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).sub.nOR.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.

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).sub.nOR.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.

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).

Process for preparing metal alkoxides by means of transalcoholization, wherein a lower metal alkoxide is fed via a side feed into a reactive distillation column comprising a rectifying section situated above the feed and a stripping section situated below the feed; a higher alcohol is fed into the stripping section, the bottom and/or a bottoms circuit of the column; a solution of a higher metal alkoxide in the higher alcohol is taken off at the bottom of the column and/or from the bottoms circuit; and a vapor comprising lower alcohol is taken off at the top of the column, the vapor is at least partially condensed and a substream of the condensate is recycled to the top of the column as reflux. The process enables the preparation of metal alkoxides with a reduced energy requirement.

The magnesium alkoxide particle contains the reaction product of the following components: 1) a magnesium powder; 2) a mixed alcohol; 3) a halogenating agent; and 4) a titanate compound. The magnesium alkoxide particle is used for preparing a catalyst for olefin polymerization.

A method of making an olefin polymerization catalyst carrier with a general structure formula of Mg(OR.sup.I).sub.n(OR.sup.II).sub.2-n, wherein: 0n2, and R.sup.I and R.sup.II can be the same or different and are each independently selected from a C.sub.1-C.sub.20 hydrocarbon group by reacting an alcohol with a metal magnesium powder under the protection of nitrogen in the presence of a halogen or a halogen-containing compound to obtain a first product, and subjecting the product to a treatment pressure of from 0.2 to 5.0 MPa at a treatment temperature of from 80 to 200 C. for a duration of between 2 minutes and 6 hours. Also provided is a method of making an olefin polymerization solid catalyst component which includes the catalyst carrier, a titanium compound, and at least one electron donor compound.

A method of making an olefin polymerization catalyst carrier with a general structure formula of Mg(OR.sup.I).sub.n(OR.sup.II).sub.2-n, wherein: 0n2, and R.sup.I and R.sup.II can be the same or different and are each independently selected from a C.sub.1-C.sub.20 hydrocarbon group by reacting an alcohol with a metal magnesium powder under the protection of nitrogen in the presence of a halogen or a halogen-containing compound to obtain a first product, and subjecting the product to a treatment pressure of from 0.2 to 5.0 MPa at a treatment temperature of from 80 to 200 C. for a duration of between 2 minutes and 6 hours. Also provided is a method of making an olefin polymerization solid catalyst component which includes the catalyst carrier, a titanium compound, and at least one electron donor compound.

The present invention relates to a process for workup of a methanol/water mixture which is employed in the production of alkali metal methoxides in a reaction column. The mixture is distillatively separated in a rectification column. The vapours obtained at the upper end of the rectification column are compressed in at least two stages and the energy of the vapours compressed in each case is advantageously transferred to bottoms and side streams of the rectification column. This allows particularly energy-efficient use of the energy of the compressed vapours in the process according to the invention.

The process for workup of a methanol/water mixture is employed in the production of alkali metal methoxides in a reaction column, wherein methanol and alkali metal hydroxide solution are reacted with one another in countercurrent in a reaction column. Alkali metal methoxide dissolved in methanol is withdrawn at the lower end and a methanol/water mixture which is worked up with the workup process according to the invention is withdrawn at the upper end. The energy of the compressed vapours may additionally be used for operating the reaction column or for operating a reaction column in which a process for transalcoholization of alkali metal alkoxides is performed.

The present invention relates to a process for workup of a methanol/water mixture which is employed in the production of alkali metal methoxides in a reaction column. The mixture is distillatively separated in a rectification column. The vapours obtained at the upper end of the rectification column are compressed in at least two stages and the energy of the vapours compressed in each case is advantageously transferred to bottoms and side streams of the rectification column. This allows particularly energy-efficient use of the energy of the compressed vapours in the process according to the invention.

The process for workup of a methanol/water mixture is employed in the production of alkali metal methoxides in a reaction column, wherein methanol and alkali metal hydroxide solution are reacted with one another in countercurrent in a reaction column. Alkali metal methoxide dissolved in methanol is withdrawn at the lower end and a methanol/water mixture which is worked up with the workup process according to the invention is withdrawn at the upper end. The energy of the compressed vapours may additionally be used for operating the reaction column or for operating a reaction column in which a process for transalcoholization of alkali metal alkoxides is performed.