Techno-economic analysis of a food waste valorization process via microalgae cultivation and co-production of plasticizer, lactic acid and animal feed from algal biomass and food waste.

A techno-economic study of food waste valorization via fungal hydrolysis, microalgae cultivation and production of plasticizer, lactic acid and animal feed was simulated and evaluated by Super-Pro Designer®. A pilot-scale plant was designed with a capacity of 1 metric ton day(-1) of food waste with 20 years lifetime. Two scenarios were proposed with different products: Scenario (I) plasticizer & lactic acid, Scenario (II) plasticizer & animal feed. It was found that only Scenario I was economically feasible. The annual net profits, net present value, payback period and internal rate of return were US$ 422,699, US$ 3,028,000, 7.56 years and 18.98%, respectively. Scenario II was not economic viable due to a deficit of US$ 42,632 per year. Sensitivity analysis showed that the price of lactic acid was the largest determinant of the profitability in Scenario I, while the impact of the variables was very close in Scenario II.