Supercritical Carbon Dioxide Decaffeination Process: a Life Cycle Assessment Study

Abstract

This work aimed at evaluating the environmental performances of a coffee decaffeination process driven by carbon dioxide at supercritical conditions, using a Life Cycle Assessment approach (LCA). In the last years, the global decaf coffee market has reached about 10 %, with growing diffusion mainly in developed areas. This increasing trend is mainly due to the preservation of the coffee taste related to a clear improvement in terms of quality of the decaffeination processes. The caffeine extraction stage, core unit operation of the decaffeination process, may be performed in different ways. Among the different processes, the most selective one, for removing just caffeine and no other flavour precursors from coffee, is based on supercritical carbon dioxide (scCO2). The aim of this work is to carry out a LCA analysis to determine the environmental impacts of industrial stages (from gate to gate) of the caffeine extraction process with supercritical carbon dioxide, reporting all the results to the chosen functional unit (1 kg of decaffeinated coffee). The data were analysed using SimaPro 8.0.5 software in order to identify the environmental key performance indicators (KPIs). Primary data and the Ecoinvent database were used for the Life Cycle Inventory (LCI), according to the reference standard for LCA (i.e., ISO 14040-14044).