ClearFlame Engine Technologies

ClearFlame Engine Technologies is a Geneva, Illinois-based clean-energy startup founded in 2016 that has developed proprietary engine modification technology enabling diesel engines in heavy-duty trucks, agricultural equipment, and power generation to run on low-carbon, renewable fuels such as ethanol — without the need for complex aftertreatment systems. The company's approach breaks the dependency between the diesel engine architecture and diesel fuel, delivering near-equivalent performance and efficiency while significantly reducing greenhouse gas emissions and particulate matter. ClearFlame raised a $17 million Series A in October 2021 led by Breakthrough Energy Ventures with participation from Mercuria, John Deere, and Clean Energy Ventures, following an earlier $3 million seed round and $4 million in non-dilutive grants. The company was co-founded by CEO BJ Johnson and CTO Julie Blumreiter, both of whom developed the core technology during their doctoral research at Stanford University.