Total global ethylene production is currently at 75 mln tons, leading to emission of millions of metric tons of greenhouse gases. A new environmentally friendly technology that may revolutionize the production of the world's most commonly produced organic compound has been created by scientists at the US Department of Energy's (DOE) Argonne National Laboratory.
An Argonne research team has devised a high-temperature membrane that can produce ethylene from an ethane stream by removing pure hydrogen. This is a clean, energy-efficient method of producing ethylene, production of which otherwise uses expensive and wasteful methods that emit a great deal of pollution. The new membrane reactor also performs an additional chemical trick confusing or cheating the thermodynamic limit: By constantly removing hydrogen from the stream, the membrane alters the ratio of reactants to products, enabling the reaction to make more ethylene than it theoretically could have before reaching equilibrium.
Because the new membrane lets only hydrogen pass through it, the ethane stream does not come into contact with atmospheric oxygen and nitrogen. This prevents 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. Unlike pyrolysis, which requires the constant input of heat, the hydrogen transport membrane produces the fuel needed in order to drive the reaction. By using air on one side of the membrane, the already-transported hydrogen can react with oxygen to provide energy.
Currently, the team has designed this experiment to prove the membrane's capability to produce ethylene, and hopes to extend the project by pairing with an industrial partner who would produce the membranes commercially. Since the membrane reduces the number of steps required to produce ethylene, the technology could enable the chemical to be produced more cheaply.