Chemical characterization, hydrolysis and production of biofuels and humic acids from urban solid waste

Abstract

Food waste is increasing in the world and if this residue is inappropriate disposal cause serious problems in the environment, due to its toxicity for soil and water. Then, new technologies for the use of urban solid waste (USW) can decrease its damage for nature. There is also a strong interest in the development of fuels from renewable sources, aiming at lower environmental impacts than the widely used fossil fuels. In view of this, biomass from USW is known for its great potential as a source for biofuels and biomolecules production. Therefore, the present work aims to produce ethanol, biodiesel and humic acids from the organic portion of the USW. The proposed technology conforms to the concept of biorefinery, and it consists in the production of ethanol by enzymatic hydrolysis using glycoamylases produced by R. oligosporus in solid-state cultivation, followed by alcoholic fermentation by Saccharomyces cerevisiae. Following, the lipid portion will be extracted and submitted to a chemical transesterification process with the aim of the production of biodiesel. In addition, from the non-hydrolyzed fibrous fraction, will be performed an alkaline extraction of xylan, whose process also originates from the so-called humic acids, inputs that favor the quality of the soils. (AU)