Synergetic conversion of microalgae and CO2 into value-added chemicals under hydrothermal conditions

A novel approach for the synergetic conversion of microalgae including its residue after biodiesel extraction and CO2 (or HCO3-) into chemicals is reported for the first time. Results show that CO2 (or HCO3-) can be selectively reduced into formate with microalgae as a reductant, and simultaneously HCO3- itself significantly enhances the selective conversion of microalgae into organic acids and N-substituted lactam. The mechanism study showed that the lactam from the protein in microalgae contributed to the conversion of HCO3- into formate. The present study provides a new and green method for efficient utilization of microalgae and CO2 conversion.