Hydrogen: Current advances and patented technologies of its renewable production

摘要

Hydrogen is considered the energy of the future. In order to meet the requirements of a green production, many technological advances were achieved in the last 20 years. Reviewing these advances allows the understanding the constraints of the sector and the identification of the paths for future research. In this work three routes for renewable hydrogen production from renewable sources were reviewed with focus on patented technologies: dissociation of the H2O molecule, microbial production and thermochemical processes. Three patent databases were accessed, covering documents written in English, Spanish and Portuguese. Water dissociation is the only commercial technology and most efforts were identified in new materials for electrodes, new catalysts and reagent recycling. Microbial production is thermodynamic limited but strategies to maximize the production and overcome economic barriers are mostly related to the use of wastewaters, improving microbial communities' composition and genetic manipulation. Most patents of thermochemical production patents brought contributions to the efficient use of energy especially by the combination with other energy producing technologies. The establishment of a green hydrogen society is strongly dependent of future developments on new materials, recycle of chemical catalysts and efficient use of energy in the short-term. (C) 2020 Elsevier Ltd. All rights reserved.