Integrated aqueous-phase glycerol reforming to dimethyl ether synthesis A novel allothermal dual bed membrane reactor concept

Dimethyl ether (DME) production from glycerol via an integrated process involving aqueous-phase glycerol reforming to biosyngas combined with DME synthesis into an allothermal dual-bed membrane reactor was analyzed numerically. The system combines two separate enclosures, a fixed-bed water perm-selective membrane DME synthesis unit and a gas-liquid-solid fixed-bed aqueous-phase glycerol reforming unit. Exothermic DME synthesis provides heat to endothermic aqueous-phase glycerol reforming which in return produces biosyngas for DME synthesis. The two-scale, non-isothermal, unsteady-state model developed for the integrated system accounts for a detailed gas/gas-liquid dynamics whereupon DME synthesis/aqueous-phase glycerol reforming kinetics, thermodynamics, thermal effects and variable gas flow rate due to chemical/physical contractions were accounted for. The integrated process is intended to minimize abundant glycerol by-product streams via an energy efficient alternative for producing DME. It presents an opportunity to improve the economics of green DME synthesis by cost reduction of biosyngas production while improving thermal efficiency of DME synthesis. (C) 2012 Elsevier E.V. All rights reserved.