JPS6029689B2 - Method for producing alkynols using ethynylation catalyst and low pressure reaction - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for producing alkynols by a low pressure aethynylation reaction, ie a process for introducing acetylene into a reaction mixture of aldehytes to produce products containing triple bonds.

Alkynols include, for example, U.S. Pat.
No. 60, No. 2768215, No. 3108140, No. 329489 and No. 3560576, i.e., aldehytes or ketones are prepared with the general formula R-C...CH, where R is hydrogen or carbide. hydrogen (e.g. methyl, vinyl or phenyl)
It is generally produced by reacting with an acetylenic hydrocarbon.

The acetylene or acetylenic hydrocarbon is introduced as a gas during the reaction, while the aldehyde or ketone is liquid under the reaction conditions or is present in a liquid solvent or diluent. The reaction is carried out under pressure for 50 to 15,000
It is known that the process progresses at mild temperatures.

Generally 2 to 3 pressures are taught. However, experience has shown that suitable pressures for the compressed acetylene gas are in the range of 1 p atm or less, with careful control of temperature. Even at these pressures, the acetylene gas is diluted with an inert gas or vapor, such as nitrogen, hydrogen, or carbon dioxide, to reduce the risk of severe decomposition. However, these high pressure reactions still have inherent safety limitations. The ethynylation reactions described above generally employ some form of cuprous acetylide catalyst, which can be generated or activated from a variety of copper compounds. These ethynylation reactions are carried out using supported or unsupported catalysts. These cuprous acetylide catalysts have been conventionally made by various methods and subsequently used to contact acetynylation reactions, a typical reaction being the reaction of formaldehyde and acetylene in the presence of a cuprous acetylide catalyst. There is a reaction that produces butynediol.

These conventional catalysts exploded easily on their own, were difficult to filter, and were overly active, resulting in undesirable catalysis of cuprene formation.

They are often used with bismuth in high pressure systems to minimize cuprene formation. Supported catalysts are also used in the above-mentioned high-pressure systems, for example impregnated with a solution of copper nitrate and bismuth, dried and calcined to form metal oxides, and then the copper oxides are converted to acetylides in situ during the ethynylation reaction. It converts. However, these reactions suffer from the major drawback that butynediol is not generated at a sufficiently fast rate and its yield per gram of catalyst is also relatively low. In order to achieve favorable economic conditions for optimizing the reaction due to low ethynylation operating costs, the use of a supported catalyst in the form of pellets in a fixed bed plug flow process, the feeding of dilute aqueous formaldehyde, and the comparison Multiple point injections of acetylene at extremely high pressures are selectively used to exhaust excess formaldehyde and to minimize the degree of distillation required to produce product of the required purity.

However, an undesirable feature of this method is not only the normal acetylene operating pressure of up to 26 atmospheres, but also the high pressures of up to two parts above normal pressure associated with the excessive acetylene decomposition that occurs at high pressures. There is a need to design the reactor to withstand the initial investment. It has also been proposed to use supported catalysts such as slurries during continuous ocean-going reactions.

However, it has been found that such processes not only require removal and purification of the catalyst at often short intervals to avoid contamination, but even with continuous and complete catalyst purification and circulation. It was necessary to operate at relatively low formaldehyde conversions and relatively high acetylene pressures even to finally break even and achieve acceptable space/time yields. Previously, it was not possible to simultaneously produce a supported catalyst and produce butyne diol using an economical low-pressure method (5<em>Ab
struct252, 1963 and 44Khim. P
rom. No. 12,885-87, 1968). When using such low pressure methods, the yield and purity of the product was not sufficient to warrant the economical use of such methods. Traditionally, such processes have been more expensive to operate than fixed-bed, full-flow processes due to higher product separation costs, and have had few cost savings due to relatively slow reaction rates and poor catalyst life. Active acetylide catalysts made from cuprous compounds, which are generally made from cuprous compounds or by methods that reduce almost all of the cupric compounds to cuprous before acetylide formation, have low carbon-to-copper ratios. Under these conditions they are usually found to be in the form of small sticky and relatively explosive particles containing significant amounts of metallic copper;
It has also been reported.

Additionally, the literature describes Daiichi Steel acetylide catalysts made from cupric compounds under acetylene partial pressures greater than 2 atmospheres or in the absence of formaldehyde, or in the presence of large imbalances of acetylene or formaldehyde, or in which copper is dissolved. Cuprous acetylide catalysts made from highly soluble or dispersed cupric media tend to have insufficient total surface area and are therefore not very effective for the production of alkynols. is claimed. The present invention provides clear refutation of these theories. To overcome the above-mentioned difficulties, catalysts based on carbonated steel or certain insoluble copper compounds are disclosed in US Pat. No. 35,605.
It is described in the specification of No. 76.

However, such catalysts have shown to be very sensitive and permanently lose their activity when formaldehyde or acetylene is depleted, and as pointed out therein, they easily explode when heated to 162↑0. In contrast, the catalyst of the present invention is not permanently damaged by said deficiency and furthermore cannot explode under any circumstances. It is an object of the present invention to provide a low pressure ethynylation catalyst bridger and an active catalyst derived therefrom.

Another object of the present invention is to provide a method for producing acetylenic diols using the above-mentioned active catalyst.

Another object of the invention is to overcome one or more disadvantages of the prior art.

Generally speaking, ethynylation catalysts consist of water-insoluble cuprous acetylide containing both copper and magnesium silicate.

The present invention further provides for the simultaneous action of acetylene and formaldehyde at a partial pressure of less than 2 atmospheres, preferably from about 70 to about 1200
A method is provided for generating an active catalyst by subjecting the catalyst to a catalytic converter in an aqueous medium at a temperature of zero.

Furthermore, the present invention provides a batch or continuous process for carrying out the acetynylation process, the latter method comprising simultaneously and continuously combining the carbonyl compound and acetylene with the above-mentioned catalyst as a slurry in an aqueous medium and under the above-mentioned pressure. It is preferable to bring the mixture into contact with the above temperature to carry out a continuous fly-azusa reaction.

Both catalyst generation and alkynol synthesis can proceed continuously and simultaneously. However, it is alternatively possible to first generate the catalyst in a separate reaction zone and then introduce the catalyst into the ethynylation reaction zone to carry out the latter reaction. Yet another method is to use the generated catalyst (according to any generation method) until its activity drops below a desired point, at which time the catalyst is removed completely or a portion of it is removed (this can be done continuously). At the same time, unregenerated or separately generated fresh catalyst can be added to the reaction medium to maintain the activity level. In either case, the simultaneous method described above operates along the following lines.

The reduction of the cupric compound and the consequent production of the alkynol may be carried out in the same reactor, thus providing continuous and simultaneous generation of the catalyst and the alkynol product at any time.

The synthesis is carried out with the catalyst generated under atmospheric pressure in an inert powder carrier, ie magnesium silicate, and is thus completely safe since explosion of the catalyst is avoided by the inert carrier.

The carrier can be made from magnesium silicate having a bulk density of about 0.2 to 1.0 g/m in powder form and impregnated with a solution of copper salts (if desired with the addition of bismuth compounds). Good, this acts as a polymerization inhibitor of acetylene by copper metal). The mixture is heated to drive off the volatile components and convert the salt to the cupric precursor of the active catalyst. The catalyst thus obtained is passed through a ring (American Standard Node) having 10 to 300 holes per length lin. Repeated tests have shown that the copper-impregnated magnesium silicate powder of the present invention, unlike most prior art steel-containing catalysts, cannot explode or burn.

Without wishing to be bound by any theory, it is believed that some type of chemical interaction occurs between the copper and the magnesium silicate carrier lattice.

Repeated water washings showed that no copper was washed out of the impregnated carriers, whereas pumice and diatom carriers were impregnated followed by water washings to remove all the copper. The chemical interactions described above therefore have the advantage that the catalyst of the invention, in contrast to the prior art catalysts, does not decompose acetylene spontaneously and does not give rise to catalytic detonation, as well as the fact that it does so at low acetylene pressures. It is believed that this is responsible for the fact that the process has activity that allows it to proceed at an economical rate. This interaction is also believed to be responsible for the long lifetime of the catalyst. Typical catalysts of the present invention contain from about 5 to about 20% copper, preferably from about 10 to about 15%, based on the total weight of the catalyst including its carrier.

The copper is present in the form of metallic steel and cuprous acetylide, the main part of which is cuprous acetylide. Up to 3% bismuth, preferably 2-28%, may also be present. Copper can be determined, for example, by decomposing the catalyst with concentrated HCI and analyzing the solution formed using standard quantitative analytical methods. Typically, the unregenerated catalyst is about 5 to 1
Contains 5% copper. The percentage of copper in use tends to rise as the magnesium silicate carrier partially dissolves, exposing new catalyst surface. The catalyst of the invention is preferably generated by introducing acetylene into the formaldehyde-catalyzed reaction medium. As mentioned above, when generating a catalyst, the second steel bricursor is about 60~
The reaction components are subjected to simultaneous action in situ in a substantially homogeneous medium at a temperature of 12,000 °C and under the required pressure. Temperatures outside this range, or in strongly basic or acidic media, or at acetylene partial pressures greater than 2 atmospheres, or in the substantial absence of either formaldehyde or acetylene, tend to result in a less effective catalyst. has. The preferred catalyst generation temperature is in the range of 60-1200C. The pll of the aqueous medium is 3-10, preferably 5-6.
The concentration of formaldehyde in the aqueous medium is usually from 5 to 6% by weight at the beginning of the reaction, advantageously at least 1% by weight, preferably from 30 to 4% by weight. Usually, the partial pressure of acetylene on an aqueous medium is 0.1 to 1.9 atm, and 0.4 to 1.9 atm.
5 atmospheres is preferred. In carrying out the catalytic generation, nitrogen or other substantially inert gases such as methane or carbon dioxide may be present, as well as common constituents of crude acetylene such as methylacetylene and ethylene.

Preferably, oxygen is removed for safety reasons. 4. In the batch catalyst system, the supported cupric precursor is slurried in a cold neutral formamide solution and acetylene is introduced while the slurry is heated.

Similar results can be obtained by heating the formaldehyde and catalyst slurry to a not too high temperature, e.g. 70°C, before introducing the acetylene. In the case of a large batch system, it is preferable to gradually introduce the thermoneutral formaldehyde W or cupric precursor under acetylene pressure. Advantageously, the aqueous solution is a stream containing propargyl alcohol and/or butine diol, for example a circulating stream. The catalytic generation reaction is preferably continued until the cupric is substantially converted to the cuprous form, which when using the preferred cupric precursor, all precursors are contacted under the conditions described above. It takes 4 to 4 temples to reach the back.

It is also preferred that the temperature, pH and acetylene/formaldehyde concentration balance and ranges described above be maintained during catalyst generation. However, during the production reaction, deviations from the conditions described above may be tolerated when the reaction is relatively insensitive to small changes in operating conditions. The pH of the aqueous medium is
As the reaction progresses, the rate and extent of this decline tend to increase depending on the initial acidity of the reaction medium and the reaction temperature.

Therefore, pH can be advantageously controlled to some extent by starting at a preferred initial pH of 3-10 and operating in a preferred temperature range of 60-120 qo. Further control may be achieved by adding small amounts of an acid acceptor such as sodium acetate as the reaction progresses. Further control is achieved by continuously introducing new neutral formaldehyde solution into the stirring reaction zone as the reaction progresses (if desired, the acidic effluent can be separated from the copper-containing particles), This can be achieved by generating a catalyst as a reaction. All of this is done while maintaining the acetylene partial pressure. The ethynylation reaction itself is 80-120q
contacting the reactants with an aqueous slurry of catalyst at a partial pressure of not more than about 1.9 atmospheres. Formaldehyde and acetylene are preferably introduced continuously into the reaction zone, where they are introduced into the aqueous catalyst slurry, preferably below its surface, and thoroughly incorporated into the catalyst slurry by vigorous mixing. The effluent is then removed continuously. The reaction temperature for ethynylation is 60-120
qo is desirable, 80-11yo is advantageous, 85-11yo is advantageous;
110°C is preferred. The pH of the reaction mixture is desirably between 3 and 10, preferably between 4.5 and 7, and may be maintained at pH' by ion exchange or acid acceptor treatment of the continuous feed. During the ethynylation reaction, the formaldehyde concentration in the liquid in contact with the slurried catalyst is usually between 0.5 and 60%, advantageously between 0.5 and 37% at steady state.

The acetylene partial pressure is usually at least 0.5 atmospheres. Advantageously the acetylene partial pressure is between 0.4 and 1.9 atmospheres, preferably the acetylene partial pressure on the aqueous medium is between 0.5 and 1.5
It is atmospheric pressure. The catalyst is about 1 part by weight per 10 parts by weight of the aqueous medium.
Present in an amount of ~2 parts by weight. For purposes of the present invention, in the absence of substantially extraneous gases, the acetylene partial pressure is preferably taken as the absolute pressure of water and formaldehyde at the reaction temperature subtracted from the total pressure. Crude acetylene can be used as in catalyst generation, but to be safe it should be substantially oxygen-free.
The effluent from the reaction zone is heated and/or vacuum treated to volatilize the formaldehyde, propargyl alcohol and some of the water, which are condensed and combined with additional concentrated formaldehyde for circulation to the ethynylation reactor; In continuous operation, the accumulated methanol can be blown off at convenient intervals and the remainder of the effluent can be sent directly to hydrogenation as aqueous alkynol.

Alternatively, the effluent from the reaction zone may be fed to a conventional plug flow ethynylation for reaction with excess formaldehyde. The present invention will be further explained below with reference to Examples, but these are for illustrative purposes and not for limiting the present invention.

Parts and proportions in the examples are by weight unless otherwise specified. Example 1 Preparation and use of the catalyst of the invention and two conventional catalysts.

Three types of catalysts were prepared by mixing 100 g of the following impregnating solution and 100 g of catalyst support.

Cu(N03)2/pan 20 70th order B
i(N03)3・Mother 20 120g Concentrated HN03 60g The whole was diluted to 1200' with water.

The impregnated catalyst was dried at 120-140q0, then 4
It was fired for 6 hours at 8000C.

Samples of impregnated but not dried catalyst with each support were thoroughly washed with water until no more copper was removed.

No. 1 and 2 lost all of their copper, while 3 exhibited a pale blue color and retained approximately 75% of its original steel content after drying. The above three calcined catalysts were then each used for formaldehyde ethynylation in exactly the same way.

In each case, one portion of the catalyst was added to 500 g of a 10% aqueous formaldehyde solution and steamed under acetylene at high speed in a plated reactor at 80 qo under atmospheric pressure.
Acetylene consumption was measured and recorded. After running for 7 hours each day, the mixture was cooled and allowed to settle. The next morning the solution was removed from the settled catalyst and replaced with fresh 10% formaldehyde aqueous solution. The results are shown in the table below. Table (continued) Table (continued) The data in the above table shows that the calcined catalyst made on magnesium silicate (MS) is much more active than the catalyst on pumice (P), and Although the initial activity of this catalyst was slightly inferior to that of the above-mentioned catalyst (K), it maintained its activity well, indicating that it was superior to the K catalyst from the 12th day onwards.

Results for (K), (MS) and (P) Filtered, washed and vacuum dried catalysts.

Recovered weight: 9.5 g of reddish brown powder of (K) filtered, washed and dried under reduced pressure catalyst.

Recovery weight, reddish brown powder 9 base (P) and 6.1 g (MS
) Analysis sample of recovered catalyst Cul+, % Cu〇, % C
ze+, % C, % day, % residual, % (K) 6.4
3.8 2.4 7.5 0.8
89.4 (MS) 12.1 4.1 3
．． 2 12.2 1.4 75.6 The total number of grams of copper is two samples (K) 1.17 g and (MS) 1.
18g was about the same, but the latter had lost a lot of carrier to leaching and had slightly more carbon and hydrogen.

Furthermore, the proportion of copper remaining in the form of cuprous was very large in MS. The weight loss of MS decreased from about 8% to about 0.8% with magnesium and from about 23% to about 18% with silica. This loss is a process of gradual dissolution of the carrier with continued exposure of additional surfaces of the active catalyst. In the above table, the total of carbon, hydrogen, and remainder is 100%.
The reason for the difference from 00% is due to oxygen.

This is because oxygen is expelled when the catalyst dried under reduced pressure is fired. Note that Cu+1, CU. and C〆1 are included in the remainder. Reference Example 1 Catalyst Generation 60 g of a catalyst powder (made according to the method of Example 1) containing 13% copper and 2.5% bismuth were placed on a magnesium silicate carrier with 50 g of a 10% aqueous formaldehyde solution. .

The mixture was heated to 80°C and acetylene was introduced as required at 80°C. After 7-8 hours, the mixture was cooled and allowed to settle.

The liquid was filtered and replaced with fresh 10% formaldehyde. After each hour further increased activity occurred as a catalyst. Table A *F=formaldehyde, B: butynediol, P=pro/frugyl alcohol, Example 2 Half of the catalyst made in Reference Example 1 was placed in the same reactor with a 25% formaldehyde solution of 4508, and at atmospheric pressure. 80
It was ethynylated with 00.

Table B These examples were carried out in a vessel equipped with a sill plate and fertilized at high speed with a turbine.

The reaction rate was increased even under these conditions with the introduction of a high speed fly and a good control plate. The reactor was flushed with acetylene at the beginning and then a graduated receiver or acetylene was introduced to maintain atmospheric pressure. Example 3 Three experiments were conducted using 10%, 19% and 38% formaldehyde to generate the catalyst log described in Reference Example 1.

The developing fluid did not change until the end of development. After generation was complete, each catalyst was evaluated for ethynylation of 10% formaldehyde. When repeated experiments were performed with 10% formaldehyde, the more active catalysts gradually decreased in activity until after one week they reached the activity of the catalysts generated with 10% formaldehyde.

There was very little change in catalyst activity after this point. Example 4 Effect of Acetylene or Formaldehyde Consumption 10% A catalyst used for an extended period in the ethynylation of formaldehyde was exposed to nitrogen instead of acetylene at 80°C for 6 hours.

After purging the reactor with acetylene, a steady rate of ethynylation was obtained. Analysis of a portion of this catalyst showed that the cuprous metal was not reduced to metallic steel by this treatment. Another catalyst used for extended periods with 10% formaldehyde was tested with 0.2% formaldehyde.

When restored to a 10% solution, the catalyst showed no damage as shown below.

Example 5 Thermal stability of the catalyst of Reference Example 1 and the catalyst of U.S. Pat. No. 3,560,576 A catalyst containing 58-60% copper was prepared as described in U.S. Pat. No. 3,560,576 and was heated under high vacuum. Carefully dried in a vacuum oven at 50-55 qo and then heated in small portions in a porcelain spoon.

A strong flash of light was produced. In the same test conducted with 12 separate samples of the catalyst of the present invention, no explosion occurred and there were no visible signs of ignition. A sample of the catalyst generated in Example 3 containing 12-14% copper was heated to 200 oo in an oven under a nitrogen atmosphere. After cooling, the catalyst
It was used for ethynylation of 0% formaldehyde and gave a rate of about 67% of that obtained before high temperature calcination. Comparative Example 1 Production and Evaluation of Catalyst of U.S. Pat. No. 3,560,576 Reagent grade powder of basic cupric carbonate CuC03/Cu(
OH)2 ratio 0 was made and used for ethynylation in the same low pressure reactor used in the experiments of this invention.

Unlike the catalyst of the present invention, which developed gradually and required 30-6 feed hours to reach maximum activity, this catalyst was produced in at most a few hours. Due to the carbon dioxide produced, the reactor finally had to be evacuated and repurged with acetylene during this catalyst production. Generation with 10% formaldehyde yields a relatively inert catalyst, whereas generation with 19% formaldehyde yields almost exactly the same amount of catalyst of the invention generated at the same concentration of formaldehyde. A new 10% formaldehyde ethynylation catalyst was produced at a rate of 10%.

Example 6 Three-Stage Continuous Butyne Diol Reactor Three 10-gallon steels supported by sufficient gas dispersion turbines are connected in series and the reaction mixture in the overflow of the first reactor is transferred to the second reactor. , the overflow was allowed to enter the third reactor.

The overflow from the third reactor was centrifuged and the catalyst paste was mixed with a fresh source of formaldehyde before being returned to the first reactor. The centrifuged liquid was discharged through a filter to a product storage. To start up the equipment, each reactor was charged with 30 g of 37% formaldehyde and 4K9 of catalyst powder containing 12% copper and 2% bismuth on a magnesium silicate support.

Purge the apparatus with nitrogen, followed by acetylene,
Then, 95 q was heated, and as the acetylene was consumed, acetylene was supplied at the same gauge pressure. 95qo
The acetylene gauge pressure rose to 14 psi.

The experiment was then kept at these conditions. The initial acetylene consumption rate increased as active acetylene generation progressed.

After about 8 hours the rate leveled off and then decreased. At this time, fresh 29% formaldehyde was fed at a rate of 12 evenings/hour, the product was removed from the third reactor, and the catalyst was recycled as described above. After 8 hours of operation in this manner, the apparatus was stable and each reactor contained the bottom composition. Example 7 Catalysts were made by impregnating 10 female catalyst carriers with the following solutions.

Cu(N03) 2・Mushi J20 5 Soko HN03 5g water
65' impregnated catalyst 1
It was dried at 260C and fired at 48000C for 6 hours.

Claims (1)

[Claims] 1 about 5 to about 20% by weight copper in the form of metallic copper and cuprous acetylide, based on the total weight of the catalyst including carrier;
In the presence of an ethynylation catalyst consisting essentially of a water-insoluble cuprous acetylide powder containing 0 to about 3% by weight bismuth and a magnesium silicate carrier, a partial pressure of acetylene is reduced to less than 2 atmospheres with stirring in an aqueous medium. under the pressure of about 6
A low-pressure method for producing butynediol, which comprises reacting formaldehyde and acetylene at a temperature of 0 to 120°C.