A method for purifying sulfur dioxide and improving synthesis yield

Abstract

This invention relates to the field of chemical technology, and in particular to a method for purifying sulfur dioxide and improving synthesis yield, comprising the following steps: S1: Gas SO2 from a buffer tank enters an oil separator; S2: The oil-removed gaseous sulfur dioxide enters a drying tower #1 for drying, and then enters a drying tower #2 for further drying; S3: The oil-removed and dried gaseous SO2, along with Cl2 and S2Cl2, enters a catalyst to react and generate thionyl chloride. Compared with the prior art, the beneficial effects of this invention are: By removing oil and drying gaseous SO2, this invention solves the problem of the raw material sulfur dioxide carrying a large amount of oily substances and moisture, avoiding partial catalyst caking and deactivation, and the resulting decrease in catalyst activity, which affects the yield of thionyl chloride synthesis. The synthesis yield is increased from the original 50% to 85%, increasing production load and reducing production costs.

Description

Technical Field

[0001] This invention relates to the field of chemical technology, and in particular to a method for purifying sulfur dioxide and improving synthesis yield. Background Technology

[0002] Thionyl chloride (SOCl2) is an important fine chemical raw material for my country's national economic development. There are four domestic technologies for producing thionyl chloride: the chlorosulfonic acid method, the co-production method, the sulfur trioxide method, and the sulfur dioxide gas-phase method. The main raw materials for the sulfur dioxide gas-phase method to produce thionyl chloride are SO2, Cl2, and S2Cl2, and the reaction equation is as follows:

[0003] S2Cl2 + Cl2 → SCl2

[0004]

[0005] The raw material sulfur dioxide carries a large amount of oily substances and moisture, which can cause partial caking and deactivation of the catalyst. In addition, insufficient catalyst stability may also lead to a decrease in catalyst activity. By removing the oil and moisture from sulfur dioxide, the strength and activity of the catalyst can be improved, the service life can be extended, the yield of thionyl chloride catalytic synthesis can be increased, the production load can be increased, and the production cost can be reduced. Summary of the Invention

[0006] To address the problems mentioned in the background section, this invention provides a method for purifying sulfur dioxide and improving synthesis yield.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A method for purifying sulfur dioxide to improve synthesis yield includes the following steps:

[0009] S1: SO2 gas exiting the buffer tank enters the oil separator;

[0010] S2: The oil-removed gaseous sulfur dioxide enters drying tower #1 for drying, and then enters drying tower #2 for further drying;

[0011] S3: The oil-removed and dried gas SO2, along with Cl2 and S2Cl2, enters the catalyst to react and generate thionyl chloride.

[0012] Preferably, the degreaser contains a degreasing agent.

[0013] Preferably, the degreasing agent is a powder with a particle size of 100-200 mesh, and, calculated by mass, includes Ca[(Ba]]. 0.7 Mg 0.3 ) 1 / 3 V 2 / 3O3 powder 70-80 parts, calcium oxide 3-5 parts, sodium chloride 1-2 parts, calcined gypsum 1-3 parts.

[0014] Preferably, the Ca[(Ba 0.7 Mg 0.3 ) 1 / 3 V 2 / 3 The preparation method of O3 powder includes the following steps:

[0015] Calcium carbonate, barium oxide, and vanadium pentoxide were reacted according to the chemical formula Ca(Ba) 1 / 3 V 2 / 3 The O3 mixture was mixed in the specified proportions, ethanol was added, and the mixture was wet-milled for 24 hours, dried at 80°C for 12 hours, and calcined at 1200°C for 4 hours to obtain intermediate product A.

[0016] Magnesium oxide and vanadium pentoxide were mixed in the proportion of chemical formula MgV2O6, ethanol was added, and the mixture was wet-milled for 24 h, dried at 80 °C for 12 h, and calcined at 1200 °C for 4 h to obtain intermediate product B.

[0017] Calcium carbonate and intermediate product B are disposed of according to the chemical formula Ca(Mg) 1 / 3 V 2 / 3 The mixture of O3 was mixed in the specified proportions, ethanol was added, and the mixture was wet-milled for 24 hours, dried at 80°C for 12 hours, and calcined at 1200°C for 4 hours to obtain intermediate product C.

[0018] Intermediate products A and C are processed according to the chemical formula Ca[(Ba 0.7 Mg 0.3 ) 1 / 3 V 2 / 3 The mixture of O3 and Ca[(Ba] was treated at 600℃ for 24 h and calcined at 1550℃ for 10 h to obtain Ca[(Ba]]. 0.7 Mg 0.3 ) 1 / 3 V 2 / 3 ]O3 powder.

[0019] Preferably, in step S1, the operating pressure inside the oil separator is 0.1-0.6 MPa, and the operating temperature is 20-50℃.

[0020] Preferably, in step S2, anhydrous calcium chloride is used as a desiccant in drying towers #1 and #2.

[0021] Preferably, in step S3, activated carbon is used as the catalyst in the catalyst.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. This invention solves the problem of the raw material sulfur dioxide carrying a large amount of oily substances and moisture by removing oil and drying gas SO2, avoiding partial caking and deactivation of the catalyst, and reducing the catalyst activity, which affects the yield of thionyl chloride synthesis. The synthesis yield is increased from the original 50% to 85%, improving production load and reducing production costs.

[0024] 2. This invention employs a one-step calcination method to synthesize Ca(Ba). 1 / 3 V 2 / 3 O3 was then synthesized by stepwise calcination of Ca(Mg)2O3. 1 / 3V 2 / 3 O3, and finally Ca(Ba 1 / 3 V 2 / 3 O3 and Ca(Mg) 1 / 3 V 2 / 3 O3 was mixed and sintered to obtain Ca[(Ba 0.7 Mg 0.3 ) 1 / 3V 2 / 3 ]O3 powder, Ca[(Ba 0.7 Mg 0.3 ) 1 / 3 V 2 / 3 When O3 powder is used in combination with calcium oxide, sodium chloride, and calcined gypsum, it exhibits excellent oil absorption performance, effectively preventing a decrease in the activity of subsequent catalysts. Detailed Implementation

[0025] Unless otherwise stated, all parts in this invention are parts by weight;

[0026] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0027] Preparation Example 1

[0028] Ca[(Ba 0.7 Mg 0.3 ) 1 / 3 V 2 / 3 The preparation method of O3 powder includes the following steps:

[0029] Calcium carbonate, barium oxide, and vanadium pentoxide were reacted according to the chemical formula Ca(Ba) 1 / 3 V 2 / 3 The O3 mixture was mixed in the specified proportions, ethanol was added, and the mixture was wet-milled for 24 hours, dried at 80°C for 12 hours, and calcined at 1200°C for 4 hours to obtain intermediate product A.

[0030] Magnesium oxide and vanadium pentoxide were mixed in the proportion of chemical formula MgV2O6, ethanol was added, and the mixture was wet-milled for 24 h, dried at 80 °C for 12 h, and calcined at 1200 °C for 4 h to obtain intermediate product B.

[0031] Calcium carbonate and intermediate product B are disposed of according to the chemical formula Ca(Mg) 1 / 3 V 2 / 3 The mixture of O3 was mixed in the specified proportions, ethanol was added, and the mixture was wet-milled for 24 hours, dried at 80°C for 12 hours, and calcined at 1200°C for 4 hours to obtain intermediate product C.

[0032] Intermediate products A and C are processed according to the chemical formula Ca[(Ba 0.7 Mg 0.3 ) 1 / 3 V 2 / 3 The mixture of O3 and Ca[(Ba] was treated at 600℃ for 24 h and calcined at 1550℃ for 10 h to obtain Ca[(Ba]]. 0.7 Mg 0.3 ) 1 / 3 V 2 / 3 ]O3 powder.

[0033] Preparation Example 2

[0034] Preparation method of degreasing agent:

[0035] Calculate by mass fraction and weigh Ca[(Ba 0.7 Mg 0.3 ) 1 / 3 V 2 / 3 Mix 70-80 parts of O3 powder, 3-5 parts of calcium oxide, 1-2 parts of sodium chloride, and 1-3 parts of calcined gypsum evenly, and then pulverize into powder with a particle size of 100-200 mesh.

[0036] Example 1

[0037] A method for purifying sulfur dioxide to improve synthesis yield includes the following steps:

[0038] S1: SO2 gas exiting the buffer tank enters the oil separator;

[0039] S2: The oil-removed gaseous sulfur dioxide enters drying tower #1 for drying, and then enters drying tower #2 for further drying;

[0040] S3: The oil-removed and dried gas SO2, along with Cl2 and S2Cl2, enters the catalyst to react and generate thionyl chloride;

[0041] In step S1, the degreasing agent (obtained in preparation example 2) is provided in the degreasing device, the operating pressure in the degreasing device is 0.3 MPa, and the operating temperature is 35°C.

[0042] In step S2, anhydrous calcium chloride is used as a desiccant in drying towers #1 and #2.

[0043] In step S3, activated carbon is used as a catalyst in the catalyst.

[0044] The yield of thionyl chloride was found to be 85% after testing.

[0045] Comparative Example 1

[0046] The SO2 gas exiting the buffer tank does not enter the oil separator; it does not enter drying tower #1 or drying tower #2 for drying.

[0047] Gas SO2, as well as Cl2 and S2Cl2, directly enter the catalyst to react and generate thionyl chloride;

[0048] Activated carbon is used as a catalyst in the catalyst.

[0049] The yield of thionyl chloride was found to be 50% after testing.

[0050] Comparative Example 2

[0051] A method for purifying sulfur dioxide to improve synthesis yield includes the following steps:

[0052] The SO2 gas exiting the buffer tank does not enter the oil separator;

[0053] It goes directly into drying tower #1 for drying, and then into drying tower #2 for drying.

[0054] The dried SO2 gas, along with Cl2 and S2Cl2, enters the catalyst to react and generate thionyl chloride.

[0055] Anhydrous calcium chloride was used as a desiccant in drying towers #1 and #2.

[0056] Activated carbon is used as a catalyst in the catalyst.

[0057] The yield of thionyl chloride was found to be 62%.

[0058] Comparative Example 3

[0059] A method for purifying sulfur dioxide to improve synthesis yield includes the following steps:

[0060] The SO2 gas exiting the buffer tank enters the oil separator;

[0061] The sulfur dioxide gas after oil removal does not enter drying tower #1 or drying tower #2 for drying;

[0062] The oil-removed gas SO2, as well as Cl2 and S2Cl2, enter the catalyst to react and generate thionyl chloride;

[0063] The oil separator contains an oil-removing agent (obtained in Preparation Example 2), and the operating pressure inside the oil separator is 0.3 MPa, and the operating temperature is 35°C.

[0064] Activated carbon is used as a catalyst in the catalyst.

[0065] The yield of thionyl chloride was found to be 67% after testing.

[0066] This invention solves the problem of the raw material sulfur dioxide carrying a large amount of oily substances and moisture by removing oil and drying gas SO2, thus avoiding partial caking and deactivation of the catalyst, which reduces the catalyst activity and affects the yield of thionyl chloride synthesis. The synthesis yield is increased from the original 50% to 85%, improving production load and reducing production costs.

[0067] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for purifying sulfur dioxide and improving synthesis yield, characterized in that, Includes the following steps: S1: SO2 gas exiting the buffer tank enters the oil separator; S2: The oil-removed gaseous sulfur dioxide enters drying tower #1 for drying, and then enters drying tower #2 for further drying; S3: The oil-removed and dried gas SO2, along with Cl2 and S2Cl2, enters the catalyst to react and generate thionyl chloride; The degreasing device contains a degreasing agent, which is a powder with a particle size of 100-200 mesh, and includes Ca[(Ba] by weight. 0.7 Mg 0.3 ) 1 / 3 V 2 / 3 70-80 parts O3 powder, 3-5 parts calcium oxide, 1-2 parts sodium chloride, and 1-3 parts calcined gypsum; The Ca[(Ba 0.7 Mg 0.3 ) 1 / 3 V 2 / 3 The preparation method of O3 powder includes the following steps: Calcium carbonate, barium oxide, and vanadium pentoxide were reacted according to the chemical formula Ca(Ba) 1 / 3 V 2 / 3 The O3 mixture was mixed in the specified proportions, ethanol was added, and the mixture was wet-milled for 24 hours, dried at 80°C for 12 hours, and calcined at 1200°C for 4 hours to obtain intermediate product A. Magnesium oxide and vanadium pentoxide were mixed in the proportion of chemical formula MgV2O6, ethanol was added, and the mixture was wet-milled for 24 h, dried at 80 °C for 12 h, and calcined at 1200 °C for 4 h to obtain intermediate product B. calcium carbonate 、 Intermediate product B, according to the chemical formula Ca(Mg) 1 / 3 V 2 / 3 The mixture of O3 was mixed in the specified proportions, ethanol was added, and the mixture was wet-milled for 24 hours, dried at 80°C for 12 hours, and calcined at 1200°C for 4 hours to obtain intermediate product C. Intermediate products A and C are processed according to the chemical formula Ca[(Ba 0.7 Mg 0.3 ) 1 / 3 V 2 / 3 The mixture of O3 and Ca[(Ba] was treated at 600℃ for 24 h and calcined at 1550℃ for 10 h to obtain Ca[(Ba]]. 0.7 Mg 0.3 ) 1 / 3 V 2 / 3 ]O3 powder.

2. The method for purifying sulfur dioxide and improving synthesis yield according to claim 1, characterized in that, In step S1, the operating pressure inside the oil separator is 0.1-0.6 MPa, and the operating temperature is 20-50℃.

3. The method for purifying sulfur dioxide and improving synthesis yield according to claim 1, characterized in that, In step S2, anhydrous calcium chloride is used as a desiccant in drying towers #1 and #2.

4. The method for purifying sulfur dioxide and improving synthesis yield according to claim 1, characterized in that, In step S3, activated carbon is used as a catalyst in the catalyst.

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