Waste to Sustainable Biohydrogen Production Via Photo-Fermentation and Biophotolysis − A Systematic Review

Abstract

Considering the environmental challenges humanity faces in the 21st century, it is obvious that there is an enormous need for change of the global energy map. Under these circumstances, new energy sources and intermediates must be considered as options to limit the greenhouse gases emissions and mitigate climate crisis. Biohydrogen production is one of the most appealing options, due to hydrogen's multiple applications and zero emissions as a fuel, to empower a future hydrogen circular economy. In this review article we focus on two methods that are not widely used at industrial scale but have many future possibilities and growth margins: (a) photo-fermentation and (b) bio photolysis. Both methods are light dependent and need photobioreactors to function and produce significant amounts of biohydrogen. Based on an extensive literature search and systemic analysis of the findings, presentation of the different reactants, operating conditions and biohydrogen productions, key factors and effecting parameters were discussed. Temperature, pH, light intensity and photobioreactor operation and design are some of the most significant factors that define the biohydrogen production rates and yields. Innovative solutions and approaches are presented including biotechnological and genetic engineering modifications to microorganisms, as well as combinations of some hybrid biohydrogen producing methods, especially dark and photo fermentation. For implementing a biohydrogen circular-economy, different wastes were explored as potential feedstocks, and overcoming of major bottlenecks that biophotolysis and photo-fermentation face in the transition to a sustainable biohydrogen economy, were discussed.

Sustainable production of biofuels and bioderivatives from aquaculture and marine waste

“…Photo fermentation was coupled with dark fermentation to convert residue from anaerobic digestion from fish waste into biohydrogen (Melitos et al, 2021). Ghimire et al (2015c) reported that connecting the DF-Photo Fermentation reduces the control of operating parameters such as pH and the process impacts on the energy yield reaching 55 MJ/kg volatile solid food waste, adding a synergistic effect to the overall energy recovery during the conversion of food waste.…”

A Review on Mathematical Modeling of Different Biological Methods of Hydrogen Production

“…Biophotolysis for hydrogen production is the dissociation or splitting of the water molecule by hydrogenase enzyme under the action of light energy by microorganisms like cyanobacteria and microalgae [26,27].…”

“…The first phase is a light-dependent-phase aerobic process, where the microbes synthesize carbohydrates from water and carbondioxide using light energy (Equation (3)). In aerobic conditions with the supply of air, the biomass progressively increases and is concentrated until it reaches a state of stabilization [26,31].…”

Hydrogen Production Using Modern Photocatalysts

“…Pyrolysis and gasification of materials such as grass, straw, or biological waste are possible thermochemical routes. Alternatively, biophotolysis, based on the biological gas conversion and fermentation reactions, may also be applied [97][98][99]. In water electrolysis, on the other hand, an electric current is used to separate water into hydrogen and oxygen.…”

“…This production process achieves efficiencies of up to 70% [82]. In proton exchange membrane (PEM) electrolysis, the protonconducting membrane serves as the electrolyte, and the efficiency of this process is about 50% [99].…”