Design aspects of membrane reactors for dry reforming of methane for the production of hydrogen

This paper presents an evaluation of various plant designs incorporating high-temperature membranes for the dry-reforming reaction of methane for hydrogen production. Two different types of membranes are evaluated: a high-temperature ceramic membrane to be used in the catalytic reformer and a carbon-based molecular sieve membrane to be used in the plant's purification section. Membranes evaluated in this work either are commercially available or have been demonstrated at the laboratory scale. Only operating energy costs for the various designs are presented, because at this stage of their development, commercial membranes are still prohibitively expensive and the cost of the laboratory membranes is unknown. Comparison of the energy costs of the various designs suggests, however, where future development work may be warranted. Among the plant designs considered, those utilizing the carbon-based membranes had the lowest energy requirements. Designs using commercially available high-temperature ceramic membranes exhibiting Knudsen diffusion separation factors were generally found to be inefficient. A unique design utilizing a yet-to-be-developed microporous ceramic membrane is also presented. A plant utilizing this membrane is shown to be more energy efficient and simpler to operate than conventional hydrogen plants.