Pan Danping

Fine Particle Characteristics from Limestone–Gypsum Desulfurization Process

In order to investigate the characteristics of fine particles formed during the limestone–gypsum desulfurization process, fine particle emissions with an experimental system were studied. The physical characteristics such as fine particle concentrations, morphology, and compositions, as well as the characteristics of fine particle formation mechanisms, were analyzed. The results show that large numbers of fine particles are formed during limestone–gypsum desulfurization process and the majority of them are in the submicron range. The fine particles formed during the limestone–gypsum flue gas desulfurization process are related to the particles in desulfurization slurry. The main composition of particles formed during the desulfurization is CaSO4. With the increase in SO2 concentration, the fine particle emission has little difference. The fine particles formed during desulfurization are mainly from the entrainment and evaporation of desulfurization slurry.

Study on Mechanisms of Aerosol Formation in Wet Ammonia-Based Desulfurization Process

A simulation ammonia wet flue gas desulfurization (WFGD) platform was built to simulate separately the two different aerosol formation mechanisms in ammonia WFGD process of inhomogeneous reaction and entrainment. The aerosol concentration and size distribution along with the morphology features and the chemical composition were tested and investigated with the electrical low-pressure impactor (ELPI), the pollutant PM sampler, the field emission scanning electron microscope (FESEM), and the aerosol mass spectrometer (AMS). The comparison was made of the numerical concentration size distribution of aerosols generated under the two different formation mechanisms and the typical ammonia WFGD process. The results showed that the inhomogeneous reaction mechanism is the dominating one of the two in ammonia WFGD, which produced the majority of the aerosols emitted from the scrubber, the most of which, if counted in numerical concentration, were submicron particles with the chemical ingredients consisting mainly of sulfates and ammonium and the size distribution based on numerical concentration being a bimodal one. While the entrainment mechanism had minor influences on aerosol formation in the ammonia WFGD, the aerosols generated under this mechanism were much larger than those generated under the inhomogeneous reaction. Great differences were found between the aerosols formed under the two mechanisms.