The catalytic oxidation of methane to useful products
This project has concentrated on gaining an understanding of the factors influencing the behaviour of various catalyst systems for the oxidative coupling of methane. Systems studied have included PbO/Al(2)O(3), Li/MgO, various rare earth oxides and BaCO(3)/CaO. Particular attention has been given to the Li/MgO system. It is shown that the active phase in such catalysts is derived from Li(2)CO(3) species, and that the lifetime of such systems can be prolonged by adding CO(2) to the feed to the reactor. Considerable improvements in yield can be achieved by paying attention to the reactor construction and reaction conditions. It has been shown that further considerable improvements in the Li/MgO catalyst system can be achieved by adding various oxides to the formulation, the most promising of these being SnO(2) and CoO. The Li/Sn/MgO system is very stable and it can be used at relatively low temperatures, when gas-phase processes are much less important. Detailed investigation of the reaction network over the different catalyst systems has shown that the sequence: CH(4) to C(2)H(6) to C(2)H(4) to CO(x) is predominant over the Li/MgO and doped Li/MgO systems. A parallel route to CO(x) (i.e. directly from CH(4)) is important for many of the other catalyst systems, and is responsible for lower selectivities over these systems. It is concluded that, in future, most attention should be given to developing stable low-temperature catalysts. Under these conditions, there is a higher chance of obtaining the high C(2) yields needed for a commercial application of oxidative methane coupling.
Bibliographic Reference: EUR 13767 EN (1991) 144 pp., FS, ECU 12.50
ISBN: ISBN 92-826-3217-2
Record Number: 199111531 / Last updated on: 1994-12-02
Original language: en
Available languages: en