Casca de maracujá como matéria-prima para biorrefinarias

Abstract

Brazil is the world's largest producer of passion fruit (Passiflora edulis) and its processing generates countless tons of waste in industries that are improperly discarded, contributing to environmental pollution. Due to the favorable chemical composition of these agro-industrial residues, the present study proposes the use of yellow passion fruit peel in the production of sugars and chemicals with high added value for biorefineries. The chemical characterization of the biomass was carried out using standardized procedures of the American Society for Testing and Materials (ASTM), Renewable Energy Laboratory (NREL) and Association of Official Analytical Chemists (A.O.A.C.). The efficiency of ultrasound-assisted pre-treatment was analyzed in order to provide greater profitability and sustainability to the process. A complete factorial experimental design was carried out to obtain the optimal conditions varying concentration (2.5 and 5% of HCl; 4 and 8% of NaOH; and distilled water) and time (0.5 and 1 hour) for yield of sugars and increased accessibility to cellulose and hemicellulose. Subsequently, the efficiency of the pre-treated hydrolysis for the production of sugars and furan compounds, 5-hydroxymethylfurfural (HMF) and furfural (FF) was evaluated. The products obtained were analyzed using high performance liquid chromatography (HPLC), Fourier transform infrared spectrophotometry (FTIR) and X-ray diffractometer analysis (XRD). The optimized conditions for the pretreatment were 2.5% HCl, 4% NaOH and aqueous, in sonication times of 1 hour. The highest yields of glucose (0.5%), HMF (0.009%) and FF (0.09%) were recorded from hydrolysis pre-treated with 2.5% HCl in 1h. However, the low yields found in the pre-treated hydrolysis demonstrated the low efficiency of this step for the formation of high added value compounds for the biorefineries. Infrared spectra and diffractograms confirmed the efficiency of the hydrolysis. From the results obtained, it was concluded that the yellow passion fruit peel has potential for the production of sugars and furan compounds, making it possible to add value to the waste by promoting sustainability, in addition to generating extra income for large and small producers.