Renewable Energy, Vol.128, 484-494, 2018
Recovery of ethanol from scrubber-water by district heat-driven membrane distillation: Industrial-scale technoeconomic study
Membrane distillation (MD) integrated with a district heating network (DHN) to supply the heat demand has been investigated in a bioethanol production plant (BP). The specific application considered here is ethanol recovery from fermentation off-gas (CO2) scrubber water, where the main objective of this study was to develop an air gap MD system that is driven by heat from DHN, thereby offloading the steam driven distillation column. Experiments conducted on an MD laboratory facility combined with data from the bioethanol industry were used to assess the technological and economic feasibility of this integrated MD-DHN-BP system. Comparisons were also made between the distillation column and MD units regarding heat demand and economic savings. Results of the study showed that MD could be a competitive technology for ethanol recovery given that low-grade heat such as from district heating network or waste heat is accessible. (C) 2017 Elsevier Ltd. All rights reserved.
Keywords:Membrane distillation;District heating;Bioethanol;Energy demand;Technoeconomy;CO2 scrubber;Exergy;Thermal efficiency