Methane is predominantly known as a potent greenhouse gas – but methane is also the primary component of natural gas, the cleanest-burning hydrocarbon fuel. Environmentally speaking, letting methane escape is a major problem… but burning it? Not as much. Keeping the gas safely trapped during processes like natural gas extraction or combustion, therefore, is a major priority for energy researchers. Now, researchers from Montana State University and Oak Ridge National Laboratory have leveraged the Comet supercomputer to advance our understanding of how methane is adsorbed.
Specifically, the researchers studied methane adsorption by a type of porous carbon called zeolite-templated carbon (ZTC). Porous carbon possesses a number of qualities – such as structural tunability – that make it a popular choice for materials scientists. The team modeled a series of ZTC “maquettes” (surface sites), allowing them to then calculate methane gas’ binding energy.
To run these heavy-duty models, the researchers turned to high-performance computing. On-site HPC resources – including the 22 peak petaflops Hyalite cluster at Montana State University – were complemented by the San Diego Supercomputer Center (SDSC), which delivers 2.76 peak petaflops via 1,944 Intel Haswell-based CPU nodes and 72 Nvidia-based GPU nodes. The team obtained access to Comet via the Extreme Science and Engineering Discovery Environment (XSEDE).
“The additional computational resources provided by the XSEDE allocation allowed us to complete a more thorough study, including computational control and blank simulations, which are mandatory for experimental work but are often omitted in theoretical studies,” said Robert K. Szilagyi, an associate professor of chemistry and biochemistry at Montana State University, in an interview with SDSC’s Kimberly Mann Bruch.
“Access to a high-performance computational facility, where users do not need to worry about how to maintain hardware, compile software, and tune executions, allows for experimentalists to harness the power of computational chemistry as an independent and routine research tool in their laboratory,” added Nicholas P. Stadie, an assistant professor of physical chemistry and materials science at the university.
Szilagyi explained that the simulations helped the researchers deduce that nitrogen-doped carbon materials showed significantly stronger methane gas adsorption properties.
“From a comprehensive set of calculations, we clearly identified the preference of methane toward nitrogen-substituted adsorption sites,” he said, explaining that the team was “really surprised by the clear and consistent preference for methane toward nitrogen-substituted porous carbon models” – a preference that went against the grain of prevailing materials theory.
Szilagyi said that the research “[validates] the use of computational chemistry as a tool to design new porous carbon materials for methane storage applications – a key bridging technology to reduced-carbon or carbon-neutral chemical fuels for vehicles.”