Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
  • B01J27/06—Halogens; Compounds thereof
  • B01J27/132—Halogens; Compounds thereof with chromium, molybdenum, tungsten or polonium
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C67/00—Preparation of carboxylic acid esters
  • C07C67/36—Preparation of carboxylic acid esters by reaction with carbon monoxide or formates
  • C07C67/38—Preparation of carboxylic acid esters by reaction with carbon monoxide or formates by addition to an unsaturated carbon-to-carbon bond
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
  • C07C51/10—Preparation of carboxylic acids or their salts, halides or anhydrides by reaction with carbon monoxide
  • C07C51/14—Preparation of carboxylic acids or their salts, halides or anhydrides by reaction with carbon monoxide on a carbon-to-carbon unsaturated bond in organic compounds

Definitions

• Carboxylic acids and their anhydrides and esters have a variety of uses in the chemical industry. For example, propionic acid and certain of its salts are used as preservatives in the animal feed and food industries.
• the anhydrides of propionic and butyric acids are used to manufacture cellulose esters that find a number of uses in the plastics industry.
• Acetyl compounds such as acetic acid, acetic anhydride and methyl acetate are manufactured by a very efficient process in which methanol and/or methyl acetate is carbonylated in the presence or absence of water, depending on the desired product.
• Aliphatic, carboxylic acids containing 8 or more carbon atoms are readily available from natural occurring substances such as natural occurring fats and oils.
• the second commercial process involves the oxidation of butane or unsaturated natural acids.
• Derivatives of carboxylic acids require an additional chemical processing step.
• a propionate ester can be made by esterifying propionic acid with alcohol, using a variety of catalysts known in the art;
• propionic anhydride can be prepared from propionic acid by an exchange reaction with acetic anhydride.
• Hydroxycarbonylation also referred to as hydrocarboxylation
• equation (3) represents a direct (one step) process for preparing carboxylic acids. More importantly, it offers an advantage in the direct production of derivatives such as esters and anhydrides of the lower carboxylic acids. As exemplified in equations (4) and (5) , these processes have the potential to directly generate a carboxylic acid derivative in a single step using an olefin and carbon monoxide, thus eliminating multiple processing steps.
• a catalyst system comprising (1) a nickel compound, (2) a Group 6 metal, i.e., chromium, molybdenum, or tungsten, (3) a trivalent phosphine, a trivalent amine or an alkali metal, and (4) a halide, e.g., an iodine compound, is described in U.S. Patents 4,372,889, 4,407,726, 4,625,055, 4,537,871, 4,335,058, 4,483,803, 4,354,036, 4,540,811.
• the toxicity of Ni(CO) 4 which is likely generated in the system, still represents a problem and a disadvantage.
• Patent 3,790,607 describes a high pressure process for carbonylating fluorocarbon iodides to esters using a series of metal carbonyls including carbonyl compounds of the Group 6 metals.
• the substrates in both cases are iodides, not olefins, and are used either stoichiometrically or demonstrate limited catalysis.
• U.S. Patent 4,558,153 describes the addition of formates to olefins using a catalyst comprising a Group 6 metal, a halide, and optionally, a phosphorus— containing promoter.
• the source of the carbonyl unit in the process described in that patent is formic acid or a formate ester which must be formed in a separate manufacturing operation.
• U.S. Patent 4,558,153 contemplate the addition of carbon monoxide to an olefin to generate the carbonyl unit. In fact, no carbon monoxide is used in most of the examples of the patent.
• Group 6 metal oxides especially tungsten oxide, formulated as W 2 0 5
• W 2 0 5 tungsten oxide
• the function of the Group 6 metal oxides is to act as strong acids and the reactions were carried out at very high pressures and temperatures, i.e., 193 bar (2800 psi; 19300 kPa) and 375°C.
• the invention described in Serial No. 08/509,309 is a process for preparing aliphatic carbonyl compounds such as carboxylic acids, alkyl and aryl esters of carboxylic acids, and anhydrides of carboxylic acids.
• the catalyst system in that invention contains, as a primary component, a Group 6 metal such as chromium, molybdenum, tungsten, or a mixture thereof and at least one secondary component.
• the present invention improves upon the catalyst system and process for carbonylating olefins in Serial No. 08/509,039 by adding a polar, aprotic solvent to the catalyst system to accelerate the process of forming the carbonylated olefins. Adding just 10 weight % of these materials may accelerate the process by a factor of 2— to 5—fold. Advantages are apparent: smaller reactors, lower catalyst concentrations, and/or lower reaction temperatures.
• the present invention sets forth an improved catalyst system and process for generating aliphatic carboxylic acids, esters, and anhydrides by carbonylating olefins.
• the improved catalyst system of the present invention comprises:
• At least one Group 6 metal such as molybdenum, chromium, tungsten or a mixture thereof ;
• a halide selected from the group consisting of chlorine, bromine or iodine
• a polar, aprotic solvent such as a tertiary amide, or oxides of organic sulfides.
• the polar, aprotic solvent in the catalyst system of the present invention accelerates the reaction significantly as compared to the process in Serial No. 08/509,039.
• useful components include tertiary amides of carboxylic acids, such as dimethyl acetamide and N—methyl pyrrolidinone, tertiary amides of inorganic acids, such as phosphoric acid, or oxides of organic sulfides.
• tertiary amides particularly dimethyl acetamide and N—methyl pyrrolidinone
• oxides of organic sulfides such as sulfolane, dimethyl sulfoxide, and dimethyl sulfone.
• the concentration of the polar aprotic solvent is important in determining the extent of the accelerated effect, but must be balanced with other factors, such as cost of the solvent and its separation.
• the concentration may range from 1—80 weight %; but a more preferred range is from 2—20 weight %.
• the present invention provides both an improved catalyst system and an improved process for preparing an aliphatic carbonyl compound such as carboxylic acids, alkyl and aryl esters of carboxylic acids, and anhydrides of carboxylic acids.
• the improved process comprises contacting carbon monoxide with a mixture comprising an olefin and a catalyst system comprising (1) a first component selected from at least one Group 6 metal, i.e., chromium, molybdenum, tungsten, or a mixture thereof and (2) a second component selected from at least one of:
• a polar, aprotic solvent under carbonylating conditions of temperature and pressure.
• the process is preferably carried out in the substantial absence of metals of Groups 8, 9 and 10, (i.e., Fe, Ru, Os, Co, Rh, Ir, Ni, Pd and Pt) and formic acid and formate esters.
• Advantages and benefits provided by the invention include: (1) eliminating expensive noble metals such as rhodium and iridium; (2) the substantial absence of nickel removes the potential problem of Ni(CO) 4 hazards while leading to higher reaction rates; and (3) the expectation that product separation and catalyst recycle will pose fewer problems.
• Another benefit of the present invention is that neither formic acid nor a formate ester is required to operate the process.
• the first component of the catalyst system above can be any of the Group 6 elements (IUPAC classification), i.e., chromium, molybdenum, tungsten, or a mixture thereof.
• Molybdenum is the most active element and, therefore, is preferred.
• the Group 6 metal can, in principle, be added as any of a variety of Group 6 metal—containing compounds, molybdenum is generally available in its various oxide forms or as its hexacarbonyl derivative. Molybdenum is best added as a zerovalent metal compound, of which molybdenum hexacarbonyl is the most widely available and lowest cost example.
• the catalytically—effective amount of the Group 6 metal can be varied widely but the concentration of the metal in the liquid reaction medium typically will be in the range of 0.1 mmol to 1 molar with a concentration of 5 mmol to 500 millimolar being preferred.
• these molar ranges correspond to weight concentrations of 10 to 96,000 ppm and 50 to 48,000 ppm Mo.
• Molybdenum concentrations of 1 mmol (96 mg)/L to 100 mmol (9.6 g)/L are particularly useful.
• the chloride, bromide, or iodide component can be added in any number of forms such as, for ex ⁇ imple, an alkyl halide, a hydrogen halide, a salt such as a halide salt of catalyst components (2) (ii) or (2) (iii) defined above, elemental halide, or any combination thereof.
• the halide component preferably is an iodide; and is best added as the corresponding alkyl iodide, such as ethyl iodide in the case of ethylene carbonylation, or as the hydrogen iodide.
• the atomic ratio of Group 6 metal:X ⁇ (wherein X is Cl, Br or I) is 1:1 to 1:1000, preferably 1:1 to 1:100.
• alkali metal compounds of component (2) (ii) include the halides, especially the iodides, and the alkyl carboxylates of lithium, potassium, rubidium, and/or cesium.
• Examples of the salts of quaternary organic compounds of a Group 15 element ((2) (iii)), i.e., nitrogen, phosphorus and arsenic, and the trisubstituted organic compound of a Group 15 element ((2)(iv)) include compounds have the general formulas
• R 2 , R 3 , R 4 and R 5 are hydrocarbyl groups containing up to 20 carbon atoms, Q is N, P or As and X is an anion. Because of their availability, the compounds containing nitrogen or phosphorus generally are preferred. Examples of the hydrocarbyl groups are alkyl of up to 20 carbon atoms including aryl substituted alkyl such as benzyl, cycloalkyl of 5 to 7 ring carbon atoms; and aryl such as phenyl and substituted phenyl such as tolyl. Examples of anion X include halogen.
• the quaternary organic compounds of a Group 15 element and the trisubstituted organic compound of a Group 15 element also may be an amine or a heterocyclic nitrogen—containing compound such as pyridine, quinoline, imidazole, N—methylpyridinium halide, N,N'—dimethylimidazolium halide, and the like; or a bis—phosphine compound such as 1,2— bis (diphenylphosphino) ethane.
• Examples of the trisubstituted phosphine oxides ((2)(v)) include compounds having the formula (III )
• the ratio of the components can vary widely.
• Acceptable catalytic systems employing, for example, Mo and I may use ratios of Group 6 metal: iodide:copromoter (i.e., copromoter being components 2(ii) through 2 (v) ) of at least 1:1:0.5 to approximately 1:100:20. Further, the ratio of components may be:
• Mo: I as being 1:0 to 1:1000, with the preferred range being 1:1 to 1:100, and the Mo: copromoter being defined as from 1:0 to 1:200, with the preferred ratio being 1:1 to
• Mo as being from 0.0001 to 3 molar, with the preferred level being from 0.005 to 0.5 M in the initial catalyst solution.
• components (2) (i) through (2) (v) may be used individually or in combination.
• the total amount of components (2) (ii) , (2) (iii) , (2) (iv) and (2) (v) that may be used range from 1 to 200, preferably 1 to 30 gram atoms [in the case of component (2)(ii)] or moles [in the case of components (2) (iii) , (2) (iv) and (2) (v) ] per gram atom of Group 6 metal.
• the optimal combination of secondary catalyst components depends to a great extent on the nature of the olefin reactant, the product being produced, and the resultant design considerations.
• a preferred catalyst system comprises (A) a Group 6 metal, especially molybdenum, (B 1 ) at least 1 iodine compound, (B 2 ) at least 1 component selected from an alkali metal salt, a salt of a quaternary phosphonium compound, a trisubstituted phosphine or a trisubstituted phosphine oxide and (C) a polar, aprotic solvent.
• the iodine compound(s) (B 1 ) may be provided as the iodide salt of any of the compounds constituting component (B 2 ) .
• iodine compound (B 1 ) more typically is provided as hydrogen iodide and/or an alkyl iodide, e.g., an alkyl iodide containing up to 8 carbon atoms.
• an alkyl iodide preferably will correspond to the olefin reactant, e.g., ethyl iodide when the olefin reactant is ethylene.
• a catalyst system consisting essentially of molybdenum as molybdenum hexacarbonyl, iodine as ethyl iodide, tetraalkyl ammonium iodide has been found to possess good to excellent activity and stability.
• preferred operating pressures may also be better defined.
• the reaction is relatively insensitive to the partial pressure of the olefin (such as in the case of ethylene) but inversely dependent upon carbon monoxide until the point at which the catalyst decomposes. Therefore, although Serial No. 08/509,039 defines the operating ranges of 8 to 346 bar absolute (800 to 34600 kPa) , with a preferred range of 18 to 104 bar absolute (1800 to 10400 kPa) the preferred range is better defined by the partial pressure of carbon monoxide alone. Thus, the process is operable over a range of 50-1000 psi (3.4—68 atm) , but a range of 70—400 psi (5—27.2 atm.) for the carbon monoxide pressure is preferred.
• the present carbonylation process generally may be carried out at temperatures in the range of 75 to 350°C, preferably 140 to 250°C, more preferably 140 to 225°C and most preferably 140°C to 200°C.
• the carbon monoxide may be employed in substantially pure form, as available commercially, but inert diluents such as carbon dioxide, nitrogen, methane, and noble gases can be present if desired.
• inert diluents does not affect the carbonylation reaction but their presence makes it necessary to increase the total pressure in order to maintain the desired CO partial pressure.
• the presence of minor amounts of water such as may be found in the commercial forms of the reactants is, however, entirely acceptable.
• the gas fed to the carbonylation process preferably comprises carbon monoxide containing up to 50 volume percent hydrogen. The presence of hydrogen has been found to have a favorable effect on the rate of carbonylation.
• the olefin can be selected from a long list of ethylenically—unsaturated compounds, e.g. olefins containing from 2 to 20 carbon atoms, there is a limitation inherent in the choice of olefin.
• the hydroxycarbonylation of higher olefins with the catalyst system described herein introduces a carboxyl or carboxylate group at any one of the carbons along the carbon chain.
• hydroxycarbonylation of 1—pentene gives mixtures of hexanoic acid, 2—methylvaleric acid, and 2—ethylbutyric acid.
• a means for controlling the distribution of products for olefins having 5 or more carbons has not yet been discovered.
• the utility of the present carbonylation process for the generation of higher acids is limited to systems in which the mixture is either tolerated or preferred.
• Internal olefins are also useful in this reaction, but again lead to mixtures of products.
• the preferred olefin reactants consist of C 2 —C 4 ⁇ —olefins, i.e., ethylene, propylene, and the butenes, where there are, at most, only two potential products that are readily separable. Ethylene is the most useful of these olefins.
• the process may be operated in a batch, semi- continuous or continuous mode.
• Hydroxycarbonylation rates can be enhanced dramatically by using production systems designed for very efficient mass transfer, especially when light (C 2 to C 4 ) olefins are employed.
• a second reaction component in addition to the olefin and CO, is required to generate product.
• These are selected from alkyl alcohols or phenols (to form esters) , water (to form carboxylic acids) , and carboxylic acids (to form carboxylic acid anhydrides) .
• these can be selected from aliphatic Cl—C18 alcohols and C6 through C20 phenolic compounds. More preferred aliphatic alcohols are those having 1 to X (?) carbon atoms, although methanol is the most preferred alcohol.
• carboxylic acid is used to generate a carboxylic acid anhydride
• the most preferred example for the conversion of a carboxylic acid to a carboxylic acid anhydride would be generating propionic anhydride from ethylene, propionic acid, and carbon monoxide.
• the process may be carried out in the presence of an organic solvent or diluent such as, for example, carboxylic acids and esters, hydrocarbons, e.g., octane, benzene, toluene, xylene and tetralin, or halogenated hydrocarbons such as the chlorobenzenes, e.g., tri— chlorobenzene, or carboxylic acids, or esters such as cellosolve acetate, and the like.
• a material may serve as both solvent and reactant.
• aliphatic carboxylic acid anhydrides may be prepared by carbonylating an olefin in the presence of a carboxylic acid under substantially anhydrous conditions.
• the carboxylic acid functions as both a process solvent and as a reactant.
• Mixtures of solvents can also be used, such as mixtures of ethyl propionate and propionic acid.
• the carboxylic acid when used, should preferably correspond to the acid, or the acid moiety of the anhydride, being produced since the preferred solvent is one that is indigenous to the system, e.g., propionic acid and/or ethyl propionate in the case of ethylene carbonylation.
• the solvent or diluent preferably has a boiling point sufficiently different from the desired product in the reaction mixture so that it can be readily separated, as will be apparent to persons skilled in the art.
• the reaction should be run in the presence of a minimum amount of corrosion metals.
• typical corrosion metals inhibit carbonylation rate. Therefore, as specified above, the carbonylation process is preferably operated in the substantial absence, e.g., less than 300 parts per million (ppm) , of the metals of Groups 8, 9 and 10, in general, and nickel and iron, in particular.
• the inhibition caused by nickel differentiates the present carbonylation process of this invention from the processes described in U.S. Patents 4,372,889, 4,407,726, 4,625,055, 4,537,871, 4,335,058, 4,483,803, 4,354,036, 4,540,811 where nickel is the primary component of the catalyst systems disclosed therein.
• the most apparent goal of the present invention is to prepare carboxylic acids containing 3 to 9 carbon atoms, preferably carboxylic acids containing 3 to 5 carbon atoms, and most preferably propionic acid, and the anhydride of such carboxylic acids by carbonylating the appropriate olefin.
• water is included in the carbonylation mixture comprising an olefin, an inert, organic solvent and a catalyst system according to the preceding description.
• the amount of water fed to the carbonylation zone is at least 1 mole per mole of olefin and preferably is from 1 to 3 moles of water per mole of olefin.
• carboxylic anhydrides are carried out under substantially anhydrous condition as is well known in the art.
• a mixture of carboxylic acids and anhydrides can be produced by carrying out the process in the presence of a limited amount of water.
• the present invention may be described by the following examples and comparative examples, which demonstrate the acceleration of the reaction rate due to the polar, aprotic solvent.
• Example 1 General Procedure. Generating Propionic Anhydride with an N—Methyl Pyrrolidinone Accelerated Mo(CO) 6 —Bu 4 PI Catalyst
• Hastelloy ® C overhead stirred autoclave was fitted with a high pressure condenser and a dip tube for removing samples during the course of the reaction. Gas mixtures were prepared in a stirred gas mix tank heated to
• Liquid samples are removed every 20 minutes for 5 hours and analyzed for ethyl iodide, ethyl propionate, propionic anhydride, and propionic acid content by GC using a Hewlett Packard 5890 GC containing a 25 m (0.25 mm ID, 0.25 micron film) Quadrex 007 FFAP Capillary Column with p—xylene as an internal standard. (A split injection was used to introduce the sample and sample detection was accomplished with TCD detector.) These components represented the only significant products and all other materials detectable by GC—MS were only present at trace levels. Gas samples were also removed hourly and analyzed by GC to insure that the gas mixture is consistent. The molar quantities of propionic anhydride (npan) formed were determined from the GC data using the following equation:
• X i weight fraction of the component (obtained from GC analysis)
• n pa ° moles of propionyl initially present
• Example 1 was repeated except the NMP was omitted. The reaction rate was only 1.4 moles/kg initial solution/hr (180 g/kg initial solution-h) .
• Example 2 Generating Propionic Anhydride with a Sulfolane Accelerated Mo(CO) 6 —Bu 4 PI Catalyst
• Example 1 was repeated except sulfolane was substituted for NMP.
• the reaction rate was 2.7 moles/kg initial solution/hr (350 g/kg initial solution—h) . This demonstrates the usefulness of a sulfur—based polar, aprotic solvent.
• Example 1 was repeated except tetrabutylammonium iodide was substituted for tetrabutylphosphonium iodide on a molar basis.
• the reaction rate was 5.4 moles/kg initial solution/hr (700 g/kg initial solution—h) .
• Example 3 was repeated except the NMP was omitted.
• the reaction rate was only 1.4 moles/kg initial solution/hr (180 g/kg initial solution-h) .
• Example 1 was repeated except sodium iodide was substituted for tetrabutylphosphonium iodide on a molar basis. The reaction rate was 2.3 moles/kg initial solution/hr (300 g/kg initial solution-h) . Comparative Example 3 - Generating Propionic Anhydride with an Mo(CO) 6 -NaI Catalyst in the Absence of a Polar Aprotic Solvent
• Example 4 was repeated except the NMP was omitted.
• the reaction rate was only 0.8 moles/kg initial solution/hr (100 g/kg initial solution—h) .
• Example 1 was repeated except pyridine was substituted for tetrabutylphosphonium iodide on a molar basis.
• the reaction rate was 3.8 moles/kg initial solution/hr (490 g/kg initial solution—h) .
• Example 5 was repeated except the NMP was omitted.
• the reaction rate was only 2.2 moles/kg initial solution/hr (290 g/kg initial solution—h) .
• Table 1 The results of the above examples are summarized in Table 1 below.
• Example 2 The same apparatus and general procedure described in Example 1 for generating propionic anhydride as was used, except the propionic acid was replaced with a mixture of 54 g (4.5 mol) H 2 0 and 510 g (8.5 mol) acetic acid (AcOH) .
• the AcOH is present as both solvent and internal standard.
• the liquid samples obtained were analyzed for ethyl acetate, ethyl propionate, acetic acid, propionic acid, and water by GC .
• np E ⁇ XF pa 7 ) + (X ep1 /102 3' n a o [3] [(X ea /88) + (X aa /60)]
• X weight fraction (obtained from GC analysis)
• Rates were determined over the span required to consume the entire portion of water added. Using this procedure, the rate of propionic acid generation was found to be 2.2 mol/kg-hr (160 g/kg-h) .
• Example 6 was repeated, except that the NMP was omitted. At 160°C, the rate of propionic acid formation was barely detectable and the reaction was repeated at 175°C, where the rate of propionic acid formation was only 0.6 moles/kg—hr (40 g/kg—hr) . This clearly demonstrates the ability to use the polar, aprotic solvents to achieve higher reaction rates at lower operating temperatures and further demonstrates that the process may be extended to generate other carboxylic acid derivatives.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Materials Engineering (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)

Applications Claiming Priority (5)

Publications (1)

Family

ID=26721805

Family Applications (1)

Country Status (3)

Families Citing this family (1)

Family Cites Families (5)

• 1998
  • 1998-04-07 KR KR1019997009239A patent/KR20010006160A/ko not_active Application Discontinuation
  • 1998-04-07 WO PCT/US1998/007018 patent/WO1998045038A1/en not_active Application Discontinuation
  • 1998-04-07 EP EP98914616A patent/EP0973610A1/de not_active Withdrawn

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events