Oxidative Coupling of Methane

Abstract

A quantitative comparison of the performance of the most common reactor con fi gurations proposed for the oxidative coupling of methane (OCM) is made on the basis of numerical calculations with phenomenological reactor models. The con fi gurations that are analyzed can be divided into two main categories, namely, packed-bed reactors (including conventional packed beds with external cooling, packed-bed membrane reactors, and adiabatic packed beds with post cracking) and fl uidized bed reactors (bubbling fl uidized bed reactor, circulating fl uidized bed reactor, and fl uidized bed membrane reactor). The challenges in both con-fi guration types, mainly the heat management in the case of the packed-bed reactors and the low C 2 þ yields obtained in fl uidized bed reactors, are evaluated and quanti fi ed. To ensure a fair comparison, La 2 O 3 /CaO is chosen as the OCM catalyst for all the considered cases, mainly in view of the availability of a comprehensive kinetics model. The results show that, with conventional con fi gu-rations, it is not possible to achieve high C 2 þ yields that are needed to make the process economically viable. However, the results also indicate that the C 2 þ yield can be signi fi cantly improved by feeding the oxygen distributively along the reactor axial length.