An application of a Pd-based membrane in a multistage spherical styrene monomer production process for hydrogen extraction

Abstract

One of the main processes in the petrochemical industry is the dehydrogenation of ethylbenzene (EBDH). The process suffers from some practical deficiencies, the most important of which is limitation of conversion progress due to the reversible main reaction. Therefore, the use of spherical membrane reactors (SMR) to carry out the EBDH process is proposed. This paper presented a metal-based hydrogen permselective membrane layer that could mitigate the limitations associated with conventional tubular reactors (CTRs). In the new configuration, pure hydrogen was produced and ethylbenzene conversion was improved, resulting in a reduction in separation and purification costs. In addition, co-current and countercurrent flows were compared to evaluate the performance of the system. Based on the proposed structure, EB conversion, and SM yield were improved by approximately 23% and 15.9%, respectively, over CTRs. As a result of the spherical membrane EBDH, at least 60% of the produced hydrogen gases could be separated from the catalytic bed, resulting in a hydrogen-rich stream.