Methods and devices for separating catalyst from oxidation mixtures containing dibasic acids

Abstract

This invention relates to methods and reactor devices for controlling the oxidation of hydrocarbons to dibasic acids, in the presence of a catalyst and a monobasic acid, by removing the catalyst from the reaction mixture, outside the oxidation zone, after the oxidation has taken place at least partially. Initially, the catalyst is partially precipitated and removed by reducing the water level in the reaction mixture and/or subjecting the reaction mixture to a temperature, at which or over which catalyst precipitates. After the initial partial precipitation of the catalyst, the mother liquor remaining is subjected to a thermal treatment during which at least the major part of the monobasic acid is removed leaving behind molten dibasic acids, in which the remaining catalyst precipitates substantially in its totality, and it is removed. The precipitated catalyst in the two precipitation stages may be recycled in miscellaneous ways. From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.

What is claimed is:  
     
         1 . A method of removing catalyst from a reaction mixture containing one or more dibasic acids, the reaction mixture having been formed after reaction of a hydrocarbon with an oxidant in the presence of the catalyst, water, and a monobasic acid solvent, in an oxidation zone, the method being characterized by steps of: 
 (a) precipitating part of the catalyst in a first catalyst precipitation zone by removing water at least partially from the reaction mixture and/or controlling temperature to be adequately high for causing partial catalyst precipitation;    (b) removing the precipitated catalyst, thus forming a second mother liquor comprising dissolved catalyst, monobasic acid solvent, and one or more of dibasic acids;    (c) removing at least partially the monobasic acid solvent and melting the one or more dibasic acids until catalyst precipitates in a second catalyst precipitation zone; and    (d) removing the catalyst which precipitated in step (c).    
     
     
         2 . A method as defined in    claim 1   , further comprising a step of recycling the catalyst precipitated in step (b) to the oxidation zone.  
     
     
         3 . A method as defined in    claim 1   , further comprising a step of recycling the catalyst removed in step (d) to the first catalyst precipitation zone.  
     
     
         4 . A method as defined in    claim 2   , further comprising a step of recycling the catalyst removed in step (d) to the first catalyst precipitation zone.  
     
     
         5 . A method as defined in    claim 1   , further comprising a step of partially removing the one or more dibasic acids before step (a).  
     
     
         6 . A method as defined in    claim 2   , further comprising a step of partially removing the one or more dibasic acids before step (a).  
     
     
         7 . A method as defined in    claim 3   , further comprising a step of partially removing the one or more dibasic acids before step (a).  
     
     
         8 . A method as defined in    claim 4   , further comprising a step of partially removing the one or more dibasic acids before step (a).  
     
     
         9 . A method as defined in    claim 1    wherein the hydrocarbon comprises a compound selected from a group consisting of cyclohexane, cyclohexanone, cyclohexanol, cyclohexylhydroperoxide, and a mixture thereof, the oxidant comprises oxygen, and one of the dibasic acids comprises adipic acid.  
     
     
         10 . A method as defined in    claim 2    wherein the hydrocarbon comprises a compound selected from a group consisting of cyclohexane, cyclohexanone, cyclohexanol, cyclohexylhydroperoxide, and a mixture thereof, the oxidant comprises oxygen, and one of the dibasic acids comprises adipic acid.  
     
     
         11 . A method as defined in    claim 3    wherein the hydrocarbon comprises a compound selected from a group consisting of cyclohexane, cyclohexanone, cyclohexanol, cyclohexylhydroperoxide, and a mixture thereof, the oxidant comprises oxygen, and one of the dibasic acids comprises adipic acid.  
     
     
         12 . A method as defined in    claim 4    wherein the hydrocarbon comprises a compound selected from a group consisting of cyclohexane, cyclohexanone, cyclohexanol, cyclohexylhydroperoxide, and a mixture thereof, the oxidant comprises oxygen, and one of the dibasic acids comprises adipic acid.  
     
     
         13 . A method as defined in    claim 5    wherein the hydrocarbon comprises a compound selected from a group consisting of cyclohexane, cyclohexanone, cyclohexanol, cyclohexylhydroperoxide, and a mixture thereof, the oxidant comprises oxygen, and one of the dibasic acids comprises adipic acid.  
     
     
         14 . A method as defined in    claim 6    wherein the hydrocarbon comprises a compound selected from a group consisting of cyclohexane, cyclohexanone, cyclohexanol, cyclohexylhydroperoxide, and a mixture thereof, the oxidant comprises oxygen, and one of the dibasic acids comprises adipic acid.  
     
     
         15 . A method as defined in    claim 7    wherein the hydrocarbon comprises a compound selected from a group consisting of cyclohexane, cyclohexanone, cyclohexanol, cyclohexylhydroperoxide, and a mixture thereof, the oxidant comprises oxygen, and one of the dibasic acids comprises adipic acid.  
     
     
         16 . A method as defined in    claim 8    wherein the hydrocarbon comprises a compound selected from a group consisting of cyclohexane, cyclohexanone, cyclohexanol, cyclohexylhydroperoxide, and a mixture thereof, the oxidant comprises oxygen, and one of the dibasic acids comprises adipic acid.  
     
     
         17 . A method as defined in    claim 1    wherein the method further comprises a step of reacting at least one of the dibasic acids with a reactant selected from a group consisting of a polyol, a polyamine, and a polyamide in a manner to form a polymer of a polyester, or a polyamide, or a (polyimide and/or polyamideimide), respectively.  
     
     
         18 . A method as defined in    claim 17   , further comprising a step of spinning the polymer into fibers.  
     
     
         19 . A method as defined in    claim 4    wherein the method further comprises a step of reacting at least one of the dibasic acids with a reactant selected from a group consisting of a polyol, a polyamine, and a polyamide in a manner to form a polymer of a polyester, or a polyamide, or a (polyimide and/or polyamideimide), respectively.  
     
     
         20 . A method as defined in    claim 19   , further comprising a step of spinning the polymer into fibers.  
     
     
         21 . A method as defined in    claim 5    wherein the method further comprises a step of reacting at least one of the dibasic acids with a reactant selected from a group consisting of a polyol, a polyamine, and a polyamide in a manner to form a polymer of a polyester, or a polyamide, or a (polyimide and/or polyamideimide), respectively.  
     
     
         22 . A method as defined in    claim 21   , further comprising a step of spinning the polymer into fibers.  
     
     
         23 . A method as defined in    claim 8    wherein the method further comprises a step of reacting at least one of the dibasic acids with a reactant selected from a group consisting of a polyol, a polyamine, and a polyamide in a manner to form a polymer of a polyester, or a polyamide, or a (polyimide and/or polyamideimide), respectively.  
     
     
         24 . A method as defined in    claim 23   , further comprising a step of spinning the polymer into fibers.  
     
     
         25 . A method as defined in    claim 9    wherein the method further comprises a step of reacting at least one of the dibasic acids with a reactant selected from a group consisting of a polyol, a polyamine, and a polyamide in a manner to form a polymer of a polyester, or a polyamide, or a (polyimide and/or polyamideimide), respectively.  
     
     
         26 . A method as defined in    claim 25   , further comprising a step of spinning the polymer into fibers.  
     
     
         27 . A method as defined in    claim 12    wherein the method further comprises a step of reacting at least one of the dibasic acids with a reactant selected from a group consisting of a polyol, a polyamine, and a polyamide in a manner to form a polymer of a polyester, or a polyamide, or a (polyimide and/or polyamideimide), respectively.  
     
     
         28 . A method as defined in    claim 27   , further comprising a step of spinning the polymer into fibers.  
     
     
         29 . A method as defined in    claim 13    wherein the method further comprises a step of reacting at least one of the dibasic acids with a reactant selected from a group consisting of a polyol, a polyamine, and a polyamide in a manner to form a polymer of a polyester, or a polyamide, or a (polyimide and/or polyamideimide), respectively.  
     
     
         30 . A method as defined in    claim 29   , further comprising a step of spinning the polymer into fibers.  
     
     
         31 . A method as defined in    claim 16    wherein the method further comprises a step of reacting at least one of the dibasic acids with a reactant selected from a group consisting of a polyol, a polyamine, and a polyamide in a manner to form a polymer of a polyester, or a polyamide, or a (polyimide and/or polyamideimide), respectively.  
     
     
         32 . A method as defined in    claim 31   , further comprising a step of spinning the polymer into fibers.  
     
     
         33 . A method as defined in    claim 1   , further comprising a step of forming a third mother liquor after removing the precipitated catalyst in step (d), and recycling part of the third mother liquor back to the second catalyst precipitation zone.  
     
     
         34 . A method as defined in    claim 2   , further comprising a step of forming a third mother liquor after removing the precipitated catalyst in step (d), and recycling part of the third mother liquor back to the second catalyst precipitation zone.  
     
     
         35 . A method as defined in    claim 3   , further comprising a step of forming a third mother liquor after removing the precipitated catalyst in step (d), and recycling part of the third mother liquor back to the second catalyst precipitation zone.  
     
     
         36 . A method as defined in    claim 4   , further comprising a step of forming a third mother liquor after removing the precipitated catalyst in step (d), and recycling part of the third mother liquor back to the second catalyst precipitation zone.  
     
     
         37 . A method as defined in    claim 8   , further comprising a step of forming a third mother liquor after removing the precipitated catalyst in step (d), and recycling part of the third mother liquor back to the second catalyst precipitation zone.  
     
     
         38 . A method as defined in    claim 9   , further comprising a step of forming a third mother liquor after removing the precipitated catalyst in step (d), and recycling part of the third mother liquor back to the second catalyst precipitation zone.  
     
     
         39 . A method as defined in    claim 12   , further comprising a step of forming a third mother liquor after removing the precipitated catalyst in step (d), and recycling part of the third mother liquor back to the second catalyst precipitation zone.  
     
     
         40 . A method as defined in    claim 16   , further comprising a step of forming a third mother liquor after removing the precipitated catalyst in step (d), and recycling part of the third mother liquor back to the second catalyst precipitation zone.  
     
     
         41 . A method as defined in    claim 33    wherein the method further comprises a step of reacting at least one of the dibasic acids with a reactant selected from a group consisting of a polyol, a polyamine, and a polyamide in a manner to form a polymer of a polyester, or a polyamide, or a (polyimide and/or polyamideimide), respectively.  
     
     
         42 . A method as defined in    claim 41   , further comprising a step of spinning the polymer into fibers.  
     
     
         43 . A method as defined in    claim 38    wherein the method further comprises a step of reacting at least one of the dibasic acids with a reactant selected from a group consisting of a polyol, a polyamine, and a polyamide in a manner to form a polymer of a polyester, or a polyamide, or a (polyimide and/or polyamideimide), respectively.  
     
     
         44 . A method as defined in    claim 43   , further comprising a step of spinning the polymer into fibers.  
     
     
         45 . A method as defined in    claim 9   , further comprising a step of adding glutaric acid to the second catalyst precipitation zone.  
     
     
         46 . A method as defined in    claim 12   , further comprising a step of adding glutaric acid to the second catalyst precipitation zone.  
     
     
         47 . A method as defined in    claim 16   , further comprising a step of adding glutaric acid to the second catalyst precipitation zone.  
     
     
         48 . A method as defined in    claim 45    wherein the method further comprises a step of reacting at least one of the dibasic acids with a reactant selected from a group consisting of a polyol, a polyamine and a polyamide in a manner to form a polymer of a polyester, or a polyamide, or a (polyimide and/or polyamideimide), respectively.  
     
     
         49 . A method as defined in    claim 48   , further comprising a step of spinning the polymer into fibers.  
     
     
         50 . A method as defined in    claim 46    wherein the method further comprises a step of reacting at least one of the dibasic acids with a reactant selected from a group consisting of a polyol, a polyamine, and a polyamide in a manner to form a polymer of a polyester, or a polyamide, or a (polyimide and/or polyamideimide), respectively.  
     
     
         51 . A method as defined in    claim 50   , further comprising a step of spinning the polymer into fibers.  
     
     
         52 . A method as defined in    claim 47    wherein the method further comprises a step of reacting at least one of the dibasic acids with a reactant selected from a group consisting of a polyol, a polyamine, and a polyamide in a manner to form a polymer of a polyester, or a polyamide, or a (polyimide and/or polyamideimide), respectively.  
     
     
         53 . A method as defined in    claim 52   , further comprising a step of spinning the polymer into fibers.  
     
     
         54 . A reactor device for conducting an oxidation of a hydrocarbon to a dibasic acid in the presence of a catalyst and a monobasic acid solvent, in a reaction mixture, followed by a two-stage separation of the catalyst from the reaction mixture, the reactor device characterized by: 
 an oxidation chamber;    a first catalyst precipitation assembly connected to the reaction chamber, the first catalyst precipitation assembly comprising at least one of a de-watering station, and a first thermal treatment station; and    a second catalyst precipitation assembly connected to the first catalyst precipitation assembly, the second catalyst precipitation assembly comprising an evaporator and a second thermal treatment station.    
     
     
         55 . A reactor device as defined in    claim 54   , further comprising a dibasic acid precipitation station disposed between the oxidation chamber and the first catalyst precipitation assembly.  
     
     
         56 . A reactor device as defined in    claim 55   , further comprising a dibasic acid separator disposed between the dibasic acid precipitation station and the first catalyst precipitation assembly, the dibasic acid separator being connected to the first catalyst precipitation station through a first mother liquor line, through which first mother liquor, separated from the precipitated dibasic acid, may be transferred to the first catalyst precipitation assembly, the dibasic acid separator also being connected to a first solids removal line, through which the precipitated dibasic acid may be removed at least partially.  
     
     
         57 . A reactor device as defined in    claim 55    wherein the dibasic acid removal station comprises a flash-crystallizer.  
     
     
         58 . A reactor device as defined in    claim 54    wherein the dibasic acid removal station comprises a flash-crystallizer.  
     
     
         59 . A reactor device as defined in    claim 54   , further comprising a first catalyst separator disposed between the first catalyst precipitation assembly and the second catalyst precipitation assembly, the first catalyst separator being connected to the second catalyst precipitation station through a second mother liquor line, through which second mother liquor, separated from the precipitated catalyst, may be transferred to the second catalyst precipitation assembly, the first catalyst separator also being connected to a second solids removal line, through which the precipitated catalyst may be removed at least partially.  
     
     
         60 . A reactor device as defined in    claim 59   , further comprising a second catalyst separator disposed after the second catalyst precipitation assembly, the second catalyst separator being connected to a third mother liquor line, the second catalyst separator also being connected to a third solids removal line, through which the precipitated catalyst may be removed at least partially.  
     
     
         61 . A reactor device as defined in    claim 59    wherein the second solids removal line is connected to the oxidation chamber, so that precipitated catalyst from the first catalyst separator may be recycled to the oxidation chamber.  
     
     
         62 . A reactor device as defined in    claim 60    wherein the second solids removal line is connected to the oxidation chamber, so that precipitated catalyst from the first catalyst separator may be recycled to the oxidation chamber.  
     
     
         63 . A reactor device as defined in    claim 60    wherein the third solids removal line is connected to the first catalyst precipitation assembly, so that precipitated catalyst may be recycled from the second catalyst separator to the first catalyst precipitation assembly.  
     
     
         64 . A reactor device as defined in    claim 61    wherein the third solids removal line is connected to the first catalyst precipitation assembly, so that precipitated catalyst may be recycled from the second catalyst separator to the first catalyst precipitation assembly.  
     
     
         65 . A reactor device as defined in    claim 62    wherein the third solids removal line is connected to the first catalyst precipitation assembly, so that precipitated catalyst may be recycled from the second catalyst separator to the first catalyst precipitation assembly.  
     
     
         66 . A reactor device as defined in    claim 60    wherein the third mother liquor line is connected to a recycle mother liquor line, which in turn is connected to the second catalyst precipitation assembly, so that third mother liquor may be partially recycled from the second catalyst separator to the second catalyst precipitation assembly, if so desired.  
     
     
         67 . A reactor device as defined in    claim 61    wherein the third mother liquor line is connected to a recycle mother liquor line, which in turn is connected to the second catalyst precipitation assembly, so that third mother liquor may be partially recycled from the second catalyst separator to the second catalyst precipitation assembly, if so desired.  
     
     
         68 . A reactor device as defined in    claim 62    wherein the third mother liquor line is connected to a recycle mother liquor line, which in turn is connected to the second catalyst precipitation assembly, so that third mother liquor may be partially recycled from the second catalyst separator to the second catalyst precipitation assembly, if so desired.  
     
     
         69 . A reactor device as defined in    claim 63    wherein the third mother liquor line is connected to a recycle mother liquor line, which in turn is connected to the second catalyst precipitation assembly, so that third mother liquor may be partially recycled from the second catalyst separator to the second catalyst precipitation assembly, if so desired.  
     
     
         70 . A reactor device as defined in    claim 64    wherein the third mother liquor line is connected to a recycle mother liquor line, which in turn is connected to the second catalyst precipitation assembly, so that third mother liquor may be partially recycled from the second catalyst separator to the second catalyst precipitation assembly, if so desired.  
     
     
         71 . A reactor device as defined in    claim 65    wherein the third mother liquor line is connected to a recycle mother liquor line, which in turn is connected to the second catalyst precipitation assembly, so that third mother liquor may be partially recycled from the second catalyst separator to the second catalyst precipitation assembly, if so desired.  
     
     
         72 . A method as defined in    claim 1   , wherein the monobasic acid removed in step (c) is utilized in step (a) for removing the water from the reaction mixture.  
     
     
         73 . A method as defined in    claim 4   , wherein the monobasic acid removed in step (c) is utilized in step (a) for removing the water from the reaction mixture.  
     
     
         74 . A method as defined in    claim 5   , wherein the monobasic acid removed in step (c) is utilized in step (a) for removing the water from the reaction mixture.  
     
     
         75 . A method as defined in    claim 9   , wherein the monobasic acid removed in step (c) is utilized in step (a) for removing the water from the reaction mixture.  
     
     
         76 . A method as defined in    claim 12   , wherein the monobasic acid removed in step (c) is utilized in step (a) for removing the water from the reaction mixture.  
     
     
         77 . A method as defined in    claim 13   , wherein the monobasic acid removed in step (c) is utilized in step (a) for removing the water from the reaction mixture.  
     
     
         78 . A method as defined in    claim 19   , wherein the monobasic acid removed in step (c) is utilized in step (a) for removing the water from the reaction mixture.  
     
     
         79 . A method as defined in    claim 20   , wherein the monobasic acid removed in step (c) is utilized in step (a) for removing the water from the reaction mixture.  
     
     
         80 . A reactor device as defined in    claim 54   , further comprising means for re-circulating monobasic acid solvent from the evaporator to the de-watering station.  
     
     
         81 . A reactor device as defined in    claim 55   , further comprising means for re-circulating monobasic acid solvent from the evaporator to the de-watering station.  
     
     
         82 . A reactor device as defined in    claim 57   , further comprising means for re-circulating monobasic acid solvent from the evaporator to the de-watering station.  
     
     
         83 . A reactor device as defined in    claim 59   , further comprising means for re-circulating monobasic acid solvent from the evaporator to the de-watering station.  
     
     
         84 . A reactor device as defined in    claim 61   , further comprising means for re-circulating monobasic acid solvent from the evaporator to the de-watering station.