Techno-Economic Analysis of Vinasse Treatment Alternatives Through Process Simulation: A Case Study of Cuban Distillery

Abstract

Purpose Vinasse is one of the organic industrial effluents with major polluting effect. The objective of this work was to perform a techno-economic assessment of vinasses treatment alternatives for valorization of this waste through process simulation with Aspen Hysys v10.0. Methods Four alternatives were studied: (A_1) incineration and electricity generation, (A_2) desalinization, (A_3) anaerobic digestion and electricity generation and (A_4) drying. The selected packages for the evaluation and prediction of properties were: Lee-Kesler-Plöcker and NBS Steam, NRTL-Ideal, Peng-Robinson-Stryjer-Vera and NBS Steam and NRTL-Ideal respectively; the validation in these cases was carried out with data reported in the literature. The economic evaluation was carried according to the changes that each alternative determines in each one of the elements of effective cash flow comparing with the actual condition. Results With the alternative A_1, fertilizers ashes are obtained removing all the residual and the energy generation. By the alternative A_2, fertilizers salts and desalinate vinasses (for animal food) were obtained. By the alternative A_3, energy is generated from biogas. By the alternative A_4, dry vinasse is obtained which is used as fertilizer and animal food. Conclusion The polluting effect of the vinasse can be reduced with the proposed treatment alternatives. It was showed that the alternatives are feasible, being the alternative A_1 the best, with a NPV of $ 1.29 MMUSD, IRR 25.5% and DPBP 2.7 years. Process simulation are a valuable supporting tool when making decisions in investment projects for valorization of vinasse from the ethanol industry.