负载型K_2CO_3/Al_2O_3吸收剂鼓泡床吸收CO_2特性及数值模拟  

Reaction Characteristics and Numerical Simulation of K_2CO_3/Al_2O_3 Sorbents for CO_2 Capture in a Fluidized-bed Reactor

作　　者：张中林[1] 刘道银[1] 董伟[1] 吴烨[1] 陈晓平[1] 孟庆敏[2] 

机构地区：[1]能源热转换及其过程测控教育部重点实验室(东南大学),江苏省南京市210096 [2]南京工程学院电力仿真与控制工程中心,江苏省南京市210013

出　　处：《中国电机工程学报》2015年第7期1674-1680,共7页Proceedings of the CSEE

基　　金：高等学校博士学科点专项科研基金(20130092110006)~~

摘　　要：利用负载型K2CO3/Al2O3吸收剂吸收燃煤电厂烟气中的CO2是一种较好的CO2减排方法。在小型鼓泡床试验台上对K2CO3/Al2O3吸收剂吸收CO2的特性进行了研究。结果表明,K2CO3/Al2O3吸收剂具有良好的CO2吸收性能,吸收剂转化率超过70%,在反应开始3min内CO2的脱除率达到了100%。基于K-L鼓泡床两相模型建立了负载型K2CO3/Al2O3吸收剂鼓泡床吸收CO2的数学模型,化学反应源项采用了颗粒缩核模型。CO2脱除率和K2CO3/Al2O3吸收剂转化率的模拟值与试验值较吻合,同时模型给出反应气体在气泡相和乳化相中的浓度分布,揭示了反应器某些细节特征。利用所建立的模型对试验系统进行了分析计算,结果表明,增加CO2浓度不利于提高CO2脱除率。增加流化数,气泡速度和直径均迅速增大,CO2脱除率迅速降低。增加床料量有利于提高CO2脱除率。模型的预测结果具备一定的合理性和准确性,为开展相应的试验研究和系统设计提供了基础数据。The K2CO3/Al2O3 sorbent is a good choice for CO2 capture from coal-fired power plant. The CO2 capture characteristics were investigated in a bubbling fluidized bed. The K2CO3/Al2O3 sorbent showed a good performance on CO2 capture in a bubbling fluidized bed. The conversion rate of sorbent was over 70% and the CO2 removal ratio was 100% at the first 3 min of the reaction. Based on the K-L two phases model, a modified model was established for the test system, in which a shrink-core model of single particle was used. The modeling and test values of sorbent conversion rate and CO2 removal ratio agreed well. At the same time, the distribution of CO2 concentration in the bed was given by the model. The prediction data showed that it was disadvantaged for the increase of CO2 removal ratio when the CO2 concentration in the gas was increased. Also, the model data showed that the fluidization number had a great influence on CO2 removal ratio. The bubble velocity and diameter increased quickly with the increase of the fluidization number, while the CO2 removal ratio decreased. Increasing sorbent amount was advantageous to improve the CO2 removal ratio. The model had a certain rationality and accuracy, which provided the basic data for further experimental study and system design.

关 键 词：K2CO3/Al2O3 鼓泡床 二氧化碳 捕集 K-L两相模型 

分 类 号：TK09[动力工程及工程热物理]