化工学报2019，Vol.70Issue(8)：3113-3120,8.DOI:10.11949/0438-1157.20190336
高碱煤燃烧过程中亚微米颗粒物PM1的生成特性
PM1 formation characteristics during high-alkali coal combustion
摘要
Abstract
High alkali coal generally has a high alkali metal content, which is the main precursor for the formation of submicron particulate matter PM1 during coal combustion. However, the alkali and alkaline earth metals (AAEMs), especially Na, result in a large amount of fine particulate matter (PM1) formation during coal combustion. In this work, two kinds of typical Zhundong coal are selected, namely, ZD-1 and ZD-2. The pulverized coal is burned in an electrical heated drop-tube furnace with different temperature (1273 K, 1373 K, and 1473 K). The mass size distribution and concentration of the particulates are analyzed by low pressure impactor (LPI), and compositions are determined by energy dispersive spectrometry (EDS). The results indicate that the amounts of PM1 produced by the submicron particles gradually decreases with increasing the reaction temperature. The size of PM1 shifts to a smaller size. The formation of PM1 is mainly affected by mineral elements such as Na and S. As the temperature increased, the relative contents of Na and S decreases in PM1, and the relative contents of Ca, Fe and Si increase. The mass concentrations of Na and S in the collected particles depend upon the particle size, which are proportional to 1/D0p for the particle sizes less than 0.4 μm. The PM1 formation characteristics are mainly affected by the homogeneous nucleation and heterogeneous condensation of high concentrations of mineral elements, and the interaction between mineral elements with intermediate products during combustion. Active sites of oxygen formed by silicon-aluminum oxides at high temperature can efficiently capture Na vapor, thereby inhibiting PM1 formation. This is one of the main reasons for the reduction of PM1 at higher temperature.关键词
煤燃烧/碱金属/PM1/前体/质量粒径分布/吸附剂Key words
coal combustion/ alkali and alkaline earth metals/ PM1/ precursor/ mass size distribution/ sorbents分类
化学化工引用本文复制引用
赵京,张玉锋,魏小林,李腾,宾峰..高碱煤燃烧过程中亚微米颗粒物PM1的生成特性[J].化工学报,2019,70(8):3113-3120,8.基金项目
国家自然科学基金项目(51736010) （51736010）
