Preparation, Characterization, and Activity Evaluation of H-ZSM-5 Catalysts in Vapor-Phase Methanol Dehydration to Dimethyl Ether

• Published in: Industrial & engineering chemistry research Vol. 49; no. 9; pp. 4063 - 4069
• Main Authors: Hassanpour, Samaneh, Taghizadeh, Majid, Yaripour, Fereydoon
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 05.05.2010
• Subjects: Applied sciences; Catalysis; Catalytic reactions; Chemical engineering; Chemistry; Exact sciences and technology; General and physical chemistry; Kinetics, Catalysis, and Reaction Engineering; Reactors; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Dehydration; Preparation; Catalyst
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/ie9013869

Using the hydrothermal crystallization method, a highly crystalline series of H-ZSM-5 zeolites were prepared in different Si/Al molar ratios (ranging from 25 up to 250). The performance of prepared catalysts was a subject of assessment in the process of methanol dehydration to dimethyl ether (DME), where a stainless steel fixed-bed flow reactor at 573 K and 16 barg with WHSV of 26.5 h−1 was used. The catalysts were characterized by BET, XRD, NH3-TPD, ICP, TGA/DTA, TPH, and SEM techniques. According to the experimental results, the catalytic activity and surface acidity were increased with an increase in the Si/Al molar ratio up to 125 and then decreased. The sample with a Si/Al molar ratio of 125 [H-ZSM-5(125)] exhibited the best conversion and highest activity in methanol dehydration to DME. Before a comprehensive study was made on the synthesized zeolite catalysts, the dehydration reaction with crude methanol was studied over a commercial H-ZSM-5 catalyst under identical conditions. Results show that prepared catalysts have a better performance than commercial ones.