On the conceptual modeling, economic analysis and life cycle assessment of partial dealcoholization alternatives of bitter extracts

Abstract

In this paper, we will analyze the economic and environmental performance of three different technologies for the on-site concentration of a bitter extract of herbs with simultaneous reduction of its alcoholic content to be able to obtain a beverage without alcohol off-site through the addition of deionized water. A base case, in which the bitter extract from the herbs extraction process is transported to the blending-bottling plant without any treatment is also considered.In all cases, the conceptual design of each alternative will resort to models built from experiments at lab scale.For the case of nanofiltration with the membrane NF99 HF (Alfa Laval, Sweden), a model allowing the estimation of the overall permeation coefficient and the variation of the osmotic pressure difference throughout the process was developed. For the scaling-up of this variant, the pressure loss issue was taken into account.Pervaporation with membranes PERVAP 4060 (Sulzer Chemtech, Switzerland) and Pervatech PDMS (Pervatech BV, The Netherlands) was also studied including a scaling-up incorporating the heat integration between the retentate stream entering the membrane module and the permeate stream condensed via a vapor compression refrigeration system.Finally, simple distillation was also investigated due to a favorable separation factor of ethanol at moderate operating pressures, availability of this technology and ease of operation.A remarkable outcome of our research is that for each technology we were able to find operating windows where both economic and environmental benefits can be achieved with respect to the base case. Whereas the environmental performance of each technology was evaluated resorting to life cycle analysis, its economic feasibility was assessed through economic indicators such as the payback period and the internal rate of return IRR.The best economic and environmental scores were reached by the nanofiltration variant operated at intermediate pressures. The payback period for this alternative was just 3 years with an IRR of 31% considering a lifetime of 10 years. The environmental benefits of adopting to this technology were clearly reflected in the results of the life cycle assessment.