JPS5825649B2 - chlorolysis chinensis - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION C by the action of chlorine at high pressure and temperature
The so-called chlorination decomposition (Chlor decomposition) in which the -C bond is split
In the reaction known under the name lysis, carbon tetrachloride is formed as the final product in each case.

Furthermore, whether and what other products are formed during this reaction depends on the organic material charged.

If hydrocarbons which can be wholly or partially chlorinated are also used, carbon tetrachloride is formed as practically the only reaction product.

If oxygen-containing compounds are used, phosgene is also formed in addition to carbon tetrachloride.

When using fluorinated hydrocarbons or compounds containing hydrogen fluoride, fluorinated chloromethane is formed in addition to carbon tetrachloride as the final product.

Furthermore, since tetrachlorethylene is one essential component of the reaction product, all these reactions are very easy to control.

All these reactions are carried out in a temperature range of 400 to 800°C and a pressure range of 50 to 700 atmospheres (gauge pressure).

Owing to the extremely high aggressiveness of the chlorine and, in almost all cases, the hydrogen chloride formed in the pressure and temperature ranges mentioned, these reactions have to be carried out in pressure vessels in which the parts in contact with the products are made of nickel. .

However, since nickel no longer has sufficient strength at these high temperatures, a steel jacket must be used as the pressure-bearing element, which still has sufficient strength even at high temperatures.

For the industrial implementation of these reactions, reactors made of heat-resistant steel with a nickel lining are therefore required.

It has now been found that such reactors can become leaky after only a few hundred hours of operating time, thus rendering them impossible to operate in industrial production facilities.

Leakage, which rapidly leads to destruction of the reactor due to the evolution of chlorine and hydrogen chloride at the high temperatures and pressures used, is primarily due to corrosion of the nickel lining.

It has now become clear that these difficulties can be overcome if certain working materials are used and certain conditions are strictly adhered to in the construction of reactors suitable for this reaction.

The subject of the invention is aliphatic, cycloaliphatic or aromatic compounds and/or their chlorinated products or their use products at temperatures of 400° to 800° C. and 50 to 700 atmospheres (gauge pressure). In a reactor for the chlorination decomposition of a mixture of
．． A pressure support mantle made of heat-resistant steel with a carbon content of 0.015% by weight or less and a carbon content of 0.08% by weight or less;
% by weight or less and its carbon content is 0.02% by weight or less.

A reactor characterized in that it consists of a nickel lining without weld seams or weld points, the surfaces of both reactor components being free of carbon- and sulfur-containing impurities.

The reactors according to the invention, despite the chemical loading with chlorine and hydrogen chloride and the simultaneous physical loading with pressures up to 700 atmospheres (gauge pressure) and temperatures up to 800° C. Indicates the usable period in years.

Nickel, which is subject to significant corrosion losses due to the passage of chlorine and/or hydrogen chloride at temperatures above 500° C., can be treated by taking into account the conditions according to the invention.
i.e. 0.0 at a minimum content of 99% by weight of nickel.
It is surprising that a sulfur content of less than 1% by weight and a carbon content of less than 0.02% by weight provides sufficient resistance.

Moreover, it was also surprising that only the welded seamless nickel lining of such a reactor could survive under the conditions mentioned.

This is because it is known that low pressure chlorination processes, such as the chlorination of methane to carbon tetrachloride, may be carried out in welded nickel reactors.

Moreover, in the case of the carbon and sulfur contents of nickel mentioned above, a durability of much longer than one year is demonstrated, whereas sulfur and carbon contents above the mentioned range lead to very rapid changes in the structure of nickel. It was not foreseen that it would cause such destruction.

Similarly, a sulfur content of less than 0.015% by weight and a carbon content of less than 0.08% by weight of the pressure-supporting steel jacket of the reactor will also play a vital role in longevity. was also unexpected.

Further thorough cleaning during assembly of the reactor ensures that the surfaces of both reactor components are free of carbon- and sulfur-containing impurities, e.g. in the form of oils or fats or cutting aids. It is preferable to do so.

Therefore, before inserting a nickel pipe into a steel pipe, the surface should be cleaned with a fat-dissolving agent, such as acetone, carbon tetrachloride, trichlorethylene or the like, and dried or washed free of all foreign substances with demineralized water. have to drop it.

Example reactor has length 3300mm, outer diameter 891m and inner diameter 4
Manufactured from 5mm steel pipe.

An austenitic steel with the following composition is used: CO,
044% by weight S O,007//Cr
16.9 ttN
i 13.5
ttMo 1
．． 2 ttFe and others (V, Ta, Nb, N2, etc.) For the nickel lining of the residual sound 5 steel t, a seamless nickel tube with a wall thickness of 2.75 mm and an external diameter of 44.5 mm is used.

This nickel has the following composition: Ni 99.0% by weight CO,
015% by weight SO, 005〃F
e, Ti, Cu, Si, Mn
Before fitting both remaining tubes together, thoroughly clean them by several soaks and rinses in acetone, then several rinses in demineralized water, and dry.

The nickel tube inserted into the steel tube is flanged at both ends, creating a gas-tight surface for the attachment of the high-pressure lens.

After this manufacturing process, the nickel tube is pressed against the steel tube from the inside by water pressure.

Such a reactor, arranged upright and connected in the lower part via a lenticular body with a distribution device and in the upper part via a lenticular body with a cooling device and a pressure relief device, is Used for chemical decomposition.

For example, in this reactor, 260-300 atmospheres (gauge pressure)
The following mixtures are fed per hour at a pressure of
35 gupentachloroethane 70 ghexachloroethane 3900f dichloroethane 6501 chlorine
7,000 grams per hour, then 10,600 grams of carbon tetrachloride and 85 grams of a mixture of hexachloroethane and hexachlorobenzene.
1 is obtained.

This reactor was operated for more than one year without any technical failures.

Claims (1)

[Claims] Temperatures of 1400° to 800°C and 50 to 70
At a pressure of 0 atmospheres (gauge pressure), the sulfur content is A pressure jacket made of heat-resistant steel having a carbon content of not more than 0.015% by weight and not more than 0.08% by weight; and a nickel lining with no weld seams or points, the carbon content of which is less than 0.02% by weight, the surfaces of both reactor components being free of impurities containing carbon and sulfur. A reactor for chlorination decomposition characterized by the following.