Improving the Removal of Fine Particles in the WFGD System by Adding Wetting Agents

Fine particles removal with high efficiency by adding wetting agents in the desulfurization liquid was presented in a single tower and double-towers cascade WFGD (Wet Flue Gas Desulfurization) system. Three types of wetting agents, polyether silicone oil, Compound NO.3, and XHG-248, were selected based on the test results of interfacial tension and contact angle of wetting agents solution on the surface of coal-fired fine particles. Influences of liquid-to-gas ratio and desulfurization liquid temperature on the effect of wetting agents were investigated in this paper. The results show that desulfurization liquid temperature has a significant influence on the performance of wetting agents. The selected three wetting agents are found to be capable of enhancing the removal of fine particles to a different extent at a desulfurization liquid temperature of 15 degrees C both in the single tower and double-towers cascade WFGD system. However, only Compound NO.3 is effective at a desulfurization liquid temperature of 45 degrees C. The improvement of particle removal by adding wetting agents into the desulfurization liquid is also influenced by the L/G. With an increase of L/G particle removal efficiencies are enhanced first and then tend to slow down.