U.S. patent application number 13/880184 was filed with the patent office on 2013-10-31 for catalyst for preparing chlorine by oxidation of hydrogen chloride and preparation thereof.
This patent application is currently assigned to NINGBO WANHUA POLYURETHANES CO., LTD.. The applicant listed for this patent is Jiansheng Ding, Weiqi Hua, Yinchuan Lou, Yi Wan, Xunkun Wu, Guangquan Yi. Invention is credited to Jiansheng Ding, Weiqi Hua, Yinchuan Lou, Yi Wan, Xunkun Wu, Guangquan Yi.
Application Number | 20130288884 13/880184 |
Document ID | / |
Family ID | 43808436 |
Filed Date | 2013-10-31 |
United States Patent
Application |
20130288884 |
Kind Code |
A1 |
Yi; Guangquan ; et
al. |
October 31, 2013 |
CATALYST FOR PREPARING CHLORINE BY OXIDATION OF HYDROGEN CHLORIDE
AND PREPARATION THEREOF
Abstract
The present invention relates to a catalyst for producing
chlorine by oxidation of hydrogen chloride and a method for
preparing the same. The catalyst comprises a support and active
ingredients that comprise 1-20 wt % of copper, 0.01-5 wt % of
boron, 0.1-10 wt % of alkali metal element(s), 0.1-15 wt % of one
or more rare earth elements, and 0-10 wt % of one or more elements
selected from magnesium, calcium, barium, manganese, iron, nickel,
cobalt, zinc, ruthenium or titanium based on the total weight of
the catalyst. The catalyst is prepared by a two-step impregnation
method. Comparing with the available catalysts of the same type,
the catalyst according to the present invention has greatly
improved conversion and stability.
Inventors: |
Yi; Guangquan; (Yantai,
CN) ; Lou; Yinchuan; (Yantai, CN) ; Wan;
Yi; (Yantai, CN) ; Wu; Xunkun; (Yantai,
CN) ; Hua; Weiqi; (Yantai, CN) ; Ding;
Jiansheng; (Yantai, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Yi; Guangquan
Lou; Yinchuan
Wan; Yi
Wu; Xunkun
Hua; Weiqi
Ding; Jiansheng |
Yantai
Yantai
Yantai
Yantai
Yantai
Yantai |
|
CN
CN
CN
CN
CN
CN |
|
|
Assignee: |
NINGBO WANHUA POLYURETHANES CO.,
LTD.
Ningbo
CN
WANHUA CHEMICAL GROUP CO., LTD.
Yantai
CN
|
Family ID: |
43808436 |
Appl. No.: |
13/880184 |
Filed: |
June 3, 2011 |
PCT Filed: |
June 3, 2011 |
PCT NO: |
PCT/CN2011/075319 |
371 Date: |
July 10, 2013 |
Current U.S.
Class: |
502/73 ; 502/202;
502/207 |
Current CPC
Class: |
C01B 7/04 20130101; B01J
37/0244 20130101; Y02P 20/20 20151101; B01J 29/146 20130101; B01J
29/16 20130101; Y02P 20/228 20151101; B01J 23/83 20130101 |
Class at
Publication: |
502/73 ; 502/202;
502/207 |
International
Class: |
B01J 29/14 20060101
B01J029/14; B01J 23/83 20060101 B01J023/83 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 18, 2010 |
CN |
201010567038.9 |
Claims
1. A catalyst for producing chlorine by oxidation of hydrogen
chloride comprising a support and active ingredients, wherein the
active ingredients comprise: 1-20 wt % of copper, 0.01-5 wt % of
boron, 0.1-10 wt % of alkali metal element(s), 0.1-15 wt % of one
or more rare earth elements, and 0-10 wt % of one or more elements
selected from the group consisting of: magnesium, calcium, barium,
manganese, iron, nickel, cobalt, zinc, ruthenium and titanium,
based on the total weight of the catalyst.
2-14. (canceled)
15. The catalyst according to claim 1, wherein the active
ingredients comprise: 4-15 wt % of copper, 0.1-4 wt % of boron, 2-7
wt % of alkali metal element(s), 1-11 wt % of one or more rare
earth elements, and 1-8 wt % of one or more elements selected from
the group consisting of: magnesium, calcium, barium, manganese,
iron, nickel, cobalt, zinc, ruthenium and titanium.
16. The catalyst according to claim 15, wherein the active
ingredients comprise: 5-12 wt % of copper, 0.15-3 wt % of boron,
2.5-6 wt % of alkali metal element(s), 2-9 wt % of one or more rare
earth elements, and 2-6 wt % of one or more elements selected from
the group consisting of: magnesium, calcium, barium, manganese,
iron, nickel, cobalt, zinc, ruthenium and titanium.
17. The catalyst according to claim 1, wherein the support
comprises one or more of: a molecular sieve, kaolin, diatomite,
silica, alumina, titania or zirconia, and the support comprises
60-90 wt % of the total weight of the catalyst.
18. The catalyst according to claim 17, wherein the alkali metal
element is lithium, sodium, potassium or cesium.
19. The catalyst according to claim 18, wherein the rare earth
element comprises one or more lanthanide elements.
20. A method of making the catalyst of claim 1, comprising: (a)
preparing a solution by dissolving a copper-containing compound and
optionally a compound containing a transition metal other than
copper in water, then impregnating a support with the solution, and
drying the impregnated support; (b) dissolving a boron-containing
compound, an alkali metal-containing compound, an alkaline earth
metal-containing compound and a rare earth metal-containing
compound in water, then impregnating the dried solid obtained in
step (a) therein, and drying the impregnated solid; and (c)
calcining the solid obtained in step (b) at a temperature of
450-650.degree. C. for 1-5 h so as to obtain the catalyst.
21. The method according to claim 20, wherein the copper-containing
compound is a soluble salt of copper.
22. The method according to claim 20, wherein the compound
containing a transition metal other than copper is a soluble salt
of manganese, iron, nickel, cobalt, zinc, ruthenium or
titanium.
23. The method according to claim 20, wherein the boron-containing
compound is a soluble boron compound.
24. The method according to claim 20, wherein the alkali
metal-containing compound is a soluble salt of lithium, sodium or
potassium.
25. The method according to claim 20, wherein the alkaline earth
metal-containing compound is a soluble salt of magnesium, calcium
or barium.
26. The method according to claim 20, wherein the rare earth
metal-containing compound is a soluble salt of a rare earth
element.
27. The method according to claim 20, wherein the copper-containing
compound is one or more of: cupric nitrate, cupric chloride or
cupric acetate; the boron-containing compound is one or more of:
boric acid, sodium borate or potassium borate; the compound
containing the transition metal other than copper is one or more
of: nitrates, chlorides or acetates of manganese, iron, nickel,
cobalt or zinc; the alkali metal-containing compound is one or more
of: a chloride, a nitrate, an acetate, a carbonate or a borate of
sodium or potassium; the alkaline earth metal-containing compound
is one or more of: chlorides, nitrates, acetates, carbonates or
borates of magnesium or calcium; and the rare earth
metal-containing compound is one or more of: nitrates of cerium,
lanthanum, praseodymium or neodymium.
28. The method according to claim 20, wherein the active
ingredients comprise: 4-15 wt % of copper, 0.1-4 wt % of boron, 2-7
wt % of alkali metal element(s), 1-11 wt % of one or more rare
earth elements, and 1-8 wt % of one or more elements selected from
the group consisting of: magnesium, calcium, barium, manganese,
iron, nickel, cobalt, zinc, ruthenium and titanium.
29. The method according to claim 28, wherein the active
ingredients comprise: 5-12 wt % of copper, 0.15-3 wt % of boron,
2.5-6 wt % of alkali metal element(s), 2-9 wt % of one or more rare
earth elements, and 2-6 wt % of one or more elements selected from
the group consisting of: magnesium, calcium, barium, manganese,
iron, nickel, cobalt, zinc, ruthenium and titanium.
30. The method according to claim 20, wherein the support comprises
one or more of: a molecular sieve, kaolin, diatomite, silica,
alumina, titania or zirconia, and the support comprises 60-90 wt %
of the total weight of the catalyst.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a catalyst for preparing
chlorine by the oxidation of hydrogen chloride and a method for
producing the same.
BACKGROUND OF THE INVENTION
[0002] Chlorine is an important basic chemical material which has
been widely used in the industries of novel materials such as
polyurethanes, silicons, epoxy resins, chlorinated rubbers,
chlorinated polymers, chlorinated hydrocarbons and the like; the
new energy industries such as manufacture of polycrystalline
silicon and the like; the industries of fine chemicals such as
disinfectors, detergents, food additives, cosmetic additives and
the like; the industries of pesticides/pharmaceuticals such as
synthetic glycerin, chlorobenzenes, chloroacetic acid, benzyl
chloride, PCl.sub.3 and the like; as well as the industries of
paper manufacture, textile industries, metallurgy industries and
petroleum and chemical industries, etc.
[0003] Almost all chlorine is produced by the electrolysis of
sodium chloride solution in the industries. This process has two
big problems. The first one is the high electricity consumption of
up to 2760 kWh per ton chlorine, that makes the electricity
consumption of the entire chlor-alkali industry comprises about 5%
of the total industrial electricity consumption in China. The
second one is the process co-produces chlorine and sodium
hydroxide. While when sodium hydroxide requirements do not coincide
with the demand for chlorine which increases greatly due to the
rapid development of chlorine-consuming industries, oversupply of
sodium hydroxide occurs. Thus, it is necessary to find a new source
of chlorine for the further development of chlorine-consuming
industries.
[0004] On the other hand, since chlorine is used as a reaction
medium in most chlorine-consuming industries, it is not part of the
final products but discharged from reaction systems in a form of
hydrogen chloride as a by-product. As the rapid development of
chlorine-consuming industries, it is increasingly difficult to find
outlets for hydrogen chloride. The resulting by-produced
hydrochloric acid has low added value, needs high cost for
transport and storage and the sale is difficult. Also, 20-50 times
of waste water produced in subsequent applications generates a
great deal of pressure on the environment. In the case of
co-production of PVC, the domestic capacity of PVC is much
excessive, and the export amount, price and utilization of capacity
are always unsatisfied. Thus, under the current conditions, the
outlet of hydrogen chloride has become a bottleneck restricting
further development of the chlorine-consuming industries.
[0005] If the by-produced hydrogen chloride could be directly
transformed into chlorine, the closed circulation of "chlorine"
would be realized, thereby the two bottlenecks of upstream and
downstream of the chlorine-consuming industries can be essentially
solved. The oxidation of hydrogen chloride by oxygen or air as an
oxidant to prepare chlorine is a good route. This reaction is
represented by the following stoichiometric formula:
2 HCl + 1 2 O 2 Cl 2 + H 2 O - 57.7 kJ / mol ##EQU00001##
[0006] Currently, there are three different routes to carry out
this process, which are the catalytic oxidation method, the cyclic
oxidation method and the oxidative electrolysis method. Among them,
the representative cyclic oxidation method is developed by Dupont.
In this method, sulfuric acid is used as a cyclic oxidative medium
and nitric acid is used as a catalyst. Thus, its equipment
investment and operational cost are high, and its operation is
complex and lack of flexibility. The oxidative electrolysis method
can well relief the second problem, which was describe above, in
the chlor-alkali industry. However, it still has an electricity
consumption level of above 1700 kWh per ton chlorine, and thereby
the status of high electricity-consumption in the production of
chlorine is not substantially improved. Furthermore, in comparison
to ion-membrane electrolysis, the method of oxidative electrolysis
of hydrochloric acid requires more complex equipments and has no
advantages in economical efficiency and operability. This technique
is mastered only by Bayer. However, Bayer introduced the catalytic
oxidation technique from Sumitomo (Japan) while is actively finding
a market for its oxidative electrolysis technique.
[0007] Objectively, the method of catalytic oxidation of hydrogen
chloride also requires relatively large equipment investment, and
in general, the cost for production of chlorine is estimated to be
slightly higher than that of the method of ion membrane
electrolysis according to the present technique of Sumitomo
(Japan). The greatest advantage of this method is its low
electricity consumption of only about 230 kWh per ton chlorine. In
addition, it is an environment-friendly chemical process.
[0008] In the reported catalysts for hydrogen chloride oxidation,
the active ingredients mainly are metal elements such as copper,
chromium, gold and ruthenium, etc. Among them, gold and
ruthenium-based catalysts are expensive and have poor performance
in sulfur-tolerance. Chromium-based catalysts pollute the
environment due to their higher toxicity. Thus, the above two kinds
of catalysts have such problems of high economic cost or
environmental pollution or the like in use. Compared with them,
copper-based catalysts have both advantages of lower cost and being
environmentally friendly, thus are of great interests.
[0009] CN200710121298.1 discloses a catalyst containing cupric
chloride, potassium chloride and cerium chloride with alumina as
support and treated by phosphoric acid. For this catalyst the yield
of chlorine is 80.1% under the conditions that the ratio of
hydrogen chloride and oxygen is 1:1, the temperature of fixed bed
reactor is 400.degree. C., the reaction pressure is 0.1 MPa and the
space velocity of hydrogen chloride is 0.8 hr.sup.-1. However, this
catalyst has a relatively low activity, and the loss of the cupric
chloride ingredient under a higher temperature impairs the use life
of the catalyst.
[0010] CN200910027312.0 discloses a catalyst containing cupric
chloride, potassium chloride, manganese nitrate and cerium nitrate
supported on silica gel or ReY molecular sieve. With 25 g of this
catalyst, the hydrogen chloride conversion is 83.6% with both of
hydrogen chloride and oxygen flow rates of 200 ml/min at a reaction
temperature of 380.degree. C. However, this catalyst still has the
disadvantages of loss of copper ingredients and a relatively low
space velocity.
[0011] U.S. Pat. No. 4,123,389 discloses a copper-based catalyst
with silica gel, alumina or titania as a support, in which the
loading amount of active ingredients is between 25% and 70%. The
process of preparation of the catalyst needs organic solvents and
thus causes great environmental pollution.
[0012] Therefore, it is still a technical challenge in the related
field to develop a cheap, environment-friendly catalyst with high
activity and stability for production of chlorine by catalytic
oxidation of hydrogen chloride.
SUMMARY OF THE INVENTION
[0013] One object of the invention is to provide a catalyst for
production of chlorine by catalytic oxidation of hydrogen chloride
which overcomes the disadvantages of the current copper-based
catalysts and the catalyst herein has good reaction activity and
stability.
[0014] Another object of the invention is to provide a method for
preparing the above catalyst for production of chlorine by
catalytic oxidation of hydrogen chloride.
[0015] The catalyst for production of chlorine by catalytic
oxidation of hydrogen chloride according to the present invention
comprises a support and active ingredients comprising 1-20 wt % of
copper, 0.01-5 wt % of boron, 0.1-10 wt % of alkali metal
element(s), 0.1-15 wt % of one or more rare earth elements, and
0-10 wt % of one or more elements selected from magnesium, calcium,
barium, manganese, iron, nickel, cobalt, zinc, ruthenium and
titanium, the weight percent of each ingredient is based on the
total weight of the catalyst.
[0016] The method for preparing the catalyst according to the
present invention comprises the steps of:
[0017] (1) preparing a solution by dissolving a copper-containing
compound as required and optionally a compound containing a
transition metal other than copper in water, then impregnating a
support with the solution, and drying the impregnated support;
[0018] (2) dissolving a boron-containing compound, a alkali
metal-containing compound, a rare earth metal-containing compound
and a alkaline earth metal-containing compound as required in
water, then impregnating the dried solid obtained in step (1) with
the solution, and drying the impregnated solid;
[0019] (3) calcining the solid obtained in step (2) at a
temperature of 450-650.degree. C. for 1-5 h to obtain the
catalyst.
[0020] The catalyst according to the present invention can be
easily prepared. Meanwhile, comparing with gold and ruthenium-based
catalysts, the catalyst according to the invention has a relatively
lower price. Due to free of the toxic ingredients such as Cr, etc.,
the catalyst is relatively environment-friendly and does not cause
secondary pollution. Comparing with the available copper-containing
catalysts, the catalyst according to the invention has a better
stability due to the addition of boron which greatly inhibits the
loss of the copper ingredient. In addition, in the two-step
impregnation process, the copper-containing compound and the
compound containing a transition metal other than copper are
firstly loaded on the support by impregnation, and then the other
ingredients are loaded on the support by the second impregnation,
which makes the resulted catalyst has higher activity, and thereby
a higher yield of chlorine can be realized under a higher space
velocity of hydrogen chloride. Comparing with the available
copper-based catalyst, the catalyst provided by the present
invention can improve the yield of chlorine by about 1%-3%, and
even by about 4%-5%.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The catalyst for oxidation of hydrogen chloride and the
preparation method of the catalyst according to the invention are
illustrated in detail below, however the present invention is not
limited by the following description in any way. In the present
invention, the total weight of the catalyst refers to the weight of
the final catalyst product.
[0022] According to the catalyst for oxidation of hydrogen chloride
provided in the present invention, preferably the catalyst
comprises the following active ingredients: 4-15 wt %, more
preferably 5-12 wt % of copper; 0.1-4 wt %, more preferably 0.15-3
wt % of boron; 2-7 wt %, more preferably 2.5-6 wt % of alkali metal
element(s); 1-11 wt %, more preferably 2-9 wt % of one or more rare
earth elements; 1-8wt %, more preferably 2-6 wt % of one or more
elements selected from magnesium, calcium, barium, manganese, iron,
nickel, cobalt, zinc, ruthenium and titanium; as well as 60-90 wt
%, preferably 60-85 wt % of a support.
[0023] In the catalyst according to the invention, the alkali metal
element is any one selected from lithium, sodium, potassium and
cesium, preferably is sodium or potassium. The rare earth element
is at least one selected from lanthanide elements, preferably is
one or more selected from cerium, lanthanum, praseodymium and
neodymium.
[0024] The support according to the invention is at least one
selected from molecular sieve, kaolin, diatomite, silica, alumina,
titania and zirconia, preferably is molecular sieve or kaolin, and
more preferably is type Y molecular sieve (Y-zeolite).
[0025] According to the preparation method of the catalyst for
oxidation of hydrogen chloride of the invention, in steps (1) and
(2), the impregnation time preferably lasts 8-16 h and then dried
at a temperature of 70-110 .degree. C. for 12-24 h.
[0026] In the process for preparation of the catalyst, the used
copper-containing compound is a soluble salt of copper, preferably
one or more selected from cupric nitrate, cupric chloride and
cupric acetate. In general, when two or more soluble copper salts
are used, they can be combined in any proportions. More preferably,
the used copper-containing compounds are cupric nitrate and cupric
chloride.
[0027] The compound containing a transition metal other than copper
is selected from soluble salts of manganese, iron, nickel, cobalt,
zinc, ruthenium and titanium, preferably one or more selected from
corresponding nitrates, chlorides and acetates of manganese, iron,
nickel, cobalt, zinc and titanium, and more preferably one or more
of corresponding nitrates, chlorides and acetates of manganese,
iron, cobalt and zinc.
[0028] The boron-containing compound is one or two or three of
boric acid, sodium borate and potassium borate. The alkali metal
compound is one or more selected from chlorides, nitrates,
acetates, carbonates and borates of lithium, sodium, potassium,
preferably one or more selected from chloride, nitrate, acetate,
carbonate and borate of sodium or potassium. The alkaline earth
metal compound is one or more selected from chlorides, nitrates,
acetates, carbonates and borates of magnesium, calcium and barium,
and preferably one or more selected from chlorides, nitrates,
acetates, carbonates and borates of magnesium and calcium. The rare
earth metal compound is one or more selected from nitrates and
chlorides of cerium, lanthanum, praseodymium and neodymium,
preferably one or more selected from the nitrates.
[0029] The catalyst of the invention is useful in the reaction for
producing chlorine by catalytic oxidation of hydrogen chloride,
which may be carried out in a fixed bed reactor or in other
reactors suitable for such reactions.
[0030] The reaction conditions for producing chlorine by the
oxidation of hydrogen chloride are that: the reaction temperature
is 320-460.degree. C., preferably 360-400.degree. C.; the reaction
pressure is 0.1-0.6 MPa, preferably 0.1-0.35 MPa; the mole ratio
between hydrogen chloride and oxygen is 0.5-9:1, preferably 1-4:1;
and the mass space velocity of hydrogen chloride is 0.1-2.5
h.sup.-1, preferably 0.5-2.sup.-1.
[0031] The present invention provides the catalyst for producing
chlorine by the oxidation of hydrogen chloride, which comprises a
support and the metal salts or metal oxides applied thereon. The
metal salts or metal oxides are loaded onto the support such that
the catalyst comprises: 1-20 wt % of copper, 0.01-5 wt % of boron,
0.1-10 wt % of alkali metal element, 0.1-15 wt % of one or two or
more of rare earth elements, .gtoreq.0-10 wt % of one or two or
more of magnesium, calcium, barium, manganese, iron, nickel,
cobalt, zinc, ruthenium or titanium, each based on the total weight
of the catalyst.
[0032] The catalyst and the preparation method thereof according to
the invention will be further described in detail with reference to
the following Examples. But the present invention is not limited by
these Examples in any way. In the following Examples and
Comparative Examples, "%" used refers to "wt %" unless specified
otherwise.
[0033] The following Examples and Comparative Examples are carried
out in a fixed bed reactor. The general reaction procedure is as
follows: hydrogen chloride and oxygen are fed into the top of a
quartz tube reactor with their pressures respectively controlled by
pressure stabilization valves and their flow rates respectively
controlled by mass flow controllers, and the gas flows pass the
catalyst bed to conduct the reaction after preheated with quartz
sands. The reaction product is absorbed by an excess potassium
iodide solution, and the amount of resultant chlorine is measured
by the iodometric method and the amount of unreacted hydrogen
chloride is measured by acid-base titration for calculating the
yield of chlorine.
[0034] In addition, in the following Examples and Comparative
Examples, the aqueous solution containing active ingredients is
slight excess in impregnation steps, and the solid is directly
dried after impregnation, thus there is no loss of the active
ingredients.
EXAMPLE 1
[0035] In a 40 ml of aqueous solution that contains 26.3 g
CuCl.sub.2.2H.sub.2O, 60 g of HY molecular sieve (rare earth HY
molecular sieve, manufactured by Mingmeiyoujie Mining Co. Ltd.,
Mingguang City, the same below) is impregnated for 12 h, then dried
at 90.degree. C. for 16 h. The resultant solid is re-dispersed in a
50 ml of aqueous solution that contains 0.92 g H.sub.3BO.sub.3,
4.95 g KCl, 8.15 g Ce(NO.sub.3).sub.3.6H.sub.2O and 4.05 g
Nd(NO.sub.3).sub.3.6H.sub.2O to perform impregnation for 12 h, then
dried at 90.degree. C. for 16 h. The dried solid is calcined at
500.degree. C. for 4 h to obtain 90 g of active catalyst. It is
tableted to obtain catalyst granules of 30-60 mesh. 6 g of the
catalyst of 30-60 mesh is loaded in a fixed bed reactor to conduct
a reaction with of the flow rates of hydrogen chloride and oxygen
of 100 ml/min respectively, with the reaction temperature at
380.degree. C. and the reaction pressure at 0.18 MPa. After 4 h of
reaction, the chlorine yield is 88.6%; and after 100 h of reaction,
the chlorine yield is 89.0%. The activity of the catalyst is
stable. After 1000 h of reaction, the chlorine yield is 87.8%, that
is, the catalyst still keeps quite a high activity.
COMPARATIVE EXAMPLE 1
[0036] In a 42 ml of aqueous solution that contains 26.3 g
CuCl.sub.2.2H.sub.2O, 60 g HY molecular sieve is impregnated for 12
h, then dried at 90.degree. C. for 16 h. The resultant solid is
re-dispersed in a 54 ml of aqueous solution that contains 4.95 g
KCl, 8.15 g Ce(NO.sub.3).sub.3.6H.sub.2O and 4.05 g
Nd(NO.sub.3).sub.3.6H.sub.2O to perform impregnation for 12 h, then
dried at 90.degree. C. for 16 h. After being calcined at
500.degree. C. for 4 h, 90 g of active catalyst is obtained. It is
tableted to obtain catalyst granules of 30-60 mesh.
[0037] With the same reaction conditions as in Example 1, the
chlorine yield is 88.2% after 4 h of reaction, and is 86.4% after
100 h of reaction. Obviously, the catalyst has a relatively poor
stability.
[0038] It can be concluded from the comparison of Example 1 and
Comparative Example 1 that the addition of boron element improves
the stability of the catalyst.
EXAMPLE 2
[0039] In a 41 ml of aqueous solution that contains 26.3 g
CuCl.sub.2.2H.sub.2O, 60 g kaolin is impregnated for 12 h, then
dried at 90.degree. C. for 16 h. The resultant solid is
re-dispersed in a 49 ml of aqueous solution that contains 1.15 g
H.sub.3BO.sub.3, 4.95 g KCl, 8.15 g Ce(NO.sub.3).sub.3.6H.sub.2O
and 4.05 g La(NO.sub.3).sub.3.6H.sub.2O to perform impregnation for
12 h, then dried at 90.degree. C. for 16 h. After being calcined at
500.degree. C. for 4 h, 90 g of active catalyst is obtained. It is
tableted to obtain catalyst granules of 30-60 mesh. With the same
reaction conditions as in Example 1, the chlorine yield is 86.1%
after 4 h of reaction and is 85.8% after 100 h of reaction. The
activity of the catalyst substantially remains unchanged. After
1000 h of reaction, the catalyst still keeps its activity with the
chlorine yield of 85.4%.
EXAMPLE 3
[0040] In a 45 ml of aqueous solution that contains 17.8 g
CuCl.sub.2.2H.sub.2O and 11.5 g Co(NO.sub.3).sub.2.6H.sub.2O, 60 g
HY molecular sieve is impregnated for 12 h, then dried at
90.degree. C. for 16 h. The resultant solid is re-dispersed in a 50
ml of aqueous solution that contains 0.46 g H.sub.3BO.sub.3, 4.95 g
KCl, 8.15 g Ce(NO.sub.3).sub.3.6H.sub.2O and 4.05 g
Pr(NO.sub.3).sub.3.6H.sub.2O to perform impregnation for 12 h, then
dried at 90.degree. C. for 16 h. After being calcined at
500.degree. C. for 4 h, 86 g of active catalyst is obtained. It is
tableted to obtain catalyst granules of 30-60 mesh. With the same
reaction conditions as in Example 1, the chlorine yield is 86.4%
after 4 h of reaction and is 86.8% after 100 h of reaction. The
catalyst keeps a stable activity. The chlorine yield is 86.0% after
1000 h of reaction.
EXAMPLE 4
[0041] In a 40 ml of aqueous solution that contains 26.3 g
CuCl.sub.2.2H.sub.2O, 60 g HY molecular sieve is impregnated for 12
h, then dried at 90.degree. C. for 16 h. The resultant solid is
re-dispersed in a 54 ml of aqueous solution that contains 0.92 g
H.sub.3BO.sub.3, 3.05 g KCl, 1.35 g Mg(NO.sub.3).sub.2.2H.sub.2O,
8.15 g Ce(NO.sub.3).sub.3.6H.sub.2O and 4.05 g
La(NO.sub.3).sub.3.6H.sub.2O to perform impregnation for 12 h, then
dried at 90.degree. C. for 16 h. After being calcined at
500.degree. C. for 4 h, 89 g of active catalyst is obtained. It is
tableted to obtain catalyst granules of 30-60 mesh.
[0042] In a fixed bed reactor, 6 g of the catalyst prepared in
Example 4 is loaded to conduct a reaction with the flow rates of
hydrogen chloride and oxygen of 150 ml/min respectively, with the
reaction temperature at 383.degree. C. and the reaction pressure at
0.18 MPa. After 4 h of reaction, the chlorine yield is 85.7%, and
after 100 h of reaction, is 85.2%. The activity of the catalyst
substantially keeps activity. After 1000 h of reaction, the
chlorine yield is 85.1%.
COMPARATIVE EXAMPLE 2
[0043] In a 65 ml of aqueous solution that contains 26.3 g
CuCl.sub.2.2H.sub.2O, 3.05 g KCl, 1.35 g Mg(NO.sub.3).sub.2
2H.sub.2O, 8.15 g Ce(NO.sub.3).sub.3.6H.sub.2O and 4.05 g
La(NO.sub.3).sub.3.6H.sub.2O, 60 g HY molecular sieve is
impregnated for 12 h, then dried at 90.degree. C. for 16 h. After
being calcined at 550.degree. C. for 4 h, 90 g of active catalyst
is obtained. It is tableted to obtain catalyst granules of 30-60
mesh. With the same hydrogen chloride oxidation reaction conditions
as in Example 4, the chlorine yield is 82.9% after 4 h of reaction
and is 82.0% after 100 h of reaction. The chlorine yield is 80.2%
after 1000 h of reaction
It can be concluded from the comparison between Example 4 and
Comparative Example 2 that the catalyst obtained through the
two-step impregnation process has a significantly higher activity
than that of the catalyst prepared by the one-step impregnation
process has. Use of the inventive catalyst in a reaction for
production of chlorine by oxidation of hydrogen chloride can
increase the chlorine yield by about 3 percent.
* * * * *