New Proposal for Sugarcane Vinasse Treatment by Hydrothermal Carbonization: An Evaluation of Solid and Liquid Products

Abstract

Vinasse is a residue of ethanol production from sugarcane. In view of the problems associated with its disposal, this study aimed to propose a treatment for vinasse by hydrothermal carbonization. The influence of temperature (100 to 200 o C), acidity (1.7 to 8.3%) and reaction time (12 to 48 h) on the hydrothermal treatment was evaluated, as well the characteristics of the solid (hydrochar) and liquid (process water) products. For the solid product, two hydrothermal carbonization conditions stood out as leading to higher carbonization and yields. These conditions were 200 o C, 8.3% acidity and times of 12 and 48 h. For the process water, the carbonization reaction at 200 o C, 8.3% acidity and 48 h produced the highest discoloration and 77% reduction of total organic carbon. Thus, hydrothermal carbonization proved to be an efficient method to treat vinasse, and the hydrochar presents potential for use as fertilizers / soil conditioners, and also the process water after pre-treatment.

Fulvic acids from Amazonian anthropogenic soils: Insight into the molecular composition and copper binding properties using fluorescence techniques

“…TM is considered as a model of fertile soil, and researchers have been focusing on trying to reproduce this kind of soil in the laboratory, or at least, reproducing its characteristics (Cernansky, 2015). Techniques such as hydrothermal carbonization has been explored as an alternative to reproduce this anthropogenic soil particularities (dos Santos et al, 2020;Fregolente et al, 2020;Bisinoti et al, 2019;Bento et al, 2019;Santana et al, 2019;Melo et al, 2017;Silva et al, 2017;Kambo and Dutta, 2015). Therefore, it is essential to know the intrinsic characteristics of TM and this study can be a guide for those who seek to mimic these properties.…”

Insights on Molecular Characteristics of Hydrochars by 13C-NMR and Off-Line TMAH-GC/MS and Assessment of Their Potential Use as Plant Growth Promoters

“…The hydrothermal carbonization of agro-industrial wastes and residues stand out as an environmentally friendly process, since mild temperatures are generally applied, and the starting biomass can be dry or wet [ 34 ]. The use of sugarcane bagasse or vinasse, or the mixture of both, has been described as an efficient way to treat this industry by-products, obtaining hydrochar with high carbon, nutrient content and potential release of volatile compounds [ 35 , 36 , 37 ]. Hydrochars produced with phosphoric acid as additive showed a higher nutrient immobilization.…”

“…Hydrochars produced with phosphoric acid as additive showed a higher nutrient immobilization. On the other hand, the use of sulfuric acid in the reaction medium leaded to a hydrochar with a higher carbon content [ 35 , 36 ]. These characteristics would be interesting to hydrochar soil application, probably, being able to improve soil fertility or soil carbon storage, respectively.…”

Hydrochar from sugarcane industry by-products: assessment of its potential use as a soil conditioner by germination and growth of maize

“…Vinasse and sugarcane bagasse are the two main residues generated by ethanol production, and they are also considered by-products as they can be used for fertigation and energy co-generation, respectively [2]. However, an environment-friendly disposal for sugarcane industry by-products via hydrothermal carbonization has been proposed [3,4]. This process generates a solid product (hydrochar), whose composition suggests that it can be applied as soil conditioner [3][4][5].…”

“…However, an environment-friendly disposal for sugarcane industry by-products via hydrothermal carbonization has been proposed [3,4]. This process generates a solid product (hydrochar), whose composition suggests that it can be applied as soil conditioner [3][4][5]. The characteristics of hydrochar may vary depending on the composition of the reaction medium.…”