Direct Methane Conversion: An Industrial View

Abstract

Methane in natural gas can be converted to C1 products or hydrogen via “indirect” formation of synthesis gas for proven technology deployed in large-scale commercial projects. Direct conversion to C2+ products has not been commercialized due to lower yields, despite the potential to utilize a lower-cost feedstock. For future sustainable development, choosing direct conversion of natural gas must consider circularity of chemical products and supply chains. The alternative synthesis of chemicals from bio-based feedstocks or using carbon derived from direct air capture (DAC) of CO2 would allow direct incineration at end of life without increasing fossil CO2 footprints, whereas similar products derived from direct conversion of fossil-derived natural gas would require the addition of carbon capture and storage for end-of-life incineration. Direct conversion of lower concentrations of methane present in the refinery and process off-gas mixtures to C2+ products, as an alternative to combustion as process fuel, is an attractive proposition for reducing carbon footprints and improving circularity. Given the emerging role for hydrogen in decarbonizing industry and enabling zero emission vehicles in the transport sector, the direct conversion of methane to hydrogen and sequestered solid carbon products via methane pyrolysis is another potential use for direct methane conversion.