Synthesis of dimethyl ether and isoparaffins from syngas over capsule catalysts

Abstract

In this thesis, the experiment is divided into two parts. The first part studied was dimethyl ether synthesis and was prepared the new capsule catalysts by a direct hydrothermal synthesis method which directly synthesized H-ZSM-5 membrane was coated completely onto Cr/ZnO catalyst pellets. The dehydration of methanol to dimethyl ether over Cr/ZnO capsule catalysts was also investigated in this study. All catalysts have been characterized and were identified by SEM, EDS and XRD. The experiment was carried out at 573, 598 and 623 K, 5 MPa, W/F = 13.6 g.h/mol, in a fixed bed reactor. It was found that the capsule catalysts have shown better performance compared to the physical mixing catalysts. Particularly, capsule catalysts were indicated higher dimethyl ether selectivity, and showed selectivity of dimethyl ether with 45.33 % at 598 K. In addition, the performance of catalyst was operated at 573 K, 4 MPa with a slurry phase reactor and was compared with the conventional FTS catalyst(Cr/ZnO) and physically mixed catalysts. The second part studied the synthesis of isoparaffins and synthesized H-beta zeolite membrane coated Co/Al2O3 core/shell catalyst by hydrothermal method.