煤炭地下催化气化特性及工艺的研究

发布时间：2018-05-26 01:35

本文选题：煤炭地下气化 + 催化热解　；参考：《北京科技大学》2015年博士论文

【摘要】：由于煤炭地下气化技术受煤层赋存状况、地质构造、水文地质条件等因素制约,地下煤制气的组成、热值以及产气稳定性都难以达到地面煤制气的效果,限制了该技术的商业化应用。本课题将催化气化原理应用到地下煤制气中用以提高一次荒煤气的质量。试验主要以三种典型煤样作为研究对象,设计了多功能地下气化催化剂添加装置和两种催化剂注入方法,选择碱金属和碱土金属作为主催化剂,利用卧式固定床反应器对煤的催化热解、煤焦催化气化进行了化学反应特性、动力学、热力学的研究并深入分析了催化作用机理,最后采用中试装置及线型分布式多孔注气点气化炉对无烟煤煤层进行了地下催化气化验证性试验。试验结果表明,利用地下催化剂注入法对煤进行催化反应,可以提高煤气质量和气化反应速率。具体概括如下：催化剂提高了热解过程中气态产物的产率和H2组分含量。基于比表面积测试、XRD、 SEM分析,催化剂使无烟煤比表面积增加并延缓了无烟煤的石墨化进程。催化作用后的煤焦表面较原煤、原煤焦产生了更多的孔道,并且表面粗糙度增加、反应活性能力提高。地下催化气化可以提高煤焦的碳转化率,增加有效气的含量。利用不同数学模型及对模型进行修正并基于Arrhenius方程计算得出：Ca(OH)2可使煤焦富氧-水蒸气气化反应较催化前的表观反应速率提高1.34-1.41倍,表观活化能下降31-33kJ·mol-1:添加复合催化剂Ca(OH)2-Na2CO3的表观活化能较添加Ca(OH)2下降10.44-16.10kJ·mol-1,且Ea与指前因子A存在线性补偿关系。利用线型分布式多孔注气点气化炉及采用不同工艺进行催化气化时,煤气组分较催化前更接近于热力学理论煤气,气化效率、燃烧区面积均优于常规气化,并且催化气化对地下炉一次荒煤气的脱硫及脱焦具有协同效应。催化点火可以提高煤层升温速率,并且温度变化趋势与数值模拟过程基本一致。
[Abstract]:Because coal underground gasification technology is restricted by coal seam occurrence condition , geological structure , hydrogeologic condition and so on , the composition , calorific value and gas production stability of underground coal gas are difficult to reach the effect of ground coal gas production , which limits the commercial application of this technology .

The experimental results show that the coal catalytic reaction can be carried out by using the underground catalyst injection method , so that the gas quality and the gasification reaction rate can be improved .

Based on the specific surface area test , XRD and SEM analysis , the specific surface area of anthracite is increased and the graphitization process of anthracite is delayed .

The apparent activation energy of Ca ( OH ) 2 - Na2CO3 can be increased by 1 . 34 - 1 . 41 times , and the apparent activation energy is decreased by 31 - 33 kJ 路 mol - 1 . The apparent activation energy of Ca ( OH ) 2 - Na2CO3 is decreased by 10.44 - 16.10kJ 路 mol - 1 than that before catalysis , and Ea has linear compensation relation with the former factor A .

A linear distributed multi - hole gas injection point gasification furnace and different processes are used for catalytic gasification , the gas components are closer to the thermodynamic theory coal gas before catalysis , the gasification efficiency and the combustion zone area are better than that of conventional gasification , and the catalytic gasification has a synergistic effect on the desulfurization and decoking of the primary raw coal gas in the underground furnace .
【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TD84

【共引文献】