多层流化床低阶煤分级热解提高焦油品质研究  

Study on improving tar quality from staged pyrolysis of low rank coal in multistage fluidized bed

作　　者：周琦[1,2,3,4] 

机构地区：[1]中国科学院过程工程研究所多相复杂系统国家重点实验室,北京100190 [2]煤炭科学技术研究院有限公司煤化工分院,北京100013 [3]煤炭资源高效开采与洁净利用国家重点实验室,北京100013 [4]国家能源煤炭高效利用与节能减排技术装备重点实验室,北京100013

出　　处：《煤炭科学技术》2016年第3期169-176,共8页Coal Science and Technology

基　　金：国家国际科技合作专项基金资助项目(2015DFA60320);国家自然科学基金资助项目(21376250;21406105);国家自然科学基金煤炭联合基金资助项目(U1361122);国家高技术研究发展计划(863计划)资助项目(2015AA050505)

摘　　要：为提高低阶煤热解焦油品质,提出了上部煤分级热解和下部半焦气化耦合的多层流化床低阶煤热解新工艺,在实验室多层溢流管式流化床中研究了操作模式(流化床层数分别为单层、双层、三层)、过量氧气系数、水蒸气煤比(质量比)等因素对热解产物产率和焦油品质的影响。结果表明:氧气和水蒸气作为气化剂可促进多环芳烃的裂解;高温区产生的重质焦油在经过上部床层时与热态半焦接触,在半焦催化作用下发生催化重整反应可提高焦油品质;随着流化床层数从单层增加到三层,热解气体和焦油产率增加,半焦产率下降,焦油的组分明显减少,焦油中轻油的产率逐渐增加,而酚油和洗油产率下降;轻油与酚油质量分数之和在流化床层数为三层时达到了99.49%。因此,通过多层流化床热解低阶煤可以获得轻质组分含量较高的焦油。In order to improve tar quality from pyrolysis of low rank coal,the new technique of low rank coal pyrolysis in multistage fluidized bed with coal staged pyrolysis in the upper stage and char gasification in the lower stage was proposed.The effects on products distribution and tar quality were investigated under the conditon of different operation mode（ the numbers of fluidized bed stages was single,double and three respectively）,excessive oxygen ratio and steam and coal mass ratio.The results showed that the oxygen and steam as gasifying agent could promote cracking of polycyclic aromatic hydrocarbon. The heavy tar species formed in the high temperature region was contacted with hot char when they passed the upper bed,which could be furtherly cracked and reformed under the catalysis of char to improve the tar quality. With increasing the number of stages from single to three,the yield of pyrolysis gas and tar,and the content of light oil increased,whereas the char yield,the amount of component of tar,the content of phenol oil and wash oil decreased. The content of both the light oil and phenol oil of tar obtained from the three-stage fluidized bed pyrolysis reached 99.49%.Therefore,the tar with high content of light oil could obtained by staged pyrolysis of low rank coal in multistage fluidized bed.

关 键 词：低阶煤 分级热解 多层流化床 煤气化 焦油品质 

分 类 号：TQ523[化学工程—煤化学工程]