like selective catalytic reduction or diluents."

Selective catalytic reduction is an emissions control system fitted to diesel engines that injects a harmless liquid reagent and passes exhaust through a catalyst to convert nitrogen oxides into nitrogen and water. Think of it as a chemical “cleaning step” added to an engine’s exhaust pipe. Investors care because regulations and enforcement drive demand for these systems and their consumables, affect manufacturing costs, create aftermarket service needs, and can influence fines or compliance expenditures for vehicle makers and fleet operators.

hydrocarbon technical

"the full gamut of petrochemical and refinery hydrocarbon fuel gas blends, and natural gas"

Hydrocarbon is a molecule made only of hydrogen and carbon atoms that forms the basis of fuels like oil, gasoline and natural gas as well as many industrial chemicals. Think of hydrocarbons as the raw energy “logs” and building blocks the economy burns or transforms into products; their abundance, quality and price directly affect company revenues, exploration value and investment risk, including exposure to regulatory and environmental costs.

british thermal units technical

"The ClearSign Core burner, scaled to 8 million British thermal units per hour, has demonstrated"

A British thermal unit (BTU) is a standard measure of heat energy, defined as the amount of heat needed to raise one pound of water by one degree Fahrenheit; think of it as the calorie of the energy world. Investors use BTUs to compare the energy content and efficiency of fuels, heating systems and power generation, which affects commodity pricing, contract volumes and the economics of energy-related companies and infrastructure.

AI-generated analysis. Not financial advice.

Partnered with National Energy Technology Laboratory to Advance Flexible Fuel, Ultra-Low NOx Combustion for Industrial Operations

TULSA, OK / ACCESS Newswire / March 11, 2026 / ClearSign Technologies Corporation (Nasdaq:CLIR) ("ClearSign" or the "Company"), a leader in advanced combustion and sensing technologies that help industrial operators dramatically reduce emissions, increase efficiency and safety, and support the use of cleaner fuels including hydrogen, announces today that, in conjunction with the U.S. Department of Energy's ("DOE") National Energy Technology Laboratory ("NETL"), under its Small Business Innovation Research ("SBIR") program, it has successfully completed the testing of its ClearSign Core^™ Flexible Fuel, 100% Hydrogen Capable process burner branded as ClearSign Core^™ 2.

"We are very pleased to publicly report the success of this flexible fuel burner development project," said Jim Deller, Ph.D., Chief Executive Officer of ClearSign. "We are thankful for the SBIR program funding that allowed us to develop and demonstrate a technology designed to meet the real-world needs of U.S. refineries and chemical processing facilities. This technology enables compliant and cost-effective use of fuels ranging from 100% hydrogen, the full gamut of petrochemical and refinery hydrocarbon fuel gas blends, and natural gas in industrial heating operations. We believe that these ultra-low NOx results and ease of use are unmatched by any other burner that we know of in the market."

Many industrial operators in these industries currently have access to a variety of opportunity fuels or specific gas compositions that traditionally require extremely costly heater modifications to meet regulatory nitrogen oxide ("NOx") emission limits in place to help protect air quality and respiratory health.

ClearSign's "Flexible Fuel Ultra-Low NOx Process Burner" project, which is nearing its scheduled completion and marking a significant 2.5-year effort, resolves this issue by facilitating fuel flexibility without compromising emissions compliance with the simple replacement of burner technology. This innovative technology allows industrial facilities to enhance operational flexibility, reduce costs associated with fuel procurement and regulatory emissions compliance, and reduce disruptions to operations - all of which may provide Americans with more affordable energy.

The ClearSign Core burner, scaled to 8 million British thermal units per hour, has demonstrated consistent performance across a range of fuel compositions, including 100% hydrogen, natural gas and various intermediate blends. This technology has also achieved NOx emissions that are consistently below 5 parts per million ("ppm") across this entire range of fuel gas blends. This is accomplished through integrated features such as internally induced flue gas recirculation, fuel-lean premixing and a patented distal flameholder, all contained within a compact burner head designed for easy retrofitting into existing heater infrastructure.

"NETL's investment in ClearSign's technology is opening up significant operational advantages for the industry," said Drew O'Connell, NETL federal project manager. "This solution allows companies to effectively utilize a broader spectrum of available fuels, ensuring they operate within permitted NOx limits without needing additional post-combustion controls like selective catalytic reduction or diluents."

This project, which was made possible through a $1.65 million SBIR Phase II award from the DOE, is now progressing to the next stage to implement commercial field installations at operational industrial sites.

ClearSign expects that this advancement will significantly improve operational resilience and competitiveness within the domestic refining and chemical production sectors, aligning with NETL's commitment to providing technological solutions for U.S. industrial needs, increasing industry partnerships and advancing hydrocarbon technologies.

This initiative underscores the impact of DOE's SBIR program, which NETL helps administer, by empowering small businesses, such as Tulsa-based ClearSign, to develop technologies that are expected to address national industrial challenges and strengthen U.S. manufacturing innovation.

NETL is a DOE national laboratory dedicated to innovating and accelerating the nation's energy solutions in hydrocarbon, geothermal energy and critical minerals production. With research sites in Albany, Oregon; Morgantown, West Virginia; and Pittsburgh, Pennsylvania, NETL operates as one laboratory to create advanced energy technologies that support DOE's mission and enable affordable, reliable and secure energy to fuel human prosperity.

About ClearSign Technologies Corporation

ClearSign Technologies Corporation designs and develops products and technologies for the purpose of decarbonization and improving key performance characteristics of industrial and commercial systems, including operational performance, energy efficiency, emission reduction, safety, the use of hydrogen as a fuel and overall cost-effectiveness. Our patented technologies, embedded in established OEM products as ClearSign Core^™ and ClearSign Eye^™ and other sensing configurations, enhance the performance of combustion systems and fuel safety systems in a broad range of markets, including the energy (upstream oil production and down-stream refining), commercial/industrial boiler, chemical, petrochemical, transport and power industries. For more information, please visit www.clearsign.com.

For further information:

Investor Relations:

Matthew Selinger
Firm IR Group for ClearSign
+1 415-572-8152
mselinger@firmirgroup.com

Cautionary note on forward-looking statements

All statements in this press release that are not based on historical fact are "forward-looking statements." You can find many (but not all) of these statements by looking for words such as "approximates," "believes," "hopes," "expects," "anticipates," "estimates," "projects," "intends," "plans," "would," "should," "could," "may," "will" or other similar expressions. While management has based any forward-looking statements included in this press release on its current expectations on the Company's strategy, plans, intentions, performance, or future occurrences or results, the information on which such expectations were based may change. These forward-looking statements rely on a number of assumptions concerning future events and are subject to a number of risks, uncertainties and other factors, many of which are outside of the Company's control, that could cause actual results to materially differ from such statements. Such risks, uncertainties and other factors include, but are not limited to, the Company's ability to successfully complete engineering orders for its customers; the Company's ability to generate equipment and installation orders following an initial engineering order from customers; the Company's ability to successfully deliver, install, and meet the performance obligations of the Company's burners in the California market and any other markets the Company may sell products in; the Company's ability to further expand the sale of ultra-low NOx process, flare and boiler burners; the Company's ability to further validate its burners' performance in commercial applications and complete field installations at operational industrial sites; the Company's ability to, through its technologies, provide increased operational flexibility, cost reductions and uninterrupted operations to its customers; the Company's ability to improve operational resilience and competitiveness within the domestic defining and chemical production sectors; the Company's ability to continue expanding its customer base in the refining industry; the Company's ability to effectively compete in the flare industry and to retain its existing customers in such industry; the Company's ability to provide low emissions retrofit solutions based on continuously changing air permit requirements at the federal and state level; the Company's ability to continue innovating and expanding its scope of product and service applications; the Company's ability to expand its engagement with current and future customers beyond burner technology and into broader emission and system integration solutions; general business and economic conditions; the performance of management and the Company's employees; the Company's ability to obtain financing; whether the Company's technology will be accepted and adopted and other factors identified in the Company's Annual Report on Form 10-K and other periodic and current reports filed with the U.S. Securities and Exchange Commission and available for review at www.sec.gov. Furthermore, the Company operates in a competitive environment where new and unanticipated risks may arise. Accordingly, investors should not place any reliance on forward-looking statements as a prediction of actual results. The Company disclaims any intention to, and, except as may be required by law, undertakes no obligation to, update or revise forward-looking statements to reflect events or circumstances that subsequently occur or of which the Company hereafter become aware.

SOURCE: ClearSign Technologies

View the original press release on ACCESS Newswire

FAQ

What did ClearSign (CLIR) announce on March 11, 2026 about its flexible-fuel burner?

ClearSign announced successful DOE/NETL SBIR Phase II testing of its ClearSign Core 2 flexible-fuel burner. According to ClearSign, tests showed consistent performance including 100% hydrogen capability and NOx below 5 ppm across multiple fuel blends at scale.

How low were NOx emissions in ClearSign's CLIR NETL-funded tests and why does that matter?

The tests produced NOx emissions consistently below 5 ppm, a materially low level for industrial burners. According to ClearSign, this can enable compliance without post-combustion controls, reducing capital and operating costs for refineries and chemical plants.

What funding supported ClearSign's (CLIR) burner development and what is the next step?

ClearSign received a $1.65 million DOE SBIR Phase II award to advance the burner. According to ClearSign, the program is progressing toward commercial field installations at operational industrial sites to validate real-world performance.

What fuel types and operating scale did ClearSign (CLIR) demonstrate with the Core 2 burner?

The Core 2 burner was tested across natural gas, intermediate blends and 100% hydrogen at an 8 million BTU/hr scale. According to ClearSign, the design maintains ultra-low NOx across this full spectrum and is intended for retrofit applications.

How could ClearSign's (CLIR) technology affect industrial operators' ability to use hydrogen and fuel blends?

ClearSign's burner aims to enable cost-effective use of hydrogen and diverse fuel blends without major heater modifications. According to ClearSign, the flexible design reduces emissions compliance risk and may lower costs by avoiding additional post-combustion controls.