Analysis and simulation of reactive distillation for gasoline alkylation desulfurization

The increasingly stringent regulations on sulfur content in fuel require refineries to develop new desulfurization processes. Through the alkylation of thiophene and its derivatives with olefins followed by distillation, alkylation desulfurization is an alternative technology in the case of gasoline for its mild operation conditions and low loss of octane number. In this paper, the application of reactive distillation in gasoline alkylation desulfurization is studied, including a conceptual design and a rigorous steady state simulation. The conceptual design considers three aspects: thermodynamic analysis of the reactive system, benefits and constraints of the reactive distillation, and computation of the reactive residue curve maps. Results show that reactive distillation is feasible for gasoline alkylation desulfurization, and it has no constraints but great potential for its capital savings, improved conversion, reduced by-product formation, improved catalyst stability and avoidance of hot spots. The simulation results show that reactive distillation could obtain product gasoline with sulfur content less than 1 ppmw. It is shown that reactive distillation may be considered a viable technological alternative for gasoline alkylation desulfurization. (C) 2012 Elsevier Ltd. All rights reserved.