Techno-economic Assessment of Bioactive Compound Recovery from Potato Peels with Sequential Hydrothermal Extraction

Abstract The economic performance of Sequential Hydrothermal Extraction (SeqHTE) and subcritical water extraction (SWE) was evaluated in this study for recovering bioactive compounds from potato peels. The analysis included the cost estimation of additional units required for extract purification, such as polysaccharide separation, glycoalkaloid isolation, and two final product purification alternatives: filtration or adsorption. An annual plant capacity of 4,540 tonne of dry peel and an on-stream factor of 300 days were considered as a basis for the study. The tecno-economic analysis showed that overall the capital investments and the costs of manufacture for SeqHTE were from 1.5 to 2 times greater than for SWE. However, the economic performance of the two-stage system compared favorably with the one-stage approach in terms of. unit production costs. For SeqHTE with filtration and adsorption, the lowest price of the polyphenol product was estimated to be $0.43/kg and $67.00/kg, respectively. In contrast, for SWE these costs were $0.74/kg and $70.00/kg, respectively. The results of the study also showed that although purification with adsorption was notably more costly (5 to 7 times higher), it provided a significantly more refined and presumably a superior quality final product. Moreover, the sensitivity analysis showed that operating costs, bioactive recovery and the potential to generate co-products were the most important factors that affect economic performance. Therefore, because SeqHTE allows a more complete utilization of the biomass and the recovery of possibly more valuable bioactives; the two-stage process may provide an economical alternative and for valorizing potato peels.