Process Design and Optimization Of Integrated Algal Biorefinery Considering the Environmental and Economic Aspects

The integrated algal biorefinery (IABR) was deliberated as a feasible alternative to fossil fuels. After the processes of algae cultivation and pretreatment, the algae biomass with different carbohydrate/lipid contents is split into the carbohydrate process for producing fuel/chemicals and the oil process for producing fuel/energy. Four frameworks of IABR are presented: (i) Scenario 1 (SC1) is designed to produce lactic acid/biodiesel, (ii) Scenario 2 (SC2) is an extension of SC1 by increasing the production of biooil, (iii) Scenario 3 (SC3) is an extension of SC2 by increasing the cogeneration of electricity/heat, and (iv) Scenario 4 (SC4) is an extension of SC3 by increasing the production of acetone, butanol, and ethanol (ABE). Through the process design and optimization algorithms, a few comparisons show that (i) the total eCO 2 emission of SC3 is lower than SC2 by 7.8% but it is higher than SC1 by 9.9%, (ii) the total profits of SC2 and SC3 are higher than SC1 by 40%, and (iii) the total eCO 2 emission of SC4 is lower than SC1 by 20.5% and the total profit of SC4 is larger than SC3 by 10.4%