The present disclosure relates to the formation of dimethyl terephthalate (DMT). The present invention also relates to the depolymerization of polyethylene terephthalate (PET) and the recovery of dimethyl terephthalate (DMT).

The present disclosure relates to the formation of dimethyl terephthalate (DMT). The present invention also relates to the depolymerization of polyethylene terephthalate (PET) and the recovery of dimethyl terephthalate (DMT).

A method can be used for producing alkali metal alcoholates in counter flow by reactive rectification. The alkali metal is selected from sodium and potassium. In a first part of the method, the alcohol is converted in counter flow with the respective alkali metal hydroxide. In a second part of the method, the mixture of alcohol and water obtained is separated in a rectification column, and the alcoholic vapour arising is condensed, as a result of which the temperature thereof increases. The energy dissipated during cooling of the condensed vapour is then used in the first part of the method. This permits an energy-efficient production of the alkali metal alcoholates concerned.

A method can be used for producing alkali metal alcoholates in counter flow by reactive rectification. The alkali metal is selected from sodium and potassium. In a first part of the method, the alcohol is converted in counter flow with the respective alkali metal hydroxide. In a second part of the method, the mixture of alcohol and water obtained is separated in a rectification column, and the alcoholic vapour arising is condensed, as a result of which the temperature thereof increases. The energy dissipated during cooling of the condensed vapour is then used in the first part of the method. This permits an energy-efficient production of the alkali metal alcoholates concerned.

A method can be used for producing alkali metal alcoholates in counter flow by reactive rectification. The alkali metal is selected from sodium and potassium. In a first part of the method, the alcohol is converted in counter flow with the respective alkali metal hydroxide. In a second part of the method, the mixture of alcohol and water obtained is separated in a rectification column, and the alcoholic vapour arising is condensed, as a result of which the temperature thereof increases. The energy dissipated during cooling of the condensed vapour is then used in the first part of the method. This permits an energy-efficient production of the alkali metal alcoholates concerned.

A process produces sodium and/or potassium alkoxides in countercurrent by reactive rectification. Alcohol is reacted in countercurrent with the respective alkali metal hydroxide. The vapours containing alcohol and water are separated into at least two serially arranged rectification columns. The energy of the vapour obtained in the first rectification is utilized for operating the second rectification. This specific energy integration coupled with establishing a certain pressure difference in the two rectification stages makes it possible to cover a particularly large proportion of the energy required for the rectification through electricity and to save heating steam.

A process produces sodium and/or potassium alkoxides in countercurrent by reactive rectification. Alcohol is reacted in countercurrent with the respective alkali metal hydroxide. The vapours containing alcohol and water are separated into at least two serially arranged rectification columns. The energy of the vapour obtained in the first rectification is utilized for operating the second rectification. This specific energy integration coupled with establishing a certain pressure difference in the two rectification stages makes it possible to cover a particularly large proportion of the energy required for the rectification through electricity and to save heating steam.

A process produces sodium and/or potassium alkoxides in countercurrent by reactive rectification. Alcohol is reacted in countercurrent with the respective alkali metal hydroxide. The vapours containing alcohol and water are separated into at least two serially arranged rectification columns. The energy of the vapour obtained in the first rectification is utilized for operating the second rectification. This specific energy integration coupled with establishing a certain pressure difference in the two rectification stages makes it possible to cover a particularly large proportion of the energy required for the rectification through electricity and to save heating steam.

A process produces sodium and/or potassium alkoxides in countercurrent by reactive rectification. Alcohol is reacted in countercurrent with the respective alkali metal hydroxide. The vapours containing alcohol and water are separated into at least two serially arranged rectification columns. The energy of the vapour obtained in the first rectification is utilized for operating the second rectification. This specific energy integration coupled with establishing a certain pressure difference in the two rectification stages makes it possible to cover a particularly large proportion of the energy required for the rectification through electricity and to save heating steam.

One or more concentrated low-viscosity solutions of alkaline earth alkoxide compounds M(OCH.sub.2R.sup.6).sub.2-a-b(OR.sup.7).sub.a[O(CHR.sup.8)OR.sup.9].sub.b in mixture with a metal alkyl compound M(R.sup.10R.sup.11) in an aprotic solvent and related methods are disclosed herein.