CA1154463A - Reactor for oxychlorination of ethylene and process therefor - Google Patents

Abstract

" IMPROVED REACTOR FOR OXYCHLORINATION OF ETHYLENE AND
PROCESS THEREFOR"

ABSTRACT OF THE DISCLOSURE

The present invention refers to an improved reactor for oxychlorination of ethylene and to the process used therefor, which in a general way proceeds in accordance with the following reaction:

Description

~ACKGROUND OF THE INVENTION

The invention is related to an ethylene oxychlorination process in the presencè of a catalyst the efficiency of which is remarkably improved by the use of an especially designed reactor which maintains a fluid catalytic bed in the reactor tubes by the use of a cap ferrule and a fixed bed of granulated nickel.
Most of the known processes for halogenation of aliphatic hydrocarbons and in particular to obtain 1,2-dichloroethane are generally carried out through direct chlorination of ethylene or through oxychlorination of ethylene.
The direct chlorination of ethylene to produce 1,2-dichloro ethane is conducted in a liquid phase reactor by mixinq intimately ethylene and chlorine in liquid dichloro ethane. In general, these reactions are conducted in the pre-sence of catalysts such as ferric chloride.
Oxychlorination of ethylene to produce 1,2-dichloro ethane is also carried out in reactors, in the presence of fluid or fixed catalytic beds, under moderate temperatures and pressures. The catalysts used in this type of reaction are in most cases copper based, such as copper chlorides and sodium or potassium chloride, deposited on an adequate support.
Other types of catalysts are also known which are constituted by rare earth metallic chlorides, sulphate salts and ferric chloride.
As for the operating conditions, it happens that at temperatures above 300C secondary reactions usually take place, deactivating the catalyst used when same undergoes a higher coking; the sublimation of copper is also undesirably increased.
The byproducts formed by secondary reactions during oxychlorination of ethylene are in general vinyl chloride, ethyl chloride, l,l-dichloro ethane, trichloroethylene, ~.
~ -2-X

~154~63 methylene chloride, etc. These by-products are formed depending on the selected process and all of them cause problems in the obtainment of 1,2-dichloro ethane.
According to the prior art, there exist at the present time several processes to obtain chlorinated hydro-carbons, such as the processes of B.F. Goodrich, PPG Industries, Inc., Rhone-Poulenc, S.A., Monsanto Co., etc.
The Goodrich process produces dichloro ethane from ethylene, chlorine and air, through the stoichiometric reaction:

C12 + C2H4 3 C2H4C12 or by means of oxychlorination of:

C H + 2HCl + 1/2 2 - > C2H4C12 2 The latter reaction is conducted in a fluid bed of a copper chloride catalyst. The reaction is carried out in a specially designed reactor made o~ carbon steel.
The PP~ Industries, Inc. process is conducted in a direct chlorination unit, combining chlorine and ethylene in a liquid phase in accordance with the reaction:

2 4 2 ~ C2H4C12 or in an ethylene oxychlorination unit in which oxygen and HCl are reacted in a vapor phase in the presence of a catalyst developed by PPG, in accordance with the reaction:
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: .
C2H4 + 2HCl + 1/2 2 Cat. ~ C2H4C12 + H20 The raw dichloro ethane of both processes is com~ined with the recycled dichloro ethane in the pyrolysis unit and is purified by distillation.

liS~463 The Rone-Poulenc, S.A. process produces dichloro ethane either by direct chlorination where chlorine is reacted with ethylene in liquid dichloro ethane in accordance with the reaction:

C2H4 ~ C12 ~ -) C2H4C12 or through oxychlorination of ethylene in accordance with the reaction:

C2H4 ~ 2HCl + 1~2 2 ~ 2 4 2 H20 The oxychlorination process is a vapor phase reaction which is conducted in a carbon steel reactor that operates under moderate pressures.

In the direct chlorination process, the ethylene and chlorine gases are loaded into the reactor which contains liquid dichloro ethane as a reaction medium and cooling system, and the dichloro ethane which is produced is treated thereafter to withdraw the chlorine and HCl content. The raw dichloro ethane is purified by distillation.

Other known techniques such as the Stauffer process produce dichloro ethane either by direct chlorination of ethylene where ethylene and chlorine are reacted in a liquid phase and under controlled reaction conditions, the obtained product is combined with the oxychlorination product, and then it is washed and distilled, or the dichloro ethane is obtained by the combination of the oxy reaction with the HCl recycle, fresh ethylene and air in a fixed catalytic tubular reactor, or else by the modified process of oxychlorination of ethylene based X
, on oxygen, where the condensed dichloro ethane is compressed and recirculated to the first oxy reactor, using an excess of ethylene to increase the HCL conversion and to decrease the formation of by-products.

Among other technologies which are known for the obtainment of dichloro ethane, there are the MTC Chemical Technology process, and the Toyo Soda Technology.

The MTC technology uses a boiling liquid process for the direct chlorination reaction where the reaction heat is dissipated with an outgoing stream of gaseous dichloro ethane which is externally condensed and sent to purification.

The MTC technology also uses the oxychlorination process, and it is characterized by the use of oxygen batches and a fluidized bed reactor, the effluent gases from the ; reactor being cooled rapidly with circulating dichloro ethane followed by a caustic neutralization.

The Toyo Soda process is similar to the one developed by the Stauffer technology, its main differences being the use of an absorber-separator on the gas effluent of vent oxy and the dehydration of the raw dichloro ethane before the purification.

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I; 1154463 Monsanto Tec~mology - This process i9 similar to the Stauffer technol~gy, and it i5 based on recirculating the HCl produced in the vinyl chloride plant to an oxychlorination reactor~
The process may be carried out in the same manner as those mentioned before, that is by direct chlorination or by oxychlo-rinati-on.

The Monsanto oxychlorination process is a vapor phase reaction and it is carried out in a carbon steel reactor which operates at moderate pressures, in the presence of a fluid bed catalyst.

' ~ 1 I The efficiency of processes that are carried out in re- ¦

1 1 actors varies depending on the design of the chosen reactor.
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Reactors may be fixed bed catalytic reactors or fluidized bed catalytic reactors; in general, it has been observed that the fluidized bed reactors provide a better ethylene conversion , (94 - 97%), of HCl (95 - 97%), and a better selectivity of 1,2 dichloro ethane (94 - 96%), than the fixed bed reactors. These 1.
i efficiency results are also subject to the type of reactor design ¦

,used and to the quality of the raw materials employed.
11 ~

I The fluidized bed oxychlorination reactors generally comprise diffusing elements for the reaction gases made of porous plates which perform an adequate distribution of the gases, such porous plates being commonly known as ferrules and constituted by a porous plate with a filtering element.

- The known reactors that operate with this type of fer-l~
~ ~ - 6 -I ` 1154463 rules present so~e disadvantages in their use due to the fact that the porous pla-te is only useful for cIean feed gases, from the known experiences in plants producing chlor~ted derivatives it is observed that the stream of anhydrous HCl which results from the pyrolysis of 1,2-dichloro ethane is not completely clean in spite of its filtration before its use; this causes in a period of 3 to 4 months of use of the porous plate ferrule a plugging of the filter as well as of the porous plate.

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¦ The plug~ing of the porous plate and the temperature difference between the operating temperature of approximately 180C and the subsequent cooling of the reactors are factors that ~- ' cause the premature breakage of the porous plate.
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The plugging of the porous plate also causes a decrease !
of the fluidification speed which results in the compression of the catalyst in the reactor tubes; this phenomenon causes the increase in the formation of secondary reactions which affect the efficiency of the process.

The applicant has developed a process to obtain l,~
chloro ethane which is more efficient, by the oxychlorination of ethylene in a tubular reactor which comprises a gas diffusor that is especially designed with a cap ferrule which is improved by the incorpora~ion of a nickel granule bed that constantly maintains a fluid catalyst during the reaction. Under these conditions, it is not necessary to make a previous purification of;
the raw materials, particularly of the HCl stream.

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There being no plugging of the ferr~le, the for~ati~n of secondary reactions created ~y the compression of thc catalyst is avoided, and consequently the efficiency of the process is considerably increased.

BRIEF SUMMARY OF THE INVENTION

The invention refers to an improved oxychlorination re-actor and to a process to obtain 1,2-dichloro ethane by the oxy-chlorination of ethylene in the presence of a fluid catalyst bed, the reaction being carried out in a specially designed carbon steel tubular reactor which comprises a diffusor for the distri-bution of gases constituted by a cap ferrule and nickel granules that permit conducting the reaction at moderate temperatures and pressures. I

It is therefore, an object of the present invention to ' provide a tubular reactor that is especially designed with a gas diffusor which is composed by the combination of a cap ferrule and a nickel granule bed.

1~ 1 Another object of the invention is to provide a reactor ' ¦ in which the process is carried out without the compression of the catalyst in the reactor tubes, by which the formation of increased heating areas in the reactor is avoided, which results in a less efficient process due to the formation of secondary reactions.

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Still another object of the present-invention is to pro-; vide a gas diffusor combined with a nickel granule bed which !

~154463 maintains constantly an ad~cluate ~luidification of the I gases while the catalytic activity of the catalyst lasts.

A further obj ect of tl-e present irlvention is to pr~>vidc a more efficient process to obtain 1,2-dichloro ethane by the oxychlorination of ethylene which maintains a catalytlc bed that is always in a fluidized condition.

Another object of the present invention is to provide a more efficient process to obtain 1,2_dichloro ethane while avoiding the formation of secondary reactions.
, BRIEF DESCRIPTION OF THE DR~WINGS

, The drawings that describe the reactor are presented with the purpose of a better illustration of the invention~

¦, Figure 1.- Figure 1 is a longitudinal section of a ver-¦, tical view of the carbon steel reactor in which the oxychlorina-i tion reaction is carried out for the obtainment of 1, 2-dichloro ethane. In this section the vertical heat exchange type tubes canl ~e observed where the fluid catalyst is located. ~-', .
Figure 2.- Figure 2 is an elevated view of the lower mirror of the reactor calender. In this view the ferrule holder cou led to the, calender tubes is observed, fixed by stud bolts.

- Figure 3.- Figure 3 is a longitudinal vertical section ' of one of the tubes of the calender of Figure 2.

- 9 _ , ~154~63 ! Figure 4.- Figure 4 i~ a v~Jtical s~ction o the lower pOltion of the tube of Figures 2 and 3, in which the ferrule, th~
ferrule holder and the nickel ~ranule bed can be observed in more detail.

~ igure 5.- Figure 5 is a vertical section of the ferrule of Figure 4, in which the ferrule cap can be seen in mor~
detail.

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¦ Figure 6.- ~igure 6 is a longitudinal cross-section of I ,the ferrule holder.
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~ igure 7.- Figure 7 is a cross-section of the check lvalve coupled to the ferrule holder of Figure 6.

1.
, DETAILED DESCRIPTION OF THE INVENTION
1~

The process of the present invention is carried out by hlorination of ethylene with anhydrous hydrochloric acid and ¦'oxygen in the presence of a fluid catalyst bed to obtain 1, 2-; ~dichloro ethane in accordance with the reaction:

C H + 2HCl + 1/2 2 170 - 1;35 C ~ 2 4 2 2 The reaction 1S carried out in a catalytic multitubular ty~e reactor which maintains a fluid catalyst bed by mean~s of the special design of a cap ferrule combined with a nickel granule bed of from 35 to 12 mesh size which in turn functions as ~; ;distributor of the reaction gases in each of the reactor tubes.
E t , - 10 -: !
:, The oxychlorination reaction o~ ~thylene is exo~hermic and the generated heat is used to produce saturated vapor, ap-prox~mately 10.5 kg/cm2 in the reactor casing, the generated vapor being used in some of the process operations. The opera-ting temperatures in the fluidized bed zone may be ~etween 190D
and 240~C.

1., ~ The catalyst used when in repose is a solid based on a ¦ mixture of copper salts and oxides or else of copper salts such as Cu chlorides supported by alumina. The catalyst deposited on ¦ the nickel granule bed inside the reactor tubes changes its state of repose to the fluid state due to the passing of gases through the ferrule and through the spaces that are free between the granulated spheres.

~.
Il, ¦ The HCl used in the oXychlorination reaction origin-ates in an HCl stream which is formed during the pyrolysis of dry 1,2-dichloro ethane in the obtainment of vinyl chloride.
! ~ i ¦l The theoretical molar relation of ethylene/anhydrous I ¦, HCl~oxygen is 1/2/0.5.
I' ,, In accordance with the different molar relations of the hydrochloric acid/Ethylene-Air loads and the feeding speeds, it is observed that the most advisable stoichiometrical molar reaction is:

Ethylene~nhy HCl/Oxygen = 1jl 7/0,57 - -since the conversion is practically constant at fluidizing speeds of 0.14 to 0.20 m~sec.

~i , The variations outside the relation Of Ethylene~Hcl/
Oxygen = 1/1.7/0.57 involve the formations of secondary reactions ¦ such as the formation of trichloro ethane accordlng to the reaction:

C2H4 + 3HC1 ~ 2 - ~ C2H3C13 + 2H20 ¦ Once the reaction is carried out, the raw gaseous 1,2-dichloro ethane formed mainly by 1,2-d`ichloro ethane, CO2 , CO and¦
¦ HCl is rapidly cooled to approximately 90~C in an HCl washer to ~, condense part of the 1,2-dichloro ethane and to eliminate the HCl;
I the gaseous product is thereafte- sent to a neutralization tower ;with NaOH, where carbonates are formed and most of the 1,2-; dichloro ethane is condensed. The mixture formed thereby is sent to a separation tank where the 1,2-dichloro ethane is separated.
.

In the following examples the different operating condi-!~ tions and process modes of oXychlorination of ethylene are il-¦ lustrated, where said process is conducted in a reactor of a cap ferrule type. Information is also provided about ~he operating conditions of a reactor in which a porous plate ferrule is employed.

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EX~MPLE No. 1 Into a multitubular reactor of a cap ferru:le and nickel granule at a temperature of about 120"C, a stream made up of 17 to 18 ~' - 12 -! ;

115~63 mole ~ of ethylene, 30 to 31 mol~ ~ of anhydrou~ HCl, and 10 to 11 mole % of 2 is fed, the reaminder belng N2, and the reactlon being j carried out at an approximate pressure of 2 kg/cm2, in the pre-sence of a fluid bed of a catalyst made of copper chloride or copper oxychloride with an alumina support of 60 to 100 mesh size;
and a-fine bed of nickel granules of from 3 to 12 mesh size. The reaction is conducted at temperatures in the range of 190 to 240C, with a relation of feed to the reactor of ethylene/hydrochloric acid/oxygen molar proportions approx~tely 1/1.7/0.57.
' .

The outcoming gases from the reactor are condensed in ¦1 a washing tower of HCl with a fast cooling to approximately 90~C, i, where HCl is eliminated without reacting. Thereafter, the raw 1,2 dichloro ethane constituted by l,2-dichloro ethane, CO and C02 is sent to a neutralization tower with 4% soda; in later stage the 1,2-dichloro ethane is stripped and the 1,2-dichloro ethane is sent to a storage tank where a purity of 98.5% of dichloro ethane is determined.

iAn evaluation of the routine day-to-day analyses of the I process is carried out during the first days of initiation of the process, and it is determined that the optimum conversion of HCl is 99.4%, and that is practically constant at fluid speeds of from 0.137 to 0.22 m/sec. The selectivity is 98.9%.

After an operation time of three months, a new evalua-, ~ion of the routine analyses of the outcoming gases from the reactor is carried out which shows the followiny values:

_ 13 -. ,,~,,~ .

. HCl conversiOn % 97 ¦~ Selectivity, ~ 98.9 . Outgoing temperature 210C

The above results indicate that the catalyst used has maintained its fluidity without compression thereof in the re-: actor tubes, in view of which the plugging problem in this fer-rule does not exist, since it continues maintaining a good pro-cess efficiency.

¦, EXAMPLE No. 2 !` i In accordance with the process of Example 1, a reactor ~ i with a temperature of about 120oc and a pressure of 2.05 kg/cm2g ; is fed with a stream made up of 28 le % of HCl, 19.5 mole % of ethylene, 11.02 le % of 2~ and the remainder of N2. The catalytic reaction is conducted at a temperature between the range of 220 - -'- 1 I
¦ 230~C and a flow speed of 0.17 to 0.18 m/sec.
,., ~ ~ 1i ¦ An evaluation of the routine analyses-is made after a ¦
period of three months and 15 days of the outcoming-gases from 11 the reactor, which shows the following results: I

% of HCl conversion 99.92 Selectivity, % 9B.8 Outcoming temperature 210~C

The above results indicate that the cat:alyst used has _ 14 -~154~63 ,n,dintained its fluidity without compres~;ic,n IhereoL in t-he rc-actor t~bes, in view of which the plugging problem in this ferrule does not exist, since it continues to maintain a good process efficiency.

EX~PLE No. 3 In accordance with the process of Example 1, a reactor with a temperature of about 120C is fed with a feed mixture which comprises from 18.5 to 18.7 mole % of ethylene, from 30.4 to ¦
30.6 mole % of anhydrous HC1 and from 10.4 to 10.7 mole ~ of 02,the remainder being N2, the feeding speed being between 0.17 and 0.18 !
'm/sec.; the catalytic reaction being conducted at temperatures ¦l in the range of 190 - 240C, and at pressures of from ~1.9 to 2 kg/cm2.

j An evaluation of the routine analyses of the outcoming ¦gases from the reactor is conducted after a period of 4 months counted from the initiation of the process, which shows the following results:

I HCl conversion % 99.57 Selectivity, % 98.8 Outgoing temperature 210~C

EX~M~LE No. 4 In accordance with the process of Example 1, a multitu-_ 15 -' I

-` 1154463 ¦ ~ular ferrule and nickel granule type of reactor at an approxi-mate temperature of 120C is fed with a fecd'mixture which comprises 20.75 mole % of ethylene, 25.88 mole % of anhydrous HCl and ll.ll mole % of 2~ the remainder being Ni, the feedlng .

speed being 0.18 m/sec., the catalytic reaction being carried out ¦ at temperatures in the range of 230 - 240C, and at . Il pressures of 2.25 to 2.30 kg/cm2.

.~ An evaluation of the routine analyses carried out daily with the outgoing reactor gases is made after a period of 4 months . after the date of initiation of the process, which shows the following results:

',' l ~;~,, I
:. HCl conversion percentage97 4 ;`. ji Selectivity, % 98.7 -!i . ~
~l Out~oing temperature 210C
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~ , EX~MPLE No. 5 I' .

A fluidized bed porous plate ferrule reactor type of sinterized "Inconel"* is fed with a mixture which comprises ethylene,j hydrochloric acid and oxygen in a molar relation of approximately ~;~ l/1.70/0.57 with an excess of ethylene to maximize the HCl conver-.. . . . .
sion and the selectivity of l,~ dichloro ethane, the reaction being carried out at a temperature of approximately 200 to 250C

; and at a pressure of 2 atmospheres abs, in the presence of a .copper chloride catalyst supported on alumina.

~he gases from l,2 ~ichloro ethane in a raw form are t ~ - 16 -~* Trademark for a nickel-based heat-resistant alloy containing 79.5% nickel, : 13% chromium, 6.5% iron, 0.08~ carbcn, and small amounts of coo~ier~ manganese znd silicon.
' ~

Il 1154463 sent to an HCl washer and ~mediately tllereafter they are trcated j ¦I with caustic soda, the product being dried and sent to a direct chlorination reactor to react the residual ethylene and to recover the 1,2-dichloro ethane.

An evaluation of the routine analyses is made after the ~ first 5 days of the process initiation, of the outcoming gases of ¦ the reactor, and the following results are determined:
I
HCl conversion % ~0 0 Selectivity, % 81.0 ¦ Outcoming temperature C 220 The obtained results which indicate a low selectivity and a low conversion are probably due to the fact that the porous plate has been plugged, as well as the ferrule holder filters. - i The fluidification speed is lower than the limit (Approx. 0.122 m/
sec.) due to the catalyst compression in the reactor tubes.

DESCRIPTION OF THE EQUIPMENT AND PROCESS IN
ACCORDANCE WITH THE DRAWINGS.

l`he equipment or apparatus which is the object of the , invention, in accordance with Figures 1 through 7, is a carbon steel tubular reactor 10 of the heat exchange type, basically constituted by a vertical tube calender 11 which are joined -together by an upper mirror 12 and a lower mirror 13, the free spaces between the tubes forming together a reactor casing 14 I which has a water feed 15 as a means for dissipating the reaction B i - 17 -, .

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heat in the lower end of a vapor outl~t 16 which is cJenerated during the Oxychlorination reaction on the opposite upper end.

he casing 14 is attached on its upper portion to a dome 17 which functions as an upper degasifying portion and in I its lower portion is joined to a lower header 1~ which operates j as a distributing chamber for the reactants feed. On the upper . ~ I end of dome 17 is located the outlet 19 for the reaction gases, ! while on header 18, on its upper middle portion, is located the inlet 20 for feeding of the reactants EICl, ethylene and air; to the sides of feeding inlet 20 are located the rupture discs 21 ~ich ¦I function as protection elements when an overpressure risk or .. ' ''................................... ' i I llmlt of explosive mixtures exist.

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Due to corrosion of the reactants, header 18 of the feeding chamber 13 is coated with a stainless steel material 22.
¦l On the inside of each of tubes 11 of the calender and on the side I
of a mirror located in the lower portion 13, there is a cap fer- i , rule 23 supported by a ferrule holder 24. Cap ferrule 23 is a diffusing element of the reaction gases which comprises a sleeve 25 made of stainless material, which is concentrically rolled to the inside of tube 11, the upper end of said sleeve 25 being welded to a plate 26 which functions as a cap ferrule that acts as a cap bubbler 27 which in turn presents a vertical orifice 28 for the admission of gases, the threaded inside of which permits the coupling of a protuberant conduit 29 to hold the cap 30 with the bubbler 27 by means of pins 31.

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The ferrule holder 24 is a metallic hexagonal plate ,~ _ 18 -.;.Ii . ' which functions as a ferrule support and present~ i.n :its center a tubular protuberance 32 threaded on its inside portion which couples a check valve 33 which has the function to act when there exists a back flow in the inside of reactor 10. ~er-rule holder 24 has a concentric recess 34 on sleeve 25 in which a packing 34 which seals hermetically the ferrule against the ferrule holder 24 by means of the tightening of the stud bolts fixed coaaxially to tube 11.

On the upper portion of ferrule 23, that is, on plate 26 is located a nickel granule bed 36; the granule spheres are distri-buted covering all the surface of plate-26 and they overflow the height of the cap bubbler 27; granule bed 36 has the function of making the gas di~fusion distributed by cap ferrule 23 more effective. , TYPICAL WORKING CONDITIONS OF TB REACTOR

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Pressures of: Operation .

Inlet 1.85 i I
Outlet 0.9 .95 Tem~eratures of: O~eration :

Inlet 120~C
Outlet 210C
Beds 180 - 235C

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, - 19 -:

115~63 IStoichiometrlc R~la ions: j ! (Reactor ~let) ~: ' i ¦ Ethylene/ HcL/oxygen 1/2/0.5 . Operatinq Relations:

I ¦! ( Inlet) HCl = 1.7 Ethylene . ¦ Oxyqen = O.355 ¦ HCl ¦~ Reactor Outlet:
.~ I
¦ HCl 0.44% mole onversion % 99.92 Test with a Sinterized"Inconel"TMorous plate ferrule ,~ i, . , l; !
A natural gas pressure is applied in the feeding header of 2.5 kg/cm2 , an equivalent natural gas flow of 0.7 feet/sec.
34% of rotameter of 22.8 m3~h) with conditions: air at 20~C
and 2 kg/cm2.

It is observed that fluidification is good and the dis- :
tribution of catalyst is also good, after which 10 g of lampblack were added to the feeding header which was brought into operation to arrive to a pressure of 2.5 kg/cm2g, after a short period it is observed that there is a plugging in the porous plate and thereafter a breakage of same.
B

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11544~i3 Test to demonstrate the efficiency of the Cap ferrule - nickel qranule:
A natural gas pressure is applied to the header that is used for feeding the reactor at 2.5 kg/cm2g with a natural gas flow of the equivalent of 0.7 ft/sec. (34~ of rotameter of 22.8 cm m~hr. with conditions at 20C in air and 2 k.g/cm2g).
It is observed that fluidification and distribution of air are good, and lOg of lampsmoke were added to the feeding header and the operation of same was started until reaching a pressure of 1.6 kg/cm2, no plugging or channeling being observed in the ferrule.

`, -20a-

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. An improved multitubular heat exchanger type reactor to carry out the oxychlorination of ethylene to obtain 1,2-dichloro ethane, which comprises a calender formed by a casing and a system of vertical tubes which are joined at one of their ends to an upper mirror and at the other end to a lower mirror; an upper dome which serves as a degasifying chamber, a lower dome or feeding header which functions as a distributing chamber for the reactants, and a diffusing element of the reaction gases coupled on the inside of the reactor tubes, characterized in that said diffusing element is constituted by a cap ferrule, a metallic granule bed and a ferrule holder attached to the lower end of the calender tubes.

An improved multitubular reactor in accordance with claim 1, characterized in that on the lower end of each of the calender tubes, on the side of the lower mirror and inside the tubes, there is located a gas diffusing element which comprises a cap ferrule attached to the calender tube, a metallic granule bed and a ferrule holder attached to the tube by joining elements.

An improved multitubular reaxtor in accordance with claim 2, characterized in that the ferrule is constituted by a metallic cylindrical sleeve attached on its upper surface to a stainless metallic cylindrical plate which presents on its center a joining tubular element on the inside of which is in turn a coupled movable tubular element to which the ferrule cap is attached by means of fastening elements.

An improved multitubular reactor in accordance with claim 3, characterized in that above the cylindrical plate of the ferrule there is located a metallic granule bed which covers and overtops the cap height, in order to increase the distri-bution area of the gases and to improve the catalyst fluidity.

An improved multitubular reactor in accordance with claim 1, characterized in that the ferrule holder is a metallic hexagonal plate which presents on its center a conduit to which is coupled a one-way valve which controls any backflow inside the reactor.

An improved multitubular reactor in accordance with claim 3, characterized in that the ferrule holder includes on its upper surface a recess for receiving the ferrule sleeve, and packing which seals the ferrule joint between the ferrule holder and the sleeve.

An improved multitubular reactor in accordance with claims 5 and 6, characterized in that the ferrule holder comprises fastening elements for attachment to the ferrule cap.

An improved multitubular reactor in accordance with claim 1, characterized in that the calender casing presents on its lower end a water feed to dissipate the reaction heat, and on its upper end an outlet for vapor generated during the reaction.

An improved multitubular reactor in accordance with

claim 1, characterized in that on the sides of the feed inlet of the reactor header there are located two rupture discs which function as safety elements when there exists an over-pressure above the working pressure of the reactor.

An improved process to obtain 1,2-dichloro ethane by oxychlorination of ethylene, which comprises reacting an HCl stream with ethylene and oxygen in a catalytic reactor, with a molar relation of ethylene/anhydrous HCl/oxygen of 0.5 to 1/1.7 to 2/0.3 to 0.7, at temperatures in the range of 190 - 240°C and at approximate pressures of 1.5 to 2.5 kg/cm2, characterized in that the catalytic reaction is carried out in a reactor which comprises a reaction gas diffusing element constituted by a cap ferrule and a metallic granule bed, on a fluid copper chloride bed or a bed made of a mixture of copper salts and oxides.

An improved process to obtain 1,2-dichloro ethane in accordance with claim 10, characterized in that from 17 to 21 mole % of ethylene, from 25 to 31 mole % of anhydrous HCl and from 10 to 11.5 mole % of O2 are reacted, at temperatures in the range of 220 - 240°C and at approximate pressures of from 1.9 to 2.2 kg/cm2 , in a catalytic reactor of the heat exchange type where the fluid speed is maintained practically constant between 0.14 m/sec . and 0.20 m/sec.

An improved multitubular heat exchanger type reactor to carry out the oxychlorination of ethylene to obtain 1,2-dichloro ethane comprising:
a calendar reactor including a casing and a system of vertical tubes, a first mirror joined to the upper ends of the vertical tubes;
a second mirror joined to the lower ends of the vertical tubes;
a degasifying chamber formed as an upper dome attached to the upper portion of the casing;
a distributing chamber for the reactants, said chamber being formed as a lower dome or feeding header attached to the lower portion of the casing;
at least one diffusing element for the reaction gases individually coupled to the inside of at least one reaction tube, wherein each said diffusing element comprises a ferrule including a metallic cylindrical ferrule sleeve, a horizontal annular stainless metallic plate attached to the upper edge of said cylindrical sleeve, a tubular element affixed to the circular inner surface of said annular plate, a movable tubular element adjustably mounted inside said tubular element, and a ferrule cap mounted on said tubular element, a holder for said ferrule attached to the lower end of the calender tubes; and a metallic granule catalyst bed located on the cylindrical plate of the ferrule.