Feasibility study on the co-generation of ethylene and electricity through oxidative coupling of methane

Ethylene is the most important base chemical in the petrochemical industry. One alternative route for the production of ethylene is from natural gas via oxidative coupling of methane. So far the process is economically unfeasible. However, recent studies suggest that this may be overcome by producing not only ethylene but also electricity, using the heat from the very exothermic coupling reaction. In this work we have compared this co-generation scheme with a scheme in which ethylene (106 kt/y) and electricity (44 MW) are generated separately by conventional processes in the Netherlands. It was concluded that: Energy savings are probably not significant. CO2 emissions are reduced significantly. Also, since the CO2 is obtained as a pure by-product, it may be feasible to reduce these emissions to zero. Costs: co-generation has a rather low profitability, lower than that of the conventional scheme. Furthermore, a number of alternatives to improve the co-generation scheme have been examined. The most promising (long-term) alternative to the fluidised-bed reactor for the oxidative coupling of methane is an oxygen-permeable membrane reactor, which by eliminating the need for an oxygen plant could give significant improvements in terms of energy efficiency, CO2 emissions, and costs. This could make the cogeneration scheme a viable option. (C) 2004 Elsevier Ltd. All rights reserved.