高温烟气蒸发垃圾渗滤液膜浓缩液的挥发性有机物

化工进展CHEMICALINDUSTRYANDENGINEERINGPROGRESS2019年第38卷第5期高温烟气蒸发垃圾渗滤液膜浓缩液的挥发性有机物夏珺，蔡一地，张俊丰，黄妍（湘潭大学环境与资源学院，湖南湘潭411105）摘要：通过对比和分析不同温度、不同时间下垃圾填埋场中膜浓缩液蒸发的挥发特性和挥发性有机物的种类，研究了在其蒸发过程中的有机物挥发情况，并基于此设计了直接利用高温烟气先间壁换热再直接换热的一体化蒸发装置，通过对高温烟气温度、浸没深度、蒸发时间的优化，最终实现了烟气热能的高效利用和常压下的减压蒸发效果。结果表明：随着温度的升高，尾气中高沸点、长碳链的挥发性有机物的种类和挥发量增多。挥发性有机物主要为烷烃类，100℃以后，苯系物和醇酯类物质增加明显；温度为80℃，蒸发0.5h和1h，低分子量有机物大量释放，高沸点物质挥发较少；400℃、450℃、500℃、550℃温度下高温烟气蒸发时，液相蒸发温度在85℃左右，与尾气温差保持在5～6℃，传热传质快，且挥发性有机物的种类与直接蒸发结论基本一致，提高了在较低温蒸发状态下热能的高效利用。同时，该尾气经活性炭吸附处理后，剩余挥发性有机物少，效果明显。关键词：垃圾渗滤液；膜浓缩液；蒸发；挥发性有机物；反应器；传热中图分类号：X5文献标志码：A文章编号：1000-6613（2019）05-2485-06StudyofconstitutesofvolatileorganiccompoundsresultingfromhighexhaustgastemperatureevaporationoflandfillleachatemembraneconcentrateXIAJun，CAIYidi，ZHANGJunfeng，HUANGYan(CollegeofEnvironmentandResources,XiangtanUniversity,Xiangtan411105,Hunan,China)Abstract:Bycomparingandanalyzingthevolatilizationcharacteristicsandtypesofvolatileorganiccompoundsintheevaporationofmembraneconcentrateinlandfillatdifferenttemperaturesandtime,thevolatilizationoforganiccompoundsintheevaporationprocesswasstudied.Anintegratedevaporationdevice,whichutilizesthehigh-temperaturefluegasfirst-wallheatexchangeandthendirectheatexchange,wasdesigned.Throughtheoptimizationofthetemperature,immersiondepthandevaporationtimeofthehigh-temperaturefluegas,theefficientuseoffluegasthermalenergyandthedecompressionevaporationundernormalpressurearefinallyrealized.Theresultsindicatedthatthespeciesandtheconcentrationofvolatileorganiccompoundswithhighboilingpointsandlongcarbonchainsincreasedwiththeincreaseofevaporationtemperature.Itwasnoteworthythatthevolatileorganiccompoundsweremainlyalkanes.Whenthetemperatureexceeded100℃,theconcentrationofbenzeneseriesandalcohollipidsincreasedsignificantly.Whenthetemperaturewascloseto80℃andtheevaporationtimewas0.5hor1h,organiccompoundswithlowmolecularweightweresignificantlyreleased,however,theorganic化工进展2019年第38卷compoundswithhighboilingpointsexistedinfew.Whentheevaporationtemperatureat400—550℃,theliquidevapo