Open Access

ARTICLE

Emission Behaviors of Submicron Particles (PM₁) Generated by the Combustion of Sesame Stalk after Combined Water Washing and Carbonization Pretreatment

Tianyu Liu¹, Chang Wen^1,2,3,*, Wenyu Wang¹, Kai Yan³, Yongjun Xia⁴, Rui Li³, Juan Liu⁴, Yang Zhang¹

1 State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
2 Department of New Energy Science and Engineering, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
3 China-EU Institute for Clean and Renewable Energy, Huazhong University of Science and Technology, Wuhan, 430074, China
4 State Grid Jiangxi Electric Power Science Research Institute, Nanchang, 330096, China

* Corresponding Author: Chang Wen. Email:

(This article belongs to the Special Issue: Advancement of Understanding of PM_2.5 and Hg Emissions and Their Control Technologies for Cleaner Combustion)

Energy Engineering 2021, 118(3), 473-485. https://doi.org/10.32604/EE.2021.014870

Received 04 November 2020; Accepted 16 December 2020; Issue published 22 March 2021

Abstract

Pretreatment before biomass combustion is significant for its efficient utilization and that combined water washing and carbonization can be efficient. An agricultural processing residues sesame stalk was selected and carried out two pretreatments separately, i.e., water washing-torrefaction (W-T) and torrefaction-water washing (T-W), to explore the effect on the fuel properties, combustion characteristics and particulate matter (PM) emission. The obtained biochar was also combusted under air and oxy50 (CO₂:O₂ = 50:50) conditions for the sake of investigating the effect of pretreatment and combustion atmosphere. The results indicate that, W-T and T-W both not only have great effect on the improvement of fuel properties but also reduce the content of water-soluble elements like K, Cl, etc. Due to the difference in hydrophobicity, the biochar obtained by W-T have the optimal fuel properties. At the same time, the pretreatment also hinder the combustion in a certain extent in which the comprehensive combustion characteristics (S_N) show a downward trend. Furthermore, both two pretreatments have obvious benefit on the reduction of PM₁ emission and W-T have the best effect related to the higher removal efficiency of inorganic elements (especially K + Na + Cl + S). Under oxy50 condition, the oxygen concentration and combustion temperature is higher, improving the sulfation of K and vaporization of Ca, P and Mg which result in weakening in the pretreatment reduction effect on PM₁ emission.

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