Thermogravimetric analysis of co-combustion of a bituminous coal and coffee industry by-products

Abstract

This study investigates the combustion characteristics of blends of bituminous coal (BC) with two by-products of the coffee industry, spent coffee ground (SCG) and coffee husk (CH), at 10, 30, and 50 wt% using a thermogravimetric analyzer (TGA). For comparison purposes, blends of BC and wood pellets (WP) at the same mass ratios were also investigated. The thermal behavior and fuel interactions in the blends during combustion were characterized by the ignition index (Di), combustion index (S), and potential synergistic effects. The interactions between the materials in the blends led to an enhancement of up to 93.5% and 128.5% in Di, and 175.2% and 96.35% in S of the bituminous coal when blended at 50 wt% with SCG and CH, respectively. Furthermore, clear synergistic effects were observed with the combustion of BC-SCG blends, whereas the combustion of BC-CH blends did not show any appreciable synergistic effects.