Steam cracking and natural gas to olefins

Abstract

Steam cracking for the production of light olefins (e.g. ethylene and propylene) is the single most energy consuming process in the chemical industry. Production of light olefins from natural gas is possible through different routes. This paper compares the cumulative energy use and CO2 emissions of some of these routes (methanol-to-olefins, methanol-to-propylene and oxidative coupling of methane via ethane) with those of naphtha and ethane-based steam cracking. One conclusion is that the most efficient natural gas-to-olefms-via-methanol uses more than twice as much primary energy as state-of-the-art steam cracking to produce one ton of high value chemicals. This is largely due to high energy use in methanol production. Another conclusion is oxidative coupling of methane via ethane routes could have low CO2 emissions if more recycling is used and less electricity is co-generated.