A patented technology from The National Energy Technology Laboratory (NETL), part of the U.S. Department of Energy (DOE) national laboratory system, offers a cost-effective way to separate carbon dioxide (CO2) and hydrogen sulfide (H2S) from hydrogen (H2), carbon monoxide, (CO), and nitrogen (N2) – enabling low-carbon electricity generation and efficient fuel processing.

This technology is a physical solvent that selectively removes weak acid gases, such as CO2, from high-pressure gas streams composed of CO2 and H2, such as those found in carbon capture, H2 purification, and natural gas sweetening applications. What makes NETL’s solvents unique is its ability to use waste heat rather than electricity to drive the solvent’s regeneration. This translates to cost savings realised by increased efficiency.

Commercial technologies currently on the market must operate at cooler temperatures (+10 to -10 degrees Celsius), requiring additional energy for the solvents to be chilled and regenerated for further use. NETL’s solvent can operate at higher temperatures (above room temperature) and use waste heat to regenerate. This means chemical plants, power plants, refineries, among others using the solvent can reduce their cost of capturing CO2 from these sources. Using waste heat can increase the amount of net electricity production by up to 50 MW at a 500 MW-scale power plant with CO2 capture.

”We’re optimistic this solvent can make an impact in a wide range of markets enabling cleaner, more efficient energy production.”

NETL inventor Nicolas Siefert, Ph.D

This technology overcomes typical issues with high vapour pressure, water sorption, and poor selectivity associated with other physical solvents for CO2 capture. All commercially available physical solvents used in such separation processes are hydrophilic and have high vapour pressure, requiring operation of the process below room temperature.

NETL inventor Nicolas Siefert, Ph.D., explains the novel solvent can be tailored to a variety of energy applications. He said, “We anticipate our technology to be highly effective for pre-combustion CO2 capture, H2 generation from reformed natural gas, and removing CO2 from syngas for coal and biomass to ammonia and fertiliser. There are also a range of potential markets including natural gas sweetening, ethane cracking, and landfill gas and biogas upgrading. We’re optimistic this solvent can make an impact in a wide range of markets enabling cleaner, more efficient energy production.”

NETL is currently seeking a third party to license the technology and work with the Lab’s researchers to continue development, with the ultimate goal of creating a commercially viable cost-effective technology that reduces the cost of separating weak acid gases from fuel gas streams at power plants and chemical plants.

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