用高露点空气干燥小木块时挥发性有机物的释放

编号 zgly0000342538

文献类型 期刊论文

文献题名 用高露点空气干燥小木块时挥发性有机物的释放

学科分类 220.5550;木材加工与人造板工艺学

作者 IngeJohansson  TobiasKarlsson  RolandWimmerstedt 

作者单位 S.E.P.ScandinavianEnergyProjectAB  BrorNilssonsg.16  SE-41755Goeteborg  Sweden  ThurneTeknikAB  Heliosvaegen1b  SE-12030STOCKHOLM  Sweden  ChemicalEngineering  LundUniversity  P.O.Box124  SE-22100LUND  Sweden 

母体文献 Chinese Journal of Chemical Engineering;中国化学工程学报: 英文版 

年卷期 2004,12(6)

页码 767-772

年份 2004 

分类号 TS652 

关键词 高露点空气  干燥  小木块  挥发性有机物  木材加工 

文摘内容 Emission of volatile organic compounds (VOCs) during drying of wood particles for particleboard manufacture, or for production of refined biofuels, is a potential environmental problem. The aim of this work is to study the emissions of VOCs during drying, and the influence on the emissions by different drying parameters.The experiments have mainly been done in a batch fluidized bed dryer, but measurements have also been done in a, pilot scale, continuous fluidized bed dryer. The parameters studied are air flow rate through the bed, air temperature, air dewpoint, and bed height. Since the present trend in biofuels and particle drying is towards very high dewpoints during drying, some measurements have been maxte at dewpoints up to 95~C, corresponding to a water content of 3.2kg water per kilogram dry air. The emissions have been measured in two different ways,online during drying with a flame ionization detector and through wood analyses of the terpene content in the wood particles before and after drying. Substantial work has been maxte in developing the latter method as well as developing the drying equipment to be able to produce a wide range of conditions of the drying medium. It was shown that the VOCs emitted, during wood particle drying, mainly consist of terpenes. The behavior of the emissions was typical, at first contact with the drying gas a sharp peak in the release rate was detected. After that,the release rate stabilizes and declines slowly to a point where the material temperature increases and results in a second small peak in the release rate. Typically 80%--90% of the initial terpene content in the material was emitted during drying to low moisture content and it is not possible to significantly influence this release by changing the drying conditions. Up to 50% of the emitted terpenes are released during a very short period after contact with the drying medium. This fact could be utilized by employing a 2-step drying process. The fact that the VOC concentration in the inert gas gets much higher when drying at higher dewpoints could be taken into consideration when dealing with closed loop applications where the inert gas after the dryer is burnt。