Analysis of the effect of leaching conditions on emission characteristics and combustion efficiency of sugarcane trash briquettes

Open burning and direct use of raw sugarcane trash emit particulate matter and acid-forming species (CO, NO/NOx, SO₂) that drive smog, corrosion, and health risks. This study assesses whether water leaching, followed by densification into briquettes, can lower gaseous and particulate emissions while sustaining useful fuel performance. Sugarcane trash (CO 421) was collected, leached under controlled conditions of temperature, particle size, and contact time, and densified using a hydraulic piston press (18 MPa; DIN 54385:2016-08). Emissions testing used a portable flue-gas analyzer (DIN 33962; ASTM D6522-20) and EPA Method 5 for total suspended particulates (TSP). Responses included CO, NO, NOx, SO₂, flue-gas temperature (Tgas), TSP, and combustion efficiency. Effects of leaching temperature, time, and particle size were evaluated with ANOVA and regression models. Compared with unleached briquettes, leached briquettes reduced CO by 52.91%, NO by 26.43%, SO₂ by 22.50%, NOx by 14.62%, and TSP by 41.51%. Tgas increased by 9.96% and combustion efficiency improved by 8.42%. Particle size exerted the strongest and most consistent influence across responses, while leaching temperature and time were also significant for many outcomes. Overall, greater leaching severity (smaller particles, higher temperature, longer time) yielded cleaner combustion. Overall, leaching pretreatment effectively upgrades sugarcane trash into a cleaner-burning briquetted fuel, cutting key pollutants and boosting efficiency. Adoption can reduce open-burning impacts, mitigate slagging/corrosion in equipment, and support renewable-energy and public-health goals in sugarcane-growing regions. These results revealed that the leaching procedure greatly enhanced the feedstock's fuel characteristics; a corresponding decline in gaseous and particulate matter emissions was conspicuously visible.