Fig. 1

Overview of feedstocks and productions of different biofuel generations. 1st generation biofuels utilize corn, soybeans, wheat, sunflower oil, and palm oil as feedstocks; 2nd generation biofuels utilize switchgrass, poplar, straw, and food waste as feedstocks; 3rd and 4th generation biofuels utilize microalgae as feedstocks, with microalgae being editable in 4th generation