Production of renewable hydrogen by reformation of biofuels


  • The authors have declared no conflicts of interest in relation to this article.


Environmental concerns and sustainability issues dictate the production of energy carriers from renewable resources. Hydrogen is thought to be the most appropriate energy carrier in this respect, especially in combination with fuel cell technologies and distributed power generation schemes. Although renewable hydrogen can be produced from excess renewable electricity, this approach imposes difficulties related to storage, handling, and transportation. The use of biomass has been proposed for production of renewable hydrogen. The most effective way is to utilize biofuels as intermediates in the hydrogen and power production sequence. Appropriate biofuels are bioethanol, biogas, bio-oil, and glycerol. These molecules can be catalytically reformed, most efficiently with steam, at elevated temperatures, to yield hydrogen and carbon dioxide. For this purpose, appropriate catalysts have been developed, which exhibit high activity, selectivity toward hydrogen production and long-term stability. Stability of operation is very critical as deposition of coke on the catalyst surface is thermodynamically feasible and kinetically favorable in many cases and operating envelopes. Although noble metals are active and rather resistant to coke deposition, they are rare and expensive. Nickel and other transition metals have been investigated and significant research efforts have been extended to improve catalytic characteristics by appropriate choice of support material, metal dispersion, and additives in the metal or the carrier phases. Furthermore, elucidation of mechanistic aspects of the reformation reactions, other reactions which occur in sequence or in parallel as well as carbon deposition routes, is also utilized toward the development of appropriate catalytic materials and processes.