Design optimization of large-scale attached cultivation of Ettlia sp. to maximize biomass production based on simulation of solar irradiation

• Published in: Applied energy 2020-12, Vol.279, p.115802, Article 115802
• Main Authors: Kim, Sungwhan, Kim, Donghyun, Ryu, Byung-Gon, Chang, Yong Keun
• Format: Article
• Language: English
• Subjects: Attached cultivation; Design optimization; Ettila sp; Footprint biomass productivity; Green microalgae; Simulation of solar irradiation
• ISSN: 0306-2619; 1872-9118
• DOI: 10.1016/j.apenergy.2020.115802

[Display omitted] •Outdoor attached cultivation of Ettlia sp. in South Korea is estimated.•Tilt angle, facing direction, height, and distance were seasonally optimized.•Minimum distance made steeper tilt angle more favorable for biomass production.•Three optimum conditions were found based on economic circumstances.•Double-side MAP facing east/west had the highest footprint biomass productivity. In support of successful biomass production of green microalga Ettlia sp. through attached cultivation, estimation of footprint biomass productivity and optimization of the system was evaluated through comprehensive simulation of solar irradiation. Both temporal and spatial variation of solar irradiation and biomass productivity on the surface of the microalgae-attached panel (MAP) with every combination of design factors (tilt angle, facing direction, height, and distance of the MAP) were closely studied. While an increase in the height to the distance ratio (HDR) increased footprint biomass productivity, fixing the distances at their minimum made steeper tilt angle more favorable for footprint biomass productivity by having a smaller minimum distance. Footprint biomass productivity over the height revealed another important design index, a critical height, where footprint biomass productivity becomes maximum and saturated. Ultimately, three optimum conditions were identified based on economic circumstances: (1) double-side vertically standing MAP facing east/west, (2) 1 m high single-side MAP facing south with seasonal optimum angles, and (3) over 2.5 m high single-side MAP facing west with seasonal optimum angles. Corresponding estimated yearly average footprint biomass productivities were 22, 11, and 11.5 g/m2/day at the height of 3 m, 1 m, and 3 m, respectively.