Produção de Carboxilatos na fermentação anaeróbia a partir de resíduos orgânicos

Abstract

The bioproduction of carboxylic acids (CAs), by anaerobic digestion, from renewable resources, such as organic residues from agro-industrial activities, has attracted attention, because it contrib-utes to the reduction of environmental impacts and scarcity of raw materials, as well as high oil prices. This work aimed to research the use of organic waste available in Brazil through Anaerobic Digestion (AD) to generate basic chemical products for industry (platform chemicals), especially Carboxylates. The dissertation was developed in international cooperation between the IFG and the institutes in Germany, UFZ: the Center for Environmental Research, in German Helmholtz-Zentrum für Umweltforschung, abbreviated UFZ and the DBFZ: German Biomass Research Center, in German Deutsches Biomasseforschungszentrum gemeinnützige GmbH, abbreviated DBFZ. These German institutes lead the research and knowledge on the topic of carboxylates and AD in the literature. After the bibliographic review, agro-industrial residues were selected for the research, including filter cake from sugar cane processing and residues from cassava processing. In addition, the experimental routes were adapted and tested, with the determination of the important physico-chemical properties of the substrates and the inoculum, and the anaerobic digestion experiments in 30 reactors divided into two routes (Route A: active archaea and route B: inhibited archaea). A chromatographic (CG) method was selected for the quantification of carboxylic acids generated in the experiments. The CAs found in greater quantities were in the filter cake fermentation. The most significant values were observed for the contents of acetic acid and butyric acid, increasing on day 4 of the experiment from route A to route B in the case of acetic acid from 51 mg/gMSO to 294 mg/gMSO, and in the case of butyric acid from 15 mg/gMSO to 197 mg/gMSO. After this date, acetic acid levels remained in the same range, and butyric acid levels remained lower.