Thesis (M.Eng.)--Chulalongkorn University, 2013

The cultivations of both Ankistrodesmus sp. and Scenedesmus sp. were carried out in a large scale non-baffled flat plate airlift photobioreactor (NB-FP-ARPBR). This placed a focus on the design effect of the reactor using the reactors of different widths, i.e. 20, 30, 40 and 50 cm and different unaerated liquid heights i.e. 40, 50 and 60 cm, operated under Thailand climate conditions. As a whole, the configuration of the NB-FP-ARPBR had an influence on fluid flow behavior, light availability, temperature and other factors affecting the livelihood of microalgae. The size of reactor appeared to be statistically important for the growth in NB-FP-ARPBR for both Ankistrodesmus sp. and Scenedesmus sp. that grew best in NB-FP-ALPBR with the width of 50, followed by those with 40, 30 and 20 cm, respectively. However, Scenedesmus sp. was on exception at the unaerated liquid height of 40 cm where the growth rate was ordered from high to low as 50, 20, 40 and 30 cm, respectively. In terms of liquid height, both microalgae grew best in NB-FP-ALPBR with the height of 50, followed by those with 40 and 60 cm, respectively. There was no direct relationship between biochemical compositions with the configuration of NB-FP-ALPBR. Protein seemed to be the major composition (35-45%) whereas lipid was the minor. Carbohydrate was found to be rich when there was adequate light for the growth. The total investment cost was approx. 420.40 US$ per year where the major costs for the cultivation of Ankistrodesmus sp. and Scenedesmus sp. was the capital cost which contributed almost 43% of the total investment cost, followed by those with electricity (32%), nutrient (23%) and water (2%).