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Technoeconomic analysis of biofuel production from spent coffee grounds using supercritical ethyl acetate
Author(s)
Date Issued
March 1, 2026
Type
Article
Abstract
This study is a techno-economic analysis of biodiesel production from spent coffee grounds (SCGs) using ethyl acetate as an extracting solvent and a reactant through interesterification under supercritical conditions—a process called SCEA. Aspen Plus V12 was employed to simulate the SCEA process compared to the conventional biodiesel production process. Both processes operated at an original feed rate of 24,225 tonnes per year, but the production capacities of the conventional and SCEA processes were 1000 tonnes per year and 1800 tonnes per year, respectively. Because of the simplicity of SCEA, the fixed capital investment costs were lower than those of the conventional process. However, at the original feed rate, neither process was profitable within a project lifetime of 20 years. The production capacity of SCEA was increased to 4 times, 8 times, and 16 times its original size to identify the most effective scale for the production facility. The SCEA process commenced successfully with a production capacity of 7500 tonnes per year, but the payback period of 19.5 years was deemed unsatisfactory. The production capacities of 15,000 tonnes per year and 30,000 tonnes per year provided the payback periods of 7.67 years and 6.08 years, respectively. Nonetheless, the 15,000-ton plant requires 193,798 tonnes SCGs per year as feedstock, which is 12 times the annual coffee production in Thailand. Hence, this project is well-suited for large coffee producers when utilizing SCGs as a singular feedstock. Combining other feedstocks, such as microalgae, non-edible seeds, and waste fruit seeds, with SCGs presents an optional pathway for future research on biodiesel production.
Citation
Journal of Supercritical Fluids, 229, 2026