Method for reactivating a catalyst composition

Catalyst – solid sorbent – or support therefor: product or process – Regenerating or rehabilitating catalyst or sorbent – Treating with a liquid or treating in a liquid phase,...

Reexamination Certificate

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C502S031000, C502S033000, C502S056000

Reexamination Certificate

active

06683015

ABSTRACT:

BACKGROUND OF INVENTION
The present invention is directed to a method for reactivating a deactivated catalyst composition, and in particular to a method for reactivating a deactivated carbonylation catalyst composition, which is present in a post reaction mixture of a catalytic oxidative carbonylation reaction, and optionally recycling the re-activated catalyst composition in a subsequent oxidative carbonylation reaction without the need to individually isolate, purify, or reconstitute the original components of the catalyst composition.
A useful method for the production of aromatic carbonates includes the oxidative carbonylation of aromatic hydroxy compounds, with carbon monoxide and oxygen, which is typically catalyzed by a catalyst composition comprising a Group 8, 9 or 10 metal catalyst, various metal co-catalyst sources, a salt source, optionally an activating solvent, and optionally a base source. The lifetime of a typical carbonylation catalyst composition that can catalyze the production of aromatic carbonates, in an oxidative carbonylation reaction, is generally finite, thus resulting in a steady decrease in catalytic activity as the carbonylation reaction progresses. The decrease in catalytic activity is typically characterized by a steady decrease in the rate at which the desired aromatic carbonate is produced. Loss of catalytic activity during and after a carbonylation reaction can result from, but is not limited to, a change in reaction conditions (e.g., temperature, pressure), a decrease in the concentration of a reagent (e.g., oxygen), a change in the pH of the reaction mixture, an irreversible consumption of one or more components of the catalyst composition, and the build up of a particular side-product, which might act as a catalyst poison in the case of certain catalyst compositions.
The reactivation, and recycle, of a deactivated catalyst composition generally involves a removal step, a purification step, and a reconstitution step, wherein the individual components of the deactivated catalyst composition are first removed from a reaction mixture, purified, and then transformed into their original active forms before being recycled in a subsequent reaction. However, on a commercial scale these types of relatively complex processes are generally unattractive, because they result in the physical loss of unacceptable quantities of costly catalyst components. Consequently, a long felt yet unsatisfied need exists for a new and improved method for reactivating a deactivated catalyst composition previously used in an oxidative carbonylation reaction of an aromatic hydroxy compound, such that the re-activated catalyst composition can be re-used in a subsequent oxidative carbonylation reaction without the need to individually isolate, purify, and reconstitute the various components of the catalyst composition.
SUMMARY OF INVENTION
In one embodiment, the present invention is directed to a method for reactivating a deactivated carbonylation catalyst composition comprising a Group 8, 9 or 10 catalyst source, and a Group 14 metal first inorganic co-catalyst, which is present in a first liquid reaction mixture, said method comprising the following steps:
a first addition step, in which an aqueous solution comprising at least one protic acid source is added to said first liquid reaction mixture, forming a biphasic second liquid reaction mixture composed of an organic layer and an aqueous layer;
a mixing step, whereby the biphasic second liquid reaction mixture is effectively agitated for a predetermined amount of time, followed by a settling stage in order to repartition the mixture into the organic layer and the aqueous layer;
a first separation step, in which the organic layer of said biphasic second liquid reaction mixture is separated from said second liquid reaction mixture, to produce an aqueous third liquid reaction mixture;
an optional second separation step, in which any precipitate which was present in the denser phase of the second liquid reaction mixture is separated from the denser phase obtained after the first separation step;
an optional second addition step, in which any metal containing precipitate which was separated during the second separation step, is added to the third liquid reaction mixture to produce a fourth liquid reaction mixture; and
an evaporation step, wherein the volume of said fourth liquid reaction mixture is reduced by removing a predetermined amount of at least one component by evaporation at a predetermined temperature and pressure thus producing a concentrated fourth liquid reaction mixture;
wherein the carbonylation catalyst composition contained in the concentrated fourth liquid reaction mixture is more active, than the carbonylation catalyst composition contained in said first liquid reaction mixture, at carbonylating an aromatic hydroxy compound in a subsequent oxidative carbonylation reaction.
In another embodiment, the invention is directed to a method for reactivating a deactivated carbonylation catalyst composition comprising a Group 8, 9 or 10 catalyst source and a Group 14 metal first inorganic co-catalyst, which is present in a first liquid reaction mixture, said method comprising the following steps:
an optional first evaporation step, wherein the volume of the first liquid reaction mixture is reduced by removing a predetermined amount of at least one component by evaporation at a predetermined temperature and pressure to produce a concentrated first liquid reaction mixture;
a first addition step, in which an aqueous solution comprising at least one protic acid source is added to said first liquid reaction mixture, forming a biphasic second liquid reaction mixture composed of an organic layer and an aqueous layer;
a mixing step, whereby the biphasic second liquid reaction mixture is effectively agitated for a predetermined amount of time, followed by a settling stage in order to repartition the mixture into the organic layer and the aqueous layer;
a first separation step, in which the organic layer of said second liquid reaction mixture, is separated from said second liquid reaction mixture after a predetermined amount of time, to produce an aqueous third liquid reaction mixture;
an optional second separation step, in which any precipitate which was present in the denser phase of the second liquid reaction mixture is separated from the denser phase obtained after the first separation step;
an optional second evaporation step, wherein the volume of said aqueous third liquid reaction mixture is reduced by removing a predetermined amount of at least one component by evaporation at a predetermined temperature and pressure to produce a concentrated third liquid reaction mixture;
a second addition step, wherein a solution comprising at least one member selected from the group consisting of an activating solvent, an aromatic hydroxy compound, an aromatic carbonate, and any mixtures thereof is added to the third liquid reaction mixture, forming a fourth liquid reaction mixture;
a third evaporation step, wherein the volume of the fourth liquid reaction mixture is reduced by removing a predetermined amount of at least one component by evaporation at a predetermined temperature and pressure to produce a concentrated fourth liquid reaction mixture;
a third separation step, in which any components that precipitate from the concentrated fourth liquid reaction mixture after a predetermined amount of time are separated from the concentrated fourth liquid reaction mixture, therein producing a fifth liquid reaction mixture;
an third addition step, wherein at least one member selected from the group consisting of an aromatic hydroxy compound, an organic ligand source, an aromatic carbonate, a salt source, an activating solvent, a base source, and any mixtures thereof, is added to the fifth liquid reaction mixture to produce a sixth liquid reaction mixture; and
an optional fourth addition step, wherein any metal containing precipitate which was separated during the second separation step is added to the sixth liquid reaction mixture, therei

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