Simulation of the daily sunlight illumination pattern for bacterial photo-hydrogen production

Photofermentative Hydrogen Production in Outdoor Conditions

“…Solar light energy is warranted because it is a free resource that is abundant in nature. The earth receives about 5.7×10 24 J of solar light energy per annum [49]. Its usage for photofermentative hydrogen production not only saves on operating costs but also supports the concept of sustainable hydrogen production from renewable resources.…”

“…The cell growth of the PNSB was found to fit the logistic model [4,[58][59][60]. In outdoor operations, cell growth and hydrogen production were indicated to be dependent on the solar light intensity received [45,49,[51][52][53][54]61]. Temperature and the intensity of solar radiation vary daily, seasonally and geographically.…”

“…An East-West positioning of PBRs has been indicated to be the most suitable for receiving maximum sunlight energy and utilization [35,38,49,51,87]. PBRs facing East-West position were shown to receive higher amount of irradiance than South-North facing PBRs [87] and better utilization of long wavelength (red and infrared) that are prevalent in the mornings and evenings [72].…”

“…PBRs facing East-West position were shown to receive higher amount of irradiance than South-North facing PBRs [87] and better utilization of long wavelength (red and infrared) that are prevalent in the mornings and evenings [72]. Orientation of the PBRs with inclinations of about 90° or less were demonstrated to be more suitable for cell growth and hydrogen production [35,38,49] than their counterparts without inclination. With inclination of flat plate PBRs towards the sun, major sunlight was received on the inclined surface of the PBR and the backside surface of the PBR was illuminated by diffuse and reflected light that may be good for photosynthesis.…”

“…They observed that 69% of the incident light energy was absorbed in the first compartment (0-5 mm) and 21% was absorbed in the second compartment (5-10 mm). Similarly, cells in the deeper parts of the b i o r e a c t o r w e r e d e m o n s t r a t e d t o b e p o o r l y illuminated as much of the incident light energy was absorbed as 69%, 21%, 7%, 2% in the first, second, third and fourth compartments of a 20 mm bioreactor [49]. The reduction of a flat panel bioreactor depth from 4 cm to 2 cm led to an increase in the overall light Photofermentative Hydrogen Production in Outdoor Conditions 93 conversion efficiency from 0.13% to 0.53% [95].…”