BJ Johnson and Julie Blumreiter have nothing against electric trucks.
But the duo think the rush to electrify heavy-duty transportation misses an important reality and leaves a yawning gap, which they hope to fill with the engine technology they developed as doctoral students at Stanford University.
Blumreiter and Johnson co-founded ClearFlame Engine Technologies to market engine technology that allows trucks, generators and other motors to run on a variety of low-emissions fuels such as ethanol, methanol or liquid ammonia. While these fuels are not zero emissions, various studies have shown pure ethanol’s life cycle greenhouse gas emissions are roughly 40 percent to 50 percent less than petroleum-based fuel.
Johnson and Blumreiter argue that it will take years to electrify trucking in the U.S., not to mention other countries, hence an affordable, low-emissions diesel-type engine that can run on various fuels can be a boon to reducing transportation sector emissions. The U.S. Department of Energy, industry sources and major investors have taken interest.
In 2017, Johnson and Blumreiter were chosen among the first cohort in Argonne National Laboratory’s Chain Reaction Innovations fellowship program, providing mentorship and access to Argonne’s emissions testing and other equipment. Blumreiter and Johnson moved to the Chicago area for the fellowship, where the company has been based since. ClearFlame has raised close to $50 million in series A and B funding, with about 50 employees and pilot projects underway with major corporations.
John Wall, former chief technology officer for global engine maker Cummins, has been an adviser since the Stanford days. He sees ethanol-fueled trucks with ClearFlame technology providing an important "bridge" to zero-emissions transportation.
Testing has shown that ClearFlame’s engine technology achieves equal or greater torque compared to traditional diesel engines.
"Too many people want to say everything will be battery electric, let’s forget about anything else," said Wall, who also previously worked in diesel research for Chevron. "I’m quite optimistic about battery electric in a number of applications, but some will be hard. Long haul trucking is one of them, and power generation. You don’t want the perfect to be the enemy of the good. If you can get 40 percent emissions reductions now, let’s do that and work on the rest."
Johnson and Blumreiter emphasize that their technology is also well-suited to developing countries, where electrification of transportation is not on the horizon, but feedstock for ethanol — such as corn or sugar cane — is available. And depending on the market, ethanol may be significantly more affordable than diesel.
"This is not just a California solution, this is a global solution to a global problem," Blumreiter said. "Fundamentally, our technology is that we can make the diesel engine design and everything that is good about it operate on any fuel. You can choose fuel based on cost and regional availability."
Several pilot projects are underway with trucks on the roads using engines retrofitted with ClearFlame technology. Blumreiter said she could not name the companies doing the pilots, but they involve at least one major truck stop company and fleet managers who sit on the startup’s fleet advisory council.
ClearFlame markets the technology to allow ethanol or other fuels to be burned in the same type of engine that burns diesel, but at a hotter temperature, which is necessary for ethanol and other fuels to combust.
"If you get it hot enough, anything burns," Johnson said. "We changed the plumbing on the engine so these fuels operate fine. At its heart, it is very simple. The devil is in the details."
ClearFlame relies on U.S.-based manufacturers to build its technology, which can be retrofitted into diesel engines. Ultimately, they hope original equipment manufacturers such as Cummins will decide to build engines with the technology.
Wall said he sees that as a very real possibility, as it is "easy" for a manufacturer to incorporate ClearFlame’s technology into standard diesel engines.
"If a customer calls up and says, ‘I’d like to buy a thousand engines like this every six months for 10 years,’ then you get very interested," he said. "Now BJ and Julie are working with some of the big fleets to have them understand the technology. The feedback I’ve heard so far is quite positive."
One of the beauties of diesel engines is they get used everywhere.
Testing has shown that ClearFlame’s engine technology achieves equal or greater torque compared to traditional diesel engines, and it eliminates the need for filtering out particulate matter and other after-treatment for pollution.
It’s easier to add pure ethanol to existing fueling stations, ClearFlame supporters say, compared to the infrastructure upgrades necessary for electric charging, or alternative fuels such as compressed natural gas or hydrogen. Wall added that trucking companies often run trucks on a major transportation corridor — such as Interstate 65 — for about four years, then the trucks are sold to work in regional markets or local deliveries. So adding electric charging or hydrogen infrastructure to major corridors would not support the existing truck market structure, but fueling stations throughout the country could provide pure ethanol, and ClearFlame engines could also burn E85 fuel — with 85 percent ethanol — that is already widely available.
Johnson said ClearFlame technology could also be used in marine engines, locomotives and other heavy equipment. Mining giant RioTinto is an investor, as the engine technology could help mining companies power their huge machines while reducing emissions. Wind Ventures, an affiliate of major Latin American energy company Copec, is also an investor. Johnson noted that excess wind energy could be used onsite to produce liquid ammonia fuel for ClearFlame engines.
"Trucks are our beachhead," Johnson said. "One of the beauties of diesel engines is they get used everywhere. A lot of pieces of equipment have a diesel engine-shaped hole in the middle."
The company CK Power is piloting ClearFlame’s technology in its mobile gensets, generators targeted for use in utility infrastructure and electric vehicle charging stations. Solar is increasingly used by utilities and for EV charging. But Clayton Costello, CK Power vice president of corporate strategy, said there is "no technology yet on the marketplace" that can replace a mobile fuel-burning generator in many situations.
"As there’s more federal spending [on reducing emissions] and customers have more demand for lower-emissions technology, we see a need in many industries for these types of platforms," Costello said.
A less-traveled road
Blumreiter and Johnson say they feel they are going against the grain in the clean energy startup world, where much attention is focused on zero-emissions and electrification as opposed to low-emissions technologies; and where software and advanced materials are more common focuses than relatively straightforward hardware.
They are also somewhat non-traditional cleantech startup founders. Blumreiter is one of relatively few women in the space; and Johnson is African American and a former national team member in swimming, having started the sport late and peaked in the pool at the same time he was developing the engine technology.
"Competing at a very high level [in swimming] puts the challenges now in perspective," said Johnson, who was ranked second in the U.S. and ninth in the world in 2013. "It’s not the first time I’ve tried to do something hard."
He became deeply interested in climate change around when the film "An Inconvenient Truth" was released, "and it became clear climate change would be the issue of our generation."
Ethanol has been widely criticized as a false hope for climate mitigation, because growing corn involves significant greenhouse gas emissions.
Blumreiter grew up in Wisconsin and always had a keen interest in volunteering. As an undergraduate at Stanford, she took a class in thermodynamics because it was at a convenient time, but realized "this is it! Intellectually I was captured — hook, line and sinker."
She figured her professional and humanitarian interests would progress on parallel paths, but with ClearFlame she feels she is pursuing her passion for technology innovation while also making the world a better place, she said.
"It’s no surprise that people who are doing something that’s completely different than the prevailing approach to decarbonization are two people who don’t look like your average founders," Blumreiter said. "That leads to us taking a more global view and never losing sight of affordability and equity as ingredients in what solutions get to market."
Semi-trucks frequently run on ethanol blends or "renewable diesel" or biodiesel, widely available at service stations. But conventional diesel engines can’t run on pure ethanol or methanol.
Renewable diesel and biodiesel have higher particulate matter emissions than ethanol, while also coming from feedstocks that are not always easily and widely accessible — such as animal fats and used cooking oil.
"Ethanol is two carbons and an oxygen and some hydrogen; diesel are larger-chain hydrocarbons, so is renewable diesel — it’s the longer chains that tend to form soot," Blumreiter said.
Wall said that as the aviation industry tries to reduce emissions, renewable diesel is likely to be increasingly used, diverting availability from the lower-value trucking industry. Meanwhile, as electric cars become more prevalent, demand for ethanol-blend gasoline may go down, lowering ethanol’s market price and making it an even more attractive option for truck fuel, he theorized.
Ethanol has been widely criticized as a false hope for climate mitigation, because growing corn involves significant greenhouse gas emissions and also uses land that might otherwise be growing food. There has been much debate about ethanol’s life cycle carbon emissions compared to fossil fuels, but proponents argue that when best practices are used, its life cycle emissions are significantly lower than traditional diesel or gasoline.
"We didn’t set out to make an engine that ran on ethanol," Blumreiter said. "Ethanol is something [the U.S.] invested in decades ago for energy security reasons. It wasn’t necessarily cheap or clean then, but it is now."
Clean energy incentives such as California’s Low Carbon Fuels Standard and Inflation Reduction Act funds for alternative fuels and fueling infrastructure could help the deployment of ClearFlame’s technology. Johnson said that funds from the Volkswagen settlement and the federal Diesel Emissions Reduction Act could also be used for retrofitted ethanol-burning engines.
But Blumreiter said she feels the company’s success isn’t dependent on incentives; she thinks affordability and convenience will drive deployment, after more testing and pilot programs are completed.
Johnson likes to think of ClearFlame as the "Tesla of heavy duty."
"Tesla was close to a trillion dollars [in valuation] before OEMs [original equipment manufacturers] took electric vehicles seriously," Johnson said. "We’re on fundamentally the same path. You have to go to the market, and prove people want this."