An environmentally friendly configuration for reduction of toxic products in a thermally coupled reactor of styrene and tri-reformer of methane

Abstract

The aim of this work is a comparison of different hydrogen permeation membranes in a thermally coupled membrane reactor in producing two precious chemicals, hydrogen and styrene. A thermally coupled membrane reactor is designed as a double pipe reactor where methane tri-reforming for hydrogen production is considered in exothermic side of reactor and styrene production reaction takes place in endothermic side. The walls of the shell side are coated by the layers of hydrogen perm-selective membrane. The produced hydrogen in the endothermic side is transferred to the permeation side, while the generated heat in the exothermic side is transferred to the endothermic section. The reactor performance is theoretically investigated in the presence of six types of hydrogen perm-selective membranes which are stable at operating conditions. Results are compared with each other and it is concluded that the highest hydrogen permeation rate (maximum 0.6mol/s) is achieved in VCr4Ti4 membrane named as TCMR5. Therefore, it leads to the highest ethylbenzene conversion (98%) and styrene production yield (95%) in the endothermic side as well as methane conversion (98.5%) in the exothermic side. Furthermore, toxic materials such as benzene and toluene decrease to about 66% and 46% in TCMR5 rather than the conventional reactor. Consequently, the fifth thermally coupled membrane reactor encoded TCMR5 is an environmentally friendly configuration than others.