%0 Journal Article
%T Thermodynamic Equilibrium Analysis of Methanol Conversion to Hydrocarbons Using Cantera Methodology
%A Duminda A. Gunawardena
%A Sandun D. Fernando
%J Journal of Thermodynamics
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/125460
%X Reactions associated with removal of oxygen from oxygenates (deoxygenation) are an important aspect of hydrocarbon fuels production process from biorenewable substrates. Here we report the equilibrium composition of methanol-to-hydrocarbon system by minimizing the total Gibbs energy of the system using Cantera methodology. The system was treated as a mixture of 14 components which had CH3OH, C6H6, C7H8, C8H10 (ethyl benzene), C8H10 (xylenes), C2H4, C2H6, C3H6, CH4, H2O, C, CO2, CO, H2. The carbon in the equilibrium mixture was used as a measure of coke formation which causes deactivation of catalysts that are used in aromatization reaction(s). Equilibrium compositions of each species were analyzed for temperatures ranging from 300 to 1380£¿K and pressure at 0¨C15 atm gauge. It was observed that when the temperature increases the mole fractions of benzene, toluene, ethylbenzene, and xylene pass through a maximum around 1020£¿K. At 300£¿K the most abundant species in the system were CH4, CO2, and H2O with mole fractions 50%, 16.67%, and 33.33%, respectively. Similarly at high temperature (1380£¿K), the most abundant species in the system were H2 and CO with mole fractions 64.5% and 32.6% respectively. The pressure in the system shows a significant impact on the composition of species. 1. Introduction Methanol is the simplest alcohol which has a tremendous importance as an industrial feedstock [1, 2]. As a fuel, methanol does not have high enough specific heat value to compete with gasoline and therefore its not attractive as a substitute but as a motor fuel additive it is said to be improving the fuel quality. The prospect of methanol being used as raw material for fuel processing actually started with the accidental discovery by Chang and Silvestry in the early 70s [3]. With the use of newly discovered ZSM-5 it was found that methanol can be transformed to gasoline grade products. Methanol conversion process in the industry has branched into two paths, namely, methanol to olefins (MTO) and methanol to gasoline (MTG). Even though MTG got the global attention as an alternative route to produce fuel, it was unable to make the process economically viable [4, 5]. To make the process economical the process parameters has to be optimized. Catalyst upgrading to make deoxygenation reaction more selective toward gasoline products such as benzene, toluene, ethylbenzene, and xylene (BTEX) is one such approach [6, 7]. Another approach is to alter the reaction conditions such as temperature, pressure, and residence time to augment the desired product spectrum [6, 8]. For
%U http://www.hindawi.com/journals/jther/2012/125460/