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J Hazard Mater

Title:		Combustion of chlorinated volatile organic compounds (VOCs) using bimetallic chromium-copper supported on modified H-ZSM-5 catalyst
Author(s):		Abdullah AZ; Bakar MZ; Bhatia S;
Address:		"School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, Seri Ampangan, Nibong Tebal, 14300 Pulau Pinang, Malaysia. chzuhairi@eng.usm.my"
Journal Title:		J Hazard Mater
Year:		2006
Volume:		20051128
Issue:		1-Mar
Page Number:		39 - 49
DOI:		10.1016/j.jhazmat.2005.05.051
ISSN/ISBN:		0304-3894 (Print) 0304-3894 (Linking)
Abstract:		"The paper reports on the performance of chromium or/and copper supported on H-ZSM-5(Si/Al = 240) modified with silicon tetrachloride (Cr1.5/SiCl4-Z, Cu1.5/SiCl4-Z and Cr1.0Cu0.5/SiCl4-Z) as catalysts in the combustion of chlorinated VOCs (Cl-VOCs). A reactor operated at a gas hourly space velocity (GHSV) of 32,000 h(-1), a temperature between 100 and 500 degrees C with 2500 ppm of dichloromethane (DCM), trichloromethane (TCM) and trichloroethylene (TCE) is used for activity studies. The deactivation study is conducted at a GHSV of 3800 h(-1), at 400 degrees C for up to 12 h with a feed concentration of 35,000 ppm. Treatment with silicon tetrachloride improves the chemical resistance of H-ZSM-5 against hydrogen chloride. TCM is more reactive compared to DCM but it produces more by-products due to its high chlorine content. The stabilization of TCE is attributed to resonance effects. Water vapor increases the carbon dioxide yield through its role as hydrolysis agent forming reactive carbocations and acting as hydrogen-supplying agent to suppress chlorine-transfer reactions. The deactivation of Cr1.0Cu0.5/SiCl4-Z is mainly due to the chlorination of its metal species, especially with higher Cl/H feed. Coking is limited, particularly with DCM and TCM. In accordance with the Mars-van Krevelen model, the weakening of overall metal reducibility due to chlorination leads to a loss of catalytic activity"
Keywords:		"Air Pollutants, Occupational/*chemistry Catalysis Chromium Compounds/chemistry Copper *Incineration Organic Chemicals/*chemistry Volatilization;"
Notes:		"MedlineAbdullah, Ahmad Zuhairi Bakar, Mohamad Zailani Abu Bhatia, Subhash eng Research Support, Non-U.S. Gov't Netherlands 2005/11/29 J Hazard Mater. 2006 Feb 28; 129(1-3):39-49. doi: 10.1016/j.jhazmat.2005.05.051. Epub 2005 Nov 28"