摘要
在内耐火衬式流化床中,采用负载不同碱金属及配比催化剂的煤粉为原料,研究了煤粉催化气化过程,探索了自热方式为催化气化过程提供足够反应热的可能性,获得了维持煤气化装置连续稳定运行的工艺条件。经实验研究发现,通过燃煤自供热可为催化气化过程提供所需的能量,并维持炉温在所需温度范围;添加碱金属催化剂后,煤粉对应的着火温度有明显降低,且钾盐对煤粉着火点影响比钠盐显著。同时,催化剂负载量存在一个最佳值;添加催化剂后,维持系统稳定操作的温度范围降低了100～200℃,控制炉温在低于该温度范围内操作,可有效减少结渣;负载催化剂后在较低的气化温度下可实现较高的碳转化率和气化效率,实现装置的连续稳定运行。燃煤自供热的流化床催化气化装置的构建及开发,将解决现有催化气化技术经济性不佳及工程放大难的问题。
The catalytic coal gasification over catalysts with different species and loadings of alkali metals was carried out autothermally in a fluidized bed gasifier with refractory lining. The feasibility of using burning coal to provide enough reaction heat for the catalytic gasification and the operating conditions for keeping steady state running were studied. The results obtained are as following： the heat provided by burning coal can provide the required reaction heat for catalytic coal gasification process and maintain the gasifier temperature in an accepted range; adding alkali-metal compound as catalyst, the ignition temperature of coal decreases obviously, the K-Salt affects the ignition temperature more than the Na-Salt, and there is an optimal catalyst loading. The controllable operation temperature range of catalytic gasification is 100-200~C lower than that of without catalysts, when the gasifier is operated in above lower temperature ranges, the slagging can be reduced effectively and the continuously stable operation of the unit can be realized. Adding catalyst can achieve higher carbon conversion and gasification efficiency in lower temperature range. The construction and development of the autothermal gasification unit would solve the existed problems of existent catalytic gasification, such as the unfavored technical economy and difficulty of realizing scale up. The research on material balance, energy balance, reaction and flow characteristics of catalytic coal gasification process with autothermal fluidized bed can support its actual engineering scale-up design and operation.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2013年第5期798-804,共7页
Journal of Chemical Engineering of Chinese Universities
基金
国家科技支撑计划(2009BAA25B00)
973计划(2011CB201305)
国际科技合作专项(2011DFA60610)
关键词
流化床
煤
催化气化
碱金属
燃煤自供热
稳定运行
fluidized bed
coal
catalytic gasification： alkali metals
autothermal process
steady state operation
