JPS5917086B2 - Method for oxychlorination of ethylene and catalyst composition used therein - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention provides a fixed catalyst bed oxychlorination method for ethylene;
More particularly, it relates to a process for oxychlorinating ethylene over a fixed catalyst bed to obtain chlorinated hydrocarbons, particularly 1,2-dichloroethane.

It is known that chlorination occurs when a hydrocarbon such as ethylene is reacted with a gas containing hydrogen chloride and oxygen, especially air, in the presence of a catalyst under heat and pressure.

Such a method is called “oxychlorination (Oxych10rin
DeacOn process generally uses a catalyst consisting of a chloride of at least a divalent metal supported on a porous refractory support. The most common catalysts used in such processes are cupric chloride supported on particulate materials such as activated alumina, silica, alumina-silica, and diatomaceous earth. Activated alumina, in each of its various forms, is by far the most commonly utilized support. In addition, the catalyst may include alkali metal chlorides, rare earth metal chlorides, and other metal compounds that promote the desired reaction and/or
Alternatively, it may contain additives that inhibit the progress of side reactions. Potassium chloride has been used as an additive to such catalysts, particularly when attempting to produce 1,2-dichloroethane from ethylene. This is because potassium chloride is known to inhibit the production of ethyl chloride. However, the amount of potassium chloride must be small, which also tends to reduce the catalytic activity for the main reaction. One of the points to be noted when carrying out such a fixed bed oxychlorination method is control of the reaction temperature.

The oxychlorination reaction itself is a highly exothermic reaction, and the catalyst bed itself has low thermal conductivity, making it difficult to control the reaction temperature. As a result of these two factors, there is a risk of localized zones with undesirably high temperatures forming in the catalyst bed. Thus, such exceptionally high localized temperatures are prevented. Or at least, many efforts have been made to reduce it. For example, adjusting the proportions of the reactants, or diluting the feed with an inert gas or an excess of one or more reactant gases, or providing controlled external cooling, and/or using various diameters. The temperature can be controlled in various ways by using reaction tubes with tubes, by diluting the catalyst particles with inert particles, or by varying the size of the catalyst and/or inert particles. Proposed. In particular, it is known that when the reaction is carried out in a reaction tube, as described for example in U.S. Pat. ing.

This is a result of the nature of the oxychlorination reaction itself, which becomes less and less intense along the flow direction of the reaction mixture. At the inlet of the catalyst bed, the reaction proceeds rapidly and vigorously, and control of both the temperature and the hot spot (highest temperature point) is important. However, as the reactants pass through the catalyst bed, oxygen is consumed and the reaction becomes somewhat less vigorous. This is particularly problematic because, as is known in the art, the oxychlorination process
This is the case when several catalytic reactors are arranged in series and the entire air (or oxygen) feed is divided into several reactors. That is, as the oxychlorination feed mixture reacts, oxygen is being consumed near the outlet of each reactor, leading to uncontrollable reactions in this region or unreasonably high localized temperatures. This is less of a problem than in the reactor section closer to its inlet. One proposed solution to not only significantly control the reaction temperature and the formation of localized high temperatures, but also to significantly increase the conversion and selectivity of dichloroethane, is to replace the catalyst with inert particles. It is diluted with a mixture of particles.

Inert particles used for this purpose include, for example:
Examples include silica, alumina, graphite, and glass beads. Depending on the process, the proportions of catalyst and diluent in the oxychlorination reactor vary. On the inlet side of the reactor,
It is desirable to use a lower concentration of catalyst due to the risk of reaction or localized high temperatures. However, in the depths from the entrance, the reaction progresses and its intensity becomes weaker.
These risks are not so significant that it is in fact preferable to use a more active catalyst to continue to accelerate the reaction as oxygen is consumed. That is, when using a diluted catalyst, the catalyst bed is divided into two or more zones, each zone containing a different proportion of catalyst and diluent, and closer to the exit of the reactor. It is common to increase the ratio of catalyst to diluent. For example, Example 1 of U.S. Pat. No. 3,184,515 describes a diluted catalyst method in which the reaction tube is divided into four zones, the first contains 7% (by volume) catalyst and 93% (by volume) graphite diluent, the second zone having a volume percent ratio of catalyst to diluent of 15:85; The third zone is a 40:60 mixture of catalyst and diluent, and the fourth zone contains 100% catalyst.

In another variant, a fairly highly active catalyst is placed directly near the reactor inlet to initiate the reaction, and a less active catalyst is introduced shortly after to create hot spots in adjacent zones. is prevented. However, there are several disadvantages to using diluted catalysts as described above.

First, since the catalyst must be charged to several different reaction zones, several different proportions of catalyst and diluent mixtures must be prepared. However, a problem that must be addressed is that when the catalyst and diluent are mixed, a non-uniform mixture is formed. Therefore, if the mixing is not satisfactorily thorough, the concentration of catalyst particles in certain parts of the reaction zone can create undesirable localized high temperatures. Furthermore, in many cases, the diluent particles are not the same overall size or shape as the catalyst particles.
Therefore, it has been proposed, for example, to use diluent particles of different shapes or sizes to form cylindrical or spherical catalyst particles. In such cases, it is not advantageous for the entire mixture to have a fairly inhomogeneous surface to the reaction reagents and pressure and/or that a pressure drop occurs during the reaction. Even if the diluent particles have the same relative shape or size as the catalyst particles, different reactions may occur, with the possibility that the diluent and catalyst will not mix satisfactorily, resulting in hot spots. A tedious process is required in which different catalyst-diluent mixtures must be prepared for each zone. Another proposed solution is
Regardless of the presence or absence of a diluent, the size of catalyst particles is made smaller from the inlet side to the outlet side. Such a concept is described in US Pat. No. 3,699,178. However, such a process also requires careful manufacturing to obtain the particle size as described, even if the catalyst is utilized without diluent, and to achieve the objectives of this concept. requires the creation of at least two, and perhaps three or four, different catalysts. Another concrete measure of this idea is
Although there are methods of mixing the catalyst with diluent particles, the use of diluent particles makes the disadvantages of producing catalyst particles of different sizes even more disadvantageous. The object of this invention is to provide an oxychlorination process for producing 1,2-dichloroethane from ethylene.

Another object of the invention is an oxychlorination process for producing 1,2-dichloroethane from ethylene, comprising:
Therefore, it is an object of the present invention to provide a method in which hot spot formation and temperature can be easily controlled.

Another object of this invention is to provide a process for producing 1,2-dichloroethane by oxychlorination of ethylene at high conversion of hydrogen chloride.

Yet another object of the invention is to provide a method in which a substantially uniform pressure drop is maintained over a considerable period of time.

Another object of the present invention is to provide a method in which the conversion selectivity of ethylene to 1,2-dichloroethane is very high and the excess amount of reaction reagents such as ethylene and/or air can be kept to a minimum. It is to provide.

Yet another object of the invention is to provide a process that can be carried out using high flow rates of the reactants.

Yet another object of this invention is to provide a system and method for oxychlorination of ethylene that can be carried out using air or oxygen as the oxygen-containing gas.

Furthermore, the present invention provides a method for using ethylene, which has the above-mentioned advantages.
- The purpose is to provide a new catalyst for use in the oxychlorination of 2-dichloroethane.

The outline of this invention consists of a novel oxychlorination method utilizing a novel catalyst consisting of cupric chloride and potassium chloride on spherical activated alumina having a large surface area and high structural integrity.

Such a catalyst is used in a series of three reactors, the catalyst being used substantially in the absence of an inert diluent, and the content and weight ratio of cupric chloride and potassium chloride in the catalyst being of ethylene by changing in each reactor.
The conversion of 2-dichloroethane is carried out at high conversion and selectivity rates, with good hot spot suppression, and over long periods of time with little pressure drop. In each of the first two reactors, the catalyst bed is divided into two zones, with the catalyst in the zone near the inlet preferably containing somewhat lower cupric chloride than the catalyst in the zone near the outlet. content, and the weight ratio of potassium chloride to cupric chloride is high. Another object of the invention is also a reaction system for carrying out the oxychlorination process, which consists in arranging the catalyst described above in a reactor as described above.

More particularly, according to one object, the invention is a fixed bed oxychlorination process for ethylene, which comprises: (a) a first portion of ethylene, hydrogen chloride, and an oxygen-containing gas; in the second reaction zone substantially undiluted by catalytically inert particles, and the cupric chloride and potassium chloride are supported on activated alumina spherical particles. The first catalyst bed is divided into two parts in the flow direction of the reactants, the first part containing about 45% of the catalyst bed. and the second portion comprises from about 25% to about 55% of the catalyst bed.
%, and the first portion comprises about 4.5% of cupric chloride.
5% to about 12.5% (by weight) of potassium chloride and about 1.5% to about 7% (by weight) of potassium chloride, the weight ratio of cupric chloride to potassium chloride being about 1.5. vs 1 and about 4
and the second portion is between about 12 and about 25% (by weight) cupric chloride and about 0% potassium chloride.
．． 5 to about 4% (by weight), and the weight ratio of cupric chloride to potassium chloride is about 5 to 1 and about 1.
(b) combining the product of step (a) above and a second portion of oxygen-containing gas in a second reaction zone with catalytically inert particles; the second catalyst bed, substantially undiluted, and comprising cupric chloride and potassium chloride supported on spherical particles of activated alumina; The second catalyst bed is divided into two parts in the direction of flow of the reactants, the first part being about 45% to about 75% of the catalyst bed.
%, and the second portion comprises about 2% of the catalyst bed.
5% to about 55%, the first portion of the catalyst bed comprising about 5.5 to about 15% (by weight) cupric chloride and about 1
from about 5% (by weight) of potassium chloride, the weight ratio of cupric chloride to potassium chloride being from about 2:1 to about 6:1, and the second portion from about 12 to about 1% by weight. 25
% (by weight) of cupric chloride and about 0.5 to about 4% (by weight) of potassium chloride, in a weight ratio of cupric chloride to potassium chloride of about 5:1 to about 15:1. and (c) substantially diluting the product of step (b) above and a third portion of oxygen-containing gas with catalytically inert particles in a third reaction zone. and about 12 to about 25% (by weight) of cupric chloride and about 0.0% (by weight) of potassium chloride in the activated alumina spherical particle soil.
5% to about 4% (by weight) of the catalyst supported on the catalyst in a ratio of cupric chloride to potassium chloride of about 5:1 to about 15:1 by weight. It consists of a process.

Another subject of the invention is a catalyst composition consisting of cupric chloride and potassium chloride supported on a substrate consisting of spherical particles of activated alumina, the substrate comprising about 225 to about 2
BET surface area of 75 i/7, friction strength of at least 90%, total nitrogen pore volume of about 0.3 to 0.6 cc/7, about 5
Average pore diameter of 0 to 100λ and about 20 to about 5
0% of the pore volume is constituted by pores with a diameter of about 80 to about 600λ, and further includes X as described below.
characterized by a line diffraction pattern, and H
The catalyst composition consists of no grain boundaries as observed after etching with F.

A third object of the invention is a reaction system for the oxychlorination of ethylene in the presence of a catalyst consisting of cupric chloride and potassium chloride supported on spherical particles of activated alumina, which reaction system comprises (a ) the first reaction zone is divided into two parts along the flow direction of the reactants, the first part occupying approximately 45% of the catalyst bed;
and the second portion comprises from about 25% to about 55% of the catalyst bed, and the first portion comprises from about 4.5% to about 12.5% (by weight). cupric chloride and about 1.5% to about 7% (by weight) potassium chloride, with a weight ratio of cupric chloride to potassium chloride of about 1.5:1 to about 4:1. and,
The second portion is comprised of about 12 to about 25% (by weight) cupric chloride and about 0.5 to about 4% (by weight) potassium chloride; the weight ratio is between about 5:1 and about 15:1, and (b) the second
The second reaction zone is divided into two parts along the direction of the reactants, the first part being about 4.5 m above the catalyst bed.
and the second portion comprises from about 25% to about 55% of the catalyst bed, and the first portion of the catalyst bed comprises from about 5.5 to about 15% (by weight). cupric chloride and about 1 to 5% (by weight) potassium chloride, the cupric chloride to potassium chloride weight ratio being between about 2:1 and about 6:1; and the second portion comprises about 12 to about 25% (by weight) cupric chloride and about 0.5 to about 4% (by weight) potassium chloride;
the cupric chloride to potassium chloride weight ratio is between about 5 to 1 and about 15 to 1, and (c) the third reaction zone is about 12 to about 25% (by weight) of cupric chloride and about 0.5 to about 4% (by weight) of potassium chloride, with a weight ratio of cupric chloride to potassium chloride of about 5.
A fixed bed oxychlorination reaction system of ethylene comprising a third catalyst bed comprising between 1:1 and about 15:1.

The catalysts of this invention are prepared by conventional impregnation methods utilizing aqueous solutions of cupric chloride and potassium chloride, as described in the Examples below.

The impregnated carrier is activated alumina, which is a spherical particle with a large surface area. That is, it has a BET surface area of at least 100 m2/y, preferably from about 225 to about 27
5 m2/7, a friction hardness of at least 90%, a total nitrogen pore volume of 0.3 to about 0.6 CC/y, and an average pore diameter of about 50 to about 100λ, of which fine About 20 to 50% of the pore volume is about 80 to about 600
It consists of pores with a diameter of λ. This alumina further has three major peaks, namely a diffuse peak at 1.39λ and 1.98λ and another peak at 2.34λ, with its peak at 1.39A and 1
．． by an X-ray diffraction pattern with an intensity ratio of about 1.5 to 1 to 5 to 1 with the peak at
After etching with F, virtually no crystals can be observed (G
rain) characterized by the absence of boundaries. Supports with these properties have good structural integrity even during long-term operation. An example of a suitable carrier of this type is the trade name "HSC-114" [HOudry Process & Chemical Company (HOudryP
rOcessandChemicalCompany)]
and “SCM-250” [Rhoneprodil (RhO
Examples include alumina commercially available from nePrOgil).

The present invention will now be described with reference to the drawings showing exemplary flow sheets for carrying out the methods of the present invention and for utilizing the catalysts and systems of the present invention.

In the drawing, the process according to the invention is carried out in three reactors arranged in series, designated R1, R2 and R3.

Each reactor contains a catalyst bed designated 12, 14 and 16, respectively, and are preferably tubular reactors having tubes filled with catalyst. Reactor R1
, the catalyst bed is arranged in two directions along the flow direction of the reactants.
divided into two parts. The first portion, the inlet side of the reactor, comprises about 45% to about 75% of the total length of the catalyst bed.
Preferably accounts for about 55 to about 65% and about 4.5
from about 12.5 to about 12.5, preferably from about 5 to 8, more preferably from about 5.5 to about 6.5% (by weight) cupric chloride and from about 1.5 to about 7, preferably from about 2 to about 4 , more preferably about 2.7 to 3.3% (by weight) potassium chloride, with a weight ratio of cupric chloride to potassium chloride of about 1.5:1 to about 4:1, preferably about 1.5:1 to about 3:1, more preferably about 2:1 catalyst. The second portion of the catalyst bed, the outlet side of the reactor, accounts for about 25 to about 55%, preferably about 35 to about 45%, of the total length of the catalyst bed, and comprises about 12 to about 25% of the total length of the catalyst bed.
, preferably about 15 to about 20% (by weight) cupric chloride and about 0.5 to about 4, preferably about 1.5 to 3%
(by weight) of potassium chloride, the weight ratio of cupric chloride to potassium chloride being about 5:1 to about 15:1, preferably about 5:1 to about 12:1, more preferably about 10
Contains a catalyst that is 1:1. That is, the catalyst bed 12 of reactor R1 contains two types of catalysts, the first catalyst being in the inlet side of the catalyst bed to prevent the reaction from becoming uncontrollable in its early stages. the second catalyst has a higher cupric chloride content than the first in its outlet portion;
Therefore, the activity is higher and the reaction continues until the reaction stops due to oxygen consumption.

Reactor R2 contains a catalyst bed 14, which is also divided into two parts.

The first part is the inlet side of the reactor and accounts for about 45 to about 75%, preferably about 55 to 65% of the total bed length, and the second part is the outlet side and accounts for about 45 to about 75% of the total bed length. Approximately 25
It accounts for from about 55%, preferably from about 35 to about 45%. The catalyst in the first part of the bed 14 in reactor R2 is somewhat more powerful or Can be more active. The catalyst in the first portion of the bed in reactor R2 is about 5.5 to about 15%, preferably about 7.5 to about 12.5%, more preferably about 9 to 11% (by weight) cupric chloride. and about 1 to about 5, preferably about 1.5 to 3.5, more preferably about 2.5
from about 3.5% (by weight) of potassium chloride, the weight ratio of cupric chloride to potassium chloride being from about 2:1 to about 6:1, preferably from about 3:1 to about 4:1; More preferably, the ratio is about 10:3 (3.3:1). Similar to reactor R1, the second portion of the catalyst bed in reactor R2 contains a more powerful catalyst, which is about 12 to about 25
Preferably about 15 to about 20% (by weight) cupric chloride and about 0.5 to about 4, preferably about 1.5 to about 3%
(by weight) of potassium chloride, the weight ratio of cupric chloride to potassium chloride being about 5:1 to about 15:1, preferably about 5:1 to about 12:1, more preferably about 10
Consists of 1 to 1. As in reactor R1, as the gas passes through the catalyst bed, oxygen is consumed and the intensity of the reaction is reduced, so there is a risk of undesirably high localized temperatures near the outlet of the catalyst bed. is gradually lower than that near the entrance. A more active catalyst can therefore, and indeed should, be used in the outlet section for better conversion. In both reactors R1 and R2, the weight ratio of cupric chloride to potassium chloride is preferably higher in the first part of the catalyst bed than in the second part.

Once in reactor R3, almost all the remainder of the reaction has proceeded to completion and there is less and less possibility of undesirably high localized temperatures compared to reactors R1 and R2.

Thus, the entire bed of reactor R3 can be comprised of a more active catalyst than that utilized in the later portions of beds 12 and 14, which ranges from about 12 to about 25, preferably from about 15 to about 20% (by weight) cupric chloride and about 0
．． 5 to about 4, preferably about 1.5 to about 3% (by weight) of potassium chloride, and the weight ratio of cupric chloride to potassium chloride is about 5:1 to about 15:1, preferably about 5:1. 1 to 12:1, more preferably about 10:1. Also, the catalyst beds 12, 16 in the parts closest to the outlet of reactor R3 and/or reactors R1 and R2 have a lower potassium chloride content and a higher weight ratio of cupric chloride to potassium chloride. It is also possible to use catalysts. In operating the method according to the invention, hydrogen chloride gas is supplied through line 1 and
It is preheated by a preheater 22.

Ethylene is fed in line 2, preheated in preheater 21, and mixed in line 1 with the hydrogen chloride feed.
The oxygen-containing gas may be air, molecular oxygen or oxygen-enriched air, which is supplied through line 3, which is split into lines 3a, 3b and 3c, respectively. This division may be equal or unequal. The portion in line 3a is mixed with the hydrogen chloride/ethylene mixed feed in line 1 and fed through line 4 into reactor R1. The temperature of the mixed gas feed is generally about 120-220°C, preferably about 135-1
The temperature is 80°C. The mixed feed passes through a catalyst bed 12, preferably consisting of tube packed catalyst, as described above, and is removed from the reactor in line 5.
The product of reactor R1 is passed through line 5, mixed with a second portion of oxygen-containing gas in line 3b, fed via line 6 to reactor R2, and contacted with the catalyst in bed 14. .

Reaction products are removed through line 7 and line 3c
is contacted with a third portion of oxygen-containing gas at and fed through line 8 to the catalyst bed 16 of reactor R3.
The reaction product is removed in line 9, preferably cooled in heat exchanger 23, and condensed in product condenser 24. The reaction product is recovered in line 10 and consists primarily of 1,2-dichloroethane with small amounts of ethyl chloride and other chlorinated hydrocarbons. Generally, the method operates at a total system pressure of about 30 to about 100 psig, preferably about 40 to about 9 psig.
Performed at 0 psig. Reactors Rl, R2 and R
In order to maintain temperature control during 3, these reactors were
Boiling water, steam or Dowtherm (registered trademark: Dowth)
Preferably, the reactor is constructed as a jacketed reactor, such as a tube or catalyst bed covered with a jacket containing a heat exchange fluid, such as an erm) fluid. Generally, the reaction is conducted at a temperature of about 180 to about 340°C, preferably below about 300°C. In reactor R1, the hot spot temperature is generally below about 330°C, preferably about 30°C.
Maintained below 0°C. In reactor R2, the hot spot temperature is generally below 330°C, preferably below 330°C.
The temperature is maintained below 00°C. The hot spot (high temperature point) in reactor R3 is generally below 320°C.
Preferably, the temperature is maintained at 300°C or lower. Another important factor is the suppression of hot spot localization in the reactor. In each reactor, the hot spot should be localized towards the inlet end of the catalyst bed. In reactors R1 and R2, the hot spot should actually be localized on the inlet side of the first, ie less active, part of the bed. If the hot spots occur on the exit side of the bed that are far apart, this is an indication that the reaction in the bed is proceeding too slowly, i.e., the catalyst is not being utilized efficiently. . Additionally, if a hot spot occurs too close to the exit side of the bed, this will have a cumulative effect with the reaction enhancement effect of the more powerful catalyst in the second part of the bed, leading to undesirable high temperature levels there. will be reached. The division of the oxygen-containing gas into lines 3a, 3b and 3c is such that an equal amount is fed to all three reactors or, as desired, the amount fed to each reactor is determined in this art. It is done to change as is known.

Variations in the amount of gas supplied to each reactor affect the temperature within the reactor as well as the localization of hot spots. For illustrative purposes, the drawing depicts a system in which all three reactors are co-flow, ie, reaction liquid is fed from the top of the reactor and product is removed from the bottom.

However, the present invention can be carried out in either a downflow reactor or a counterflow reactor, in which case a suitable catalyst retention device used in counterflow reactors is installed. Furthermore, if the reactor is configured to alternate between a forward flow type and a reverse flow type, piping costs will be reduced. That is, reactors RO and R
It is also possible to make 3 a counter-flow type and reactor R2 a down-flow type, or, conversely, to make reactors R1 and R3 a down-flow type and reactor R2 a counter-flow type. The hydrogen chloride feed does not have to be fed entirely to the first reactor; a portion can also be fed in portions and together with the second portion of oxygen-containing gas to reactor R2.

Generally, the process is carried out using an excess of both an oxygen-containing gas and ethylene relative to the hydrogen chloride to convert the hydrogen chloride as completely as possible.

When using air, it is desirable to minimize the excess amount of these reactants to avoid handling large amounts of gas. In such cases, the excess amount of ethylene is maintained at a maximum of about 35%, preferably from about 5 to about 20%;
and the excess amount of air is up to about 25%, preferably about 5%.
It is preferable to maintain the ratio between about 20% and about 20%. Although the invention will be described herein primarily in the context of oxychlorination processes in which the oxygen-containing gas is air, the catalysts, systems and methods described herein may also contain molecular oxygen, or oxygen-enriched air. It is also suitable for application in operations when used.

In such processes, such as those described in U.S. Pat. No. 3,892,816, a large excess of Ethylene is used. This excess ethylene is preferably recovered from the reaction product and recycled to the oxychlorination reactor. That is, such methods do not aim to minimize the amount of excess ethylene. if,
When steel equipment is used in hydrogen chloride flow circuits,
A small amount of ferric chloride is produced and passes into the catalyst with the feed stream. If the oxygen-containing gas supply system corrodes, iron oxides are produced, which react with hydrogen chloride in the reactor and are converted to ferric chloride ZZ.

The catalyst also contains a small amount of iron as an impurity. However, it has been found that the addition of even small amounts of ferric chloride tends to contaminate the cupric chloride oxychlorination catalyst and render it inactive. Accordingly, one embodiment of the present invention is disclosed in U.S. Patent Application No. 595,464 (assigned by Ramsey G.Campbel).
l) As stated in the title of the invention "Purification of Gas Streams Containing Ferric Chloride" Filing date: July 14, 1975]
The ferric chloride contamination of the catalyst is transferred to a bed of activated alumina impregnated with about 5% to about 25%, preferably about 10% to about 20% (by weight) of sodium chloride or potassium chloride with a hydrogen chloride stream or mixed gas feed stream. Avoid by passing. This bed can be installed in the hydrogen chloride line 1 either before or after the preheater 22 or in the mixing feed line 4. In another scheme, it is reactor R1
It can also be located in the space 30 adjacent to the entrance of the interior. In a preferred embodiment, a tubular reactor is used and the bed material is loaded into the section of the tube of reactor R1 adjacent to the inlet, along the flow direction of the reactants and before the cupric chloride catalyst. Alternatively, the ferric chloride separated and removed from the catalyst can be prevented from migrating into the cupric chloride catalyst using a screen or the like. In a preferred embodiment, the alumina utilized is the same as that utilized as the catalyst support. Each reactor R1 and R2
The operations of are mutual operations. It should be noted that this is only partially affected.

That is, for example, if the hot spot localization or temperature in either reactor R1 and R2 is temporarily outside the desired range, the operation of the other reactor will not necessarily be adversely affected, or However, such adverse effects, if any, can be suppressed separately by adjusting the temperature of the coolant, the division of air into the reactor, etc. Similarly, although less preferred, it is possible to apply the catalyst bed split proportions and 'catalysts disclosed herein to one of the reactors R1 or R2, while the other is less efficient. It is also possible to use catalysts. Although such a configuration cannot be expected to have all of the advantages of this invention in terms of yield, pressure drop, conversion selectivity, etc., it is necessary in emergencies or when catalyst is temporarily unavailable. The following examples are presented to further illustrate various aspects and improvements of the invention, but are not intended to limit the invention in any way, but are merely illustrative of the invention.

Catalyst Preparation Examples The catalysts utilized in the following examples were prepared as follows.

Spherical alumina particles impregnated with dry powder were placed in a beaker and weighed.

The alumina used was HSCll4 described above and had the following properties. The X-ray diffraction data showed three main peaks at 1.39, 1.98 and 2.34λ, of which the peaks at 1.39 and 1.98λ were diffuse peaks.

The X-ray diffraction pattern of gamma-alumina had a main peak at the same value as shown in ASTM file 10425. However, ASTM file 1042
Although 5 has peaks with approximately equal intensities at 1.39 and 1.98λ, in the diffraction data of the catalysts used in these examples, the intensity of the peak at 1.39λ is 1.9.
It was shown to be about twice that of the 8λ peak.
These results indicate that the support is made of (crystalline) gamma-alumina as well as amorphous forms of alumina.

The amorphous one is probably rhoalumina, and its X-line diffraction pattern has a single broad band at 1.40λ~
・Ru. The microstructure of this catalyst was further investigated by etching with HF. Samples of fresh and used catalyst were placed on special sample holders and embedded in epoxide resin. The samples were cut, polished and 20% H
The sections were chemically etched for 2-5 minutes at room temperature using F solution. After 20 seconds and 4 minutes at 21X and after 5 minutes at 85
No evidence of crystal boundaries was observed.

Furthermore, no crystal boundaries were observed even after 12 minutes had passed after etching. A small amount of water was added to the beaker and the contents were stirred after each addition until moisture was observed in the beaker.

At this point, the alumina is saturated with water. The weight percentage of water absorbed was determined from the final weight of the beaker.
That is, the amount of water is determined by measuring the weight absorbed by a specific weight of base. The amount of dry alumina base to be impregnated was weighed.

The desired weight percent amounts of cupric chloride and potassium chloride based on the dry base were weighed and dissolved in water.
More water was added to the resulting aqueous solution to increase its volume to a predetermined base absorption capacity. It is then necessary to reduce this volume by about 3% to avoid a large excess of impregnating solution that is not absorbed by the base. The base and impregnating solution were placed in a coated drum, sealed, and rotated to impregnate for 15 minutes. After 15 minutes, the drum was removed, immediately opened, and placed in a glass or ceramic toilet approximately 3 inches thick.

The toilet was placed in a forced draft oven maintained at a temperature of 140°C for 16 to 24 hours. The resulting catalyst was then removed, cooled, and stored in an airtight container. The weight percentage of salts in the catalyst thus obtained was within 0.5% of the desired value. Its accuracy can be increased by completely drying the alumina base before weighing. In this case, it should be impregnated immediately after drying. Otherwise, the delay is unfavorable to the physical structure of the resulting catalyst. The experimental data in the table below were obtained using the catalyst obtained by the above process in an apparatus arranged in the flow sequence shown in the drawing.

The three reactors Rl, R2 and R3 each have a length of 12,5
The foot consisted of 1 inch diameter 40 nickel pipe, jacketed the entire length with 2.5 inch 40 steel pipe, and installed to allow the reaction reagents to flow downward.

The reaction heat is Dowtherm (registered trademark: Dowtherm)
E was removed by refluxing it in a circular space created between two pipes. The hot spot temperature in the catalyst bed of each reactor and its localization are determined by the length 12
Measured by a moving thermocouple in a foot thermowell. Hydrogen chloride is supplied to the system in line 1 through preheater 22, as shown in the drawing.

Ethylene is fed into the system in line 2 through preheater 21. Air is charged into line 3 and then split into branch lines 3a, 3b and 3c, the air in line 3a is fed into reactor R1, the air in line 3b is fed into reactor R2 and the air in line 3c is fed into reactor R3. Ta. The mixed feed to reactor R1 after preheating was at a temperature of about 140°C. 100% production (Throughout: Through-
(Put) standard is hydrogen chloride mass velocity in the reactor 117.6
It was recognized as equivalent to 7m01e/h-1n2.

Air and ethylene feed proportions were expressed as percent excess over hydrogen chloride, assuming that the reaction occurred in chemical equivalents and 1,2-dichloroethane was produced. The gas withdrawn from reactor R3, after pressure reduction, is cooled in a glass water-cooled condenser, where it removes all the unreacted hydrogen chloride as water phase and the produced 1.2
- Most of the dichloroethane is relatively pure (approximately 98.5
%) was condensed as an organic phase.

Hydrogen chloride conversion involves titrating the aqueous phase with sodium hydroxide;
The hydrogen chloride concentration was determined by obtaining the weight percent. Uncondensed gas from the water-cooled condenser was analyzed by gas chromatography.

This analysis was used to calculate the amount of ethylene oxidation and the amount of ethyl chloride produced, both expressed as a percentage of ethylene feed. Table 1 shows the conditions of an example of the method of the preferred embodiment of this invention.

This experiment lasted a total of 320 hours and was divided into two parts. The first portion occupies the first 298 hours, and the equipment is filled with 125
% output (throughput). During the last 22 hours, the equipment was operated at 100% production rate. The catalyst used was prepared in three formulations. These are listed in Table 1 as Catalyst A. Shown as B and C. The desired weight percentages of cupric chloride and potassium chloride are as follows: Table 1 shows the component amounts after catalyst analysis.

The amounts of cupric chloride and potassium chloride in Catalyst C 5 varied somewhat because catalysts obtained by several different preparations were used. The length of the catalyst bed in all three reactors is 1
35 inches, the first (upper) part is 81 inches (60% of the floor length) and the second (upper) part is 81 inches (60% of the floor length).
The length of the lower section was 54 inches (40% of the total floor length).

The first part of bed 12 of reactor R1 contains catalyst A, the first part of bed 14 of reactor R2 contains catalyst B, and the lower part of reactor R3 and reactors Rl, R2. Catalyst C was used for part 5. Various sources of unstable data were corrected and stabilized during the first 60 hours of the experiment.

Similarly, between 265 and 298 hours during the entire run, the pilot plant was shut down for one month to allow for stabilization. As can be seen from the table below, during the operation, the overall system pressure, the excess amount of air and ethylene, and the amount of air to the three reactors were varied and these conditions were used for hydrogen chloride conversion, 1,2-dichloroethane - effects on selectivity and hot spot temperature and localization were determined.

Experimental data and results are shown in the table below. Similar to Example 1 above, Examples 2 to 9 shown in the following table were conducted using various combinations of catalyst compositions and reaction conditions within the scope of the present invention.

Similar to Example 1, the length of the catalyst bed in all cases was 135 inches, and the length of the first zone, i.e., the upper inlet side, was 81*3 inches (60% of the total bed length).
and the length of the second zone is 54 inches, which is 40% of the total bed length. The catalyst in reactor R3 was Example 1.
The same is true for . Coolant temperature was maintained as in Example 1. In Examples 1-9 above, it has been found that when the catalyst is used under the conditions described, hot spot temperatures can generally be maintained below about 340 DEG C. at a throughput of 125% of the design throughput.

The hot spot also remains suppressably localized and, as is evident in practice, has in many cases fallen to temperatures well below 300°C. Equally important, the pressure drop is held substantially constant throughout the reaction system;
This is true even if the operating time in Example 1 exceeds 300 hours. That is, it was not necessary to reduce the pressure to suppress hot spots, and the pressure drop due to catalyst deterioration did not increase even during long operating hours. Furthermore, even when operating at high throughput, the ethylene excess could be maintained within a reasonable range without substantially affecting hydrogen chloride conversion. As is clear from the data in Section 1 and Table 1, it was possible to operate with an excess amount of ethylene of about 10% while still obtaining a hydrogen chloride conversion rate of 99% or more. Furthermore, the catalysts described herein have been found to be suitable even when operating below design production. That is, the catalysts and systems described herein are diverse and can range from substantially below design capacity to substantially above design capacity, depending on conditions such as feedstock supply and market demand. It can be used in plant operations where throughput can be varied without requiring conversion or modification.

[Brief explanation of drawings]

The figure is a flow sheet showing a reaction system for carrying out the method of this invention. Rl, R2, R3... Reactor, 12, 13, 1
4...Catalyst bed.

Claims (1)

[Scope of Claims] 1. A fixed-bed oxychlorination process for ethylene, comprising (
a) a first portion of ethylene, hydrogen chloride and oxygen-containing gas in a first reaction zone substantially undiluted by catalytically inert particles and cupric chloride and Potassium chloride is reacted in contact with a first catalyst bed consisting of activated alumina spherical particles, said first catalyst bed having two parts in the flow direction of the reaction reagents. a first portion comprising about 45% to about 75% of the catalyst bed and a second portion comprising about 25% to about 55% of the catalyst bed.
and the first portion contains about 4.5 cupric chloride.
% to about 12.5% (by weight) and about 1% potassium chloride
．． 5% to about 7% (by weight), the ratio by weight of cupric chloride to potassium chloride being between about 1.5 to 1 and about 4 to 1; contains about 12% to about 25% (by weight) of cupric chloride and about 0.0% (by weight) of potassium chloride.
5 to about 4% (by weight), and the ratio by weight of cupric chloride to potassium chloride is between about 5 to 1 and about 15 to 1; ) and a second portion of oxygen-containing gas in a second reaction zone substantially undiluted by the catalytically inert particles and cupric chloride. and potassium chloride supported on spherical particles of activated alumina to react.
The second catalyst bed is divided into two parts in the direction of flow of the reactants, the first part comprising about 45% to about 75% of the catalyst bed, and the second part comprising about 45% to about 75% of the catalyst bed. about 25% to about 55% of the catalyst bed, with the first portion of the catalyst bed consisting of about 5.5 to about 15% (by weight) cupric chloride and about 1 to about 5% (by weight) potassium chloride. , the weight ratio of cupric chloride to potassium chloride is about 2:1 to about 6:1, and the second portion is about 12 to about 25% (by weight) of cupric chloride and about 0.5 to about 4
% (by weight) of potassium chloride, the weight ratio of cupric chloride to potassium chloride being from about 5:1 to about 15:1, and (c) the product of step (b) above and oxygen. a third portion of the containing gas in a third reaction zone substantially undiluted by the catalytically inert particles, and cupric chloride is added to the spherical particles of activated alumina. from about 12 to about 25% (by weight) and from about 0.5 to about 4% (by weight) potassium chloride and in a ratio by weight of cupric chloride to potassium chloride of about 5:1 to about 15:1. A fixed bed oxychlor process for ethylene, characterized in that the reaction is carried out in contact with a third bed of supported catalyst. 2. The method of item 1 above, wherein the oxygen-containing gas is air. 3. The method of item 1 or 2 above, wherein the oxygen-containing gas is oxygen. 4. The first portion of the first catalyst bed comprises about 55% to about 65% of the bed, and the second portion of the first catalyst bed comprises about 35% to about 45% of the bed. ~Methods in each section of Section 3. 5. The method of paragraphs 1-4, wherein the first portion of the first catalyst bed comprises about 5 to about 8% (by weight) cupric chloride and about 2 to about 4% (by weight) potassium chloride. 6 The first portion of the first catalyst bed is about 5.5 to about 6
．． 5% (by weight) cupric chloride and about 2.7 to about 3.
The method according to each of the above items 1 to 5, comprising 3% (by weight) of potassium chloride. 7. Said first to third catalyst bed wherein the weight ratio of cupric chloride to potassium chloride in the first portion of the first catalyst bed is about 2:1.
Methods for each section in Section 6. 8 The second portion of the first catalyst bed is about 15 to about 20
% (by weight) of cupric chloride and about 1.5 to about 3% (by weight) of potassium chloride, in a weight ratio of cupric chloride to potassium chloride of about 5:1 to about 12:1. A method according to any of the above items 1 to 7. 9 said first catalyst bed wherein the weight ratio of cupric chloride to potassium chloride in the second portion of the first catalyst bed is about 10:1;
- Methods in each section of Section 8. 10. The method of each of paragraphs 1-9, wherein the first portion of the second catalyst bed comprises about 55% to about 65% of the bed. 11 The first portion of the second catalyst bed comprises about 7.5 to about 12.5% (by weight) cupric chloride and about 1.5 to about 3.5% (by weight) potassium chloride. , the weight ratio of cupric chloride to potassium chloride is about 3:1 to about 4:1
The method according to each of the above items 1 to 10. 12 The first portion of the second catalyst bed is about 9 to about 11
% (by weight) of cupric chloride and about 2.5 to about 3.5%
(by weight) of potassium chloride. 13. The method of each of paragraphs 1 to 12 above, wherein the weight ratio of cupric chloride to potassium chloride in the first portion of the second catalyst bed is about 10 to 3. 14 The second portion of the second catalyst bed is about 15 to about 2
0% (by weight) cupric chloride and about 1.5 to about 3% (by weight)
14. The method of any of the preceding paragraphs 1 to 13, wherein the weight ratio of cupric chloride to potassium chloride is from about 5:1 to about 12:1. 15. The method of each of paragraphs 1 to 14 above, wherein the weight ratio of cupric chloride to potassium chloride in the second portion of the second catalyst bed is about 10 to 1. 16 The third catalyst bed is comprised of about 15 to 20% (by weight) cupric chloride and about 1.5 to about 3% (by weight) potassium chloride, the cupric chloride and potassium chloride by weight 16. The method of each of the above items 1 to 15, wherein the ratio is from 5:1 to about 12:1. 17. The method of each of paragraphs 1 to 16 above, wherein the weight ratio of cupric chloride to potassium chloride in the third catalyst bed is about 10:1. 18 said first step comprising supplying substantially equal amounts of oxygen-containing gas to the first, second and third reaction zones;
〜17 Methods for each item. 19. The reaction zone consists of tubular reactors, each of which contains a catalyst bed within the tube.
Methods for each section in Section 8. 20. The method of each of paragraphs 1 to 19, comprising contacting hydrogen chloride with a bed of activated alumina spherical particles impregnated with sodium chloride or potassium chloride before contacting the first catalyst bed. 21 Activated alumina spheres impregnated with sodium chloride or potassium chloride before mixing the ethylene, hydrogen chloride and a first portion of the oxygen-containing gas and contacting the mixed feed with the first catalyst bed. 21. The method of any of the preceding paragraphs 1 to 20, comprising contacting a bed of particles. 22. The method of each of the above items 1 to 21, which comprises impregnating activated alumina with potassium chloride. 23 The first reaction zone is a tubular reactor, which is a packed tube containing a first catalyst bed, and the section of the tube adjacent to the inlet side is made of activated alumina impregnated with said reagent. The method according to each of the above items 1 to 22, comprising spherical particles. 24. The method of each of paragraphs 1 to 23 above, wherein ethylene is present in a molar excess of about 35% or less relative to hydrogen chloride. 25. The method of each of paragraphs 1 to 24 above, wherein the oxygen-containing gas is present in a molar excess of about 25% or less relative to hydrogen chloride. 26. The method of each of paragraphs 1 to 25 above, comprising bypassing a portion of the hydrogen chloride through the first reaction zone and feeding it into the second reaction zone. 27 Catalyst bed consisting of ethylene with hydrogen chloride and oxygen-containing gas and cupric chloride and potassium chloride supported on spherical particles of activated alumina substantially undiluted by catalytically inert particles A reaction system for fixed bed oxychlorination in the presence of (a) a first reaction zone divided into two parts along the flow direction of the reactants, the first part being Approximately 45% of the catalyst bed
% to about 75%, the second portion comprising about 25% to about 55% of the catalyst bed, and the first portion comprising about 4.5% to about 12.5% (by weight) ) of cupric chloride and about 1.5% to about 7% (by weight) potassium chloride, with a weight ratio of cupric chloride to potassium chloride of about 1.5:1 to about 4:1. and the second portion is comprised of about 12 to about 25% (by weight) cupric chloride and about 0.5 to about 4% (by weight) potassium chloride; the weight ratio of cupric chloride to potassium chloride is between about 5:1 and about 15:1; (b) the second reaction zone is divided into two portions along the direction of the reaction reagents; wherein the first portion comprises about 45% to about 75% of the catalyst bed, and the second portion comprises about 25% to about 55% of the catalyst bed, and the second portion comprises about 25% to about 55% of the catalyst bed. The first portion is about 5.5 to about 15% (by weight) cupric chloride and about 1 to 5% (by weight) potassium chloride, the weight ratio of cupric chloride to potassium chloride being between about 2:1 and about 6:1, and the second portion is about 12 to about 25% (by weight) cupric chloride and about 0.5 to about 4% (by weight). of potassium chloride, and the weight ratio of cupric chloride to potassium chloride is approximately 5.
and (c) the third reaction zone comprises about 12 to about 25% (by weight) cupric chloride and about 0.5 to about 4% (by weight) (by weight) of potassium chloride, the weight ratio of cupric chloride to potassium chloride being between about 5 to 1 and about 15 to 1;
A reaction system for fixed-bed oxychlorination of ethylene, characterized in that it consists of a second catalyst bed. 28 The first portion of the first catalyst bed comprises about 55% to about 65% of the bed, and the second portion of the bed comprises about 35% to about 45% of the bed. Section reaction system. 29 The first portion of the first catalyst bed is about 5% to about 8%
29. The reaction system of paragraph 27 or paragraph 28, comprising cupric chloride (by weight) and about 2 to about 4% (by weight) potassium chloride. 30 The first component of the first catalyst bed contains about 5.5 to about 6.5% (by weight) cupric chloride and about 2.7 to about 3% (by weight) cupric chloride.
．． Said No. 27-2 consisting of 3% (by weight) potassium chloride
Reaction system for each section in 9 sections. 31 said second catalyst bed wherein the weight ratio of cupric chloride to potassium chloride in the first portion of the first catalyst bed is about 2:1;
Reaction systems for each item in items 7 to 30. 32 The second portion of the first catalyst bed is about 15 to about 2
0% (by weight) cupric chloride and about 1.5 to about 3% (by weight)
32. The reaction system of any of paragraphs 2T to 31 above, wherein the reaction system comprises potassium chloride (by weight), wherein the weight ratio of cupric chloride to potassium chloride is from about 5:1 to about 12:1. 33. The reaction system of each of paragraphs 27-32 above, wherein the weight ratio of cupric chloride to potassium chloride in the second portion of the first catalyst bed is about 10 to 1. 34. The reaction system of each of paragraphs 27-33, wherein the first portion of the second catalyst bed comprises about 55% to about 65% of the bed. 35 The first portion of the second catalyst bed comprises about 7.5 to about 12.5% (by weight) cupric chloride and about 1.5 to about 3.5% (by weight) potassium chloride. , the weight ratio of cupric chloride to potassium chloride is about 3:1 to about 4:1
The reaction system according to each of Items 2T to 34 above. 36 The first portion of the second catalyst bed is about 9 to about 11
% (by weight) of cupric chloride and about 2.5 to about 3.5%
(by weight) of potassium chloride. 37. The reaction system of each of paragraphs 27-36 above, wherein the weight ratio of cupric chloride to potassium chloride in the first portion of the second catalyst bed is about 10 to 3. 38 The second portion of the second catalyst bed is about 15 to about 2
0% (by weight) cupric chloride and about 1.5 to about 3% (by weight)
38. The reaction system of any of the preceding paragraphs 27 to 37, wherein the reaction system comprises potassium chloride (by weight), wherein the weight ratio of cupric chloride to potassium chloride is from about 5:1 to about 12:1. 39. The reaction system of paragraphs 27-38, wherein the weight ratio of cupric chloride to potassium chloride in the second portion of the second catalyst bed is about 10 to 1. 40 Third catalyst bed is about 15 to about 20% (by weight)
of cupric chloride and about 1.5 to about 3% (by weight) potassium chloride, the weight ratio of cupric chloride to potassium chloride being about 5:1 to about 12:1. ~3
Reaction system for each section in 9 sections. 41. The reaction system according to any one of Items 27 to 40 above, wherein the weight ratio of cupric chloride to potassium chloride in the third catalyst bed is about 10:1. 42. The reaction system according to each of the above items 27 to 41, further comprising means for dividing the oxygen-containing gas into three parts, and supplying each proportion to each of the first, second and third reaction zones. 43. The reaction system according to any of the preceding paragraphs 27 to 42, wherein the reaction zone consists of a tubular reactor, each tube containing a respective catalyst bed. 44 The reaction system according to any of the above items 27 to 43, in which spherical particles of alumina impregnated with sodium chloride or potassium chloride are further contained in the tube of the first reaction zone adjacent to the inlet side in front of the catalyst bed. A reaction system consisting of a reaction reagent placed in the direction of flow. 45. The reaction system according to any of the above items 27 to 44, wherein alumina is impregnated with potassium chloride. 46 From contacting ethylene, hydrogen chloride and oxygen-containing gases with a catalyst bed that is catalytically undiluted and in which cupric chloride and potassium chloride are supported on activated spherical particles of alumina. A process for oxychlorination of ethylene in a fixed bed multistage reaction system comprising: in at least one reactor, the catalyst bed is divided into two parts in the flow direction of the reaction reagents, the first part being the second portion comprises about 25% to about 55% of the catalyst bed, and the first portion comprises about 4.5% to about 4.5% cupric chloride. Approximately 12.5
% (by weight) and potassium chloride from about 1.5% to about 7%
(by weight), the weight ratio of cupric chloride to potassium chloride being between about 1.5 to 1 and about 4 to 1;
and the second portion is about 12 to about 25% cupric chloride.
(by weight) and potassium chloride from about 0.5 to about 4% (by weight), the ratio by weight of cupric chloride to potassium chloride being between about 5:1 and about 15:1. A fixed bed oxychlorination process for ethylene, characterized in that: 47 The first portion of the catalyst bed comprises from about 4 to about 8% (by weight) cupric chloride and from about 2 to about 4% (by weight) potassium chloride, the cupric chloride and potassium chloride weighing 47. The method of paragraph 46, wherein the ratio is about 1.5:1 to 3:1. 48 A raw material feed consisting of ethylene or a partially chlorinated derivative thereof, hydrogen chloride and an oxygen-containing gas, catalytically undiluted and cupric chloride and potassium chloride activated alumina A process for the oxychlorination of said feed in a fixed bed multistage reaction system comprising contacting the feed with a bed of catalyst supported on spherical particles, the catalyst bed being in the flow direction of the reactants in at least one reactor. the first portion comprising about 45% to about 75% of the catalyst bed, and the second portion comprising about 25% to about 55% of the catalyst bed; The first part contains about 5.5 to about 1 cupric chloride.
5% (by weight) and potassium chloride from about 1 to about 5% (by weight), the ratio of cupric chloride to potassium chloride being between about 2:1 and about 6:1 by weight. ,and,
The second portion is about 12 to about 25% (by weight) cupric chloride.
and about 0.5 to about 4% (by weight) of potassium chloride, wherein the ratio by weight of cupric chloride to potassium chloride is between about 5 to 1 and about 15 to 1. oxychlorination method. 49 The first portion of the catalyst bed is about 7.5% to about 12.5%
(by weight) of cupric chloride and from about 1.5 to about 3.5% (by weight)
49. The method of claim 48, wherein the cupric chloride to potassium chloride weight ratio is from about 3 to 1 to about 4 to 1. 50 A catalyst composition consisting of cupric chloride and potassium chloride supported on a base consisting of spherical particles of activated alumina, the base comprising about 225 to about 275 m^2/
g BET surface area, at least 90% frictional strength, about 0
．． 3 to 0.6 cc/g total nitrogen pore volume, about 50 to 1
A catalyst composition having an average pore diameter of 00 Å and about 20 to about 50% of the pore volume being constituted by pores having a diameter of about 80 to about 600 Å.