ClearFlame Engine Technologies secures $17M in Series A financing
29 October 2021
ClearFlame Engine Technologies, a startup developing net-zero engine technology (earlier post), has secured $17 million in Series A financing, which will enable commercialization of the company’s innovative engine technology for the long-haul trucking, agriculture and power generation sectors.
The financing was led by Breakthrough Energy Ventures with participation from Mercuria, John Deere and Clean Energy Ventures.
The company’s engine technology enables low-carbon, renewable fuels such as ethanol to be integrated easily into existing diesel engine platforms, offering a lower-emission, lower-cost solution than diesel fuel. ClearFlame’s solution, grounded in technology developed during doctoral studies at Stanford University and validated using more than $3 million in grant funding, elevates combustion temperatures in order to enable use of non-traditional fuels without sacrificing performance.
Without soot from diesel fuels, compression ignition engines are no longer limited to lean operation and can instead use the chemically correct (i.e., stoichiometric) air-fuel ratio, the company explains. ClearFlame uses soot-free “Clear” Exhaust Gas Recirculation (EGR) to maintain this ratio under varying load conditions.
Stoichiometric operation substantially increases power density and leaves an exhaust composition suitable for three-way catalysis (TWC) instead of Selective Catalytic Reduction (SCR) using urea/ammonia (DEF). Simplifying the engine’s aftertreatment system improves its reliability and reduces its cost by about 75%. It also improves its NOx reduction capability to near-zero levels. Using soot-free fuels also eliminates the need for a Diesel Particulate Filter (DPF).
A ClearFlame-enabled engine meets the performance and efficiency requirements for diesel engines while significantly reducing greenhouse gas emissions and particulate matter, helping to improve air quality and mitigate climate change.
Our technology will enable the rapid decarbonization of diesel-dominated sectors, and this funding advances our path to commercialization with demonstration trucks on the road by the end of this year, in parallel with agricultural equipment and generator set deployments in 2022.
—BJ Johnson, ClearFlame CEO and co-founder
Previously, ClearFlame has received $4 million in non-dilutive and grant funding from the Iowa, Minnesota, Kansas and Illinois Corn Growers Associations, the National Science Foundation, the Department of Energy, and others. The company completed its $3 million Series Seed financing in early 2020, led by Clean Energy Ventures.
Non-lean operation and high temperatures both increase NOx. Stoichiometric or rich combustion also increases soot. No such thing as "soot free" fuel. Soot is carbon so if it's a carbon containing combustion fuel you have to address soot. Lean combustion does that. As for compression ignition of ethanol, I would not like to be around that thank you. "Simplifying the engine’s aftertreatment system improves its reliability and reduces its cost by about 75%" is just poppycock.
Posted by: Emphyrio | 29 October 2021 at 10:57 AM
Non-lean operation and high temperatures both increase NOx.
You might want to read “How Does a Three-Way Catalyst Work?”
https://www.nettinc.com/information/emissions-faq/how-does-a-three-way-catalyst-work
Also, Selective Catalytic Reduction (SCR) using urea/ammonia (DEF) are additional expenses to operating a Diesel engine (just ask VW).
Generally, fuels with higher C/H (carbon-to-hydrogen) ratio produce more soot,e.g. Diesel fuel vs Ethanol.
https://www.sciencedirect.com/topics/earth-and-planetary-sciences/soot
ClearFlame’s solution is based on technology developed during doctoral studies at Stanford University which used Thermal Barrier Coatings to increase combustion temperatures (reference:
https://stacks.stanford.edu/file/druid:cp633zj5935/thesis_BernardJohnson-augmented.pdf).
From the earlier post: “ In a high-temperature environment, any fuel will behave like diesel fuel, having short ignition delay and burning as it is injected in a mixing fuel plume.”
The Scania Bioethanol Engine has a different approach using the heavy vehicle grade fuel ED95 ( bioethanol blended with an ignition improver)and SCR aftertreatment.
https://www.scania.com/group/en/home/newsroom/news/2018/first-scania-bioethanol-truck-hits-the-road.html
Posted by: Account Deleted | 29 October 2021 at 01:04 PM
From: “How Does a Three-Way Catalyst Work?”
https://www.nettinc.com/information/emissions-faq/how-does-a-three-way-catalyst-work
“At lean fuel mixtures the exhaust gases contain little carbon monoxide or hydrocarbons but high concentrations of NOx. Rich mixtures produce high concentrations of CO and HC with little NOx. In order to achieve high simultaneous conversions of CO and NOx, their concentrations in the exhaust must be in stoichiometric proportion,.“
Posted by: Account Deleted | 29 October 2021 at 01:17 PM
Take it from a car guy: engines do NOT operate continuously at stoichiometric. They switch from lean to rich and back again, loading the NOx catalyst with oxygen and then consuming it with a slug of rich gas so the next lean phase can load it again.
Posted by: Engineer-Poet | 31 October 2021 at 02:16 PM