Provided is a carbonate ester purification apparatus including a treatment part for mixing a first solution containing a carbonate ester and an acidic substance with an alcohol solution of a metal alcoholate to obtain a mixed solution containing a reaction product of the acidic substance and the metal alcoholate, a separation part for removing a metal salt contained in the reaction product from the mixed solution to obtain a second solution, and a distillation part for removing a component from the second solution, the component different in boiling point from the carbonate ester to obtain a carbonate ester solution, wherein a content of the metal alcoholate in the alcohol solution is 5 to 18 mass %.

Provided is a carbonate ester purification apparatus including a treatment part for mixing a first solution containing a carbonate ester and an acidic substance with an alcohol solution of a metal alcoholate to obtain a mixed solution containing a reaction product of the acidic substance and the metal alcoholate, a separation part for removing a metal salt contained in the reaction product from the mixed solution to obtain a second solution, and a distillation part for removing a component from the second solution, the component different in boiling point from the carbonate ester to obtain a carbonate ester solution, wherein a content of the metal alcoholate in the alcohol solution is 5 to 18 mass %.

Provided is a carbonate ester purification apparatus including a treatment part for mixing a first solution containing a carbonate ester and an acidic substance with an alcohol solution of a metal alcoholate to obtain a mixed solution containing a reaction product of the acidic substance and the metal alcoholate, a separation part for removing a metal salt contained in the reaction product from the mixed solution to obtain a second solution, and a distillation part for removing a component from the second solution, the component different in boiling point from the carbonate ester to obtain a carbonate ester solution, wherein a content of the metal alcoholate in the alcohol solution is 5 to 18 mass %.

A process for preparing a diaryl carbonate from a dialkyl carbonate and an aryl alcohol is disclosed. The process takes place in apparatus comprising at least two distillation columns, and at least one of the distillation columns is operated at subatmospheric pressure which is achieved using vacuum equipment.

A process for preparing a diaryl carbonate from a dialkyl carbonate and an aryl alcohol is disclosed. The process takes place in apparatus comprising at least two distillation columns, and at least one of the distillation columns is operated at subatmospheric pressure which is achieved using vacuum equipment.

A process for preparing a diaryl carbonate from a dialkyl carbonate and an aryl alcohol is disclosed. The process takes place in apparatus comprising at least two distillation columns, and at least one of the distillation columns is operated at subatmospheric pressure which is achieved using vacuum equipment.

A method for recovering organic carbonates in an electrolytic solution of a waste lithium ion battery is provided. The organic carbonates include a first carbonate and a second carbonate having a higher melting point and a higher boiling point than the first carbonate. The method includes performing a temperature adjustment process in which an internal temperature of a drier in which the waste lithium ion battery is accommodated is kept in a first temperature range, an internal temperature of a pipe extending to below the drier is kept in a second temperature range, and an internal temperature of a condenser connected to the drier via the pipe is kept in a third temperature range, and performing a recovery process of reducing internal pressures of the drier, the pipe, and the condenser from a normal pressure to a first pressure and recovering the first carbonate in the condenser.

A method for recovering organic carbonates in an electrolytic solution of a waste lithium ion battery is provided. The organic carbonates include a first carbonate and a second carbonate having a higher melting point and a higher boiling point than the first carbonate. The method includes performing a temperature adjustment process in which an internal temperature of a drier in which the waste lithium ion battery is accommodated is kept in a first temperature range, an internal temperature of a pipe extending to below the drier is kept in a second temperature range, and an internal temperature of a condenser connected to the drier via the pipe is kept in a third temperature range, and performing a recovery process of reducing internal pressures of the drier, the pipe, and the condenser from a normal pressure to a first pressure and recovering the first carbonate in the condenser.

A production method of a dialkyl carbonate, comprising two separation and purification steps (I) and (II), wherein, in the step (I), the concentration of the dialkyl carbonate in the mixture (A.sub.T) is from 25.00 to 95.00% by mass, and the temperature of column bottom is 115? C. or more, and in the step (II), the concentration of the dialkyl carbonate in the column bottom component (B.sub.B) is from 99.00 to 99.95% by mass, and the purity of the dialkyl carbonate in the side-cut component (B.sub.s) is 99.99% by mass or more.

A production method of a dialkyl carbonate, comprising two separation and purification steps (I) and (II), wherein, in the step (I), the concentration of the dialkyl carbonate in the mixture (A.sub.T) is from 25.00 to 95.00% by mass, and the temperature of column bottom is 115? C. or more, and in the step (II), the concentration of the dialkyl carbonate in the column bottom component (B.sub.B) is from 99.00 to 99.95% by mass, and the purity of the dialkyl carbonate in the side-cut component (B.sub.s) is 99.99% by mass or more.