Membrane reactor based hydrogen separation from biomass gas - A review of technical advancements and prospects

The world is bound to make a gradual shift from a hydrocarbon economy towards a hydrogen economy. This shift is being facilitated by the technological development in hydrogen energy that is occurring around the world. Gasification of biomass for generating biomass synthesis gas is a promising source for the distributed power generation concept as it is based on the local raw material supply. This concept has to be augmented by hydrogen fuel cell technology for modular, efficient and environmentally benign implementation. This provides the platform for looking at the option of separating hydrogen from biomass synthesis gas which is composed of H-2, N-2, CO, CO2, CH4, Tar, alkali traces and particulate matter at varying compositions depending on the biomass and operating conditions. This paper makes a critical review of the attempts made to reform and separate hydrogen through a hydrogen permeable membrane reformer reactor as it provides the energy efficient route. The feasibility and various membranes from palladium to ceramic membranes used in the reactor configurations and the engineering problems of the reactor will be analyzed. The inherent problems in providing a one shot modular solution for solving the problem will be discussed in the paper.