Methanol from Natural Gas by the Lurgi Combined Reformining Process

In addition to conventional natural gas steam reforming processes for methanol that are licensed by various companies (mainly ICI of the U.K. and Lurgi of West Germany), Lurgi also offers a variant called the "Combined Reforming Process." This process uses a combination of primary steam reforming with secondary oxygen reforming for the generation of syngas. Compared with conventional steam reforming, which produces a hydrogen rich syngas, the combined reforming process furnishes syngas that is close to stoichiometric--which results in an increased energy efficiency. Other advantages of the combined reforming approach include a smaller primary reformer that operates at milder conditions and a reduced compression horsepower. These advantages are offset by the need for an air separation plant to generate the oxygen for secondary reforming.

In this review we evaluate the Lurgi Combined Reforming Process and compare its economics with a conventional steam reforming process, such as the ICI process. Data for the latter are taken from our PEP Report 148 (Section 4, pp. 47-71). Our evaluation shows that the costs for the two processes are quite close. Although the Lurgi process requires lower capital investment costs for the primary reforming, syngas compression, and methanol synthesis stages, this is offset by the need for an air separation plant. Thus, the total fixed capital costs for the two processes are almost identical and the main difference is the slightly lower (3.3%) energy consumption for the Lurgi process.