Method and system for removing, recycling and utilizing sulfur in refinery plant

Abstract

The invention belongs to the field of refinery purification, and discloses a method and a system for removing, recycling and utilizing sulfur in a refinery. The system comprises a sulfur-containing gas inlet pipeline, a purified gas outlet pipeline, a concentrated regenerated sulfur-containing gas outlet pipeline, a regenerated gas inlet pipeline, purification equipment, heating equipment, heat exchange equipment, cooling equipment and boosting equipment. According to the invention, environmental pollution caused by sulfur emission is greatly reduced, and the problem of sulfur pollution in the atmosphere is solved.

Description

Technical Field

[0001] The present invention belongs to the field of refinery purification, and more specifically, relates to a method and system for sulfur removal, recovery and utilization in a refinery. Background Art

[0002] In the existing sulfur removal technologies, sulfur that is difficult to remove by conventional methods in a refinery usually reaches the fuel gas and flare systems in various forms and is finally discharged into the atmospheric environment to cause pollution. Therefore, sulfur emission reduction in a refinery plays a crucial role in the treatment of atmospheric environmental pollution. Summary of the Invention

[0003] The object of the present invention is to address the sulfur treatment problem in the prior art and propose a method and system for sulfur removal, recovery and utilization in a refinery. The present invention greatly reduces the environmental pollution caused by sulfur emissions and solves the problem of sulfur pollution in the atmosphere.

[0004] To achieve the above object, in a first aspect of the present invention, there is provided a system for sulfur removal, recovery and utilization in a refinery, the system comprising: a sulfur-containing gas inlet pipeline, a purified gas outlet pipeline, a concentrated regenerated sulfur-containing gas outlet pipeline, a regenerated gas inlet pipeline, a purification device, a heating device, a heat exchange device, a cooling device and a boosting device;

[0005] The purification device is provided with an inlet for the gas to be purified, a purified gas outlet, a regenerated gas inlet and a regenerated gas outlet; an adsorption carrier is provided inside the purification device;

[0006] The sulfur-containing gas inlet pipeline is connected to the inlet for the gas to be purified;

[0007] The purified gas outlet pipeline is connected to the purified gas outlet;

[0008] The regenerated gas inlet pipeline is connected to the inlet of the boosting device through a first valve, and the outlet of the boosting device is divided into two paths, one path is connected to the concentrated regenerated sulfur-containing gas outlet pipeline through a second valve, and the other path is sequentially connected to the regenerated gas inlet and outlet of the heat exchange device, the heating device and the regenerated gas inlet;

[0009] The regenerated gas outlet is sequentially connected to the circulating gas inlet and outlet of the heat exchange device, the cooling device and the inlet of the boosting device.

[0010] According to the present invention, preferably, the sulfur-containing gas inlet pipeline is connected to the inlet for the gas to be purified through a third valve.

[0011] According to the present invention, preferably, the purified gas outlet pipeline is connected to the purified gas outlet through a fourth valve.

[0012] In a second aspect of the present invention, a method for sulfur removal, recovery and utilization in a refinery is provided. The method uses the described system and includes the following steps:

[0013] S1: Feed the sulfur-containing gas from the refinery into the purification device through the sulfur-containing gas inlet pipeline for physical and / or chemical adsorption to obtain a sulfur-containing adsorption carrier and purified gas; discharge the purified gas from the system through the purified gas outlet pipeline.

[0014] S2: Repeat step S1 until sulfur reaches the bearing capacity of the adsorption carrier; feed the regeneration gas into the system through the regeneration gas inlet pipeline, and after boosting pressure and heating in sequence, feed it into the purification device from the regeneration gas inlet to perform desorption and regeneration treatment on the sulfur-containing adsorption carrier, so that sulfur in the sulfur-containing adsorption carrier is separated from the adsorption carrier and enriched in the purification device to obtain a sulfur-containing mixed regeneration gas; alternatively, pass the sulfur-containing mixed regeneration gas through the regeneration gas outlet, the circulating gas inlet and outlet of the heat exchange device, the cooling device, the boosting device, the regeneration gas inlet and outlet of the heat exchange device, the heating device and the regeneration gas inlet in sequence, and then perform desorption and regeneration treatment in a circulating manner in the purification device, so that sulfur in the sulfur-containing adsorption carrier is separated from the adsorption carrier and enriched in the purification device to obtain a concentrated sulfur regeneration gas.

[0015] According to the present invention, preferably, the method further includes sending out the sulfur-containing mixed regeneration gas or the concentrated sulfur regeneration gas from the system, and the position where the system sends out the gas is set according to the needs of subsequent receiving users.

[0016] According to the present invention, preferably, use the sulfur-containing mixed regeneration gas as a raw material for producing sulfuric acid and send it out of the system through the second valve and the concentrated regeneration sulfur-containing gas outlet pipeline in sequence;

[0017] Alternatively, use the concentrated sulfur regeneration gas as a raw material for producing sulfuric acid and send it out of the system through the second valve and the concentrated regeneration sulfur-containing gas outlet pipeline in sequence.

[0018] According to the present invention, preferably, the flow rate of the sulfur-containing mixed regeneration gas sent out of the system through the second valve and the concentrated regeneration sulfur-containing gas outlet pipeline in sequence is adjusted within the range of 0-15% of the regeneration gas flow rate according to the sulfur content;

[0019] The flow rate of the concentrated sulfur regeneration gas sent out of the system through the second valve and the concentrated regeneration sulfur-containing gas outlet pipeline in sequence is adjusted within the range of 0-15% of the regeneration gas flow rate according to the sulfur content.

[0020] According to the present invention, preferably, the sulfur-containing gas from the refinery is a gas containing sulfur that is difficult to remove from the refinery, and the gas containing sulfur that is difficult to remove from the refinery is a gas obtained by treating the refinery gas by at least one of the alkanolamine method, the tannin extraction method, the potassium carbonate method, and the caustic scrubbing method.

[0021] According to the present invention, preferably, the sulfur-containing gas from the refinery is a gas to be purified with a sulfur content of 0.01 - 0.00001 (mol) Nm 3 / h, and the sulfur in the gas to be purified is at least one of H 2 S, mercaptan, thioether, and carbonyl sulfide.

[0022] According to the present invention, preferably, the purified gas discharged from the system is transported to a gas-using unit downstream of the refinery or discharged into the atmosphere.

[0023] According to the present invention, preferably, the regenerated gas is an inert gas; preferably, the regenerated gas is nitrogen.

[0024] The beneficial effects of the technical solution of the present invention are as follows:

[0025] The present invention solves the problem of sulfur that is difficult to remove by conventional methods in refineries and chemical plants, greatly reduces the environmental pollution caused by sulfur emissions, and solves the problem of sulfur pollution in the atmosphere.

[0026] The present invention adopts the adsorption method, and the sulfur removed can be regenerated by gas. In order to achieve the required regeneration effect of the adsorption carrier and save energy, cyclic regeneration can be adopted, that is, the adsorption carrier containing sulfur that is difficult to remove is circulated and concentrated with sulfur-containing mixed regenerated gas, and then the concentrated sulfur regenerated gas obtained is sent out of the system in a small flow rate as a raw material for producing sulfuric acid.

[0027] Other features and advantages of the present invention will be described in detail in the following specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] By describing the exemplary embodiments of the present invention in more detail in conjunction with the drawings, the above and other objects, features, and advantages of the present invention will become more apparent. Among them, in the exemplary embodiments of the present invention, the same reference numerals generally represent the same components.

[0029] Figure 1 FIG. 1 shows a schematic structural diagram of a system for sulfur removal, recovery, and utilization in a refinery provided in Embodiment 1 of the present invention.

[0030] The description of the reference numerals in the drawings is as follows:

[0031] A - Sulfur - containing gas inlet pipeline, B - Purified gas outlet pipeline, C - Concentrated regenerated sulfur - containing gas outlet pipeline, D - Regenerated gas inlet pipeline, E - Purification equipment, F - Heating equipment, G - Heat - exchange equipment, H - Cooling equipment, K - Pressure - boosting equipment, M - Third valve, N - Fourth valve, P - First valve, Q - Second valve

[0032] 1 - Untreated gas inlet, 2 - Purified gas outlet, 3 - Regenerated gas inlet, 4 - Regenerated gas outlet, 5.1 - Regenerated gas inlet, 5.2 - Regenerated gas outlet, 6.1 - Recirculating gas inlet, 6.2 - Recirculating gas outlet. Detailed implementation manners

[0033] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0034] Example 1

[0035] This example provides a system for sulfur removal, recovery and utilization in a refinery, as Figure 1 shown. The system includes: a sulfur - containing gas inlet pipeline A, a purified gas outlet pipeline B, a concentrated regenerated sulfur - containing gas outlet pipeline C, a regenerated gas inlet pipeline D, a purification equipment E, a heating equipment F, a heat - exchange equipment G, a cooling equipment H and a pressure - boosting equipment K;

[0036] The purification equipment E is provided with an untreated gas inlet 1, a purified gas outlet 2, a regenerated gas inlet 3 and a regenerated gas outlet 4; an adsorption carrier is arranged inside the purification equipment E;

[0037] The sulfur - containing gas inlet pipeline A is connected to the untreated gas inlet 1 through the third valve M;

[0038] The purified gas outlet pipeline B is connected to the purified gas outlet 2 through the fourth valve N;

[0039] The regenerated gas inlet pipeline D is connected to the inlet of the pressure - boosting equipment K through the first valve P. The outlet of the pressure - boosting equipment K is divided into two paths. One path is connected to the concentrated regenerated sulfur - containing gas outlet pipeline C through the second valve Q, and the other path is sequentially connected to the regenerated gas inlet and outlet of the heat - exchange equipment G, the heating equipment F and the regenerated gas inlet 3;

[0040] The regenerated gas outlet 4 is sequentially connected to the circulating gas inlet and outlet of the heat - exchange equipment G, the cooling equipment H and the inlet of the pressure - boosting equipment K.

[0041] Using the above system for the removal, recovery and utilization of refractory sulfur in a refinery includes the following steps:

[0042] S1: Feed the gas containing refractory sulfur from the refinery into the purification device E through the sulfur-containing gas inlet pipeline A for physical adsorption to obtain an adsorption carrier containing refractory sulfur and purified gas; discharge the purified gas from the system through the purified gas outlet pipeline B;

[0043] The gas containing refractory sulfur from the refinery is the gas obtained by treating the sulfur-containing gas from the refinery by the MDEA method; the inlet flow rate of the gas containing refractory sulfur from the refinery is 25000 Nm 3 / h, and the inlet flow rate of the refractory sulfur therein is 0.0007 Nm 3 / h.

[0044] S2: Repeat step S1 until the refractory sulfur reaches the bearing capacity of the adsorption carrier; feed nitrogen into the system through the regeneration gas inlet pipeline D, and after boosting pressure and heating in sequence, feed it into the purification device E from the regeneration gas inlet 3 (the pressure of the regeneration gas after boosting pressure and heating is 0 - 80 MPa, and the temperature is 150 - 350 °C), and perform desorption regeneration treatment on the adsorption carrier containing refractory sulfur, so that the refractory sulfur in the adsorption carrier containing refractory sulfur is separated from the adsorption carrier and enriched in the purification device E to obtain a sulfur-containing mixed regeneration gas;

[0045] Feed the sulfur-containing mixed regeneration gas in sequence through the regeneration gas outlet 4, the circulating gas inlet and outlet of the heat exchange device G, the cooling device H, the boosting device K, the regeneration gas inlet and outlet of the heat exchange device G, the heating device F and the regeneration gas inlet 3, and then perform desorption regeneration treatment in the purification device E cyclically, so that the refractory sulfur in the adsorption carrier containing refractory sulfur is separated from the adsorption carrier and enriched in the purification device E to obtain a concentrated sulfur regeneration gas as the raw material for producing sulfuric acid, and send it out of the system in sequence through the second valve Q and the concentrated regeneration sulfur-containing gas outlet pipeline C. The flow rate of the concentrated sulfur regeneration gas sent out of the system in sequence through the second valve Q and the concentrated regeneration sulfur-containing gas outlet pipeline C is 0 - 15% (mol) of the regeneration gas flow rate.

[0046] Using the method of this embodiment will reduce a large amount of SO 2 emissions. It can reduce SO 2 emissions by 14 tons in a year and can produce 21 tons of sulfuric acid per hour.

[0047] The above has described the embodiments of the present invention. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments.

Claims

1. A sulfur removal, recovery and utilization system in a refinery, characterized in that, the system includes: a sulfur-containing gas inlet pipeline, a purified gas outlet pipeline, a concentrated regenerated sulfur-containing gas outlet pipeline, a regenerated gas inlet pipeline, a purification device, a heating device, a heat exchange device, a cooling device and a pressure boosting device; the purification device is provided with a gas to be purified inlet, a purified gas outlet, a regenerated gas inlet and a regenerated gas outlet; an adsorption carrier is arranged in the purification device; the sulfur-containing gas inlet pipeline is connected to the gas to be purified inlet; the purified gas outlet pipeline is connected to the purified gas outlet; the regenerated gas inlet pipeline is connected to the inlet of the pressure boosting device through a first valve, and the outlet of the pressure boosting device is divided into two paths, one path is connected to the concentrated regenerated sulfur-containing gas outlet pipeline through a second valve, and the other path is sequentially connected to the regenerated gas inlet and outlet of the heat exchange device, the heating device and the regenerated gas inlet; the regenerated gas outlet is sequentially connected to the circulating gas inlet and outlet of the heat exchange device, the cooling device and the inlet of the pressure boosting device.

2. The sulfur removal, recovery and utilization system in a refinery according to claim 1, wherein, the sulfur-containing gas inlet pipeline is connected to the gas to be purified inlet through a third valve; the purified gas outlet pipeline is connected to the purified gas outlet through a fourth valve.

3. A sulfur removal, recovery and utilization method in a refinery, characterized in that, the method uses the system according to claim 1 or 2, and includes the following steps: S1: Feed the sulfur-containing gas from the refinery into the purification device through the sulfur-containing gas inlet pipeline for physical and / or chemical adsorption to obtain a sulfur-containing adsorption carrier and purified gas; discharge the purified gas from the system through the purified gas outlet pipeline; S2: Repeat step S1 until sulfur reaches the bearing capacity of the adsorption carrier; Feed the regenerated gas into the system through the regenerated gas inlet pipeline, and after boosting pressure and heating in sequence, feed it into the purification device from the regenerated gas inlet to perform desorption and regeneration treatment on the sulfur-containing adsorption carrier, so that sulfur in the sulfur-containing adsorption carrier is separated from the adsorption carrier and enriched in the purification device to obtain a sulfur-containing mixed regenerated gas; or, pass the sulfur-containing mixed regenerated gas sequentially through the regenerated gas outlet, the circulating gas inlet and outlet of the heat exchange device, the cooling device, the pressure boosting device, the regenerated gas inlet and outlet of the heat exchange device, the heating device and the regenerated gas inlet, and then perform desorption and regeneration treatment in the purification device in a circulating manner, so that sulfur in the sulfur-containing adsorption carrier is separated from the adsorption carrier and enriched in the purification device to obtain a concentrated sulfur regenerated gas.

4. The sulfur removal, recovery and utilization method in a refinery according to claim 3, wherein, the method further includes sending the sulfur-containing mixed regenerated gas or the concentrated sulfur regenerated gas out of the system, and the position where the system sends out the gas is set according to the needs of subsequent receiving users.

5. The sulfur removal, recovery and utilization method in a refinery according to claim 4, wherein, Use the sulfur-containing mixed regenerated gas as the raw material for producing sulfuric acid, and send it out of the system through the second valve and the concentrated regenerated sulfur-containing gas outlet pipeline in sequence; Alternatively, use the concentrated sulfur-containing regenerated gas as a raw material for producing sulfuric acid and send it out of the system successively through the second valve and the concentrated regenerated sulfur-containing gas outlet pipeline.

6. The method for sulfur removal, recovery and utilization in a refinery according to claim 5, wherein, the flow rate of the sulfur-containing mixed regenerated gas sent out of the system successively through the second valve and the concentrated regenerated sulfur-containing gas outlet pipeline is adjusted in the range of 0-15% of the regenerated gas flow rate according to the sulfur content; the flow rate of the concentrated sulfur-containing regenerated gas sent out of the system successively through the second valve and the concentrated regenerated sulfur-containing gas outlet pipeline is adjusted in the range of 0-15% of the regenerated gas flow rate according to the sulfur content.

7. The method for sulfur removal, recovery and utilization in a refinery according to claim 3, wherein, the sulfur-containing gas in the refinery is a gas containing difficult-to-remove sulfur from the refinery, and the gas containing difficult-to-remove sulfur from the refinery is a gas obtained by treating the gas in the refinery with at least one of the methods of amine method, tannin method, potassium carbonate method and alkali washing method.

8. The method for sulfur removal, recovery and utilization in a refinery according to claim 3, wherein, The sulfur-containing gas of the refinery is the gas to be purified with a sulfur content of 0.01 - 0.00001 (mol) Nm 3 / h, and the sulfur in the gas to be purified is at least one of H 2 S, mercaptan, thioether, and carbonyl sulfide.

9. The method for sulfur removal, recovery and utilization in a refinery according to claim 3, wherein, the purified gas discharged from the system is transported to the gas-using unit downstream of the refinery or discharged into the atmosphere.

10. The method for sulfur removal, recovery and utilization in a refinery according to claim 3, wherein, the regenerated gas is an inert gas; preferably, the regenerated gas is nitrogen.

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