METHANATION FOR SYNTHETIC NATURAL GAS PRODUCTION – CHEMICAL REACTION ENGINEERING ASPECTS

The conversion of chemical energy carriers is in many cases either endothermic (e.g., steam reforming, gasification) or exothermic (e.g., combustions, hydrogenations). This chapter presents the most important feed gas compositions, the compositions to be expected after conversion according the thermodynamic equilibrium, the kinetics and reaction mechanisms of the main reactions, and important aspects of catalyst deactivation. It discusses methanation reactor types and their operation conditions. This chapter focuses on the modeling and simulation of methanation reactors. The most important aspect of experimentally determining chemical kinetics is the absence of physical limitations such as mass transfer and heat transfer. The possibility to raise high pressure steam and to generate thereby important economic synergies, favored the application of adiabatic fixed bed reactors for large scale coal to synthetic natural gas (SNG) plants. Depending on the hydrogen generation rate and the storage concepts, significant new challenges for the methanation reactors evolve.