Enriching the conceptual modelling approach with environmental considerations: Application to the partial dealcoholization of wines

Abstract

In this work, and based on results from conceptual models, an environmental impact assessment was carried out using the ReCiPe midpoint and endpoint methodology for technologies in the partial dealcoholization of wines; namely, evaporative pertraction (EP), nanofiltration (NF), reverse osmosis (RO), pervaporation (PV), pervaporation with heat integration (PVHI) and spinning cone column (SCC). While the first three technologies are analyzed in their hybrid process version including a distillation stage, the PVHI variant considers the energy integration between the retentate and permeate streams through a vapor compression refrigeration system. In all cases, a decrease of ca. two percent points of alcohol in volume is considered. With the same input data the utility costs of each variant were also estimated. In this way, trade-offs between the economic and environmental performance of each alternative were addressed. In all cases, both a partially dealcoholized wine and an ethanol-rich effluent (50 % by volume or more) were obtained with the last sent to a distillery for material valorization. Regardless of the end point chosen, the PVHI variant showed the best environmental performance and thus was the most environmentally friendly alternative followed by variants SCC, PV, RO, NF and EP. On the other hand, from perspective based on utility costs results showed that the SCC variant requires the lowest costs, followed by the PVHI, PV, EP, RO and NF alternatives, respectively. From both economic and environmental point of view EP, NF and RO and were the worst alternatives given by the relatively high steam and cooling water consumptions required for these technologies to both achieve an alcohol-rich distillate with and a reduction in deionized water consumption of the corresponding partial dealcoholization step. In contrast, due to the high ethanol selectivity of the PDMS membrane used in experiments and the high ethanol recovery in conjunction with a high distillate composition achieved in the spinning cone column made alternatives PVHI and SCC as the better ones both in environmental and economic standpoints. It is precisely the possibility of heat integration of the pervaporation that accounts for the better environmental performance of the PVHI variant.