Patent landscape for biological hydrogen production.

Research and development of biological hydrogen production have expanded significantly in the past decade. Production of renewable hydrogen from agricultural, forestry, or other organic waste streams offers the possibility to contribute to hydrogen production capacity with no net, or at least with lower, greenhouse gas emissions. Significant improvements in the volumetric or molar yields of hydrogen production have been accomplished through genetic engineering of hydrogen synthesizing microorganisms. Although no commercial scale renewable biohydrogen production facilities are currently in operation, a few pilot scale systems have been demonstrated successfully, and while industrial scale production of biohydrogen still faces a number of technical and economic barriers, understanding the patent landscape is an important step in developing a viable commercialization strategy. In this paper, we review patents filed on biological hydrogen production. Patents on biohydrogen production from both the Canadian and American Patents databases were classified into three main groups: (1) patents for biological hydrogen by direct photolysis; (2) patents for biological hydrogen by dark fermentation; and (3) patents for process engineering for biological hydrogen production.