Sergei Yurchak

Mobil Methanol-to-Gasoline Process

This paper explains that 2 major concerns in the development of the methanol-to-gasoline (MTG) process are heat removal from the reactor and the formation of durene (1-,2-,4-,5-tetramethylbenzene). Conversion of methanol to gasoline is highly exothermic (about 1510-1740 kJ/kg of methanol converted) and the adiabatic temperature rise would be almost 600C. Within Mobil, 2 types of reactor configurations were adopted for development: an adiabatic fixed-bed and a fluid-bed reactor. The fixed-bed reactor is ready for immediate commercialization and is more suitable for smaller scale operation. The fluid-bed reactor is under development and possesses the following potential advantages over the fixed-bed reactor: reaction heat removal is simplified by using the superior heat transfer characteristics of a fluid bed; when coupled with alkylation, the fluid bed gives a higher gasoline yield than the fixed bed; and constant catalyst activity, gasoline selectivity, and gasoline quality can be maintained with the fluid-bed operation. Fixed-bed is cyclic.