Detailed 2D CFD simulations assisted in determining the temperature profiles along the fixed bed reactors
showing that temperature differences of up to 105 ◦C may prevail in fixed bed membrane reactors without the use of a pre-reforming section.
this temperature difference can be limited to 10 ◦C adopting a pre-reforming section. Moreover, it was shown that the membrane area required for a fixed bed membrane reactor without pre-reforming could be up to 25% larger than that for a fluidized bed membrane reactor.
This effect is mainly due to the lower hydrogen permeation in the configurations that show a pronounced decrease in temperature and therefore low H2 concentrations at the reforming side of the membrane, penalizing its permeation performance. It can be concluded that a fixed bed reactor without any pre-reforming section would imply inefficient use
of the membrane surface, and performances close to fluidized bed reactor can be achieved with feed gas pre-reforming and reheating to the reactor temperature before the inlet.