Slagging Characteristics of Co-Combustion of Water Hyacinth Biomass and Coal

Abstract

Due to the pollution caused by coal combustion for power generation and the low comprehensive efficiency of biomass direct combustion for power generation, biomass and coal co-combustion for power generation has become the future development trend. To mitigate the hazards of slagging in the actual production of coal and water hyacinth co-combustion for power generation, combined with slagging discrimination indices, X-ray fluorescence (XRF) and X-ray diffraction (XRD) were applied to study the effects of mixing ratios, temperature, and additives on the slagging characteristics of water hyacinth mixed anthracite combustion. At higher ashing temperatures, the K and Cl content in the ash was reduced, which helped to reduce slagging. CaO can compete with the fuel’s K and react preferentially with Si and Al, leading to reduced production of KAlSiO₄ and KAlSi₃O₈. Kaolinite can weaken the function of K as a Cl carrier, allowing K to form complex potassium aluminosilicates with Si and Al. According to the comprehensive analysis of six ash sample slagging indexes, water hyacinth ash is serious slagging, anthracite ash is medium slagging, and the co-combustion of water hyacinth and coal can change the degree of ash slagging to a certain extent. Kaolin has a better-mitigating effect than CaO in preventing the slagging of mixed ash. These findings provide a starting point for the combustion of aquatic biomass with coal.