Utilização de biomassas lignocelulósicas da Amazônia Legal para produção de bioprodutos em um contexto econômico e socioambiental

Abstract

The objective of this study is to investigate the potential of green coconut biomass (mesocarp) for the production of levulinic acid (LA). Several methods have been applied to characterize this biomass physically and chemically, with regard to immediate chemical analysis, extractives, total lignin, infrared spectroscopy (FTIR) and liquid chromatography (HPLC), in order to provide an assertive direction in the use of this residue. The synthesis of LA was performed with different catalysts, hydrochloric acid (HCl), sulfuric acid (H2SO4), BMIMBr ionic liquid, and dichloromethane organic solvent (DCM). The conversion reactions were performed by varying time (t) and temperature (T). In order to increase the yield of LA, the biomass was pre-treated with sulfuric acid (H2SO4), sodium hydroxide (NaOH), and water (H2O in soxhlet) solutions. The maximum yield of LA was ≅43.85%, under the following reaction conditions: 3 h, 180 °C, and 4.5% (v/v) of hydrochloric acid (HCl). Besides levulinic acid, 5- hydroxymethylfurfural (HMF) and furfural (FF) were also quantified, with yields of ≅ 13.35% and ≅ 4.0%, respectively. The pre-treatments applied to the biomass were inefficient for levulinic acid production when compared to raw biomass synthesis. However, there were significant increases in the release of sugars, xylose, and arabinose (p < 0.05) after the pretreatments. The results demonstrated the potential of green coconut shells within biorefineries to produce value-added chemicals.