Mitigation of particulate matter emissions from co-combustion of rice husk with cotton stalk or cornstalk

PM emission is one of key issues in the biomass combustion of heat and power plants. In this paper, rice husk (RH) was co-combusted with cotton stalk (CSK) or cornstalk (CS) to study the PM emission behaviors. The experimental results show that the addition decreases PM1 yields by 20.13-54.65% for CSK and 45.99-76.70% for CS in comparison to the CSK or CS combustion alone. A strong synergistic effect exists during the co-combustion process, which can appreciably inhibit the generation of fine particulate matter. The synergistic effect is caused by the physical dilution effect, and mainly by the reaction between alkali metals species in cornstalk/cotton stalk ash and Si-containing species in rice husk ash to inhibit the volatilization of alkali metals. However, the PM reduction degree is also affected by the ash chemistry, especially the Si/(Ca thorn Mg) ratio, as confirmed by the higher synergistic effect of rice husk/ cornstalk compared to rice husk/cotton stalk. The results suggest that co-combustion of biomass with high Si-containing rice husk is a promising approach to reduce PM1 emissions during biomass co combustion. (C) 2022 Elsevier Ltd. All rights reserved.

Automated summary

This study investigates the influence of co-combustion of rice husk with cotton stalk or cornstalk on PM emissions. The experimental results demonstrate a significant reduction in PM1 yields during the co-combustion process. The synergistic effect of physical dilution and chemical reactions between alkali metals and Si-containing species in the ash contributes to the inhibition of fine particulate matter generation. The Si/(Ca+Mg) ratio in the ash chemistry, especially for rice husk/cornstalk, plays a crucial role in the degree of PM reduction.