Energy and Exergy Cost Analysis of Two Different Routes for Vinasse Treatment with Energy Recovery

EasyChair Preprint 4076

Abstract

The vinasse, produced as the bottom product of the distillation column of the ethanol production process, is the main liquid residue of this industry. It is a dark brown liquid of acidic nature and high organic matter content, thus making it a polluting effluent. Currently, it is used to fertilise and irrigate sugarcane fields, taking advantage of its nutrients and high water content. However, its disposition is still a problem because of its high production rate, which ranges from 10 to 15 litres of vinasse per litre of ethanol produced. This way, this work addresses the vinasse problem by a preliminary exergy cost analysis of three alternatives for vinasse disposition with energy recovery and a Base Case for comparison purposes; being the analysed cases: i) a Base Case (conventional production process), ii) the vinasse concentration with subsequent incineration, iii) the vinasse biodigestion with burning of the produced biogas in the boiler of the cogeneration system, and iv) the vinasse biodigestion and subsequent biogas purification aiming at the biomethane production. The preliminary results show the clean biogas of Case iii as the product with the highest unit exergy cost (7.03), followed by the biomethane of Case iv (with a unit exergy cost of 6.95), indicating that important irreversibilities are associated to the biogas production route.

Keyphrases: Biodigestion, Exergy cost, Incineration, concentration, vinasse

@booklet{EasyChair:4076,
  author    = {Milagros Cecilia Palacios-Bereche and Reynaldo Palacios-Bereche and Silvia Azucena Nebra},
  title     = {Energy and Exergy Cost Analysis of Two Different Routes for Vinasse Treatment with Energy Recovery},
  howpublished = {EasyChair Preprint 4076},
  year      = {EasyChair, 2020}}