DE2363267A1 - CONTACT MATERIAL FOR CLEANING UP OLEFINS AND METHOD OF MANUFACTURING IT - Google Patents

Description

Contact material for purification of olefins and processes too

its manufacture

The invention relates to a material useful for purifying olefins and to a process for its use Manufacturing.

It is known that olefins are purified with the aid of Processes based on the use of absorbents such as silica, aluminum or iron oxide, active carbon, Silica gel, molecular sieves or cupric oxide for the removal of. Based on oxygen. However, the known methods are still difficult with regard to the form of implementation and the conditions Disadvantages on. For example, they are generally used at high temperatures carried out, leading to the occurrence of secondary reactions leads, go that e.g. in the ethylene purification dimers or Form oligomers of low molecular weight which markedly reduce the catalyst activity.

409828/1001

- 2 - 1A-44 097

In BE-PS 687 613 it is proposed to overcome the disadvantages associated with the use of the specified substances, for the purification of olefins feiavertigteas and on To use diatomaceous earth precipitated copper.

With this catalyst "the impurities can be removed at a moderate temperature, especially in the case of ethylene, being at the same time acetylene and oxygen, which with the copper too Acetylide or react to oxide, are bound and water is retained by the microporous carrier.

The material for this known process is obtained by that one has copper sulfate and sodium carbonate in the presence converts diatomaceous earth to basic copper carbonate, adds basic magnesium carbonate to the mass and then streams in the hydrogen. reduced at a temperature at which the water of reaction Will get removed. Although one can obtain one in this way Material can get good results, but these are not always reproducible because the manufacturing process is not in all Cases leads to homogeneously distributed powders. An intimate mix of the metal with the carrier is not guaranteed, so that the .specific surface and thus the specific Activity in the subsequent cleaning process is significantly reduced. In addition, a substance

i.e. made use of basic magnesium carbonate, whereby the safe reproduction of the absorption properties of the material is made difficult. ..

In contrast, it has now been found that you can achieve a high degree of efficiency and a very good reproducibility in the purification of olefins can be obtained when using contact substances those metals of the 1 * B group of the periodic table (Handbook of Chemistry and Physics, 39th edition, Verlag Ghem. Rubber Publ. Co., Cleveland) are finely and homogeneously distributed on a zeolite,

409828/1001

- 3 - 1A-44 097

spherical clay, silica gel, Kieseiguhr or colloidal Silica, stabilized in aqueous suspension, as a carrier. The contact mater! al is obtained with help a process in which a very fine and homogeneous powder is obtained which has a previously adjustable grain size.

In this way, in contrast to the known process, a contact material of the desired particle size is obtained active surface, which has proven to be particularly effective for cleaning olefins. The procedure is anytime Producible, since you have the option of mixing the Control metal with the carrier, so that one ends up. homogeneous powder without coarse metal particles is obtained. Consequently there is only a minimal possibility of olefin purification To use amounts of metal, which contributes significantly to the economy of the cleaning process.

According to the invention, the manufacturing process for the contact material comprises the following stages:

1. Preparation of a suspendible or soluble Verbin-'dung of the relevant metal _t in the case of copper, for example, of the basic carbonate or ammonium complex salt ■;

2. Addition of the carrier chosen in each case to the one obtained Metal compound; .

3. Atomization of the mixture so that the material is in Takes the form of very small spheres (microspheres);

4. Granulating the powder so that you can get the material in one The shape and size that is best suited to the absorption process (e.g. tabletting);

■ 5. Reduce the material in a suitable manner so that the Metal is present in elemental form.

409828/1001

. - 4 - 1A-44 097

When "atomizing" one starts from solutions or suspensions »which contain all components. With a suitable setting of the parameters in question, such as the concentration of the starting solution and the speed of the turbine used to atomize the liquid, a powder is obtained in which the substances in question are very finely and homogeneously distributed. This process step is carried out at a temperature of 110 to 500 ^° C. and particles of 1 to 250 μm can be obtained.

In the use of the contact material according to the invention for the purification of olefins can be carried out at temperatures of -50 to +50 ⁰ C and a pressure of 0.01 to 60 atmospheres work. The olefin is allowed to pass through the contact mass until its activity is exhausted. The metal content of the contact mass is from 1 to 50 and preferably from 5 to 25% by weight. After the treatment, the contact material can be regenerated in a manner known per se, for which purpose, for example, a method is used which is used in the treatment of copper acetylides.

The examples serve to explain the invention in more detail.

example 1

a) For the production of 300 kg Cu / SiO "one dissolves 200 kg CuSO ^. 5H ₂ O in 2000 liters of deionized water. A solution of 84.9 kg of Na ₂ CO-In 1300 l of deionized water is also made up, which is then slowly added to the copper sulfate solution with vigorous stirring. The precipitated basic copper carbonate is centrifuged off and washed with water until the sulphate ion disappears, which contains carbonic acid gas in order to avoid hydrolysis until a more basic carbonate is formed, which is sparingly soluble in ΝΗ, ΟΗ.

40982871001

~ 5 - - 1A-44 097

2363287

50 kg of 43% aqueous ammonia is dissolved in deionized water up to a total volume of 3200 liters. All of the basic copper carbonate is now dissolved in this solution and, after complete dissolution, 1333 kg of SiO ₂ (Ludox AS 30) are added. The "atomizing" takes place with the aid of 300 ⁰ C pre-heated air, so as to obtain a Ausstößtemperatur of 150 ⁰ C erect; the nebulization turhine runs at 7500 rev / min.

In this way you get 300 kg of contact material, some of which collects in the lower part of the nebulizer, while the remainder is obtained by separating the powder from the air stream. The one in the separator centrifuge was used Part of the powder obtained, the mean particle size of which is 50 xub fraud* ' '

2u 1 kg of powder is then added to 800 g of a 1.5% aqueous solution Solution of methyl cellulose (Methocel HG 400} and compressed small cylinders with a diameter of 2 mm and a height of 8 mm »

The material obtained in this way was then first ^{dried in an oven at 120 °} C. and then subjected to a treatment at a gradually increasing temperature under a stream of nitrogen. At 200 ⁰ C, small amounts of hydrogen were introduced intermittently via the nitrogen feed line »

The amount of hydrogen must be chosen so that the material is reduced without excessive overheating. As soon as the Temperature had dropped back to the starting point, hydrogen was introduced again and this was repeated until at further introduction of hydrogen no longer increased in temperature. Then the nitrogen was completely replaced by hydrogen replaced and the treatment continued for another 30 minutes, after which again fed nitrogen and the whole thing cooled to room temperature became. The reduced material was placed under dry conditions

409828/1001.

- 6 - U-4

Stored nitrogen.

The contact material obtained as above was used for the purification of ethylene, that for the polymerization with higher yield was intended *

The degree of purification of the ethylene can only be determined based on the yield in the polymerization; this method is the most accurate inasmuch as in ethylene the impurities in so small amounts are present that they cannot be found in the analysis. .

. In 'a Pfauder autoclave with a capacity of 4 liters after the water and air had been removed, 1 1 became n-heptane containing 1 mmol of AlEt., introduced to wash it. After stirring for 80 minutes at 85 ° C., the wash heptane was drawn off. Now 2.5 liters of n-heptane, which contained 12 mg of AlEt, were again introduced with the aid of a stream of ethylene. Separately from it was 0.09 η grat in 300 ml of n-heptari. TiCl, .AA produced and in abandoned the autoclave. With the. Thermostat, the temperature was kept at 85 G and the ethylene pressure at 6 kg / cm brought. The polymerization was measured by an appropriate measuring device (Flow meter) tracked. -

After 5 hours the autoclave was opened and emptied and the polymer centrifuged off, dried and weighed.

The ethylene was in a column made of stainless steel Steel headed scraper.

The polymer yield (expressed in kg of polymer per g of Ti after 5 hours) was 81 % with a specific efficiency of 2.62. With a specific degree of effectiveness or specific activity

409828/1001

- 7 - 1A-44 097

here is the amount of polymer in kg per g titanium and per kg / cm Meant ethylene.

b) The experiment was repeated, but using the running speed the turbine to atomize the mixture Copper and silica was increased to 15,000 rpm. It was thus reached a particle size of 10 µm.

The copper content of the final product was $ 10. The polymerization of ethylene after going through this purification system gave a yield of $ 93, with the specific activity of the cleaning system was equal to 3 »18. It arises from the Try that the specific activity of the absorbent material is the higher, the lower it is achieved during atomization Particle size is.

c) There are ^{1 is} still carried out comparative experiments in which the polymerization was carried out under the above conditions. The ethylene used had not passed through the cleaning system according to the invention in the first comparative experiment; in the second comparative experiment, it was passed through molecular sieves.

The following results were achieved:

attempt yield specific activity without cleaning system ■ 58 1.87 with molecular sieves 68 · 2.18 Example 2

"The example shows the effectiveness of an Ag / zeolite-Y mixture as an absorbent.

409828/1001

-θ - 1Α-44 097

240 g AgNO ^ were dissolved in 1.5 1 deionized water and 450 g of sodium zeolite Y (SK 40, manufacturer Union Carbide) were suspended in the solution. The suspension was 2 hours stirred vigorously, and then decanted.

The solid was separated, washed twice with deionized water and oven dried overnight at 120 ⁰ C, after which it was calcined for 3 hours in einem- quartz tube at 230 ⁰ C under nitrogen. Finally, the temperature was increased to 420 ^° C. while a mixture of nitrogen and hydrogen was passed through. The zeolite containing the reduced silver was taken up again in 2.5 l of deionized water containing 70 g of NaNO, stirred vigorously for 2 hours, decanted, washed and finally dried in the oven at 260 ° C. overnight. Analysis of the end product showed a content of 22 fo Ag.

When this material was used as an absorbent in the ethylene polymerization according to Example 1, a polymer yield of 84 ° was obtained with a specific activity of 2.72. '

Example 3 '

The example shows the effectiveness of a Cu / zeolite-Y mixture as an absorbent.

This sample was produced as in Example 2. The copper salt solution contained 255 g Cu (NO ^) ₂ .3H ₂ O per liter. 1.5 l of solution were used to suspend 400 g of zeolite; Copper content = $ 18.

The use of this material as an absorbent in the ethylene polymerization according to Example 1 gave a polymer yield of 91 ° with a specific activity of 2.94.

.. 40 9 8287 100 1

- 9 - ■ 1A-44 097

Example 4

The example shows the effectiveness of a g ^ as an absorbent.

To produce this Pxobe, an Al ₂ O, carrier in the form of spheres with a diameter of 1.5 ubi was used, the total porosity of which was OjB cm / g and a surface area of 350 m ² / g.

400 g of this clay were soaked with 300 cm of a 30% copper nitrate solution, which was completely absorbed by the clay. Now the material was 6 hours at 35O ° C under an air stream calcined and then reduced in a tube for 2 hours at 300 ⁰ C with a mixture of nitrogen and hydrogen. The copper content of the final product was 18%.

The use of this material as an absorbent for ethylene polymerization according to Example 1 gave a polymer yield of 76 % with a specific activity of 2.45.

Example 5

The example shows the effectiveness of an Ag / AlpO mixture as an absorbent. The carrier prepared according to Example 4 was impregnated with an aqueous solution of silver lactate which contained 28 $ Ag. After separation of the excess solution, the material overnight -at 120 ⁰ C was dried in an oven under a chromatographic airflow and calcined finally 4 hours at 340 ⁰ C. ■

The final product contained $ 15 Ag.

409828/1001

- 10 - 1A-44

2 ^ 328?

The use of this material as an absorbent for the ethylene polymerization according to Example 1 gave a polymer yield of 71 ° with a specific activity of 2.20.

Claims

409828 / 10.01

ORIGINAL iNSPECTED

Claims (6)

ÄB'Mfβ. ι ·. wuEsrnroirF TO. ING. I>. BEHRKNS - JDIPI ,. INQ. K. GOEXZ β MÜNCHEN OO Pat ent an sprue he 1. Contact material for purification of olefins, consisting of a metal of the first B group of the periodic table finely and homogeneously distributed on a carrier, the carrier being selected is from the following group: Zeolite, spheroidal clay, silica gel, Kieseiguhr, colloidal silica, stabilized in an aqueous suspension. 2. Contact material according to claim 1, characterized by a metal content of 1 to 50, preferably 5 to 25 wt .- ^. 3. Contact material according to claim 1 or 2, characterized by a content of copper or 3 over than Metal. 4. A method for producing the contact material according to a of claims 1 to 3, characterized in that g e k β η η ζ e i c h η e t, that one mixes a previously prepared suspendable or soluble compound of the metal in question with the carrier, the Mixture atomized in such a way that microspheroids are obtained and that powder obtained in this way granulated to the desired size. 5. The method according to claim 4, characterized in that the atomization is carried out at a temperature of 110 to 50O ⁰ C. 4098 28/1001 -f2 - 1A-44 Q97 6. The method according to claim 4 or 5, characterized in that the atomization is carried out in such a way that a particle size of 1 to 250 µm is obtained. 7 · Use of the contact material according to claim 1 "to 3 for cleaning olefins, in particular ethylene, at a temperature of -50 to +50 ⁰ C under a pressure of 0.01 to 60 atmospheres. - * -... 409828/1001 ORIGINAL INSPEGTED