Chloromethane Conversion to Higher Hydrocarbons over Zeolites and SAPOs
- PDF / 189,744 Bytes
- 5 Pages / 593.972 x 792 pts Page_size
- 78 Downloads / 189 Views
Catalysis Letters Vol. 109, Nos. 1–2, June 2006 (Ó 2006) DOI: 10.1007/s10562-006-0063-5
Chloromethane conversion to higher hydrocarbons over zeolites and SAPOs Dazhi Zhang,a,c Yingxu wei,a Lei Xu,a Aiping Du,a,c Fuxiang Chang,a,c Bao-lian Su,b and Zhongmin Liua,* a
Natural Gas Utilization and Applied Catalysis Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, P.O. Box 110, Dalian 116023, P.R. China b Laboratoire de Chimie des Mate´riaux Inorganiques (CMI), The University of Namur (FUNDP), B-5000 Namur, Belgium c Graduate school of the Chinese Academy of Sciences, Beijing 100039, P.R. China
Received 4 January 2006; accepted 26 January 2006
Chloromethane transformations were carried out over zeolites and SAPOs and the conversion and product distribution differed from the porous structure and acidity of the catalysts. Chloromethane was mainly transferred to higher hydrocarbons in gasoline range over most of zeolite catalysts, while SAPOs molecular sieves, SAPO-34 and SAPO-5, showed high selectivity for light olefins production, such as ethylene, propylene and butenes. TG analysis was used to study the coke formation during the transformation and the acid difference of the catalysts was evidenced by Temperature programmed desorption of ammonia. HZSM-5, with high activity and less coke formation, was proved to be a potential catalyst for hydrocarbons production from chloromethane conversion. It is of particular interest that SAPO-34 gave an excellent performance in light olefins production from chloromethane transformation, which may be attributed to the shape selectivity and medium strong acidity of SAPO-34. KEY WORDS: Chloromethane transformation; ZSM-5; SAPO-34; higher hydrocarbons; light olefins.
1. Introduction Methane transformation to more useful higher hydrocarbons is one of the most important topics of natural gas utilization. During the past decades, although methane activation and its direct conversion to valuable compounds draw increasing attention, the successful processes are still in indirect pathway. Methane is transformed to syngas by partial oxidation or reforming, followed by a conversion to higher hydrocarbons using Fischer-Tropsch technology [1, 2]. In another process, syngas is converted firstly to methanol using Cu/ZnO/ Al2O3 catalysts and then to hydrocarbons with MTG or MTO catalyst [3–6]. Even the Fischer-Tropsch process can produce higher hydrocarbons from syngas, the products always appeared in a long range. The complication of these routes also limits their economic interests. The development of alternative routes for higher hydrocarbon production through methane transformation attracts much attention from industry and academia. In 1985, Olah et al. [7] reported a three-step process that methane could be converted to hydrocarbons via methyl halide. In his study methane could be directly converted to chloromethane by reacting with chlorine or hydrogen chloride and oxygen, then the produced chloromethane can be converted to hydrocarbons over ze
Data Loading...
