Effect of alkaline treatment on pore structure and acidity of HZSM-5 in the synthesis of ethyl mercaptan

Advances in Resources Recovery of H2S: A Review of Desulfurization Processes and Catalysts

“…The content of CH 3 CH 2 SH can reach 90% without refinement, which can be directly used for the synthesis of pesticides. So far, Lewis acid catalysts, molecular sieve catalysts, ion-exchange resins, and transition metal sulfide catalysts have all been used to prepare ethanethiol by the C 2 H 4 -H 2 S process . For example, Bernard et al reported the synthesis of CH 3 CH 2 SH by using Na 2 MoO 4 /Al 2 O 3 and K 2 WO 4 /Al 2 O 3 catalysts .…”

“…This means that the energy consumption of the reaction is high, which is not conducive to industrial production. Zhang et al studied the effect of alkaline treatment on pore structure and acidity of HZSM-5 (SiO 2 /Al 2 O 3 = 135) in the synthesis of ethyl mercaptan . The mesopores in HZSM-5 were formed by desilication in an alkaline solution, which selectively removed the silicon species from zeolite crystals and effectively generated two hierarchical pore systems.…”

“…So far, Lewis acid catalysts, molecular sieve catalysts, ion-exchange resins, and transition metal sulfide catalysts have all been used to prepare ethanethiol by the C 2 H 4 -H 2 S process. 291 292 When the proportion of each component is appropriate, the yield of ethyl mercaptan can reach up to 78%. The catalyst could be used continuously for more than 100 h without deactivation.…”

“…Zhang et al studied the effect of alkaline treatment on pore structure and acidity of HZSM-5 (SiO 2 /Al 2 O 3 = 135) in the synthesis of ethyl mercaptan. 291 The mesopores in HZSM-5 were formed by desilication in an alkaline solution, which selectively removed the silicon species from zeolite crystals and effectively generated two hierarchical pore systems. As a result, the DS-1 sample exhibited 89.2% ethylene conversion and 93.8% CH 3 CH 2 SH selectivity at the conditions of 1.4 MPa, 513 K, a GHSV of 240 h −1 , and a molar ratio of H 2 S to C 2 H 4 of 3:1.…”

Strategies to Enhance the Catalytic Performance of ZSM-5 Zeolite in Hydrocarbon Cracking: A Review

“…The silicon is selectively dissolved by NaOH treatment to generate substantial mesoporosity. The catalytic performance and catalytic lifetime can be effectively enhanced by this post-treatment method [77][78][79]88,89]. After alkali treatment, although more carbon deposited on ZSM-5 zeolite in n-hexane cracking, it showed smaller deactivation rate due to the increased external surface area, mesopore volume and pore mouth, which made ZSM-5 zeolite less sensitive to carbon deposition [90].…”