Formation of Fine Particles (Pm10) from Zhundong High-Sodium Coal at Entrained Flow Gasification Condition in a Flat-Flame Burner Reactor

Zhundong coal has very high content of alkali metals and alkaline earth metals (AAEMs), which will product many fine particles with aerodynamic size less than 10 μm (PM10) during combustion and gasification, resulting in many ash related problems. In order to characterize property of fine particle of Zhundong high-sodium coal during entrained flow gasification, the formation of PM10 was investigated by a novel flat-flame assisted entrained flow reactor. Results show that the particle size distribution (PSD) of PM10 on mass concentration under entrained flow gasification condition showed three peaks distribution. PM0.1 (aerodynamic size less than 0.1 μm) was the dominant in fine particles on number concentration, and sodium was mainly enriched in forms of NaCl and sodium aluminosilicate, leading to formation of square and spherical fine particles. The increase of water vapor concentration promoted the formation of square fine particles because more AAEMs were released. In addition, the PM 10 presented the ultrafine, central and coarse modes distribution according to the content of Al. Finally, the formation mechanism of PM10 during Zhundong high-sodium coal entrained flow gasification was proposed based on mode division