Effect of flow configuration on the behaviour of a membrane reactor operating without sweep gas

M.E. ADROVER; A. ANZOLA; S. SCHBIB; M. PEDERNERA; D. BORIO

CATALYSIS TODAY

ELSEVIER SCIENCE BV

Año: 2010 vol. 156 p. 223 - 228

0920-5861

A  simulation  study  of  a multitubular membrane  reactor  for  the water  gas  shift  reaction  is  presented. No sweep gas is considered. Two alternative flow configurations between the retentate and permeate streams are compared: cocurrent and countercurrent. The influence of the flow scheme on the ignition temperatures, CO conversions and axial temperature profiles is analyzed. Simple algebraic equations are derived to predict the temperature rise along the eactor length. The cocurrent scheme enables the attenuation of the thermal effects  in  the membrane  reactor, by minimizing  the  temperature  rise  in  the catalyst bed. Conversely,  the temperature rise corresponding to the countercurrent scheme is considerably higher than that of the cocurrentconfiguration. Both  thermal  increases  exceed  the  temperature  rise  of  a  conventional  adiabatic  fixed-bed reactor. Under countercurrent flow, the membrane reactor could exhibit steady-state multiplicity because of the heat feedback introduced by the permeate stream.