Techno-economic Analysis of Sequential Extraction for Coffee Waste Valorization: Supercritical Ethanolic-CO2 Followed by Enzymatic Treatment

Defective green coffee beans represent a waste product derived from coffee manufacturing, amounting to approximately 1,900 tons annually at the studied location. The valorization of defective green coffee beans into value-added products simultaneously reduces waste and augments the revenue of coffee bean producers. This investigation employed enzymatic treatment to synthesize bioactive peptides from defective green coffee beans. In previous work, the defatting method was questioned regarding its economic viability, particularly supercritical ethanolic carbon dioxide extraction. Hence, the final products were produced using three distinct defatting methods: SCE. 1, supercritical ethanolic carbon dioxide as a base case; SCE. 2, supercritical carbon dioxide without ethanol as a co-solvent; and SCE. 3, ethanolic maceration. Techno-economic analysis serves as a decision-making tool for engineers to assess the feasibility of innovative technologies. Sensitivity analysis revealed that the peptide selling price is a critical factor influencing project success. These results suggest that producing peptides from defective coffee beans by SCE. 2 is both technically feasible and economically viable for two reasons. Firstly, reducing ethanol consumption decreases operational expenses. Secondly, the oil extracted using pure supercritical carbon dioxide exhibits superior quality compared to that obtained through ethanolic extraction.