Development of a Carbon Dioxide Generation and Delivery System for Carbon-Efficient Cultivation of Microalgae

Abstract

Microalgae hold immense promise to help the world meet burgeoning energy and food needs. A major operational cost when commercially growing microalgae is the supply, storage, and delivery of carbon dioxide. To advance algal culture technique and improve cost effectiveness, this study sought to reduce CO2 wastage without impeding algal growth. A carbon dioxide generation and delivery module (CGDM) was developed that delivers CO2 generated on demand from bicarbonate solution. The system was successfully used to cultivate the green microalgae Chlorella vulgaris and Dunaliella salina. Using the CGDM, C. vulgaris culture reached a higher biomass concentration after a week of growth while using a small fraction of the CO2 culture sparged with 0.4350% CO2-enriched air required. As liquid carbonates can be easily obtained from waste CO2, the approach described herein presents a sustainable solution to reduce production costs of algal culture while minimizing CO2 emission to the environment.