Eventos Anais de eventos
ENCIT 2018
Brazilian Congress of Thermal Sciences and Engineering
COMPARISON BETWEEN TWO ALTERNATIVES FOR THE ENERGY USE OF VINASSE: CONCENTRATION-INCINERATION VS BIODIGESTION
Submission Author:
Milagros Cecilia Palacios-Bereche , SP
Co-Authors:
Milagros Cecilia Palacios-Bereche, Ana Carolina Medina Jimenez, Reynaldo Palacios, Silvia Azucena Nebra de Perez
Presenter: Milagros Cecilia Palacios-Bereche
doi://10.26678/ABCM.ENCIT2018.CIT18-0237
Abstract
The vinasse, effluent generated in the distillation step of the ethanol production process, has polluting characteristics and is generated in large amounts, making its disposition problematic and costly. This work addresses the vinasse problem in the ethanol production from sugarcane, through a comparison between two alternatives to treat it with energy recovery: i) concentration in a multiple-effect evaporator system and subsequent incineration, and ii) biodigestion. The comparison is carried out through mass and energy balances for the proposed routes evaluating two configurations of the cogeneration system; Configuration 1, using back-pressure steam turbines (BPST); and Configuration 2, using condensing-extraction steam turbines (CEST). Results indicated that for cases using CEST (where the electricity surplus is maximised), the electricity surplus resulted in the same range: 86.82 kWh/t of cane for the concentration-incineration route, and 84.81 kWh/t cane for the biodigestion route. Regarding cases with BPST, the concentration-incineration case presented a potential of 70.24 kWh/t cane of electricity surplus, which is 33.4% higher than the electricity surplus in the biodigestion case, because of the additional steam consumption in the vinasse concentration process; however, the bagasse surplus, in this case, resulted in 27.37 kg/t cane, which is 48.4% lower in comparison to the biodigestion case. Regarding the economic assessment, the concentration with incineration of vinasse presented better results of total annualised costs for CEST; while the biodigestion route was a better option for BPST.
Keywords
Biodigestion, vinasse biodigestion, Incineration, Vinasse
