CA1086922A - Purification of chlorine gas - Google Patents
Purification of chlorine gasInfo
- Publication number
- CA1086922A CA1086922A CA286,119A CA286119A CA1086922A CA 1086922 A CA1086922 A CA 1086922A CA 286119 A CA286119 A CA 286119A CA 1086922 A CA1086922 A CA 1086922A
- Authority
- CA
- Canada
- Prior art keywords
- chlorine
- gas
- hydrate crystals
- crude
- chlorine gas
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/005—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by heat treatment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/002—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by condensation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B7/00—Halogens; Halogen acids
- C01B7/01—Chlorine; Hydrogen chloride
- C01B7/015—Chlorine hydrates; Obtaining chlorine therefrom
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Analytical Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A crude chlorine gas is purified by cooling the crude chlorine gas in the presence of water so as to crystallize chlorine in the crude chlorine gas as chlorine hydrate crystals and separating the other components of the crude chlorine gas from chlorine hydrate crystals and then, decomposing the chlorine hydrate crystals to obtain chlorine gas.
A crude chlorine gas is purified by cooling the crude chlorine gas in the presence of water so as to crystallize chlorine in the crude chlorine gas as chlorine hydrate crystals and separating the other components of the crude chlorine gas from chlorine hydrate crystals and then, decomposing the chlorine hydrate crystals to obtain chlorine gas.
Description
~86~22 The present invention relates to a purification of chlorine gas. More particularly, it relates to a process for preparing chlorine gas of high purity by purifying a crude chlorine gas which contains at least one of oxygen, hydrogen and carbon dioxide gas admixed with the chlorine.
Chlorine gas has been used :in various industrial fields.
When chlorine gas is used for the chlorination of organic compounds, if the chlorine gas contains another gas such as oxygen, the oxygen content increases with the consumption of the chlorine in the reaction forming an explosive gas with the organic compound whereby certain problems such as explosions may be caused and water is formed in the reaction of the organic compound corroding the apparatus. Accordingly, it is necessary to use the chlorine gas having a high purity.
Chlorine gas has been prepared industrially by the electrolysis of sodium chloride, by the Weldon method using hydrochloric acid with manganese chloride or by the Deacon-Hurter method oxidizing hydrochloric acid. The crude chlorine gas produced by these methods contains relatively large amoun~s of impurities. The crude chlorine gas prepared by the electrolysis of sodium chloride has relatively higher purity in comparison with other methods, however the crude chlorine gas contains about
Chlorine gas has been used :in various industrial fields.
When chlorine gas is used for the chlorination of organic compounds, if the chlorine gas contains another gas such as oxygen, the oxygen content increases with the consumption of the chlorine in the reaction forming an explosive gas with the organic compound whereby certain problems such as explosions may be caused and water is formed in the reaction of the organic compound corroding the apparatus. Accordingly, it is necessary to use the chlorine gas having a high purity.
Chlorine gas has been prepared industrially by the electrolysis of sodium chloride, by the Weldon method using hydrochloric acid with manganese chloride or by the Deacon-Hurter method oxidizing hydrochloric acid. The crude chlorine gas produced by these methods contains relatively large amoun~s of impurities. The crude chlorine gas prepared by the electrolysis of sodium chloride has relatively higher purity in comparison with other methods, however the crude chlorine gas contains about
2 to 10% of oxygen and other gases, such as carbon dioxide gas, hydrogen gas, as impurities. When the electrolysis of sodium chloride is carried out using a metallic electrode, the crude chlorine gas may contain relatively high oxygen gas content.
Accordingly, when the chlorine gas is to be used in the fields where chlorine gas having high purity is used, it is necessary to purify the crude chlorine gas.
It is known to purify the crude chlorine gas by the recovery of chlorine gas after liquefication of the chlorine gas. Such a method as the compression method of recovery of -- 1 -- .
,.' .
8~9;~:Z
chlorine gas by liquiefying chlorine gas after drying the crude chlorine gas compressing the gas at about 8 to 10 atm. pressure cooling the gas at about 15 to 20C and then, vaporizing the liquefied chlorine. Another such method is the cooling method of recovery of chlorine gas by lique~ying chlorine gas after drying the crude chlorine gas, cooling the gas at about -40C
under about 1 atm.pressure and then, vaporizing the liquefied chlorine. However, these methods have disadvantages because a large amount of a drying agent is needed for completely drying the gas to liquefy the gas and a large power consumption of the apparatus for compression and cooling is needed providing a high cost for the purification. When the purification is carried out in the compression condition, the condition of the operation may be especially severe.
When hydrogen gas is present with oxygen as the impurity gases, the hydrogen content in the residual gas increases with the separation of chlorine gas and an explosive gas may be formed by the residual chlorine gas with the hydrogen gas and oxygen gas.
Accordingly, it is required that the crude chlorine gas is diluted with a gas inert to hydrogen before liquefying the crude chlorine gas by cooling. The efficiency of the purification of chlorine gas has been disadvantageously lowered.
In another conventional method of purification of the crude chlorine gas, only chlorine gas is absorbed into a solvent such as sulfur chloride or carbon tetrachloride to separate the chlorine gas from the impurity gases and then, chlorine gas is removed. The latter method could be economically carried out however, the solvent disadvantageously may be incorporated in the resulting chlorine gas and the separa-tios of the solvent has not been easy.
The present invention provides a method of purification of chlorine gas without liquefying it with drying and without :L~8~922 ,: .
absorbing the chlorine gas into a solvent to yield high purity chlorine at low cost.
According to the present invention there is provided a process for the purification of chlorine gas which comprises cooling a crude chlorine gas in the presence of water sufficient to form chlorine hydrate crystals and a heat transfer medium so as to crystallize chlorine in the crude chlorine gas as chlorine hydrate crystals; separating the other components of the crude chlorine gas from chlorine hydrate crystals and then, decomposing the chlorine hydrate crystals to obtain chlorine gas.
Thus according to the present invention the crude chlorine gas is cooled in the presence of wa-ter to crystallize chlorine from the crude chlorine gas as chlorine hydrate crystals, and the other components of the crude chlorine gas separated frGm chlorine and then the chlorine hydrate crystals are decomposed to obtain chlorine gas.
The method of the present invention has the following advantages.
The chlorine in the crude chlorine gas is crystallized as chlorine hydrate crystals so that it is unnecessary to compress it to a too high pressure or to keep it in too low temperature or to completely dry the crude chlorine gas in the process.
Accordingly, the~process and the apparatus for the purification can be simplified. Moreover, it is possible to carry out the process under the atmospheric pressure and to decrease the power consumption for cooling the gas.
The crude chlorine gas is cooled in the presence of water so that the chlorine in the crude chlorine gas is crystallized to form the chlorine hydrate crystals. The other components in the crude chlorine gas such as oxygen, hydrogen or carbon dioxide gas are in gaseous state under the conditions of forming the chlorine hydrate crystals, and can be easily separated by removing these gases such as by suction.
The method o~ the present invention will be illustrated in detail.
The crude chlorine gas used ln the method of the presènt invention contains chlorine and o-ther impurity gases which are not solidified under the conditions of crystallizing chlorine as the chlorine hydrate crystals, such as oxygen gas, hydrogen gas and carbon dioxide gas.
The erude ehlorine gas eontaining impurities sueh as oxygen ean be obtained by the electrolysis of sodium ehloride -using a metallic electrode. Thus, the crude chlorine gas can be obtained by mercury electrolysis, asbestos diaphragm type electrolysis and ion-exchange membrane type electrolysis. In these cases, the crude chlorine gases may contain 90 to 98 vol.%
of ehlorine; 1.5 to 10 vol.% of oxygen; 0.1 to 0.2 vol.% of hydrogen and 0.5 to 0.6 vol.% of carbon dioxide gas. These eontents may vary depending upon the kind of the anode.
The ehlorine hydrate erystals are mainly CQ2-6H2O or CR2-8H2O. Other chloride hydrate crystals include those between six to eight hydrates or less than six hydrate or more than eight hydrate. The ehlorine hydrate crystals can be formed by crystalli-zing chlorine gas under various conditions of a temperature and a pressure in the presence of water. When CQ2-6H2O is prepared, it can be obtained by cooling chlorine gas at the chlorine partial pressure of 1 atm. at a temperature lower than 9.6C. When the ehlorine hydrate crystals are formed by cooling chlorine gas in the presence of water, various methods can be employed.
For example, the erude ehlorine gas is eooled in the presenee of water in an amount suffieient to form the ehlorlne . hydrate erystals from chlorine gas in the crude chlorine gas such as at least 6 moles of water per 1 mole of chlorine for CQ2-6H2O.
Indirect cooling with a system for cooling with a heat exchange or the other methods can be employed.
.', . . ,, ', ' :' ' , . .
.. . ~ .... .
' ~8~i92Z
For -the formation of the chlorine hydrate crystals, the method of coollng the crude chloxine gas and water for forming the chlorine hydrate crystals in the presence of a heat transfer medium ~r-~ used. The method of using -the heat transfer medium is ~Ye~aab~¢t because of the following reasons.
The heat transfer medium while being as the medium for heat transfer may also be used as the medium for transferring chlorine hydrate crystals (hereinafter heat transfer medium is referred as a transfer medium). Accordingly, the transfer medium should be substantially inert to chlorine and it is preferably the liquid~from the crystallization of the chlorine hydrate to the decomposition thereof and it is further preferable to have low-vaporizing properties.
Suitable transfer media include halohydrocarbons such as dichlorofluoromethane, chlorodifluoromethane and water. It is preferable to use water from the viewpoint of vaporizing property.
Water can be the transfer medium as well as the source of water for forming chlorine hydrate crystals.
In this case, the method of cooling the crude chlorine gas can be the method of contacting the crude chlorine gas with the transfer medium which is previously cooled. In this method, -water can be previously mixed with chlorine gas or water can be also mixed with the transfer medium. In the other method, the mixture of the crude chlorine gas, water and the transfer medium can be directly or indirectly cooled. For example, when the cooled transfer medium is contacted with the crude chlorine gas, the crude chlori.ne gas can be countercurrently contacted with the cooled transfer medium in the presence of water or the crude chlorine gas can be fed into the cooled transfer medium or i-t can be contacted by the other methods.
Whenchlorine gas is crystallized to form thechlorine hydrate crystals, the cooling temperature is depending upon the 8~922 pressure in the cooling operation. It is preferable to form the chlorine hydrate crystals under the Eollowing condition.
log P _ 16.043 - (P : mmHg; T : K), 270 K < T < 310K.
The temperature T is preferably in a range of 271K
to 285K. When it is cooled under such temperature condition, the chlorine hydrate crystals can be formed under the chlorine partial pressure of about 1 atm. ~-. 760 mmHg). Accordingly, it can be carried out under substantailly atmospheric pressure.
The chlorine in the crude chlorine gas is crystallized as the chlorine hydrate crystals by cooling. The other gases in -the crude chlorine gas are in gaseous state whereby the other gases can be separated such as by the suction. The separated chlorine hydrate crystals are decomposed to generate chlorine gas having high purity. The decomposition of the chlorine hydrate crystals is a reverse process to the crystallization with respect to the chlorine hydrate crystals. Accordingly, the step of decomposing the chlorine hydrate crystals can be attained by . .
decreasing the pressure to less than the decomposition pressure ~-of the chlorine hydrate crystals or increasing the temperature to higher than the temperature for the decomposition pressure.
~or example, when the crude chlorine gas is cooled under 1 atm. to a temperature lower than 9.6C to form the chlorine hydrate crystals, the temperature is raised to higher than 9.6C
or the pressure is decreased to lower than 1 atm. However, it is preferable to decompose the crystals by controlling -the pressure because of the following reason.
- The crystallization for forming the chlorine hydrate crystals and the decomposition of the chlorine hydrate crystals can be carried out in one reactor. However, it is preferable in the practical process to separate the step of formation of the . ~
- 1~86922 chlorine hydrate crystals and the step of decomposition of the chlorine hydrate crystals.
In the latter process, it is especially effective to use the transfer medium as described. That is, in the step of formation of the chlorine hydrate crystals, the crude chlorine gas is contacted with the caoled trans~er medium in the presence -of water whereby most of chlorine in the crude chlorine gas is ;~
crystallized as the chlorine hydrate crystals. The other gases in the crude chlorine gas are in gaseous state and are separated from the chlorine hydrate crystals. The chlorine hydrate crystals with the transfer medium as a slurry are fed to the decomposition step of the chlorine hydrate crystals.
In the decomposition step of the chlorine hydrate crystals, the pressure is kept in lower than the decomposition pressure of the chlorine hydrate crystals, whereby the chlorine hydrate crystals are decomposed to generate chlorine gas.
However, the transfer medium is cooled by the endothermic decomposition reaction of the chlorine hydrate crystals, and the cooled transfer medium is recycled to the formation of the chlorine hydrate crystals wherein the transfer medium is used for cooling the crude chlorine gas. Accordingly, the cooling energy in the step of formation of the chlorine hydrate crystals can be substantially decreased.
When the transfer medium is used, the transfer medium imparts the heat transfer effect and it is used for transferring the chlorine hydrate crystals and it is used to control the pressure in the step of decomposition of the chlorine hydrate crystals. Accordingly, efEective utiliza-tion of heat can be . attained.
The following effects can be also expected by using the transfer medium.
When the crude chlorine gas contains an ac-tive component ~869~
such as hydrogen which reacts with chlorine or oxygen, the ratios of hydrogen and oxygen in the gas are increased relatively by crystallizing chlorine gas as the chlorine hydrate cyrstals, whereby the composition of the gas may become the expensive gas range. However, when the crude chlorine gas is fed into the cooled transfer medium in the presence o~ water, the explosion can be prevented and effective operation can be attained. The crude chlorine gas is dispersed into the cooled transfer medium wherein the chlorine hydrate crystals are formed by reacting chlorine with water. Thus, the content of hydrogen and oxygen in the crude chlorine gas are increased with the conversion of chlorine gas to the chlorine hydrate crystals whereby an explosive gas may be formed. However, the crude chlorine gas is cooled by the transfer medium so as to prevent the explosion. The crude --chlorine gas is dispersed into the transfer medium whereby a chain explosion can be prevented. The explosive gas is floated through the transfer medium and is discharged. When it is discharged, it can be diluted by feeding an inert gas such as air, nitrogen gas and other inert gas whereby the explosion can be prevented. In accordance with this process, it is unnecessary to decrease the formation of the chlorine hydrate crystals so as to change the composition of the residual gas out of the explosive gas range.
As described, most of chlorine in the crude chlorine gas is crystallized as the chlorine hydrate crystals and then the chlorine hydrate crystals are decomposed to obtain chlorine gas having high purity. When it is necessary to effectively crystallize chlorine in the crude chlorine gas as the chlorine hydrate crystals, it is preferable to carry out the step of form-ation of the chlorine hydrate crystals by multi-steps. The purpose can be at-tained by combining the first and second steps of formation of the chlorine hydrate crystals.
~, _ . .
, - ~8~922 That is, the crude chlorine gas is countercurrently contacted with the cooled transEer medium in the presence of water under about the atmospheric pressure whereby most of chlorine in the crude chlorine gas is crystallized to form the chlorine hydrate crystals in the first crystallization step and the residual chlorine gas and other gases, such as oxygen and hydrogen are taken out from the first crystallization step andthese gases are fed to the seconcl crystallization step. The chlorine partial pressure in the gases, is low whereby the gases are preferably slightly compressed. In the second crystallization step,the partial pressures of the bther gases such as oxygen and hydrogen beside chlorine in the crude chlorine gas are higher.
When the chlorine gas is crystallized as the chlorine hydrate crystals, the explosive gases may be generated as described above. Accordingly, the crude chlorine gas is fed into the cooled transfer medium to form the chlorine hydrate crystals.
The chlorine hydrate crystals crystallized in the first and second crystallization steps, are fed, with the thermal medium in the Eorm of a slurry, to the decomposition step of the chlorine - hydrate crystals.
Thus, the crude chlorine gas is cooled under about atmospheric pressure to crystallize most of chlorine as the chlorine hydrate crystals in the first crystallization step and the residual chlorine is cooled under the pressure slightly higher than 1 atm. in the second crystallization step, whereby chlorine in the crude chlorine gas can be substantially crystallized as the chlorine hydrate crystals in high efficiency.
The case using water as the transfer medium will be illustrated.
The advantages of the use of water as the transfer medium are as follows:
(1) Water can be the source of crystal water for forming the chlorine hydrate crystals.
g _ ,.
-~869;~2 (2) Water is less vaporizable and a large amount of water will not be incorporated in the chlorine gas when the chlorine hydrate crystals are decomposed.
Accordingly, when the chlorine gas is to be used in the fields where chlorine gas having high purity is used, it is necessary to purify the crude chlorine gas.
It is known to purify the crude chlorine gas by the recovery of chlorine gas after liquefication of the chlorine gas. Such a method as the compression method of recovery of -- 1 -- .
,.' .
8~9;~:Z
chlorine gas by liquiefying chlorine gas after drying the crude chlorine gas compressing the gas at about 8 to 10 atm. pressure cooling the gas at about 15 to 20C and then, vaporizing the liquefied chlorine. Another such method is the cooling method of recovery of chlorine gas by lique~ying chlorine gas after drying the crude chlorine gas, cooling the gas at about -40C
under about 1 atm.pressure and then, vaporizing the liquefied chlorine. However, these methods have disadvantages because a large amount of a drying agent is needed for completely drying the gas to liquefy the gas and a large power consumption of the apparatus for compression and cooling is needed providing a high cost for the purification. When the purification is carried out in the compression condition, the condition of the operation may be especially severe.
When hydrogen gas is present with oxygen as the impurity gases, the hydrogen content in the residual gas increases with the separation of chlorine gas and an explosive gas may be formed by the residual chlorine gas with the hydrogen gas and oxygen gas.
Accordingly, it is required that the crude chlorine gas is diluted with a gas inert to hydrogen before liquefying the crude chlorine gas by cooling. The efficiency of the purification of chlorine gas has been disadvantageously lowered.
In another conventional method of purification of the crude chlorine gas, only chlorine gas is absorbed into a solvent such as sulfur chloride or carbon tetrachloride to separate the chlorine gas from the impurity gases and then, chlorine gas is removed. The latter method could be economically carried out however, the solvent disadvantageously may be incorporated in the resulting chlorine gas and the separa-tios of the solvent has not been easy.
The present invention provides a method of purification of chlorine gas without liquefying it with drying and without :L~8~922 ,: .
absorbing the chlorine gas into a solvent to yield high purity chlorine at low cost.
According to the present invention there is provided a process for the purification of chlorine gas which comprises cooling a crude chlorine gas in the presence of water sufficient to form chlorine hydrate crystals and a heat transfer medium so as to crystallize chlorine in the crude chlorine gas as chlorine hydrate crystals; separating the other components of the crude chlorine gas from chlorine hydrate crystals and then, decomposing the chlorine hydrate crystals to obtain chlorine gas.
Thus according to the present invention the crude chlorine gas is cooled in the presence of wa-ter to crystallize chlorine from the crude chlorine gas as chlorine hydrate crystals, and the other components of the crude chlorine gas separated frGm chlorine and then the chlorine hydrate crystals are decomposed to obtain chlorine gas.
The method of the present invention has the following advantages.
The chlorine in the crude chlorine gas is crystallized as chlorine hydrate crystals so that it is unnecessary to compress it to a too high pressure or to keep it in too low temperature or to completely dry the crude chlorine gas in the process.
Accordingly, the~process and the apparatus for the purification can be simplified. Moreover, it is possible to carry out the process under the atmospheric pressure and to decrease the power consumption for cooling the gas.
The crude chlorine gas is cooled in the presence of water so that the chlorine in the crude chlorine gas is crystallized to form the chlorine hydrate crystals. The other components in the crude chlorine gas such as oxygen, hydrogen or carbon dioxide gas are in gaseous state under the conditions of forming the chlorine hydrate crystals, and can be easily separated by removing these gases such as by suction.
The method o~ the present invention will be illustrated in detail.
The crude chlorine gas used ln the method of the presènt invention contains chlorine and o-ther impurity gases which are not solidified under the conditions of crystallizing chlorine as the chlorine hydrate crystals, such as oxygen gas, hydrogen gas and carbon dioxide gas.
The erude ehlorine gas eontaining impurities sueh as oxygen ean be obtained by the electrolysis of sodium ehloride -using a metallic electrode. Thus, the crude chlorine gas can be obtained by mercury electrolysis, asbestos diaphragm type electrolysis and ion-exchange membrane type electrolysis. In these cases, the crude chlorine gases may contain 90 to 98 vol.%
of ehlorine; 1.5 to 10 vol.% of oxygen; 0.1 to 0.2 vol.% of hydrogen and 0.5 to 0.6 vol.% of carbon dioxide gas. These eontents may vary depending upon the kind of the anode.
The ehlorine hydrate erystals are mainly CQ2-6H2O or CR2-8H2O. Other chloride hydrate crystals include those between six to eight hydrates or less than six hydrate or more than eight hydrate. The ehlorine hydrate crystals can be formed by crystalli-zing chlorine gas under various conditions of a temperature and a pressure in the presence of water. When CQ2-6H2O is prepared, it can be obtained by cooling chlorine gas at the chlorine partial pressure of 1 atm. at a temperature lower than 9.6C. When the ehlorine hydrate crystals are formed by cooling chlorine gas in the presence of water, various methods can be employed.
For example, the erude ehlorine gas is eooled in the presenee of water in an amount suffieient to form the ehlorlne . hydrate erystals from chlorine gas in the crude chlorine gas such as at least 6 moles of water per 1 mole of chlorine for CQ2-6H2O.
Indirect cooling with a system for cooling with a heat exchange or the other methods can be employed.
.', . . ,, ', ' :' ' , . .
.. . ~ .... .
' ~8~i92Z
For -the formation of the chlorine hydrate crystals, the method of coollng the crude chloxine gas and water for forming the chlorine hydrate crystals in the presence of a heat transfer medium ~r-~ used. The method of using -the heat transfer medium is ~Ye~aab~¢t because of the following reasons.
The heat transfer medium while being as the medium for heat transfer may also be used as the medium for transferring chlorine hydrate crystals (hereinafter heat transfer medium is referred as a transfer medium). Accordingly, the transfer medium should be substantially inert to chlorine and it is preferably the liquid~from the crystallization of the chlorine hydrate to the decomposition thereof and it is further preferable to have low-vaporizing properties.
Suitable transfer media include halohydrocarbons such as dichlorofluoromethane, chlorodifluoromethane and water. It is preferable to use water from the viewpoint of vaporizing property.
Water can be the transfer medium as well as the source of water for forming chlorine hydrate crystals.
In this case, the method of cooling the crude chlorine gas can be the method of contacting the crude chlorine gas with the transfer medium which is previously cooled. In this method, -water can be previously mixed with chlorine gas or water can be also mixed with the transfer medium. In the other method, the mixture of the crude chlorine gas, water and the transfer medium can be directly or indirectly cooled. For example, when the cooled transfer medium is contacted with the crude chlorine gas, the crude chlori.ne gas can be countercurrently contacted with the cooled transfer medium in the presence of water or the crude chlorine gas can be fed into the cooled transfer medium or i-t can be contacted by the other methods.
Whenchlorine gas is crystallized to form thechlorine hydrate crystals, the cooling temperature is depending upon the 8~922 pressure in the cooling operation. It is preferable to form the chlorine hydrate crystals under the Eollowing condition.
log P _ 16.043 - (P : mmHg; T : K), 270 K < T < 310K.
The temperature T is preferably in a range of 271K
to 285K. When it is cooled under such temperature condition, the chlorine hydrate crystals can be formed under the chlorine partial pressure of about 1 atm. ~-. 760 mmHg). Accordingly, it can be carried out under substantailly atmospheric pressure.
The chlorine in the crude chlorine gas is crystallized as the chlorine hydrate crystals by cooling. The other gases in -the crude chlorine gas are in gaseous state whereby the other gases can be separated such as by the suction. The separated chlorine hydrate crystals are decomposed to generate chlorine gas having high purity. The decomposition of the chlorine hydrate crystals is a reverse process to the crystallization with respect to the chlorine hydrate crystals. Accordingly, the step of decomposing the chlorine hydrate crystals can be attained by . .
decreasing the pressure to less than the decomposition pressure ~-of the chlorine hydrate crystals or increasing the temperature to higher than the temperature for the decomposition pressure.
~or example, when the crude chlorine gas is cooled under 1 atm. to a temperature lower than 9.6C to form the chlorine hydrate crystals, the temperature is raised to higher than 9.6C
or the pressure is decreased to lower than 1 atm. However, it is preferable to decompose the crystals by controlling -the pressure because of the following reason.
- The crystallization for forming the chlorine hydrate crystals and the decomposition of the chlorine hydrate crystals can be carried out in one reactor. However, it is preferable in the practical process to separate the step of formation of the . ~
- 1~86922 chlorine hydrate crystals and the step of decomposition of the chlorine hydrate crystals.
In the latter process, it is especially effective to use the transfer medium as described. That is, in the step of formation of the chlorine hydrate crystals, the crude chlorine gas is contacted with the caoled trans~er medium in the presence -of water whereby most of chlorine in the crude chlorine gas is ;~
crystallized as the chlorine hydrate crystals. The other gases in the crude chlorine gas are in gaseous state and are separated from the chlorine hydrate crystals. The chlorine hydrate crystals with the transfer medium as a slurry are fed to the decomposition step of the chlorine hydrate crystals.
In the decomposition step of the chlorine hydrate crystals, the pressure is kept in lower than the decomposition pressure of the chlorine hydrate crystals, whereby the chlorine hydrate crystals are decomposed to generate chlorine gas.
However, the transfer medium is cooled by the endothermic decomposition reaction of the chlorine hydrate crystals, and the cooled transfer medium is recycled to the formation of the chlorine hydrate crystals wherein the transfer medium is used for cooling the crude chlorine gas. Accordingly, the cooling energy in the step of formation of the chlorine hydrate crystals can be substantially decreased.
When the transfer medium is used, the transfer medium imparts the heat transfer effect and it is used for transferring the chlorine hydrate crystals and it is used to control the pressure in the step of decomposition of the chlorine hydrate crystals. Accordingly, efEective utiliza-tion of heat can be . attained.
The following effects can be also expected by using the transfer medium.
When the crude chlorine gas contains an ac-tive component ~869~
such as hydrogen which reacts with chlorine or oxygen, the ratios of hydrogen and oxygen in the gas are increased relatively by crystallizing chlorine gas as the chlorine hydrate cyrstals, whereby the composition of the gas may become the expensive gas range. However, when the crude chlorine gas is fed into the cooled transfer medium in the presence o~ water, the explosion can be prevented and effective operation can be attained. The crude chlorine gas is dispersed into the cooled transfer medium wherein the chlorine hydrate crystals are formed by reacting chlorine with water. Thus, the content of hydrogen and oxygen in the crude chlorine gas are increased with the conversion of chlorine gas to the chlorine hydrate crystals whereby an explosive gas may be formed. However, the crude chlorine gas is cooled by the transfer medium so as to prevent the explosion. The crude --chlorine gas is dispersed into the transfer medium whereby a chain explosion can be prevented. The explosive gas is floated through the transfer medium and is discharged. When it is discharged, it can be diluted by feeding an inert gas such as air, nitrogen gas and other inert gas whereby the explosion can be prevented. In accordance with this process, it is unnecessary to decrease the formation of the chlorine hydrate crystals so as to change the composition of the residual gas out of the explosive gas range.
As described, most of chlorine in the crude chlorine gas is crystallized as the chlorine hydrate crystals and then the chlorine hydrate crystals are decomposed to obtain chlorine gas having high purity. When it is necessary to effectively crystallize chlorine in the crude chlorine gas as the chlorine hydrate crystals, it is preferable to carry out the step of form-ation of the chlorine hydrate crystals by multi-steps. The purpose can be at-tained by combining the first and second steps of formation of the chlorine hydrate crystals.
~, _ . .
, - ~8~922 That is, the crude chlorine gas is countercurrently contacted with the cooled transEer medium in the presence of water under about the atmospheric pressure whereby most of chlorine in the crude chlorine gas is crystallized to form the chlorine hydrate crystals in the first crystallization step and the residual chlorine gas and other gases, such as oxygen and hydrogen are taken out from the first crystallization step andthese gases are fed to the seconcl crystallization step. The chlorine partial pressure in the gases, is low whereby the gases are preferably slightly compressed. In the second crystallization step,the partial pressures of the bther gases such as oxygen and hydrogen beside chlorine in the crude chlorine gas are higher.
When the chlorine gas is crystallized as the chlorine hydrate crystals, the explosive gases may be generated as described above. Accordingly, the crude chlorine gas is fed into the cooled transfer medium to form the chlorine hydrate crystals.
The chlorine hydrate crystals crystallized in the first and second crystallization steps, are fed, with the thermal medium in the Eorm of a slurry, to the decomposition step of the chlorine - hydrate crystals.
Thus, the crude chlorine gas is cooled under about atmospheric pressure to crystallize most of chlorine as the chlorine hydrate crystals in the first crystallization step and the residual chlorine is cooled under the pressure slightly higher than 1 atm. in the second crystallization step, whereby chlorine in the crude chlorine gas can be substantially crystallized as the chlorine hydrate crystals in high efficiency.
The case using water as the transfer medium will be illustrated.
The advantages of the use of water as the transfer medium are as follows:
(1) Water can be the source of crystal water for forming the chlorine hydrate crystals.
g _ ,.
-~869;~2 (2) Water is less vaporizable and a large amount of water will not be incorporated in the chlorine gas when the chlorine hydrate crystals are decomposed.
(3) Water can be easily separated even though water is incorporated in chlorine gas.
(4) Chlorine is not substantially absorbed by water.
(5) Oxygen and hydrogen are not substantially absorbed by water.
The crude chlorine gas is contacted with a cold water so as to crystallize chlorine in the crude chlorine gas as the chlorine hydrate crystals. The other components of the crude chlorlne gas are in the gaseous state and are separated. The -chlorine hydrate crystals with water are removed as a slurry and the slurry is fed to the decomposition step of the chlorine hydrate crystals, wherein the pressure is lowered to lower than the decomposition pressure of the chlorine hydrate crystals so as to generate chlorine gas. The water is cooled by the endo-thermic decomposition of the chlorine hydrate crystals and is recycled to the step of formation of the chlorine hydrate crystals , so as to cool the crude chlorine gas. Thus, the chlorine gas having high purity can be obtained. In -this case, the cold - water can be advantageously maintained to the constant temperature in the presence of an ice. Strictly speaking, a small amount of chlorine gas in the crude chlorine gas is dissolved in water whereby chlorine water is formed.
When water is used as the transfer medium, the step of formation of chlorine hydrate crystals is a-t least two steps and the pressure in the second crystallization step is higher than ~ the pressure in the first crystallization step, it is preferable to lower the pressure applied to the slurry of the chlorine hydrat~
crystals discharged from the second crystalliza-tion step so as to discharge -the dissolved gas before the slurry is fed to the step ~8692Z
of decomposition of -the chlorine hydrate crystals because oxyyen may be dissolved in water. In particular, the slurry of the chlorlne hydrate crystals discharged from the second crystalliza-tion step is returned to the first crystallization step and it is fed to the decomposition step of the chlorine hydrate crystals.
The present invention will be further illustrated by the following Examples in conjunction with the accompanying drawings in which Figs. 1, 2 or 3 are flow diagrams of various embodiments of the method of the present invention.
Example 1:
A crude chlorine gas (CQ2 : 97 vol.%; 2 : 2.1 vol.%;
H2 : 0.2 vol.%; CO2 : 0.6 voI.%) obtained by an asbestos diaphragm type electrolysis of sodium chloride was fed into a crystallization vessel containing 5.0 m3 of water at -0.3C (ice:
35 wt.~) at a volume of 139 Nm and it was kept in 1 atm. The chlorine gas in the crude chlorine gas was crystalllzed and precipitated as CQ2-6H2O. The gas discharged from the water in the crystallization vessel and the residual water were discharged from the vessel.
The pressure in the crystallization vessel was then kept at 0.2 atm. so as to generate chlorine gas. The chlorine gas was dried and analyzed to find the chlorine concentration of 99.8% The recovery rate was 98.5%.
Example 2:
In the crystallization vessel (1) shown ln Figure 1, water at -0.3C (ice: 35 wt.%) was fed a-t a rate of 3.2 m /hr.
A crude chlorine gas (3) (CQ2 : 97 vol.%; 2 : 2.1 vol.%; H2 : 0.2 vol.%; CO2 : 0.6 vol.~) obtained by an asbestos diaphragm type electrolysis of sodium chloride was fed at a rate of i39 Nm3/hr.
and the pressure of the crystallization vessel (1) was kept in 1 atm. Most of chlorine gas in the crude chlorine gas was crystallized and precipitated as the hydrate of CQ2-6H2O. Ox~gen , gas, hydrogen gas and carbon dioxide gas (4) were discharged out of the vessel. The chlorine hydrate crystals were then removed as a slurry and was fed to a crystal decomposition vessel (2).
The pressure of the crystal decomposition vessel (2) was kept in 0.2 at~. to generate chlorine gas. Water was cooled by the endothermic reaction of the chlorine hydrate crystals and water was recycled to the crystallization vessel by a pump. Thus, in the recycle of water, a small amount of chlorine was dissolved in water. The chlorine gas (5) generated in the crystal decomposi-tion vessel was dried and analyzed to find the chlorine concentra~
tion of 99.8~. The recovery rate was 98%.
Example 3:
In the first crystallization vessel (1) shown in Figure 2, water at -0.3C (ice : 35 wt.%) was fed at a rate of 2.4 m3/hr. '~
A crude chlorine gas (3) (CQ2 : 97 vol.%; 2 : 2.1 vol.%; H2 : 0.2 vol.%; CO2 : 0.6 vol.%) obtained by an asbestos diaphragm type electrolysis of sodium chloride was fed at a rate of 139 Nm3/hr.
and the pressure of the first crystallization vessel (l) was kept in l atm. The chlorine gas was crystallized and precipitated as the hydrate of CQ2-6H2O. The gases (CQ2 : 35 vol.%; 2 : 48 vol.%;
H2 : 4 vol.%; CO2 : 13 vol.%) were discharged from the first crystallization vessel (l) and they were compressed to about ' 1.9 atm, and fed ,to the second crystallization vessel ~l').
In the second crystallization vessel, the water at -0.3C
(ice : 35 wt.%) was fed at a rate of 0.8 m3/hr. and the pressure of the vessel was kept in 1.7 atm. The gases were fed into the water in the second crystallization vessel from many distributed inlets. In the second crystallization vessel, the chlorine hydrate crystals CQ2-6H2O was crystallized. The slurry of the crystals was fed to the first crystallization vessel. Air was fed to dilute the gas discharge from the water in the second crystallization vessel and the diluted gas (4') was discharged out of the vessel.
-, 69;22 The chlorlne hydrate crystals collected inthe first crystallization vessel were fedto the crystal decomposition vessel (2)as the slurry.
The pressure of the crystal decomposition vessel was kep-t at 0.2 atm. so as to generate chlorine gas. Water was cooled by the endothermic decomposition reaction of the chlorine hydrate crystals and water was recycled to the first and second crystalliza-tion vessels (1), (l') by a pump. A small amount of chlorine was dissolved in the recycled water. The chlorine gas (5) generated in the crystal decomposition vessel was dried and analyzed to find the chlorine concentration of 99.8%. The recovery rate was 99.5%.
E ample 4 In the crystallization vessel (1) shown in Figure 3, water at 4C was fed at a rate of 2.4 m3/hr. A crude chlorine gas (3) (CQ2 : 97 vol.~; 2 : 2.1 vol.%; H2 : 0.2 vol.%; CO2 : 0.6 vol.%) obtained by an asbestos diaphragm type electrolysis of sodium chloride was fed at a rate of 139 Nm3/hr., and the gas was counter-currently contacted with water under the pressure of 1.5 atm. of 20- - the crystallization vessel. Most of chlorine in the crude chlorine gas was crystallized to precipitate the chlorine hydrate of CQ2-6H2O.
Oxygen hydrogen and carbon dioxide gases (4") were discharged out of the vessel. The chlorine hydrate crystals were then removed as a alurry and the slurry was fed to an aeration vessel (6) kept in 1 atm. wherein the aeration was carried out with the crude chlorine gas. From the vessel oxygen etc. dissolved in water was removed.
Thus, the chlorine hydrate crystals were taken out from .the vessel as a slurry with water, and the slurry was fed to a crystal decomposition vessel (2). The pressure of the crystal decomposition vessel was kept in 0.4 atm. so as to generate chlorine gas. Water was cooled by the endothermic reaction of the chlorine ,. '. ' '. ,.; ' . . .: :,. ' -69~Z
hydrate crystals and was recycled to the crystallization vessel by a pump. A small amount of chlorine was dissolved in the recycled water. The chlorine gas (5) generated in the crystal decomposition vessel was dried and analyzed to find the chlorine concentration of 99.8%. The recovery rate was 99~.
Example 5: -In accordance with the process of Example 2 a crude chlorine gas (CQ,2 : 97-5 vol.%; 2 : 2.2 vol.~; CO2 : 0.3 vol.~) which was obtained by the ion-exchange membrane type electrolysis of sodium chloride was purified. As the result, the chlorine concentration was 99.9% and the recovery rate was 98.5~.
. .. - . .. , ., . . , . ~ .:
. ' '' .. .: ... : ' . . ' ': , ;. . . .
The crude chlorine gas is contacted with a cold water so as to crystallize chlorine in the crude chlorine gas as the chlorine hydrate crystals. The other components of the crude chlorlne gas are in the gaseous state and are separated. The -chlorine hydrate crystals with water are removed as a slurry and the slurry is fed to the decomposition step of the chlorine hydrate crystals, wherein the pressure is lowered to lower than the decomposition pressure of the chlorine hydrate crystals so as to generate chlorine gas. The water is cooled by the endo-thermic decomposition of the chlorine hydrate crystals and is recycled to the step of formation of the chlorine hydrate crystals , so as to cool the crude chlorine gas. Thus, the chlorine gas having high purity can be obtained. In -this case, the cold - water can be advantageously maintained to the constant temperature in the presence of an ice. Strictly speaking, a small amount of chlorine gas in the crude chlorine gas is dissolved in water whereby chlorine water is formed.
When water is used as the transfer medium, the step of formation of chlorine hydrate crystals is a-t least two steps and the pressure in the second crystallization step is higher than ~ the pressure in the first crystallization step, it is preferable to lower the pressure applied to the slurry of the chlorine hydrat~
crystals discharged from the second crystalliza-tion step so as to discharge -the dissolved gas before the slurry is fed to the step ~8692Z
of decomposition of -the chlorine hydrate crystals because oxyyen may be dissolved in water. In particular, the slurry of the chlorlne hydrate crystals discharged from the second crystalliza-tion step is returned to the first crystallization step and it is fed to the decomposition step of the chlorine hydrate crystals.
The present invention will be further illustrated by the following Examples in conjunction with the accompanying drawings in which Figs. 1, 2 or 3 are flow diagrams of various embodiments of the method of the present invention.
Example 1:
A crude chlorine gas (CQ2 : 97 vol.%; 2 : 2.1 vol.%;
H2 : 0.2 vol.%; CO2 : 0.6 voI.%) obtained by an asbestos diaphragm type electrolysis of sodium chloride was fed into a crystallization vessel containing 5.0 m3 of water at -0.3C (ice:
35 wt.~) at a volume of 139 Nm and it was kept in 1 atm. The chlorine gas in the crude chlorine gas was crystalllzed and precipitated as CQ2-6H2O. The gas discharged from the water in the crystallization vessel and the residual water were discharged from the vessel.
The pressure in the crystallization vessel was then kept at 0.2 atm. so as to generate chlorine gas. The chlorine gas was dried and analyzed to find the chlorine concentration of 99.8% The recovery rate was 98.5%.
Example 2:
In the crystallization vessel (1) shown ln Figure 1, water at -0.3C (ice: 35 wt.%) was fed a-t a rate of 3.2 m /hr.
A crude chlorine gas (3) (CQ2 : 97 vol.%; 2 : 2.1 vol.%; H2 : 0.2 vol.%; CO2 : 0.6 vol.~) obtained by an asbestos diaphragm type electrolysis of sodium chloride was fed at a rate of i39 Nm3/hr.
and the pressure of the crystallization vessel (1) was kept in 1 atm. Most of chlorine gas in the crude chlorine gas was crystallized and precipitated as the hydrate of CQ2-6H2O. Ox~gen , gas, hydrogen gas and carbon dioxide gas (4) were discharged out of the vessel. The chlorine hydrate crystals were then removed as a slurry and was fed to a crystal decomposition vessel (2).
The pressure of the crystal decomposition vessel (2) was kept in 0.2 at~. to generate chlorine gas. Water was cooled by the endothermic reaction of the chlorine hydrate crystals and water was recycled to the crystallization vessel by a pump. Thus, in the recycle of water, a small amount of chlorine was dissolved in water. The chlorine gas (5) generated in the crystal decomposi-tion vessel was dried and analyzed to find the chlorine concentra~
tion of 99.8~. The recovery rate was 98%.
Example 3:
In the first crystallization vessel (1) shown in Figure 2, water at -0.3C (ice : 35 wt.%) was fed at a rate of 2.4 m3/hr. '~
A crude chlorine gas (3) (CQ2 : 97 vol.%; 2 : 2.1 vol.%; H2 : 0.2 vol.%; CO2 : 0.6 vol.%) obtained by an asbestos diaphragm type electrolysis of sodium chloride was fed at a rate of 139 Nm3/hr.
and the pressure of the first crystallization vessel (l) was kept in l atm. The chlorine gas was crystallized and precipitated as the hydrate of CQ2-6H2O. The gases (CQ2 : 35 vol.%; 2 : 48 vol.%;
H2 : 4 vol.%; CO2 : 13 vol.%) were discharged from the first crystallization vessel (l) and they were compressed to about ' 1.9 atm, and fed ,to the second crystallization vessel ~l').
In the second crystallization vessel, the water at -0.3C
(ice : 35 wt.%) was fed at a rate of 0.8 m3/hr. and the pressure of the vessel was kept in 1.7 atm. The gases were fed into the water in the second crystallization vessel from many distributed inlets. In the second crystallization vessel, the chlorine hydrate crystals CQ2-6H2O was crystallized. The slurry of the crystals was fed to the first crystallization vessel. Air was fed to dilute the gas discharge from the water in the second crystallization vessel and the diluted gas (4') was discharged out of the vessel.
-, 69;22 The chlorlne hydrate crystals collected inthe first crystallization vessel were fedto the crystal decomposition vessel (2)as the slurry.
The pressure of the crystal decomposition vessel was kep-t at 0.2 atm. so as to generate chlorine gas. Water was cooled by the endothermic decomposition reaction of the chlorine hydrate crystals and water was recycled to the first and second crystalliza-tion vessels (1), (l') by a pump. A small amount of chlorine was dissolved in the recycled water. The chlorine gas (5) generated in the crystal decomposition vessel was dried and analyzed to find the chlorine concentration of 99.8%. The recovery rate was 99.5%.
E ample 4 In the crystallization vessel (1) shown in Figure 3, water at 4C was fed at a rate of 2.4 m3/hr. A crude chlorine gas (3) (CQ2 : 97 vol.~; 2 : 2.1 vol.%; H2 : 0.2 vol.%; CO2 : 0.6 vol.%) obtained by an asbestos diaphragm type electrolysis of sodium chloride was fed at a rate of 139 Nm3/hr., and the gas was counter-currently contacted with water under the pressure of 1.5 atm. of 20- - the crystallization vessel. Most of chlorine in the crude chlorine gas was crystallized to precipitate the chlorine hydrate of CQ2-6H2O.
Oxygen hydrogen and carbon dioxide gases (4") were discharged out of the vessel. The chlorine hydrate crystals were then removed as a alurry and the slurry was fed to an aeration vessel (6) kept in 1 atm. wherein the aeration was carried out with the crude chlorine gas. From the vessel oxygen etc. dissolved in water was removed.
Thus, the chlorine hydrate crystals were taken out from .the vessel as a slurry with water, and the slurry was fed to a crystal decomposition vessel (2). The pressure of the crystal decomposition vessel was kept in 0.4 atm. so as to generate chlorine gas. Water was cooled by the endothermic reaction of the chlorine ,. '. ' '. ,.; ' . . .: :,. ' -69~Z
hydrate crystals and was recycled to the crystallization vessel by a pump. A small amount of chlorine was dissolved in the recycled water. The chlorine gas (5) generated in the crystal decomposition vessel was dried and analyzed to find the chlorine concentration of 99.8%. The recovery rate was 99~.
Example 5: -In accordance with the process of Example 2 a crude chlorine gas (CQ,2 : 97-5 vol.%; 2 : 2.2 vol.~; CO2 : 0.3 vol.~) which was obtained by the ion-exchange membrane type electrolysis of sodium chloride was purified. As the result, the chlorine concentration was 99.9% and the recovery rate was 98.5~.
. .. - . .. , ., . . , . ~ .:
. ' '' .. .: ... : ' . . ' ': , ;. . . .
Claims (10)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of purifying chlorine gas which comprises the steps of cooling a crude chlorine gas in the presence of water sufficient to form chlorine hydrate crystals and a heat transfer medium so as to crystallize chlorine in said crude chlorine gas as chlorine hydrate crystals, and separating the other components of said crude chlorine gas from said chlorine hydrate crystals, and then, decomposing said chlorine hydrate crystals by reducing the pressure to lower than the decomposition pressure to obtain purified chlorine gas.
2. The method of Claim 1 wherein said crude chlorine gas contains at least one of oxygen, hydrogen and carbon dioxide.
3. The method of Claim 1 wherein said crude chlorine gas is obtained by an electrolysis of an alkali metal chloride with a metallic electrode.
4. The method of Claim 1 wherein said chlorine hydrate crystals are C12.nH20 (n=5 to 8).
5. The method of Claim 1 wherein said crude chlorine gas is cooled under the conditions of temperature and pressure shown by the equation wherein 270° <T< 310°, for (PmmHg) and T(°K), whereby said chlorine hydrate crystals are formed.
6. The method of Claim 1 wherein after crystallization, said chlorine hydrate crystals are taken out as a slurry containing said heat transfer medium, said slurry is kept at a pressure lower than the decomposition pressure of chlorine hydrate crystals to generate chlorine gas, said heat transfer medium is cooled by the endothermic decomposition reaction of said chlorine hydrate crystals, and said cooled heat transfer medium is recycled to cool said crude chlorine gas.
7. The method of Claim 1 wherein said heat transfer medium is a liquid in the operation and is inert to chlorine.
8. The method of Claim 6 wherein said heat transfer medium is water.
9. The method of Claim 8 wherein said crystallization is performed in two steps, such that said crude chlorine gas is first cooled to -3 to 12°C by contacting it with cold water under about atmospheric pressure so as to crystallize a major portion of the chlorine in said crude chlorine gas as chlorine hydrate crystals, and the remaining crude chlorine gas is separately cooled to -3 to 12°C by contacting it with cold water under higher pressure so as to crystallize substantially the remaining chlorine in said remaining crude chlorine gas as chlorine hydrate crystals, and the combined chlorine hydrate crystals from said two steps are taken out as said slurry.
10. The method of Claim 1, wherein said heat transfer medium is selected from the group consisting of dichlorofluoro-methane, chlorodifluoromethane and water.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP106261/1976 | 1976-09-07 | ||
| JP10626176A JPS5331593A (en) | 1976-09-07 | 1976-09-07 | Purifying method for chlorine gas |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1086922A true CA1086922A (en) | 1980-10-07 |
Family
ID=14429145
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA286,119A Expired CA1086922A (en) | 1976-09-07 | 1977-09-06 | Purification of chlorine gas |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS5331593A (en) |
| AU (1) | AU511882B2 (en) |
| BR (1) | BR7705948A (en) |
| CA (1) | CA1086922A (en) |
| DE (1) | DE2740341A1 (en) |
| FR (1) | FR2392930A1 (en) |
| GB (1) | GB1545354A (en) |
| IT (1) | IT1086072B (en) |
| NL (1) | NL7709776A (en) |
| SE (1) | SE428465B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5985226A (en) * | 1998-01-07 | 1999-11-16 | Occidental Chemcial Corporation | Method of recovering chlorine from a gas mixture |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60193230A (en) * | 1984-03-15 | 1985-10-01 | Toshiba Corp | Method of assembling electrode of cathode-ray tube and apparatus therefor |
| NL1000578C1 (en) * | 1995-06-15 | 1996-02-06 | Heinrich Jozef Adrianus Van Ke | Apparatus and method for cleaning a gas or vapor stream. |
| DE102006024518A1 (en) * | 2006-05-23 | 2007-11-29 | Bayer Materialscience Ag | Process for the production of chlorine from hydrogen chloride and oxygen |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE45620C (en) * | Dr. CHR. heinzerling und Dr. J. schmid, Beide in Zürich | Process for the preparation of concentrated chlorine gas from dilute chlorine gas mixtures | ||
| US1723300A (en) * | 1925-03-31 | 1929-08-06 | Canadian Ind | Method of obtaining pure chlorine |
-
1976
- 1976-09-07 JP JP10626176A patent/JPS5331593A/en active Pending
-
1977
- 1977-09-05 FR FR7726848A patent/FR2392930A1/en active Granted
- 1977-09-05 AU AU28554/77A patent/AU511882B2/en not_active Expired
- 1977-09-06 SE SE7709995A patent/SE428465B/en unknown
- 1977-09-06 GB GB37227/77A patent/GB1545354A/en not_active Expired
- 1977-09-06 CA CA286,119A patent/CA1086922A/en not_active Expired
- 1977-09-06 NL NL7709776A patent/NL7709776A/en not_active Application Discontinuation
- 1977-09-06 BR BR7705948A patent/BR7705948A/en unknown
- 1977-09-07 DE DE19772740341 patent/DE2740341A1/en not_active Withdrawn
- 1977-09-07 IT IT27302/77A patent/IT1086072B/en active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5985226A (en) * | 1998-01-07 | 1999-11-16 | Occidental Chemcial Corporation | Method of recovering chlorine from a gas mixture |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5331593A (en) | 1978-03-24 |
| IT1086072B (en) | 1985-05-28 |
| FR2392930B1 (en) | 1983-07-08 |
| FR2392930A1 (en) | 1978-12-29 |
| NL7709776A (en) | 1978-03-09 |
| DE2740341A1 (en) | 1978-03-16 |
| AU511882B2 (en) | 1980-09-11 |
| SE428465B (en) | 1983-07-04 |
| GB1545354A (en) | 1979-05-10 |
| AU2855477A (en) | 1979-03-15 |
| SE7709995L (en) | 1978-03-08 |
| BR7705948A (en) | 1978-07-18 |
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