DE2033786B - Process for the production of mixtures of carbon tetrachloride and phosgene - Google Patents

Description

35 phosgene.

Since one molecule of phosgene is produced per atom of oxygen, but at the same time carbon tetrachloride is

It is known. If carbon tetrachloride is to be formed by pressure, the oxygen chlorolysis must be used of benzene or chlorinated aromatic containing carbon-hydrogen compounds, if or chlorinated aliphatic hydrocarbons, they are used alone as a starting material. If suitable working conditions are used, they have one more carbon atom than acidic ions Carbon tetrachloride is practically the only substance atoms present in the molecule, i.e. h., the resulting product, the small amount of the number of carbon atoms must be at least equal to the Anmit occurring hexachlorobenzene as an intermediate product number of O atoms -rl be. If you put a viewed against it must be, since it is circulated and mixed again from oxygen-containing carbon-hydrogen Compounds with aromatic, chlorinated aromatic can be converted into carbon tetrachloride. see chlorinated aliphatic or chlorinated

A process has now been found for the production of cycloaliphatic hydrocarbons development of mixtures of carbon tetrachloride and the latter as starting materials for carbon tetrachloride-phosgene in the absence of catalysts, the substance can be considered; than oxygen-containing coal diameter is characterized in that oxygen-containing substance-hydrogen compounds can then also carbon-hydrogen compounds, some of the bonds are used, which can be substituted by only one carbon atom per or entirely by chlorine, contain only O atoms, so z. B. methanol, ethylene glycol, (In this case, the organic formaldehyde, formaldehyde polymers and acetic acid used, basic substance the number of carbon atoms in the molecule 45 The oxygen-containing carbon-hydrogen verum at least one greater than the number of acid bonds can also be completely or partially through Substitute atoms) or in a mixture with aromatic, chloro-chlorine; for example come into question ated aromatic, chlorinated aliphatic or alcohols such as methanol, ethanol or chlorinated chlorinated cycloaliphatic hydrocarbons with ethanol, ethylene glycol; Propanol or chlorinated Chlorine in an amount between 125 and 400 ° / "for such propanols, such as. B. l-chloropropanol-2, butanols or complete conversion into carbon tetrachloride butanol residues, e.g. B. Oxo syntheses. Phenol or substance theoretically necessary amount at 400 to 800 ° C phenol-containing bodies; Quinones, such as anthra and pressures between 50 and 800 atmospheres, wherein quinone; Aldehydes, such as formaldehyde or formaldehyde or little partially chlorinated organic starting hydpolymers, acetaldehyde or chloroacetaldehyde substances of pre-chlorination at temperatures up to 55 or condensed acetaldehydes; Ketones, such as acetone 400 ° C are subjected. or chlorine-containing ketones, acids, acid esters, acid

It is surprising that in this reaction pre-anhydrides, ketene and diketene residues; Ether table all chemically bound oxygen in or chlorine-containing ethers, such as. B. dichloroisopropyl phosgene is converted. It does not matter in ether or chlorinated diphenyl ether; Epoxies, what form of bond the oxygen at the beginning of the 60 z. B. epichlorohydrin residues or ethylene oxide reaction has existed, for example Aiko polymers; oxygen-containing heterocycles, such as fuol, aldehyde, ketone, carboxylic acid, carboxylic acid ran, furan resins, furfural and coumarone resins.
ester, carboxylic anhydride, ether, phenol, chi- AL · aromatic hydrocarbons come e.g. B.

non-, epoxy or heterocyclic bound acid in question, benzene, toluene, xylene, naphthalene, anstoff in this reaction in the same way in phosgene 65 thracene, diphenyl; chlorinated aromatic carbons. The yield of phosgene, based on the hydrogen, such as chlorobenzene, dichlorobenzene, polyoxygen the converted carbon-oxygen-chlorobenzene, mono- and polychloronaphthalene, mono-compound is very high because it can be excepted and polychlorodiphenyls; chlorinated aliphatic carbon

Hydrogen substances such as chloroform, methyl chloride, vinyl chloride, Polyvinyl chloride, dichloroethane, hexachloroethane, dichloropropane, polychloropropane; whole or rental chlorinated long-chain aliphatic hydrocarbons and chlorinated cycloaliphatic hydrocarbons, such as hexachlorocyclohexane or pentachlorocyclopentane.

Both the non-oxygenated and the Oxygen-containing carbon-hydrogen compounds can be in their group or with one another be mixed in any proportion. Also an admixture of coal or small amounts of inorganic Foreign substances do not interfere with the reaction.

The conversion of the carbon and oxygen-containing reactants nvt chlorine is carried out in the above-mentioned e; Below are listed temperatures and pressures. The reaction runs through several chlorination stages which require different temperatures, so that in most cases a more or ao less strong anchlorination must take place in one or more pre-reaction stages, temperatures of about 0 to 400 ° C. being passed through. Such pre-reaction stages, which normally take place at temperatures below 250 ° C., are necessary in the case of starting materials that are not or only slightly partially chlorinated, because otherwise a violent attack by chlorine can result in coking of the products and thus clogging of the reactor. The actual chlorolytic splitting of the CC bond in the formation of the end products carbon tetrachloride and phosgene only takes place at temperatures above 400 ° C. with an industrially usable reaction rate. Temperatures between 500 ° and 700 ° C. are preferred. A reactor is therefore necessary to carry out the reaction. which contains a pre-reaction zone with temperatures of up to 400 ¹ C in the inlet section and a reaction zone with temperatures between 400 and 8C0 ^r C in the main part. In many cases it is also advantageous to keep a liquid sump in the pre-reaction section, which consists essentially of molten hexachlorobenzene and / or hexachloroethane, into which the starting materials are pumped.

The pressure in the reactor is kept between 50 and 800 atmospheres, a pressure between 80 and 300 atmospheres being preferred is. The pressure in the pre-reaction stage should be the same or, if appropriate, a little lower. the Pressure is achieved by pumping in the starting materials, which are mostly in liquid form. Also chlorine is preferably pumped into the reactor in liquid form. The pressure in the reactor is controlled by a relief valve kept at the desired height. In the main reaction zone of the reactor are the starting materials in the supercritical state, d. H. they are in the gas phase. An exception is made hexachlorobenzene, the vapor pressure of which is so low that it is more finely divided in some parts of the reactor There may be fog.

Chlorine is used in excess. The amount must be at 125-400 ° / ₀ of the theoretically required for the complete conversion of the hydrocarbons in carbon tetrachloride amount. A 50 is preferably up to 100 ° / ₀ hydrochloric excess of chlorine, calculated on the theory used.

An elongated reaction tube has proven itself as the design of the reactor. It will be in the first Te.l. after metering in the starting materials, kept at a lower temperature and serves as a preliminary

reaction zone and then becomes the main reaction zone in the second part at temperatures between 400 and 800 ° C used. However, a different apparatus configuration of the reactor is also possible. For lining of the reactor, nickel has proven its worth. In this case it is then necessary that all starting materials only have a very low sulfur content (<200 ppm).

The chlorination reaction is exothermic. The degree of heat released depends on the amount of the chlorine already bound in the starting material. In most cases you can therefore do so after starting do without external heating in response to the reaction.

The chlorination plant can be operated discontinuously and continuously. The latter being the preferred embodiment is.

The gases leaving the reactor: excess chlorine, hydrogen chloride. Carbon tetrachloride and Phosgene can in the usual way, e.g. B. by distillation, separated and purified.

The excess chlorine is beneficial in the cycle guided. The hexachlorobenzene and / or hexachloroethane formed as a by-product in most cases can also be circulated, completely converting it into carbon tetrachloride. In a continuous cycle, therefore, hexachlorobenzene and / or hexachloroethane is used to be regarded only as an intermediate product that does not appear in the final balance.

From the above it can be seen that the amount of phosgene formed is directly related to the amount the oxygen-containing carbon-hydrogen compound used is dependent. The amount of phosgene can be controlled by additional pumps oxygenated compounds. So you can use a residue z. B. also alcohols, ketones, Add aldehydes, ethers, acids or esters if the phosgene yield is to be increased.

example 1

A vertical reaction tube made of stainless steel for a nominal pressure of 1600 atfi, which contains a nickel lining, is used for the reaction. It has a length of 3300 mm, an outer diameter of 89 mm and a clear width of 40 mm. The reaction tube is divided into a pre-reaction zone and a main reaction zone by means of different heating. The lower electrical jacket heater, which surrounds the reaction tube over a length of 1100 mm, is heated to a maximum of 250.degree. The temperature is measured with an internal thermocouple. This route, which comprises 1.4 1 represents the prereaction zone. The upper electric jacket heating is adjusted so that the internal temperature of the reactor, measured with a sliding thermocouple, between 400 and 800 ⁰ C. This distance, which comprises 2.7 liters, represents the main reaction zone. The space-time yield is calculated on this volume. Chlorine and the starting material mentioned below are pumped in at room temperature at the lower end of the reactor in liquid form using a piston pump. The reaction mixture is withdrawn at the top of the reactor and cooled in a cooler lined with nickel to about 25O ⁰ C. The expansion valve is located at the end of the cooler, with the aid of which the required pressure is maintained in the reactor. The relaxed gases will go through first

a pressureless pre-separator, which is designed as an empty vessel with about 101 contents without special cooling has cooled down. Practically all of the hexachlorobenzene and / or hexachloroethane separates in this vessel away. The reaction gas is then cooled to about -75 ° C. in a cooling coil, with carbon tetrachloride and chlorine condense. The uncondensed hydrogen chloride is measured with a gas meter measured and analyzed for possibly entrained chlorine.

Be at 100 ⁰ C Vorreaktortemperatur In the apparatus described above and 560 ⁰ C main reactor temperature and a pressure of 180 atm per hour

138 g ethanol and * 5

2.3 kg chlorine (= 80% excess)

pumped in.

The following is obtained per hour of end products:

443 g of carbon tetrachloride (= 96% of theory), 290 g of phosgene (= 98% of theory),

25 g hexachloroethane (= 3.5% of theory),

and
655 g of hydrogen chloride (= 100% of theory).

² 5 The yield information in this and the following

Examples always relate to the theoretically calculable amount of the product based on the organic raw material.

B e i s ρ i e 1 2

In the same apparatus as in Example 1 at 100 ⁰ C prereactor temperature and 500 ° C main reactor temperature and a pressure of 240 atmospheres per

35

40

lesson

176 g acetaldehyde (or acetaldehyde distillate

lation residue.) and 3 kg of chlorine (= 110% excess)

pumped in.
The following is obtained per hour of end products:

597 g carbon tetrachloride (= 97% of theory), 390 g of phosgene (= 98.5% of theory),

21 g hexacloroethane (= 2.2% of theory),

580 g of hydrogen chloride.

After the other reaction products have been distilled off, the hexachloroethane becomes an approximately 50% solution pumped back into the reactor in carbon tetrachloride. The excess chlorine that is in a A quantity of around 1.6 kg per hour has to be separated from the other end products, is also again pumped into the reactor.

Example 3

In the same apparatus as in Example 1, a prereactor temperature of 150 ° C. and a main reactor temperature of 66O ° C. are introduced and a pressure of 80 atmospheres per hour

203 g of acetone and

3.2 kg chlorine (= / 0% excess)

pumped in.
The following is obtained per hour of end products:

Example 4

Into the same apparatus as in Example 1 at 100 ⁼ C 550 ⁰ C and Vorreaktortemperatur main reactor temperature and a pressure of 400 atm per hour

440 g ethyl acetate and 5.6 kg chlorine (= 57% excess)

pumped in.
The implementation takes place according to the equation:

CH ₃ - COO - C ₂ H ₅ + 10 Cl ₄

-> 2 CCl ₄ + 2 COCl ₂ + 8 HCl

The following is obtained per hour of end products:

1495 g carbon tetrachloride (= 97% of theory), 960 g phosgene V = 97% of theory),

20 g hexachloroethane (= 1.7% of theory), 14 g hexachlorobenzene (= 1% of theory),

1450 g of hydrogen chloride.

H-xachlorethane and hexachlorobenzene as well as that Excess chlorine is circulated during continuous operation.

Example 5

Into the same apparatus as in Example 1 at 180 ° C and 600 ⁰ C Vorreaktortemperatur main reactor temperature and a pressure of 100 atm per hour

684 g / 9, / 5'-dichlorodiisopropyl ether and 8.2 kg chlorine (= 81% excess)

pumped in.
The following is obtained per hour of end products:

2960 g carbon tetrachloride (= 96% of theory), 385 g of phosgene (= 97.5% of theory),

28 g hexachloroethane (= 3% of theory), 1700 g hydrogen chloride.

Example 6

In the same apparatus as in Example 1, a prereactor temperature of 200 ° C. and a main reactor temperature of 600 ° C. are introduced and a pressure of 80 atmospheres per hour a production residue from the propylene oxide production according to the chlorohydrin process with the following composition:

1130 g 1,2-dichloropropane,

252 g / ϊ, / f-dichlorodiisopropyl ether,

76 g epichlorohydrin,

31 g of 2-methylpentene-2-al-l,

25 g 1 2,3-trichloropropane,

14 g of l-chloropropanol-2, together with

^ss 10.5 kg chlorine (= 67.5% excess)

pumped in.
The following is obtained per hour of end products:

6260g carbon tetrachloride (= 91.4% of theory), 270g phosgene (= 100% of theory),

20g hexachlorobenzene (= 0.4% of theory), 23g of hexachloroethane (= 1.2% of theory), 3100 g of hydrogen chloride.

6o

994g carbon tetrachloride (= 92% of theory), 65 The excess chlorine, the hexachlorobenzene and 335 g of phosgene (= 90.5% of theory), the hexachloroethane, are after the separation

51g hexachloroethane (= 6.1% of theory), pumped back into the reactor and circulated

760 ε hydrogen chloride. guided.

Example 7

Into the same apparatus as in Example 1 at 200 ⁰ C and 600 ⁰ C Vorreaktortemperatur main reactor temperature and a pressure of 300 atmospheres, a mixture of per hour:

280 g phenol,
710 g monochlorobenzene,
210 g dichlorobenzene (mixture of isomers) and
17.4 kg chlorine (= 64 ° / ₀ excess)

pumped in.

The following is obtained per hour of end products:

9100 g of carbon tetrachloride = 96.5 ° / ₀ derTheorie), 290 g phosgene (= 99 ° / ₀ derTheorie)

60 g of hexachlorobenzene (= 2 ° / ₀ derTheorie), 2000 g of hydrogen chloride.

The excess chlorine and the hexachlorobenzene formed are after distilling off carbon tetrachloride, Phosgene and hydrogen chloride circulated and reused in the reactor.

Example 8

The following is obtained per hour of end products:

3410 g of carbon tetrachloride (= 95.5 ° / ₀ derTheorie), 201 g of phosgene (= 97.5 ° / ₀ derTheorie)

23 g hexachlorobenzene (= 1.9% / "of theory), 1200 g of hydrogen chloride.

Example 10

In the same apparatus as in Example 1, g of a production residue from the vinyl chloride production of the following composition are poured into the same apparatus as in Example 1 at 100 ⁰ C prereactor temperature and 600 ^{0 C main reactor temperature and at 80 atmospheres pressure:}

90, percent by weight benzene,
2.1 percent by weight chloral,

3.5 percent by weight dichlorodimethyl ether, 29.7 percent by weight dichlorobutene, 19.5 percent by weight 1,2-dichloroethane,

7.6 percent by weight chlorobenzene,

^ao 6.9 percent by weight tetrachlorethylene,

6.1 percent by weight chloroprene,

2.2 percent by weight of chloroprene dimer, 5.8 weight percent dichloropropene, 4.6 percent by weight of trichloroethane, 3.0 weight percent chloroxylene and 12.0 kg of chlorine (= 113 ° / ₀ excess)

Into the same apparatus as in Example 1 atm at 250 ⁰ C Vorreaktortemperatur and 66o ⁰ C main reactor temperature and a pressure of 80 per hour, a residue mixture of the Oxo-synthesis with about 60% butanol-2 and 30 ° / ₀ 1-butanol and about 10 ° /

unknown oxygenated compounds,

a total of 170 g,
together with 390 g of benzene and

13.0 kilograms of chlorine (= 94 _^0/0 excess)

pumped in.

The following is obtained per hour of end products:

525Og carbon tetrachloride (= 97.8 ° / ₀ derTheorie)

160 g of phosgene (= 100 ° / ₀ derTheorie)

22g hexachlorobenzene (= l, 2 ° / ₀ derTheorie)

13gHexachloräthan (= 0.9 ° / ₀ derTheone)

165 og hydrogen chloride.

Example 9

In the same apparatus as in Example 1, without heating the prereactor and at a ^{main reactor temperature of 650 °} C. and at a pressure of 240 atmospheres per hour, a ^{mixture preheated to about 150 °} C. is discharged

160 g cyclohexanol,
45 g cyclohexanone,

620 g of hexachlorocyclohexane (mixture of isomers from which the y-form has largely been removed) and
7.6 kg chlorine (= 79 ^O / _O excess)

pumped in.

35 pumped in.
The following is obtained per hour of end products:

4920 g carbon tetrachloride (= 95.12 ° / _{0 of} theory), 40 g of phosgene (= 90 ° / _{0 of} theory),

31 g of hexachlorobenzene (= 2.2 ° / ₀ derTheorie)

1400 g of hydrogen chloride.

Example 11

0.88 g of dioxane and 10.0 g of liquid chlorine (= 40 ° / ₀ chlorine excess) are mixed in a tightly closable nickel tube. The nickel tube has a void volume of 90 ml. It is used in a protective tube in a 300 ⁰ C electric furnace hot placed, heated over the course of 20 minutes at 55O ⁰ C and left for 10 minutes at this temperature. The tube is then removed from the oven, allowed to cool at room temperature and, after cooling at one end, opened at the other end. Mainly hydrogen chloride is blown off. The contents of the tube are taken up in pure monochlorobenzene and analyzed by gas chromatography. The following are obtained:

2.65 g carbon tetrachloride and 1.32 g phosgene

With a conversion according to the reaction _{equation C 4} H ₈ O ₂ + 10 Cl ₂ - + 2 CCl ₄ + 2 COCl ₂ + 8 HCl

the carbon tetrachloride-yield is 86 ° / ₀ de theory and phosgene yield 71 ° / ₀ of Theorii The yields would be higher, if not dt some products would have been lost by entrainment with the vaporized hydrogen chloride. Hexachloroethane and hexachlorobenzene were not found.

Claims (1)

Phosgene only contains small amounts of carbon dioxide and Patent claim: possibly determine SrMiröfl von Kohleninönoxyd. This high level of implementation is particularly important for this reason Process for the preparation of mixtures surprising because the equilibrium
Carbon tetrachloride and phosgene in the absence- 5 CO 4- Cl ^ CO Cl ₂ + 26.2 Kcal type of catalytic converter, thereby identifying ² draws that oxygen-containing coal above 50O ⁰ C is already strongly shifted to the left.
substance-hydrogen compounds that are partially or The process according to the invention has the advantage can be completely substituted by chlorine, only that mixtures of oxygen-containing carbon-water (in this case the number of carbon atoms in the starting material must be used in the organic io material compounds used in the used. Even with mixtures that do a large molecule be at least one greater than the number of compounds it contains, there are practically number of oxygen atoms) or in a mixture with only the two end products carbon tetrachloride and aromatic, chlorinated aromatic, chlorinated phosgene. Therefore, an expensive separation of aliphatic or chlorinated cycloaliphatic 15 of the individual components is superfluous. A special hydrocarbons with chlorine in an amount of the importance of the process according to the invention between 125 and 400 ⁰ Z ₀ for the complete is that by-products, residues, waste, conversion into carbon tetrachloride theoretically rejects and similar substances of chemical necessary amount from 400 to 800 ⁰ C and manufacturing processes, insofar as they implement the required additional pressures between 50 and 800 atmospheres, with such a composition, can be used. The non- or slightly incipiently chlorinated organic training method of the invention therefore allows a transition materials of a pre-chlorination at temperatures residue-free utilization are subjected by most unpleasant Abfallbis to 400 ⁰ C. fabrics and also produces them on a large scale valuable compounds carbon tetrachloride and