JPH0217946A - Manufacture of molybdenum alkylene glycole complex useful as epoxy-oriented catalyst - Google Patents

Abstract

PURPOSE: To facilitate the epoxidation of an olefin by mixing ethylene glycol with ammonium dimolybdate in a specified ratio in a reactor, bringing the mixture into reaction at elevated temp. and pressure and returning the reaction mixture to atmospheric conditions. CONSTITUTION: Ethylene glycol is mixed with ammonium dimolybdate in a reactor so that the molar ratio of ethylene glycol to the number of gram atoms of molybdenum is regulated to 7:1 to 20:1. The mixture is heated at 25-100 deg.C and while reducing the pressure to 5-100 mmHg, for 5-60 min under agitation while removing a vaporizing reaction byproduct. The reaction mixture is returned to atmospheric conditions and the unreacted ethylene glycol is recovered from the resultant molybdenum/ethylene glycol complex having 10-15 wt.% molybdenum content and not substantially contg. solid matter to obtain the objective catalytically active molybdenum complex.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing molybdenum compounds, and more particularly to an improved method for producing molybdenum alcohol complexes useful as olefin epoxidation catalysts.

The epoxidation of olefins to obtain various epoxide compounds has been studied for a long time by those skilled in the art. It is well known that it varies depending on the number. Ethylene itself has the relatively lowest epoxidation rate, with propylene and other alpha-olefins the next slowest. Compounds (indicating substituents) can be epoxidized very quickly. Thus, as the number of substituents on the double-bonded carbon increases, it becomes easier to epoxidize the bonding moiety.

The production of ethylene oxide from ethylene has long been carried out by reaction with molecular oxygen over a silver catalyst. Numerous patents have been granted for various flask contact processes for the production of ethylene oxide. Unfortunately, the silver catalyst process has not been commercialized for olefins other than ethylene. For a long time, commercial production of propylene oxide could only be carried out via the complicated chlorhydrin process.

Other commercial methods for producing substituted oxides from alpha-olefins such as propylene are described by John olla
It was not discovered until the work of R. R. in the 1960s. In his US Patent Section 3.351°635, molybdenum, tungsten, titanium, columbium,
It has been taught that organic oxide compounds can be prepared by reacting olefinically unsaturated compounds with organic hydroperoxides in the presence of tantalum, rhenium, selenium, chromium, zirconium, tellurium or uranium catalysts. Kollar U.S. Patent Section 3
, 350,422 teaches a similar process using a soluble vanadium catalyst.

However, although Kollar's work is recognized as being extremely important in the development of a commercial propylene oxide process that does not rely on the chlorohydrin process, Kollar
It has been observed that the catalytic method of lar catalysis (in which molybdenum is the preferred catalyst) has a number of problems, including the production of large amounts of alcohol corresponding to the peroxides used. Using t-butyl hydroperoxide as a coreactant produces substantially equimolar amounts of olefin epoxide and 1-butyl alcohol. Another problem is that olefin oligomers are produced as by-products. When propylene is the olefin to be epoxidized, various propylene dimers and in some cases so-called hexenes are usually formed. Besides being undesirable in that it is not the desired use of propylene, it also creates problems in separating the desired propylene oxide from the product mixture. Additionally, molybdenum catalysts are not stable or have low catalyst recovery rates for recycling.

Various methods have been investigated in an attempt to improve molybdenum catalyzed epoxidation of propylene.

One method has attempted to improve the catalyst itself. Patents covering the production of various molybdenum epoxidation catalysts include US Pat.
．． No. 362.972 is mentioned.

a molybdenum compound in which molybdenum has a valence of +6;
Alternatively, the vanadium compound has a valence of +5 and has at least 4 carbon atoms per carboxyl group. Hydrocarbon soluble salts of molybdenum or vanadium can be prepared by heating with carboxylic acids having 4 to 50 carbon atoms. Beck
In U.S. Pat. There is.

Olefin epoxidation catalysts can be prepared by reacting molybdenum trioxide with monohydric saturated alcohols having 4 to 22 carbon atoms, or mono- or polyalkylene glycol monoalkyl ethers, or mixtures thereof. , U.S. Pat. No. 3,480,563 to Bonetti et al. These catalysts contain only 0.07-0.93% molybdenum, making the molybdenum content too low and undesirable for commercial use. Bonetti et al. , did not realize that the ratio of alcohol to molybdenum compound reactant was important to provide a soluble active epoxidation catalyst. They also do not show any advantage of adding ammonium hydroxide to the preparation, nor the important factors found when molybdenum trioxide is reacted with 2-ethyl-1-hexanol.

In U.S. Pat. Hydroperoxide, peroxide or H*Om
It has been discovered that a molybdenum catalyst can be produced by reacting with Molybdenum compounds prepared by reacting ammonium-containing molybdic acid with hydroxy compounds, such as organic primary or secondary alcohols, glycols or phenols, (:a
No. 3,784,482 and 3,787,329 to Vitt.

Additionally, the U.S. patent issued to Sorgenti 3.5
No. 73.226, molybdenum powder is mixed with a mixed stream containing unreacted tert-butyl hydroperoxide and a polyhydric compound with a molecular weight of 200 to 300 and 4 to 6 hydroxyl groups per molecule. It is disclosed that a molybdenum-containing epoxidation catalyst solution can be prepared by heating. These catalysts are described in U.S. Patent No. 3.6 to Sorgrunti.
No. 66.777 for the epoxidation of propylene.

U.S. Patent No. 3,953°36 to Lines et al.
No. 2 discloses that a novel molybdenum epoxidation catalyst can be prepared by reacting an oxygen-containing molybdenum compound with hydrogen peroxide and amines, and optionally water or alkylene glycol at elevated temperatures. has been done. Similar catalysts are prepared by reacting oxygen-containing molybdenum compounds with amines and alkylene glycols at elevated temperatures according to U.S. Pat. No. 4,009,122 to Lines et al.

The US patent to Mattucci et al. also relates to a molybdenum glycol catalyst made from molybdenum acetylacetonate and isolated as a solid. Molybdenum derivative compounds also useful as epoxidation catalysts, which must be used in solution with a hydrocarbon solvent when the materials are used as epoxidation catalysts, are disclosed in U.S. Pat.
1.090, oxygen-containing molybdenum compounds such as molybdenum acetylacetonate, molybdic acids, and molybdenum oxides, and vicina
1) with an organic compound having a hydroxyl group in the presence of a hydrohalic acid such as hydrofluoric acid or hydrochloric acid.

[Synthesis of molybdenum/alkylene glycol complexes useful as epoxidation catalysts]
of Mo1ibdenun+/Alkylene
Glycol Comp'1exes Useful a
s Epoxidation Catalysts l
Marqui dated December 2, 1986 entitled J.
U.S. Pat. ammonia-containing molybdenum compound in a ratio of 7 to 20 moles of alkylene glycol per gram of molybdenum atoms in the presence of a small amount of water.
catalytically active by heating to 130° C. and then stripping the reaction product under mild conditions to finally provide a molybdenum complex with a water content of about 0.5-6% by weight. A method of making a molybdenum complex is disclosed.

“Synthesis of Molybdenum Oxide/Alkanol Complex” filed by Marquis et al. on December 6, 1985 and currently under examination.
bdenum Oxide/Alkanol Comp
U.S. Patent Application No. 06/2006 entitled lexes)
No. 804.132 discloses the trioxidation of 06-CI3 alkanols, such as 2-ethyl-1-hexanol, by a process initiated in the presence of aqueous ammonium hydroxide and carried out at 120°C to 190°C for 3 to 8 hours. A method is disclosed for reacting molybdenum oxides, such as molybdenum, with substantially complete removal of the ammonia and water generated to obtain a liquid reaction product of a molybdenum/alkanol complex dissolved in unreacted alkanol.

Marquis et al. filed on December 6, 1985.
Synthesis of ammonium molybdate/alkanol complex
mMolybdate/Alkanol Complete
U.S. Patent Application No. 06/804 entitled xes ) J
．． No. 131, a controlled amount of a C8-C+s alkanol, such as 2-ethyl-1-hexanol, and ammonium molybdates, such as ammonium heptamolybdate tetrahydrate, in the presence of water at atmospheric pressure, 120-190
℃ temperature for 3 to 8 hours to substantially completely remove the ammonia and water generated, the water content is less than 0.1% by weight, and the molybdenum/alkanol dissolved in the unreacted alkanol. The present invention relates to a method for obtaining a liquid reaction product consisting of a complex.

There remains a need for epoxidation catalysts that are stable, easy to manufacture, and have high molybdenum content.

Light history 11! The present invention relates to an improved method for producing molybdenum complexes by reacting ammonium-containing molybdenum compounds and alkylene glycols under reduced pressure at temperatures ranging from ambient temperature (e.g., 25°C) to about 150°C or less. .

In US Pat. No. 4,626,956 to Marquis et al., the ratio of alkylene glycol reactant to molybdenum compound is determined by the ease of filtration of the product reaction mixture,
and an improved process for making molybdenum/alkylene glycol complexes based in part on the discovery that the stability of the resulting complex solution remains clear and free of solids for extended periods of time is disclosed. ing. It has also been found that the actual origin of the molybdenum complex preparation is extremely important in determining whether the resulting complex is good or bad for ultimate use as an epoxidation catalyst. Furthermore, when using a molybdenum complex produced from EG (ethylene glycol) or PG (propylene glycol) as an epoxidation catalyst, if the reaction temperature is too high, the molybdenum content in the complex will be low and the solid content will be large. formed, so it is too high (165-1
80°C), and in order for the complex to be useful as an epoxidation catalyst, a high molybdenum content can be achieved by adjusting the ratio of glycol to gram atoms of molybdenum, without distilling off the glycol. If the molybdenum content of the complex is increased by glycolic distillation, the water content of the complex will be too low and the selectivity based on the organic hydroperoxide consumed will be low, leading to a reduction in epoxidation. The effect as a catalyst becomes poor.

The preferred method of U.S. Pat. No. 4,626,956 is to set the ratio of moles of glycur to gram atoms of molybdenum in the range of 8:1 to 16:1, and
Next, vacuum stripping is carried out so that the bottom residue is 80-95% by weight of the charge, water, Removes ammonia etc.

According to the present invention, ammonium dimolybdate and an excess amount of ethylene glycol are mixed in a reaction vessel under atmospheric conditions of temperature and pressure, and then the pressure in the reaction vessel is simultaneously reduced to about 50%. The pressure is reduced to ~150 amHg, and the reaction is heated under stirring to an ambient temperature (e.g., 25° C.) to approximately 150° C. over a period of approximately 5 to approximately 60 minutes, while simultaneously removing generated reaction byproducts. Returning the mixture to ambient temperature and pressure results in a dissolved molybdenum content of about 10
~15% molybdenum by weight and about 0.5% to about 5% water
By a laminar flow vacuum manufacturing process comprising steps of recovering a substantially clear reaction product consisting of a solution of a molybdenum/ethylene glycol complex in unreacted ethylene glycol containing % by weight, the Marquis et al. It has been found that a molybdenum/ethylene glycol complex substantially identical to that of No. 4,626,596 can be rapidly and effectively produced. Preferably, the mixture is heated to a pressure of about 10 to about 80 mm Hg under the pressure of 25-1
Heat to 20°C for about 10-50 minutes and hold at this temperature for about 4-25 minutes. More preferably, the mixture is about 1
Under pressure of 5-60 mmHg, at 25-100°C, 15-
Heat for 40 minutes and hold at this temperature for about 6-20 minutes.

The molybdenum starting material according to the invention is ammonium dimolybdate.

Ethylene glycol is another co-reactant used to make the molybdenum complexes of the present invention.

The ratio of glycol to gram atoms of molybdenum (moles of ethylene glycol) in ammonium dimolybdate is important in determining the amount of molybdenum present in the final complex and the ease of processing.

For the ethylene glycol/ammonium dimolybdate system of the present invention, the preferred ratio of reactants is 7=1 expressed in moles of ethylene glycol to gram atoms of molybdenum in the ammonium dimolybdate compound.
~20:l.

A particularly preferred ratio of moles of glycol to gram atoms of molybdenum is from 9:1 to 11:1. In order to obtain the best complex in terms of molybdenum content, ease of processing and storage stability, the proportion of water remaining in the complex should be in the range 0.5-5% by weight. The reaction temperature for producing the inventive complexes should be between about 25 and 150°C, preferably between 25 and 120°C, with a final pressure of about 5 to about 100 mmHg, more preferably at reduced pressure of about 10 to about 80 mmHg. Must.

The pressure of the reaction mixture must be reduced at the same time as the reaction mixture is heated to the desired final temperature; this step takes about 5
It has been found that there is no need to increase the holding time of the reaction mixture at the final temperature, which should be carried out for ~60 minutes, more preferably from about 5 to about 60 minutes, and holding times of 7 to 13 minutes are suitable. (see Examples 1.2 and 3)
.

In general, for the best complexes of the present invention, filtration is not necessary; sufficient overhead is removed during the reaction such that the amount of complex in the bottoms is about 85-95% by weight of the charge; The water content of the catalyst is preferably between 0.5 and 5.
．． It is in the range of 0% by weight. Particularly in epoxidation applications, the water content of the final complex should generally be between about 1 and 3% by weight.

The reaction mixture obtained by the method described above is a clear, substantially solids-free solution of molybdenum/ethylene glycol complex in unreacted ethylene glycol and can be recovered and used without filtration. . The solution has a dissolved molybdenum content of about 10 to about 1
5% by weight and a water content of 0.5-5.0% by weight,
It is a storage-stable and catalytically active substance. When prepared by the preferred method of operation, the solution typically contains about 11-14% by weight molybdenum, about 1-3% by weight water, and constitutes about 90-92% by weight of the total weight of the filler material.

Since the molybdenum/ethylene glycol complex of the present invention is titrated as an acid despite having no additional free acidic groups such as carboxylic acid groups, its use as an acid catalyst component is likely to be similar. For example, this complex can be used as a useful cyclization catalyst to dissociate water, such as in the production of tetrahydrofuran from 1,4-butanediol and triethylenediamine from hydroxyethylpiperazine. The complex of the invention relates to hydroxylations such as the production of resorcinol from toluene in the presence of hydroperoxides, carbonate formation from olefins, carbon dioxide and hydroperoxides, and from hydrocarbons and organic hydroperoxides. It can be used as a catalyst for the production of oxygenates. Other catalyst applications for these complexes, in addition to those mentioned above, include condensation, dehydration, esterification, oligopolymerization, polymerization, disproportionation, and rearrangement. Molybdenum/glycol complexes can also be tried as corrosion inhibitors in antifreeze formulations and as direct additives to oils, greases and other lubricating fluids.

The molybdenum/ethylene glycol solutions of the present invention are highly suitable for use as epoxidation catalysts. Before adding the epoxidation reaction mixture, the complex catalyst solution is typically mixed with t-butyl alcohol (TBA) of one of the reactants, usually t-butyl hydroperoxide (TBHP).
Premix with hydroperoxide like solution.

It is well known that solubilized molybdenum complexes effectively catalyze the epoxidation of propylene to propylene oxide in the presence of t-butyl hydroperoxide.The alkylene glycol/molybdenum complexes of the present invention surprisingly In such a reaction, at a TBHP conversion of about 98-98.4%, 98%
It provides selectivity to propylene oxide on the order of ~99% while minimizing propylene dimer formation and extremely low methyl formate formation.

Epoxidation is usually carried out by reacting an olefin with an organic hydroperoxide in the presence of a catalyst and a solvent. Preferably the olefin is propylene and the hydroperoxide is TBHP. With these reactants, the desired products are propylene oxide (PO) and t-butyl alcohol.

The concentration of catalyst is preferably between 200 and 600 ppn based on the sum of olefin and organic hydroperoxide.
It is +. Furthermore, the reaction should be carried out at a temperature in the range from 50 to 180°C, preferably from 90 to 140°C, particularly preferably from about 100 to 130°C. This reaction temperature is
relatively low compared to other commercial methods. Another unusual feature is that the preferred molar ratio of olefin to hydroperoxide is very low, about 0.9:1 to 3
．． It is of the order of 0:l.

Another preferred embodiment of the epoxidation consists in carrying out the reaction in a two-stage reaction in which the reaction times are approximately equal and the first stage is carried out at a lower temperature than the second stage6, for example during the first hour of the reaction. Preferably carried out at a temperature in the range of 50 to 120°C, with the second and final hour reaction at a temperature of about 120 to 120°C.
Perform at 150°C.

The invention will be further illustrated by the following examples, which are given for illustrative purposes and are not intended to limit the scope of the invention.

EG 1 in a 500 ml round bottom flask equipped with a magnetic cooler, thermometer, K-head and condenser.
91.6 g (3,0903 mol) and 58.4 g ammonium dimolybdate (ADM, molybdenum 0.34
35 grams atom) was added. The ratio of the number of moles of EG to the number of gram atoms of molybdenum was 9/1. The stirrer was started, and vacuum suction was performed at the same time as heating started. Heating was started at 9:15 (25° C.) with a reduced pressure of 30 mn+Hg. At 9:27 (12 minutes later) the temperature was 100.
The reaction mixture was pale yellow in color and had a slight solid content. Heating at 100°C was continued for 8 hours until the reactants were clear and free of solids.
The vacuum lasted for more than 25 minutes (the degree of vacuum was 25 m from 40 mmHg).
The reaction mixture was clear and free of solids even after cooling. Catalyst preparation took only 20 minutes in total from heating to completion of the reaction. The weight of the top product in the flask is ts, 5g (
moisture (35.5%) and the weight of the cold trap is 1.4g.
(moisture 87.5%), the weight of the product was 227.
The product was 2g (90.88% of loading).
Molybdenum 14.0% (measured by atomic absorption method), water 2
．． 27% (measured by Karl Ficher), N.

1.10% (measured by Kjeldahl) and had an acid value of 168.17 mg KOH per sample Ig.

In a flask equipped with each apparatus as described in Example 1,
EG196.2g (3,16452 mol) and ADM
53.8 g (0.3165 gram atom of molybdenum) was added. The ratio of the number of moles of EG to the number of gram atoms of molybdenum was 10.0/l. The cooler was started and heating and depressurization started at the same time. When heating was started at 7:55 am (temperature 23 °C), the reaction mixture reached 100 °C in just 10 minutes (degree of vacuum 40 mmHg), and the reaction mixture was pale yellow and contained some solid content. Ta. If heating continues for another 13 minutes at 100℃, the degree of pressure reduction will be 40mmHg.
to 25 mmHg, and the reaction mixture became clear and free of solids.

Catalyst preparation took only 23 minutes total from start of heating to cooling. The weight of the overhead material was 15.7 g (37.9% moisture), the weight of the cold trap was 1.6 g
(moisture 89.83%), the weight of the product was 228
．． 1 g (91.24% of loading), the product contained 13.2% molybdenum, 1.06% water and 13.1% N
6%, and had an acid value of 159.24 mg KOH per gram of sample.

In a flask equipped with each apparatus as described in Example 1,
EG 200.1g (3,2274 mol) and AD
49.9 g of M (0.2935 gram atom of molybdenum) was added. EG for the number of grams of molybdenum atoms
The molar ratio of was 11.0/1. The stirrer was started and heating and pressure reduction started at 10:40 am (24°C). At 10:53 a.m., the reaction mixture reached 100°C (degree of vacuum: 35 mm + Hg) (13 minutes had passed since the start of heating).
(g to 30+n+sHg and held at 100°C for an additional 7 minutes. At this point, the reaction mixture was cooled and
It was confirmed that no solid content was present. The total heating and reaction time was 20 minutes. The weight of the overhead was 14.9 g (37.68% moisture), the weight of the cold trap was 1.2 g (87.47% moisture).

The weight of the product was 229.7g. The product contains 11.8% molybdenum (measured by atomic absorption spectrometry) and 2.8% water.
1% and 3.09% Na, 140 per gram of sample.
．． It had an acid value of 65 mg KOH.

191.6 g (3,0903 moles) of EG and 58.4 g ammonium dimolybdate (AD
M, 0.3435 gram atom of molybdenum) was added. The ratio of the number of moles of EG to the number of gram atoms of molybdenum is 9
/l. At 8:00 AM, the reactants were added to the flask and heating was started. It was filled with nitrogen under atmospheric pressure. At 8:20 am the reaction mixture reached 100°C and the color was milky white (20 minutes had passed) 6. The reaction mixture was heated to 100°C.
(The solid content remained until 9:20 a.m.) and cooled to 60 °C for 10:35 a.m.) At this point, vacuum suction was performed (35 + u + Hg) at 100 °C.
The reaction mixture reached 100°C at 10:47 a.m. (45 mn+Hg) and the reaction mixture was heated under reduced pressure (45+a+wHg) for an additional 8 minutes (10:47 a.m.).
The temperature was maintained at 100°C for up to 5 minutes.

At this point, the catalyst preparation was cooled and found to be clear and free of solids. It took 2 hours and 55 minutes (175 minutes) from initial heating to cooling of the preparation. The weight of the overhead product was 9.5 g (49.85% moisture), the weight of the cold trap was 1.0 g (92.42% moisture),
The weight of the product is 234.7g (93.88% of the filling amount)
), analysis of the product revealed that molybdenum was 13.5
%, N, 1.21%, water 2.32%, sample 1
It was confirmed that the acid value was 164.91 mg KOH per gram.

In a flask equipped with each apparatus as described in Example 4,
EG 196.2g (3,164 mol) and ADM
53.80 g (0.3165 gram atom of molybdenum) was added. EG for the number of grams of molybdenum atoms
The molar ratio of was 10/1. At 10:55 a.m., the reactants were added to the flask and heating started (at atmospheric pressure,
nitrogen filling), and the reaction mixture was heated to 100°C at 11:00 am.
(15 minutes elapsed until reaching 1.0), heating at 100℃
(until 12:10 p.m.) and then rapidly cooled to 85°C for 5 minutes (total elapsed time was 1 hour 20 minutes).The reaction mixture was then cooled under reduced pressure (45 mmHg
), the temperature reaches 100℃ in just 10 minutes (30mmHg), and then further heated under reduced pressure (30mmHg).
) for 10 minutes at 100°C and then cooled. No solids were present. Final cooling began at 12:35 p.m. The manufacturing process required 1 hour and 40 minutes (100 minutes) from the start of heating to cooling. The weight of the top of the tower is 13.
6g (49.39% moisture), the weight of the cold trap was 1.9g (92.96% moisture), the weight of the product was 229.9g (91.96% of the filling amount) , analysis of the product revealed that molybdenum 13.2%, Na1
．． 07%, water 1.54%, 156 per gram of sample
．． It was confirmed that it had an acid value of 81 mgKOH.

Mormo 1 puden gram = 11
1, =118 5990
A flask equipped with the apparatus as described in Example 4 was charged with 200.12 g (3,228 moles) of EG and A
49.88 g of DM (0.3074 gram atom of molybdenum) was added. The molar ratio of EG to the number of gram atoms of molybdenum was 11.0/1. At 7:35 a.m., the reactants were added to the flask and heating started (23°C,
The reaction mixture reached 100 °C at 7:55 a.m. (20 min elapsed), held at 100 °C for 1.0 h at 8:55 a.m.), then quickly increased to 65 °C. Cooled down (took 15 minutes and the time was 9:10am)
, a reduced pressure (35 mmHg) was applied at 65°C, and heating was started (at 9:00 am), the reaction mixture reached 100°C after about 13 minutes (9:23 am), and the degree of vacuum was 25 a.
The reaction mixture, which had reached +mHg, was heated to 100°C (25+u+
Hg) for another 10 minutes and observed (9:30am).
3 minutes), no solids were observed to be present and finally cooled. Total manufacturing time from initial heating to cooling is 1
The time was 58 minutes (118 minutes), and the weight of the top product was 14
．． 3 g (40.50% moisture), the weight of the cold trap was 1.9 g (91.93% moisture), the weight of the product was 229.2 g (91.68% of the filling amount),
Analysis of this shows that molybdenum is 11.9% (analyzed by atomic absorption spectrometry, theoretical value = 12.29%), N, 0.9
2%, water 1.24%, 143.4 per gram of sample
It was confirmed that it had an acid value of 4 mgKOH.

Claims (1)

Claims: 1. (a) a substantially diluted compound in a quantitative ratio such that the ratio of moles of ethylene glycol to gram atoms of molybdenum ranges from about 7:1 to about 20:1; ethylene glycol and substantially undiluted ammonium dimolybdate are mixed under atmospheric conditions in a reaction vessel; (b) the mixture is stirred while removing volatile reaction by-products; , for about 5 to about 60 minutes, simultaneously increasing the pressure to about 5
~25℃~about 1 while decreasing to about 100mmHg
(c) the reaction mixture is then returned to ambient conditions to form a substantially solids-free, catalytically active material having a molybdenum content of about 10 to about 15% by weight. , a process for producing catalytically active molybdenum complexes, characterized in that a solution of the molybdenum/ethylene glycol complex in unreacted ethylene glycol is recovered. 2. The ratio of the number of moles of ethylene glycol to the number of gram atoms of molybdenum in the reaction starting mixture is about 9 to 11.
and the reaction mixture is heated to a temperature of about 100° C. for a period of about 15 to about 40 minutes while simultaneously reducing the pressure to about 15 to 60 mm Hg; 3. The process of claim 1, wherein the overhead from which reaction products generated are removed constitutes about 8 to about 10% by weight of the feed mixture, and the final product contains about 11 to about 14% by weight of molybdenum. , (a) substantially undiluted ethylene glycol in a quantitative ratio such that the ratio of moles of ethylene glycol to gram atoms of molybdenum ranges from about 7:1 to about 20:1. (b) preparing a raw material mixture by mixing undiluted ammonium dimolybdate in a reaction vessel at a temperature of about 20 to about 30° C. and under atmospheric pressure; at about 25° C. while simultaneously reducing the pressure to about 10 to about 80 mmHg for about 10 to about 50 minutes under stirring while removing byproducts.
(c) heating the mixture to a temperature of from about 150°C to about 150°C; (d) the reaction mixture is then returned to the starting temperature and pressure; (e) the molybdenum-containing recovering a substantially solids-free, catalytically active, solution of a molybdenum/ethylene glycol complex in unreacted ethylene glycol having an amount of about 10 to about 15% by weight; , such recovery complex comprising about 88% to about 95% by weight of the feed mixture, and about 1% to about 3% water;
A method for producing a catalytically active molybdenum complex, characterized in that it contains % by weight. 4. In step (a), the ratio of the number of moles of ethylene glycol to the number of gram atoms of molybdenum is about 9 to about 11.
in step (b), heating the raw material mixture to a temperature of about 25°C to about 120°C for about 10 to about 50 minutes while simultaneously reducing the pressure to about 10 to about 88 mmHg; and step (c) ), the mixture is held at the temperature and pressure set in step (b) for about 4 to about 25 minutes, and the complex recovered in step (e) contains about 88% of the raw material.
4. The method of claim 3 comprising up to about 95% by weight. 5. In step (a), the ratio of the number of moles of ethylene glycol to the number of gram atoms of molybdenum is about 9 to about 11.
In step (b), the raw material mixture is heated to a temperature of about 25°C to about 100°C for about 10 to about 50 minutes while simultaneously reducing the pressure to about 15 to about 60 mmHg, and step (c) ), the mixture is held at the temperature and pressure set in step (b) for about 6 to about 20 minutes, and the complex recovered in step (e) contains about 90% of the raw material.
4. The method of claim 3 comprising from about 11 to about 14 weight percent molybdenum.