Doubling for Diesel

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.
By Matt Thompson | July 13, 2020


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.”

Johnson presented ClearFlame’s technology at the 2020 National Ethanol Conference in February, and he was encouraged by the interest that ensued. “We received very enthusiastic feedback from those who understood the huge creation of ethanol demand that is enabled by our technology,” he says. “There was also significant interest in testing the technology. ClearFlame is hoping to convert this enthusiasm to more tangible support,” he says, explaining that the company is securing additional test fuel and capital.

Full Circle
Walt Wendland, CEO of Ringneck Energy, an 80 MMgy plant in Onida, South Dakota, says he was impressed with Johnson’s presentation, particularly ClearFlame’s potential to increase domestic ethanol demand. “What I liked about it the most was that farmers that bring their corn in would have a great opportunity to buy the ethanol back to fuel their tractors,” Wendland says. “Basically, it’s closing the loop. It’s something that I think would be pretty neat where we’re located.”

Johnson says part of the appeal of ClearFlame’s technology is to protect against poor market conditions and decreased demand for ethanol. “I look at ClearFlame as a hedge,” he says. “If we can be using ethanol both as a gasoline substitute and a diesel substitute, we can be much better insulated from any shock that’s going to affect one market or another. Global recessions are never going to be good, but the more you can hedge and insulate, the better it’s going to be.”

The concept benefits not just ethanol producers, but corn growers as well, Wendland says. “It’s a cliché, but it’s a huge win-win for farmers to lower their costs, and farmers want to support [ag-based fuels],” he says.

Kelly Nieuwenhuis, director of the Iowa Corn Promotion Board and a member of Siouxland Energy Cooperative’s board of directors, is also optimistic about potential new markets ClearFlame may open for ethanol. “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 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.

Nieuwenhuis says he’s fully on board with the potential ClearFlame offers, and has spoken about the engines with other farmers who have been supportive. “Diesel fuel is not going away in a short time, but I think the combination of ClearFlame engines and renewable diesel, and biodiesel, will be a very positive thing for agriculture,” Nieuwenhuis 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.

ClearFlame’s Difference
ClearFlame, Johnson says, is different than some of the other technologies that allow ethanol use in diesel engines. Those technologies, he says, use some other ignition source besides ethanol, such as fumigation, which he compares to running a spark-ignition ethanol engine with a diesel spark plug. “Those solutions work in some applications,” Johnson says. “The reason why they really haven’t found a lot of widespread success is, they’re using two fuels at once, and that’s always an additional level of complication that people don’t want to deal with,” he says, adding that those engines also require the use of the urea-based after-treatment systems.

ClearFlame’s technology simplifies after-treatment but keeps all the other benefits of the diesel engine design, Johnson says. “At ClearFlame, we’re talking about everything you associate with the way a diesel engine works,” he says. “The fuel goes in, it ignites relatively quickly, the combustion proceeds, and you continue to inject the fuel. That allows you to keep all those torque and efficiency benefits you associate with diesel, while also having easy control over ignition.”

Those urea-based after-treatment systems, which are designed to reduce emissions and particulate matter, aren’t needed, as the ClearFlame system takes advantage of ethanol’s clean-burning properties. Johnson says ethanol also offers about a 40 percent reduction in CO2 compared to diesel. “Globally, heavy-duty diesel engines produce about five gigatons of CO2 a year, so a 40 percent savings on that is two gigatons that you’re reducing,” Johnson says. “Of course, you have to have the ethanol capacity to meet that, but that’s something that [shows] we can get the biofuels production up.”

The company announced in April it has secured financing, which will allow it “to accelerate demonstrations of its breakthrough technology,” according to a press release from Clean Energy Ventures. The $3 million initial financing will also be used to pursue further partnerships and commercialization.

Johnson says the ClearFlame technology was developed with co-founder Dr. Julie Blumreiter as part of his graduate research. ClearFlame then worked with Argonne National Lab and proved the technology on a Caterpillar research engine. “Using this $3 million, we can take our results out of Argonne and into our own independent R&D facility, so we can begin the effort of more rapid prototyping.” That prototyping will start with a Cummins X15 engine, he says, but the company has hopes of quickly testing on more engines and different applications and “prove that this technology really does work anywhere a diesel engine can be used across makers and applications,” 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.”

Author: Matt Thompson
Associate Editor, Ethanol Produce Magazine