Clean energy startup ClearFlame raises $30M in funding to make heavy-duty diesel engines run on renewable fuels

Unknown to many, the transportation sector is the largest domestic contributor to climate change. According to the US Department of Transportation (DOT), the U.S. transportation sector is responsible for more greenhouse gas emissions than any other sector of our economy.

A large portion of this comes from trucks and vehicles with heavy-duty internal combustion engines. In fact, diesel fuel consumption accounts for approximately 26% of overall CO2 emissions from the U.S. transportation sector. It is for this reason that one startup is trying to reverse the trend and make heavy-duty diesel engines run on decarbonized, renewable fuels.

Enter ClearFlame Engine Technologies, a Chicago-based Black- and Women-founded and led startup that has kept the heavy-duty, internal combustion engine and modified it to break free from diesel fuel and run on decarbonized, renewable, liquid fuels already in existence across the globe.  After years of research at Stanford University and Argonne National Laboratory, the ClearFlame team has found the answer: “The diesel engine, without the diesel fuel,” the company said on its website.

While electric powertrains face significant barriers for heavy-duty applications, ClearFlame’s technology offers a solution for heavy-duty applications where electric powertrains encounter significant obstacles. It can fulfill the requirements for heavy-duty performance and reduce lifecycle greenhouse gas emissions by almost 61%, using low-soot renewable fuels, which is better than what EVs can achieve.

In addition, according to a study conducted by industry analysts Gladstein, Neandross, and Associates, the implementation of ClearFlame engines would result in lower lifetime ownership costs for fleet operators.

To further commercialize its technology and to market its solutions that reduce carbon and soot, ClearFlame announced today it has raised $30 million in Series B funding. The round was led by Mercuria Energy Group, one of the world’s largest privately held energy and commodities companies, with Mercuria and Breakthrough Energy Ventures both making second investments.

New investors, including mining corporation Rio Tinto, and WIND Ventures, the strategic venture arm of Copec, one of Latin America’s leading mobility and energy companies, see ClearFlame as part of a holistic suite of strategies to advance environmental, social, and governance (ESG) goals.

ClearFlame co-founders CEO BJ Johnson and CTO Julie Blumreiter have dedicated their doctoral research at Stanford University to finding solutions to mitigate climate change and achieve carbon reduction goals by freeing heavy-duty diesel engines from their reliance on fossil fuels. Diesel fuel consumption accounts for approximately 26% of overall CO2 emissions from the U.S. transportation sector.

ClearFlame Founders: Dr. BJ Johnson (CEO) Ph. D Mechanical Engineering and Dr. Julie Blumreiter (CTO) Ph. D Mechanical Engineering

In a statement, Johnson said: “ClearFlame continues gaining momentum with technology that heavy-duty equipment users can deploy to more quickly and affordably meet critical ESG goals. Federal Department of Energy funding moved us from concept to patent. Series A funding propelled us from patent to pilot. This latest investment round can accelerate us from pilot to proven product in multiple markets, starting with long-haul trucks.”

The company’s patented technology runs on a range of renewable liquid fuels. It can efficiently adapt to markets like long-haul trucking, offering the same power, durability, and performance as today’s diesel engines while readily integrating into existing manufacturing, fueling, maintenance, and repair ecosystems. In pursuit of penetrating the more than $200 billion global trucking market, the company is piloting five trucks in collaboration with some of the largest fleet operators in North America. It is also exploring partnerships and applications for the mining, agriculture, and power generation sectors.

“Mercuria was an early adopter of various environmental products in its portfolio and has committed more than fifty percent of all new investments to the energy transition,” said Boris Bystrov of Mercuria. “Mercuria’s strategic investment in ClearFlame’s technology reflects the company’s continued commitment to renewable fuels as part of the energy transition and its belief that ClearFlame’s technology can economically decarbonize the heavy-duty industry by utilizing the existing liquid fueling infrastructure.”

“The diesel engine is the backbone of heavy industry and its advantages make it hard for clean alternatives to compete,” said Carmichael Roberts, Breakthrough Energy Ventures. “ClearFlame has pulled together a new generation of entrepreneurs and veteran engineering talent that have unlocked a viable, cutting-edge solution.”

Brian Walsh of WIND Ventures noted, “We are excited to partner with ClearFlame as they expand into mining, which is a key market for Copec in Latin America. The mining sector is a heavy user of diesel fuel and ClearFlame’s technology can likely enable a rapid transition to methanol fuel for lower carbon emissions while maintaining diesel-like performance.”

“The effort to achieve a sustainable clean energy and fossil-free future has to be inclusive and comprehensive,” noted Blumreiter. “We welcome all partners who see our innovation as a means to make tomorrow’s ESG goals today’s realities.”