公开(公告)号：EP4339183A1

公开(公告)日：2024-03-20

申请号：EP22807545.3

申请日：2022-05-12

申请人： Refine Holdings Co., Ltd. ,  Spiber Inc.

发明人： FUJITA Tomoya ,  IWAFUNE Mitsuhiro ,  SUZUKI Takao ,  TAKEYAMA Tomokiyo ,  ISHIZAWA Hideki ,  ODA Akiyoshi ,  TAKAHASHI Hiroaki ,  OHNO Junya ,  NAKASHIMA Kouji ,  NOUMI Tadashi ,  ISHII Hideto

IPC分类号： C07C51/44 ,  C07C51/48 ,  C07C53/02

摘要： Provided is a method for recovering a carboxylic acid, by which method the carboxylic acid is separated from an aqueous solution containing water and the carboxylic acid and the separated carboxylic acid is obtained as a carboxylic acid anhydride. The method includes a) a first step of bringing the aqueous solution into liquid-liquid contact with a prepared extractant, the prepared extractant containing a component for extracting the carboxylic acid and a diluent to dissolve the component, b) a second step of distilling the prepared extractant that is subjected to the first step, azeotropically distilling the diluent in the prepared extractant and water, separating the distillate into an extractant component layer mainly containing the diluent and an aqueous layer and then discharging the aqueous layer, returning the extractant component layer mainly containing the diluent to the distillation step as reflux, and discharging the prepared extractant containing the carboxylic acid through a bottom of the column; and c) a third step comprising re-distilling the prepared extractant containing the carboxylic acid discharged by the second step, and returning, to the first step, the prepared extractant from which the carboxylic acid and water are removed, the prepared extractant being discharged through a bottom of the column, where the diluent in the prepared extractant have a minimum boiling azeotrope with water.