The Hy-C process (thermal decomposition of natural gas): Potentially the lowest cost source of hydrogen with the least CO{sub 2} emission

Abstract

The abundance of natural gas as a natural resource and its high hydrogen content make it a prime candidate for a low cost supply of hydrogen. The thermal decomposition of natural gas by methane pyrolysis produces carbon and hydrogen. The process energy required to produce one mol of hydrogen is only 5.3% of the higher heating value of methane. The thermal efficiency for hydrogen production as a fuel without the use of carbon as a fuel, can be as high as 60%. Conventional steam reforming of methane requires 8.9% process energy per mole of hydrogen even though 4 moles of hydrogen can be produced per mole of methane, compared to 2 moles by methane pyrolysis. When considering greenhouse global gas warming, methane pyrolysis produces the least amount of CO{sub 2} emissions per unit of hydrogen and can be totally eliminated when the carbon produced is either sequestered or sold as a materials commodity, and hydrogen is used to fuel the process. Conventional steam reforming of natural gas and CO shifting produces large amounts of CO{sub 2} emissions. The energy requirement for non-fossil, solar, nuclear, and hydropower production of hydrogen, mainly through electrolysis, is much greater than that from natural gas. From the resource available energy and environmental points of view, production of hydrogen by methane pyrolysis is most attractive. The by-product carbon black, when credited as a saleable material, makes hydrogen by thermal decomposition of natural gas (the Hy-C process) potentially the lowest cost source of large amounts of hydrogen.