褐煤热改性提质耦合气化利用的实验研究

发布时间：2018-03-28 15:10

  本文选题：褐煤　切入点：热解提质　出处：《华中科技大学》2015年硕士论文

【摘要】：褐煤在我国储量丰富,但其水分高、热值低、自燃倾向高,运输和储存困难,无法直接利用,开发利用程度较低,褐煤“提质+气化”耦合利用不仅可以解决这些问题,还可以显著拓宽褐煤资源的利用范围。本文选取中国典型胜利褐煤(SL煤)作为研究对象,在固定床管式炉中进行等温和非等温提质后,对提质煤的物理化学结构特性、煤质特性进行表征,评价提质过程效率和分析提质过程的主要影响因素;针对褐煤“提质+气化”耦合利用方式,研究提质褐煤的气化反应性和产气能力,探究提质条件对提质煤气化特性的影响机制。此外,还对胜利褐煤的固有矿物及铁基催化剂对气化特性的影响进行了研究。得出了以下主要结论:1、温度和升温速率是提质过程的主要影响因素,温度决定了提质煤的产率和有机物成熟度,升温速率对提质煤化学组成和挥发分裂解形式有明显影响;提质温度升高,孔隙结构渐趋发达,但挥发分分解形成的大分子基团在一定条件下会对大孔和中孔造成一定堵塞;含氧官能团在550℃提质后基本分解完成,煤中部分杂环会在550℃以后分解形成脂肪族组织;在450℃-550℃温度区间内提质后,提质煤的物化结构特性发生本征性变化;2、提质过程中残留的挥发分组分对提质煤的化学活性有着明显的影响;提质温度导致气化反应性逐渐降低而提质升温速率会增加气化活性;提质煤的孔隙结构参数与气化反应性并无直接的对应关系,提质过程中大分子基团物质对孔隙造成的堵塞不会对气化活性造成影响;在气化过程中提质煤的比气化速率呈现先增大后降低的趋势;提质褐煤气化反应性与产气潜能存在矛盾关系,随着提质温度的升高,产气能力逐渐增大,同一终温下的非等温提质煤产气能力相似;450℃-550℃温度段是SL煤进行“提质+气化”耦合利用的关键温度段;3、水洗过程促进了气化剂分子和气化产物的扩散,有利于热解和气化反应的进行;盐酸洗去的矿物质组分对热解和气化过程有着显著的催化作用,而氢氟酸洗出的矿物质对气化过程有着一定的阻碍作用;铁基催化剂对SL煤的气化过程有着明显的催化效果,但催化剂添加量对催化效果的影响不够明显,其催化效果可能受其在煤中的分散程度影响。
[Abstract]:Lignite is rich in reserves in China, but its moisture content is high, calorific value is low, spontaneous combustion tendency is high, transportation and storage is difficult, it can not be used directly, and the degree of exploitation and utilization is low. The coupling utilization of lignite "improving quality gasification" can not only solve these problems. In this paper, the typical Shengli lignite SL coal in China is chosen as the research object. After isothermal and non-isothermal tempering in a fixed bed tube furnace, the physical and chemical structural characteristics of the extracted coal are studied. The characteristics of coal quality were characterized, the efficiency of the process was evaluated and the main factors affecting the process were analyzed, and the gasification reactivity and gas production capacity of lignite were studied according to the coupling utilization mode of lignite gasification. To explore the mechanism of the influence of the conditions on the gasification characteristics of coal. In addition, The effects of inherent minerals of Shengli lignite and iron based catalyst on gasification characteristics were also studied. The main conclusions are as follows: 1, temperature and heating rate are the main influencing factors in the process of upgrading. The temperature determines the yield and maturity of organic matter, and the heating rate has a significant effect on the chemical composition and volatile cracking form of the coal, and the pore structure becomes more and more developed as the temperature rises. However, under certain conditions, macromolecular groups formed by volatile decomposition will cause blockage of macropores and mesoporous cells, oxygen functional groups will basically decompose after upgrading at 550 鈩，

本文编号：1676860