ExxonMobil is proposing a plant in Houston that would produce close to 800,000 m3 per day of blue hydrogen from natural gas. To make the H2 blue, the firm would capture the carbon dioxide by-product and permanently store it underground. ExxonMobil tells C&EN that the CO2 would not be used for enhanced oil recovery. The firm plans to use the H2 as a feedstock for olefins and other chemicals, which would then be considered low-carbon alternatives. The project is part of a planned multiparty hub for carbon capture and storage that ExxonMobil has proposed for the Houston area.