Autothermal reforming (ATR) of methane, which supplies the heat for endothermic steam reforming by internal combustion of methane, is an important process for synthetic gas production. The axial-distributed feeding of oxygen via a packed bed inert membrane reactor (MR) can reduce the peak temperature and improve the reactor performance. A modified MR, called mixed membrane reactor (MMR), combines permeable membrane tube wall and non-permeable tube wall provides extra degrees of freedom for reactor design and operation. For MR and MMR, this study presents the ternary-objective optimization analysis for maximizing hydrogen production rate, non-combustion selectivity and conversion of methane, using a 1D pseudo-homogeneous reactor model and the NSGA-II algorithm. Compared to MR, MMR can be operated under significantly higher oxygen permeation flux without violating the maximum temperature constraint. The non-combustion selectivity and conversion of methane of MR and MMR are close, however, the hydrogen production rate of MMR can be as high as 200% of MR.
Journal of Applied Science and Engineering 21(3), p.485-495