Effect of different nitrogen ratio on the performance of CO absorption and microalgae conversion (CAMC) hybrid system.

CO absorption hybrid with microalgae conversion (CAMC) could be a promising alternative for the conventional CO capture technologies. The hybrid process could avoid the challenges of thermal energy consumption in the conventional desorption process and nutrition consumption in the typical algae cultivation process. In this work, the influence of different nitrogen ratio (NHHCO:NaNO) on the performance of the proposed hybrid CAMC process was investigated. Experimental results indicated that adding NHHCO into cultivation solution could promote Spirulina platensis growth. When the ratio of NHHCO and NaNO was set at 1:4, carbon utilization efficiency of the hybrid process could achieve 40.45%, which was higher than the conventional microalgae CO fixation processes (around 10%-30%). In addition, carbon sequestration capacity increased to 178.46 mg/L/d. It could be observed that CO absorption-microalgae conversion (CAMC) hybrid system has the potential for cost-effective CO capture and utilization.