Energetic improvement of tanned leather solid wastes by thermal treatment

Abstract

The permanent increase of the world energy consumption based on fossil fuels has caused several problems around the globe, which cannot be overlooked anymore. The necessity of cleaner energy sources is mandatory; among the different possibilities, biomass and solid wastes have become remarkable materials because of the wide processes and fuels resulting of them. Annually, the leather industry in Colombia produces 3.324 tons and generates 700 tons of tanned solid wastes approximately. The lack of alternative disposal methods makes this industry hazardous, despite the different technologies evaluated worldwide, such as pyrolysis, gasification or biodigestion. This work aims to analyze the changes in the chemical composition of the remaining solid and to enhance the energetic value of

tanned solid wastes after thermal treatment in the 180-280°C range. The improvement of the high heating value is about 16%. Such parameter ups from 17 to 20,5 MJ kg-1. Hydrogen exhibits the highest variation after thermal treatment with a decomposition ratio of 0,102 mol C-1, while Sulfur, at 0,0021 mol C-1, is the most stable. The high concentration of the carbon content in the remaining char, about 47,8%, increases the opportunities to use this material as either a feedstock for subsequent energy systems, or as a precursor for activated carbon production.