Dickinson plant produces 184 million gallons of 100% renewable diesel
Marathon's production of renewable diesel offers a more efficient and environmentally friendly alternative fuel option
DICKINSON — Marathon Petroleum's latest breakthrough in their fuel production may just be the game-changer the North Dakota industry has been looking for.
The company's renewables business manager claims that Marathon's renewable diesel provides a more efficient and environmentally friendly alternative to traditional fuels, marking a significant step toward a greener future. With concerns about climate change and environmental impact on the rise, this development could prove to be a major turning point in the world of fuel production.
Marathon Petroleum communications manager Jamal Kheiry has disclosed that the renewables plant in Dickinson has employed around 110 workers. The plant started operating toward the end of 2020 and attained full design operating capacity in the second quarter of 2021. Presently, the plant is producing approximately 184 million gallons of renewable diesel annually.
Renewable diesel, a fuel alternative that is made up of various ingredients such as soybean, canola or corn oils, used cooking oil and animal fats, will be largely sourced from North Dakota, according to Justin Womeldorff, Marathon's renewables business manager. The proportion of each ingredient used in the production of renewable diesel varies depending on availability.
“We do have a joint venture with ADM that was announced in June of 2022, to construct and operate a soybean crush facility in eastern North Dakota, in Spiritwood, the Green Bison soybean processing facility. By the seasonal harvest of 2023, that will start supplying approximately 600 million pounds per year of locally sourced soybean oil that will be used as part of our process,” Womeldorf said.
Renewable diesel offers a 100% renewable fuel alternative, setting it apart from ethanol fuel or biodiesel. A recent study published in 2022 by the National Academy of Sciences suggests that the carbon emissions of corn-based ethanol blended fuels are likely much higher than those of traditional gasoline.
The study showed that ethanol has a 24% higher carbon intensity than gasoline, due to the land-use changes required to cultivate more corn, as well as emissions from processing and combustion. Additionally, ethanol has been known to cause fuel line corrosion, particularly in older vehicles.
Womeldorff explained this is not the case with renewable diesel, which he argued is overall more efficient to produce than ethanol. He said it can be used in any diesel engine no matter how old.
“We have to keep track of all the emissions associated with planting a crop in the ground, harvesting that crop, transporting the oil to our facility, processing, all of the emissions associated with the production at our facility, transportation to the target market and ultimate combustion of the fuel. So when you compare that carbon intensity life cycle of renewable diesel to the life cycle carbon intensity of a petroleum diesel fuel, you can have feedstock dependent anywhere from a 40 to 80% reduction in the carbon intensity of that fuel,” he said. “The regulating bodies have very strict requirements for tracking this carbon intensity. It's verified and audited on a regular basis.”
He also said renewable is less harmful to air quality than petroleum diesel.
“When it's being combusted in the engine, gallon-per-gallon comparison to petroleum diesel, renewable diesel is cleaner burning, it produces lower particulate matter content, lower oxides of nitrogen and lower aromatic hydrocarbon emissions than you would expect from a petroleum fuel,” he said.
Womeldorff explained how the production process of renewable diesel involves a unique method of utilizing various feedstocks, including soybean oil and cooking grease, which are transformed through a hydrotreater and hydrodeoxygenation process — resulting in a final product that closely mirrors that of petroleum diesel.
“There are a number of different feedstocks (soybean oil, cooking grease, etc.) that can be used in this process. The feedstocks are fed to what's called a hydrotreater, or high-pressure unit that combines the feedstock with hydrogen and takes it through a hydrodeoxygenation process. As part of that process, we’re removing oxygen from the triglyceride molecule and producing water from that, and then on the back end, we get a diesel range molecule,” he said.
“We further have to take that molecule through a dewaxer isomerization process, which uses a little bit more hydrogen and lowers the cloud point of the resulting diesel. So it’s a parameter that's important to ensure the diesel doesn't gel up at certain temperatures, so we have to lower that cloud point down so that it closely mirrors what we would expect from a petroleum diesel product.”
Womeldorff said the Dickinson renewables plant takes pride in being completely self-sufficient in terms of hydrogen production. The plant has a hydrogen production unit on-site, which generates hydrogen from natural gas via a steam methane reforming process.
“The hydrogen that we use as part of the process is produced in an on-site hydrogen plant that uses natural gas as a feedstock, but also uses waste gases from the renewable diesel process that gets recycled back into that hydrogen plant,” he said.
Womeldorff noted that by the end of Marathon’s refining process, renewable and petroleum diesel are chemically very similar.
“I do want to be clear that the renewable diesel itself is not soybean oil anymore. It's been converted, chemically altered. And it is truly diesel fuel. You can't really even tell the difference between petroleum fuel and renewable diesel from its chemical properties,” he said.
In comparison to biodiesel, renewable diesel is a distinct fuel alternative. Biodiesel can become too cold and gel up, particularly in colder climates and especially with higher blends or those produced from cooking grease. This can create difficulties for fuel pumps and systems. Engines from most manufacturers are designed to function with a maximum of 20% biodiesel blend, and older diesel engines have even lower tolerance levels.
Marathon produces renewable diesel to comply with the Renewable Fuel Standard set by the EPA. The mandate requires energy companies to produce a certain amount of renewable fuel to offset their fossil fuel production. To meet this requirement, smaller energy businesses in the Bakken region, unable to build such large renewable facilities, purchase RINs (renewable identification numbers) from larger corporations like Marathon. By producing renewable diesel, Marathon not only fulfills its obligation under the mandate but also provides a more sustainable and environmentally-friendly fuel alternative.
“There are programs in California, Oregon, Washington, British Columbia, and then soon all of Canada with additional programs coming online in the near future that incentivize the production of renewable diesel. When you look at California in particular, there is an obligation that we have as a petroleum fuel producer and the state requires the purchase or generation of low carbon fuel standard credits,” Womeldorff said. “Right now, the availability is largely concentrated on the West Coast due to those programs and over in Europe, but it is available in small quantities or niche areas throughout the country.”
Marathon's expansion into renewable diesel production is not limited to its Dickinson plant. The company is currently constructing another facility in Martinez, California, which is already producing fuel even during construction. According to Kheiry, the Martinez plant is expected to reach a production rate of 730 million gallons per year by the end of 2023. This expansion will allow Marathon to meet the increasing demand for renewable fuel and reduce the environmental impact of fossil fuels across the nation.