JP2014070006A - Method of producing hydrochloric acid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing hydrochloric acid which suppresses rise in the temperature of a reaction system by a simpler procedure.SOLUTION: Hydrogen gas and chlorine gas are irradiated with light in the presence of hydrochloric acid gas, and hydrogen gas and chlorine gas react with each other to generate hydrochloric acid gas.

Description

  The present invention relates to a hydrogen chloride production method for producing hydrogen chloride by reacting hydrogen gas and chlorine gas.

  Hydrogen chloride is used for an etching gas for dry etching of a silicon semiconductor and for cleaning a silicon wafer growth furnace. Furthermore, in recent years, it is also used for silicon carbide, and its use in the semiconductor field is expanding. In the semiconductor field, mixing of impurities greatly reduces the yield, so it must be avoided most in each process, and high purity is required for all compounds used in the process. Furthermore, it must be manufactured at low cost.

  As a method of obtaining hydrogen chloride by reacting hydrogen and chlorine, there is a method of directly producing hydrogen chloride by burning chlorine in hydrogen as shown in the following formula.

H ₂ + Cl ₂ → 2HCl + 184.7 kJ
Since the reaction does not proceed by simply mixing hydrogen and chlorine, it is necessary to heat with a combustion burner or the like in order to proceed with this reaction, and the reaction temperature becomes as high as about 2500 ° C. Further, at such a high temperature, the reaction is not completed due to chemical equilibrium, and when hydrogen and chlorine are reacted in an equimolar ratio, about 2% of the added chlorine remains unreacted.

  The hydrochloric acid synthesizer described in Patent Document 1 includes a cooling unit that cools at least one of hydrogen gas and chlorine gas before the reaction. The synthesis method described in Patent Document 1 sets the supply amount of hydrogen gas to 1.2 to 1.5 times the theoretically required supply amount.

  In order to cool a high-temperature reaction product gas with a capacitor, it is necessary to improve the heat resistance of the material constituting the capacitor or to improve the configuration of the capacitor.

  Since it is difficult to improve the capacitor including the material, a method in which a high-temperature reaction product gas is directly absorbed in water and once recovered as hydrochloric acid is used. In order to separate hydrogen chloride from this hydrochloric acid, for example, as described in Patent Document 2, distillation is performed in the presence of a salt having a salting-out effect.

JP-A-5-105408 JP 2001-192202 A

  When separating hydrogen chloride from hydrochloric acid by distillation, since hydrogen chloride and water azeotrope, it is necessary to dehydrate from the azeotropic mixture obtained by distillation using a dehydrating agent such as calcium chloride, magnesium chloride or sulfuric acid. It becomes. Only a production method with low energy efficiency in which hydrogen chloride gas as a reaction product is recovered as hydrochloric acid and then distilled and dehydrated from hydrochloric acid to obtain hydrogen chloride gas has been put into practical use.

  An object of the present invention is to provide a method for producing hydrogen chloride in which the temperature rise of the reaction system is suppressed by a simpler procedure.

  The present invention is a method for producing hydrogen chloride, which comprises irradiating hydrogen gas and chlorine gas with light in the presence of hydrogen chloride gas and reacting the hydrogen gas and chlorine gas to produce hydrogen chloride gas.

The present invention also includes a mixing step of mixing hydrogen gas, chlorine gas, and hydrogen chloride gas to obtain a mixed gas;
And a light irradiation step of generating hydrogen chloride gas by irradiating the mixed gas with light and reacting hydrogen gas and chlorine gas contained in the mixed gas.

The present invention also includes a supply step of continuously supplying hydrogen gas, chlorine gas, and hydrogen chloride gas to the reactor,
And a light irradiation step of generating hydrogen chloride gas by irradiating the hydrogen gas and chlorine gas supplied to the reactor with light in the presence of hydrogen chloride gas and reacting the hydrogen gas and chlorine gas with each other. This is a method for producing hydrogen chloride.

  In addition, the present invention is characterized in that the number of moles of hydrogen chloride gas at the time of starting the light irradiation is at least five times the smaller number of moles of hydrogen gas and chlorine gas.

  Further, the present invention is characterized in that the number of moles of hydrogen gas at the time of starting light irradiation is less than the number of moles of chlorine gas.

  Further, the present invention is characterized in that the wavelength of light applied to the hydrogen gas and the chlorine gas is 250 to 450 nm.

  According to the present invention, hydrogen gas and chlorine gas are irradiated with light in the presence of hydrogen chloride gas, and the hydrogen gas and chlorine gas are reacted to generate hydrogen chloride gas.

  Further, according to the present invention, in the mixing step, hydrogen gas, chlorine gas, and hydrogen chloride gas are mixed to obtain a mixed gas, and then in the light irradiation step, the mixed gas is irradiated with light and is contained in the mixed gas. Hydrogen gas and chlorine gas are reacted to generate hydrogen chloride gas.

  Further, according to the present invention, hydrogen gas, chlorine gas, and hydrogen chloride gas are continuously supplied to the reactor in the supply step, respectively, and hydrogen gas and chlorine gas supplied to the reactor are supplied to the reactor in the light irradiation step. Irradiation with light in the presence of hydrogen chloride gas causes hydrogen gas and chlorine gas to react to produce hydrogen chloride gas.

  Reaction heat generated by the reaction between hydrogen gas and chlorine gas is absorbed by hydrogen chloride gas, and the temperature rise is suppressed. Since hydrogen chloride gas is a reaction product, it does not need to be separated after the reaction.

  By coexisting hydrogen chloride gas in this way, the temperature rise of the reaction system can be suppressed with a simpler procedure.

  Further, according to the present invention, the number of moles of hydrogen chloride gas at the time of starting light irradiation is set to 5 times or more of the smaller number of moles of the number of moles of hydrogen gas and the number of moles of chlorine gas. The temperature in the reaction system due to heat can be suppressed to 800 ° C. or less.

  According to the present invention, the number of moles of hydrogen gas at the time when light irradiation is started is made larger than the number of moles of chlorine gas. After the reaction, a mixture further containing unreacted hydrogen gas is obtained in the hydrogen chloride gas which is a reaction product and the hydrogen chloride gas supplied as a raw material, but when hydrogen chloride is liquefied, the hydrogen gas is converted into a gas phase. And the removed hydrogen gas can be reused as a raw material gas.

  Moreover, according to this invention, a chlorine radical can be efficiently produced | generated from a chlorine molecule by irradiating the light whose wavelength is 250-450 nm to hydrogen gas and chlorine gas.

It is process drawing which shows the example of the manufacturing method of hydrogen chloride gas. It is the schematic which shows the structure of the manufacturing apparatus 1 of the hydrogen chloride for implementing this invention.

A mixed gas of hydrogen gas and chlorine gas is stable at room temperature in a dark place, but the reaction proceeds explosively by heating or irradiation with light such as ultraviolet rays. By utilizing such a reaction, a high-purity hydrogen chloride gas can be obtained in large quantities at a time by using a high-purity hydrogen gas and a high-purity chlorine gas as raw materials.
Initiation reaction Cl ₂ + Light energy → 2Cl (radical)
Chain reaction H ₂ + Cl (radical) → HCl + H (radical)
Cl ₂ + H (radical) → HCl + Cl (radical)

  In the initiation reaction, chlorine molecules receive light energy and cleave into chlorine radicals. Chlorine radicals react with hydrogen molecules to produce hydrogen chloride and hydrogen radicals. This hydrogen radical reacts with the chlorine molecule to produce hydrogen chloride and regenerate the chlorine radical. In this way, the reaction is chained from the first generated chlorine radical.

  In the reaction for directly producing hydrogen chloride from hydrogen gas and chlorine gas as described above, since the reaction temperature is as high as 2500 ° C., cooling is necessary, and industrially, hydrogen chloride which is a reaction product. A production method in which gas is dissolved and recovered as hydrochloric acid once is used. If the final target is hydrochloric acid, there is no problem. However, in order to recover hydrogen chloride gas, it is necessary to separate the hydrogen chloride gas from hydrochloric acid, and the energy efficiency is extremely poor.

  In any case, in order to suppress the temperature rise of the reaction system, a substance that absorbs reaction heat other than water must be added to the reaction system, and the added substance becomes an impurity after the completion of the reaction. The operation of separating the reaction product and hydrogen chloride is essential.

  In view of such a situation, the inventors of the present application, as a result of intensive studies, are reaction products as additive substances that can be added to the reaction system to complete the reaction and suppress an increase in the reaction temperature. We have found that hydrogen chloride gas is preferred.

  When hydrogen gas and chlorine gas are reacted in the presence of hydrogen chloride gas, reaction heat is absorbed by hydrogen chloride gas, and the temperature of the reaction system can be suppressed to a temperature of, for example, 800 ° C. or less. Since hydrogen chloride gas is a reaction product, it does not become an impurity even if it is added to the reaction system, and it is not necessary to separate the hydrogen chloride gas generated by the reaction from the hydrogen chloride gas as an additive.

  The present invention is characterized in that, in the presence of hydrogen chloride gas, the raw material hydrogen gas and chlorine gas are irradiated with light, and the hydrogen gas and chlorine gas are reacted to generate hydrogen chloride gas.

  When the reaction between hydrogen gas and chlorine gas is initiated by light irradiation, the reaction temperature immediately rises. Therefore, in the presence of hydrogen chloride gas, the hydrogen gas and chlorine gas are irradiated with light in advance. To start the reaction. Therefore, in the production method of the present invention, any procedure may be used as long as light irradiation is performed in the presence of hydrogen chloride gas. For example, hydrogen gas, chlorine gas, and hydrogen chloride gas may be mixed in advance to generate a mixed gas, and the generated mixed gas may be irradiated with light. In a state where the hydrogen chloride gas is irradiated with light, Chlorine gas may be supplied, and light may be irradiated while continuously supplying hydrogen gas, chlorine gas, and hydrogen chloride gas to the reactor.

  The mixing ratio of hydrogen gas, chlorine gas and hydrogen chloride gas can be changed as appropriate, but when the reaction is completed, in order to keep the reaction temperature at 800 ° C. or lower, preferably 500 ° C. or lower, light irradiation is performed. Hydrogen chloride gas is mixed so that the number of moles of hydrogen chloride gas is 5 times or more, preferably 8 times or more with respect to the smaller number of moles of hydrogen gas and chlorine gas at the time of starting. Is preferred.

  When the number of moles of hydrogen chloride gas is less than 5 times, the effect of suppressing the reaction temperature is lowered. In addition, if the number of moles of hydrogen chloride gas is increased excessively to several tens of times, hydrogen chloride generated per reaction volume and reaction time decreases, which is not preferable.

  Regarding the mixing ratio of hydrogen gas and chlorine gas in the source gas, the ratio of the number of moles of hydrogen gas to the number of moles of chlorine gas (number of moles of hydrogen gas / number of moles of chlorine gas) may be 1. The number of moles / number of moles of chlorine gas may be less than 1 or greater than 1.

  When the number of moles of hydrogen gas / number of moles of chlorine gas is less than 1, a mixture of hydrogen chloride gas as a reaction product and unreacted chlorine gas is obtained after light irradiation. On the other hand, when the number of moles of hydrogen gas / number of moles of chlorine gas is greater than 1, a mixture of hydrogen chloride gas as a reaction product and unreacted hydrogen gas is obtained after irradiation with light. In either case, high purity hydrogen chloride gas can be obtained by liquefying the obtained mixture and performing distillation.

  When the number of moles of hydrogen gas / number of moles of chlorine gas is greater than 1, hydrogen chloride is liquefied by compressing the mixture obtained after the reaction, but hydrogen is not liquefied but remains as hydrogen gas. This hydrogen gas contains a small amount of hydrogen chloride and can be reused as a raw material gas. By reusing such raw material gas, hydrogen chloride gas can be obtained in substantially 100% yield from the raw material hydrogen gas and chlorine gas.

  When the number of moles of hydrogen gas / number of moles of chlorine gas is larger than 1, preferably 5 or less (5 times mole or less), more preferably 3 or less (3 times mole or less), it is obtained after the reaction. Hydrogen chloride can be liquefied efficiently from the mixture.

  As described above, according to the present invention, since the hydrogen gas and the chlorine gas can be reacted in the presence of hydrogen chloride gas, the treatment method may be a batch method or a continuous method. FIG. 1 is a process diagram showing an example of a method for producing hydrogen chloride gas.

  As shown in FIG. 1 (a), in the case of a batch system, hydrogen gas, chlorine gas, and hydrogen chloride gas as raw materials are provided in a reaction vessel that is at least partially transparent to the light irradiated for starting the reaction. Is mixed in advance (step A1 mixing step), and the reaction vessel is irradiated with light from a light source installed outside the reaction vessel to react the source gas in the reaction vessel (step A2 light irradiation step). ). After completion of the reaction, a mixture of the hydrogen chloride gas contained in the reaction product hydrogen chloride gas and the raw material mixed gas and the unreacted raw material if unreacted raw material remains, is added to the reaction vessel. To obtain hydrogen chloride gas. In the case of a batch system, the temperature in the reaction vessel rises as the reaction starts, and the pressure of the enclosed gas rises. Therefore, it is preferable to use a pressure vessel for the reaction vessel.

  As shown in FIG. 1B, in the case of the continuous system, hydrogen gas, chlorine gas, and hydrogen chloride gas are continuously supplied from the supply pipe to the reaction vessel (step B1 supply step), and the reaction vessel is irradiated by light irradiation. In the case where hydrogen gas and chlorine gas are reacted in the presence of hydrogen chloride gas (step B2 light irradiation process), and there are unreacted raw materials and hydrogen chloride gas which is a reaction product and supplied hydrogen chloride gas Continuously removes the mixture with the unreacted raw material from the reaction vessel.

  Adjust the position of the supply port of each gas into the reaction vessel, the inflow direction of each gas supplied into the reaction vessel, etc. as appropriate so that the gases are not unevenly distributed in the reaction vessel. It is preferable to supply each gas so that it becomes. For example, it is preferable to supply each supplied gas so that the flow is in a turbulent state in the reactor, and the inflow direction of each gas is preferably a direction in which vortex flow is generated in the reaction vessel. .

  FIG. 2 is a schematic diagram showing the configuration of the hydrogen chloride production apparatus 1 for carrying out the present invention. The hydrogen chloride production apparatus 1 has a photoreactor 2, a cooler 3, a compressor 4 and a pump 5. Hydrogen gas, chlorine gas, and hydrogen chloride gas as raw materials are supplied to the photoreactor 2, and light is irradiated in the presence of hydrogen chloride gas in the photoreactor 2 to react the hydrogen gas and the chlorine gas, A mixture of hydrogen chloride gas as the reaction product and the supplied hydrogen chloride gas and unreacted raw material is introduced into the cooler 3 when there is unreacted raw material. The mixture is cooled to about 100 to 200 ° C. by the cooler 3, a part is reused as a raw material gas, and the remaining part is compressed by the compressor 4 to be obtained as liquefied hydrogen chloride. When the number of moles of hydrogen gas / number of moles of chlorine gas is greater than 1 as the composition of the raw material, when compressed by the compressor 4, hydrogen chloride is liquefied and the hydrogen contained in the mixture remains gas. Thus, hydrogen chloride containing no hydrogen can be obtained.

  In the reaction of the photoreactor 2, reaction by-products and the like are not generated, and therefore the mixture obtained after the reaction does not include substances that become impurities other than the raw material composition. Therefore, when a part of the mixture is reused as the raw material gas, a separation operation for removing impurities is unnecessary, and a part of the mixture derived from the cooler 3 is supplied to the raw material using the pump 5. Just restore it.

  In addition, the mixture derived from the photoreactor 2 can be cooled by the cooler 3 until it is liquefied to obtain liquefied hydrogen chloride. In this case, the compressor 4 is unnecessary. In addition, once liquefied hydrogen chloride can be reused as a raw material.

  As described above, in the hydrogen chloride production reaction in the present invention, the reaction of producing chlorine radicals by light irradiation is rate-limiting, so the reaction rate of the entire production reaction is not greatly influenced by pressure. Therefore, there is little need to increase the pressure in the photoreactor 2, and the pressure is preferably 1 MPa or less, although it depends on the supply temperature of the raw material chlorine. In addition, since chlorine liquefies at 20 ° C. at a pressure of 0.67 MPa or more, it takes time until the chlorine supplied to the photoreactor 2 is gasified in the photoreactor 2. It is necessary to increase the residence time in When liquefied chlorine is used, it is not necessary to lengthen the residence time by heating the liquefied chlorine in advance and supplying it to the photoreactor 2 as chlorine gas. It can be appropriately selected depending on the specifications.

  If the pressure is lower than 0.03 MPa, the partial pressure of hydrogen gas and chlorine gas in the photoreactor 2 is lowered, the collision frequency between each molecule and radical is lowered, and the reaction rate is lowered. The productivity per reaction time is reduced per 2 volumes.

  The wavelength of the light irradiated for initiating the reaction may be a wavelength having an energy that allows the irradiated light to be absorbed by the chlorine molecule and break the bond between the chlorine atom and the chlorine atom, and has a wavelength band of 250 to 450 nm. Is preferred. Since light in this wavelength band is also included in sunlight, the reaction can be initiated by irradiating the source gas with sunlight.

  As a light source for irradiating light in this wavelength band, a high-pressure mercury lamp is often used. For example, XeF (xenon fluoride) excimer laser (irradiation light wavelength is 351 nm), XeCl (xenon chloride) excimer laser ( It is also possible to use a laser light source having a wavelength of irradiation light of 308 nm.

  As the reaction proceeds, the concentration of hydrogen gas and chlorine gas in the photoreactor 2 decreases, but the energy of the light emitted from the light source is the number of photons, and the mole of chlorine gas in the photoreactor 2. Chlorine radicals can be generated sufficiently if the number is about 1 / 10,000 to 1 / 10,000 or more.

  The light source may be disposed in the photoreactor 2 or may be disposed outside the photoreactor 2. When arranged outside the photoreactor 2, a window member that is transparent to light in the above wavelength band is provided on the wall of the photoreactor 2, and light is taken into the photoreactor 2 from this window member. A configuration is adopted in which light is guided into the photoreactor 2 using a light conduit such as an optical fiber. If a light source is arranged in the photoreactor 2, it is preferable not to use such a configuration for light irradiation. Further, if the light source is arranged in the photoreactor 2, there is no need to use a window member or the like, so that the photoreactor 2 can be configured using a material having excellent pressure resistance.

  Since the reaction rate of hydrogen chloride in the present invention is relatively high, the volume of the photoreactor 2 can be reduced. The residence time of the supplied raw material gas in the photoreactor 2 is preferably set to a volume of several seconds to several tens of seconds. When the residence time is shorter than this range, a part of hydrogen or chlorine may flow out of the photoreactor 2 without being reacted. When the residence time is longer than this range, the photoreactor Since the production reaction is substantially completed within 2, there is no need to increase the residence time.

  As a material constituting the photoreactor 2, a general metal material can be used as having resistance to temperatures up to about 500 ° C., and cast iron, SUS304, SUS310, SUS316, SUS316L, nickel, titanium. , Tantalum, high heat-resistant and corrosion-resistant special alloy, and the like can be suitably used. Further, glass materials such as glass, heat-resistant glass, and quartz glass can be suitably used, and materials obtained by coating these materials on the metal surface, such as glass lining materials, can also be used. Furthermore, as a material having resistance to temperatures up to about 250 ° C., a material coated with a polyfluorinated hydrocarbon such as a fluorinated ethylene resin, polyvinylidene fluoride, or polytetrafluoroethylene can be used.

  The cooler 3 only needs to be capable of lowering the temperature of the mixture containing the hydrogen chloride gas of the reaction product derived from the photoreactor 2, and the mixture is preferably 200 ° C. or less, more preferably 100 ° C. It is desirable to be able to cool to below. When the temperature of the mixture is higher than 200 ° C., a thermal load is applied to the pump 5 for reusing hydrogen chloride as a raw material, which is not preferable. Further, in order to reduce the load applied to the cooler 3, if the temperature of the mixture is lowered in advance, it is necessary to increase the ratio of hydrogen chloride gas in the raw material and reduce the content of hydrogen gas and chlorine gas, Since the production amount per unit time per unit volume of the photoreactor 2 is decreased, it is not preferable.

  As the cooler 3, a multi-tube heat exchanger, a double-tube heat exchanger, a glass lining heat exchanger, a multi-tube glass lining heat exchanger, a coil heat exchanger, a spiral heat exchanger, A plate heat exchanger, a trombone heat exchanger, an impervious graphite heat exchanger, or the like can be used.

  As a material constituting the cooler 3, cast iron, SUS304, SUS310, SUS316, SUS316L, nickel, titanium, tantalum, a high heat resistant corrosion resistant special alloy, or the like can be suitably used. Further, glass materials such as glass, heat-resistant glass, and quartz glass can be suitably used, and materials obtained by coating these materials on the metal surface, such as a glass lining material chamber, can also be used. Also, fluororesin impregnated impermeable graphite can be used.

  As the compressor 4, a reciprocating compressor (reciprocating compressor), a screw compressor, a diaphragm compressor, a centrifugal compressor, or the like can be used. A blower can be used in place of the compressor. As the blower, a reciprocating pump, a rotary pump, a turbo blower, a volume blower, a centrifugal fan, a mixed flow fan, an axial flow fan, or the like can be used.

[Example]
Example 1
A cylindrical glass flask made of heat-resistant glass having a diameter of 20 cm and a height of 50 cm, in which two raw material gas inlets were provided in the upper part and one reaction product outlet was provided in the lower part, was used as the photoreactor 2. The source gas was blown so that the source gas introduced from the inlet of the source gas swirled in the circumferential direction above the photoreactor 2. The raw material gas was continuously supplied from the cylinder at the following supply amounts. Source hydrogen gas is supplied from one inlet at a flow rate of 6 NL / min. From the other inlet, a mixed gas of chlorine gas and hydrogen chloride gas is supplied, and chlorine gas is 5 NL / min and hydrogen chloride gas is 120 NL / min. The flow rate was The unit “NL / min” is a flow rate unit represented by a volume (liter) in which a standard state gas flows per minute.

  In the center of the photoreactor 2, a 100 W high-pressure mercury lamp (Mushio manufactured by Ushio Inc.) was placed as a light source and irradiated with light. The temperature of the raw material gas was 30 ° C., and the temperature of the mixture containing hydrogen chloride gas led out from the photoreactor 2 after the reaction was 198 ° C. The composition of the mixture derived from the photoreactor 2 was 0.8 vol% hydrogen and 99.2 vol% hydrogen chloride, and no chlorine was observed.

(Example 2)
Instead of disposing a high-pressure mercury lamp as a light source in the photoreactor 2, it was the same as in Example 1 except that it was disposed outside the photoreactor 2 and irradiated with light from the outside. A 100 W high pressure mercury lamp (USHIO Inc., M-102) was placed at a distance of 1 m from the center of the photoreactor 2. The temperature of the raw material gas was 30 ° C., and the temperature of the mixture containing hydrogen chloride gas led out from the photoreactor 2 after the reaction was 190 ° C. The composition of the mixture derived from the photoreactor 2 was 0.7 vol% hydrogen, 99.3 vol% hydrogen chloride, and 50 ppm chlorine.

(Example 3)
Example 2 was the same as Example 2 except that the flow rate of hydrogen gas to be introduced was 16.5 NL / min, the flow rate of chlorine gas was 15 NL / min, and the flow rate of hydrogen chloride gas was 120 NL / min. The temperature of the raw material gas was 30 ° C., and the temperature of the mixture containing hydrogen chloride gas led out from the photoreactor 2 after the reaction was 480 ° C. The composition of the mixture derived from the photoreactor 2 was 1.0 vol% hydrogen and 99.0 vol% hydrogen chloride, and no chlorine was observed.

Example 4
The mixture containing hydrogen chloride gas derived from the photoreactor 2 of Example 1 was cooled using ice water as a refrigerant and a condenser made of SUS316L having a heat transfer area of 0.3 m ² as the cooler 3. The temperature of the mixture was cooled to 30 ° C. by the cooler 3. This mixture was combined with chlorine gas by a pump 5 at 120 NL / min and reused as a raw material gas. The temperature of the raw material gas was 30 ° C., and the temperature of the mixture containing hydrogen chloride gas led out from the photoreactor 2 after the reaction was 190 ° C. The composition of the mixture derived from the photoreactor 2 was 0.6 vol% hydrogen and 99.4 vol% hydrogen chloride, and no chlorine was observed.

(Example 5)
By compressing the mixture derived from the cooler 3 of Example 4 to 0.9 MPaG using the compressor 4 and cooling the jacketed container (volume 2 L) with dry ice-acetone cryogen (−78 ° C.). Hydrogen chloride was liquefied. At this time, the reaction was continued for 1 hour while purging the gas phase from the abatement line. The obtained liquefied hydrogen chloride was 958 kg, and the yield was 98%. Hydrogen as an impurity contained in liquefied hydrogen chloride was 1 ppm or less.

(Example 6)
Example 1 was performed except that the flow rate of hydrogen gas to be introduced was 4 NL / min, the flow rate of chlorine gas was 5 NL / min, and the flow rate of hydrogen chloride gas was 120 NL / min. The temperature of the raw material gas was 30 ° C., and the temperature of the mixture containing hydrogen chloride gas led out from the photoreactor 2 after the reaction was 160 ° C. The composition of the mixture derived from the photoreactor 2 was 0.8 vol% hydrogen and 99.2 vol% hydrogen chloride, and no chlorine was observed.

(Example 7)
Other than introducing the hydrogen gas flow rate to 6 NL / min, the chlorine gas flow rate to 5 NL / min, the hydrogen chloride gas flow rate to 120 NL / min, and introducing them into the photoreactor 2 as a premixed mixed gas Was the same as in Example 1. The temperature of the raw material gas was 30 ° C., and the temperature of the mixture containing hydrogen chloride gas led out from the photoreactor 2 after the reaction was 198 ° C. The composition of the mixture derived from the photoreactor 2 was 0.8 vol% hydrogen and 99.2 vol% hydrogen chloride, and no chlorine was observed.

DESCRIPTION OF SYMBOLS 1 Hydrogen chloride production apparatus 2 Photoreactor 3 Cooler 4 Compressor 5 Pump

Claims (6)

  A method for producing hydrogen chloride, which comprises irradiating hydrogen gas and chlorine gas with light in the presence of hydrogen chloride gas and reacting the hydrogen gas and chlorine gas to produce hydrogen chloride gas. A mixing step of mixing hydrogen gas, chlorine gas, and hydrogen chloride gas to obtain a mixed gas;
And a light irradiation step of generating hydrogen chloride gas by irradiating the mixed gas with light and reacting hydrogen gas and chlorine gas contained in the mixed gas. A supply step of continuously supplying hydrogen gas, chlorine gas and hydrogen chloride gas to the reactor,
And a light irradiation step of generating hydrogen chloride gas by irradiating the hydrogen gas and chlorine gas supplied to the reactor with light in the presence of hydrogen chloride gas and reacting the hydrogen gas and chlorine gas with each other. A method for producing hydrogen chloride.   The number of moles of hydrogen chloride gas at the start of light irradiation is at least 5 times the number of moles of the smaller number of moles of hydrogen gas and moles of chlorine gas. The manufacturing method of hydrogen chloride as described in any one.   The method for producing hydrogen chloride according to any one of claims 1 to 4, wherein the number of moles of hydrogen gas at the start of light irradiation is greater than the number of moles of chlorine gas.   The method for producing hydrogen chloride according to any one of claims 1 to 5, wherein the wavelength of light irradiated to the hydrogen gas and the chlorine gas is 250 to 450 nm.

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