Evaluation of microalgae cultivation using recovered aqueous co-product from thermochemical liquefaction of algal biomass

This study characterized the ACP stream from the TCL of Spirulina and evaluated its potential as a nutrient source for cultivation of microalgae. TCL of 100 g of dry Spirulina resulted in 40% BioOil and 429.80% ACP. The ACP was found to have high nitrogen (16,200 mg L−1), phosphorus (795 mg L−1), potassium (11,260 mg L−1) and secondary and micronutrients. Growth media were prepared using ACP as sole nutrient source in deionized water at 0.2%, 0.33%, 1%, and 10% v/v concentration and compared with a standard growth medium (BG 11) for algal cultivation. Chlorella minutissima was grown in these media for 12 days and monitored for biomass concentration, total chlorophyll and lipids. Biomass productivities with the ACP added media at 0.2% and 0.1% concentration were 0.035 and 0.027 g L−1 d−1, respectively, compared to 0.07 g L−1 d−1 in BG 11.