CN109485019B - Gas phase circulating device and method for producing thionyl chloride - Google Patents
Gas phase circulating device and method for producing thionyl chloride Download PDFInfo
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- CN109485019B CN109485019B CN201811427355.3A CN201811427355A CN109485019B CN 109485019 B CN109485019 B CN 109485019B CN 201811427355 A CN201811427355 A CN 201811427355A CN 109485019 B CN109485019 B CN 109485019B
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Abstract
The invention provides a gas phase circulation device and a gas phase circulation method for thionyl chloride production, wherein the gas phase circulation is that non-condensable gas removed from at least one of a condenser, a degassing and purifying kettle and rectifying equipment is conveyed into a gas separator, chlorine gas after separation is introduced into a sulfur dichloride synthesis kettle, and sulfur dioxide after separation is introduced into a thionyl chloride crude product synthesis kettle. The invention adopts the gas one-way conveying device to convey the non-condensable tail gas generated in the condenser, the crude product receiving tank and the rectifying equipment to the gas separator, the gas separator is internally provided with the adsorption device and the desorption device, the adsorption device is used for absorbing sulfur dioxide in the non-condensable gas, when the non-condensable gas passes through the gas separator, the unabsorbed chlorine gas is directly introduced into the sulfur dichloride synthesis kettle, and the sulfur dichloride is completely absorbed by the adsorption device, so that the chlorine gas and the sulfur dioxide are effectively separated, and the pressure rise in the thionyl chloride synthesis kettle is avoided, and the normal operation of the reaction is influenced.
Description
Technical Field
The invention relates to the field of chemical processes, in particular to a gas phase circulating device and method for producing thionyl chloride.
Background
There are more than ten methods for producing thionyl chloride, but the mass industrial production is basically the following three process routes: (1) the phosphorus pentachloride reacts with the sulfur dioxide, the process is simple, but the SOCl2With POCl3Difficult separation and difficult obtaining of high-purity SOCl2(ii) a (2) Antimony chloride and the like are used as catalysts, sulfur chloride reacts with chlorosulfonic acid, and the antimony chloride and the like are widely adopted at present at home, the process is complex, and the investment is large; (3) the gas phase catalysis method for producing the thionyl chloride takes the active carbon as the catalyst, the thionyl chloride reacts with the sulfur dioxide and the chlorine gas, the method is widely adopted abroad, the process is simple, the investment is low, the product purity is high, the method can adopt a closed internal circulation device for production, the method has no environmental pollution, and the basic reaction formula is as follows:
(1)、
(2)、
as a representative of the above prior art (3), US2431823 discloses the use of disulfide dichloride (S)2Cl2) With chlorineGas reaction to produce sulfur dichloride (SCl)2) And excessive chlorine gas, sulfur dioxide and introduced chlorine gas react under the catalysis of activated carbon, and thionyl chloride is obtained through distillation; the document also discloses that a sulfur monochloride mixture, mainly comprising sulfur, after having been fluidized bed and distilled after the reaction, is chlorinated by a chlorinator and then fed to a preheater a, where a new reaction is started. However, in the disclosed document, the gas from the condenser and the degasser is combined and then transferred to the thionyl chloride synthesis reactor by a fan, which brings about many problems, for example, the arrangement of the document may cause the gas from the condenser and the degasser not to enter the synthesis vessel or cause the degasser or the condenser to fluctuate in pressure under the pressure fluctuation of the synthesis reactor, and although it is proposed in another patent application of the present investigator to provide a return pipe before and after the fan, it may still cause difficulty in continuous production. In addition, the prior art CN103043620A also discloses an operation of a thionyl chloride gas phase closed cycle, but the adopted gas compression conveying machinery is a liquid ring compressor, and although the liquid ring compressor is convenient for automatic control, in order to perform liquid sealing and temperature reduction during use, one or two existing materials in the thionyl chloride production process are required to be used as working media, thereby causing waste of part of the materials in the production process. However, in the operation of gaseous phase closed cycle of thionyl chloride of CN101412502B in the prior art, a gas unidirectional transportation device is adopted to transport the gas dissolved in the crude thionyl chloride to the thionyl chloride synthesis kettle by adjusting the temperature of the degassing purification kettle for crude product so as to increase the pressure thereof, and since thionyl chloride has a low boiling point and is easily decomposed, the degassing method that the gas is extracted and returned to the thionyl chloride synthesis kettle by increasing the temperature of the material will cause loss of part of the thionyl chloride product. In addition, the gas phase circulation method for producing thionyl chloride in the prior art is tail alignmentThe gas is not separated and directly circulated to the thionyl chloride synthesis kettle, but the tail gas contains various gases such as sulfur dichloride, sulfur dioxide and chlorine, while the chlorine is not only used for synthesizing thionyl chloride but also used for synthesizing the sulfur dichloride, so that the tail gas is directly introduced into the thionyl chloride synthesis kettle without separation operation, which may cause the shortage of raw materials of the thionyl chloride in the circulating production process, and the influence of the thionyl chloride on the whole continuous production process is carried out, which influences the product yield. In the prior art CN106145059A, the tail gas is separated and recovered, but SO is separated and recovered2In a complicated manner, requiring the introduction of SO2Condensed and collected before gasification due to SO2The boiling point is low, the requirement on condensation conditions is extremely high, more resources are consumed, the cost is high, resources are wasted, and the yield of the thionyl chloride product is low.
In view of the above, the present invention is particularly proposed.
Disclosure of Invention
In order to solve the problems, the invention provides a gas phase circulation method for thionyl chloride production, and aims to effectively separate chlorine gas from sulfur dioxide in non-condensable tail gas and avoid the problem that the pressure in a thionyl chloride synthesis kettle is increased to influence the normal operation of reaction.
In order to achieve the purpose, the invention adopts the following technical scheme:
a gas phase circulation method for producing thionyl chloride is characterized in that non-condensable gas removed from at least one of a condenser, a degassing and purifying kettle and a rectifying device is conveyed into a gas separator, separated chlorine gas is introduced into a sulfur dichloride synthesis kettle, and separated sulfur dioxide is introduced into a thionyl chloride crude product synthesis kettle.
Preferably, an adsorption device and a desorption device are arranged in the gas separator, an adsorbent is arranged in the adsorption device, the adsorbent is used for absorbing sulfur dioxide in the non-condensable gas, and the desorption device desorbs the adsorbent after adsorbing the sulfur dioxide.
Preferably, the adsorbent in the adsorption device is a solid or liquid phase adsorbent, and the liquid phase adsorbent is at least one of saturated salt water or organic alcohol amine solution.
Preferably, the liquid phase adsorbent adsorbing the sulfur dioxide is introduced into an ultrasonic treatment device for degassing treatment, and the sulfur dioxide is removed again
Preferably, the thionyl chloride production process comprises:
(1) and (3) synthesis of sulfur dichloride: reacting liquid sulfur monochloride and chlorine gas in a sulfur dichloride synthesis kettle, wherein the pressure P1 at the air outlet of the sulfur dichloride synthesis kettle is 0.01-0.02 MPa;
(2) synthesis of crude thionyl chloride: introducing mixed gas discharged from a sulfur dichloride synthesis kettle into a thionyl chloride synthesis kettle, and introducing metered sulfur dioxide gas into a thionyl chloride crude product synthesis kettle, wherein the pressure P2 of a gas outlet of the thionyl chloride crude product synthesis kettle is 0.01-0.02 MPa;
(3) condensation of crude thionyl chloride: introducing mixed gas generated by a thionyl chloride synthesis kettle into a thionyl chloride crude product condenser to obtain a condensation product, wherein non-condensable gas is sent to a gas separator;
(4) receiving a thionyl chloride crude product: introducing a condensation product generated in a thionyl chloride crude product condenser into a crude product receiving tank, degassing and purifying to obtain crude thionyl chloride, and extracting low-boiling-point substances into a gas separator by using a gas one-way conveying device;
(5) and (3) sulfur preparation reaction: introducing a purified product generated by a crude product receiving tank degassing purification kettle into a sulfur preparation kettle, and performing sulfur preparation reaction under a normal pressure state, wherein the addition amount of sulfur is 70-80% of the sulfur amount required by complete reaction;
(6) rectification and purification: and introducing the product of the sulfur-preparing reaction into a rectifying device for rectification and purification, and simultaneously carrying out excessive vulcanization in the rectifying device to finally obtain a finished product of thionyl chloride.
Preferably, the pressure P1 at the gas outlet of the sulfur dichloride synthesis kettle is greater than the pressure P2 at the gas outlet of the thionyl chloride crude product synthesis kettle, the height of the sulfur dichloride synthesis kettle is higher than that of the thionyl chloride synthesis kettle, and the position of the thionyl chloride crude product receiving tank is higher than that of the crude product sulfur preparation kettle.
The position of the gas separator is higher than the position of the thionyl chloride synthesis kettle and the position of the sulfur dichloride synthesis kettle.
Preferably, the method for adding sulfur into the sulfur preparation kettle comprises the steps of firstly selecting sulfur blocks for later use, then crushing the selected sulfur blocks and desiccant calcium chloride particles together, enabling the crushed particles to reach 30-50 meshes, and then sending the crushed mixed powder into the sulfur preparation kettle for sulfur preparation reaction.
Preferably, the gas one-way conveying device is provided with at least one liquid injection device, and the liquid injection device introduces the extracted non-condensable gas into the gas separator.
The invention also provides a gas phase circulating device for producing thionyl chloride, which comprises a thionyl chloride synthesis kettle, a sulfur preparation kettle, a crude product condenser, a crude product receiving tank, a liquid injection device and a gas separator, wherein an adsorption device and a desorption device are arranged in the gas separator.
The method can effectively prevent the fluctuation between the condenser and the thionyl chloride synthesis reactor.
1. By adopting the process, the consumption of raw materials is reduced, the yield is high relative to the feeding of the raw materials, and the utilization rate of the raw materials is up to more than 99.0 percent; under the process conditions described in the present invention, with appropriate control, the conversion of sulphur and chlorine (the most important reactants from an economic point of view) to thionyl chloride approaches 100%.
2. Separating SO from gas by full-circulation and full-closed process2And Cl2The mixed gas and liquid phase products except the thionyl chloride generated at each station can be recycled to the corresponding feeding position, so that the whole device is basically free from the outward discharge of three-waste liquid gas.
3. In the integral production process of the thionyl chloride, the invention adopts a gas one-way conveying device to convey non-condensable tail gas generated in a condenser, a crude product receiving tank and rectifying equipment to a gas separator, an adsorption device and a desorption device are arranged in the gas separator, and the adsorption device is used for absorbing sulfur dioxide in the non-condensable gas but not absorbing chlorine in the non-condensable gas. After the non-condensable gas passes through the gas separator, the chlorine gas which is not absorbed is directly introduced into the sulfur dichloride synthesis kettle, and the sulfur dichloride is completely absorbed by the adsorption device, so that the chlorine gas and the sulfur dioxide are effectively distinguished, and the pressure rise in the thionyl chloride synthesis kettle is avoided to influence the normal operation of the reaction.
4. By adopting the process, the maintenance cost is reduced, and can be ignored compared with the original gas phase circulating device and the process; under the process conditions of the invention, the production operation is more stable, the productivity is improved by more than 5 percent compared with the original gas phase circulation process, and the production scale can be easily enlarged.
Drawings
FIG. 1 is a basic flow diagram of the gas phase recycling method for thionyl chloride production according to the present invention;
FIG. 2 is a schematic illustration of a gas separation apparatus according to the present invention;
FIG. 3 is a schematic diagram of a thermostatic control system for a rectification apparatus in accordance with the present invention.
The method comprises the following steps of 1-a sulfur dichloride synthesis kettle, 2-a thionyl chloride synthesis kettle, 3-a sulfur preparation kettle, 4-a crude product condenser, 5-a gas-liquid separator, 6-a crude product receiving tank, 7-a liquid injection device, 8-a circulating pump, 9-a rectifying kettle, 10-a rectifying tower, 11-a finished product condenser, 12-a gas separator, 13-an adsorption device, 14-a desorption device, 15-an input pipeline, 16-a connecting pipeline, 17-a chlorine gas output pipeline, 18-a sulfur dioxide output pipeline, 19-a constant temperature control box, 20-a heating device, 21-a low-temperature liquid storage tank, 22-a first valve, 23-a second valve, 24-a liquid outlet, 25-a first temperature detector and 26-a second temperature detector.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive effort based on the embodiments of the present invention, are within the scope of the present invention.
The invention aims to provide a method for pumping gas and realizing gas-liquid separation in a receiving tank for crude thionyl chloride products by arranging a liquid injection device at a gas discharge port of a thionyl chloride condenser by utilizing fluid dynamics so as to send the gas into a thionyl chloride synthesis reactor for recycling. So as to form a totally-enclosed circulating production process of the thionyl chloride.
The object of the invention can be achieved by: the synthesis of thionyl chloride is described below, namely:
1. synthesis of Sulfur monochloride (S)2Cl2)；
2. Synthesis of Sulfur dichloride (SCl)2)；
3. Synthesis of thionyl chloride (SOCl)2)；
4. Rectifying thionyl chloride;
in the process of producing the thionyl chloride, a plurality of devices can generate recyclable gas, and firstly, part of low-boiling-point gas can be recycled after the crude product of the thionyl chloride is cooled by a condensing device; secondly, the receiving tank for the crude product of the thionyl chloride can generate part of non-condensable gas after degassing and purification; thirdly, the devices like the rectifying tower and the like have part of gas which can be recycled.
If the mixed gas is discharged, waste and pollution are likely to be caused, and more importantly, the invention relates to a totally-closed full-cycle production process of thionyl chloride, in order to ensure that no redundant waste material is exhausted in the production process, namely the waste material does not enter the production cycle any more, the recycling amount of liquid or gas needs to be increased consciously, so that the recycling of the gas and how to keep the pressure of a thionyl chloride synthesis reactor and a crude product condenser from interfering with each other in the recycling become an important problem.
The solution provided by the invention is that a gas one-way conveying device, specifically a liquid injection device, is arranged at a gas discharge port of at least one of a crude product condenser, a crude product receiving tank and a rectifying tower, and the gas is extracted and treated and then sent to a synthesis reactor for reuse, so that the totally-closed cycle production process of the thionyl chloride is formed.
In the invention, the gas phase circulation is that the non-condensable gas removed from at least one of the condenser, the crude product receiving tank and the rectifying equipment is conveyed into a gas separator, the separated chlorine gas is introduced into a sulfur dichloride synthesis kettle, and the separated sulfur dichloride is introduced into a thionyl chloride crude product synthesis kettle.
The gas separator is internally provided with an adsorption device and a desorption device, wherein an adsorbent is arranged in the adsorption device, the adsorbent is used for absorbing sulfur dioxide in non-condensable gas, and the desorption device desorbs the adsorbent after the sulfur dioxide is adsorbed.
The adsorbent in the adsorption device is a solid or liquid phase adsorbent, the solid adsorbent can be magnesium oxide, and the liquid phase adsorbent is at least one of saturated salt water or organic alcohol amine solution.
The solid phase adsorbent after the adsorption is washed by water or heated to regenerate and separate out sulfur dioxide, and the liquid phase adsorbent after the adsorption of the sulfur dioxide is introduced into an ultrasonic treatment device to be degassed, so that the sulfur dioxide is removed again.
The specific thionyl chloride production process of the invention comprises the following steps:
(1) and (3) synthesis of sulfur dichloride: reacting liquid sulfur monochloride and chlorine gas in a sulfur dichloride synthesis kettle, wherein the pressure P1 at the air outlet of the sulfur dichloride synthesis kettle is 0.01-0.02 MPa;
(2) synthesis of crude thionyl chloride: introducing mixed gas discharged from a sulfur dichloride synthesis kettle into a thionyl chloride synthesis kettle, and introducing metered sulfur dioxide gas into a thionyl chloride crude product synthesis kettle, wherein the pressure P2 of a gas outlet of the thionyl chloride crude product synthesis kettle is 0.01-0.02 MPa;
(3) condensation of crude thionyl chloride: introducing mixed gas generated by a thionyl chloride synthesis kettle into a thionyl chloride crude product condenser to obtain a condensation product, wherein non-condensable gas is sent to a gas separator;
(4) receiving a thionyl chloride crude product: introducing a condensation product generated in a thionyl chloride crude product condenser into a crude product receiving tank, degassing and purifying to obtain crude thionyl chloride, and extracting low-boiling-point substances into a gas separator by using a gas one-way conveying device;
(5) and (3) sulfur preparation reaction: introducing a purified product generated by a crude product receiving tank degassing purification kettle into a sulfur preparation kettle, and performing sulfur preparation reaction under a normal pressure state, wherein the addition amount of sulfur is 70-80% of the sulfur amount required by complete reaction;
(6) rectification and purification: and introducing the product of the sulfur-preparing reaction into a rectifying device for rectification and purification, and simultaneously carrying out excessive vulcanization in the rectifying device to finally obtain a finished product of thionyl chloride.
The gas outlet pressure P1 of the sulfur dichloride synthesis kettle is greater than the gas outlet pressure P2 of the thionyl chloride crude synthesis kettle, the height of the sulfur dichloride synthesis kettle is higher than that of the thionyl chloride synthesis kettle, the position of the thionyl chloride crude receiving groove is higher than that of the crude sulfur preparation kettle, and the position of the gas separator is higher than that of the thionyl chloride synthesis kettle and that of the sulfur dichloride synthesis kettle.
In the invention, the thionyl chloride crude product is condensed and then reaches the gas-liquid separator, the gas one-way conveying device extracts the non-condensable gas in the gas-liquid separator, and after the extracted non-condensable gas is introduced into the thionyl chloride crude product receiving tank again, the gas one-way conveying device extracts the non-condensable gas in the crude product receiving tank again and conveys the non-condensable gas to the gas separator.
The gas one-way conveying device is a liquid injection device, at least one liquid injection device is arranged, and the extracted non-condensable gas is introduced into the gas separator by the liquid injection device.
Example 1
This example describes a method of the present invention in which gas removed from a crude condenser is recycled in a thionyl chloride synthesis reactor as a part of a raw material source of a thionyl chloride synthesis gas, thereby completing a gas phase cycle, the method comprising:
(1) and (2) carrying out sulfur preparation on crude thionyl chloride with the thionyl chloride content accounting for 68% of the total amount of the crude thionyl chloride in a sulfur preparation kettle, wherein the crude thionyl chloride also contains 15% of sulfur dichloride, the temperature in the sulfur preparation kettle is 78 ℃ of the residual temperature of the crude thionyl chloride, the pressure in the sulfur preparation kettle is normal pressure, sulfur which is not excessive relative to the sulfur dichloride in the crude thionyl chloride is added into the crude thionyl chloride, and the adding amount of the sulfur is 80% of the amount of the sulfur required for complete reaction with the sulfur dichloride in the crude thionyl chloride, so that other substances except the thionyl chloride in the crude thionyl chloride are converted into sulfur monochloride, and the sulfurized crude thionyl chloride is obtained.
(2) Rectifying the sulfur-mixed crude product of thionyl chloride to obtain thionyl chloride and a mixed high-boiling-point substance, wherein the rectification is carried out in a rectifying tower to carry out three-stage rectification;
a. primary rectification: the temperature of the tower bottom is controlled between 110 ℃ and 130 ℃, 80 percent of thionyl chloride is obtained at the tower top, in the first-stage rectification, intermittent feeding is adopted, so that a small amount of sulfur dichloride volatilized along with the thionyl chloride gas is in contact reaction with excessive sulfur in a fluidized bed at the top of the rectification tower and is converted into sulfur monochloride, and then the sulfur monochloride flows back to the tower bottom;
b. secondary rectification: the temperature of the tower kettle is controlled between 70 ℃ and 105 ℃, when the temperature of the tower kettle reaches a certain liquid level and reaches 89 ℃, the high mixture of the tower kettle is discharged to a first-stage rectifying tower, and about 98 percent SOCl is obtained from the top of the tower2；
c. Three-stage rectification: the process is carried out under the conditions that the temperature of a tower kettle is 78-80 ℃, the temperature of a tower top is 72-75 ℃, the reflux ratio is 1:1 and the pressure is 0.02-0.03MPa, and SOCl with the purity of 99.8 percent is obtained from the tower top2。
(3) Reacting the mixed high-boiling-point substance with excessive chlorine to obtain sulfur dichloride mixed gas;
discharging the mixed high-boiling-point substances in the rectifying tower from the tower to directly reach the kettle, then sending the mixed high-boiling-point substances to a sulfur dichloride synthesis kettle through a pump, introducing chlorine, reacting sulfur monochloride in the mixed high-boiling-point substances with excessive chlorine under the conditions of 70 ℃ and 0.02MPa, and introducing Cl2With liquid S in a sulphur dichloride synthesis kettle2Cl2The volume ratio of (A) to (B) is 150: 0.2; cl2And S2Cl2SCl generated by reaction in a sulfur dichloride synthesis kettle2And an excess of Cl2Is discharged from a gas outlet, and the pressure P1 of the gas outlet is 0.02 MPa.
(4) Sulfur dichloride with excess Cl2The mixed gas is sent to a thionyl chloride synthesis reactor, sulfur dioxide gas is introduced into the synthesis reactor, and gas Cl in the synthesis reactor2：SO2：S2Cl2The volume ratio of (liquid) is 150:100:0.2, the mixture is sent to a thionyl chloride synthesis kettle to synthesize thionyl chloride, the temperature in a thionyl chloride synthesis reactor is 250 ℃, the pressure is 0.10MPa, and the thionyl chloride mixed gas is obtained after the synthesis is finished.
(5) Condensing the obtained mixed gas of thionyl chloride in a crude product condenser, wherein the specific conditions of condensation are about 35 ℃, the content of thionyl chloride in the obtained condensation product is 68%, the content of sulfur dichloride is 25%, chlorine is 4%, and sulfur dioxide is 3%, wherein the non-condensable gas is extracted by a gas one-way conveying device such as a liquid injection device and is sent into a thionyl chloride synthesis reactor, so that gas phase circulation is completed.
In order to maintain the circulation of the gas in the whole production process, the gas from the crude product condenser forms unidirectional conveying gas due to the gas unidirectional conveying device, so that the gas phase circulation of the thionyl chloride production can be better promoted.
In order to reduce the energy consumption and possible leakage caused by pumping, the invention also arranges the position of the crude product condenser at a position higher than the crude product receiving groove, arranges the position of the crude product receiving groove of the thionyl chloride at a position higher than the sulfur preparation kettle, and preferably arranges the position of a liquid phase discharge outlet of the crude product condenser at a position higher than a liquid phase feed inlet of the crude product receiving groove so as to form a pressure difference to ensure that the liquid can be transported without obstruction.
Example 2
This example describes the gas phase recycle method of the present invention, in which the gas discharged from the rectifying tower is used as a part of the raw material source of the synthesis gas of thionyl chloride, and the gas is recycled in the thionyl chloride synthesis reactor. The method comprises the following specific steps:
the crude thionyl chloride after sulfidation was distilled in a distillation column as described in step (2) of example 1 to obtain thionyl chloride and a mixed high boiling substance and off-gas containing sulfur dioxide (about 45%), thionyl chloride (about 48%), sulfur dichloride (about 5%), chlorine (about 2%). Discharging the mixed high-boiling-point substance from the tower to directly reach the kettle, and then sending the mixed high-boiling-point substance to a sulfur dichloride synthesis kettle through a pump to complete liquid phase circulation. And the tail gas mainly comprises sulfur dioxide and chlorine gas which are sent into the thionyl chloride synthesis reactor through a gas one-way conveying device such as a liquid injection device, thereby completing gas phase circulation.
Example 3
This example describes a method for completing gas phase circulation by recycling non-condensable gas removed from a receiving tank for crude thionyl chloride in the present invention as a part of a raw material source of a synthesis gas of thionyl chloride in a thionyl chloride synthesis reactor. The method comprises the following specific steps:
and (2) condensing the thionyl chloride mixed gas in a crude product condenser, wherein the specific conditions of condensation are about 35 ℃, the content of thionyl chloride in the obtained condensation product is 68%, the content of sulfur dichloride is 25%, chlorine is 4% and sulfur dioxide is 3%, introducing the condensation product into a crude product receiving tank of thionyl chloride for degassing and purification, and conveying the non-condensable gas generated by degassing and purification into a thionyl chloride synthesis reactor through a gas one-way conveying device such as a liquid spraying device, thereby completing gas phase circulation.
Example 4
This example describes a process for the separation of the gas evolved in the crude condenser of example 1 into sulfur dioxide and chlorine gas, the sulfur dioxide separated being fed to a thionyl chloride synthesis reactor and the chlorine gas separated being fed to a sulphur dichloride synthesis kettle to complete the gas phase cycle, the process comprising:
wherein the steps (1) to (4) are the same as in example 1;
(5) condensing the obtained thionyl chloride mixed gas in a crude product condenser, wherein the specific conditions of condensation are about 35 ℃, the content of thionyl chloride in the obtained condensation product is 68%, the content of sulfur dichloride is 25%, chlorine is 4%, and sulfur dioxide is 3%, wherein the non-condensable gas is extracted by a gas one-way conveying device such as a liquid injection device and is sent into a gas separator, an adsorption device and a desorption device are arranged in the gas separator, the non-condensable gas conveyed by the gas one-way conveying device enters the adsorption device, an adsorbent in the adsorption device absorbs the sulfur dioxide in the non-condensable gas but not the chlorine, so that the sulfur dioxide and the chlorine are separated, the chlorine passes through the adsorption device and is directly sent into a sulfur dichloride synthesis kettle, the adsorbent which adsorbs the sulfur dioxide periodically enters a desorption device, and the desorption device removes the adsorbed sulfur dioxide by an ultrasonic method, then the desorbed sulfur dioxide enters a thionyl chloride synthesis kettle, thereby completing gas phase circulation.
The adsorbent described in this embodiment is a liquid phase adsorbent, specifically at least one of a saturated salt solution or an organic alcohol amine solution.
Example 5
The embodiment describes a method for completing gas phase circulation by introducing gas discharged from a rectifying tower into a gas separator, separating the gas into sulfur dioxide and chlorine gas, introducing the separated sulfur dioxide into a thionyl chloride synthesis reactor, and introducing the separated chlorine gas into a sulfur dichloride synthesis kettle, which comprises the following specific steps:
the crude thionyl chloride after sulfidation was distilled in a distillation column as described in step (2) of example 1 to obtain thionyl chloride and a mixed high boiling substance and off-gas containing sulfur dioxide (about 45%), thionyl chloride (about 48%), sulfur dichloride (about 5%), chlorine (about 2%). Discharging the mixed high-boiling-point substance from the tower to directly reach the kettle, and then sending the mixed high-boiling-point substance to a sulfur dichloride synthesis kettle through a pump to complete liquid phase circulation. The tail gas mainly comprises sulfur dioxide and chlorine gas which are sent into a gas separator through a gas one-way conveying device such as a liquid spraying device, an adsorption device and a desorption device are arranged in the gas separator, the non-condensable gas conveyed through the gas one-way conveying device enters the adsorption device, an adsorbent in the adsorption device absorbs the sulfur dioxide in the non-condensable gas but does not absorb the chlorine gas, so that the sulfur dioxide and the chlorine gas are separated, the chlorine gas directly enters a sulfur dichloride synthesis kettle after passing through the adsorption device, the adsorbent which adsorbs the sulfur dioxide periodically enters the desorption device, the desorption device desorbs the adsorbed sulfur dioxide through an ultrasonic method, and then the desorbed sulfur dioxide enters a thionyl chloride synthesis kettle, so that gas phase circulation is completed.
The adsorbent described in this embodiment is a liquid phase adsorbent, specifically at least one of a saturated salt solution or an organic alcohol amine solution.
Example 6
The embodiment describes a method for completing gas phase circulation by introducing non-condensable gas removed from a crude thionyl chloride receiving tank into a gas separator, separating the non-condensable gas into sulfur dioxide and chlorine gas, introducing the separated sulfur dioxide into a thionyl chloride synthesis reactor, and introducing the separated chlorine gas into a sulfur dichloride synthesis kettle, which comprises the following specific steps:
condensing the thionyl chloride mixed gas in a crude product condenser, wherein the specific conditions of the condensation are about 35 ℃, the content of thionyl chloride in the obtained condensation product is 68%, the content of sulfur dichloride is 25%, chlorine is 4% and sulfur dioxide is 3%, introducing the condensation product into a thionyl chloride crude product receiving tank for degassing and purification, delivering non-condensable gas generated by degassing and purification into an adsorption device through a gas one-way conveying device such as a liquid spraying device, absorbing sulfur dioxide in the non-condensable gas by an adsorbent in the adsorption device without absorbing chlorine, thereby separating sulfur dioxide from chlorine, directly introducing chlorine into a sulfur dichloride synthesis kettle after passing through the adsorption device, periodically introducing the adsorbent which absorbs sulfur dioxide into a desorption device, desorbing the adsorbed sulfur dioxide by the desorption device through an ultrasonic method, and then introducing the desorbed sulfur dioxide into the thionyl chloride synthesis kettle, thereby completing the gas phase cycle.
The adsorbent described in this embodiment is a liquid phase adsorbent, specifically at least one of a saturated salt solution or an organic alcohol amine solution.
Example 7
This example describes a method for completing gas phase circulation by using non-condensable gases generated by a crude product condenser, a rectifying tower and a crude product receiving tank in the present invention as a part of a gas raw material source, combining the non-condensable gases and introducing the combined gases into a gas separator, introducing separated sulfur dioxide into a thionyl chloride synthesis reactor, and introducing separated chlorine gas into a thionyl chloride synthesis kettle, which is specifically as follows:
a. condensing the thionyl chloride mixed gas in a crude product condenser, wherein the specific conditions of the condensation are about 35 ℃, the content of thionyl chloride in the obtained condensation product is 68%, the content of sulfur dichloride is 25%, chlorine is 4%, and sulfur dioxide is 3%, and the non-condensable gas is extracted by a gas one-way conveying device such as a liquid injection device and is conveyed into a gas separator;
b. and (3) rectifying the sulfurized crude thionyl chloride in a rectifying tower to obtain thionyl chloride, a mixed high-boiling substance and tail gas, wherein the tail gas contains sulfur dioxide (about 45%), thionyl chloride (about 48%), sulfur dichloride (about 5%) and chlorine (about 2%). Discharging the mixed high-boiling-point substance from the tower to directly reach the kettle, and then sending the mixed high-boiling-point substance to a sulfur dichloride synthesis kettle through a pump to complete liquid phase circulation. The tail gas mainly comprises sulfur dioxide and chlorine gas which are sent into a gas separator through a gas one-way conveying device such as a liquid spraying device;
c. condensing the thionyl chloride mixed gas in a crude product condenser, wherein the specific conditions of condensation are about 35 ℃, the content of thionyl chloride in the obtained condensation product is 68%, the content of sulfur dichloride is 25%, chlorine is 4% and sulfur dioxide is 3%, introducing the condensation product into a crude product receiving tank of thionyl chloride for degassing and purification, and conveying the non-condensable gas generated by degassing and purification into a gas separator through a gas one-way conveying device such as a liquid spraying device;
after the non-condensable gas generated by the three components is introduced into the gas separator, the adsorbent in the adsorption device in the gas separator absorbs the sulfur dioxide in the non-condensable gas but does not absorb chlorine, so that the sulfur dioxide and the chlorine are separated, the chlorine passes through the adsorption device and is directly introduced into the sulfur dichloride synthesis kettle, the adsorbent which adsorbs the sulfur dioxide periodically enters the desorption device, the desorption device desorbs the adsorbed sulfur dioxide by an ultrasonic method, and then the desorbed sulfur dioxide enters the thionyl chloride synthesis kettle, so that gas phase circulation is completed.
The adsorbent described in this embodiment is a liquid phase adsorbent, specifically at least one of a saturated salt solution or an organic alcohol amine solution.
Example 8
The embodiment describes a method for fully extracting non-condensable gas by a gas one-way conveying device, wherein the non-condensable gas extracted from a crude product condenser returns to the gas one-way conveying device through a crude product receiving groove, so that gas phase circulation is completed, and the method specifically comprises the following steps:
and after the thionyl chloride crude product is condensed, the condensed thionyl chloride crude product enters a gas-liquid separator, the gas one-way conveying device extracts non-condensable gas in the gas-liquid separator, and after the extracted non-condensable gas is introduced into the thionyl chloride crude product receiving tank again, the non-condensable gas in the crude product receiving tank is extracted by the gas one-way conveying device and conveyed to the gas separator.
The non-condensable gas in the gas-liquid separator enters the crude product receiving groove again, and the non-condensable gas and the liquid phase in the crude product receiving groove are subjected to a gas-liquid mass transfer exchange process once again, so that thionyl chloride doped in the non-condensable gas extracted from the gas-liquid separator is absorbed by the liquid phase in the crude product receiving groove, a small amount of sulfur dioxide and chlorine in the crude product receiving groove are brought out by the non-condensable gas introduced into the gas-liquid separator and conveyed into the gas-liquid separator, an adsorption device and a desorption device are arranged in the gas-liquid separator, the non-condensable gas conveyed by the gas one-way conveying device enters the adsorption device, an adsorbent in the adsorption device absorbs the sulfur dioxide in the non-condensable gas without absorbing the chlorine, so that the sulfur dioxide and the chlorine are separated, the chlorine is directly introduced into the sulfur dichloride synthesis kettle after passing through the adsorption device, and the adsorbent which absorbs the sulfur dioxide periodically enters the desorption device, the desorption device removes the absorbed sulfur dioxide by an ultrasonic or water washing method, and then the sulfur dioxide removed by desorption enters a thionyl chloride synthesis kettle, thereby completing gas phase circulation.
Therefore, the non-condensable gas generated in the production process of the thionyl chloride is fully extracted by utilizing the reciprocating circulation of the gas one-way conveying device between the crude product condenser and the crude product receiving groove, the pressure of a rectifying tower for subsequent rectification and purification is convenient to control, and the utilization rate of raw materials is improved.
Example 9
In order to illustrate the advantages of producing thionyl chloride using the gas phase circulation apparatus and method of the present invention, this example describes the following specific method after the cycle of 72 hours from the start of raw material input to the whole thionyl chloride production process:
(1) synthesis of Sulfur monochloride (S)2Cl2): adding sulfur powder into a gas-solid synthesizer, and introducing chlorine to prepare liquid sulfur monochloride, wherein the temperature in a reaction kettle is controlled at 30-80 ℃;
(2) synthesis of Sulfur dichloride (SCl)2): reacting liquid sulfur monochloride and chlorine gas in a sulfur dichloride synthesis kettle, wherein one part of the liquid sulfur monochloride comes from products generated in the sulfur monochloride reaction kettle, the other part of the liquid sulfur monochloride comes from liquid-phase high-boiling-point components removed from a rectifying tower, and the volume ratio of the chlorine gas to the liquid sulfur monochloride is 150: (0.15-0.25), the reaction temperature is controlled to be 60-85 ℃, and the generated SCl2And excess Cl2The mixed gas is discharged from a gas outlet, the pressure in the sulfur dichloride synthesis kettle is controlled to be 0.01-0.10 MPa, and the pressure P1 at the gas outlet of the sulfur dichloride synthesis kettle is controlled to be 0.01-0.02 MPa;
(3) synthesis of thionyl chloride (SOCl)2): introducing the mixed gas discharged from the sulfur dichloride synthesis kettle into a thionyl chloride synthesis kettle, and simultaneously introducing metered sulfur dioxide gas into a thionyl chloride crude product synthesis kettle, wherein the unreacted chlorine gas, the generated sulfur dichloride and the metered sulfur dioxide are Cl2：SO2：S2Cl2Adding into Chlorophonium at a ratio of 150:100:0.20In the sulfone synthesis kettle, the reaction temperature is controlled to be 160-250 ℃, the pressure is controlled to be 0.10-0.25 MPa, and the pressure P2 at the air outlet of the thionyl chloride crude product synthesis kettle is 0.01-0.02 MPa;
(4) condensation of crude thionyl chloride: introducing mixed gas generated by a thionyl chloride synthesis kettle into a thionyl chloride crude product condenser, setting the condensation temperature to be less than or equal to 35 ℃, feeding the condensed crude product into a gas-liquid separator, feeding the condensed liquid-phase thionyl chloride crude product into a thionyl chloride crude product receiving tank, and feeding non-condensed non-condensable gas into a gas separator through a gas one-way conveying device;
(5) receiving a thionyl chloride crude product: introducing a condensation product, namely a thionyl chloride crude product, generated in a thionyl chloride crude product condenser into a crude product receiving tank, controlling the temperature of the crude product receiving tank to be 60-80 ℃ and the pressure to be 0.10-0.25 MPa, degassing and purifying the thionyl chloride crude product in the crude product receiving tank to obtain thionyl chloride after purification, and extracting low-boiling-point substances into a gas separator by using a gas one-way conveying device;
(6) and (3) sulfur preparation reaction: introducing the purified product generated by the degassing purification kettle into a sulfur preparation kettle, and performing sulfur preparation reaction under normal pressure, wherein the temperature in the sulfur preparation kettle is controlled to be 60-80 ℃, and the sulfur is added in an amount which is 70-80% of the sulfur amount required by complete reaction under normal pressure.
Wherein, the product after the crude product is condensed contains a large amount of sulfur dichloride gas, but the boiling point of the sulfur dichloride is low (59 ℃), and the sulfur dichloride is difficult to separate from the thionyl chloride, so the sulfur dichloride with low boiling point needs to be converted into the sulfur monochloride with high boiling point, and the sulfur monochloride is convenient to separate from the thionyl chloride; although sulfur dichloride can be converted into sulfur monochloride by adding sulfur into a sulfur preparation kettle to react with sulfur dichloride, sulfur for industrial production often contains moisture, and thionyl chloride is easily decomposed by water, so that if sulfur contains moisture during the sulfur preparation reaction, the decomposition of thionyl chloride is easily caused, and the purity and yield of thionyl chloride are affected. Therefore, it is necessary to dry sulfur during the sulfur-blending reaction. The method for adding sulfur in the sulfur preparation kettle provided by the embodiment comprises the following steps: the selected sulfur blocks and the desiccant calcium chloride particles are crushed together, the crushed particles reach 30-50 meshes, and the crushed mixed powder is sent into a sulfur preparation kettle for sulfur preparation reaction. Preferably, the weight ratio of the drying agent to the sulfur block is (3-5): 1.
(7) Rectification and purification: and introducing the product of the sulfur-blending reaction into a rectifying device for rectification and purification, and simultaneously carrying out excessive vulcanization in the rectifying device, wherein the non-condensable gas is conveyed into a gas separator through a gas one-way conveying device, and the condensed liquid phase is a thionyl chloride finished product.
The invention adopts a three-stage rectification mode to carry out rectification and purification on the product of the sulfur-matching reaction so as to obtain a reaction product with higher purity, and the specific rectification mode is the same as that of the embodiment 1.
Example 10
This example describes a method in which non-condensable gases generated by a crude product condenser, a rectifying tower, and a crude product receiving tank in the present invention are all used as a part of a gas raw material source, and are combined and introduced into a gas separator, separated sulfur dioxide is introduced into a thionyl chloride synthesis reactor, and separated chlorine is introduced into a thiodichloride synthesis kettle, so as to complete gas phase circulation, and other processes are the same as those in example 9, and the specific method is as follows:
and the crude product is condensed and then enters a gas-liquid separator, the gas one-way conveying device extracts the non-condensable gas in the gas-liquid separator, and after the extracted non-condensable gas is introduced into the crude product receiving tank of the thionyl chloride again, the gas one-way conveying device extracts the non-condensable gas in the crude product receiving tank and conveys the non-condensable gas to the gas separator.
The non-condensable gas in the gas-liquid separator enters the crude product receiving groove again, and the non-condensable gas and the liquid phase in the crude product receiving groove are subjected to a gas-liquid mass transfer exchange process once again, so that thionyl chloride doped in the non-condensable gas extracted from the gas-liquid separator is absorbed by the liquid phase in the crude product receiving groove, a small amount of sulfur dioxide and chlorine in the crude product receiving groove are brought out by the non-condensable gas introduced into the gas-liquid separator and conveyed into the gas-liquid separator, an adsorption device and a desorption device are arranged in the gas-liquid separator, the non-condensable gas conveyed by the gas one-way conveying device enters the adsorption device, an adsorbent in the adsorption device absorbs the sulfur dioxide in the non-condensable gas without absorbing the chlorine, so that the sulfur dioxide and the chlorine are separated, the chlorine is directly introduced into the sulfur dichloride synthesis kettle after passing through the adsorption device, and the adsorbent which absorbs the sulfur dioxide periodically enters the desorption device, the desorption device removes the absorbed sulfur dioxide by an ultrasonic or water washing method, and then the sulfur dioxide removed by desorption enters a thionyl chloride synthesis kettle, thereby completing gas phase circulation.
Comparative example 1
According to the cyclic production process of CN10142502B in the prior art, the non-condensable gas generated by a crude product condenser, a rectifying tower and a crude product receiving tank is used as a part of a gas raw material source, and is directly introduced into a thionyl chloride synthesis reactor for cyclic utilization without separation, thereby completing the gas phase cycle method. The method comprises the following specific steps:
a. condensing the thionyl chloride mixed gas in a crude product condenser, wherein the specific conditions of the condensation are about 35 ℃, the content of thionyl chloride in the obtained condensation product is 68%, the content of sulfur dichloride is 25%, chlorine is 4%, and sulfur dioxide is 3%, and the non-condensable gas is extracted by a gas one-way conveying device such as a liquid injection device and is conveyed into a thionyl chloride synthesis reactor;
b. and (3) rectifying the sulfurized crude thionyl chloride in a rectifying tower to obtain thionyl chloride, a mixed high-boiling substance and tail gas, wherein the tail gas contains sulfur dioxide (about 45%), thionyl chloride (about 48%), sulfur dichloride (about 5%) and chlorine (about 2%). Discharging the mixed high-boiling-point substance from the tower to directly reach the kettle, and then sending the mixed high-boiling-point substance to a sulfur dichloride synthesis kettle through a pump to complete liquid phase circulation. The tail gas mainly comprises sulfur dioxide and chlorine gas which are sent into the thionyl chloride synthesis reactor through a gas one-way conveying device such as a liquid spraying device;
c. and (2) condensing the thionyl chloride mixed gas in a crude product condenser, wherein the specific conditions of condensation are about 35 ℃, the content of thionyl chloride in the obtained condensation product is 68%, the content of sulfur dichloride is 25%, chlorine is 4% and sulfur dioxide is 3%, introducing the condensation product into a crude product receiving tank of thionyl chloride for degassing and purification, and feeding non-condensable gas generated by degassing and purification into a thionyl chloride synthesis reactor through a gas one-way conveying device so as to finish gas phase circulation.
The one-way gas conveying device used in the prior art is a diaphragm pump.
Comparative example 2
The production process described in this example is similar to that described in example 10, except that: the sulfur adding mode to the sulfur preparation kettle is different, and the specific method is as follows:
introducing the purified product generated by the degassing and purifying kettle into a sulfur preparation kettle, carrying out sulfur preparation reaction under normal pressure, controlling the temperature in the sulfur preparation kettle to be 60-80 ℃, adding sulfur blocks into the sulfur preparation kettle, wherein the adding amount of sulfur is 70-80% of the sulfur amount required by complete reaction, and reacting sulfur dichloride contained in the crude product after the sulfur preparation reaction with sulfur to generate sulfur monochloride with higher boiling point.
Example 11
As shown in fig. 1 and fig. 2, the present embodiment provides a gas phase circulation apparatus for producing thionyl chloride, specifically, including the following apparatuses:
the device comprises a sulfur dichloride synthesis kettle 1, a thionyl chloride synthesis kettle 2, a sulfur preparation kettle 3, a crude product condenser 4, a gas-liquid separator 5, a crude product receiving tank 6, a liquid injection device 7, a circulating pump 8, a rectifying kettle 9, a rectifying tower 10, a finished product condenser 11 and a gas separator 12, wherein an adsorption device 13 and a desorption device 14 are arranged inside the gas separator 12, the adsorption device comprises an absorption tank, an input pipeline 15, a connecting pipeline 16, a chlorine output pipeline 17 and a sulfur dioxide output pipeline 18, an adsorbent is arranged in the absorption tank, one end of the input pipeline 15 is connected with a gas one-way conveying device, the other end of the input pipeline is connected with the absorption tank, one end of the chlorine output pipeline 17 is connected with the absorption tank, and the other end of the; one end of the connecting pipeline 16 is connected with the absorption tank, and the other end is connected with the desorption device 14; in the desorption device, the absorbent discharged from the absorption pool is desorbed sulfur dioxide gas through desorption, and the desorbed sulfur dioxide gas is conveyed to the thionyl chloride synthesis kettle.
Preferably, the one-way gas conveying device adopted in the embodiment is a liquid spraying device.
Preferably, a constant temperature control box 19 is arranged outside the rectifying tower 10, the constant temperature control box 19 is connected with a finished product condenser, condensed liquid discharged from the finished product condenser 11 is introduced into the constant temperature control box 19, a heating device 20 and a temperature detector are further arranged on the constant temperature control box 19, and a low temperature liquid storage box 21 is further connected on the constant temperature control box 19. Preferably, the thermostatic control box 19 is of an annular structure and is wrapped in the middle of the rectifying tower 10, and the height of the thermostatic control box 19 is smaller than that of the rectifying tower 10.
Preferably, the constant temperature control box 19 is connected with the condenser, a first valve 22 is arranged at the connecting part, a low-temperature liquid inlet and a second valve 22 for controlling the low-temperature liquid to enter the constant temperature control box are arranged near the connecting part of the constant temperature control box 19 and the finished product condenser 11, so that the low-temperature liquid storage box 21 is communicated with the constant temperature control box 19, a liquid outlet 24 is arranged on one side far away from the low-temperature liquid inlet, and a temperature control device is arranged on the constant temperature control box. The temperature control device comprises two temperature detectors and a heating device 20, wherein a first temperature detector 25 is arranged at the middle part of the constant temperature control box 19 close to the rectifying tower, and a second temperature detector 26 is arranged at the connecting part of the constant temperature control box and the condenser.
Generally, the constant-temperature rectification temperature range of the middle part of the rectification tower is set to be 78-85 ℃, and when the temperature detected by the first temperature detector is lower than 78 ℃, the heating device starts to heat the liquid in the constant-temperature control box. Preferably, the second detector also starts the temperature detection of the condensed liquid, when the temperature of the condensed liquid is detected to be higher than the temperature detected by the first temperature detector, the temperature control device controls the first valve to be opened, the condensed liquid enters the thermostatic control box and is used for adjusting the temperature of the liquid in the thermostatic control box, namely, the temperature in the thermostatic control box can be adjusted and increased through the high-temperature condensed liquid, and the temperature can also be controlled and increased through the heating device. When the temperature detected by the first temperature detector is higher than 85 ℃, the second valve is opened, and the low-temperature liquid enters the constant-temperature control box and is used for reducing the temperature of the liquid in the constant-temperature control box, so that the temperature of the liquid in the constant-temperature control box can be always kept in a set range, and the high-efficiency rectification of the finished product of thionyl chloride is realized.
Further, the control steps using the constant temperature control method include:
s1: the temperature T1 of the middle part of the rectifying tower is detected by a first temperature detector, and whether the temperature T1 of the middle part of the rectifying tower is less than a preset temperature threshold value T is judgedaIf yes, go to step S21, otherwise go to step S22;
s21: if the temperature T1 of the middle part of the rectifying tower detected by the first temperature detector is less than the preset temperature threshold value TaIf the temperature of the liquid in the constant temperature control box is higher than the set temperature, the constant temperature control box controls the heating device to heat the liquid in the constant temperature control box, and simultaneously, the second temperature detector is started;
s22: the constant temperature control box keeps a first state;
s3: detecting the condensed liquid temperature T2 by a second temperature detector, and judging whether the condensed liquid temperature T2 is greater than T1, if so, executing the step S31, otherwise, executing the step S32;
s31: if the second temperature detector detects that the temperature T2 of the condensed liquid is greater than T1, the constant temperature control box controls the first valve to be opened, and the condensed liquid enters the constant temperature control box;
s32: if the second temperature detector detects that the condensed liquid temperature T2 is not greater than T1, the first valve remains closed;
s4: the temperature T1 of the middle part of the rectifying tower is detected by a first temperature detector, and whether the temperature T1 of the middle part of the rectifying tower is larger than a preset temperature threshold value T is judgedbIf yes, go to step S51, otherwise go to step S52;
s51: if the first temperature detector detects that the temperature T1 of the middle part of the rectifying tower is greater than a preset temperature threshold value TbIf the temperature of the low-temperature liquid in the constant-temperature control box is higher than the set temperature, the second valve is opened, and the low-temperature liquid enters the constant-temperature control box;
s52: if the first temperature detector detects that the temperature T1 of the middle part of the rectifying tower is not more than the preset temperature threshold value TbThe thermostat control box remains in the first state.
Further, the first state is that the liquid in the thermostatic control box is kept unchanged, and the heating device and all valves are kept closed.
Further, the preset temperature threshold TaAnd TbAccording to the temperature control range required by the rectification device, preferably, the T is determinedaHas a value of 78 ℃ and TbThe value of (D) was 85 ℃.
The gas phase circulating device for producing thionyl chloride provided by the embodiment can effectively improve the production efficiency and the raw material utilization rate of thionyl chloride, is simple to operate and convenient to maintain, integrally forms a totally-enclosed circulating production process, cannot pollute the environment, and is favorable for popularization and application.
Experimental example 1 investigation of the influence of separation of non-condensable off-gas on the pressure inside a thionyl chloride synthesis reactor
In this experimental example, after the gas phase circulation device for producing thionyl chloride was started and the gas phase circulation process was performed for 72 hours, the pressure change in the thionyl chloride synthesis kettle, the yield of thionyl chloride, and the purity of thionyl chloride were measured, and the obtained data are shown in table 1:
TABLE 1
The comparison of this experimental example can know that, let in the synthetic cauldron of sulfur dichloride and thionyl chloride respectively after through the separation with non-condensable gas, avoid appearing the synthetic cauldron of thionyl chloride internal pressure too high, or the phenomenon that the raw materials is not enough for pressure in the synthetic cauldron of thionyl chloride remains stable at the in-process of long-term production, avoids appearing the potential safety hazard, can increase substantially the output of thionyl chloride simultaneously.
Experimental example 3 study on circulation line of gas unidirectional transportation apparatus
Measuring each index after the equipment is started for 72 hours, wherein the specific detection method comprises the following steps:
(1) sulfur dioxide: wherein the content of the sulfur dioxide is measured by adopting a method of national standard GB/T16128-1995,
(2) and (3) determination of chlorine content: the method adopts liquid chromatography and comprises the following specific steps:
a. absorbing chlorine in the mixed gas by using an aniline aqueous solution;
b. methanol and phosphoric acid are taken as mobile phases, a C18 column is taken as a separation column, aniline and 1, 3-diphenyl urea in absorption liquid are separated, liquid chromatography analysis is carried out at the wavelength of 254nm, and the peak area of the 1, 3-diphenyl urea is in direct proportion to the chlorine content;
c. measured by an external standard method.
TABLE 2
It can be seen through the contrast above that, utilize gaseous one-way conveyor in the middle of crude condenser and thionyl chloride crude receiving groove to circulate, the effectual non-condensable gas content that reduces in the thionyl chloride crude before the rectification improves rectification efficiency, can not lead to changing by a wide margin of pressure in the rectification equipment, is convenient for control rectification pressure, and then guarantees the stability of whole refining technology.
Experimental example 4 study of Sulfur addition method in Sulfur matching reaction
TABLE 3
The contents of the components in the mixture after the sulfur-matching reaction in comparative example 10 and comparative example 2 were found to be significantly reduced in comparative example 2, and it was found that the contents of thionyl chloride were reduced due to decomposition of thionyl chloride by moisture in sulfur during the sulfur-matching reaction. The sulfur and the drying agent are mixed and added, so that the introduction of moisture along with the addition of the sulfur is avoided, and the possibility of decomposition of thionyl chloride is reduced.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes may be made to the embodiment of the present invention by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (8)
1. A gas phase circulation method for producing thionyl chloride is characterized in that: the gas phase circulation is that the noncondensable gas that deviates from in crude condenser, crude receiving groove and the rectification equipment in at least one department is carried to gas separator, and chlorine after the separation lets in the synthetic cauldron of sulfur dichloride, and the sulfur dioxide after the separation lets in the synthetic cauldron of thionyl chloride crude, gas separator inside sets up adsorption equipment and desorption device, set up the adsorbent in the adsorption equipment, the adsorbent is arranged in the non-condensable gas of absorption, desorption device desorbs the adsorbent after adsorbing sulfur dioxide, the adsorbent in the adsorption equipment is solid or liquid phase adsorbent, the liquid phase adsorbent is at least one kind in saturated salt water or the organic alcohol amine solution, and thionyl chloride production process includes: the method comprises the steps of synthesizing sulfur dichloride, synthesizing a crude product of thionyl chloride, condensing the crude product of thionyl chloride, receiving the crude product of thionyl chloride, carrying out sulfur-blending reaction and rectifying purification, arranging a constant temperature control box (19) outside a rectifying tower, connecting the constant temperature control box (19) with a finished product condenser, introducing condensed liquid discharged from the finished product condenser (11) into the constant temperature control box (19), arranging a heating device (20) and a temperature detector on the constant temperature control box (19), connecting a low-temperature liquid storage box (21) on the constant temperature control box (19), connecting the constant temperature control box (19) with the finished product condenser, arranging a first valve (22) at a connecting part, arranging a low-temperature liquid inlet near the connecting part of the constant temperature control box (19) and the finished product condenser (11) and a second valve (23) for controlling the low-temperature liquid to enter the constant temperature control box, so that the low-temperature liquid storage box (21) is communicated with the constant temperature control box (19, a liquid outlet (24) is arranged on one side far away from a low-temperature liquid inlet, a temperature control device is arranged on the constant temperature control box, the temperature control device comprises two temperature detectors and a heating device (20), wherein the first temperature detector (25) is arranged at the middle part of the constant temperature control box (19) close to the rectifying tower, the second temperature detector (26) is arranged at the connecting part of the constant temperature control box and the condenser, the constant temperature rectifying temperature range of the middle part of the rectifying tower is set to be 78-85 ℃, when the temperature detected by the first temperature detector is lower than 78 ℃, the heating device starts to heat the liquid in the constant temperature control box, meanwhile, the second temperature detector also starts to detect the temperature of the condensed liquid, when the temperature detected by the first temperature detector is higher than the temperature detected by the first temperature detector, the temperature control device controls the first valve to be opened, the temperature of the liquid in the constant temperature control box is adjusted to the condensate liquid entering constant temperature control box, and the temperature in the constant temperature control box can be adjusted through the condensate liquid of high temperature and rise promptly, also can rise through heating device control, and when the temperature that first temperature detector detected was higher than 85 ℃, the second valve was opened, and cryogenic liquid enters into constant temperature control box for reduce the temperature of the liquid in the constant temperature control box.
2. The gas phase recycle method for thionyl chloride production according to claim 1, characterized in that: and introducing the liquid phase adsorbent after absorbing the sulfur dioxide into an ultrasonic treatment device for degassing treatment, and removing the sulfur dioxide again.
3. The gas phase recycle method for thionyl chloride production according to claim 1, characterized in that: the production process of the thionyl chloride comprises the following steps:
(1) and (3) synthesis of sulfur dichloride: reacting liquid sulfur monochloride and chlorine gas in a sulfur dichloride synthesis kettle, wherein the pressure P1 at the air outlet of the sulfur dichloride synthesis kettle is 0.01-0.02 MPa;
(2) synthesis of crude thionyl chloride: introducing mixed gas discharged from a sulfur dichloride synthesis kettle into a thionyl chloride synthesis kettle, and introducing metered sulfur dioxide gas into a thionyl chloride crude product synthesis kettle, wherein the pressure P2 of a gas outlet of the thionyl chloride crude product synthesis kettle is 0.01-0.02 MPa;
(3) condensation of crude thionyl chloride: introducing mixed gas generated by a thionyl chloride synthesis kettle into a thionyl chloride crude product condenser to obtain a condensation product, wherein non-condensable gas is sent to a gas separator;
(4) receiving a thionyl chloride crude product: introducing a condensation product generated in a thionyl chloride crude product condenser into a crude product receiving tank, degassing and purifying to obtain crude thionyl chloride, and extracting low-boiling-point substances into a gas separator by using a gas one-way conveying device;
(5) and (3) sulfur preparation reaction: introducing a purified product generated by a crude product receiving tank degassing purification kettle into a sulfur preparation kettle, and performing sulfur preparation reaction under a normal pressure state, wherein the addition amount of sulfur is 70-80% of the sulfur amount required by complete reaction;
(6) rectification and purification: and introducing the product of the sulfur-preparing reaction into a rectifying device for rectification and purification, and simultaneously carrying out excessive vulcanization in the rectifying device to finally obtain a finished product of thionyl chloride.
4. The gas phase recycle method for thionyl chloride production according to claim 3, characterized in that: the pressure P1 at the air outlet of the sulfur dichloride synthesis kettle is higher than the pressure P2 at the air outlet of the thionyl chloride crude product synthesis kettle, the height of the sulfur dichloride synthesis kettle is higher than that of the thionyl chloride synthesis kettle, and the position of the thionyl chloride crude product receiving groove is higher than that of the crude product sulfur preparation kettle.
5. The gas phase recycle method for thionyl chloride production according to claim 3, characterized in that: the position of the gas separator is higher than the position of the thionyl chloride synthesis kettle and the position of the sulfur dichloride synthesis kettle.
6. The gas phase recycle method for thionyl chloride production according to claim 3, characterized in that: the method for adding the sulfur into the sulfur preparation kettle comprises the steps of firstly selecting sulfur blocks for later use, then crushing the selected sulfur blocks and desiccant calcium chloride particles together, enabling the crushed particles to reach 30-50 meshes, and then sending the crushed mixed powder into the sulfur preparation kettle for sulfur preparation reaction.
7. The gas phase recycle method for thionyl chloride production according to claim 3, characterized in that: the gas one-way conveying device is a liquid injection device, at least one liquid injection device is arranged, and the extracted non-condensable gas is introduced into the gas separator by the liquid injection device.
8. A gaseous phase circulating device for thionyl chloride production is characterized in that: the gas phase recycle process for thionyl chloride production according to any one of claims 1 to 7, wherein the recycle apparatus comprises a thionyl chloride synthesis kettle (1), a thionyl chloride synthesis kettle (2), a sulphur preparation kettle (3), a crude product condenser (4), a crude product receiving tank (6), a liquid injection apparatus (7) and a gas separator (12), and an adsorption apparatus (13) and a desorption apparatus (14) are arranged inside the gas separator (12).
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|---|---|---|---|---|
| US2431823A (en) * | 1946-02-16 | 1947-12-02 | Pittsburgh Plate Glass Co | Manufactruing thionyl chloride |
| CN101412502B (en) * | 2008-01-18 | 2010-12-01 | 江西世龙实业股份有限公司 | Method for using gas unidirectional conveying apparatus in thionyl chloride cycle production process |
| CN100480174C (en) * | 2008-01-30 | 2009-04-22 | 江西世龙实业股份有限公司 | Gas phase circulation method in synthesis of thionyl chloride |
| CN103043620A (en) * | 2012-12-31 | 2013-04-17 | 山东凯盛新材料股份有限公司 | Method for recycling tail gas during thionyl chloride preparation |
| CN205634893U (en) * | 2016-05-06 | 2016-10-12 | 新乡瑞诚科技股份有限公司 | Synthetic for thionyl chloride mother liquor recycling utilize system |
| CN106145059A (en) * | 2016-07-04 | 2016-11-23 | 汇智工程科技有限公司 | A kind of thionyl chloride reclaims, in producing, the method that sulfur dioxide recycles |
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2018
- 2018-11-27 CN CN201811427355.3A patent/CN109485019B/en active Active
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