Oxidative coupling of methane using inorganic membrane reactors

摘要

The objective of this research is to study the oxidative coupling of methane in211u001ecatalytic inorganic membrane reactors. A specific target is to achieve conversion 211u001eof methane to C(sub 2) hydrocarbons at very high selectivity and higher yields 211u001ethan in conventional non-porous, co-feed, fixed bed reactors by controlling the 211u001eoxygen supply through the membrane. A membrane reactor has the advantage of 211u001eprecisely controlling the rate of delivery of oxygen to the catalyst. This 211u001efacility permits balancing the rate of oxidation and reduction of the catalyst. 211u001eIn addition, membrane reactors minimize the concentration of gas phase oxygen 211u001ethus reducing non selective gas phase reactions, which are believed to be a main 211u001eroute for the formation of CO(sub x) products. Such gas phase reactions are a 211u001ecause of decreased selectivity in the oxidative coupling of methane in 211u001econventional flow reactors. Membrane reactors could also produce higher product 211u001eyields by providing better distribution of the reactant gases over the catalyst 211u001ethan the conventional plug flow reactors. Membrane reactor technology also offers 211u001ethe potential for modifying the membranes both to improve catalytic properties as 211u001ewell as to regulate the rate of the permeation/diffusion of reactants through the 211u001emembrane to minimize by-product generation. Other benefits also exist with 211u001emembrane reactors, such as the mitigation of thermal hot-spots for highly 211u001eexothermic reactions such as the oxidative coupling of methane. The application 211u001eof catalytically active inorganic membranes has potential for drastically 211u001eincreasing the yield of reactions which are currently limited by either 211u001ethermodynamic equilibria, product inhibition, or kinetic selectivity.