Influence of Aqueous Phase of Hydrothermal Carbonization Feeding on Carbon Fixation by Microalgae

Abstract

CO2 biofixation is one of the most promising alternatives in CO2 capture and storage. In this study, the ability to cultivate microalgae and the influence of the use of the aqueous phase (AP) from hydrothermal carbonization (HTC) of coffee husk on the biofixation of CO2 were investigated. The influence of nutrient addition on the growth rate of Chlorella sp., was evaluated through the response surface methodology. The results indicate that the optimum nutrient levels were 0.20 g L−1 of sodium acetate and 1.32% (v/v) of AP. The effect of CO2 concentration on growth and biofixation kinetics were determined using 0.04, 5, 10, 15, and 30% (v/v) CO2. The maximum CO2 biofixation (71.00 mg L−1 d−1) and the highest biomass concentration (0.40 g L−1) were determined at 15% (v/v) CO2.