A new method of making ethylene that prevents greenhouse gas emissions has been created by scientists at the U.S. Department of Energy's Argonne National Laboratory. The clean, energy-efficient way of producing ethylene involves a high-temperature membrane that can produce ethylene from an ethane stream by removing pure hydrogen. The new membrane lets only hydrogen pass through it, hence the ethane stream does not come into contact with atmospheric oxygen and nitrogen, preventing the creation of a miasma of greenhouse gases - nitrogen oxide, carbon dioxide and carbon monoxide - associated with the traditional production of ethylene by pyrolysis, in which ethane is exposed to jets of hot steam. The new membrane reactor performs an additional chemical trick by constantly removing hydrogen from the stream. In this way, the membrane enables the reaction to make more ethylene that it theoretically could have before reaching equilibrium.