Making methane from CO2: carbon capture grows more affordable

In Washington, in their ongoing effort to make carbon capture more affordable, researchers at the Department of Energy’s Pacific Northwest National Laboratory have developed a method to convert captured carbon dioxide (CO2) into methane, the primary component of natural gas. By streamlining a longstanding process in which CO2 is converted to methane, the researchers’ new method reduces the materials needed to run the reaction, the energy needed to fuel it and, ultimately, the selling price of the gas.

A key chemical player known as EEMPA makes the process possible. EEMPA is a PNNL-developed solvent that snatches CO2 from power plant flue gas, binding the greenhouse gas so it can be converted into useful chemicals.

Earlier this year, PNNL researchers revealed that using EEMPA in power plants could slash the price of carbon capture to 19 percent lower than standard industry costs—the lowest documented price of carbon capture. Now, the team reveals a new incentive—in cheaper natural gas—to further drive down costs.

When compared to the conventional method of methane conversion, the new process requires an initial investment that costs 32 percent less. Operation and maintenance costs are 35 percent cheaper, bringing the selling price of synthetic natural gas down by 12 percent.