JPS6125037B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for the production of bismuth-modified spheroidal malachite and to the production of copper acetylide complexes from such malachite and their use as catalysts.

1,4- by reaction of formaldehyde and acetylene using copper acetylide complex as catalyst
Methods for making butynediol are well known and have been used for many years. As is well known, this reaction is
It produces cuberene which tends to clog the filter and has a negative impact on the process.

One method commonly used to prevent the formation of cuberene during the reaction is to carry out the reaction in the presence of bismuth, either in elemental form or in the form of bismuth compounds. For example, U.S. Pat. No. 3,650,985 (Example 39) discloses that the cublene in the initial step of the process is prepared by directly mixing bismuth oxycarbonate with the basic copper carbonate (malachite) used to form the copper acetylide catalyst. It has been shown that it can be used as an inhibitor. Although the bismuth used in this way prevents the formation of cuberene, it tends to separate from the catalyst after a while, which leads to unsatisfactory results.

One method for handling the separation of bismuth from catalysts is shown in Belgian Patent No. 825,446. According to this, bismuth is introduced into malachite precursors and subsequently by first preparing hydrated copper carbonate particles, converting them to malachite by acting as nuclei and heating these particles. Aggregates of malachite containing bismuth oxycarbonate ( agglomerates). This malachite can be easily converted to copper acetylide catalyst.

Although the bismuth compound in the catalyst thus prepared tends to remain in place, this suggests that the catalyst is composed of agglomerates of angular crystals that are disintegrated by attrition while the putynediol reaction proceeds. Inhibits reaction efficiency.

This problem, as well as the other problems mentioned above, is minimized by the use of malachite and copper acetylide catalysts made in accordance with the present invention. These catalyst assemblies are spheroidal and contain homogeneously dispersed bismuth oxycarbonate.

According to the invention, the spheroidal aggregates of malachite are first hydrated by mixing an aqueous solution of a cupric salt, an aqueous solution of a bismuth salt and an aqueous solution of an alkali metal carbonate or bicarbonate under stirring. Manufactured by forming lumps of copper carbonate. This mixture is then held without stirring or agitation at a temperature below about 55° C., during which spheroidal aggregates of malachite crystals form.

These aggregates are then converted to copper acetylide complexes by slurrying them in water and subjecting them to acetylene and formaldehyde.

Any aqueous cupric salt may be used in the method of the invention. Cupric nitrate, cupric chloride, and cupric sulfate are examples. Cupric nitrate is preferred because of its solubility and availability.

Similarly, any water soluble bismuth salt can be used. Nitrates, oxycarbonates, citrates, sulfates and phosphates are examples. Bismuth nitrate is preferred because of its solubility and availability.

Among the alkali metal carbonates and bicarbonates that can be used, sodium carbonate and sodium bicarbonate are preferred because of their low cost.

Solutions of each salt are prepared such that the solution contains as much salt as possible without precipitation of the salt from the solution upon standing or during use. These solutions are then combined in proportions such that the pH of the resulting mixture is about 5.5-7.5, preferably 6.0-7.0.
In normal cases, this PH range can be achieved by the use of appropriate amounts of alkali metal carbonates or bicarbonates. The bismuth salt is usually present in the resulting mixture in a concentration of 1 to 10% by weight of the copper content.

These solutions are generally combined in any order over a period of 20 to 60 minutes and then mixed by stirring or agitation. In a preferred embodiment, a solution of copper and bismuth salts is prepared and fed into a heel of water simultaneously with a solution of alkali metal carbonate or bicarbonate as shown in Example 1.

It is important to pour these solutions together into a container that has first been washed of malachite kernels by washing with dilute nitric acid.

The resulting mixture is maintained at a temperature slightly above the freezing point of the medium to about 55°C, preferably between 35° and 50°C, with stirring or agitation.
A foot-shaped mass of gel-like hydrated copper carbonate forms immediately.

Malachite aggregates are then prepared from this hydrated copper carbonate by holding the carbonate-containing liquid at approximately the same temperature used in the gel formation step without any stirring or agitation. Ru. Carbon dioxide begins to evolve and malachite aggregates form. This production is usually complete in about 1 to 3 hours.

The malachite produced in this way consists of a spheroidal aggregate of basic copper carbonate crystals. At least about 80% of these aggregates have a diameter of about 5 to 12 in their longest dimension when optically measured against a standard.
It is micron. This aggregate contains 1 to 4% by weight of uniformly dispersed bismuth oxycarbonate, preferably 2 to 4% by weight.
Contains 3% by weight. By "uniformly dispersed" is meant that the oxycarbonate is evenly distributed throughout the mass on a molecular scale.

These aggregates are then separated from the reaction mass by filtration and washed with water to remove free salts. If high concentrations of bismuth are used in the preparation of the aggregates, it is desirable to remove residual gel and smaller aggregates by hydrocloning the reaction mixture before overworking. Hydrocloning, also referred to as hydrocyclone or hydraulic cyclone, refers here to a hydraulic method for removing small particles with dimensions less than about 5 microns. A suitable device for this process is the “Dorr
"Olone".

These malachite aggregates are prepared by preparing a slurry of the aggregates in water and then subjecting the slurry to greater than 2.0 atmospheres in a substantially neutral aqueous medium as described in U.S. Pat. No. 3,650,985 (see column 5). It can be converted to copper acetylide catalyst by simultaneous action of formaldehyde and acetylene at 50-120°C under no partial pressure.

The copper acetylide complex thus prepared is in the form of spheroidal aggregates containing homogeneously dispersed bismuth oxycarbonate in a concentration parallel to that of the malachite from which the complex was prepared.

This complex can be used as a catalyst for the reaction to produce 1,4-butynediol from acetylene and formaldehyde. The complexes are used in conventional manner and in conventional amounts and require no special techniques or measures. Details for such use can be found in US Pat. No. 3,650,985.

Example 1 95g of Cu(NO ₃ ) ₂・3H ₂ O and 10% of concentrated nitric acid in 100ml of water
ml and 1.74 g of Bi(NO ₃ ) ₃ ·5H ₂ O were dissolved. The resulting solution was kept at 35 °C with stirring for 300 min.
ml of water over 40 minutes. Sufficient saturated aqueous solution of Na ₂ CO ₃ was added to maintain the pH of the solution between 6.7 and 7.2.

Stirring was then stopped and the solution was kept at 35°C. The container was filled with blue gel. The gel was reduced to 1/8 of its original volume in about 2.5 hours to form a spheroidal aggregate of malachite crystals. The malachite crystals were separated from the liquid by filtration, washed with water and then heated at 100 °C for 1 hour.
Dry at °C. This product is then transferred to a Dorr-Oliver Hydraulic Centrifugal separator.
Residual gel and small particles were removed by hydrocloning at a pressure drop of approximately 4 atm and room temperature using a 100% Separator (Separator).

At least 80% of the aggregates were between 5 and 12 microns in their longest dimension.

Example 2 45 g of malachite from Example 1, 600 g of formaldehyde (37% aqueous solution) and
2 g of CaCO ₃ was charged. A stream of acetylene containing 90% nitrogen by volume was passed through the vessel at a rate of 2 per minute. Reduce the pressure inside the container to 1.27 to 1.34 atm (4
~5 psig) and the temperature of the reaction mass was maintained at 70°-80°C. The carbon dioxide generated was vented to the outside.

Once the evolution of carbon dioxide had ceased, the contents of the vessel were cooled, removed from the vessel and washed with water.

The resulting copper acetylide complex was stored in water until used.

Example 3 A reactor was charged with 45 g of the copper acetylide complex of Example 2 and 600 ml of formaldehyde (15% aqueous solution). Acetylene was passed continuously through the vessel at a rate of 300 ml per minute and the pressure was maintained at approximately 1.34 atmospheres (5 psig). 37% of formaldehyde
A sufficient amount of aqueous solution was fed to the reactor to maintain the formaldehyde concentration at about 10% by weight. Similarly, a saturated solution of sodium bicarbonate was continuously fed to the reactor to maintain the pH of the contents between 6.0 and 6.2. The product, 1,4-butynediol, was continuously removed by filtration.

After 100 hours of continuous use, the catalyst was removed from the reactor and analyzed by X-ray diffraction scanning. No metallic copper was detected, indicating that the catalyst was stable and useful.

Example 4 The method of Example 1 was repeated using 5.8 g of bismuth nitrate instead of 1.74 g.

The resulting malachite spheroidal aggregate is
It contained 4% by weight of homogeneously dispersed bismuth oxycarbonate.

These aggregates can be converted to copper acetylide catalysts as shown in Example 2, which are then converted into 1.4-
It can be used in the method shown in Example 3 to produce butyne diol.

Claims (1)

[Claims] 1. Substantially each of an aqueous solution of a cupric salt, an aqueous solution of a bismuth salt, and an aqueous solution of an alkali metal carbonate or alkali metal bicarbonate is sufficient to maintain the PH value of the mixture between 5.5 and 7.5. an amorphous gel-like hydrated copper carbonate is formed by combining the amounts under stirring at a temperature below about 55°C and then the mixture obtained above is heated to about 55°C without stirring.
1. A method for producing a copper acetylide complex, which comprises subjecting a spheroidal aggregate of basic copper carbonate crystals obtained by maintaining the temperature below °C as a slurry in an aqueous medium to the action of formaldehyde and acetylene. 2. The method of claim 1, wherein the cupric salt is cupric nitrate, the bismuth salt is bismuth nitrate, and the alkali metal carbonate is sodium carbonate.