Carbon Dioxide Conversion in High Temperature Reactions

This chapter deals with high temperature reactions in which carbon dioxide (CO2) is used either as dehydrogenation agent (“soft oxidant”) or hydrogen user (“reduction to other C1 molecules”). The first part of the chapter covers reactions such as the oxidative coupling of methane, the dehydrogenation of alkanes to olefins, the dehydrogenation of ethylbenzene to styrene, and, finally, CO2 reforming of methane. The second part covers the reaction of CO2 with hydrogen in processes such as the reverse water gas shift reaction and the synthesis of both methanol and dimethyl ether. All processes discussed here already have an industrial exploitation or are related to processes on stream, so that a large set of data is available in the literature. This chapter illustrates the building-up of knowledge for demonstrating the reaction mechanism in processes in which very often several conversion routes of CO2 coexist and the role of support and catalysts is essential for addressing the reaction in one or another direction.