Colorado State University leaders in natural gas engine design and optimization are among a handful of teams nationwide innovating new technologies for reducing greenhouse gas emissions in oil, gas and coal industries.
Researchers led by Daniel Olsen, professor in the Department of Mechanical Engineering, and Bret Windom, associate professor in the same department, are among 12 teams receiving a total of $35 million in research funding from the Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E). The funding program supports research in reducing emissions of methane, a greenhouse gas 25 times more potent than carbon dioxide. The projects support the U.S. Methane Emissions Reduction Action Plan, announced at the 2021 United Nations Climate Change Conference.
The CSU researchers received a $1.5 million grant for work to reduce emissions from four-stroke, lean-burn natural gas engines typically found at compressor stations between natural gas wellheads and large interstate pipelines that carry the gas across long distances. In particular, they are seeking to design a system to reduce methane normally emitted from the engine’s crankcase.
The crankcase is the part of the engine where the crankshaft spins. Small amounts of gas from the engine cylinder – fuel, air, and combustion products – can leak past the piston rings and into the crankcase. Typically, these gases, including methane, build up in the crankcase and are vented into the atmosphere. The venting is part of the engine’s design, preserving its life and ensuring reliability in the field. However, resulting methane emissions are a significant industry problem and one that the CSU researchers think they can solve. According to some estimates, crankcase methane emissions account for 20% or more of total methane emissions from such engine systems.
The researchers’ plan is to develop a system that recaptures the crankcase ventilation gas, filters it, and reroutes it back into the engine. It would be a bit like exhaust gas recirculation systems found in many vehicles, in which exhaust gas is rerouted to reduce oxides of nitrogen (NOx) emissions.
“The methane normally vented into the atmosphere would instead be burned by the engine,” explained lead researcher Olsen, who directs the Energy Institute’s Engines and Energy Conversion Laboratory, where the research will take place. Their goal is to reduce methane emissions from crankcase gas by over 75%.
The CSU team is the only one among those funded by the ARPA-E program focusing on the particular problem of crankcase emissions.
“We think this is a solvable problem that will definitely put a dent in methane emissions in the natural gas industry,” Windom said.
Partnership with Caterpillar
The team is partnering with Caterpillar, a leading manufacturer of natural gas engines, who will donate a 52 Liter, 1,035 horsepower lean-burn natural gas research engine (Cat® G3512J) that will reside at the Powerhouse Energy Campus at CSU. The research team includes Caterpillar engineers David Montgomery and David Ginter.
The Cat® engine will arrive at Powerhouse later this year, and the researchers will spend the next year and a half designing and testing their crankcase gas rerouting system. If additionally funded, they will then test their system at a gas compression site in the Denver-Julesburg basin in Colorado.