Doubling for Diesel: A Novel Engine Technology

by Matt Thompson (Ethanol Producer Magazine) A novel engine technology could make it possible for ethanol to be used in compression-ignition engines, opening up a potential multi-billion-gallon market. With $3 million in financing secured, Clear Flame Engines is poised for commercialization. -- It sounds almost too good to be true, but a new technology has surfaced that might enable heavy-duty diesel engines to run on ethanol, opening up a whole new market for the biofuel. Gasoline and ethanol use fell off a cliff when COVID-19 struck America, while the diesel fuel used for freight was relatively unaffected. Trucking carried on while Americans stayed apart and stayed home.

Now, a technology from ClearFlame Engines may provide an avenue for ethanol to diversify its market by becoming a substitute for diesel in compression-ignition engines. According to BJ Johnson, ClearFlame’s CEO, the technology works by changing the way heat is managed within an engine by using insulation and managing exhaust flow. “These changes raise combustion temperatures just enough to allow less reactive fuels like ethanol to combust quickly and very efficiently with low emissions, all with no loss of performance,” he says. He adds that the technology can be added to any compression engine that runs on diesel, which is a significant market.

“Globally, hundreds of billions of dollars’ worth of diesel engines are produced each year, and hundreds of millions of these engines are currently in use,” he says. “The United States alone uses 40 billion gallons of diesel fuel each year, and this is expected to grow. Substituting for 20 percent of this total would double demand for U.S. ethanol.”

Engines that operate with ClearFlame’s technology can use any ethanol blend that doesn’t produce a significant amount of soot when burned, Johnson says, which includes E98 blendstock and E85 with an ethanol content of at least 70 percent.

Johnson says the advantages of using ethanol in diesel engines include lower emissions and lower carbon intensity for any operation that currently uses diesel fuel. And because decarbonizing heavy-duty applications is difficult, ClearFlame’s technology has “tremendous value in sectors where there are few other alternatives, like freight transportation, agriculture and construction.”

Moving Forward
While ClearFlame’s potential benefit to ethanol producers sounds promising, commercial use of the technology won’t be immediate. Johnson says ClearFlame has proven the technology’s concept and is working to integrate it into commercial engines. “We are doing this now on a 15-liter Cummins engine with results expected by Q3 2020,” he says. “After that, in late 2020 and into 2021, we would like to begin preparing for several pilot demonstrations using real-world applications like power generation to prove the power, efficiency and emissions in the field.”

“When [Johnson] told me the thought process of ClearFlame Engines was to look at locomotive engines and large tractors—industries that don’t go to retail fuel stations for their fuel, that have their own terminal—I thought, ‘Wow, that’s the way to go,’ because we can ship E98 right from an ethanol plant,” Nieuwenhuis (Kelly Nieuwenhuis, director of the Iowa Corn Promotion Board) says. “Now, what we need to do is sit down and visit with the ag manufacturers—all of them—and get them looking into this new engine design, and working with ClearFlame Engines to try [introduce them into] their large tractors,” he says.

Nieuwenhuis also agrees that the potential to reduce the carbon intensity of farming itself is an exciting prospect. “Because that’s a new thing that’s kind of just getting off the ground—carbon sequestration and carbon credits aimed at the farmer—and we need to be involved in that conversation, too,” he says.

Engine manufacturers also appreciate ClearFlame’s ability to simplify a typical after-treatment system for diesel engines. Those systems, Johnson says, “are expensive and complex, and they struggle to scale more and more to increasingly stringent emissions regulations.” ClearFlame’s technology uses a catalytic converter similar to those used on gasoline cars rather than urea-based after-treatment systems, he says. “One of the things that gets OEMs [original equipment manufacturers] very excited, especially in geographies like the U.S. that are very sensitive to smog, is being able to meet not just current, but next-generation smog standards at decreased cost, and with much simpler after-treatment, but while still remaining in a diesel-style engine configuration,” Johnson says.

Johnson says, in addition to decarbonizing heavy-duty transport, his goal is to remove some of the stigma around combustion. He says combustion as a transportation technology isn’t inherently worse than other technologies, like fuel cells. “When people compare ClearFlame to something like a fuel cell, I think the narrative out there is that, ‘A fuel cell must be better than what ClearFlame is doing, because fuel cells are better than combustion,’ but that’s simply not true,” Johnson says. “I think that’s an important part of being able to expand the impact of decarbonization: We need to make it more about the fuels that we’re using and less about how we’re using them.” READ MORE