Microalgal biohydrogen production considering light energy and mixing time as the two key features for scale-up

Biohydrogen production from model microalgae Chlamydomonas reinhardtii : A simulation of environmental conditions for outdoor experiments

“…Mixing time was determined according to the pH pulse technique under non-aerated conditions using HCl and NaOH as tracer solutions [23]. The magnetic mixing was done with Gerhardt MG-H systems using magnetic stirrers.…”

“…In aerobic culture phase under the same light conditions transfer time was relatively shorter (22 ± 2 h) to reach transfer chlorophyll amount when compared to control (mixing time of 2 min). With 1 min mixing time the mass transfer was more efficient, and the exposure of cell to light was more homogeneous allowing a better utilization of light [8,23]. With increased mass transfer characteristics, accessibility of cells to nutrients and gases in culture medium was improved.…”

“…There are several bottlenecks related to microalgal metabolism that need to be overcome before hydrogen production can be scaled up to an industrial level, and the optimization of the environmental conditions is also another issue to be addressed [4,8,9,22,23]. Besides highlights on outdoor productions are key points for microalgal biohydrogen production aiming to have a share in global hydrogen energy market [24].…”

From the Ancient Tribes to Modern Societies, Microalgae Evolution from a Simple Food to an Alternative Fuel Source

“…(2) the relation of inhibitors with hydrogen production mechanism; (3) microalgae speciesspecific hydrogen production and screening of certain strains as hydrogen-producing machineries; (4) genetic basis of hydrogen production both in terms of enzymes and mechanistic models; (5) regulation of cell metabolism to shift their storage metabolism; (6) the effect of nutrition to PSII system; (7) evaluation of biophotolysis; (8) genetic engineering tools for an efficient production; (9) commercialization and scale-up; (10) immobilization for sustainable biohydrogen production; and (11) evolutionary development of hydrogen-producing machinery, which were highlighted in a series of comprehensive reports (Ghirardi et al, 1997;Wykoff et al, 1998;Melis et al, 2000;Kosourov et al, 2002;Forestier et al, 2003;Posewitz et al, 2004;Ghirardi et al, 2005;Kruse et al, 2005;Meyer, 2007;Laurinavichene et al, 2008;Kosourov and Seibert, 2009;Matthew et al, 2009;Faraloni and Torzillo, 2010;Gaffron, 1939;Kruse and Hankamer, 2010;Oh et al, 2011;Srirangan et al, 2011;Meuser et al, 2012;Oncel and Sabankay, 2012;Scoma et al, 2012;Oncel, 2013;Torzillo and Seibert, 2013;Oncel and Kose, 2014).…”

“…Mixing time also has various effects on microalgal metabolism, light distribution into PBR, light/dark cycle frequency, and heat and mass transfer properties affecting bulk biomass production. Also, it is stated that mixing time has a significant effect on H 2 production, too (Oncel and Sabankay, 2012). Reduction in the mixing time is the key to a better transfer.…”