Development of a Dynamic Model of a Palladium Membrane Reactor for Water Gas Shift

A dynamic model of a palladium membrane reactor for the Water Gas Shift (WGS) reaction has been developed by using the ISAAC Dynamic© platform. The mono-dimensional, time depending model has been developed by coupling the simple models of WGS reaction and Pd-membrane, e.g. considering that separation and reaction occur simultaneously in a single cell. The model of the composite Pd-membrane includes the presence of defects in the palladium film and a multilayered support, while in the WGS model kinetics of the reaction is considered. Membrane model has been first validated by comparison with permeation measurements, in the 300-445°C temperature range, of two Pd-membranes 12 and 29 μm thick, respectively, obtained by electroless plating on a macroporous stainless steel support. The whole model has been then validated by using results of WGS tests performed at RSE at 410°C in a tubular palladium membrane reactor fed with a syngas mixture with a 7.6% CO concentration and H2O/CO ratio in the 2.7-3.6 range. Model results fit quite well experimental data; the model, however, slightly overestimates CO conversion at high H2 recovery (up to the 10%), mainly due to the fact that concentration polarization effects are not considered.