Pré-tratamento de coroa de abacaxi visando aproveitamento para produção de biocombustível

Abstract

With the strengthening of the circular economy concept, the discussions about waste management have expanded, aiming the chain valorization to minimize environmental impacts. Industrial residues are extensively studied as raw material for processes, that is because they have environmental and economic appeal, they are generated in abundance and do not depend on agricultural land for production. Pineapple crown is an abundant industrial lignocellulosic waste generated mainly in the food processing sector. The production of bioenergy and bioproducts using pineapple crown can be an interesting strategy and alternative to land disposal processes. However, because it is a lignocellulosic biomass, the pineapple crown presents high recalcitrance, resulting from a structural coating mostly composed of cellulose, hemicellulose and lignin, requiring pretreatment processes to increase the accessibility of the structure and enable the conversion into high value-added products. In this scenario, the objective of this study was to evaluate different pre-treatment techniques of pineapple crown aiming to increase the bioaccessibility of structural polysaccharides and the conversion to monomeric sugars via enzymatic hydrolysis. For this, the biomass was collected and characterized. Pretreatment was performed by thermal processes in autoclave and chemical processes using H2SO4, NaOH and sequential acid and alkaline processes. The recovery of cellulose in the pretreated solid varied depending on the pretreatment, with percentages from 39 to 80%, and the sequential (acid-alkali) pretreatments showed the highest percentage in cellulose content. Hydrolysis was conducted with an enzymatic cocktail of cellulases, and a hydrolysis yield of approximately 70% was obtained for the sequential pretreatment. The high cellulose content recovered in the solid enabled conversion into monosaccharides, which makes it possible to envision scenarios where this biomass could be evaluated as a feedstock for conversion into biofuels, as well as cellulose recovery for the production of bioproducts with industrial applicability.