Insights from combining techno-economic and life cycle assessment – a case study of polyphenol extraction from red wine pomace

To determine the environmental and economic performance of emerging processes for the valorization of red wine pomace, a techno-economic assessment (TEA) and a Life Cycle Assessment (LCA) are combined at an early design stage. A case study of two polyphenol extraction methods at laboratory scale, solvent extraction (SE) and pressurized liquid extraction (PLE), were first analyzed via a carbon footprint (CFP). Subsequently, the laboratory scale design was improved and translated into industrial scale and a TEA was performed on the industrial scale designs. Finally, LCA was applied again with all impact indicators and the information gathered from both the TEA and LCA was combined into concise decision support, using Multiple Criteria Decision Analysis (MCDA). SE performs better than PLE, due to a lower solvent to DW ratio and a less expensive processing setup in both environmental and economic terms. The CFP of at laboratory scale aided in showing potential environmental hotspots and highlighted the need to reduce solvent use. The MCDA showed a shift in decision support depending on how strongly economic or environmental benefits are valued and eases the interpretation of the 19 different indicators derived from the TEA-LCA results. Both SE and PLE with a solvent to dry weight (DW) ratio of 5 and 10, respectively, perform competitively while SE with a solvent to DW ratio of 10 outperforms PLE with a solvent to DW ratio of 25. The case study illustrated how early design calculations (CFP), and combined LCA and TEA may be combined to improve process design.