Use of glycerol in substitution of sugarcane vinasse in off-season period to maintain the methane production in anaerobic reactor

Abstract

Wastewater treatment systems that use anaerobic processes are promising for the removal of organic pollutant load from vinasse, associated with the biogas production, which has aroused interest in several sectors of society. The scientific interest points to improvement of the degradation process of this effluent, by interpretation of the associated metabolic pathways, allowing the implementation and maintenance of processes involved with high efficiency. Common to the area scientists and technicians is the interest in production of biomethane for bioenergy generation. The interruption in the operation of anaerobic reactors in off-season periods is surely a great challenge to be faced in anaerobic wastewater treatment from sugar and alcohol industries, since the restarting period is slower than desired. Another residue with high organic content that deserves attention is glycerol, a product of biodiesel production. The hypothesis presented in this research is that the processing by anaerobic digestion of glycerol can generate biogas and maintain active microbial population in reactors treating vinasse, during the off-season period. In this context, an anaerobic structured bed reactor (ASTBR) will be used for the development of this research to study the exchange of feed with vinasse and glycerol. The experimental study will be conducted in five continuous phases, in which substitution of substrates will occur in organic load proportions of 100% vinasse; 50% vinasse and 50% glycerol; 100% glycerol; 50% vinasse and 50% glycerol; and 100% vinasse, respectively, maintaining organic loading rate of 5 kg m-3 d-1. Thus, the use of anaerobic codigestion from biofuel production residues will be evaluated in order to provide improvements to the monodigestion process, enhancing energy recover in biogas. (AU)