Tower type natural gas desulfurization skid system

Abstract

A tower-type natural gas desulfurization skid system comprises a skid bottom plate (1) and guardrails (2) arranged on the periphery of the skid bottom plate (1), and is characterized in that raw material natural gas is connected with a gas-liquid separator (4) through a natural gas inlet pipeline (3), pre-desulfurized natural gas separated by the gas-liquid separator (4) is input into an absorption tower (5) through a pre-desulfurization pipeline (41), and the absorption tower (5) is connected with the gas-liquid separator (4). The separated desulfurization waste liquid is discharged through a desulfurization waste liquid pipeline (42); the absorption tower (5) is connected with a desulfurizing agent header pipe (9), the desulfurizing agent header pipe (9) is connected with a liquid supplementing pump (8), and the liquid supplementing pump (8) is connected with a fresh desulfurizing agent pipeline (7); and the lower part of the absorption tower (5) is connected with a circulating pump (6), the circulating pump (6) feeds one part of tower bottom desulfurization liquid generated by the absorption tower (5) into the desulfurizer header pipe (9), and the other part of natural gas enters the gas inlet pipeline (3) to be mixed with the natural gas. The desulfurization reagent can be recycled, the desulfurization efficiency is high, and the cost is low.

Description

Technical Field

[0001] The utility model relates to a natural gas purification technology, in particular to a natural gas desulfurization processing technology, specifically to a tower type natural gas desulfurization skid system. Background Art

[0002] As the cleanest and most efficient energy among primary energy sources, natural gas is developing rapidly in my country. With the development of a large number of gas fields, the utilization rate of natural gas in my country has gradually increased, and the upstream and downstream markets of natural gas have gradually expanded. However, the natural gas raw materials extracted from gas fields generally contain H2S, CO2 and organic sulfides, etc., and cannot be directly used in industrial production and residents' lives. The above acidic gases need to be purified and removed before further use. Among them, H2S will not only cause atmospheric pollution, but also cause catalyst poisoning and pipe corrosion during the use and transportation of natural gas. Therefore, the desulfurization process of natural gas is an extremely important part of the natural gas process system.

[0003] At present, the mainstream solutions for natural gas desulfurization at home and abroad mostly use various desulfurization reagents to absorb and remove hydrogen sulfide. According to the natural gas reserves and H2S concentration, it is divided into the direct injection method of spraying the desulfurization reagent directly into the pipeline, and the absorption tower method of spraying and circulating the desulfurization reagent. In the engineering application of the above process system, the following problems exist. 1. Incomplete reaction of the desulfurization reagent: Although the desulfurization reagent is recycled into the tower for reuse after one desulfurization, the desulfurization reagent will still exist in the discharged waste liquid, resulting in a waste of reagents; 2. Precipitation and clogging problem: During long-term operation, when the desulfurization reagent reacts with H2S oversaturated or the replacement is delayed, the HS produced by the hydrolysis of excess hydrogen sulfide - It is easy to react with the desulfurization products and produce precipitation in the absorption tower, thereby blocking the pipeline and pump, affecting the safe operation of the entire system. However, in the commonly used desulfurization process, it is difficult to complete the monitoring and separation of precipitation when the desulfurization liquid is repeatedly circulated; 3. The desulfurization system lacks linkage: when the natural gas processing volume fluctuates, the H2S concentration changes, or the desulfurization reagent efficiency fluctuates, it cannot be adjusted through automatic control, wasting manpower and material resources; 4. Lack of flexibility: when the sulfur-containing gas wells are dispersed, it is difficult to use a single system to complete the collection of multiple dispersed gas wells, which lacks flexibility.

[0004] Therefore, it is urgent to develop an advanced natural gas desulfurization process system to optimize the above engineering problems. Utility Model Content

[0005] Aiming at the problems existing in the existing natural gas desulfurization treatment process, such as incomplete reaction of desulfurization reagents, clogging of pipelines and pumps by precipitation in the absorption tower during long-term operation, lack of interlocking control and insufficient flexibility, the utility model designs a tower-type natural gas desulfurization skid system with high desulfurization efficiency, strong automatic control capability, low precipitation clogging rate and high flexibility.

[0006] The purpose of this utility model is achieved through the following technical solutions:

[0007] A tower natural gas desulfurization skid system, comprising a skid bottom plate 1 and a guardrail 2, wherein the guardrail 2 is arranged around the skid bottom plate 1, and is characterized in that: a gas-liquid separator 4, an absorption tower 5, a circulation pump 6 and a liquid replenishment pump 8 are installed in the guardrail 2 and on the skid bottom plate 1, the raw natural gas is connected to the gas-liquid separator 4 through a natural gas inlet pipeline 3, the pre-desulfurized natural gas separated by the gas-liquid separator 4 is input into the absorption tower 5 through a pre-desulfurization pipeline 41, and the desulfurized waste liquid separated by the gas-liquid separator 4 is discharged through a desulfurized waste liquid pipeline 42 at the bottom; the absorption tower 5 is connected to a desulfurizer input pipeline 42; A desulfurizer main pipe 9 is connected to the output end of a liquid replenishment pump 8, and an input end of the liquid replenishment pump 8 is connected to a fresh desulfurizer pipeline 7 for conveying fresh desulfurizer to obtain fresh desulfurizer; a circulating pump 6 is connected to the lower part of the absorption tower 5, and the circulating pump 6 sends a part of the bottom desulfurization liquid produced by the absorption tower 5 into the desulfurizer main pipe 9 through a desulfurizer circulation pipeline 61, and sends another part of the bottom desulfurization liquid into the natural gas inlet pipeline 3 through a pre-desulfurizer pipeline 62 to mix with the natural gas; the upper part of the absorption tower 5 is connected to a natural gas outlet pipeline 51 for discharging purified natural gas.

[0008] The natural gas outlet pipeline 51 is installed with a first analytical instrument device 11 which can detect the H2S concentration and upload the purified natural gas outlet parameters to the control center.

[0009] The desulfurization waste liquid pipeline 42 is installed with a second analytical instrument device 10 which can detect H2S concentration, desulfurization agent concentration, pH value and upload the data to the control center.

[0010] The second analytical instrument device 10 is provided with a turbidity meter to analyze the concentration of the sediment.

[0011] The first analytical instrument device 11 and the second analytical instrument device 10 are both interlockedly controlled with the circulation pump 6 and the liquid replenishing pump 8 .

[0012] The tower type natural gas desulfurization skid system can be movably assembled and applied to desulfurization system projects of natural gas fields with different flow rates and different H2S concentrations.

[0013] A certain amount of desulfurization liquid is retained at the bottom of the absorption tower 5, so that the natural gas introduced from the bottom of the absorption tower can fully react in the form of bubbling, and then react with the desulfurization liquid sprayed on the top of the tower for deep purification.

[0014] The utility model can use the desulfurization liquid at the bottom of the absorption tower which has completed desulfurization as the pre-desulfurization liquid to react with the raw natural gas, completely react the residual desulfurizer in the pre-desulfurization liquid, and then discharge it in the form of desulfurization waste liquid.

[0015] The second analytical instrument device can detect H2S concentration, desulfurizer concentration, pH value, and is equipped with sediment concentration detection devices such as turbidity meters, which can reflect the state of the desulfurization system by detecting the parameters of the desulfurization waste liquid. The second analytical instrument device can detect H2S concentration and reflect the purified natural gas outlet parameters.

[0016] The second analytical instrument device on the desulfurized waste liquid suppresses the formation of precipitates and reduces the H2S concentration by increasing the flow rates of the circulation pump and the replenishment pump when precipitates are detected or the H2S concentration exceeds a preset value; and reduces the flow rate of the pre-desulfurizer by reducing the flow rates of the circulation pump and the replenishment pump when the desulfurizer concentration exceeds a preset value, thereby improving the utilization rate of the pre-desulfurizer.

[0017] When the first analytical instrument device on the purified natural gas detects that the H2S concentration of the purified natural gas exceeds the standard, the first analytical instrument device combines the data analysis of the second analytical instrument device to complete the interlocking control by adjusting the flow rates of the liquid replenishment pump and the circulation pump.

[0018] The beneficial effects of the utility model are:

[0019] 1. Desulfurization reagents are reused and desulfurization efficiency is improved. In the original desulfurization process, the desulfurization waste liquid is discharged from the bottom of the absorption tower, and some effective desulfurization reagents are still present. The utility model sprays the desulfurization waste liquid onto the raw natural gas as a pre-desulfurization agent. Through the monitoring of the analytical instrument device, it can be confirmed that the discharged desulfurization waste liquid does not contain effective reagents, and the desulfurization agent efficiency can be increased from the original 60% to more than 95%.

[0020] 2. The reaction process is controllable to avoid precipitation. When the system desulfurization load increases, precipitation is likely to occur in the pipeline and the absorption tower, affecting the normal operation of the system. The first and second analytical instrument devices are used to monitor the precipitation content in the desulfurization waste liquid, intuitively understand the reaction conditions in the reaction system, and timely adjust the amount of fresh desulfurizer added and the circulation pump flow through chain control to avoid precipitation.

[0021] .3. The system realizes automatic control. The system monitors the H2S concentration of purified natural gas and various parameters of desulfurized waste liquid, and realizes automatic feedback adjustment of the replenishment pump and circulation pump, realizing the automatic operation of the entire system.

[0022] 4. The desulfurization system is skid-based. The system is skid-based and can be flexibly deployed between various sulfur-containing gas wells. After desulfurization is completed in a gas well, it can be moved to the next gas well to continue operations. This is particularly applicable in scenarios where there are many small gas wells and they are scattered. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the system composition structure of the utility model;

[0024] In the figure: 1—skid bottom plate, 2—guardrail, 3—natural gas inlet pipeline, 4—gas-liquid separator, 41—pre-desulfurization pipeline, 42—desulfurization waste liquid pipeline, 5—absorption tower, 51—natural gas outlet pipeline, 52—tower bottom pipeline, 6—circulation pump, 61—desulfurizer circulation pipeline, 62—pre-desulfurizer pipeline, 7—fresh desulfurizer pipeline, 8—liquid replenishment pump, 9—desulfurizer main pipe, 10—second analytical instrument device, 11—first analytical instrument device. DETAILED DESCRIPTION

[0025] The technical solution of the utility model will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0026] like Figure 1 shown.

[0027] A tower natural gas desulfurization skid system includes a skid bottom plate 1, a guardrail 2, a natural gas inlet pipeline 3, a gas-liquid separator 4, a pre-desulfurization pipeline 41, a desulfurization waste liquid pipeline 42, an absorption tower 5, a natural gas outlet pipeline 51, a tower bottom pipeline 52, a circulation pump 6, a desulfurizer circulation pipeline 61, a pre-desulfurizer pipeline 62, a fresh desulfurizer pipeline 7, a liquid replenishment pump 8, a desulfurizer main pipe 9, a second analytical instrument device 10 (which can be designed and manufactured by yourself or customized from the market), and a first analytical instrument device 11 (which can be designed and manufactured by yourself or customized from the market). The skid bottom plate 1 is surrounded by guardrails 2, and the gas-liquid separator 4, the absorption tower 5, the circulation pump 6 and the liquid replenishment pump 8 are all located on the skid bottom plate 1. The natural gas inlet pipeline 3 is connected to the gas-liquid separator 4, and the gas phase outlet of the gas-liquid separator 4 sends the pre-desulfurized natural gas to the absorption tower 5 through the pre-desulfurization pipeline 41. The liquid phase outlet of the gas-liquid separator 4 is connected to the desulfurization waste liquid pipeline 42, and the desulfurized waste liquid is discharged therefrom; the inlet of the absorption tower 5 is connected to the pre-desulfurization pipeline 41, the total desulfurizer inlet of the upper part of the absorption tower 5 is connected to the desulfurizer main pipe 9, the gas phase outlet of the absorption tower 5 is connected to the natural gas outlet pipeline 51, and the liquid phase outlet of the lower part of the absorption tower 5 is connected to the tower bottom pipeline 52. The desulfurization liquid at the bottom of the tower is divided into desulfurizer circulating liquid and pre-desulfurizer after passing through the circulation pump 6. The desulfurizer circulating liquid is mixed with the desulfurizer in the desulfurizer main pipe 9 through the desulfurizer circulating pipeline 61, and the pre-desulfurizer is mixed with the raw natural gas in the natural gas inlet pipeline 3 through the pre-desulfurizer pipeline 62 to pre-desulfurize the raw natural gas.

[0028] The fresh desulfurizer is input into the desulfurizer main pipe 9 through the fresh desulfurizer pipeline 7 via the replenishing pump 8 .

[0029] The second analytical instrument device 10 is located on the desulfurization waste liquid pipeline 42 , and the first analytical instrument device 11 is located on the natural gas outlet pipeline 51 , and is interlockedly controlled with the circulation pump 6 and the liquid replenishing pump 8 .

[0030] The process flow of the utility model is:

[0031] In the skid system, the raw natural gas is purified and discharged from the system after pre-desulfurization in the pipeline and secondary deep desulfurization in the absorption tower. The specific process is as follows: the pre-desulfurizer is transported into the natural gas inlet pipeline 3 through the pre-desulfurizer pipeline 62, the raw natural gas is mixed with the pre-desulfurizer in the natural gas inlet pipeline 3 and the pre-desulfurization reaction is completed, and the gas-liquid mixture formed enters the gas-liquid separator 4; the desulfurized waste liquid is discharged from the liquid phase outlet of the gas-liquid separator 4 and discharged from the system through the desulfurized waste liquid pipeline 42; the pre-desulfurized natural gas is discharged from the gas phase outlet of the gas-liquid separator 4 and enters the absorption tower 5 through the pre-desulfurization pipeline 41. The total desulfurizer is introduced into the upper part of the absorption tower 5 through the desulfurizer main pipe 9, and the natural gas in the tower is sprayed and desulfurized. The purified natural gas after spray desulfurization is discharged from the top of the absorption tower 5 from the skid system and enters the natural gas transmission network through the natural gas outlet pipeline 51.

[0032] The desulfurized liquid at the bottom of the tower is discharged from the bottom pipeline 52 at the bottom of the absorption tower 5, and is divided into two streams of liquid after being pressurized by the circulation pump 6. One stream of liquid enters the desulfurizer circulation pipeline 61 as the desulfurizer circulation liquid, and the fresh desulfurizer enters through the fresh desulfurizer pipeline 7, and enters the desulfurizer main pipe 9 after being pressurized by the liquid replenishment pump 8, and is mixed with the above desulfurizer circulation liquid to form a total desulfurizer that enters the absorption tower 5 for re-desulfurization; the other stream of liquid enters the pre-desulfurizer pipeline 62 as the pre-desulfurizer, and is sprayed into the natural gas intake pipeline 3 to pre-desulfurize the raw natural gas.

[0033] A second analytical instrument device 10 is provided on the desulfurized waste liquid pipeline 42 to record and upload desulfurized waste liquid data; a first analytical instrument device 11 is provided on the natural gas outlet pipeline 51 to record and upload purified natural gas data. The desulfurized waste liquid data and purified natural gas data are fed back to the control system, and interlocking regulation is completed by adjusting the liquid replenishment pump 8 and the circulation pump 6.

[0034] The skid block system of the utility model is movable and can be applied to desulfurization system engineering of natural gas fields with different flow rates and different H2S concentrations.

[0035] The skid system of the utility model uses the desulfurized liquid at the bottom of the absorption tower which has completed desulfurization as the pre-desulfurized liquid, reacts with the raw natural gas, completely reacts the residual desulfurizer in the pre-desulfurized liquid, and then discharges it in the form of desulfurized waste liquid.

[0036] The second analytical instrument device 10 of the utility model can detect H2S concentration, desulfurization agent concentration, pH value, and is equipped with a sediment concentration detection device such as a turbidity meter, and the desulfurization system status is fed back by detecting the parameters of the desulfurization waste liquid. The first analytical instrument device 11 can detect the H2S concentration in the purified natural gas, thereby feeding back the effect of the desulfurization system.

[0037] When the second analytical instrument device 10 of the utility model detects that the precipitate or H2S concentration exceeds the preset value, the control system suppresses the formation of precipitate and reduces the H2S concentration by increasing the flow rates of the circulation pump 6 and the replenishment pump 8; when the desulfurizer concentration exceeds the preset value, the control system reduces the flow rate of the pre-desulfurizer by reducing the flow rates of the circulation pump 6 and the replenishment pump 8, thereby improving the utilization rate of the pre-desulfurizer.

[0038] When the first analytical instrument device 11 of the utility model detects that the H2S concentration of the purified natural gas exceeds the standard, the control system combines the data analysis of the second analytical instrument device 10 to complete the interlocking control by adjusting the flow rates of the liquid replenishment pump 8 and the circulation pump 6.

[0039] The specific working conditions and control methods can be shown in the following table.

[0040]

[0041] The parts not involved in the present invention are the same as the prior art or can be implemented by using the prior art.

Claims

1. A tower type natural gas desulfurization skid system, comprising a skid bottom plate (1) and a guardrail (2), wherein the guardrail (2) is arranged around the skid bottom plate (1), and is characterized in that: A gas-liquid separator (4), an absorption tower (5), a circulation pump (6) and a liquid replenishing pump (8) are installed in the guardrail (2) and on the skid bottom plate (1); the raw natural gas is connected to the gas-liquid separator (4) through a natural gas inlet pipeline (3); the pre-desulfurized natural gas separated by the gas-liquid separator (4) is input into the absorption tower (5) through a pre-desulfurization pipeline (41); the desulfurized waste liquid separated by the gas-liquid separator (4) is discharged through a desulfurized waste liquid pipeline (42) at the bottom; the absorption tower (5) is connected to a desulfurizer main pipe (9) for inputting a total desulfurizer; the desulfurizer main pipe (9) is connected to the liquid replenishing pump (8) The output end of the liquid replenishing pump (8) is connected to the fresh desulfurizing agent pipeline (7) for conveying fresh desulfurizing agent to obtain fresh desulfurizing agent; the lower part of the absorption tower (5) is connected to a circulation pump (6), and the circulation pump (6) sends part of the bottom desulfurizing liquid produced by the absorption tower (5) into the desulfurizing agent main pipe (9) through the desulfurizing agent circulation pipeline (61), and sends the other part of the bottom desulfurizing liquid into the natural gas inlet pipeline (3) through the pre-desulfurizing agent pipeline (62) to be mixed with natural gas; the upper part of the absorption tower (5) is connected to a natural gas outlet pipeline (51) for discharging purified natural gas.

2. The tower type natural gas desulfurization skid system according to claim 1 is characterized in that The natural gas outlet pipeline (51) is installed with a first analytical instrument device (11) capable of detecting H2S concentration and uploading purified natural gas outlet parameters to a control center.

3. The tower type natural gas desulfurization skid system according to claim 2 is characterized in that The first analytical instrument device (11) is interlocked with the circulation pump (6) and the liquid replenishment pump (8) for control.

4. The tower type natural gas desulfurization skid system according to claim 1 is characterized in that The desulfurization waste liquid pipeline (42) is equipped with a second analytical instrument device (10) capable of detecting H2S concentration, desulfurization agent concentration, pH value and uploading data to a control center.

5. The tower type natural gas desulfurization skid system according to claim 4 is characterized in that The second analytical instrument device (10) is provided with a turbidity meter to analyze the concentration of the sediment.

6. The tower type natural gas desulfurization skid system according to claim 4 is characterized in that The second analytical instrument device (10) is interlocked with the circulation pump (6) and the liquid replenishment pump (8) for control.

7. The tower type natural gas desulfurization skid system according to claim 1 is characterized in that The tower type natural gas desulfurization skid system can be movably assembled and applied to desulfurization system projects of natural gas fields with different flow rates and different H2S concentrations.

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