Life cycle assessment of supercritical CO2 extraction of caffeine from coffee beans

The environmental impacts of caffeine extraction from coffee beans using supercritical carbon dioxide (scCO(2)) were evaluated, through a Life Cycle Assessment (LCA) approach. Using this process, two products of interest were obtained: caffeine and decaffeinated coffee. All the emissions to air, water and soil were reported to 1 kg of decaf coffee constituted by a 60/40 Arabica/Robusta blend. The performed analysis showed that agricultural stages, transportation and caffeine extraction are the steps mostly affecting the environmental categories under study. Therefore, the process was optimised, considering the fertilisers' amount reduction and the substitution of a portion of electricity at grid with electricity produced by photovoltaic panels. Using this improved scenario, a reduction of the environmental impact equal to 176% in terms of human health, 10.3% in terms of ecosystem diversity and 16.1% in terms of resource availability can be obtained.