Methane to Liquid Fuels over Metal Loaded HZSM-5 Catalyst

Abstract

ZSM-5 zeolite is an acidic catalyst that is highly potential for the conversion of natural gas to liquid fuels. One of the variables that controls the acidity of the ZSM-5 is its Si/Al ratio. Loading the ZSM-5 zeolite with transition metals produces a catalyst with dual function – acidic and oxidative. These two functions need to be balanced to promote certain reactions such as dehydrogenation and oligomerization and to suppress the combustion reaction. The purpose of this study is to modify the ZSM-5 zeolite by substitution of aluminium in the zeolitic framework with an oxidative element, and test its performance for the conversion of methane to liquid fuels. Metal loaded dealuminated ZSM-5 zeolite was prepared by the acidic ion exchange method. Cr, Cu and Ga were chosen based on their role as a metal-oxide catalyst in reforming and dehydrogenation processes. The oxidation of methane was carried out in a micro-packed bed reactor at atmospheric pressure, 800°C, F/W = 10440 ml/g.hr and 9 vol% O2. The experimental results indicated that methane oxidation over the metal loaded dealuminated ZSM-5 produced gasoline with an encouraging Research Octane Number. The conversion of methane and the selectivity of gasoline obtained demonstrate that these catalysts have the potential to convert methane to C5+ liquid hydrocarbons.