气流床水煤浆气化系统中氯元素的分布

摘要

以神府煤为原料的气流床水煤浆气化装置作为对象,对其原煤、粗渣、细渣、制浆水和废水等样品进行取样并进行实验分析,得出了气化系统中氯元素的分布情况;用化工流程模拟软件Aspen Plus构建了系统的电解质模型,模拟计算了气化系统中氯元素的分布状况以及氯元素浓度在气化系统中的变化趋势.实验结果表明:计算得到气化炉内氯元素的转化率为93.86％;气化系统中大部分的氯元素以废水形式排出系统,粗细渣及其夹带溶液中占有一小部分,合成气中含氯很少;氯元素在煤中的赋存形态会影响它的释放过程,该煤中大部分以有机态存在,占有94.27％,易释放出去.模拟出的氯元素分布结果与实验分析结果基本保持一致,氯离子浓度最高的为出真空闪蒸的黑水中的450 mg/L.%Taking Shenfu coal as objective,the samples of coal,slag,ash,fresh water and waste water of the entrained-flow coal-water slurry gasification system were analyzed,and the chlorine distribution in the gasification system was obtained.Electrolyte non-random two-liquid model was employed to calculate the chlorine distribution of overall system by Aspen Plus.The results show that the chlorine conversion ratio is 93.86％ in this system.The most part of chlorine in gasification system is discharged in waste water,while a small part is in slag streams,and only little chlorine is in gaseous streams.The mode of the occurrence of chlorine in the coal impacts the release of chlorine.In Shenfu coal,most of chlorine in the coal is in organics,sharing 94.27％,which can be released easily.The simulation result basically agrees with the experimental data.The highest concentration of chlorine is 450 mg/L in the black water of vacuum flash outlet.