KR20190125641A - Meg regeneration apparatus - Google Patents

Abstract

Disclosed by the present invention is an MEG regenerator. According to an embodiment of the present invention, the MEG regenerator includes: a salt removal unit which includes a flash separator of removing salt by receiving rich MEG from a pretreatment unit, a first condenser of receiving gas components of the upper part of the flash separator and condensing the same, and a first drum of separating products condensed by the first condenser into gas and liquid; a regeneration unit which includes a distillation tower of receiving the liquid component separated by the first drum, removing water from the mixture of MEG and water contained in the liquid component, and producing lean MEG, a second condenser of receiving and condensing gaseous components including water evaporated from the distillation tower, and a second drum of separating the condensed liquid component into gas and liquid; and a vacuum means which takes in at least one gas component of the first drum and the second drum to operate at least one between the salt removal unit and the regeneration unit under a reduced pressure. The MEG generator of the present invention is able to extract MEG of high purity with little energy while reducing the loss of MEG.

Description

MEG playback device {MEG REGENERATION APPARATUS}

The present invention relates to a MEG playback apparatus.

In the production of natural gas in deep water, hydrates can be produced in pipelines due to conditions of low temperature and high pressure. When supplying natural gas through a pipeline, hydrates can damage or corrode the inside of the pipeline and, in extreme cases, blockage of the pipeline or gas field can occur. Therefore, Mono Ethylene Glycol (MEG) is injected to suppress the formation of hydrates.

MEG has a strong hydrophilic ability to absorb moisture, and after being injected to suppress the formation of hydrates, MEG absorbs moisture in the gas and is recovered from the top of the offshore plant. The recovered MEG solution (hereinafter also referred to as “rich MEG”) contains impurities such as water, high soluble salts, and low soluble salts. The rich MEG can be extracted with high concentration of MEG by removing water and salts through the MEG regeneration process.

The MEG regeneration process is a pre-treatment process that removes low-solubility salts first, then removes water, then removes solid solution salts, and the entire process of evaporating the solution at once to remove salts. It includes the full stream concept.

Specifically, some treatments consist of removing low-solubility salts and hydrocarbons from the rich MEG, followed by evaporating water in the distillation column to produce lean MEG, and then removing the high-solubility salt from lean MEG. Here, the product from the bottom of the distillation column is supplied, heated in the reboiler and returned to the distillation column to evaporate water from the rich MEG to produce lean MEG.

As mentioned above, some treatments are classified as either high salt or low solubility salts with salts to be removed. Low solubility salts are mainly divalent salts such as Ca 2+, Mg 2+, Ba 2+, and are not soluble in water. Solubility decreases with increasing temperature, causing precipitation. Solid solution salts are mainly monovalent salts such as Na + and K + and are well soluble in water, and their solubility increases with increasing temperature.

Some of these treatments are energy efficient but may result in scale deposition of salts in the device. For example, if the low-solubility salt is not sufficiently removed through the pretreatment process, a decrease in efficiency due to salt deposition may occur during evaporation of water from the rich MEG to form lean MEG.

The entire process consists of removing hydrocarbons from the rich MEG, removing the solid solution and low solubility salts by flash, and then removing the water by using the difference between the break points.

This entire process consumes a large amount of energy because all salts are removed by vaporization, and salt deposition may occur with increasing heater capacity when using the heater.

Please refer to Korea Patent Registration No. 10-1795003 (registered on November 1, 2017) as a technology related to the above.

Korea Patent Registration No. 10-1795003 (registered on November 1, 2017)

An embodiment of the present invention is to provide a MEG regeneration apparatus that can extract high-purity MEG with less energy while reducing the loss of MEG.

According to an aspect of the present invention, a flash separator for removing salt by receiving rich MEG from a pretreatment unit, a first condenser for receiving and condensing a gas component on the flash separator, and a product condensed by the first condenser A salt removing unit including a first drum for gas-liquid separation; Supplying a liquid component separated by the first drum to remove water from the mixture of water and MEG contained in the liquid component to produce a distillation column to produce lean MEG, and to supply a gas component including water evaporated in the distillation column A regeneration unit including a second condenser for receiving and condensing a second drum for gas-liquid separating the condensed gas component; And vacuum means for sucking at least one gaseous component of the first drum and the second drum so that at least one of the salt removing unit and the regeneration unit is operated under reduced pressure.

The vacuum means may include an ejector for ejecting the driving fluid introduced into the first inlet at high speed toward the outlet to suck one or more gaseous components of the first drum and the second drum toward the second inlet.

The vacuum means may include a vacuum pump connected to a gas treatment line for discharging one or more gas components of the first drum and the second drum, respectively.

When the salt removing unit is operated under reduced pressure, and the regenerative unit is operated under normal pressure, the vacuum means is connected to the first drum through a first gas treatment line for discharging gas components of the first drum, and the gas of the flash separator The compressor may further include a compressor that receives a portion of the components and compresses the components.

The salt removing unit receives a product of the lower portion of the flash separator and heats it to return to the flash separator, a gas-liquid separator that receives a portion of the product of the lower portion of the flash separator and gas-liquid separator, and is supplied from the gas-liquid separator. A salt separator may be further included to separate the solid salt from the liquid component.

And a first recovery line for returning the gas component separated by the gas-liquid separator to the flash separator, and a second recovery line for returning the remaining liquid components except the solid salt separated in the salt separator to the flash separator. can do.

The regeneration unit may further include a second heater which receives the product of the lower part of the distillation column and heats it to return to the distillation column.

MEG playback apparatus according to an embodiment of the present invention can improve the efficiency of the overall operation.

In addition, it is possible to extract high-purity MEG with little energy while reducing the loss of MEG.

In addition, salt deposition may be prevented through at least one of a salt removing unit and a regeneration unit under reduced pressure.

In addition, the capacity of at least one heater of the salt removing unit and the regenerating unit can be reduced, and the separation efficiency of MEG and water can be improved.

The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 shows an MEG playback apparatus according to an embodiment of the present invention.
2 shows an MEG playback apparatus according to another embodiment of the present invention.
3 shows an MEG reproducing apparatus according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments introduced below are provided as an example to sufficiently convey the spirit of the present invention to those skilled in the art to which the present invention pertains. The present invention is not limited to the embodiments described below and may be embodied in other forms. Parts not related to the description are omitted in the drawings in order to clearly describe the present invention, in the drawings, the width, length, thickness, etc. of the components may be exaggerated for convenience. Like numbers refer to like elements throughout.

Referring to FIG. 1, the MEG regeneration apparatus 1000 according to an embodiment of the present invention removes impurities from the MEG solution recovered after being injected to suppress the generation of hydrates during natural gas production in the deep sea. High concentrations of MEG can be extracted. The MEG regeneration apparatus 1000 is operated in the ocean and may be applied to all ships and offshore structures that want to regenerate the MEG from the rich MEG recovered with natural gas after injecting the MEG into a subsea pipe. It can also be applied to land plants which require MEG regeneration processes.

The MEG reproducing apparatus 1000 includes a pretreatment unit 100, a salt removal unit 200, and a regeneration unit 300. Hereinafter, for convenience of description, the components are bundled and classified into the pretreatment unit 100, the salt removing unit 200, and the regeneration unit 300, but accordingly, the respective components may not be clearly divided. The classification may be different for convenience or due to the nature of the component.

The pretreatment unit 100 includes a hydrocarbon removal unit 110 for removing hydrocarbons contained in the rich MEG, and a gas removal unit 120 for removing gas from the rich MEG from which hydrocarbons have been removed.

Here, the rich MEG flowing into the hydrocarbon removal unit 110 may include less than about 50 wt% MEG. The hydrocarbon removal unit 110 removes the hydrocarbon mixed in the rich MEG, and the gas removal unit 120 removes the gas mixed in the rich MEG. Gas removed by the gas removal unit 120 may be discharged through the gas removal line 121, the rich MEG through the hydrocarbon removal unit 110 and the gas removal unit 120 is MEG mixed fluid supply line (L1) ) Is supplied to the flash separator 210 of the salt removal unit 200 through. The MEG mixed fluid supply line L1 connects the flash separator 210 of the hydrocarbon removal unit 110, the gas removal unit 120, and the salt removal unit 200.

The salt removing unit 200 receives a rich MEG from the pretreatment unit 100 to remove the salt, and a first pump 215 provided in the first circulation line L2 connected to the flash separator 210. The first heater 220 receives the product of the lower portion of the flash separator 210 through the heating to return to the flash separator 210 and branched from the front end of the first heater 220 of the first circulation line (L2) The solid salt is separated from the liquid component supplied from the gas-liquid separator 230 and gas-liquid separator 230 to receive a portion of the product under the flash separator 210 remaining without evaporation through the salt removal line L3, and the gas-liquid separator 230. It comprises a salt separator 240.

Here, a salt removal condenser 235 for condensing the liquid component supplied from the gas-liquid separator 230 may be provided at the front of the salt separator 240, and the liquid component condensed by the salt removal condenser 235 may be a salt separator ( 240). The salt removal line L3 is branched from the front end of the first heater 220 of the first circulation line L2 to connect the gas-liquid separator 230, the salt removal condenser 235, and the salt separator 240.

In addition, the salt removal unit 200 is provided on the top of the flash separator 210, the first condenser 250 for condensing the gas component of the upper portion of the flash separator 210 through the regeneration line (L6), and the first First supply pump for supplying the first drum 260 for gas-liquid separation of the product condensed by the condenser 250 and the liquid component separated by the first drum 260 to the distillation column 310 of the regeneration unit 300 270. Here, the regeneration line L6 connects the flash separator 210, the first condenser 250, the first drum 260, the first supply pump 270, and the distillation column 310 of the regeneration unit 300.

Below, Each component of the salt removal part 200 is demonstrated in detail.

The flash separator 210 may be operated under reduced pressure, and a vacuum is formed on the upper part by a vacuum distillation method using the principle of easily evaporating in a vacuum state, thereby evaporating water and MEG from the rich MEG supplied from the pretreatment unit 100. You can. At this time, the monovalent and divalent salts which are not evaporated gradually remain in the flash separator 210.

For the decompression operation of the flash separator 210, the first drum 260 of the salt removing unit 200 may be connected to the ejector 410 which will be described later as a vacuum means through the first gas treatment line L7.

As such, the energy consumption can be reduced by operating the flash separator 210 under reduced pressure. That is, the lower the pressure, the easier the vaporization of the liquid, and because the vaporization occurs at a lower temperature it is possible to reduce the capacity of the first heater (220).

1 to 3 of the present invention are applicable to the entire treatment method, and the amount of energy consumed in the conventional treatment method through at least one depressurization operation of the salt removing unit 200 and the regeneration unit 300. Can be significantly reduced.

The first heater 220 receives and heats the product of the lower portion of the separator 210 through the first pump 215 provided in the first circulation line L2 connected to the flash separator 210 to heat the first circulation line L2. Return to the flash separator 210 through. At this time, the capacity of the first heater 220 may be reduced by the decompression operation as described above. In addition, since the vaporization may occur in the flash separator 210 at a low temperature, the heating temperature of the first heater 220 may be lowered, and salt precipitation may be prevented through this.

That is, in the related art, when the temperature in the flash separator is high, thermal degradation of the MEG may occur, which may cause MEG loss, and salt deposition may occur in the flash separator and the first heater, resulting in a decrease in efficiency. However, embodiments of the present invention lower the temperature in the flash separator 210 to reduce the loss of MEG, prevent salt deposition in the flash separator 210 and the first heater 220, and improve efficiency and productivity. You can.

The gas-liquid separator 230 receives a portion of the product below the flash separator 210 that is not evaporated through the salt removal line L3 branched from the front end of the first heater 220 to separate the gas-liquid. In this case, the gas component separated by the gas-liquid separator 230 includes MEG and water, and the gas component may be recovered to the lower portion of the flash separator 210 through the first recovery line L4. And, the liquid component separated by the gas-liquid separator 230 contains a large amount of salt, which is supplied to the salt separator 240.

The salt separator 240 separates the solid salt from the liquid component supplied from the gas-liquid separator 230. The salt separator 240 may include a centrifugal separator for separating solid salts. The solid salt separated by the salt separator 240 includes monovalent and divalent salts, and may be discharged in a slurry state. The remaining liquid components except the solid salt separated from the salt separator 240 are recovered to the lower portion of the flash separator 210 through the second recovery line L5.

The first condenser 250 condenses the gas component evaporated from the flash separator 210 including MEG and water through the regeneration line L6.

The first drum 260 vapor-separates the product condensed by the first condenser 250.

The gas component separated by the first drum 260 is sucked into the ejector 410 through the first gas treatment line L7, and the liquid component separated by the first drum 260 is the first supply pump 270. Is supplied to the distillation column (310). The liquid component separated by the first drum 260 may include water and MEG.

The regeneration unit 300 receives a liquid component including water and MEG from the first drum 260 of the salt removing unit 200 and heats the distillation tower 310 to generate MEG from which water is removed, and the distillation tower 310. And a second heater 320 that receives and heats the product of the lower portion of the distillation column 310 through the second circulation line L8 connected thereto and returns it to the distillation column 310.

In addition, the regeneration unit 300 is provided at the top of the distillation column 310, and receives a gas component including water evaporated from the distillation column 310 through a third circulation line (L9) connected to the upper portion of the distillation column (310). A second condenser 330, a second drum 340, and a second pump 350 for condensing and returning some of them to the distillation column 310 are included. The third circulation line L9 connects the distillation column 310, the second condenser 330, the second drum 340, and the second pump 350.

Hereinafter, each component of the reproducing unit 300 will be described in detail.

The distillation column 310 heats the liquid component supplied from the first drum 260 by using a difference between break points between water and MEG to evaporate water therefrom.

The second heater 320 receives and heats the product of the lower portion of the distillation column 310 and circulates it repeatedly to the distillation column 310, through which heat is supplied to the lower product of the distillation column 310 to evaporate water.

The second condenser 330 condenses the gas component including the water evaporated from the distillation column 310.

The second drum 340 separates the gas component condensed by the second condenser 330 into gas-liquid separation. Here, the second drum 340 is connected to the ejector 410 through the second gas treatment line (L10).

The ejector 410 ejects the driving fluid flowing into the first inlet at high speed toward the outlet and sucks in the gas component of the second drum 340 through the second gas treatment line L10 toward the second inlet. At this time, the gas component of the first drum 260 described above is connected to the second inlet of the ejector 410 through the first gas treatment line L7 connected to the front end of the ejector 410 of the second gas treatment line L10. Can be introduced.

The driving fluid is supplied to the first inlet of the ejector 410 through the driving fluid supply line 401 connected to the ejector 410, and the first inlet 260 and the first inlet of the ejector 410 are provided. Gas components of the two drums 340 are sucked and mixed. The medium or high pressure driving fluid that has passed through the ejector 410 may be changed into a low pressure high temperature driving fluid. The driving fluid used in the ejector 410 may include, for example, steam or compressed air.

Through this, the salt removing unit 200 and the regeneration unit 300 may be operated under reduced pressure in a vacuum state.

In addition, through the salt removal unit 200 and the regeneration unit 300 which is operated under reduced pressure, it is possible to reduce the loss of MEG and extract high purity MEG.

In addition, salt deposition occurs in the above-described flash separator 210, the first heater 220, the distillation column 310 and the second heater 320 through the depressurization operation of the salt removal unit 200 and the regeneration unit 300 process. You can do it.

In addition, the capacity of the first heater 220 and the second heater 320 may be reduced, and the separation efficiency of MEG and water may be improved.

As another example, referring to FIG. 2, a vacuum pump 420 may be provided instead of the ejector 410 described above.

The vacuum pump 420 is provided to be connected to the second gas treatment line L10 for discharging the gas component of the second drum 340, and the gas component of the second drum 340 through the second gas treatment line L10. Inhale. In addition, the gas component of the first drum 260 may be sucked through the first gas treatment line L7 connected to the front end of the vacuum pump 420 of the second gas treatment line L10. The vacuum pump 420 may include, for example, a liquid ring vacuum pump.

As another example, referring to FIG. 3, the salt removing unit 200 may be operated under reduced pressure, and the regeneration unit 300 may be operated under normal pressure.

To this end, the first drum 260 is connected to the vacuum pump 420 as a vacuum means through the first gas treatment line (L7), the gas component of the first drum 260 is sucked into the vacuum pump 420 Can be. The gas component of the second drum 340 may be discharged and processed through the second gas treatment line L10 without being connected to a separate vacuum means. In this case, the ejector 410 may be used instead of the vacuum pump 420 as another example.

In addition, the compressor 430 is provided on the compression line 21 branched from the front end of the first condenser 250 of the regeneration line L6, and receives and compresses a part of gas components of the flash separator 210 to compress the distillation column 310. You can send

The compressor 430 may compress the gas component of the flash separator 210 according to the operating conditions of the distillation column 310.

Through this, the salt removal unit 200 is operated under reduced pressure, and the regeneration unit 300 is operated under normal pressure, thereby reducing equipment cost.

Meanwhile, the lean MEG of the distillation column 310 from which water is removed is supplied to the MEG storage tank 500 through the MEG storage line L11.

In this case, the MEG storage tank 500 may finally store MEG solution containing about 80 wt% or more of MEG, a small amount of water, and less than about 3 wt% of salt, and MEG may be additionally added if necessary.

MEG solution stored in the MEG storage tank 500 can be sent to the seabed to suppress the hydrate generation of the pipeline.

In the above, specific embodiments have been illustrated and described. However, the present invention is not limited only to the above-described embodiments, and those skilled in the art to which the present invention pertains can variously change variously without departing from the gist of the technical idea of the invention described in the claims below. Could be.

100: pretreatment unit 110: hydrocarbon removal unit
120: gas removal unit 121: gas removal line
200: salt removal unit 210: flash separator
215: first pump 220: first heater
230: gas-liquid separator 235: salt removal condenser
240: salt separator 250: first condenser
260: first drum 270: first supply pump
300: regeneration unit 310: distillation column
320: second heater 330: second condenser
340: second drum 350: second pump
401: drive fluid supply line 410: ejector
420: vacuum pump 430: compressor
500: MEG storage tank L1: MEG mixed fluid supply line
L2: first circulation line L3: salt removal line
L4: First recovery line L5: Second recovery line
L6: Regeneration Line L7: First Gas Treatment Line
L8: second circulation line L9: third circulation line
L10: second gas treatment line L11: MEG storage line
L12: compression line

Claims (7)

A flash separator for removing salt from the pretreatment unit, a first condenser for supplying and condensing a gas component on the flash separator, and a first drum for gas-liquid separation of the product condensed by the first condenser Salt removal unit comprising;
Supplying a liquid component separated by the first drum to remove water from the mixture of water and MEG contained in the liquid component to produce a distillation column to produce lean MEG, and to supply a gas component including water evaporated in the distillation column A regeneration unit including a second condenser for receiving and condensing a second drum for gas-liquid separating the condensed gas component; And
And vacuum means for sucking at least one gas component of the first drum and the second drum to operate at least one of the salt removing unit and the regeneration unit under reduced pressure. The method of claim 1,
The vacuum means includes an ejector for ejecting the driving fluid introduced into the first inlet at high speed toward the outlet to suck at least one gas component of the first drum and the second drum toward the second inlet. The method of claim 1,
And said vacuum means comprises a vacuum pump connected to a gas treatment line for discharging at least one gaseous component of said first drum and said second drum. The method of claim 1,
When the salt removal unit is operated under reduced pressure, and the regeneration unit is operated at normal pressure,
The vacuum means is connected to the first drum through a first gas treatment line for discharging the gas component of the first drum,
MEG regeneration device further comprises a compressor for receiving a portion of the gas components of the flash separator to compress and send to the distillation column. The method of claim 1,
The salt removing unit and the first heater to receive and heat the product of the lower portion of the flash separator to return to the flash separator;
A gas-liquid separator for receiving a portion of the product under the flash separator and separating the gas-liquid;
And a salt separator for separating solid salts from the liquid component supplied from the gas-liquid separator. The method of claim 5,
A first recovery line for returning the gas component separated by the gas-liquid separator to the flash separator;
And a second recovery line for returning the remaining liquid component except the solid salt separated from the salt separator to the flash separator. The method of claim 1,
The regeneration unit further comprises a second heater for receiving and heating the product of the lower part of the distillation column to return to the distillation column.

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