Pd based membrane reactor for ultra pure hydrogen production through the dry reforming of methane. Experimental and modeling studies

A dense Pd-Ag membrane reactor (MR) with 100% hydrogen selectivity packed with either Rh/La2O3 or Rh/La2O3-SiO2 as catalysts was used to carry out the dry reforming of methane. The membrane reactor simulation was performed using a well-known reactor model. For this purpose, we employed the equations derived from complete kinetic studies of the dry reforming of methane reaction in connection with both catalysts. In addition, we developed the kinetic equation for the reverse water gas shift reaction (RWGS). The combination of detailed kinetic studies with the measured permeation flux for the Pd-Ag membrane allowed a complete comparison between experimental and simulated operation variables. The variables studied for both catalysts were methane conversion and hydrogen permeation as a function of the sweep gas flow rate. The correlation between methane conversion enhancement and hydrogen recovery confirmed that a good prediction was obtained with this model. The performance of two reactor configurations (membrane reactor and conventional fixed-bed reactor) and both co-current and counter-current flow modes were compared. The effect of various operating variables such as permeation area, sweep gas flow rate and feed composition upon conversion, product compositions and hydrogen recovery were analyzed. (C) 2011 Elsevier B.V. All rights reserved.