JPS59190202A - Manufacture of chlorine hydrate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to an improved method for producing chlorine hydrate, and more particularly to producing chlorine hydrate for use in zinc chloride secondary energy storage batteries that do not require cooling equipment. Regarding the method.

A secondary energy storage system of the type referred to herein (TatoEha, zinc chloride batch system or other suitable metal-halogen battery system) consists of three basic components: an electrode stack, an electrolyte circulation system, and a storage system. It is composed of Electrode stacks typically include a number of cells electrically coupled together in various series and parallel combinations to obtain the desired operating voltage and current at one battery terminal over the charge/discharge battery cycle. . Each cell consists of a positive and negative electrode, both in contact with an aqueous zinc chloride electrolyte.

The electrolyte circulation system operates to circulate the zinc chloride electrolyte from the reservoir through each cell in the electrode stack, removing the zinc and chloride electrolyte components as they are oxidized or reduced within the cells during battery cycling. Replenish when the time comes. In a hermetically sealed, self-retaining zinc chloride battery system, a storage system is used to store chlorine gas released from the cell during charging of the battery system and to subsequently return it to the cell during discharge of the pantry system. to hold. In such zinc chloride battery systems, chlorine gas is released from the positive electrode of the cell and stored in the form of chlorine hydrate. Chlorine hydrate is a solid and is produced by auxiliary storage systems in processes similar to frozen water processes in which chlorine is contained in ice crystals.

Regarding the general operation of a seeded zinc battery system, an electrolyte pump circulates an aqueous zinc chloride electrolyte from a reservoir to each of the positive 'm*' electrodes in the body. These chlorine electrodes are typically made of porous graphite, and the electrolyte passes through the pores of the chlorine electrode into the space between the chlorine electrode and the opposing negative or "zinc" electrode. The electrolyte then flows between the opposing electrodes or otherwise up the outside of the cell within the electrode stack and back into the electrolyte reservoir or sump.

During charging of a zinc cyclide battery system, zinc is deposited on the zinc electrode substrate and salt gas is released or generated at the chlorine electrode. The chlorine gas is collected in a suitable conduit and then mixed with the cooled liquid to form chlorine hydrate. A gas pump is typically used to draw chlorine gas from the electrode layer and mix it with a cooled liquid (ie, typically either a zinc chloride electrolyte or water). Chlorine hydrate deposits in the storage container until the battery system is discharged.

During the discharge of a zinc chloride battery system, chlorine hydrate is
It is decomposed by increasing the temperature, for example by circulating a hot liquid through a storage container. The chlorine gas regenerated by this is used in the electrolyte circulation support system,
There it is collected at the chlorine electrode and returned to the electrode stack via the chlorine electrode. At the same time, zinc metal is eluted from the zinc electrode substrate, and power is obtained from one terminal of the battery.

Further discussion of skidding and operation of zinc chloride paste systems can be found in the following patents: Symons U.S. Patent No. 3. ．． 713.888
No. Specification: Title of the invention “Electrical energy process using hydrated halogen”; Symons
U.S. Pat. No. 3,809,578@Specification: Title: "Process for the Production and Storage of Halogen Hydrates in Batteries"; U.S. Pat. No. 4,100. of Carr (0arr).
Roro No. 2 Specification: Title of the invention "<C-shaped bipolar electrode element and battery eA Jd body attached thereto" Such a system is also described in the report published by the patentee of the above patent, for example: ``Development of Zinc Chloride Batteries for Medicinal Applications''
of the Zinc-Chloride Eatl
ery for Utility Application
ns'), Interim Report
) EM-1417, May 1980; "Development of Zinc Chloride Battery for Practical Applications", Zhong 1 Zhao De Rebuttal EM
-1051+ In April 1979, the two parties joined the Electric Power Research Institute (t.
he Electric PowerResearch
It was prepared for ``In5titude'';
Knitted leaded electric engine unit J for four-seater electric vehicles ('Zinc-Ohlorj, de Elect
ric EngineUnit for Four-P
Assenger Electric Vehicle
'), 'Electric and Hybrid Vehicle Advancement $J (
'Electric And Hybrid Vehicle
le Progress'), April 1981, 5AFi reprint from Page 91 May 1981 (SAE
Reprint May 1981); and 19
Proceedings of the 60th Power Supply Symposium held in June 1982 (Pro
ceedingsof 30th Power 5ou
rces Symposium) published in ``
Recent Advances in Zinc Chloride Battery Technology
Advances Engineering Zinc-Chlori
The specific teachings of the references cited above are hereby incorporated by reference.

Over the years, extensive efforts have been made to advance the technology for producing norlambda hydrate. Indeed, these efforts have resulted in several inventions, some of which have already been patented and others currently under investigation.
Patent No. 3,713,888, which includes the following:
No. 6,809,578@specification; U.S. Pat.
No. 783,027, Title 2: "Apparatus and method for producing chlorine hydrate from high energy density battery electrolyte and chlorine"; U.S. Pat. No. 3,793,077 to Behling: Title of the invention: Title: “Battery Including Apparatus for Producing Halokane Hydrate”; U.S. Patent No. 6,814,6 to Bjorkm2Ln
No. 50 Specification Threat: Title of the Invention: "Filter/Storage for 'fii Energy Storage Apparatus'"; Bjorkman U.S. Pat. Bjorkman U.S. Pat. No. 3,840.6
Specification No. 50: Title of the invention "Stable Chlorine Hydrate"; U.S. Patent No. 3,907,592 to Symons
No. 3,908,001 Specification: Title of the invention “Halokene hydrate”; Simmons U.S. Patent No. 3,908,001 Specification: Title of the invention “Production of chlorine hydrate”; Simmons U.S. Patent No. 6, 96
No. 5,024 specification also: Title of invention "Halogen hydrate";
Simmons, U.S. Pat. No. 3,940,283: Title of the invention: "Halogen hydrates"; C!arr et al., U.S. Pat. “Operational Zinc-Chloride Battery Based on Water Storage”; Basing US Li5l Patent No. 4.115.52
Specification No. 9: Title of the invention “Production of halogen hydrate from halogen and finely divided aqueous droplets”;
U.S. Patent Application No. 310.627 (198
Application No. 357,742 (No. 198), filed October 13, 2013, entitled "Construction of Metal Halogen Battery with Improved Technology for Producing Halogen Hydrates");
Filed on June 12, 2013, title of invention: “Halokee 8 hydrate storage device for mobile zinc chloride battery system”;
U.S. Patent Application No. 668,892 (April 16, 1982)
Application No. 35'8,628, entitled "Multi-Stage Multi-Filk Hydrate Reservoir");
Application dated June 16, 19982, title of invention: "Metal halogen battery system with multiple nozzles for hydrates"
). The specific teachings of these references are incorporated herein by reference.

Generally speaking, it is desirable to acondense or otherwise generate concentrated chlorine hydrates to reduce the size and/or weight of the hydrate reservoir. This consideration is particularly important when zinc chloride batteries are used to power electric vehicles, where the size and weight of the hydrate reservoir have a significant effect on the operating range of electric vehicles. It will affect you. Although highly pressurized chlorine hydrates have been used in the past to reduce the size and weight of hydrate storage bodies, one of the primary techniques for increasing the density of chlorine hydrates is The solution is to employ filtration in the storage chamber.

An example of such a filtration technique is U.S. Patent No. 3,814,63.
No. 0 and U.S. Patent Application No. 3, (58
, No. 892.

The purpose of the filter in the reservoir is to separate the pressurable particulate chlorine hydrate from the liquid used in the hydrate production process. When chlorine hydrate enters the storage body, it is in the form of a dilute slurry, of which 6-7 percent is hydrate crystals. However, due to the amount of chlorine gas released during battery charging, it is impractical to store chlorine hydrate particulates within this dilute slurry. Thus, a filter is used to provide a hydrate condensation system in which as much excess liquid as possible is removed. Therefore, it can be appreciated that increasing the density of hydrate particles within the reservoir will result in reducing the size and weight of the battery system.

In a zinc chloride battery system with a capacity of 5 Q KWh, the practical standard for selling chlorine hydrate by filtration is approximately 0.15 gm of total stored chlorine and water.
~0.17 gut OL2. These standards are 0-3 when the hydrate consists of CL2.8H20.
3 gm CL2/g, and hydrate oL2・6H
20 should be compared with the maximum theoretical chlorine hydrate precision of O-4gm OL2/gm.

It is therefore a principal object of the present invention to provide a method for producing chlorine hydrates that closely approach the highest theoretical density criteria.

It is another object of the present invention to provide a method for producing highly concentrated chlorine "hydrates" without the need for a cooling system.

It is a further object of the present invention to provide a process for producing highly concentrated chlorine hydrates in which the heat of formation is directly rejected to the environment.

It is an additional object of the present invention to provide a method for producing highly concentrated chlorine hydrate in situ.

It is another object of the present invention to provide a process for producing highly concentrated chlorine hydrates that requires a relatively small hydrate storage volume.

It is yet another object to provide a method for producing highly concentrated chlorine hydrate as part of a method for charging a zinc chloride battery system p used to power an electric vehicle.

To achieve the above objects, the present invention provides a method for producing chlorine hydrates which generally comprises combining liquid chlorine with an aqueous liquid and removing the heat of formation of the hydrate. The method may also include the steps of mixing liquid chlorine with an aqueous liquid and cooling the chlorine hydrate to reduce pressure. However, according to the present invention, no cooling of the aqueous liquid is required as the heat of formation may be substantially released into the ambient temperature environment.

Additional advantages and features of the invention will become apparent from the following detailed description of the preferred embodiments, which refers to the following set of drawings.

FIG. 1 is a graph of an equilibrium diagram for a systematic description of chlorine and various chlorine hydrates.

FIG. 2 is a simplified, partially cross-sectional view of a chlorine hydrate storage vessel according to the invention.

In its relatively broad aspects, chlorine hydrates may be produced in accordance with the present invention by combining liquid chlorine with an aqueous liquid or by removing the heat of hydrate formation. Good too. The aqueous liquid may be any suitable water-based liquid that will facilitate the formation of chlorine hydrate. Therefore, while water is preferred as the aqueous liquid, other suitable water-based liquids may be used, such as zinc chloride electrolyte.

One of the main advantages of this chlorine hydrate production method is that previous methods require cooling the aqueous liquid to a temperature typically between -8°C and +6°C to form hydrates with chlorine. Unlike when it had to be produced in a gaseous state, it does not require any cooling. Therefore, the aqueous liquid may be combined with liquid chlorine at room or substantially ambient temperature.

It will be appreciated that when the method for producing chlorine hydrate according to the present invention is used as part of a method for charging a zinc chloride battery, the gaseous chlorine generated in the stack must first be converted to liquid chlorine. . Although the energy consumed in this conversion may at least partially offset the energy saved by removing the cooling equipment, the chlorine hydrate produced in accordance with the present invention is typically It is important to note that the chlorine aquarium produced and concentrated by filtration is also quite concentrated. For example, a duram of stored total chlorine and water
Experiments have shown that a chlorine hydrate density of 0.32 gm c:c,2 (where the hydrate consists of OL, .8.4 H2O) is obtained. Therefore, another advantage of the present invention is that it reduces the size and weight of the hydrate reservoir. This consideration is, of course, very important when zinc chloride batteries are used to power vehicles. A relatively small and light hydrate storage body not only increases the operating range of electric vehicles, but also allows zinc chloride batteries to be conveniently used in all electric vehicles of relatively compact dimensions.

Another advantage of the present invention is that chlorine hydrate is produced "in situ". That is, the chlorine hydrate may be formed in the same vessel or container in which liquid chlorine and aqueous liquid are combined.

In conventional hydrate production processes, where chlorine hydrate is formed in a pump or conduit and transported to a storage room, this conduit becomes clogged with hydrate during the latter part of the battery charging process. There was a tendency to be disturbed. Because the chlorine hydrate is formed in the same container where the liquid chlorine and the aqueous liquid are combined, there is no need to transport the hydrate to other rooms, thereby eliminating the need to transport the hydrate in the conduits used to transport the hydrate. Any possibility of interference that might otherwise occur is eliminated.

A further advantage of the present invention is that the heat of hydrate formation may be transferred to the ambient temperature or to a substantially ambient temperature environment outside the vessel in which the hydrate is formed. Therefore, the need to maintain the chlorine hydrate at a cool temperature by insulating the hydrate reservoir from the entire environment is greatly reduced or eliminated. It is therefore advisable to configure the storage chamber in such a way that it is capable of releasing heat into the entire environment.

Although it should be appreciated that in appropriate applications it may be advisable to provide some cooling during or after chlorine hydrate formation to assist in removing the heat of hydrate formation.
It should be understood that this step is not essential to practicing the entire invention. Similarly, although it may be reasonable to control the temperature of the aqueous liquid before or during the formation of chlorine hydrate, such as by cooling the aqueous liquid until a predetermined temperature and pressure is reached, this step is not essential. Anything that is not essential to the carrying out of the invention should be understood.

An additional step to the present invention that is preferred, but under appropriate circumstances may not be essential, is to mix the liquid chlorine with an all-aqueous liquid. This mixing may be accomplished by a variety of suitable means, such as stirring, stirring, shaking, blenaing, etc.
, intermingling, or otherwise by bringing liquid chlorine and aqueous liquid into intimate association or intimate contact. Preferably, the mixing step should occur concomitantly with the step of removing the heat of formation of the hydrate. Indeed, the steps of combining liquid chlorine with an all-aqueous liquid (e.g., by adding it to all containers of these two components), mixing these two components together, and removing the heat of formation of the hydrate are all incidental. It can happen. However, other suitable timing relationships may be provided depending on the appropriate application.

Referring to FIG. 1, an equilibrium diagram for the systematic composition of chlorine and various chlorine hydrates is shown.

The curves contained in this equilibrium diagram are used to illustrate the pressure and temperature relationship relevant to the present invention. For example “A”
The curve labeled represents the total chlorine vapor pressure above the chlorine liquid with respect to temperature. Curve 'A''' indicates that when liquid chlorine is added or otherwise introduced into the vessel in which the hydrate is to be produced, it is under relatively high pressure.
indicates.

Assuming that the vessel is at a pressure lower than that of the liquid chlorine before being introduced into the vessel, a portion of the liquid chlorine will evaporate as it is introduced into the vessel. This evaporation continues until the pressure within the vessel rises rapidly to a certain level, depending on the amount of liquid chlorine supplied to the vessel. For example, the pressure inside the container is typically between 70 and 85 p, s, ■,
during which a substantial portion of the liquid chlorine supplied remains in its initial liquefied state.

The "B" to "B" curves represent the temperatures and pressures required to produce chlorine water in all the various aqueous liquids.

Curve “B” represents chlorine water products generated with water,
Curve "c" to ff EI+, on the other hand, represents the chlorine hydrate formed with the mixture of water and zinc chloride electrolyte. Thus, for example, curve "C" represents chlorine hydrate formed with a 16% concentration of zinc chloride in water, and the unidirectional line N
ET+ stands for chlorine hydrate formed with 40% zinc chloride in water.

Therefore, curve ``B'' shows that chlorine hydrate may be formed at low pressures and temperatures that are also moderately low.
It is further understood that chlorine hydrates may be formed at high pressures and moderately high temperatures. After the chlorine hydrate has been formed according to the method, the pressure within the vessel may be reduced by providing some cooling to the chlorine hydrate, which cooling may be accomplished by any conventional means,
It may be provided, for example, by heat exchange with a cold or chilled liquid (i.e. water).

It should be noted that it is a good idea to control the relative amounts of liquid chlorine and aqueous liquid added to the vessel to convert as much of these components into chlorine aqueous products as possible. Theoretically, liquid chlorine and aqueous liquid should be in predetermined amounts to ensure complete conversion to chlorine hydrate. However, as a practical matter, if these amounts cannot be precisely controlled, or if the liquid chlorine and aqueous liquid are not well mixed, complete conversion may not occur and some free liquid chlorine and/or Some free aqueous liquid will remain.

Thus, for example, some liquid chlorine remains at the bottom of the vessel after the hydrate formation process is generally completed, a very concentrated chlorine hydrate adjacent to this liquid chlorine, and a relatively less concentrated chlorine near the top of the vessel. A situation will arise where there is an aqueduct, aqueous liquid trapped between the layers of the hydrate, and some gaseous chlorine above the hydrate at the top of the vessel.

Since the pressure inside the vessel at the end of the chlorine hydrate formation process depends on the temperature inside the vessel, this pressure is typically between 50 and 7
It should be between 0 P and S2.

When this process is employed in a zinc chloride battery, this pressure rapidly (
It should be noted that it decreases (i.e. within the first 10 discharges). Additionally, this pressure may be reduced by cooling after the hydrate is formed. If necessary, cooling may be provided sufficiently sufficient to reduce the pressure within the container to ambient pressure.

Furthermore, although total chlorine hydrate formation at typical room temperatures does not require any cooling equipment, the surrounding environmental temperature may be sufficiently high (i.e., generally above 28.6°C) that hydrate formation It should be understood that additional cooling or refrigeration equipment may be required to remove the heat generated. However, such cooling or refrigeration schemes also suffer from the disadvantages required to chill aqueous liquids to temperatures typically between -8°C and +6°C, as in conventional chlorine hydrate production processes. Substantially less.

Returning to the description of the storage container or container utilized in carrying out the invention, it should be noted that this container was constructed for experimental and demonstrative purposes and that the invention is not limited to any particular container shape or design. You should understand that. Thus, for example, although the containers described herein are cylindrical, the containers may also be spherical in shape or otherwise.

Referring to FIG. 2, a simplified diagram of a chlorine hydrate storage vessel 10 according to the present invention is shown. The storage container 10 is generally a glass tube 1
2, a plastic top cover 14, and a plastic bottom plate 16.

Top cover 14 is attached to tube 12 by a pair of tightening rings 20-22 and a number of circumferentially arranged weld bolts 24 and nuts 26. The fibrous grommet '17 of the separation ring is inserted between the tightening ring 22 and the glass tube 120 in a conventional manner. Bottom plate 16 is also attached to tube 12 in the same manner as described above with respect to top cover 14. A pair of gaskets are provided to facilitate fluid-tight seals between tube 12 and top cover 14 and between tube 12 and bottom plate 16).
gaskete) 23-30 were prepared.

The top cover 14 is provided with two holes 32-34 to accommodate the tube 12,
This allows access to an internal chamber 36 partitioned by the top cover 14 and the bottom plate 16. For example, hole 32 may be used to introduce or add aqueous liquid to chamber 36, and hole 34 may be used to introduce or add liquid chlorine to chamber 36. To seal the hole 32 and allow pressure to be applied to the chamber 36 during the hydrate formation process, a plastic plug 38 is inserted into the hole. Similarly,
The hole 34 is connected to the valve 4 which is mounted on the storage container 1o through a screw connection.
Sealed by 0.

To introduce liquid chlorine into chamber 36, a suitable liquid chlorine source, such as a conventional chlorine cylinder 42 total coupling/7" 44
Connect to the valve from K. The liquid, chlorine, is then released into the chamber 36 by opening both the chlorine cylinder valve 46 and the storage vessel valve 4o.
may be supplied to It should be understood that when the present invention is practiced in a zinc chloride battery, the source of liquid chlorine may be obtained from the battery stack as well as from the chlorine cylinder. .

The storage container 10 can be made of any suitable material that is chemically resistant or inert to the chemical entities with which it comes into contact, such as liquid/gaseous chlorine and aqueous liquids. It may be made of matter. Thus, for example, top cover 14, bottom plate 16, plug 38, etc. may be made of a variety of materials. These materials may include, without limitation, Teflon (Trademark of DuPont), Kynar, Penn
walt) trademark, and General Tire & Rubber Corp.
Voltron (Bol) manufactured by Corp.
tron) Polyvinyl chloride Kanakuramu. Other examples of suitable materials are previously identified in the 1980 ``Development of Zinc Chloride Batteries for Practical Use'' (Developemsn.
to of the Zinc-Ohloriae Ba
tleryFor Utility Application
ions”) = can be found in comic books.

As for the tube 12, it may also be made entirely or in part of one of the above-mentioned materials. However, in one form of the invention, the tube 12 is a chamber. It should be noted that the storage container 1D should be constructed such that it has the ability to dissipate heat from 36 to the environment.
It may also be noted that it includes a number of holes that facilitate the removal of heat from the chamber 36.

Additionally, gaskets 28 and 30 may be made of any suitable sealing material that is also chemically resistant or inert to the chemical entity with which it comes into contact. Examples of such materials are polytetrafluoroethylene and VitOn
It is a fluoroelastomer. Other examples of suitable materials were previously identified in the 1980 Development of Zinc Chloride Batteries for Practical Use.
e Zinc-Chloride Battery Fo
r Utility Applications”) report.

In one form of the invention, the aqueous liquid is added to the top storage vessel 10 prior to adding liquid chlorine. The aqueous liquid may be added to some suitable level, such as the level indicated by reference number 50. Furthermore, the plug 38 is missing and the hole 32 is
It may be advantageous to expel all or substantially all the air from the chamber for three days before sealing it.

Preferably, this purging is accomplished by replacing the air in the gas space of chamber 36 with gaseous chlorine.

When valves 40 and 46 are opened, a portion of the liquid chlorine supplied to chamber 36 evaporates. This evaporation is an endothermic reaction, and the heat of evaporation of chlorine at atmospheric pressure is -4.8 Kcal/mole. This provides some cooling in chamber 36. However, this cooling is reduced to 18.6 KO at atmospheric pressure.
It is compensated by the heat of formation of hydrate, which is al/molθ. The heat of formation of this hydrate is readily removed from the chamber 36 through the glass tube 12 to the room temperature environment surrounding the storage vessel 10.

[Brief explanation of drawings]

Figure 1 shows the equilibrium chlorine vapor pressure of chlorine hydrate. Figure 2 shows a chlorine hydrate storage vessel. 12...Glass tube, 14...Top plastic cover, 16...Bottom plate, 20.22...Tightening ring, 24
... Zaruto, 26... Nut, 27... Packing, 28° 30... Gasket, 32.34... Hole,
38...Plastic stopper, 40...Valve, 42...
Chlorine cylinder, 44...coupling, 46...valve. Agent: Akira Asamura = Ezohi;, 已. Two =:;;・Sat・

Claims (1)

[Claims] (1) A method for producing chlorine hydrate, which method comprises the steps of: combining liquid chlorine with an aqueous liquid; and removing heat of hydrate formation. (2) The method according to Item 1 of Special Proposal 1, which includes the step of mixing liquid chlorine with an aqueous liquid. (3) The method according to claim 2, wherein the mixing step occurs concomitantly with the step of removing the heat of hydrate formation. (4) The method of claim 1, wherein a predetermined amount of liquid chlorine is mixed with a predetermined amount of an aqueous liquid. (5) The method of claim 2, wherein the heat of hydrate formation is removed by providing a substantially ambient temperature atmosphere. (6) The method according to claim 6, wherein the aqueous liquid is water. (7) The method according to claim 3, wherein the aqueous liquid is an aqueous electrolyte. (8) A method for producing chlorine hydrate, which comprises: preparing a container; adding a predetermined amount of aqueous liquid to the container; adding a predetermined amount of liquid chlorine to the container; and generating heat of hydrate formation. The above method comprising the step of removing. (9) The method according to claim 8, wherein an aqueous liquid is added to the container while liquid chlorine is added to the container. 00) The method of claim 8, further comprising the step of mixing liquid chlorine with the water injection liquid. 1) A method according to claim 10, wherein the mixing step occurs concomitantly with the step of removing the heat of hydrate formation. 12. The method of claim 10, further comprising the step of purging substantially all of the air from the container before adding liquid chlorine to the container. 03) Claim 8 characterized in that the heat generated is produced by providing a substantially ambient temperature associated with the container and by making the container from a material capable of emitting heat to the atmosphere. Method described. 9. The method of claim 8, wherein the steps of adding liquid chlorine to the vessel, adding an aqueous liquid to the vessel, and mixing the liquid chlorine with the aqueous liquid are all concomitant. θ5) The method of claim 8, wherein the method of producing chlorine hydrate forms part of a method of charging a zinc chloride battery. 17. The method of claim 16, comprising the step of: 0[i) cooling the chlorine hydrate so that the pressure inside the container is reduced. 07) The method of Scope of Merger Requirements paragraph 8, further comprising the step of controlling the temperature of the aqueous liquid before it is combined with liquid chlorine. u8) The method according to claim 8 of Patent No. 8fj, wherein the aqueous liquid or water is used. (19) The method according to claim 8, wherein the aqueous liquid is an aqueous electrolyte. C7 cut Zinc chloride batch IJ held in electric car
- A method for producing chlorine hydrate as part of a method for producing light, the method comprising: providing a container capable of maintaining normal pressure; mixing liquid chlorine with an aqueous liquid in the container; The above method comprising the step of removing the heat of product formation. The method of claim 20 of the patent, claim 20, comprising the step of cooling the chlorine hydrate such that the pressure inside the container is reduced.