A new kind of power plant that doesn’t add greenhouse gases to the atmosphere is being built in the U.S., potentially providing a way for utilities to keep burning natural gas without contributing to global warming. Net Power intends to build two natural-gas power plants in the U.S. that will have all its emissions captured and buried deep underground. The startup licensed its technology to developer 8 Rivers Capital LLC, which will work with agriculture giant Archer-Daniels-Midlands Co. to replace some emissions from a coal power plant in Illinois.
For the other plant, 8 Rivers is working with the Southern Ute Indian Tribe Growth Fund in Colorado. Both projects will be designed and developed this year, which 8 Rivers says requires spending tens of millions of dollars. A final decision on whether to go ahead with the facilities is due in 2022. Net Power’s technology uses a new kind of turbine to burn natural gas in oxygen, rather than the air. As a result, the plant only produces carbon dioxide and water as a byproduct. The water can be frozen out of the mixture and the pure stream of CO₂ can be buried in depleted oil and gas wells or similar geological structures.
The required oxygen is secured by separating it from the air, which needs energy. But Net Power says its turbine is more efficient so that, on balance, the overall efficiency of the system matches that of an advanced natural-gas power plant that pumps its emissions into the atmosphere. Another upside of using oxygen is that Net Power plants do not produce any nitrogen emissions, which would cause local air pollution.