Dimethyl disulfide production device

Abstract

The invention discloses a dimethyl disulfide production device, and belongs to the technical field of chemical engineering, the dimethyl disulfide production device comprises a disulfide reactor, the disulfide reactor is a fixed bed reactor and comprises a catalyst layer and a tower kettle, the catalyst layer is provided with a cooling coil used for removing heat, and the tower kettle is provided with a heating coil used for preheating raw materials; the system further comprises a circulating pipeline, a circulating pipeline inlet and a circulating pipeline outlet; a circulating pump and a first filter for filtering solid sulfur in the disulfide reactor are arranged on the circulating pipeline; and the top of the disulfide reactor is also provided with a separator for separating gas phase and liquid phase in the disulfide reactor. Sulfur is used as an oxidizing agent to produce dimethyl disulfide, generated hydrogen sulfide is recovered, and the method is safer and more environmentally friendly.

Description

Technical Field

[0001] The present invention relates to the field of chemical engineering technology, and in particular to a dimethyl disulfide production device. Background Art

[0002] Dimethyl disulfide (DMDS) is an important chemical product, which can be widely used in the preparation of intermediates for agricultural pesticides; in the petroleum industry, it can be used as an anti-corrosion agent and anti-coking agent for ethane cracking, a sulfurizing agent in gasoline hydrocatalysis, and an inhibitor for the hydrogenolysis of benzene ring dehydroxylation reaction; in the rubber industry, it can be used as a solvent, a regenerant, a softening agent, a plasticizer, etc.; in addition, DMDS can also be used as a fuel, a lubricating additive, and an inhibitor for some organic chemical reactions.

[0003] Currently, there are two production methods for dimethyl disulfide: the dimethyl sulfate method and the methanethiol oxidation method. Among them, the dimethyl sulfate method has higher production costs, more pollutant emissions, and a relatively backward process route. The methanethiol oxidation method can be divided into the oxygen-enriched air oxidation method and the sulfur oxidation method according to different oxidants. Now, a dimethyl disulfide production device is provided, and this device uses sulfur as an oxidant, and the reaction is more mild and controllable. Summary of the Invention

[0004] The purpose of the present invention is to provide a dimethyl disulfide production device, which produces dimethyl disulfide using sulfur as an oxidant and simultaneously recovers the generated hydrogen sulfide.

[0005] To achieve the above-mentioned invention purpose, the present invention adopts the following technical solutions:

[0006] A dimethyl disulfide production device provided by the present invention includes a disulfide reactor. The disulfide reactor is a fixed-bed reactor, which includes a catalyst layer and a tower kettle. The catalyst layer is provided with cooling coils for heat removal, and the tower kettle is provided with heating coils for preheating raw materials; it also includes a circulation pipeline, a circulation pipeline inlet, and a circulation pipeline outlet. A circulation pump and a first filter for filtering solid sulfur in the disulfide reactor are provided on the circulation pipeline; a separator for separating the gas-liquid two-phase in the disulfide reactor is further provided at the top of the disulfide reactor;

[0007] Moreover, the disulfide reactor is provided with a top gas-phase material outlet, a top liquid-phase material outlet, a bottom liquid-phase material outlet, a bottom mercaptan inlet, a bottom mercaptan-containing disulfide inlet, and a middle sulfur inlet.

[0008] Furthermore, it also includes a separation tank, a polysulfide intermediate tank, a condenser, a low-temperature condenser, a condensate buffer tank, and a low-temperature condensate buffer tank; among them,

[0009] The bottom mercaptan inlet is used to introduce refined mercaptan generated from the front-end mercaptan rectification section;

[0010] The middle sulfur inlet is used for introducing the melted and filtered sulfur and the polysulfur recovered from the polysulfur intermediate tank;

[0011] The top gas-phase material outlet is used for discharging the gas-phase product after the catalytic reaction in the disulfide reactor into the condenser, and the gas-phase product is separated by the separator;

[0012] The condenser is connected to the condensate buffer tank, and the condensate buffer tank pressurizes the condensed mercaptan disulfide and sends it back to the bottom mercaptan disulfide inlet;

[0013] The uncondensed gas in the condensate buffer tank and the condenser is transported through a pipeline to the low-temperature condenser. The mercaptan disulfide after secondary condensation enters the low-temperature condensate buffer tank and is pressurized and returned to the mercaptan purification section. The uncondensed hydrogen sulfide is recovered through a pipeline;

[0014] The top liquid outlet is used for introducing the liquid-phase product separated by the separator and is connected to the separation tank for secondary separation. The gas-phase product after secondary separation enters the condenser through a pipeline, and the liquid-phase product is pressurized and enters the disulfide rectification system.

[0015] Further, it also includes a sulfur melting tank, a liquid sulfur tank and a second filter. Among them, the sulfur melting tank is connected to the liquid sulfur tank through a pipeline, and the sulfur melting tank is used for melting sulfur and making the sulfur enter the liquid sulfur tank. The liquid sulfur tank sends the melted sulfur through the second filter to the middle sulfur inlet.

[0016] Further, the shell side of the condenser is filled with a low-temperature fluid, and the low-temperature fluid is used for condensing the disulfide and part of the methanethiol in the entering gas-phase product.

[0017] Further, the temperature of the condenser is 15 - 100 °C, and the pressure of the crude hydrogen sulfide water cooler is 0.1 - 2 MpaG.

[0018] Further, the shell side of the low-temperature condenser is filled with a low-temperature fluid, and the low-temperature fluid is used for condensing the methanethiol and part of the disulfide in the entering gas-phase product.

[0019] Further, the temperature of the low-temperature condenser is -5 - 15 °C, and the pressure of the crude hydrogen sulfide water cooler is 0.1 - 2 MpaG;

[0020] Further, the low-temperature fluid includes but is not limited to circulating water, low-temperature water and chilled water, and the condenser and the low-temperature condenser are each one or more.

[0021] Furthermore, the first filter of the circulation pipeline is one in use and one in reserve, and pressure gauges showing the pressure difference are provided on both sides of the first filter. When the pressure difference is greater than the specified value, the first filter is switched; the operating temperature of the disulfide reactor is 30 - 100 °C; the operating pressure is 0.1 - 2 MpaG.

[0022] Furthermore, the sulfur melting and liquid sulfur tank is equipped with steam coils to control the temperature of the sulfur melting tank and the liquid sulfur tank at 100 - 400 °C, and the pressure of the sulfur melting tank and the liquid sulfur tank is 0.1 - 2 MpaG.

[0023] Compared with the prior art, the above one or more technical solutions have the following beneficial effects:

[0024] 1) Using the methanethiol oxidation method to produce dimethyl disulfide is more environmentally friendly than the dimethyl sulfate method.

[0025] 2) Using sulfur as an oxidant to react with mercaptan to produce dimethyl disulfide is safer than using oxygen-enriched air as an oxidant.

[0026] 3) Using sulfur as an oxidant to react with mercaptan to produce dimethyl disulfide, the hydrogen sulfide obtained after the generated gas is condensed can return to the front-end methanethiol synthesis process through its own pressure, reducing the consumption of hydrogen sulfide.

[0027] 4) Using a solution of disulfide or disulfide and polysulfide to dissolve sulfur, the reaction temperature is lower and the reaction is safer.

[0028] 5) Adding cooling coils in the middle of the catalyst layer to transfer heat and control the reaction temperature so that the reaction temperature does not change violently, increasing the service life of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings forming a part of this invention are used to provide a further understanding of the invention. The schematic embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0030] Figure 1 It is a schematic application structure diagram of the dimethyl disulfide production device in the present invention.

[0031] Figure 2 It is a schematic application principle diagram of the dimethyl disulfide production device in the present invention.

[0032] Figure 3 is Figure 1 a schematic structure diagram of the disulfide reactor in DETAILED DESCRIPTION OF THE INVENTION

[0033] To enable those skilled in the art to better understand the solution of this application, the following will clearly and completely describe the technical solutions in the embodiments of this application in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0034] It should be noted that the terms "first", "second", etc. in the description and claims of this application and the above-mentioned accompanying drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so as to describe the embodiments of this application here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0035] In addition, the terms "installation", "setting", "provided with", "connection", "connected", "socketed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or there can be internal communication between two devices, components or parts. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0036] The present invention discloses a dimethyl disulfide production device, and the dimethyl disulfide production device includes a disulfide reactor 2, a separation tank 15, a polysulfide intermediate tank 17, a sulfur melting tank 4, a liquid sulfur tank 5, a condenser 8, a low-temperature condenser 11, a condensate buffer tank 9, and a low-temperature condensate buffer tank 12;

[0037] The refined mercaptan 1 from the front-end mercaptan rectification section enters the bottom of the disulfide reactor 2. The raw material sulfur 3 enters the sulfur melting tank 4 from the battery limit, melts and then enters the liquid sulfur tank 5 by means of overflow, and then enters the second filter 7 through the liquid sulfur feeding pump 6 and then enters the disulfide reactor 2.

[0038] The product obtained from the catalytic reaction is separated by the separator 27 at the top of the disulfide reactor 2. The gaseous product enters the condenser 8 through the top gas outlet of the tower. After being condensed by the condenser 8, the mercaptan-containing disulfide enters the disulfide condensate buffer tank 9 and then returns to the disulfide reactor 2 after being pressurized by the output pump 10 of the disulfide condensate buffer tank. The gas not condensed by the condenser 8 enters the low-temperature condenser 11. The disulfide mercaptan-containing condensate obtained after condensation by the low-temperature condenser 11 enters the low-temperature condensate buffer tank 12 and then returns to the mercaptan purification section after being pressurized by the output pump 13 of the low-temperature condensate buffer tank 12. The hydrogen sulfide 14 not condensed by the low-temperature condenser 11 is recycled. The liquid-phase product separated by the separator 27 enters the separation tank 15 through overflow for further separation. The gas phase enters the condenser 8, and the liquid phase enters the disulfide rectification system after being pressurized by the output pump 16 of the separation tank;

[0039] In this embodiment, the disulfide reactor 2 is a fixed-bed reactor. A cooling coil 21 is provided in the catalyst layer for heat removal, and a heating coil 22 is provided at the bottom of the tower for preheating the raw materials before the reaction. The disulfide reactor 2 is provided with a circulation pipeline, a circulation pipeline inlet 23 and a circulation pipeline outlet 24. A first filter 25 and a circulation pump 26 are provided on the circulation pipeline for filtering the solid sulfur in the disulfide reactor 2. A separator 27 is provided at the top of the disulfide reactor 2 for separating the gas-liquid two phases in the disulfide reactor 2. The disulfide reactor 2 is provided with a top gas-phase material outlet 28, a top liquid-phase material outlet 29, a bottom liquid-phase material outlet 210, a bottom mercaptan inlet 211, a bottom mercaptan-containing disulfide inlet 212, and a middle sulfur inlet 213.

[0040] In this embodiment, the operating temperature of the disulfide reactor 2 is 30 - 100 °C; the operating pressure is 0.1 - 2 MpaG.

[0041] In this embodiment, the reaction of sulfur 3 with methyl mercaptan is realized on the basis of dimethyl disulfide (or a mixture of disulfide and polysulfide) as a solvent.

[0042] In this embodiment, the molten sulfur tank 4 and the liquid sulfur tank 5 are provided with steam coils to control the temperature of the molten sulfur tank 4 and the liquid sulfur tank 5: 100 - 400 °C, and the pressure of the molten sulfur and the liquid sulfur tank: 0.1 - 2 MpaG.

[0043] In this embodiment, the shell side of the condenser 8 is a low-temperature fluid, which is used to cool the gaseous product separated by the separator 27 at the top of the disulfide reactor 2 to condense the disulfide and part of the methyl mercaptan therein; the temperature of the condenser 8 is 15 - 100 °C, and the pressure of the crude hydrogen sulfide water cooler is 0.1 - 2 MpaG.

[0044] In this embodiment, the shell side of the low-temperature condenser 11 is a low-temperature fluid, which is used to cool the gaseous products that cannot be condensed by the condenser 8, so that methyl mercaptan and part of the disulfide are condensed; the temperature of the low-temperature condenser 11 is -5 to 15 °C, and the pressure of the crude hydrogen sulfide water cooler is 0.1 to 2 MpaG.

[0045] In this embodiment, the low-temperature fluid includes but is not limited to circulating water, low-temperature water, and chilled water, and the condenser 8 and the low-temperature condenser 11 can be one or more.

[0046] In this embodiment, the first filter 25 on the circulation pipeline is one in use and one standby, and pressure gauges are provided on both sides to measure the pressure difference. When the pressure difference is greater than the specified value, the two first filters 25 are switched for regeneration.

[0047] In this embodiment, the polysulfur recovered by the polysulfur intermediate tank 17 enters the disulfide reactor 2 through the sulfur inlet 213 in the middle.

[0048] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A dimethyl disulfide production device, characterized in that, it includes a disulfide reactor, the disulfide reactor is a fixed-bed reactor, including a catalyst layer and a tower kettle, the catalyst layer is provided with cooling coils for heat removal, and the tower kettle is provided with heating coils for preheating raw materials; it also includes a circulation pipeline and a circulation pipeline inlet and a circulation pipeline outlet, and a circulation pump and a first filter for filtering solid sulfur in the disulfide reactor are arranged on the circulation pipeline; a separator for separating the gas-liquid two-phase in the disulfide reactor is also arranged at the top of the disulfide reactor; And, the disulfide reactor is provided with a top gas-phase material outlet, a top liquid-phase material outlet, a bottom liquid-phase material outlet, a bottom mercaptan inlet, a bottom mercaptan-containing disulfide inlet, and a middle sulfur inlet.

2. The dimethyl disulfide production device according to claim 1, characterized in that, it further includes a separation tank, a polysulfide intermediate tank, a condenser, a low-temperature condenser, a condensate buffer tank and a low-temperature condensate buffer tank; wherein, the bottom mercaptan inlet is used for the refined mercaptan produced in the front-end mercaptan rectification section to enter; the middle sulfur inlet is used for the melted and filtered sulfur and the polysulfide recovered from the polysulfide intermediate tank to enter; the top gas-phase material outlet is used for discharging the gas-phase product after the catalytic reaction in the disulfide reactor to the condenser, and the gas-phase product is separated by the separator; the condenser is connected to the condensate buffer tank, and the condensate buffer tank pressurizes the condensed mercaptan-containing disulfide and sends it back to the bottom mercaptan-containing disulfide inlet; the uncondensed gas in the condensate buffer tank and the condenser is transported to the low-temperature condenser through a pipeline, the disulfide mercaptan after secondary condensation enters the low-temperature condensate buffer tank, and after being pressurized, it returns to the mercaptan purification section, and the uncondensed hydrogen sulfide is recovered through a pipeline; the top liquid-phase outlet is used for entering the liquid-phase product separated by the separator, and is connected to the separation tank for secondary separation, the gas-phase product after secondary separation enters the condenser through a pipeline, and the liquid-phase product enters the disulfide rectification system after being pressurized.

3. The dimethyl disulfide production device according to claim 2, characterized in that, it further includes a sulfur melting tank, a liquid sulfur tank and a second filter, wherein the sulfur melting tank is connected to the liquid sulfur tank through a pipeline, and the sulfur melting tank is used for melting sulfur and making sulfur enter the liquid sulfur tank, and the liquid sulfur tank sends the melted sulfur to the middle sulfur inlet after passing through the second filter.

4. The dimethyl disulfide production device according to claim 2, characterized in that, the shell side of the condenser is filled with a low-temperature fluid, and the low-temperature fluid is used for condensing disulfide and part of methyl mercaptan in the incoming gas-phase product.

5. The dimethyl disulfide production device according to claim 4, characterized in that, the temperature of the condenser is 15 - 100 °C, and the pressure of the crude hydrogen sulfide water cooler is: 0.1 - 2 MpaG.

6. The dimethyl disulfide production device according to claim 2, characterized in that, the shell side of the low-temperature condenser is filled with a low-temperature fluid, and the low-temperature fluid is used for condensing methyl mercaptan and part of disulfide in the incoming gas-phase product.

7. The dimethyl disulfide production device according to claim 6, characterized in that, The temperature of the low-temperature condenser is -5 to 15 °C, and the pressure of the crude hydrogen sulfide water cooler is 0.1 to 2 MpaG.

8. The dimethyl disulfide production device according to claim 4 or 6, characterized in that the low-temperature fluid includes but is not limited to circulating water, low-temperature water, and chilled water, and the condenser and the low-temperature condenser are each one or more.

9. The dimethyl disulfide production device according to claim 1, characterized in that the first filter on the circulation pipeline is one in use and one in reserve, and pressure gauges showing the pressure difference are provided on both sides of the first filter, and the first filter is switched when the pressure difference is greater than the specified value; the operating temperature of the disulfide reactor is 30 to 100 °C; the operating pressure is 0.1 to 2 MpaG.

10. The dimethyl disulfide production device according to claim 3, characterized in that the sulfur melting and liquid sulfur tank is provided with a steam coil to control the temperature of the sulfur melting tank and the liquid sulfur tank at 100 to 400 °C, and the pressure of the sulfur melting tank and the liquid sulfur tank is 0.1 to 2 MpaG.

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