利用程序升温燃烧.在线质谱检测技术,考察了含K、Mg、Ca的氧化物及它们与潮州瓷土矿复合之后对一种无烟煤粉的燃烧与固硫的影响.实验燃烧气氛采用体积分数为21%的氧气与氩气的混合气体,结果表明,潮州瓷土矿对煤焦燃烧具有显著催化作用,而KOH、MgO、CaO物料或其与潮州瓷土矿复合之后则对煤的燃烧具有一定的阻燃作用.KOH、MgO、CaO物料具有不同程度的固硫作用,但与瓷土矿复合之后总体固硫效果变差.其原因在于这些碱性金属氧化物对瓷土矿及燃烧时所形成的煤焦具有促进烧结的作用,形成的致密煤焦难以燃烧,而这种难以燃烧的致密煤焦又可以在高温下促进硫酸盐的分解,降低固硫效率.
The investigation into the effect of K-, Mg- or Ca-containing composites with Chaozhou porcelain clay on the combustion and sulfur retention of a kind of anthracite coal powders was carried out at atmospheric pressure in the atmosphere of 21% O2 in argon gas. On-line mass spectrometer was used for the tracking analysis of possible species in gas stream post-reactor. It was found that Chaozhou porcelain clay promoted the combustion of the anthracite coal, especially of its coal char, whereas KOH, MgO, CaO and their composites with Chaozhou porcelain clay inhibited the coal combustion to some extent. The addition of KOH, MgO or CaO led to SO2 evolution at lower temperature, however, it became easier when KOH, MgO or CaO was incorporated into Chaozhou porcelain clay. The reason that the sulfidation products became unstable was attributed to the formation of densified coal char resulting from the promotion of alkaline oxide. The densified coal char required high temperature for combustion, and at this temperature, sulfidation products were reduced by char or CO resulting from the incomplete combustion of coal.