| Author | Sarker, Nilay Kumar |
| Call Number | AIT Thesis no.ET-18-05 |
| Subject(s) | Microalgae
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Energy |
| Publisher | Asian Institute of Technology |
| Abstract | In this study both theoretical work (mathematical model and simulation) and laboratory experiment was conducted on microalgae. Most of the focus was on Chlorella vulgaris and rest of the work was done on Chlorella ellipsoidea. A mathematical model on growth rate was derived which included effect of light intensity, temperature, concentration of carbon, nitrogen and phosphorus. Effect of changing the parameters and also sensitivity analysis was performed on C. vulgaris. N and P was found as most sensitive elements. Then simulation was performed on open pond and PBR to find out algal growth and bioremediation and based on the overall result, PBR was found better performer. In PBR with freshwater, algal productivity was 5.4 times and with wastewater algal productivity was found up to 35 times higher than open pond. Maximum N and P removal efficiency of wastewater was 90%in PBR and 70% in open pond. Then experiment was conducted on C. vulgaris to find out better option between indoor and outdoor photobioreactors (PBRs). For outdoor cultivation, productivity in PBR3 was 0.096 g/l/d and in PBR4 productivity was 0.062 g/l/d. In indoor cultivation, PBR2 did not show any growth and productivity in PBR1 was 0.0131 g/l/d. Total operating cost of PBR1, PBR3 and PBR4 was 336, 57 and 26 thb, capital cost of PBR1, PBR3 and PBR4 was 21075, 370 and 370 thb. Algal productivity, lab scale energy consumption, operation cost and capital cost were considered and based on all these considerations outdoor PBR was chosen. Then more experiment was conducted on C. vulgaris and C. ellipsoidea to find out better design considerations. Better productivity was found with use of filtered wastewater, pH control, limited CO2 supply, light intensity control with a roof. pH should be maintained from 7.0 to 8.0, commercial CO2 (99.8%) should be supplied at a rate of maximum 1.25 liter/min and maximum for 5 minutes, but pH should never go below of 5.0 due to CO2. Sunlight intensity should be maintained below 30000 lux with a roof or shed. Aeration should be provided continuously during the whole time period of cultivation. Growth rate of C. ellipsoidea was better than C. vulgaris when both were cultivated without any control. |
| Year | 2018 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Energy Technology (ET) |
| Chairperson(s) | Salam, Abdul P.; |
| Examination Committee(s) | Kumar, Sivanappan;Singh, Jai Govind; |
| Scholarship Donor(s) | Asian Institute of Technology Fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2018 |