The Chevron Renewable Energy Group plant in Seneca, which has a biodiesel production capacity exceeding 60 million gallons annually, is situated on approximately 50 acres bordering the Illinois River. Plant Manager Jerry Claggett highlighted the advantage of having three transportation options, including access to the Mississippi River via the waterway.
"We are very fortunate to be in the heartland of Illinois, very close to interstate corridors," Claggett said. "We are serviced by CSX as our main rail provider, and we do have the ability to bring feedstocks in and ship fuels out via the Illinois River, connecting from the Great Lakes to the Gulf. We (also) use trucking. That’s a great advantage that this facility has where most don’t, is the ability to move commodities in different ways."
More than 60 years before its biodiesel operations, the industrial park in Grundy County played a significant role in World War II, serving as a shipyard for building Landing Ship, Tank (LST) vessels from 1942 to 1945, which were crucial for Allied invasions.
"Most people don’t know that the facility supported World War II activities," Claggett noted.
In 2022, Chevron Corporation acquired Renewable Energy Group, and now operates nine biorefineries across Illinois, Iowa, Minnesota, Louisiana, Washington, and Germany.
Claggett, who has managed the Seneca plant for six years, has been with the biodiesel facility since 2010. The employees primarily reside in Grundy and La Salle counties.
"We have two operating biodiesel plants in Illinois; between Seneca and Danville, we have 87 employees," he stated.
In addition to biodiesel, the plant produces a co-product, technical-grade glycerin, which Chevron markets.
"The last few years, market conditions have been pretty challenging," Claggett said regarding the biodiesel industry. "We have seen a change this year (with more supportive federal policy) and we are seeing stronger market demand."
Supportive policies, such as Illinois' sales tax exemption for retailers selling biodiesel fuels, are designed to boost soybean sales. The state has progressively increased the biodiesel proportion required to qualify for this exemption.
"Many states have their own biofuels legislation in place," he said. "We are very fortunate that we’re in a state that does support biodiesel with a minimum blend requirement increase that came this past April up to B20 (a fuel blend made with 20% biodiesel). But not all states carry that same local support or mandate."
The Seneca plant utilizes a diverse range of feedstocks, including vegetable oils, used cooking oil, waste greases, and animal fats.
"We use about everything that’s available in the marketplace at this facility.
"We (use) predominately vegetable oils; being right here in the Midwest, there are a lot of vegetable oils available," he explained. "Short transportation, good winter properties, supporting local farmers, things like that are the reasons why we like to consume them. They come with improved cold weather properties that we also like because in the wintertime in the Midwest, it does get pretty tough. There’s a lot of ethanol in the Midwest, and their co-product, distillers corn oil, is also a feedstock of ours."
The Seneca facility contributes to the broader agriculture and renewable fuels value chain by creating demand for feedstocks and converting them into fuel usable in transportation and other diesel-powered applications, including agriculture. Claggett mentioned that John Deere recently approved B30 biodiesel blends for all Tier 4 John Deere power system engines, an increase from the previous B20 approval.
"I feel there’s a lot of support for renewable fuels in a lot of different areas,"
When Renewable Energy Group was acquired by Chevron in 2022, it enhanced Chevron’s renewable fuel capabilities.
"It brought biodiesel production, like the Seneca facility, into their broader business, but Chevron has invested in a number of other lower-carbon solutions: renewable diesel, renewable natural gas, sustainable aviation fuel, renewable naphtha, hydrogen and carbon capture. There’s a wide array of renewables support,"
"Chevron continually evaluates opportunities to improve operations, reliability, carbon intensity," he said. "Currently right now, they are evaluating opportunities at both the Illinois facilities for on-site solar to reduce their carbon intensity."
As the company explores its on-site solar energy needs, site evaluations are underway.
"The solar opportunity is the big one that we foresee coming."
The history of diesel energy traces back to engineer Rudolf Diesel, who patented the compression-ignition engine in 1892, designed to run on vegetable oils. He demonstrated this with peanut oil at the 1900 World's Fair in Paris.
Today, Chevron describes its biodiesel as a lower-carbon fuel with significantly reduced emissions, offering benefits such as improved vehicle and cold weather performance, and reduced engine wear.
Financial impact
"Chevron spent more than $1 billion in 2025 on total goods and services in the state of Illinois," Claggett said, referring to the company’s economic impact. "That’s anything from buying commodities to skilled labor – so quite a bit of financial impact to our areas and to our customer base."
The plant is integrated into the local communities.
"Chevron really values the relationship with both the Seneca and Morris areas," Claggett said. "We have engaged with our local police, fire, and economic development partners. We’re trying to strengthen relationships, support emergency preparedness, and just stay connected with any sort of community priorities. I do feel like we have a really strong relationship with all those different entities."
Nancy Norton, president and CEO of the Grundy County Economic Development Council, which is celebrating Manufacturing Month, stated that the biodiesel plant has been a valuable partner to Grundy County.
"Interestingly, they sit right on the border of Grundy and La Salle," Norton said. "It’s really impressive the amount of people that they employ, the hundreds of thousands of gallons of biodiesel that they produce that certainly helps our environment every day, as well as providing really good jobs and buying feedstocks that go into their plant from local sources. They operate down by the river, and a lot of people don’t know that they are there and appreciate all the great things that they do there."
