Organic compounds -- part of the class 532-570 series – Organic compounds – Oxygen containing
Reexamination Certificate
2000-03-15
2001-10-16
Killos, Paul J. (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Oxygen containing
C568S451000, C568S453000, C560S177000, C558S085000, C556S013000, C556S025000
Reexamination Certificate
active
06303829
ABSTRACT:
BRIEF SUMMARY OF THE INVENTION
1. Technical Field
This invention relates to improved metal-organophosphorus ligand complex catalyzed processes. More particularly this invention relates to metal-organophosphorus ligand complex catalyzed processes in which the desired product, along with any organophosphorus ligand degradation products and reaction byproducts, can be selectively extracted and separated from the reaction product fluid by fractional countercurrent extraction.
2. Background of the Invention
It is known in the art that various products may be produced by reacting one or more reactants in the presence of an metal-organophosphorus ligand complex catalyst. However, stabilization of the catalyst and organophosphorus ligand remains a primary concern of the art. Obviously catalyst stability is a key issue in the employment of any catalyst. Loss of catalyst or catalytic activity due to undesirable reactions of the highly expensive metal catalysts can be detrimental to the production of the desired product. Moreover, production costs of the product obviously increase when productivity of the catalyst decreases.
For instance, a cause of organophosphorus ligand degradation and catalyst deactivation of metal-organophosphorus ligand complex catalyzed hydroformylation processes is due in part to vaporizer conditions present during, for example, in the vaporization employed in the separation and recovery of the aldehyde product from the reaction product mixture. When using a vaporizer to facilitate separation of the aldehyde product of the process, a harsh environment of a high temperature and a low carbon monoxide partial pressure than employed during hydroformylation is created, and it has been found that when a organophosphorus promoted rhodium catalyst is placed under such vaporizer conditions, it will deactivate at an accelerated pace with time. It is further believed that this deactivation is likely caused by the formation of an inactive or less active rhodium species. Such is especially evident when the carbon monoxide partial pressure is very low or absent. It has also been observed that the rhodium becomes susceptible to precipitation under prolonged exposure to such vaporizer conditions.
For instance, it is theorized that under harsh conditions such as exist in a vaporizer, the active catalyst, which under hydroformylation conditions is believed to comprise a complex of rhodium, organophosphorus ligand, carbon monoxide and hydrogen, loses at least some of its coordinated carbon monoxide, thereby providing a route for the formation of such a catalytically inactive or less active rhodium. Accordingly, a successful method for preventing and/or lessening such degradation of the organophosphorus ligand and deactivation of the catalyst as occur under harsh separation conditions in a vaporizer would be highly desirable to the art.
Organophosphorus ligand degradation and catalyst deactivation of metal-organophosphorus ligand complex catalyzed hydroformylation processes can occur under process conditions other than vaporizer conditions. The buildup of organophosphorus ligand degradation products as well as reaction byproducts in the reaction product fluid can have a detrimental effect on the process, e.g., decreases catalyst efficiency, raw material conversion and product selectivity. Accordingly, a successful method for preventing and/or lessening such buildup of organophosphorus ligand degradation products and reaction byproducts in the reaction product fluid would be highly desirable in the art.
DISCLOSURE OF THE INVENTION
It has now been discovered that in metal-organophosphorus ligand complex catalyzed processes, the desired product, along with any organophosphorus ligand degradation products and reaction byproducts, can be selectively extracted and separated from the reaction product fluid by fractional countercurrent extraction. By the practice of this invention, it is now possible to separate the desired product, along with any organophosphorus ligand degradation products and reaction byproducts, from the reaction product fluid without the need to use vaporization separation and the harsh conditions associated therewith. This invention provides a highly desirable separation method which prevents and/or lessens degradation of the organophosphorus ligand and deactivation of the catalyst as occur under harsh conditions with vaporization separation. This invention also provides a highly desirable separation method which prevents and/or lessens the buildup of organophosphorus ligand degradation products and reaction byproducts in the reaction product fluid.
This invention relates in part to a process for separating one or more products from a reaction product fluid comprising a metal-organophosphorus ligand complex catalyst, optionally free organophosphorus ligand, said one or more products, one or more nonpolar reaction solvents and one or more polar reaction solvents, wherein said process comprises (1) subjecting said reaction product fluid to fractional countercurrent extraction with at least two immiscible extraction solvents, said at least two immiscible extraction solvents comprising at least one nonpolar extraction solvent and at least one polar extraction solvent, to obtain a nonpolar phase comprising said metal-organophosphorus ligand complex catalyst, said optionally free organophosphorus ligand, said one or more nonpolar reaction solvents and said at least one nonpolar extraction solvent and a polar phase comprising said one or more products, said one or more polar reaction solvents and said at least one polar extraction solvent, and (2) recovering said polar phase from said nonpolar phase; wherein (i) the organophosphorus ligand has a partition coefficient Kp1 between the nonpolar phase and the polar phase expressed as follows:
Kp1
=
Concentration of organophosphorus ligand
in the nonpolar phase after extraction
Concentration of organophosphorus ligand
in the polar phase after extraction
in which Kp1 is a value of greater than about 5, and (ii) the one or more products have a partition coefficient Kp2 between the nonpolar phase and the polar phase expressed as follows:
Kp2
=
Concentration of products in the
nonpolar phase after extraction
Concentration of products in the
polar phase after extraction
in which Kp2 is a value of less than about 2.0.
This invention relates in part to a process for separating one or more organophosphorus ligand degradation products, one or more reaction byproducts and one or more products from a reaction product fluid comprising one or more unreacted reactants, a metal-organophosphorus ligand complex catalyst, optionally free organophosphorus ligand, said one or more organophosphorus ligand degradation products, said one or more reaction byproducts, said one or more products, one or more nonpolar reaction solvents and one or more polar reaction solvents, wherein said process comprises (1) supplying said reaction product fluid from a reaction zone to a separation zone, (2) subjecting said reaction product fluid in said separation zone to fractional countercurrent extraction with at least two immiscible extraction solvents, said at least two immiscible extraction solvents comprising at least one nonpolar extraction solvent and at least one polar extraction solvent, to obtain a nonpolar phase comprising said one or more unreacted reactants, said metal-organophosphorus ligand complex catalyst, said optionally free organophosphorus ligand, said one or more nonpolar reaction solvents and said at least one nonpolar extraction solvent and a polar phase comprising said one or more organophosphorus ligand degradation products, said one or more reaction byproducts, said one or more products, said one or more polar reaction solvents and said at least one polar extraction solvent, and (3) recovering said polar phase from said nonpolar phase; wherein (i) the selectivity of the nonpolar phase for the organophosphorus ligand with respect to the one or more products is expressed by the following partition coefficient ratio Ef1:
Ef1
=
Partition coef
Argyropoulos John Nicholas
Briggs John Robert
Bryant David Robert
Kanel Jeffrey Scott
Lee Max Min
Killos Paul J.
Union Carbide Chemicals & Plastics Technology Corporation
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