Constructing and Testing a Photobioreactor Designed for Precise Characterizations of Growth of Microalgae for Biofuel Applications
AIChE Annual Meeting
Monday, November 14, 2016 - 10:00am to 12:30pm
Initial experiments were conducted to test the Alginator using Chlorella vulgaris in WFAMC media where growth of 6.7 mg/L was more than 10-times greater than achieved in a control shake flask culture (0.342 mg/L) due to extended exponential growth beyond an optical density of OD-550nm = 10. Towards evaluating energy and carbon capture efficiencies, Chlorella was grown on replete and â?? nitrogen-limited WFAMC media. Biomass was characterized by dry weight, hydrothermal liquefaction (HTL), bomb calorimetry, and optical density. As expected, N-limited growth was reduced considerably to 4.71mg/mL. This result clearly indicates that the Alginator provides for rapid growth of algae to high cell densities as a result of its design which will be the basis of comparing numerous other algae for energy capture efficiency. Using HTL, the crude oil yield from the Alginator was 24 ± 1.5% in complete media and 18.3 ± 4% in nitrogen limited media. The lower yield in this preliminary test was unexpected, as we hypothesized that higher fatty acid content during nitrogen limitation would improve HTL yield. Further work is needed including our recent reconstruction of multiple Alginators where we will be able to better control temperature and more rapidly test different algae and growth conditions. A major goal of this work will be to provide a well-defined energy balance to assess energy and CO2 capture efficiencies.