A novel purification process for dodecanedioic acid by molecular distillation

A novel purification process is involved to obtain the high purity [> 99%(by mass)] dodecanedioic acid (DC12). 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 DC12. Under the optimum conditions, distilling temperature 180 °C, pressure 30 Pa and feed flow rate 700 ml·h− 1, the purity of DC12 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 to 99.22%. Additionally, the effect of pretreatment (re-crystallization) on distillation process was revealed through a series of comparative experiments.

Graphical AbstractThis figure is the scheme of a laboratory centrifugal short-path distillation unit Lab3 of Myers company, USA. The main part of the still consists of a conical evaporating rotator, vacuum equipment as well as feed, distillate and residue receivers. The rotator is enclosed in a glass bell jar providing a condensing surface. Evaporating rotator is heated by electric power with a controller inside to maintain a constant evaporating surface temperature. The material is heated and melted to a homogeneous mixture liquid before being pumped to the feed reservoir. When the system is stable (with static pressure and temperature), the mixture is fed to the center of evaporator after degassing. Once on the hot spinning surface, a thin film forms where the lower molecular weight materials evaporate.Figure optionsDownload full-size imageDownload as PowerPoint slide