Liquefied gas desulfurization tower and foaming online elimination method based on pulse method thereof

Abstract

The application provides a liquefied gas desulfurization tower and a foaming online elimination method based on a pulse method, comprising the following steps: changing the liquefied gas to other devices; erecting a temporary filter at a liquid level regulating valve at the bottom of the desulfurization tower; periodically changing the amine liquid feeding amount; and using the pulse method to stimulate the impurity particles in the desulfurization tower to be washed, so that the impurity particles are filtered through the temporary filter, the garbage in the tower is removed, and the foaming phenomenon is eliminated. The application can be online cleaned, the garbage in the tower is washed out of the system by using the pulse to stimulate the garbage in the tower, the cleaning time is short, the defoaming effect is good, and the normal operation of the device is not affected.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of liquefied gas desulfurization tower, in particular to a liquefied gas desulfurization tower and a foaming online elimination method based on pulse method. BACKGROUND

[0002] Liquefied petroleum gas is a colorless volatile liquid obtained by pressurizing and cooling natural gas or petroleum in a refinery. The main components of liquefied petroleum gas obtained from the refinery are one or two of propane, propylene, butane and butene, and a small amount of pentane, pentene and trace amounts of sulfide impurities. If the liquefied petroleum gas is to be further purified, the carbon oxysulfide therein can be removed by using an alcohol amine absorption tower, and finally the excess sulfide is washed with alkali.

[0003] The alcohol amine method (such as using N-methyldiethanolamine (MDEA) for desulfurization) is the main means of liquefied gas desulfurization, which has the advantages of strong desulfurization capacity, easy analysis and regeneration, but has the disadvantage of easy foaming. Because the desulfurization tower filler is rarely cleaned after a long period of operation, there are a large amount of garbage in the filler, and impurity particles are gathered in the liquid film, which increases the stability of the bubbles, causing the amine liquid to foam, causing the desulfurization tower boundary to fluctuate, and causing the amine liquid system to be disorderly.

[0004] For the problem of amine liquid foaming, the usual treatment method is to select amine liquid with stable performance and quality to reduce the problem of foaming. When the amine liquid foams, the liquefied gas desulfurization tower needs to be cut off from the system, and a series of operations such as material withdrawal, purging, tower steaming and adding defoaming agent for defoaming are needed. This method needs to unload the filler in the tower for cleaning, which is time-consuming and labor-intensive, and the cost is high, and it affects the normal operation of the upstream device. SUMMARY

[0005] The present application provides a liquefied gas desulfurization tower and a foaming online elimination method based on pulse method to solve the above problems in the prior art.

[0006] According to one aspect of the present application, a liquefied gas desulfurization tower foaming online elimination method based on pulse method is provided, comprising:

[0007] The high-pressure hydrogenation sulfur-containing crude liquefied gas generated by the high-pressure hydrogenation device is changed to other devices, so that the high-pressure hydrogenation liquefied gas desulfurization tower is in an amine liquid circulation state;

[0008] A temporary filter is set up at the liquid level regulating valve at the bottom of the desulfurization tower;

[0009] The impurity particles in the desulfurization tower are flushed by using the pulse method, so that the impurity particles are filtered by the temporary filter, the garbage in the tower is removed, and the foaming phenomenon is eliminated.

[0010] Preferably, the step of diverting the liquefied gas to other devices is such that the high-pressure hydrogenation liquefied gas desulfurization tower is in an amine liquid circulation state, comprising:

[0011] opening the valve between the high-pressure hydrogenation device and other devices, closing the valve between the high-pressure hydrogenation device and the high-pressure hydrogenation liquefied gas desulfurization tower, and flowing the high-pressure hydrogenation crude liquefied gas produced by the high-pressure hydrogenation device to the other devices, so that the high-pressure hydrogenation liquefied gas desulfurization tower is in an amine liquid circulation state.

[0012] Preferably, the step of using the pulse method to scour the impurity particles in the desulfurization tower comprises:

[0013] periodically changing the amine liquid feed amount to generate a pulse force, and generating a high-pressure amine liquid flow at the pressure of the pulse force to impact the tower packing, form a shock wave, and scour and strip the impurity particles and deposits in the tower to be discharged out of the tower with the amine liquid flow.

[0014] Preferably, the step of periodically changing the amine liquid feed amount, wherein:

[0015] the period is 2-3 hours;

[0016] the peak of the amine liquid feed amount is 65-75 t / h;

[0017] the trough of the amine liquid feed amount is 50-60 t / h.

[0018] Preferably, the scouring time is 24 hours.

[0019] Preferably, the temporary filter is a basket filter.

[0020] Preferably, the filter screen of the temporary filter is a 200-mesh filter screen.

[0021] Preferably, the method further comprises:

[0022] cleaning the filter and discharging the poor-quality amine liquid at the bottom of the desulfurization tower and the amine liquid buffer tank blowdown pipeline to storage while cleaning the filter.

[0023] According to another aspect of the present application, a liquefied gas desulfurization tower is provided, comprising a desulfurization tower body and a temporary filter installed at the liquid level regulating valve at the bottom of the desulfurization tower body, and the liquefied gas desulfurization tower uses the foaming online elimination method described in any one of the preceding embodiments to eliminate foaming.

[0024] Compared with the prior art, the present application has at least one of the following beneficial effects:

[0025] The liquefied gas desulfurization tower and the foaming online elimination method based on the pulse method can be cleaned online, the pulse is used to stimulate the garbage in the tower, the garbage in the tower is flushed out of the system, the cleaning time is short, the defoaming effect is good, and the normal operation of the device is not affected. BRIEF DESCRIPTION OF DRAWINGS

[0026] Other features, objects, and advantages of the application will become more apparent from the following detailed description of non-limiting embodiments, when read in conjunction with the accompanying drawings:

[0027] Figure 1 The working flow chart of the liquefied gas desulfurization tower foaming online elimination method based on the pulse method in an embodiment of the application.

[0028] Figure 2 The liquefied gas desulfurization working structure schematic diagram.

[0029] Figure 3 The working structure schematic diagram of the liquefied gas desulfurization tower foaming online elimination method based on the pulse method in a preferred embodiment of the application.

[0030] Figure 4 The amine liquid quality comparison chart of the liquefied gas desulfurization tower foaming online elimination method based on the pulse method in a preferred embodiment of the application. DETAILED DESCRIPTION

[0031] The embodiments of the application are described in detail below: The embodiments are implemented on the premise of the technical solutions of the application, and detailed implementation modes and specific operation processes are given. It should be noted that, for those skilled in the art, without departing from the concept of the application, a number of modifications and improvements can be made, which are all within the protection scope of the application.

[0032] Figure 1 The working flow chart of the liquefied gas desulfurization tower foaming online elimination method based on the pulse method in an embodiment of the application.

[0033] As Figure 1 shown, the liquefied gas desulfurization tower foaming online elimination method based on the pulse method provided by the embodiment can include the following steps:

[0034] S100, to ensure that the liquefied gas quality is qualified and does not affect the operation of the downstream device, the liquefied gas is changed to other devices, so that the high-pressure hydrogenation liquefied gas desulfurization tower is in an amine liquid circulation state;

[0035] S200, a temporary filter is set at the liquid level regulating valve at the bottom of the desulfurization tower;

[0036] S300, stimulating the impurity particles in the desulfurization tower by pulse method to make the impurity particles filtered by the temporary filter, removing the garbage in the tower, and eliminating the foaming phenomenon.

[0037] In S100 of this embodiment, as a preferred embodiment, changing the liquefied gas to other devices, so that the high-pressure hydrogenation liquefied gas desulfurization tower is in the amine liquid circulation state, can include the following steps:

[0038] Opening the valve (such as valve 2, valve 3, valve 4 in Figure 2 and Figure 3 ) of the high-pressure hydrogenation device to other devices, closing the valve (such as valve 1 in Figure 2 and Figure 3 ) of the high-pressure hydrogenation device to the high-pressure hydrogenation liquefied gas desulfurization tower. The liquefied gas produced by the high-pressure hydrogenation device is backflowed to other devices, so that the high-pressure hydrogenation liquefied gas desulfurization tower is in the amine liquid circulation state.

[0039] In S30 of this embodiment, as a preferred embodiment, stimulating the impurity particles in the desulfurization tower by pulse method, can include the following steps:

[0040] Periodically changing the amine liquid feed amount to generate a pulse force, generating a high-pressure amine liquid flow with the strong pressure of the pulse force, rapidly impacting the tower filler to form a huge shock wave, and stripping the impurity particles and deposits in the tower, and then rapidly discharging them outside the tower with the amine liquid flow.

[0041] Further, as a preferred embodiment, in the periodically changing the amine liquid feed amount:

[0042] The period is 2-3 hours;

[0043] The peak of the amine liquid feed amount is 65-75 t / h;

[0044] The trough of the amine liquid feed amount is 50-60 t / h.

[0045] In a specific application example, the amine liquid feed amount is periodically changed, wherein:

[0046] The period can be 2 hours;

[0047] The peak of the amine liquid feed amount can be 75 t / h;

[0048] The trough of the amine liquid feed amount can be 55 t / h.

[0049] In a specific application example, the flushing time can be 24 hours.

[0050] In a specific application example, the temporary filter is a basket filter.

[0051] In one specific application example, the temporary filter uses a 200-mesh filter screen.

[0052] In this embodiment, as a preferred embodiment, the following steps are also included:

[0053] S400 causes amine liquid contamination and the formation of inferior amine liquid by discharging impurity particles and accumulated matter from the tower. Therefore, the filter is cleaned, and the inferior amine liquid is discharged and stored from the bottom of the desulfurization tower and the sewage pipe of the amine liquid buffer tank while the filter is being cleaned.

[0054] The technical solutions provided by the above embodiments of the present invention are further described in detail below.

[0055] Figure 2 This is a schematic diagram of the desulfurization working structure for liquefied petroleum gas.

[0056] like Figure 2 As shown, under normal process conditions, the sulfur-containing crude liquefied gas generated by the high-pressure hydrogenation unit is combined with the liquefied gas generated by other desulfurization units and flows from bottom to top through the desulfurization tower. The lean amine liquid comes into countercurrent contact with the liquefied gas from top to bottom to absorb the hydrogen sulfide in the liquefied gas. The hydrogen-rich amine liquid that has absorbed the hydrogen sulfide enters the flash tank after heat exchange and finally enters the regeneration tower for analysis and regeneration.

[0057] The foaming is caused by accumulated impurity particles inside the desulfurization tower, therefore online cleaning of the desulfurization tower is necessary. A temporary filter can be added at the liquid level regulating valve at the bottom of the desulfurization tower, such as... Figure 3 As shown.

[0058] A temporary filter is added at the liquid level regulating valve at the bottom of the desulfurization tower. The crude liquefied gas from the desulfurization process is diverted to other devices. The feed rate of amine liquid is changed periodically. The cycle can be 2 hours, with a peak flow rate of 75t / h and a trough flow rate of 55t / h. The impurity particles in the desulfurization tower are stimulated and flushed using a pulse method to filter them out of the system. The newly added temporary filter at the bottom of the tower can effectively remove the waste inside the tower and eliminate foaming phenomena online.

[0059] To prevent impurities and waste from circulating within the system, while cleaning the filter, substandard amine solution was discharged into plastic containers at the bottom of the desulfurization tower and the drain pipe of the amine buffer tank. After 24 hours of pulse cleaning, the waste inside the tower was gradually removed, and the quality of the amine solution gradually recovered. Before-and-after comparison images are shown below. Figure 4 As shown.

[0060] An embodiment of the present invention also provides a liquefied gas desulfurization tower, including a desulfurization tower body and a temporary filter installed at the liquid level regulating valve at the bottom of the desulfurization tower body. The liquefied gas desulfurization tower uses the foaming online elimination method described in any one of the above embodiments of the present invention to eliminate the foaming phenomenon.

[0061] The liquefied gas desulfurization tower and the foaming online elimination method based on the pulse method provided by the above-mentioned embodiments of the present application can effectively remove the garbage in the tower and eliminate the foaming phenomenon by temporarily setting a filter at the tower bottom regulating valve, periodically changing the amine liquid feed amount, and using the pulse method to stimulate the impurity particles in the desulfurization tower.

[0062] The above-mentioned matters not covered in the embodiments of the present application are all the known technologies in the art.

[0063] The specific embodiments of the present application are described above. It should be understood that the present application is not limited to the specific embodiments described above, and various modifications or changes can be made by those skilled in the art within the scope of the claims, which does not affect the essential content of the present application.

Claims

1. A method for on-line elimination of foaming in a liquefied gas desulfurization column based on the pulse method, characterized in that, The method comprises the following steps: The high-pressure hydrogenation sulfur-containing crude liquefied gas generated by the high-pressure hydrogenation device is diverted to other devices, so that the high-pressure hydrogenation liquefied gas desulfurization tower is in an amine liquid circulation state; A temporary filter is arranged at the liquid level regulating valve at the bottom of the desulfurization tower; Impurity particles in the desulfurization tower are flushed by using a pulse method, so that the impurity particles are filtered by the temporary filter, the garbage in the tower is removed, and the foaming phenomenon is eliminated; The method for eliminating foaming phenomenon in the high-pressure hydrogenation liquefied gas desulfurization tower in an on-line state comprises the following steps: The valve between the high-pressure hydrogenation device and other devices is opened, the valve between the high-pressure hydrogenation device and the high-pressure hydrogenation liquefied gas desulfurization tower is closed, the high-pressure hydrogenation sulfur-containing crude liquefied gas generated by the high-pressure hydrogenation device is flowed back to the other devices, so that the high-pressure hydrogenation liquefied gas desulfurization tower is in an amine liquid circulation state. The impurity particles in the desulfurization tower are flushed by using a pulse method, which comprises the following steps:

2. The on-line elimination method of the foaming of the LPG desulfurization tower based on the pulse method according to claim 1, characterized in that, The amine liquid feed amount is periodically changed to generate a pulse force, and a high-pressure amine liquid flow is generated at the pressure of the pulse force to impact the tower filler, form a shock wave, and flush and strip the impurity particles and deposits in the tower, and then the amine liquid flow is discharged out of the tower. The amine liquid feed amount is periodically changed, wherein:

3. The on-line elimination method of the foaming of the LPG desulfurization tower based on the pulse method according to claim 2, characterized in that, The period is 2-3 hours; The peak of the amine liquid feed amount is 65-75 t / h; The trough of the amine liquid feed amount is 50-60 t / h. The flushing time is 24 hours.

4. The on-line elimination method of the foaming of the LPG desulfurization tower based on the pulse method according to claim 2, characterized in that, The temporary filter is a basket filter; and / or 5. The on-line elimination method of the foaming of the LPG desulfurization tower based on the pulse method according to claim 1, characterized in that, The filter screen of the temporary filter is a 200-mesh filter screen. The method further comprises the following steps:

6. The on-line elimination of foaming in a liquefied gas desulfurization column based on the pulse method according to any one of claims 1 to 5, characterized in that, The filter is cleaned, and the poor amine liquid at the bottom of the desulfurization tower and the amine liquid buffer tank blowdown pipeline is discharged and stored while the filter is cleaned. The method comprises the following steps:

7. A liquefied gas desulfurization column characterized by comprising: The desulfurization tower body and the temporary filter arranged at the liquid level regulating valve at the bottom of the desulfurization tower body are provided, and the liquefied gas desulfurization tower adopts the foaming on-line elimination method according to any one of claims 1-6 to eliminate the foaming phenomenon.

Images