Evaluation device for synthesizing vinyl chloride catalyst through acetylene hydrochlorination

Abstract

The utility model belongs to the technical field of catalyst evaluation devices, and particularly relates to an evaluation device for synthesizing a vinyl chloride catalyst through acetylene hydrochlorination. Comprising a raw material gas supply system, a gas mixing system, a gas preheating system, a reaction system and a tail gas absorption system which are sequentially communicated, one path of an outlet of the tail gas absorption system is connected with a detection system, and the other path is connected with an emptying system; the raw material gas supply system comprises a hydrogen chloride gas path and an acetylene gas path, hydrogen chloride and acetylene are introduced into the gas mixing system to be mixed and then are introduced into the gas preheating system, the preheated mixed gas enters the reaction system through switching of a gas switching valve connected between an upper gas inlet and a lower gas inlet of the reaction system, and the mixed gas is subjected to catalytic reaction in the reaction system; and introducing the reacted gas into a tail gas absorption system for recovery. According to the utility model, by switching the gas switching valves of the reaction system, an up-and-down gas inlet mode is provided for the reaction system, the service life of a catalyst is prolonged, and powerful data support is provided for industrial operation process conditions.

Description

Technical Field

[0001] The utility model belongs to the technical field of catalyst evaluation devices, and in particular relates to an evaluation device for a catalyst for synthesizing vinyl chloride by acetylene hydrochlorination. Background Art

[0002] The mercury catalyst used in the calcium carbide method will be gradually replaced by low-mercury catalysts, ultra-low-mercury catalysts and even mercury-free catalysts. The development of new catalysts is a necessary prerequisite for ensuring the sustainable development of the vinyl chloride industry. The transition of new catalysts from laboratory research and development to industrial application requires a comprehensive performance evaluation, including catalyst activity, stability, selectivity, and backstage control capabilities. Catalysts developed in laboratory tests cannot accurately simulate industrial conditions, and the use of industrial side lines for catalyst screening is costly and poses safety risks. Therefore, a catalyst evaluation device is needed to comprehensively evaluate the catalytic performance of the catalyst at a low cost.

[0003] At present, most catalyst evaluation devices between laboratory tests and industrial side lines are operated in a single unit with a single air intake method, which deviates greatly from the actual industrial operating parameters. In addition, due to the differences in the properties of the catalyst's active components and additives, the corresponding most suitable industrial operating conditions are different, and the catalyst has a short service life. Therefore, the device cannot meet the screening and evaluation of various types of catalysts. Utility Model Content

[0004] The problem to be solved by the utility model is: how to extend the service life of the catalyst in the catalyst evaluation device to the maximum extent.

[0005] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0006] The utility model provides an evaluation device for acetylene hydrochlorination synthesis of vinyl chloride catalyst, comprising a raw gas supply system, a gas mixing system, a gas preheating system, a reaction system and a tail gas absorption system which are connected in sequence, wherein one outlet of the tail gas absorption system is connected with a detection system, and the other outlet is connected with an emptying system; the raw gas supply system comprises a hydrogen chloride gas path and an acetylene gas path, the reaction system comprises an upper gas inlet and a lower gas inlet, the upper gas inlet and the lower gas inlet are connected with a gas switching valve, hydrogen chloride and acetylene are introduced into the gas mixing system for full mixing, and then introduced into the gas preheating system for preheating, the preheated mixed gas enters the reaction system through the switching of the gas switching valve, the mixed gas performs catalytic reaction in the reaction system, the gas after the reaction is completed is introduced into the tail gas absorption system for recovery, the gas after passing through the tail gas absorption system is introduced into the detection system for gas component detection, and the other outlet is introduced into the emptying system for emptying.

[0007] Furthermore, the raw gas supply system also includes a nitrogen gas circuit, which is connected to the gas mixing system through a two-way ball valve 1, and the on-off of the two-way ball valve 1 is used to control the flow of nitrogen entering the rear pipeline; the nitrogen gas circuit is connected to the hydrogen chloride gas circuit through a three-way ball valve 1, and the nitrogen gas circuit is connected to the acetylene gas circuit through a three-way ball valve 2, which is used for pipeline purging of the hydrogen chloride gas circuit and the acetylene gas circuit.

[0008] Furthermore, the hydrogen chloride gas circuit includes a filter 1, a pointer pressure gauge 1, a mass flowmeter 1, and a one-way check valve 1 connected in sequence; the nitrogen gas circuit includes a filter 2, a pointer pressure gauge 2, a mass flowmeter 2, and a one-way check valve 2 connected in sequence; the acetylene gas circuit includes a filter 3, a pointer pressure gauge 3, a mass flowmeter 3, and a one-way check valve 3 connected in sequence, and hydrogen chloride, nitrogen, and acetylene are supplied to the pipeline after being filtered.

[0009] Furthermore, the raw gas supply system also includes a backup gas circuit, which includes a filter four, a pointer pressure gauge four, a mass flow meter four, and a one-way check valve four connected in sequence. The backup gas circuit leads to the gas preheating system to ensure sufficient gas supply in the reaction system.

[0010] Furthermore, a two-way ball valve 2 is provided at the front end of the mass flow meter 4 of the standby gas circuit for controlling the flow of the standby gas into the gas preheating system.

[0011] Furthermore, the gas preheating system is an electrically heated preheating furnace.

[0012] Furthermore, the reaction system includes a front fixed bed reactor and a back fixed bed reactor, and a three-way ball valve three is arranged on the connecting pipeline between the front fixed bed reactor and the back fixed bed reactor, and the three-way ball valve three is used to switch the front fixed bed reactor and the back fixed bed reactor to be connected in series or run alone.

[0013] Furthermore, the gas switching valve connected to the front section of the air inlet end of the front fixed bed reactor is four-way valve one, and the gas switching valve connected to the front section of the air inlet end of the rear fixed bed reactor is four-way valve two. The four-way valve one is used for switching the air inlet between the upper air inlet and the lower air inlet of the front and rear fixed bed reactors, and the four-way valve two is used for switching the air inlet between the upper air inlet and the lower air inlet of the rear fixed bed reactor.

[0014] Furthermore, four-way valve 2 is connected to exhaust gas absorption system 1, and exhaust gas absorption system 1 includes water washing bottle 1, alkali washing bottle 1 and dryer 1 connected in sequence; four-way valve 1 is connected to exhaust gas absorption system 2 through three-way ball three valves, and exhaust gas absorption system 2 includes water washing bottle 2, alkali washing bottle 2 and dryer 2 connected in sequence.

[0015] Furthermore, the detection system is a chromatograph, which is used to analyze the exhaust gas composition to obtain catalyst performance data.

[0016] Compared with the prior art, the utility model has the following beneficial effects:

[0017] (1) The evaluation device for the catalyst for synthesizing vinyl chloride by acetylene hydrochlorination of the utility model can provide the reaction system with upper and lower air intake modes by switching the gas switching valve of the reaction system according to the type of mercury-free catalyst, thereby extending the service life of the catalyst to the greatest extent and providing strong data support for industrial operation process conditions.

[0018] (2) The evaluation device for the catalyst for synthesizing vinyl chloride by acetylene hydrochlorination of the utility model can realize single operation or multiple series operation of fixed bed reactors according to the switching of three-way ball valve 3. Single operation can realize rapid screening of catalysts, while multiple series operation can simulate industrial operation to the greatest extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the evaluation device for synthesizing vinyl chloride catalyst by acetylene hydrochlorination of the utility model;

[0020] Reference numerals:

[0021] 1. Filter 1; 2. Pointer pressure gauge 1; 3. Three-way ball valve 1; 4. Two-way ball valve 1; 5. Mass flow meter 1; 6. One-way check valve 2; 7. Electric heating preheating furnace; 8. Four-way valve 1; 9. Three-way ball valve 3; 10. Temperature indicator 1; 11. Front-stage fixed-bed reactor; 12. Four-way valve 2; 13. Temperature indicator 3; 14. Back-stage fixed-bed reactor; 15. Water washing bottle 1; 16. Alkali washing bottle 1; 17. Dryer 1; 18. Four-way valve 3; 19. Chromatograph; 20. Filter 2; 21. Pointer pressure gauge 2 ; 22. Mass flow meter two; 23. One-way check valve one; 24. Mixer; 25. One-way check valve four; 26. Temperature indicator two; 27. Filter three; 28. Pointer pressure gauge three; 29. ​​Three-way ball valve two; 30. Mass flow meter three; 31. One-way check valve three; 32. Filter four; 33. Two-way ball valve two; 34. Pointer pressure gauge four; 35. Mass flow meter four; 36. Temperature indicator four; 37. Water washing bottle two; 38. Alkaline washing bottle two; 39. Dryer two; 40. Filter six; 41. Filter five. DETAILED DESCRIPTION

[0022] The technical solution of the utility model will be clearly described below in conjunction with the accompanying drawings. Obviously, the described embodiments are not all embodiments of the utility model. All other embodiments obtained by ordinary technicians in this field without making creative work are within the protection scope of the utility model.

[0023] It should be noted that the terms "center", "up", "down", "horizontal", "left", "right", "front", "back", "lateral", "longitudinal", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0024] The utility model provides an evaluation device for acetylene hydrochlorination synthesis of vinyl chloride catalyst, comprising a raw gas supply system, a gas mixing system, a gas preheating system, a reaction system, and a tail gas absorption system connected in sequence, one outlet of the tail gas absorption system is connected to a detection system, and the other outlet is connected to an emptying system, and each system is connected through pipelines and valves. The working process between each system is as follows:

[0025] After the gas from the raw gas supply system is introduced into the gas mixing system, the gas mixing system fully mixes the gases and then introduces them into the gas preheating system. The gas preheating system heats the mixed gas to a specified temperature and then introduces it into the reaction system. The mixed gas undergoes a catalytic reaction process in the reaction system. The gas that has completed the reaction is introduced into the exhaust gas absorption system for recovery. Finally, the gas after passing through the exhaust gas absorption system is divided into two paths. One path is introduced into the detection system, which detects the gas composition and then obtains a catalyst performance evaluation. The other path enters the emptying system for emptying.

[0026] Specifically, Figure 1 As shown, the raw gas supply system includes a hydrogen chloride gas circuit, an acetylene gas circuit, and a nitrogen gas circuit connected in parallel. The hydrogen chloride gas circuit includes a filter 1, a pointer pressure gauge 2, a mass flow meter 5, and a one-way check valve 23 connected in sequence. The acetylene gas circuit includes a filter 27, a pointer pressure gauge 28, a mass flow meter 30, and a one-way check valve 31 connected in sequence. The nitrogen gas circuit includes a filter 20, a pointer pressure gauge 21, a mass flow meter 22, and a one-way check valve 26 connected in sequence.

[0027] The nitrogen passes through the filter 20, the pointer pressure gauge 21, the mass flow meter 22, and the one-way check valve 26 in sequence, and then enters the gas mixing system to check the air tightness of the back-end equipment.

[0028] Hydrogen chloride passes through filter 1, pointer pressure gauge 2, mass flow meter 5 and one-way check valve 23 in sequence and then enters the gas mixing system. Acetylene passes through filter 3 27, pointer pressure gauge 3 28, mass flow meter 3 30 and one-way check valve 3 31 in sequence and then enters the gas mixing system. Hydrogen chloride and acetylene are mixed in the gas mixing system.

[0029] Preferably, the nitrogen gas circuit is further divided into two circuits after passing through the pointer pressure gauge 21, one circuit is connected to a port of the three-way ball valve 3, and the other circuit is connected to a port of the three-way ball valve 29. The other two ports of the three-way ball valve 3 are respectively connected to the pipeline between the pointer pressure gauge 2 and the mass flow meter 5, and the other two ports of the three-way ball valve 29 are respectively connected to the pipeline between the pointer pressure gauge 3 28 and the mass flow meter 3 30. By adjusting the three-way ball valve 3 and the three-way ball valve 29, the nitrogen gas circuit can achieve the purge of residual gas in the hydrogen chloride gas circuit and the acetylene gas circuit.

[0030] Preferably, a two-way ball valve 4 is provided on the front section nitrogen gas pipeline of the mass flow meter 22, and the on-off of the two-way ball valve 4 is used to control the flow rate of nitrogen entering the rear section pipeline.

[0031] The raw gas system also includes a backup gas circuit to ensure sufficient gas supply in the device of this embodiment. The backup gas circuit includes a filter 432, a pointer pressure gauge 434, a mass flow meter 435, and a one-way check valve 425 connected in sequence. The backup gas passes through the filter 432, the pointer pressure gauge 434, the mass flow meter 435, and the one-way check valve 425 and then enters the gas preheating system.

[0032] Preferably, a two-way ball valve 2 33 is provided on the upstream pipeline of the mass flowmeter 4 35, and the on-off of the two-way ball valve 2 33 is used to control the flow rate of the backup gas entering the rear section of the pipeline.

[0033] The gas mixing system is a mixer 24. After the raw gas is mixed in the mixer 24, the mixed gas is introduced into the gas preheating system.

[0034] The gas preheating system is an electric preheating furnace 7. After the mixed gas is heated to a specified temperature in the electric preheating furnace 7, the preheated mixed gas enters the reaction system through a gas switching valve.

[0035] The reaction system comprises a front fixed bed reactor 11 and a back fixed bed reactor 14. The front fixed bed reactor 11 and the back fixed bed reactor 14 can be operated individually or in series.

[0036] A gas switching valve is connected to the front end of each of the air inlets of the foreground fixed bed reactor 11 and the background fixed bed reactor 14. The gas switching valve connected to the foreground fixed bed reactor 11 is a four-way valve 8, which is used for switching the air inlet between the upper air inlet and the lower air inlet of the foreground fixed bed reactor 11; the gas switching valve connected to the background fixed bed reactor 14 is a four-way valve 2 12, which is used for switching the air inlet between the upper air inlet and the lower air inlet of the background fixed bed reactor 14.

[0037] Preferably, the front fixed bed reactor 11 is started up by oil bath heating, which can quickly remove heat to avoid excessive local temperature and deactivation of the catalyst; the back fixed bed reactor 14 is electrically heated to achieve temperature control while keeping the cost as low as possible.

[0038] The electric heating preheating furnace 7 is connected to the front fixed bed reactor 11, the first port of the four-way valve 8 is connected to the electric heating preheating furnace 7, the second port of the four-way valve 8 is connected to the upper air inlet of the front fixed bed reactor 11, and the fourth port of the four-way valve 8 is connected to the lower air inlet of the front fixed bed reactor 11.

[0039] The third port of four-way valve 18 is connected to the first port of four-way valve 2 12, the second end of four-way valve 2 12 is connected to the upper air inlet of the background fixed bed reactor 14, the fourth port of four-way valve 2 12 is connected to the lower air inlet of the background fixed bed reactor 14, and the third port of four-way valve 2 12 is connected to the tail gas absorption system 1.

[0040] The two ends of the three-way ball valve 3 9 are connected between the third port of the four-way valve 1 8 and the first port of the four-way valve 2 12 , and the other end of the three-way ball valve 3 9 is connected to the tail gas absorption system 2.

[0041] The three-way ball valve 39 is used to switch whether the front fixed bed reactor 11 and the back fixed bed reactor 14 are operated in series. When the three-way ball valve 39 is switched to the front fixed bed reactor 11 and the back fixed bed reactor 14 are in series, the reactor state in industrial production can be truly simulated, and the gas after the catalytic reaction between the front fixed bed reactor 11 and the back fixed bed reactor 14 is discharged to the tail gas absorption system 1 for absorption. The tail gas absorption system 1 includes a water washing bottle 15, an alkali washing bottle 16, and a dryer 17 connected in sequence.

[0042] When the three-way ball valve 39 is switched to the state where the front fixed bed reactor 11 is connected to the tail gas absorption system 2, only the front fixed bed reactor 11 is in operation, and the gas after the catalytic reaction in the front fixed bed reactor 11 is discharged to the tail gas absorption system 2 for absorption. The tail gas absorption system 2 includes a water washing bottle 2 37, an alkali washing bottle 2 38, and a dryer 2 39 which are connected in sequence.

[0043] In order to realize rapid screening of catalysts, the utility model can operate a single fixed bed reactor. After the raw gas reacts in the front fixed bed reactor 11, the tail gas is switched through the three-way ball valve 3 9. The rear end of the front fixed bed reactor 11 is connected to the tail gas absorption system 2, which is successively used for water washing bottle 2 37, alkali washing bottle 2 38 and dryer 2 39 to remove the tail gas and treat hydrogen chloride, and then switched to the chromatograph 19 through the four-way valve 3 18 to analyze the tail gas composition and obtain the catalyst performance data.

[0044] The dryer 17 is connected to the second port of the four-way valve 3 18, the dryer 2 39 is connected to the fourth port of the four-way valve 3 18, the first port of the four-way valve 3 18 is connected to the emptying system, and the third port of the four-way valve 3 18 is connected to the detection system. The detection system is a chromatograph 19.

[0045] Therefore, the exhaust gas at the outlet of the fixed bed reactor passes through water washing bottle 15, alkali washing bottle 16, dryer 17 or water washing bottle 2 37, alkali washing bottle 2 38 and dryer 2 39 in sequence for exhaust gas removal and hydrogen chloride treatment; the treated exhaust gas is switched through four-way valve 3 18 to enter the chromatograph 19 for exhaust gas composition analysis, or is discharged.

[0046] Preferably, a filter five 41 is provided between the dryer one 17 and the four-way valve three 18, and a filter six 40 is provided between the dryer two 39 and the four-way valve three 18 to further filter out impurities in the exhaust gas discharged through the exhaust gas absorption system.

[0047] The experimental steps of the utility model are as follows:

[0048] (1) Weigh 100 mL of catalyst and place it in the constant temperature zone of the reaction tube, and connect the upper and lower ports of the reaction tube to the flanges;

[0049] (2) placing a reaction tube containing a catalyst in a foreground fixed bed reactor 11 and / or a background fixed bed reactor 14, inserting a temperature indicator 10 at the upper end of the foreground fixed bed reactor 11, inserting a temperature indicator 2 26 at the lower end of the foreground fixed bed reactor 11, and the temperature indicator 10 and the temperature indicator 2 26 are used to display the bed temperature of the foreground fixed bed reactor 11; inserting a temperature indicator 3 13 at the upper end of the background fixed bed reactor 14, inserting a temperature indicator 4 36 at the lower end of the background fixed bed reactor 14, and the temperature indicator 3 13 and the temperature indicator 4 36 are used to display the bed temperature of the background fixed bed reactor 14;

[0050] (3) connecting the upper air inlet, lower air inlet and air outlet of the front fixed bed reactor 11 and / or the back fixed bed reactor 14 to the entire device through pipelines;

[0051] (3) nitrogen is introduced to perform airtightness leak detection on the device, and then a temperature rise program is set to dry the catalyst. The drying time is 0.5-5 hours at a constant temperature, and the tail gas is switched to the discharge state through the four-way valve 18;

[0052] (4) After drying, switch to hydrogen chloride for activation treatment. After activation for 0.5-5h, switch to a mixture of hydrogen chloride and acetylene for reaction. The tail gas of the reaction is switched to a chromatograph for analysis via a four-way valve 18.

[0053] The above technical features constitute the best implementation example of the present utility model, which has strong adaptability and best implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the needs of different situations.

[0054] Finally, it should be noted that the above content is only used to illustrate the technical solution of the utility model, rather than to limit the protection scope of the utility model. Simple modifications or equivalent substitutions of the technical solution of the utility model by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the utility model.

Claims

1. An evaluation device for acetylene hydrochlorination synthesis of vinyl chloride catalyst, comprising a raw gas supply system, a gas mixing system, a gas preheating system, a reaction system, and a tail gas absorption system connected in sequence, wherein one outlet of the tail gas absorption system is connected to a detection system, and the other outlet is connected to an emptying system, characterized in that: The raw gas supply system includes a hydrogen chloride gas line and an acetylene gas line. The reaction system has an upper gas inlet and a lower gas inlet, and the upper gas inlet and the lower gas inlet are connected with a gas switching valve. After hydrogen chloride and acetylene are introduced into the gas mixing system for full mixing, they are introduced into the gas preheating system for preheating. The preheated mixed gas enters the reaction system through the switching of the gas switching valve. The mixed gas undergoes a catalytic reaction in the reaction system. The gas after the reaction is introduced into the tail gas absorption system for recovery. The gas after passing through the tail gas absorption system is introduced into the detection system for gas composition detection in one way and into the exhaust system for exhaust in the other way.

2. The evaluation device for the catalyst for synthesizing vinyl chloride by acetylene hydrochlorination according to claim 1, characterized in that: The raw material gas supply system also includes a nitrogen gas circuit, which is connected to the gas mixing system through a two-way ball valve.

3. The evaluation device for the catalyst for synthesizing vinyl chloride by acetylene hydrochlorination according to claim 2, characterized in that: The nitrogen gas circuit is connected to the hydrogen chloride gas circuit through a three-way ball valve 1, and the nitrogen gas circuit is connected to the acetylene gas circuit through a three-way ball valve 2.

4. The evaluation device for the catalyst for synthesizing vinyl chloride by acetylene hydrochlorination according to claim 2, characterized in that: The hydrogen chloride gas circuit includes a filter 1, a pointer pressure gauge 1, a mass flowmeter 1, and a one-way check valve 1 which are connected in sequence; the nitrogen gas circuit includes a filter 2, a pointer pressure gauge 2, a mass flowmeter 2, and a one-way check valve 2 which are connected in sequence; the acetylene gas circuit includes a filter 3, a pointer pressure gauge 3, a mass flowmeter 3, and a one-way check valve 3 which are connected in sequence; the raw gas supply system also includes a spare gas circuit, which includes a filter 4, a pointer pressure gauge 4, a mass flowmeter 4, and a one-way check valve 4 which are connected in sequence, and the spare gas circuit leads to the gas preheating system.

5. The evaluation device for the catalyst for synthesizing vinyl chloride by acetylene hydrochlorination according to claim 4, characterized in that: A two-way ball valve 2 is arranged at the front end of the mass flow meter of the standby gas circuit.

6. The evaluation device for the catalyst for synthesizing vinyl chloride by acetylene hydrochlorination according to claim 1, characterized in that: The gas preheating system is an electrically heated preheating furnace.

7. The evaluation device for the catalyst for synthesizing vinyl chloride by acetylene hydrochlorination according to claim 1, characterized in that: The reaction system includes a front fixed bed reactor and a back fixed bed reactor. A three-way ball valve 3 is arranged on the connecting pipeline between the front fixed bed reactor and the back fixed bed reactor. The three-way ball valve 3 is used to switch the front fixed bed reactor and the back fixed bed reactor to be connected in series or run alone.

8. The evaluation device for the catalyst for synthesizing vinyl chloride by acetylene hydrochlorination according to claim 7, characterized in that: The gas switching valve connected to the front section of the air inlet end of the foreground fixed bed reactor is four-way valve one, and the four-way valve one is used for switching the air inlet between the upper air inlet and the lower air inlet of the foreground fixed bed reactor; the gas switching valve connected to the front section of the air inlet end of the background fixed bed reactor is four-way valve two, and the four-way valve two is used for switching the air inlet between the upper air inlet and the lower air inlet of the background fixed bed reactor.

9. The evaluation device for the catalyst for synthesizing vinyl chloride by acetylene hydrochlorination according to claim 8, characterized in that: The four-way valve 2 is connected to the tail gas absorption system 1, and the tail gas absorption system 1 includes a water washing bottle 1, an alkali washing bottle 1 and a dryer 1 connected in sequence; the four-way valve 1 is connected to the tail gas absorption system 2 through the three-way ball valve 3, and the tail gas absorption system 2 includes a water washing bottle 2, an alkali washing bottle 2 and a dryer 2 connected in sequence.

10. The evaluation device for the catalyst for synthesizing vinyl chloride by acetylene hydrochlorination according to claim 9, characterized in that: The detection system is a chromatograph, which is used to analyze the exhaust gas composition to obtain catalyst performance data.

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