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1、太原理工大学 硕士学位论文 煤中形态硫在热解过程中的转化和迁移规律 姓名：段玉亲 申请学位级别：硕士 专业：化学工艺 指导教师：赵炜 20100601 太原理工大学硕士研究生学位论文 I 煤中形态硫在热解过程中的转化和迁移规律 摘 要 本实验在常压固定床反应器中对五种煤样进行热解实验，采用定硫仪 测得气相中总硫，同时利用化学分析方法对三种中高硫煤热解前后的形态 硫进行了剖析，得出了以下主要结论： 煤热解产物的分布规律：在低温区（400） ，热解和加氢热解产物分 布差别不大，而低温氧化法处理的煤样，其挥发分量均有不同程度的提高。 随温度的增加，所有气氛下的失重率都增加。 煤热解过程中硫在气相中的
2、迁移规律： (1) 提高终温及使用还原性气氛均能促进挥发分的释出，从而促进气相 中硫的逸出。煤热解过程中挥发分和气相逸出总硫之间的关系与形 态硫的转化和迁移规律有关。 (2) 煤样在热解过程中气相逸出的硫峰分别在两个区间： 第一峰在 300 左右，第二个峰在 600750。300左右应属于不稳定的有机硫， 是脂肪族硫醇、聚硫醚、芳香族硫醚和二硫化物。在 600和 700 左右的硫逸出峰应属于稳定的有机硫，是黄铁矿、二芳基硫醚和噻 吩类含硫化合物。 (3) 当气相逸出总硫的相对含量小于或等于挥发分释出的相对含量时， 焦中全硫的含量大于或等于原煤中的全硫；而当气相逸出总硫的相 对含量大于或等于挥发
3、分释出的相对含量时，焦中全硫的含量小于 或等于原煤中的全硫。 煤热解过程中硫在固相中的迁移规律： (1) 煤低温热解时，于惰性气氛（N2）下相比较，对于煤中硫化铁硫而 太原理工大学硕士研究生学位论文 II 言，还原性气氛和空气气氛均能促进其分解，而还原性气氛的脱除 效果高于空气气氛；对于煤中有机硫而言，还原性气氛和空气气氛 均能促进其分解，而空气气氛的脱除效果高于还原性气氛。 (2) 硫化铁硫在 400已经开始分解，而且还原性气氛（H2，CO）能促 进其分解；600时所有气氛下硫化铁硫分解基本完成。 (3) 低于 600时， 不同煤阶中有机硫种类的不同致使气氛对有机硫分解 作用有异。800时三
4、种煤样仅在 H2气氛下能促进较稳定的有机硫 (如噻吩、聚芳基硫醚等)的分解。气相中硫主要是煤中有机硫热分解 的结果，与硫化铁硫的分解几乎没有影响。 (4) 在空气气氛下，硫酸亚铁、硫酸铜、硫酸镁和硫酸钙分解反应的起 始温度分别为 500、600、850和 1000左右。在空气气氛下， CaSO4中添加 17%（wt）Fe2O3能明显提高硫的转化率且降低其分解 的起始温度， 而添加 17% （wt） CuCl2的作用并不明显。 添加 17% （wt） 氧化铁或 50% （wt） 活性炭均能促进 CaSO4的热分解， 且产物以 CaS 为主。添加剂氧化铁须在还原性气氛下使用，而添加剂活性炭的使 用
5、与气氛无关。 关键字：煤热解，形态硫，CaSO4，添加剂 太原理工大学硕士研究生学位论文 III FORM SULFUR TRANSFORMATION DURING COAL PYROLYSIS AT VARIOUS GAS ATMOSPHERES ABSTRACT In this paper, the sulfur release characteristic of five bituminous coals undergoing the process of the temperature programmed pyrolysis at the H2， N2， CO and air atm
6、osphere respectively were studied used the fixed-bed quartz reactor, and the quantity of sulfur in the pyrolysis gas and char were measured carefully used the coulometric titration apparatus and chemical analysis. Based on the comparison of the variation of the sulfur forms in the coal before and af
7、ter pyrolysis experiments, the experimental results have been listed as follow: The product distribution regularities of coal pyrolysis were summarized. The product distribution of pyrolysis and hypyrolysis of coal was not significantly different, while the low-temperature oxidation of relative cont
8、ent of volatile matter increased in varying degrees. Temperature is the main factor to influence the coal pyrolysis. Increases with temperature, the weight loss rate of all the atmosphere increases. The migration regularities of gas phase sulfur of coal during pyrolysis were summarized. (1) Improvin
9、g the final temperature and using reductive atmosphere can promote the release of volatile matter, thus contributing to the escape of sulfur in gas phase. The relationship between volatile matter and total sulfur in gas phase of coal pyrolysis process was related to the rule of form sulfur transform
10、ation. (2) Peaks of sulfur in the gas phase during pyrolysis process of coal separately in two ranges: the first peak at about 300, and the second 太原理工大学硕士研究生学位论文 IV peak at 600750. The first peak should belong to the unstable organic sulphur, is aliphatic mercaptan, polyethylene sulfide, aromatic s
11、ulfide and disulfide. The second peak should belong to be part of a stable sulfur organic sulfur is pyrite, diaryl disulfide, and thiophene sulfur compounds. (3) When the relative content of total sulfur gas escaping less than or equal to the relative content of volatile matter releasing, the conten
12、t of sulfur in coke is greater than or equal to the total amount of sulfur in raw coal, And when the relative of the total sulfur gas escaping is greater than or equal to the relative content of volatile matter, the content of sulfur in coke less than or equal to the total amount of sulfur in raw co
13、al. The migration regularities of solid phase sulfur form of coal during pyrolysis were summarized. (1) The migration regularities of sulfur form during low-temperature pyrolysis process of coal were summarized. The pyrite sulfur transform was related to the atmosphere, that the pyritic sulfur will
14、easily react with the reductive atmosphere and air atmosphere under the pyrolysis process, led the the transform of pyrite will more easily under reductive atmospherethan air atmosphere. The organic sulfur transform was related to the atmosphere, that the organic sulfur will easily react with the re
15、ductive atmosphere and air atmosphere under the pyrolysis process, led the the transform of pyrite will more easily under air atmosphere than reductive atmosphere. (2) The migration regularities of sulfur form in the pyrolysis process of coal were summarized. The pyrite sulfur has begun to decompose
16、 at 400, and the reductive atmosphere including CO and H2 can promote its decomposition. While decomposition of pyrite sulfur completed at 600. 太原理工大学硕士研究生学位论文 V (3) Under 600, the different types of organic sulfur in the coal will causative different decomposition effects. When the temperature was more than 800, the decomposition of organic sulfur can be promoted only under the H2 atm
