Resource recovery from sugarcane vinasse by anaerobic digestion-A review

The increase in biofuel production by 2030, driven by the targets set at the 21st United Nations Framework Convention on Climate Change (COP21), will promote an increase in ethanol production, and consequently more vinasse generation. Sugarcane vinasse, despite having a high polluting potential due to its high concentration of organic matter and nutrients, has the potential to produce value-added resources such as volatile fatty acids (VFA), biohydrogen (bioH2) and biomethane (bioCH4) from anaerobic digestion. The objective of this paper is to present a critical review on the vinasse treatment by anaerobic digestion focusing on the final products. Effects of operational parameters on production and recovery of these resources, such as pH, temperature, retention time and type of inoculum were addressed. Given the importance of treating sugarcane vinasse due to its complex composition and high volume generated in the ethanol production process, this is the first review that evaluates the production of VFAs, bioH2 and bioCH4 in the treatment of this organic residue. Also, the challenges of the simultaneous production of VFA, bioH2 and bioCH4 and resources recovery in the wastewater streams generated in flex-fuel plants, using sugarcane and corn as raw material in ethanol production, are presented. The installation of flex-fuel plants was briefly discussed, with the main impacts on the treatment process of these effluents either jointly or simultaneously, depending on the harvest season.

Automated summary

This paper critically reviews the treatment of vinasse by anaerobic digestion focusing on the production of volatile fatty acids, biohydrogen, and biomethane. It discusses the effects of operational parameters on the production and recovery of these resources and presents the challenges of simultaneous production and recovery in wastewater streams generated in flex-fuel plants using sugarcane and corn as raw material for ethanol production. The installation of flex-fuel plants and their impacts on the treatment process of effluents depending on the harvest season are briefly discussed.