Critical challenges in biohydrogen production processes from the organic feedstocks

The ever-increasing world energy demand drives the need for new and sustainable renewable fuel to mitigate problems associated with greenhouse gas emissions such as climate change. This helps in the development toward decarbonisation. Thus, in recent years, hydrogen has been seen as a promising candidate in global renewable energy agendas, where the production of biohydrogen gains more attention compared with fossil-based hydrogen. In this review, biohydrogen production using organic waste materials through fermentation, biophotolysis, microbial electrolysis cell and gasification are discussed and analysed from a technological perspective. The main focus herein is to summarise and criticise through bibliometric analysis and put forward the guidelines for the potential future routes of biohydrogen production from biomass and especially organic waste materials. This research review claims that substantial efforts currently and, in the future, should focus on biohydrogen production from integrated technology of processes of (i) dark and photofermentation, (ii) microbial electrolysis cell (MEC) and (iii) gasification of combined different biowastes. Furthermore, bibliometric mapping shows that hydrogen production from biomethanol and the modelling process are growing areas in the biohydrogen research that lead to zero-carbon energy soon

Biological processes for hydrogen production

Methane is produced usually from organic waste in a straightforward anaerobic digestion process. However, hydrogen production is technically more challenging as more stages are needed to convert all biomass to hydrogen because of thermodynamic constraints. Nevertheless, the benefit of hydrogen is that it can be produced, both biologically and thermochemically, in more than one way from either organic compounds or water. Research in biological hydrogen production is booming, as reflected by the myriad of recently published reviews on the topic. This overview is written from the perspective of how to transfer as much energy as possible from the feedstock into the gaseous products hydrogen, and to a lesser extent, methane. The status and remaining challenges of all the biological processes are concisely discussed