The role of oxygen regulation and algal growth parameters in hydrogen production via biophotolysis

Genetic engineering for biohydrogen production from microalgae

“…Particularly popular strategies are the use of stable gene expression and genetic evolution. 76 Hydrogen production pathways from direct photolysis, indirect photolysis, and photo-fermentation are described in Figure 1 .

Figure 1 Overview of hydrogen production by microalgal chloroplasts (A) Direct photolysis process of microalgae.

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Assessing the waste heat recovery potential of liquid organic hydrogen carrier chains

“…Hydrogen is a promising energy carrier that can be produced from renewable energy sources, fossil fuels, or nuclear energy [8][9][10][11][12][13][14][15][16][17][18][19][20]. Fuel cells or combustion engines can use hydrogen to generate power without emissions [21].…”

Photo fermentative biohydrogen production potential using microalgae–activated sludge co-digestion in a sequential flow batch reactor (SFBR)

“…5 Efforts to utilize lignocellulosic feedstocks and photosynthetic microorganisms for biological conversion to bioH 2 have focused primarily on anaerobic digestion (AD) and secondarily on biophotolysis. 6,7 The AD of three microalgae genera, Chlorella, Chlamydomonas, and Scenedesmus sp., has been extensively researched due to their immense potential for producing bioH 2 and biogas. [8][9][10] Moreover, it has been reported that AD is a viable strategy for producing bioenergy from microalgae.…”

“… 11 However, there are several constraints such as environmental factors, microalgal species, input/output energy waste, oxygen (O 2 ) regulation, nutrient level, external substrates, light intensity, and pH which might hamper the performance efficiency of microalgae. 6 The co-culturing of microalgae and bacteria, in this case, is a promising technique to regulate O 2 which is one of the constraints during microalgal bioH 2 production. 12 However, using waste resources such as activated sludge as a source of bacteria has also shown a significant enhancement in bioH 2 .…”