In response to sustainability goals, the freight rail industry is working to boost the use of lower-carbon intensity fuels in diesel-powered fleets to support global efforts in mitigating climate change.
Biodiesel and renewable diesel are two types of biofuels, which are produced from organic materials including plants, agricultural waste and wet waste. While these two fuels are produced by different processes, both are often blended with petroleum-based diesel fuel to create lower-carbon intensity fuels that can reduce dependence on fossil fuels.
While these fuels will play a key role in reducing the impact of carbon dioxide emissions, there are challenges to widespread use.
Testing is required to ensure these fuels can be used at a higher percentage without impacting engine performance, which would allow the rail industry to use existing fleets while lowering the impact of CO2 emissions.
Building on their 25-year relationship, the U.S. Department of Energy’s (DOE) Argonne National Laboratory and Progress Rail, a Caterpillar company, are researching a variety of biodiesel and renewable diesel fuels with the goal of lowering the carbon intensity of the fuels used in the U.S. freight rail industry.
The DOE and the Federal Railroad Administration are contributing to the three-phase research project with $750,000 in research grants. The project started in 2022 and will be completed this year.
“There is a lot of rail interest today in alternative fuels as a means to reduce the impact from greenhouse gases,” said Michael Cleveland, director of Advanced Energy for Progress Rail. “Progress Rail is excited to be part of the evaluation of biodiesel and renewable diesel to support our customers’ sustainability-related goals.”
“This project is a great example of how collaboration between federal agencies and private industry can lead to innovative solutions for transportation sectors like rail,” said Douglas Longman, Argonne section manager, engine combustion research.
Argonne scientists will investigate biodiesel and renewable diesel fuel on a single-cylinder locomotive test engine provided by Progress Rail. Scientists will work at Argonne’s Engine Research Facility, which is home to two EMD® diesel locomotive test engines.
“More specifically, Progress Rail and Argonne will focus on the short-term challenges of biodiesel and renewable diesel blends and their impact on engine operation, performance and emissions,” said Essam El-Hannouny, an Argonne principal mechanical engineer. “The freight rail industry is limited in terms of tools to decarbonize its engines, and these fuels will play an important role in lowering the carbon intensity of the fleet.”
How high can biodiesel and renewable diesel blends go?
In the first phase of the project, Argonne scientists are using the Lab’s high performance computing resources provided by the Bebop cluster in Argonne’s Laboratory Computing Resource Center to create a modeling framework of different combustion systems that improve on existing models. In the second phase, scientists will use these models to build the single-cylinder engine to test at Argonne.
In the final phase, Argonne scientists will test a variety of bio- and renewable diesel fuels on the test engine’s operating cycle, measuring performance parameters including torque, power, engine thermal efficiency and exhaust emissions. Progress Rail is providing hardware and technical support throughout the project.
“The goal is to use the highest blends of bio- and renewable diesels without compromising engine performance,” said Munidhar S. Biruduganti, an Argonne principal research engineer. “If there is an impact, measures will be taken to modify engine hardware and operation to accommodate widespread adoption of these fuels. Lower-carbon fuels and engines work in tandem to reduce climate change while maximizing energy use.”
Progress Rail will use Argonne’s work to drive further performance and emissions optimization, enabling the efficient, reliable use of high percentage blends of lower energy content bio- and renewable diesel fuels. These upgrades would be extended to biofuel testing on multicylinder, high horsepower engines in locomotives used for hauling freight long distances.
Because locomotives have a service life of more than 30 years, the goal is to reduce CO2 impact from the existing fleet, keeping them in operation while alternative locomotive decarbonization technologies are explored.
Argonne’s testing builds on Progress Rail’s testing of alternative fuels. In 2021, Progress Rail approved the use up to 20% biodiesel blend for its EMD® 645 and 710 series engines. Previously, the locomotives were approved to operate at 5% biofuel.
“With over 26,000 freight locomotives currently in service globally, we were the first major locomotive manufacturer to endorse B20 across our existing fleet,” added Cleveland. “Progress Rail also leads the industry in alternative fuels, supporting global customers who run the highest fleet-wide blends of biodiesel in revenue service.”
Progress Rail has a long history of sustainability and is contributing to Caterpillar’s goal of reducing greenhouse gas (GHG) emissions by 30% from its operations by 2030.
Ultimately, the Argonne-Progress Rail project advances the freight rail industry’s multipronged strategy to reduce GHG emissions related to industry operations.
“The ultimate goal is to decarbonize the rail industry, and this project is a critical step in that direction,” said El-Hannouny.
Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation’s first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America’s scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.
The U.S. Department of Energy’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science.