A novel purification process is involved to obtain the high purity[>99%(by mass)]dodecanedioic acid(DC_(12)).It involves a re-crystallization followed by molecular distillation from the crude product.The objective ...A novel purification process is involved to obtain the high purity[>99%(by mass)]dodecanedioic acid(DC_(12)).It involves a re-crystallization followed by molecular distillation from the crude product.The objective of this study is to investigate general conditions,feed rate,distilling temperature and vacuum,necessary for centrifugal distillation of DC_(12).Under the optimum conditions,distilling temperature 180℃,pressure 30 Pa and feed flow rate700 ml·h^(-1),the purity of DC_(12) in the residence reached 97.55%with a yield of 53.18%by the analysis of gas chromatography.Multiple-pass distillation made a considerable contribution by improving the purity to99.22%.Additionally,the effect of pretreatment(re-crystallization) on distillation process was revealed through a series of comparative experiments.展开更多
Separation and purification of dodecanedioic acid (DDDA) from its homologous compounds were studied experimentally by falling film crystallization (FFC). The influences of various operation parameters, including cryst...Separation and purification of dodecanedioic acid (DDDA) from its homologous compounds were studied experimentally by falling film crystallization (FFC). The influences of various operation parameters, including crystallizing time, flow rate of melt and temperature of glycerine bath, on purity of DDDA and crystallizing rate were investigated. Over 99% (by mole) DDDA was obtained for a feed composition of 96% (by mole). The main factors affecting the separation efficiency are flow rate of melt and temperature of glycerine bath. The crystallizing layer of DDDA was further purified by sweating and blasting. A set of optimized operation data are provided for better understanding the mechanism of heat and mass transfer in FFC, and for further industrial application of DDDA purification process.展开更多
文摘A novel purification process is involved to obtain the high purity[>99%(by mass)]dodecanedioic acid(DC_(12)).It involves a re-crystallization followed by molecular distillation from the crude product.The objective of this study is to investigate general conditions,feed rate,distilling temperature and vacuum,necessary for centrifugal distillation of DC_(12).Under the optimum conditions,distilling temperature 180℃,pressure 30 Pa and feed flow rate700 ml·h^(-1),the purity of DC_(12) in the residence reached 97.55%with a yield of 53.18%by the analysis of gas chromatography.Multiple-pass distillation made a considerable contribution by improving the purity to99.22%.Additionally,the effect of pretreatment(re-crystallization) on distillation process was revealed through a series of comparative experiments.
文摘Separation and purification of dodecanedioic acid (DDDA) from its homologous compounds were studied experimentally by falling film crystallization (FFC). The influences of various operation parameters, including crystallizing time, flow rate of melt and temperature of glycerine bath, on purity of DDDA and crystallizing rate were investigated. Over 99% (by mole) DDDA was obtained for a feed composition of 96% (by mole). The main factors affecting the separation efficiency are flow rate of melt and temperature of glycerine bath. The crystallizing layer of DDDA was further purified by sweating and blasting. A set of optimized operation data are provided for better understanding the mechanism of heat and mass transfer in FFC, and for further industrial application of DDDA purification process.
