Use of biochar obtained from coffee grounds as adsorbent of dyes and solid biofuel

Abstract

Brazil is the world's largest coffee producer and the second largest consumer. In 2016, the coffee crop was one of the largest in the country's history. One of the main residues of the coffee industry is coffee grounds. They are a daily waste in almost all residences, shops, bars and restaurants. The high production ends up generating an accumulation of waste due to the low processing capacity of this material. Thus, this work had the objective of finding alternative uses for this waste, to add value through the production of solid biofuel and activated biochar to remove contaminants. These bioproducts, as well as being good alternatives to minimize production waste, reduce the use of petroleum and consequently emissions of greenhouse gases. Biochar was obtained by slow pyrolysis of coffee grounds. In order to evaluate the the fuel capacity, characterization was carried out through physical-chemical analyses to measure moisture, ash, volatile material and fixed carbon contents, and elemental analysis to determine theoretical calorific value. The activated biochar was also tested as an adsorbent of organic dyes.