DE1197060B - Process for removing contaminants from liquids - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

BOId

German KL: 12 d- 1/03

Number: 1197060

File number: B 53317IV a / 12 d

Filing date: May 22, 1959

Opening day: July 22, 1965

For many technical needs, solvents or liquids are required that are free from Oxygen or certain compounds containing nitrogen, sulfur or oxygen. So is z. B. the petroleum processing industry is interested in crude oil or certain gasoline fractions To get oxygen or sulfur free. Especially the chemistry of the organometallic compounds places very high demands on the purity of the solvents, because the highly reactive Metal alkyls are formed by oxygen and by many that contain oxygen, nitrogen or sulfur Any contamination of the solvent is destroyed. So far, those for the organometallic reactions have been purified needed solvents by heating them with alkali metals or metal alkyls and then distilled. However, such a procedure is dangerous, lengthy and costly.

Furthermore, a method for purifying sulfur-containing hydrocarbons is known in which copper in compact form or in the form of copper parts or copper shavings used as a cleaning agent will. However, additional measures are required here (brushing off the copper surface, pretreatment of hydrocarbons and alkaline or reducing substances) without the the copper masses used would lose their cleaning power in the presence of peroxides, aldehydes and acids.

It has now been found that the inorganic impurities oxygen, halogens, hydrogen peroxide, hydrogen sulphide, sulfur dioxide, hydrogen halide, carbon oxysulphide and metal carbonyls or the organic impurities acetylene compounds, thiophene and organic peroxides are advantageously removed from organic solvents if the organic solvent is reduced over large surface areas , copper-containing masses that contain magnesium silicate or iron oxide as a carrier. The process of the invention the organic solvent to be cleaned can belong to a wide variety of classes. Saturated and unsaturated aliphatic and cycloaliphatic as well as aromatic hydrocarbons, chlorinated hydrocarbons, ethers, alcohols and esters can be subjected to the process. Specifically, for example, n-heptane, isooctane, cyclohexane, cyclohexene, methylcyclohexane, benzene, toluene, chlorobenzene, carbon tetrachloride, trichlorethylene, methanol, ethanol, diethyl ether, dibutyl ether, tetrahydrofuran, dioxane and ethyl acetate may be mentioned. Beson process for removing contaminants from liquids

Applicant:

Aniline & Soda Factory in Baden

Aktiengesellschaft, Ludwigshafen / Rhein

Named as inventor:

Dr. Max Schütze, Ludwigshafen / Rhine; Dr. Herbert Müller, Frankenthal (Palatinate); Dr. Peter Rudolf Laurer, Ludwigshafen / Rhine

The new process for the pretreatment of liquids for organometallic liquids can also be advantageous Use conversions to be used. Even substances that under normal conditions Are not liquid, can be cleaned by passing them through the process Pressure liquefies if it is a gas, or it liquefies at an elevated temperature in the molten state Brings state with the copper-containing mass in contact. Another option, gases or solid To purify fabrics consists in finding suitable solutions of the same in the manner according to the invention treated. Of the substances to be cleaned that are gaseous or solid under normal conditions for example propylene, butane, butadiene (1,3), naphthalene and durol called.

The impurities that are removed in the manner of the invention are more inorganic or organic in nature. The inorganic impurities can be as elements or in In the form of compounds. The new method can be used preferably for removal use contaminants that are gaseous under normal conditions.

In the highly active, large-surface, copper-containing masses, the copper is finely divided Shape before; they are advantageously produced by precipitation from aqueous solution. It can be z. B. use the hydrogenation catalysts known from German Patent 869 052. she

509 627/226

consist of copper and magnesium silicate and are made by common precipitation or by Precipitation of copper compounds obtained on precipitated magnesium silicate. The Indian German patent 869052 recommended addition of activators, such as compounds of alkaline earths, of zinc, cadmium, chromium, molybdenum, tungsten, vanadium, titanium and / or thorium, is beneficial in some cases. Another suitable compound contains copper and iron oxide. Finally, in many cases, a copper-containing compound can be used with advantage, which additionally still contains small amounts of gold. The weight ratio of the copper to the other ingredients can be between 1:20 and 20: 1. The other ingredients are optional reduced before they are used for cleaning liquids, advantageously with carbon monoxide, Hydrogen or gas mixtures containing these. It is easy to decide which one by experimentation Composition or which carrier material for the removal of certain impurities on the is best suited. So one achieves z. B. in the removal of hydrogen sulfide from liquefied or dissolved propylene with the catalysts known from German Patent 869 052 better Results than with those masses which contain iron oxide in addition to copper. on the other hand allow the latter masses in many cases - z. B. in the removal of molecular Oxygen - higher flow rates than those mentioned first.

The purification according to the method of the invention can be carried out within a wide temperature range. The copper-containing compounds are so active that even at room temperature and even at low temperatures, e.g. B. at 0 to -20 ⁰ C, satisfactory throughputs are possible. In some cases, however, the use of elevated temperatures, for example between 40 and 150 ^° C., is advisable.

The process according to the invention can be carried out continuously and discontinuously. in the In the latter case, the substance to be cleaned and the copper-containing mass will take some time, if necessary with stirring, brought into contact with each other. The continuous cleaning is expedient in a tube, in which the liquid is swamped or trickled over the fixed mass leads. The exiting liquid is usually so pure that a No need for distillation. The flow rates depend on the solvent, the type and degree of contamination, the temperature and the activity of the copper-containing mass and are in the Usually 5 to 10 room parts per room part of copper-containing carrier and hour.

When the purified liquids for reactions involving organometallic compounds are to be used, it is advisable to remove the above-mentioned impurities with an elimination of water and / or carbon dioxide. One can use the copper-containing mass and a water and carbon dioxide binding agent in a flow tube arrange. So z. B. first the water with aluminum oxide, then carbon dioxide with caustic potash and finally oxygen or the other mentioned impurities by means of the described Remove the copper-containing mass.

The possible operating time depends primarily on the degree of contamination of the liquid. It may be many days. The consumed copper-containing compounds can easily be reactivated by treating them with a reducing gas at an elevated temperature. It is advantageous to use hydrogen or carbon monoxide for this purpose. If the mass was used to remove sulfur compounds. In any case, it is advisable to first treat it with oxygen-containing gases. The most favorable temperatures for reactivation are between 50 and 300 ^° C.

Example I.

Through a vertical cleaning column, the lower part with 200 room parts reduced copper-magnesium silicate catalyst manufactured according to German patent 869 052 above with 100 parts of caustic potash and in its upper part with 200 parts of space anhydrous y-aluminum oxide is charged, 1000 parts of the volume of benzene are allowed to trickle every hour.

To determine the proportion of substances that destroy organometallic compounds, the cleaned Benzene titrated with an ethereal solution of phenylisopropyl potassium (cf.K. Ziegler, "Liebig's Annals of Chemistry". 437 [1924]. P. 265). 1 ml of a 0.03 molar solution is used 700 ml of benzene decolorized. That equates to about 0.5 ml of oxygen per liter of benzene when you consider all the impurities calculated as oxygen.

On the other hand, if benzene is allowed to trickle down a column under otherwise identical conditions, it does not Contains copper catalyst, 7 ml of phenylisopropyl potassium solution discolored by 100 ml of benzene, which corresponds to about 25 ml of oxygen per liter of benzene.

Example 2

A mass is used which is obtained by precipitating copper hydroxide and iron hydroxide together and after reducing it contains about 30% copper, and leaves over 200 parts by volume of this catalyst trickle down 500 parts by volume of cyclohexane within 30 minutes. In The oxygen content of the cleaned liquid is determined with the help of an alkaline solution of iron (II) and manganese (II) salts. as described in "Analytical Chemistry", 28 (1956), p. 1490 is. The cyclohexane contains less than 0.03 ml of oxygen per liter, while im untreated cyclohexane contains 30 ml of oxygen per liter.

Example 3

Under the conditions described in Example 2, n-heptane is obtained with a 0.4% gold containing reduced iron-copper hydroxide mass purified. It is practically obtained this way oxygen free.

Example 4

Chlorobenzene is treated under the conditions described in Example 2 and a Product that has less than 0.03 ml of oxygen per liter.

B e i s ρ i e 1 5

In a pressure tube, 60 parts per hour of liquid sulfur-containing propylene are passed under a pressure of 10.5 atmospheres per hour over 9 parts by volume of a catalyst obtained by precipitating basic copper carbonate on precipitated magnesium silicate and treating with hydrogen at 150 ^{° C. and containing 28% copper} . The temperature in the catalyst zone is 5 ^° C. The sulfur content of the purified propylene is below 0.2 mg of sulfur per liter of liquid propylene, while the starting material contained 10.8 mg of sulfur per liter. With 1 volume part of the catalyst, 2000 volume parts of liquid propylene can be cleaned without regeneration.

Example 6

A methanol produced by large-scale synthesis and containing 0.9 mg of iron per liter in Form of iron carbonyl and containing 1.7 mg of chlorine per liter, is passed through over a reduced copper catalyst, as used in Example 5, purified at room temperature. The iron content is then 0.2 mg per liter and the chlorine content 0.9 mg per liter.

Example 7

The mixture is allowed peroxydhaltiges tetrahydrofuran at 2O ⁰ C at a rate of 1 1 per liter of catalyst and per hour through the runner used in Example 1 reduced copper catalyst. According to the usual methods, no peroxide can be detected in the product that has passed through.

Diethyl ether can also be freed from peroxides under the same conditions.

Example 8

Liquid butadiene, which contains 5 ppm of oxygen, is allowed to ^{trickle in a pressure tube at 30 °} C. at a rate of 1 liter per liter of copper-containing carrier and hour over the reduced copper-containing mass used in Example-2. No more oxygen can be detected in the butadiene purified in this way. The butadiene was not changed by this operation.

Example 9

100 parts by volume of ether containing peroxide, the 4 mmol Release iodine from an acidified potassium iodide solution and contain 0.1 volume part thiophenol, are at room temperature over the reduced copper catalyst used in Example 1 directed. In a sample of the product that has passed through there is only 0.01 part by volume of thiophenol per 100 parts by volume Ether and no more peroxide detectable.

Claims (1)

Claim: Process for removing oxygen, halogens, hydrogen peroxide, hydrogen sulfide, Sulfur dioxide, hydrogen halide, carbon oxysulphide and metal carbonyls or acetylene compounds, Thiophene and organic peroxides from organic solvents, characterized in that the Conducts organic solvents over large areas of reduced copper-containing masses, which act as carriers Contain magnesium silicate or iron oxide. Considered publications:
German Patent Nos. 537 433, 649 589, 640 204, 726 680, 958 233, 961 647. 509 627/226 7.65 © Bundesdruckerei Berlin