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Government officials demand that automakers future-proof their trucks, but it’s anyone’s guess how they’ll do it. Battery-powered pickups were supposed to be a boon for EV adoption but sales are stumbling and charging still sucks. The difficulties only snowball when towing, so you can forget about an electric heavy-duty model anytime soon. Meanwhile, traditional diesel is embroiled in controversy as the EPA takes on tuners and manufacturers over pollution, while owners are fed up with high-maintenance emissions control systems on their high-dollar pickups.
It’s kind of a mess, plainly put. Even if you look past the troubles of pulling heavy trailers with electric dually trucks, they’re bound to be cost-prohibitive for the average individual and small fleet operator. And even though some are confident that hydrogen will work, either in combustion engines or fuel cells, the refueling infrastructure might as well be nonexistent. But there is another way—a proven technology that once looked like the future but has since faded from the picture. I’m talking about biodiesel.
Now, when most people hear “biodiesel,” they assume one of two reasons it hasn’t caught on: A.) It’s for hippies and B.) it’s just as impractical as the alternatives. But while thinking on a potential fix for the spot we’re in, where petroleum diesel is dirty and emissions equipment is unreliable, I couldn’t help but wonder why a largely plug-and-play solution offering the same fundamental benefits wasn’t getting any attention. That’s why I’ve spent months investigating what happened to biodiesel: the original promise, the science, the stumbles, and the chance of it ever making a comeback. Here’s what I found.
What Is Biodiesel, Anyway?
We’re going to get nerdy for a second, so stick with me.
The United States Department of Energy defines it as “a renewable, biodegradable fuel manufactured domestically from vegetable oils, animal fats, or recycled restaurant grease.” It’s often mixed with petroleum diesel, seamlessly in blends up to B5 (meaning 5% biodiesel and 95% fossil fuel by volume) and more heavily in blends B6-B20, which modern diesel trucks can run without modification. B100, as you probably guessed, is pure biodiesel. The American Society for Testing and Materials sets highly detailed standards for fuels to qualify as B6-B20 (ASTM D7467) and B100 (ASTM D6751).
Biodiesel is produced through the process of transesterification and before you ask, no, I didn’t know that word six months ago. Anywho, this converts anything from veg oil to beef tallow and oilseed feedstocks such as camelina into long-chain mono-alkyl esters. They’re then reacted with some type of alcohol, typically methanol, in the presence of a catalyst like sodium methoxide. One hundred pounds of oil, fats, or grease combined with 10 pounds of alcohol yields 100 pounds of biodiesel and 10 pounds of glycerin, a byproduct that’s either sold as-is or incorporated into skincare and cosmetic products as well as foods and medicines.
It’s commercially available, most broadly in the Midwest United States thanks to those regions’ production of related agricultural goods.
In addition to its renewable fuel status, biodiesel is also valuable for its low carbon intensity. This is the real kicker as it can drastically reduce the production of certain greenhouse gases—y’know, the pollutants that modern diesel emissions systems are designed to trap in the first place. Burning soy-sourced B100 results in 67-77% lower greenhouse gas emissions than burning petroleum diesel. That’s huge.
Combusting biodiesel produces far less soot than petroleum diesel, too, which has practical benefits that we’ll get into here shortly.
How It Came to Be
The first batches of American biodiesel were brewed more than 30 years ago by Missouri farmers with a problem to solve. In 1991, these aggies were growing soybeans and lots of ’em. While about half of their total soybean output was exported, the other half was crushed to separate the rich protein meal from the oil. Farmers had no problem selling the meal, but they were left with huge amounts of excess oil because there was no widespread use for it. That’s when they had their aha! moment.
Don Scott, an engineer and renewable fuels expert who’s spent nearly 20 years advocating for biodiesel, tells me the story:
“Some farmers had been to Europe and saw what they were doing with rapeseed oil [as an alternative fuel], and they wondered if they could do the same thing with soybean oil. They supported some research at the University of Missouri to see if they could run diesel engines on soybean oil or biodiesel. They proved, yes, in fact, that they could do that.
“Well, technically, they could do that.”
Lack of industry was the next obstacle these farmers needed to overcome. To turn the barrels and barrels of excess soybean oil into something marketable, they needed movers, shakers, and producers who would not only do the grunt work but do it in spite of Big Oil. Fossil fuel companies had an even tighter grip on the transportation space in the ’90s, and the Missouri boys knew they’d need more hands on deck to take biodiesel big time. They teamed up with other states in 1992 and formed a trade association that became the National Biodiesel Board.
Scott was an ag engineering student at Mizzou during that time. He reminisced with me over the phone, “I was like, ‘Well, that’s great. Good luck to the farmers, but I’m going to save the environment.’ I finished my degree and I went to work for the Department of Natural Resources, and we did good work there, improving the environment. But by 2006, I’m like, ‘I think the thing that’s really hurting the environment the most is petroleum.’ And at that time, energy security was a big deal—we just had our second Gulf War—so that’s when I really got interested in biodiesel because it addressed all of those things.”
Scott joined the National Biodiesel Board and eventually became its director of sustainability. Biodiesel rose in popularity during Scott’s tenure there, particularly in the late 2000s and early 2010s, just as diesel truck emissions equipment came into play. It even garnered manufacturer support when Ford advertised B20 biodiesel capability on every Super Duty with a Power Stroke engine from 2011 to 2016, putting a plaque at the bottom of the driver door.
“Oh, we were so proud of that,” Scott exclaimed. “We were so proud of that B20 badge when they started doing that. That was the pinnacle. That was awesome.”
Biodiesel’s expansion didn’t stop there, either. Cummins’ entire lineup is capable of running on B20 blends, and for the manufacturer’s R2.8 crate engine program, it actually invited Scott to promote biodiesel alongside the power plant.
(Side note: Cummins also got Scott to create an Instagram account, which now has more than 12,000 followers who look for his next update on whatever WWII-era Dodge Power Wagon or Kaiser Jeep he’s working on. Scott will tell you that he’s passionate about saving the environment, and because of technologies like biofuels, he’s confident he can help do that while driving old trucks. He’s an easy guy to root for.)
This relationship with one of the world’s largest diesel engine manufacturers paved the way for Scott and his colleagues to pitch Cummins on a big idea for its 100th birthday: Make biodiesel the fuel for your next 100 years. Cummins didn’t say no, but it didn’t say yes, either. Instead, the industry giant took a spray-and-pray approach with fuel-agnostic engines like the X15 that can run on almost anything—including biodiesel, but also natural gas and even hydrogen.
About that same time, Ford dropped the B20 door badge from its diesel Super Duty trucks and the public got quiet about biodiesel. Momentum fell off and interest shifted. Scott, still a believer and proponent of the fuel, left the National Biodiesel Board (now called Clean Fuels Alliance America) in 2020 to oversee sustainability certifications for renewable fuels and circular materials at SCS Global.
For most people, this is when the buzz surrounding biodiesel stopped.
Why It Stalled Out
Before we analyze the data, we have to acknowledge the cultural problem that stunted biodiesel’s growth, at least among pickup drivers. While Ford and Cummins dedicated advertising dollars to promoting cleaner fuel, people who actually owned the products were actively making their trucks dirtier by removing their emissions equipment. Some did this because of the systems’ aforementioned unreliability; others did it to gain performance. No matter the motivation, sustainable fuel just wasn’t a priority for your average dually driver, particularly in the early- to mid-2010s before EPA enforcement shot up. Individuals make up a far smaller portion of fuel consumption than commercial fleets, but you can’t discount their influence on public perception.
If you’re really looking for something to point your finger at, poor availability could well be the culprit that’s limiting biodiesel adoption. Sure, it would be great for Cummins, or Caterpillar, or whichever truck company to build engines that run on B100, but where would drivers get it? It’s only natural to ask those questions at the start of the process but even now, in 2024, the U.S. Department of Energy’s biodiesel fueling station map shows a high concentration in Illinois, Iowa, Minnesota, and… that’s pretty much it. You’re more likely to find one in the Midwestern states than anywhere else, but still, it’s tough to locate a station that carries B100 in Missouri, the state that started it all.
Part of the reason nowhere carries biodiesel is because it can be challenging to store. As the National Renewable Energy Laboratory points out, most biodiesel is kept in heated, aboveground tanks for blending. That’s because B100’s cloud point, the temperature at which crystals begin to form in the fuel, can vary from 27 degrees Fahrenheit all the way up to 60 degrees or higher. Different blends mean different cloud points and, therefore, require different storage setups.
Because current cold flow additives aren’t effective in biodiesel like they are in conventional diesel, it’s crucial that the storing conditions are adequate. The crystals will eventually dissolve back into the fuel as it warms and stirs, but that doesn’t matter if you need fuel immediately and it’s gelled up. Underground storage is arguably the best solution since temperatures there typically bottom out around 45 degrees Fahrenheit—warm enough for most biodiesel feedstocks, but again, not all.
Domestic biodiesel production and consumption have nearly aligned in the past half-decade, but only after supply was far outdone by demand. It reached a critical point in 2016 when consumption peaked but there was a 500 million gallon production deficit, according to U.S. Energy Information Administration data. The two figures grew closer to parity from there, with consumption still outpacing production by a hair in 2023. Still, it’s better than it once was.
Pricing varies from place to place as some states incentivize biodiesel as a renewable fuel while others don’t. As of April 2024, the national average price for a gallon of B100 was $4.42—an 86-cent premium over conventional diesel. Meanwhile, B20 actually undercuts conventional diesel by seven cents per gallon on average.
There’s also the hurdle of converting a vehicle to run on pure biodiesel. While most lubricants and filters are compatible with B100, some hoses and gaskets are not—particularly those made of polypropylene, polyvinyl, and Tygon. That can cause obvious issues such as fuel leaks, which might spell disaster if combined with a hot engine.
Truthfully, this is a minor blocker for folks considering the switch to biodiesel, but it still has to be acknowledged.
What Biodiesel Can and Can’t Do to Solve the Emissions Crisis Now
Despite the drawbacks, there are still people who believe biodiesel is a better way forward than electrification. One that I spoke with is Colin Huwyer, CEO of Optimus Technologies. Huwyer’s company has been converting heavy trucks to run on B100 for 14 years now, and they claim 100% carbon reduction compared to traditional diesel. Vehicles with the company’s Vector System retain their factory emissions equipment, but importantly, Optimus claims its tech improves the reliability of said components while also cutting CO2.
“We’re always starting the engine and shutting the engine down on traditional diesel,” Huwyer explains. “These emission systems take a little bit of time to come up to operating temperature, and they’re not really effective until they’ve come up to operating temperature and stabilized. The first aspect of the technology, we start the engine on traditional diesel, bring the engine and the systems up to stable operating temperature. At that point, we’re switching over to biodiesel, and we use biodiesel for the duration of traditional operation.”
It’s a two-tank system, then. Petroleum diesel is used to start the truck, reach operating temperature, and eventually shut it down to purge the lines of biodiesel. And because trucks with this equipment installed spend most of their time burning B100, it takes way longer for their diesel particulate filter to get clogged with soot—Optimus claims a 102% improvement on regen intervals. That means trucks can go twice as long without initiating a superheating event to clear the carbon buildup, extending the equipment’s lifespan. And because biodiesel has a much higher flash point than diesel, Optimus’ equipment communicates with the engine controller to switch over to traditional diesel to carry out the regen.
“It allows us to take advantage of the emission reductions that biodiesel provides while avoiding the detrimental aspects of biodiesel that occur when the regeneration process happens,” Huwyer added.
ADM Trucking ran five tractors with the Optimus Vector System for 1.3 million miles. Over the course of the test, the logistics company measured a 1.3% increase in fuel economy, a 32% reduction in ash accumulated in the DPF, a 22% reduction in time spent actively regenerating the DPF, and an overall reduction of over 50% in the total number of active DPF regenerations. They burned 77,424 gallons of B100 and 993 gallons of conventional diesel, offsetting carbon emissions by 943 metric tons. That’s about as good as you can hope for.
So with all these benefits, you might wonder why trucks need to retain their emissions equipment at all. There’s a simple answer to that: burning biodiesel actually creates more nitrous oxide, or NOx, than traditional diesel. Exactly how much more is debated across academic papers and studies, but because they’re still a factor in biodiesel blends B20 and up, a select catalyst reduction system using diesel exhaust fluid is still required.
Huwyer says that modern diesel emissions equipment is just as capable of filtering out the excess NOx from biodiesel as petroleum diesel, effectively making it “NOx neutral.” That’s the benefit of retaining the factory hardware while reaping the carbon benefits of running biodiesel.
In short, biodiesel can make a mighty difference in reducing emissions. It knocks down carbon dioxide immensely, and while it can’t solve the NOx problem, it doesn’t have to thanks to new technology in diesel engines. Combining a cleaner fuel like biodiesel with the work that’s already been done in the field of emissions control could drastically improve our environmental situation while also being far more affordable than electrification. Plus, it’s here right now. No waiting, no nothing.
Where Does It Go From Here?
That’s the multimillion-dollar question. Biodiesel seems like a logical path forward for the transportation and logistics industry, but it faces a regulatory battle that won’t be easy to fight. As Huwyer tells it, that’s because some states are still pushing for electrification despite its cost and complexity:
“There are some detrimental regulatory policies today, and some of it’s being led by California that even though the objective is carbon reduction, the way the policy is prescribed, it is actually a technology-driven approach [and] electrification is the only strategy. There’s a little bit of conflict between what the objective is and the pathway to getting to that objective.
“Anytime we talk to legislators or policymakers, we always try and share that perspective because the goal is, ‘How do we reduce carbon emissions? How do we set a cap on carbon emissions?’ The way to get there should be absolutely anything and everything that allows us to get there. What we’ve seen from a policy standpoint is prescriptive solutions that say, only electric vehicles will get us there.”
Huwyer makes the point that in Pennsylvania, where Optimus is based, coal and natural gas are the main sources of energy for electricity. Policymakers overlook this while pushing for EVs and either forget or ignore that both of those produce carbon and methane. The very elements these regulations supposedly seek to reduce are still being released at a large scale; they’re just moved upstream in the manufacturing process.
On the other side of the coin, biodiesel doesn’t require much. As Scott told me, “It’s basically turning sunshine into money, right? … If we want to extract some natural resources, let’s extract photons because they’re raining down on us every day anyway. Let’s use that solar energy.”
It ultimately comes down to two things: performance and convenience. The first one is already taken care of—old and modern diesel engines alike are proven to run great on biodiesel—but Big Oil stands in the way of the second one.
“The reason that diesel has emerged over the last 100 years as the staple of the industrialized world for cargo, transportation, shipping, and construction is because of the opportunity that these fuels and these technologies provide to our industry,” Huwyer said. “Being able to leverage the benefits of the engine technology with a cleaner fuel is critical to ensuring their legacy. We’re able to do that, providing the same power, the same performance, the same reliability.
“I think that, again, whether it’s from an enthusiast standpoint or a commercial fleet standpoint, I think that’s the most critical aspect. Because if it’s not as reliable, it doesn’t have the same power, it doesn’t provide the same duty cycle, then you’re fundamentally going to struggle for a long-term adoption because it’s just not a true replacement. That’s where biodiesel has a key advantage, is that it can meet all those criteria.”
To tell it like it is, biodiesel is a viable fuel for the United States. Is it perfect? Nope. But it makes the same power as regular diesel while prolonging the life of emissions equipment and decarbonizing fleets at scale. Whether biodiesel takes off as a go-to option for commercial or personal vehicles isn’t up to farmers or even drivers—instead, its fate lies in the itchy hands of Big Oil, as well as the regulators it influences.
Got a tip or question for the author? Contact them directly: caleb@thedrive.com
