FRACIONAMENTO DE BIOMASSA LIGNOCELULÓSICA COM O USO DE SOLVENTES EUTÉTICOS NATURAIS PROFUNDOS NADES

Abstract

Brazil has a privileged position as a leader in the integral use of vegetable biomass because it has the largest biodiversity on the planet. Adding value to a refinery is associated with the treatment and disintegration of biomass components, and its conversion into intermediary products such as oils, sugars, and biogas. The chemical composition of wood varies according to the species, parts of the tree and environmental conditions. It is possible to separate them into two groups of chemical components: structural and non-structural (extractives). In this context, macromolecular substances such as cellulose, hemicelluloses and lignin are included. There are processes applied to biomass fractionation in which one or more biomass pre-treatment stages are required, with the purpose of removing or breaking down the lignin and hemicellulose layers, which allows enzymes to access cellulose more easily. Given this, the combination of different pre-treatments and enzymes for hydrolysis of biomass generates a wide diversity of technological routes and can be used alternative techniques that have been developed as the use of deep natural eutectic solvent (NADES). Thus, the objective of the present work was to perform the fractionation of the biomass of the bark of the eucalyptus species Urograndis in two fractions: Cellulose rich fraction (CRF) and Lignin rich fraction (LRF) using NADES. In this process three conditions were applied for the fractioning of biomass: conventional heating (100ºC), microwave radiation with power of 600W and 1000W and ambient temperature of 25ºC. The percentages obtained through conventional heating were 72.25% of CRF, 27.75% of LRF; 72.54% of CRF with microwave radiation at a power of 1000W, 27.46% of LRF. For the treatment applied the radiation at a power of 600W were obtained: 70.61% of CRF and 29, 39% of LRF. The techniques used for characterization of LRF were infrared spectroscopy FT-IR and X-ray diffractometry for crystallinity analysis and scanning electron microscopy SEM. For characterization of LRF the techniques were used: UV-vis and FT-IR.Total crystallinity index (TCI) ,lateral order index (LOI) and hydrogen bonding intensity( HBI) were calculated . The use of NADES a low cost, sustainable organic solvent combined with microwave radiation proved to be efficient for the fractionation of biomass in these fractions