Preparation and SO2 capture kinetics of a DeSOx coating for the desulfurization of exhaust emission

Xing Li; Taoli Huhe; Tao Zeng; Xiang Ling; Zhenpeng Wang; Hongyu Huang; Yong Chen

doi:10.1016/j.heliyon.2022.e11463

Preparation and SO₂ capture kinetics of a DeSO_x coating for the desulfurization of exhaust emission

Heliyon. 2022 Nov 7;8(11):e11463. doi: 10.1016/j.heliyon.2022.e11463. eCollection 2022 Nov.

Authors

Xing Li^{1

2

3}, Taoli Huhe^{1

4}, Tao Zeng^{2

3}, Xiang Ling¹, Zhenpeng Wang^{2

3}, Hongyu Huang^{2

3}, Yong Chen^{1

2}

Affiliations

¹ School of Mechanical and Power Engineering, Nanjing Tech University, Nanjing 211800, China.
² Chinese Academy of Science, Guangzhou Institute of Energy Conversion, Guangzhou 510640, China.
³ Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China.
⁴ Institute of Urban and Rural Mining, Changzhou University, Changzhou 213164, China.

Abstract

Sulfur dioxide (SO₂) is an extremely harmful pollutant in diesel engine exhaust fumes, which must be controlled and removed effectively. In order to better integrate desulfurization materials into diesel exhaust systems, a new desulfurization powder coating (DeSO_x coating) was prepared. The SO₂ capture performance and kinetics of the DeSO_x coating were subsequently studied. This study used a fixed-bed reactor to test the DeSO_x coating SO₂ capture performance and conduct kinetic analysis at various temperatures and gas flows. The analysis obtained the kinetic parameters of the activation energy and Arrhenius constant, with the derived rate control equations, under isothermal conditions. The DeSO_x coating and filter which were prepared using metal oxide powders, SiO₂ colloidal sol, and additives, exhibited an enhanced SO₂ capture performance. In this experiment, an MnO₂/SiO₂/LiOH coating had the best SO₂ removal rate and capture capacity at 400 °C. Under a reaction space velocity of 10700 h^-1, the MnO₂/SiO₂/LiOH coating SO₂ removal rate was 100% within the first hour of reaction. Under a reaction space velocity of 32000 h^-1, the MnO₂/SiO₂/LiOH coating SO₂ capture capacity was 132.7 mg_SO2/g_material during the second hour of reaction. The SO₂ capture conversion rate of the DeSO_x coating and filter follows the second-order kinetic mechanism model. For the MnO₂/SiO₂/LiOH coating, the Arrhenius equation gives an activation energy of 4952 J/mol and the Arrhenius natural logarithmic constant is 8.969 s^-1. For the MnO₂/SiO₂/LiOH filter, the activation energy of the rate constant is 214 J/mol, and the Arrhenius natural logarithmic constant is 3.744 s^-1. Therefore, the desulfurization coating is an effective way to remove SO₂ pollutants from diesel exhaust gases.

Keywords: Desulfurization coating; Exhaust desulfurization; Kinetic analysis; Sulfur dioxide capture.