Company Advances Ethanol Diesel Engine

Source: By Todd Neeley, DTN Staff Reporter • Posted: Thursday, October 15, 2020

ClearFlame Truck Engine That Can Run on Straight Ethanol Passes Torque, Power Test

ClearFlame Engine Technologies has achieved a milestone in developing a heavy-duty truck engine that can run on straight ethanol. (Photo courtesy of ClearFlame Engines)
ClearFlame Engine Technologies has achieved a milestone in developing a heavy-duty truck engine that can run on straight ethanol. (Photo courtesy of ClearFlame Engines)

OMAHA (DTN) — A start-up company developing a heavy-duty truck engine able to run on straight ethanol has reached a milestone in a series of tests performed to validate its technology.

ClearFlame Engine Technologies reported in a news release on Wednesday it matched the torque and power of a commercial diesel engine using ethanol in place of diesel.

The company said the technology delivered 500 horsepower and more than 2,500 foot-pounds of torque, “while eliminating the need for additional aftertreatment such as selective catalytic reduction or diesel particulate filter systems.”

ClearFlame said it achieved the latest results on a Cummins X15, a 500-horsepower, 15-liter heavy-duty engine using the company’s high-temperature stochiometric combustion process.

The process leverages higher temperatures to achieve diesel-style combustion of any decarbonized fuel.

ClearFlame Engines CEO B.J. Johnson told ethanol industry representatives at the National Ethanol Conference in Houston in February 2020 the technology has the potential to create a large market for ethanol. He said even an optimistic 20% market penetration into the $231 billion heavy-duty diesel market would create 15 billion gallons of demand for ethanol per year.

“The results from ClearFlame’s first commercial platform tests are extremely promising and demonstrate a real world, sustainable solution for diesel engine manufacturers as decarbonization requirements continue to evolve in the off-highway, heavy-duty and industrial sectors,” Johnson said in a statement.

The reason ethanol’s application in diesel engines hasn’t happened is because the performance and simplicity of the diesel engine is tied to its dirty emissions, Johnson said.

Cleaner alternatives like spark ignition lack the performance required in many heavy-duty applications. ClearFlame’s engine, Johnson said, is the only option to provide both high performance and low emissions.

The engine, still in the demonstration phase of development, can run on 98% ethanol straight off the rack or even on E85 so long as the fuel is close to 85% ethanol.

“The results we’ve seen on the Cummins engine mark a critical milestone in the commercialization of ClearFlame’s technology,” said Julie Blumreiter, chief technology officer and co-founder of ClearFlame.

“Achieving these key targets without the use of complex aftertreatment systems helps diesel engine manufacturers to preserve their core engine technology requirements, driving a cost-effective, rapid-to-market solution that addresses evolving emissions regulations.”

A selling point for the ClearFlame technology is it has the ability to replace petroleum fuels with ethanol in order to reduce greenhouse gas emissions as well as particulate matter and smog, at the same time reducing overall engine cost.

ClearFlame is working with Cummins Inc. and Argonne National Laboratory to develop the technology. Johnson said diesel fleets would have the potential to achieve a 40% reduction in carbon emissions and a $45,000 cost savings.

All the while, the ClearFlame engine has 30% more torque than engines running on diesel.

The diesel sector spends about $3.3 billion in aftertreatment each year. Using ethanol in a diesel engine could save the sector $2.5 billion in aftertreatment costs, Johnson said.

Although gasoline demand is expected to decrease in the next 20 years, he said, demand for diesel is expected to remain high. In addition, he said the price of ethanol is expected to remain low relative to diesel prices for decades to come.

The ClearFlame engine is the only diesel engine that would meet California regulations on reductions in nitrous oxide emissions, Johnson said, and ethanol would help the state accomplish that goal.

The company has about two to three years of demonstrations to complete, starting in 2021. Johnson said ClearFlame plans to scale up the technology in 2026 or 2027 and hopes to sign a license agreement with an engine manufacturer.

Johnson and Blumreiter are graduates of Stanford University and started ClearFlame based on work from their dissertations. The Chicago-based company received $25,000 in seed money from Ag Startup Engine at Iowa State University Research Park in 2019.

Johnson and Blumreiter have been participating in Chain Reactions Innovations, an entrepreneur program with the U.S. Department of Energy at Argonne National Laboratory.

The company has received several small-business research grants totaling nearly $2 million.

In April 2020, ClearFlame closed on a $3 million initial round of financing from Clean Energy Ventures, along with other investors to help accelerate the development of a diesel engine that can run on ethanol.

ClearFlame recently completed a proof-of-concept demonstration on a Caterpillar engine at Argonne National Laboratory and is preparing for a commercial prototype demonstration on a Cummins 15-liter engine.

Todd Neeley can be reached at