| abstract |
PROBLEM TO BE SOLVED: To reduce the water concentration in lactide in an apparatus and process for synthesizing lactide. SOLUTION: A lactic acid oligomer discharge valve 10 is closed, lactic acid is transferred to a lactic acid condensing apparatus 2, and concentration and condensation of lactic acid are advanced by heating and decompression to evaporate the generated water. Lactic acid, lactic acid oligomer and lactide are removed from the generated gas by the condensing device 11 and refluxed, and then the water concentration in the gas is measured by the pressure measuring device 12. After confirming that the water concentration is below a predetermined value, the lactic acid oligomer discharge valve 10 is opened, the lactic acid oligomer is transferred, depolymerized to produce gaseous lactide, and condensed and recovered. [Selection] Figure 2 |