Device for separating hydrogen sulfide in mercaptan or thioether and application thereof

Abstract

The invention discloses a device for separating hydrogen sulfide in mercaptan or thioether, and belongs to the field of chemical engineering, the device comprises a crude mercaptan preheater used for carrying out heat exchange on crude mercaptan and qualified purified mercaptan ether, preheating the crude mercaptan, and exporting the crude mercaptan after heat exchange and the qualified mercaptan ether; the high-pressure rectifying tower is used for rectifying the crude mercaptan subjected to heat exchange; the high-pressure rectifying tower bottom reboiler is used for heating the purified mercaptan ether liquid at the tower bottom; and the tower bottom buffer tank is used for buffering and collecting the purified mercaptan ether liquid at the tower bottom. By adding the high-pressure rectifying tower, mercaptan is left in the tower while hydrogen sulfide is recovered, pure hydrogen sulfide is obtained at the top of the tower, the amount of mercaptan returning to the reactor is reduced, and the conversion rate of the reactor is improved. The rectification pressure is increased, so that hydrogen sulfide can directly return to the front buffer tank of the reactor without using a compressor, and the energy consumption is reduced.

Description

Technical Field

[0001] The present application relates to the field of chemical technology, and in particular to a device for separating hydrogen sulfide from mercaptans or thioethers and an application thereof. Background Art

[0002] In a device for reacting methanol with hydrogen sulfide to generate mercaptan sulfide, the synthesis gas produced by the reaction passes through a condenser, and the organic phase after condensation is a mixture of methanol, mercaptan, sulfide and water. The crude mercaptan or sulfide obtained after water separation still contains some hydrogen sulfide. In the original process, the hydrogen sulfide obtained after distillation of these crude mercaptans is pressurized by a compressor and returned to the hydrogen sulfide buffer tank in front of the reactor. However, these hydrogen sulfides contain some methyl mercaptan, which not only corrodes the seal of the compressor and reduces the service life of the compressor, but also inhibits the reaction as a reactant returning to the reactor, thereby reducing the conversion rate of the raw material. Summary of the invention

[0003] The main purpose of the present application is to provide a device for separating hydrogen sulfide from mercaptans or thioethers, by adding a high-pressure distillation tower, while recovering hydrogen sulfide, mercaptans are retained in the tower, pure hydrogen sulfide is obtained at the top of the tower, the amount of mercaptans returned to the reactor is reduced, and the conversion rate of the reactor is improved. By increasing the distillation pressure, hydrogen sulfide can be directly returned to the buffer tank in front of the reactor, and a compressor is no longer needed, thereby reducing energy consumption.

[0004] To achieve the above object, the first aspect of the present invention provides a device for separating hydrogen sulfide from mercaptan ethers, the device comprising:

[0005] A crude mercaptan preheater, used for exchanging heat between crude mercaptan and qualified purified mercaptan ether to preheat the crude mercaptan;

[0006] A high-pressure distillation tower, used for distilling the crude mercaptan after heat exchange, and condensing the gas generated during the distillation process through a high-pressure distillation tower top condenser installed at the top of the high-pressure distillation tower and then leading it out from the top of the high-pressure distillation tower, and dividing the purified mercaptan ether liquid at the bottom of the high-pressure distillation tower into two outlets for leading out;

[0007] A reboiler at the bottom of the high-pressure distillation tower, used to heat the purified mercaptan ether liquid at the bottom of the tower and introduce it into the interior of the high-pressure distillation tower;

[0008] The tower bottom buffer tank is used to buffer and collect the purified mercaptan or thioether liquid at the bottom of the tower. The tower bottom buffer tank and the bottom of the high-pressure distillation tower are connected to a pipeline for ensuring the liquid level of the purified mercaptan or thioether liquid at the bottom of the high-pressure distillation tower. The qualified purified mercaptan or thioether at the top of the tower bottom buffer tank is introduced into the crude mercaptan preheater, and the bottom of the tower bottom buffer tank delivers the unqualified mercaptan or thioether in the tower bottom buffer tank to the crude mercaptan or thioether buffer tank through the tower bottom buffer tank output pump.

[0009] Preferably, a gas phase discharge outlet is provided at the top of the high-pressure distillation tower, pressure gauges are installed at the upper and lower parts of the high-pressure distillation tower, a plurality of sets of thermometers are installed along the height direction of the high-pressure distillation tower, a plurality of crude mercaptan inlets are provided at the middle part of the high-pressure distillation tower, a liquid level gauge for monitoring the highest liquid level and the lowest liquid level is provided at the lower part of the high-pressure distillation tower, and a reflux liquid inlet, a reboiler outlet pipeline connection port and two tower bottom discharge outlets are also provided at the lower part of the high-pressure distillation tower.

[0010] Preferably, the pressure gauge installed on the upper part of the high-pressure distillation tower is interlocked with the regulating valve installed on the hydrogen sulfide recovery pipeline, the thermometer installed on the top of the high-pressure distillation tower is interlocked with the regulating valve on the coolant outlet pipeline of the top condenser of the high-pressure distillation tower, the thermometer installed at the bottom of the high-pressure distillation tower is interlocked with the regulating valve on the heat source pipeline of the reboiler at the bottom of the high-pressure distillation tower, and the liquid level meter for monitoring the highest liquid level is interlocked with the regulating valve of the bottom extraction pipeline.

[0011] Preferably, the temperature of the high-pressure distillation tower is 10-150°C, and the pressure is 1.5-3MpaG; the temperature of the crude mercaptan preheater is 10-150°C, and the pressure is 1.5-3MpaG.

[0012] Preferably, the high-pressure distillation tower includes but is not limited to bulk packing and structured packing.

[0013] The second aspect of the present invention provides use of the device for separating hydrogen sulfide from mercaptan ethers described in the first aspect of the present invention in separating hydrogen sulfide from crude mercaptan.

[0014] The benefit of the present application is that: the method of the present invention adds a high-pressure distillation tower, and while recovering hydrogen sulfide, mercaptans are retained in the tower, and pure hydrogen sulfide is obtained at the top of the tower, which reduces the amount of mercaptans returned to the reactor and improves the conversion rate of the reactor. By increasing the distillation pressure, hydrogen sulfide can be directly returned to the buffer tank in front of the reactor, and a compressor is no longer needed, thereby reducing energy consumption.

[0015] The present invention has the following advantages:

[0016] 1) The high-pressure distillation tower solves the problem of mercaptan returning to the reaction system, which reduces the conversion rate of raw materials;

[0017] 2) The pressure of the high-pressure distillation tower increases, which increases the dew point of mercaptans. Conventional cooling media can be used for condensation, reducing investment.

[0018] 3) The use of current high-pressure distillation towers does not include a compressor, which solves the corrosion problem and reduces energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of this application are used to provide a further understanding of this application, so that other features, purposes and advantages of this application become more obvious. The schematic embodiment drawings and their descriptions of this application are used to explain this application and do not constitute an improper limitation on this application. In the drawings:

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 It is a process flow chart of the present invention.

[0022] Figure 3 It is a detailed diagram of a high-pressure distillation tower of the present invention.

[0023] In the above figure, 100, crude mercaptan preheater; 200, high-pressure distillation tower; 210, pressure gauge; 220, gas phase discharge outlet; 230, high-pressure distillation tower top condenser; 240, crude mercaptan inlet; 250, thermometer; 260, reflux liquid inlet; 270, liquid level gauge; 280, reboiler outlet pipeline connection port; 290, tower bottom discharge outlet; 300, high-pressure distillation tower bottom reboiler; 400, tower bottom buffer tank; 500, tower bottom buffer tank output pump. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only embodiments of a part of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present application.

[0025] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application are described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, the process, method, system, product or equipment comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0026] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0027] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0028] In addition, the terms "installed", "set", "provided with", "connected", "connected", and "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 a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. 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.

[0029] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] See also Figure 1-Figure 3 As shown, the first aspect of the present invention provides a device for separating hydrogen sulfide from mercaptan ethers, the device comprising:

[0031] A crude mercaptan preheater 100 is used to perform heat exchange between crude mercaptan and qualified purified mercaptan ether to preheat the crude mercaptan;

[0032] The high-pressure distillation tower 200 is used to distill the crude mercaptan after heat exchange, and the gas generated during the distillation process is condensed by the high-pressure distillation tower top condenser 230 installed at the top of the high-pressure distillation tower 200 and discharged from the top of the high-pressure distillation tower 200, and the purified mercaptan or sulfide liquid at the bottom of the high-pressure distillation tower 200 is discharged through two outlets;

[0033] A reboiler 300 at the bottom of the high-pressure distillation tower is used to heat the purified mercaptan or sulfide liquid at the bottom of the tower and introduce it into the interior of the high-pressure distillation tower 200;

[0034] The tower bottom buffer tank 400 is used to buffer and collect the purified mercaptan or thioether liquid at the bottom of the tower. The tower bottom buffer tank 400 and the bottom of the high-pressure distillation tower 200 are connected to a pipeline for ensuring the liquid level of the purified mercaptan or thioether liquid at the bottom of the high-pressure distillation tower 200. The qualified purified mercaptan or thioether at the top of the tower bottom buffer tank 400 is introduced into the crude mercaptan preheater 100, and the bottom of the tower bottom buffer tank 400 sends the unqualified mercaptan or thioether in the tower bottom buffer tank 400 to the crude mercaptan or thioether buffer tank through the tower bottom buffer tank output pump 500.

[0035] In summary:

[0036] The crude mercaptan containing mercaptan, sulfide, hydrogen sulfide, etc. sent from the front-end process enters the crude mercaptan preheater 100, and after heat exchange with the qualified purified mercaptan or sulfide overflowing from the bottom buffer tank 400, enters the middle part of the high-pressure distillation tower 200. The gas (hydrogen sulfide) generated during the distillation process is condensed by the high-pressure distillation tower top condenser 230 installed at the top of the high-pressure distillation tower 200, and then discharged from the top of the high-pressure distillation tower 200 and returned to the raw material hydrogen sulfide buffer tank. A part of the purified mercaptan ether liquid passes through the bottom of the high-pressure distillation tower and then The boiler 300 is heated to ensure the bottom temperature of the tower. A part of the purified mercaptan ether liquid enters the tower bottom buffer tank 400 by its own pressure. At the same time, qualified mercaptan or thioether after heat exchange in the crude mercaptan preheater 100 enters the subsequent distillation section. Unqualified mercaptan or thioether in the tower bottom buffer tank 400 is sent to the crude mercaptan or thioether buffer tank through the tower bottom buffer tank output pump (500) for re-distillation. The tower bottom buffer tank and the high-pressure distillation tower 200 are provided with a reflux pipe for controlling the liquid level of the high-pressure distillation tower 200.

[0037] In this embodiment, a gas phase outlet 220 is provided at the top of the high-pressure distillation tower 200, a pressure gauge 210 is installed at the upper and lower parts of the high-pressure distillation tower 200, a plurality of sets of thermometers 250 are installed along the height direction of the high-pressure distillation tower 200, a plurality of crude mercaptan inlets 240 are provided at the middle part of the high-pressure distillation tower 200, a liquid level gauge 270 for monitoring the highest liquid level and the lowest liquid level is installed at the lower part of the high-pressure distillation tower 200, and a reflux liquid inlet 260, a reboiler outlet pipeline connection port 280 and two tower bottom outlets 290 are also provided at the lower part of the high-pressure distillation tower 200, By connecting the reflux pipe to the reflux liquid inlet 260, the effect of guiding liquid into the high-pressure distillation tower 200 is achieved, and the liquid level inside the high-pressure distillation tower 200 is ensured. By connecting one of the two bottom discharge outlets 290 to the inlet of the reboiler 300 at the bottom of the high-pressure distillation tower through a conduit, and connecting the outlet of the reboiler 300 at the bottom of the high-pressure distillation tower to the reboiler outlet pipeline connection port 280 through a pipeline, the bottom temperature of the tower is ensured. At the same time, the other outlet of the two bottom discharge outlets 290 is connected to the bottom buffer tank 400 through a pipeline to ensure that a part of the purified thiol ether liquid enters the bottom buffer tank 400 through its own pressure.

[0038] In this embodiment, the pressure gauge 210 installed on the upper part of the high-pressure distillation tower 200 is interlocked with the regulating valve installed on the hydrogen sulfide recovery pipeline, the thermometer 250 installed on the top of the high-pressure distillation tower 200 is interlocked with the regulating valve on the coolant inlet and outlet pipelines of the top condenser 230 of the high-pressure distillation tower, and the thermometer 250 installed at the bottom of the high-pressure distillation tower 200 is interlocked with the regulating valve on the heat source pipeline of the reboiler 300 at the bottom of the high-pressure distillation tower. The liquid level meter 270 for monitoring the maximum liquid level is interlocked with the regulating valve of the bottom extraction pipeline to control the liquid level inside the high-pressure distillation tower 200.

[0039] In this embodiment, the temperature of the high-pressure distillation tower 200 is 10-150° C. and the pressure is 1.5-3 MpaG; the temperature of the crude mercaptan preheater 100 is 10-150° C. and the pressure is 1.5-3 MpaG.

[0040] In this embodiment, the high-pressure distillation tower 200 includes but is not limited to bulk packing and structured packing.

[0041] The second aspect of the present invention provides use of the device for separating hydrogen sulfide from mercaptan ethers according to the first aspect of the present invention in separating hydrogen sulfide from crude mercaptan.

[0042] The crude mercaptan containing mercaptan, sulfide, hydrogen sulfide, etc. sent from the front-end process enters the crude mercaptan preheater 100, and after heat exchange with the qualified purified mercaptan or sulfide overflowing from the bottom buffer tank 400, enters the middle part of the high-pressure distillation tower 200. The gas (hydrogen sulfide) generated during the distillation process is condensed by the high-pressure distillation tower top condenser 230 installed at the top of the high-pressure distillation tower 200, and then discharged from the top of the high-pressure distillation tower 200 and returned to the raw material hydrogen sulfide buffer tank. A part of the purified mercaptan ether liquid passes through the bottom of the high-pressure distillation tower and then The boiler 300 is heated to ensure the bottom temperature of the tower. A part of the purified mercaptan ether liquid enters the tower bottom buffer tank 400 by its own pressure. At the same time, qualified mercaptan or thioether after heat exchange in the crude mercaptan preheater 100 enters the subsequent distillation section. Unqualified mercaptan or thioether in the tower bottom buffer tank 400 is sent to the crude mercaptan or thioether buffer tank through the tower bottom buffer tank output pump (500) for re-distillation. The tower bottom buffer tank and the high-pressure distillation tower 200 are provided with a reflux pipe for controlling the liquid level of the high-pressure distillation tower 200.

Claims

1. A device for separating hydrogen sulfide from mercaptans or thioethers, characterized in that: The device includes: A crude mercaptan preheater (100) is used to perform heat exchange between the crude mercaptan and the qualified purified mercaptan or thioether to preheat the crude mercaptan; A high-pressure distillation tower (200) is used to distill the crude mercaptan after heat exchange, and to condense the gas generated during the distillation process through a high-pressure distillation tower top condenser (230) installed at the top of the high-pressure distillation tower (200) and then discharge it from the top of the high-pressure distillation tower (200), and to discharge the purified mercaptan or sulfide liquid at the bottom of the high-pressure distillation tower (200) into two outlets; A reboiler (300) at the bottom of the high-pressure distillation tower, used to heat the purified mercaptan or sulfide liquid at the bottom of the tower and introduce it into the interior of the high-pressure distillation tower (200); The tower bottom buffer tank (400) is used to buffer and collect the purified mercaptan or thioether liquid at the bottom of the tower. The tower bottom buffer tank (400) and the bottom of the high-pressure distillation tower (200) are connected to a pipeline for ensuring the liquid level of the purified mercaptan or thioether liquid at the bottom of the high-pressure distillation tower (200). The qualified purified mercaptan or thioether at the top of the tower bottom buffer tank (400) is introduced into the crude mercaptan preheater (100), and the bottom of the tower bottom buffer tank (400) sends the unqualified mercaptan or thioether inside the tower bottom buffer tank (400) to the crude mercaptan or thioether buffer tank through the tower bottom buffer tank output pump (500).

2. The device for separating hydrogen sulfide from mercaptans or thioethers according to claim 1, characterized in that: The top of the high-pressure distillation tower (200) is provided with a gas phase discharge outlet (220), the upper and lower parts of the high-pressure distillation tower (200) are both equipped with pressure gauges (210), the high-pressure distillation tower (200) is equipped with multiple groups of thermometers (250) along its height direction, the middle part of the high-pressure distillation tower (200) is provided with multiple crude mercaptan inlets (240), the lower part of the high-pressure distillation tower (200) is equipped with a liquid level gauge (270) for monitoring the highest liquid level and the lowest liquid level, and the lower part of the high-pressure distillation tower (200) is also provided with a reflux liquid inlet (260), a reboiler outlet pipeline connection port (280) and two tower bottom discharge outlets (290).

3. The device for separating hydrogen sulfide from mercaptans or thioethers according to claim 2, characterized in that: The pressure gauge (210) installed on the upper part of the high-pressure distillation tower (200) is interlocked with the regulating valve installed on the recovery pipeline used to extract the hydrogen sulfide, the thermometer (250) installed on the top of the high-pressure distillation tower (200) is interlocked with the regulating valve on the coolant outlet pipeline of the top condenser (230) of the high-pressure distillation tower, the thermometer (250) installed at the bottom of the high-pressure distillation tower (200) is interlocked with the regulating valve on the heat source pipeline of the reboiler (300) at the bottom of the high-pressure distillation tower, and the liquid level meter (270) for monitoring the highest liquid level is interlocked with the regulating valve of the bottom extraction pipeline.

4. The device for separating hydrogen sulfide from mercaptans or thioethers according to claim 1, characterized in that: The temperature of the high-pressure distillation tower (200) is 10-150°C, and the pressure is 1.5-3MpaG; the temperature of the crude mercaptan preheater (100) is 10-150°C, and the pressure is 1.5-3MpaG.

5. The device for separating hydrogen sulfide from mercaptans or thioethers according to claim 1, characterized in that: The high-pressure distillation tower (200) includes but is not limited to bulk packing and structured packing.

6. Use of the device for separating hydrogen sulfide from mercaptans or thioethers according to any one of claims 1 to 5 in separating hydrogen sulfide from crude mercaptans.

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