Coffee Biomass Residue as a Raw Material for Cellulose Production and Py-GC/MS Analysis

Coffee production generates large volumes of residue, reaching 32 million tons per year in Brazil alone. This study aimed to evaluate the parchment of coffee fruit, a residue from the coffee industry, in terms of its chemical composition and potential for kraft pulp production. The parchment was characterized with respect to its carbohydrate, lignin, extractive, and mineral contents. The substance was submitted to the kraft pulping process, targeting a kappa number of 25. The main findings of this study are the following: glycans (38.5%), xylans (21.6%), and lignin (27.1%) were the main components of the raw material, the extractive content was 4.5%, quite similar to those found for hardwood species used for pulp production, and the pulping yield was 42.6%. The lignins from the residual were extracted and characterized by their chemical composition, obtained by elemental and pyrolysis-gas-chromatography-mass-spectrometry (Py-GC/MS) analyses. Py-GC/MS analysis from the decomposition of lignin provided the identification of 26 compounds, categorized into six different groups-acids, aldehydes, amines, furans, ketones, and aromatics. Based on chemical biomass characteristics, the pulping performance was similar to those observed for softwood raw materials, with similar pulp bleachability. These results indicate that the evaluated waste biomass has a good potential for use in pulp production.{GRAPHIACAL ABSTRACT}