A process and apparatus for condensate separation

Abstract

The present application belongs to the technical field of petroleum chemical industry, and discloses a condensate oil separation process and device. The core of the condensate oil separation process is to improve the 'light and heavy gradual separation' process into a 'light, medium and heavy simultaneous separation' new process, and to open the side line production in the primary distillation column and the fractionating column of the condensate oil separation device. Part of the intermediate components are separated in advance, so that the back mixing of the intermediate component light naphtha in the primary distillation column and the back mixing of the intermediate component heavy naphtha in the fractionating column can be reduced, repeated rectification can be avoided, the separation difficulty of the system and the energy consumption can be effectively reduced; the C5 separation tower of the old original process is used for separating the mixed fraction of light naphtha and heavy naphtha after the pressure reduction transformation of the C5 separation tower; the heat pump technology is used in the debutanizer, the low-grade heat at the top of the tower is upgraded to serve as the reboiling heat source at the bottom of the debutanizer, part of the steam at the bottom of the tower is replaced, and the consumption of the cold utility at the top of the tower is reduced.

Description

Technical Field

[0001] This invention belongs to the field of petrochemical technology, specifically relating to a condensate oil separation process and apparatus. Background Technology

[0002] Condensate refers to the liquid phase component condensed from condensate gas fields or associated natural gas in oil fields, mainly composed of C5-C6O6. + 11 Naphtha, with a distillation range of 20℃ to 260℃ and an API value greater than 50, contains 60% to 80% naphtha fraction, making it both a high-quality fuel and a valuable feedstock for catalytic reforming. The purpose of a condensate separation unit is to separate hydrotreated condensate through distillation to obtain heavy naphtha (referred to as "heavy naphtha"), light naphtha (referred to as "light naphtha"), C5 hydrocarbons, liquefied petroleum gas (LPG), dry gas, and a small amount of fuel oils with slightly higher molecular weights than the heavy naphtha components, such as gasoline and diesel fractions. The basic process is as follows: condensate first enters a primary distillation column, separating into light and heavy naphtha; then, the light naphtha is sent to a butanizer column, and the ≤C4 fraction from the top is sent to an ethane separator, where it is separated to obtain LPG and dry gas. The ≥C5 fraction from the bottom is sent to a C5 separation column, where it is separated to obtain C5 and light naphtha. The heavy naphtha from the bottom of the primary distillation tower is sent to the fractionation tower. Heavy rocks from the top are used as reforming feed, while fuel oil from the bottom and middle sections is sent to the tank farm. Gases from the top of the butane and ethane strippers, carrying ≥C3 light hydrocarbons, are sent to the light hydrocarbon absorption tower. Circulating heavy rocks are used as absorbent to absorb the ≥C3 components, producing lean gas for fuel, while the rich oil is sent back to the primary distillation tower for reprocessing. To increase flexibility, the primary distillation tower typically has a side stream (usually closed in practice), and the extracted oil is called "straight-run naphtha," which is sent to the tank farm as a product. The existing condensate oil separation process involves five towers: a primary distillation tower, a butane stripper, a ethane stripper, a C5 separation tower, and a fractionation tower. This demonstrates the complexity of the process, the large number of towers and equipment, and the high energy consumption. For example, in a 488t / h condensate oil separation unit, the reboiler of the fractionation tower consumes approximately 2t / h of standard fuel oil, the reboiler of the primary distillation tower consumes approximately 55t / h of medium-pressure steam, and the reboiler of the butane removal tower consumes approximately 40t / h of low-pressure steam, totaling 95t / h. Therefore, developing low-energy-consumption processes is essential. Summary of the Invention

[0003] In view of the high energy consumption of current condensate oil separation processes, the present invention is conceived as follows:

[0004] 1) Adjust the process of the primary distillation column. This includes opening the side stream, extracting pumice, and converting the top pumice from pumice to C5, thereby significantly reducing the reboiling energy consumption of the primary distillation column and reducing the processing volume of the butane removal column, which in turn reduces its low-pressure steam consumption, and correspondingly shuts down the C5 separation column.

[0005] (ii) Adjusting the fractionation tower process. This includes opening the fractionation tower side stream, extracting heavy naphtha, and sending the top distillate to the previously shut-down C5 separator, while the bottom product, fuel oil, is collected. After depressurization, the C5 separator separates light naphtha and heavy naphtha. The light naphtha product exits the unit from the top, while the bottom heavy naphtha product is mixed with the heavy naphtha from the fractionation tower side stream before exiting the unit.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A process for separating condensate oil includes the following steps:

[0008] The condensate is first processed by the electro-desalting system and the hydrogenation unit, and then sent to the primary distillation tower. The side stream of the primary distillation tower and the stripping unit are started. Fuel gas, liquefied gas and C5 mixed fraction are collected from the top of the primary distillation tower, light naphtha fraction is collected from the side stream of the primary distillation tower, and a mixed fraction of light naphtha, heavy naphtha and fuel oil is collected from the bottom of the primary distillation tower.

[0009] The fuel gas, liquefied petroleum gas and C5 mixed fraction collected from the top of the primary distillation column are sent to the butane removal column. The fuel gas and liquefied petroleum gas fractions are collected from the top of the butane removal column, and the C5 product is collected from the bottom of the column.

[0010] The fuel gas and liquefied gas fractions collected from the top of the butane stripper are fed into the ethane stripper; after separation, the fuel gas product is collected from the top of the ethane stripper and the liquefied gas product is collected from the bottom of the stripper.

[0011] A mixed fraction of light naphtha, heavy naphtha, and fuel oil is collected from the bottom of the primary distillation column and sent to the fractionation column for processing. The side stream extraction and stripping unit of the fractionation column is started. A mixed fraction of light naphtha and heavy naphtha is collected from the top of the fractionation column, heavy naphtha product is collected from the side stream, and fuel oil product is collected from the bottom of the column.

[0012] The mixed fraction of light naphtha and heavy naphtha collected from the top of the fractionation tower is fed into the C5 separation tower. The light naphtha collected from the top of the C5 separation tower is mixed with the side stream collected from the primary distillation tower to obtain the product light naphtha. The heavy naphtha collected from the bottom of the C5 separation tower is mixed with the side stream collected from the fractionation tower to obtain the product heavy naphtha.

[0013] More specifically, the condensate oil separation process includes the following steps:

[0014] The condensate oil is first processed by the electro-desalting system and the hydrogenation unit before entering the primary distillation column. The overhead gas collected from the top of the primary distillation column is cooled and then subjected to gas-liquid separation. Part of the separated liquid phase (fuel gas, liquefied gas and C5 mixed fraction) is returned to the top of the primary distillation column as cold reflux, and the other part enters the butane removal column after heat exchange. The light naphtha fraction is collected from the side stream of the primary distillation column, and the mixed fraction of light naphtha, heavy naphtha and fuel oil collected from the bottom of the primary distillation column is sent to the fractionation column.

[0015] The overhead gas from the butane stripper is cooled and then subjected to gas-liquid separation. The separated liquid phase is returned to the top of the butane stripper as cold reflux, while the other liquid phase (fuel gas and liquefied petroleum gas fractions) is sent to the ethane stripper after heat exchange. C5 products are collected from the bottom of the butane stripper.

[0016] The overhead gas from the deethanizer is cooled and then subjected to gas-liquid separation. The separated liquid phase is returned to the top of the deethanizer as cold reflux, and the separated gas phase is collected as product fuel gas. Liquefied petroleum gas (LPG) is collected from the bottom of the deethanizer.

[0017] The overhead gas from the fractionation tower undergoes gas-liquid separation after heat exchange. The separated liquid phase (a mixed fraction of light naphtha and heavy naphtha) is sent to the C5 separation tower. The fuel oil product obtained from the bottom of the fractionation tower is collected after heat exchange. Heavy naphtha is obtained from the side stream of the fractionation tower.

[0018] The overhead gas from the C5 separator is cooled and then separated into gas and liquid phases. The liquid phase is returned to the top of the C5 separator as cold reflux, and the liquid phase is extracted as the product light naphtha. The heavy naphtha obtained from the bottom of the C5 separator is mixed with the heavy naphtha obtained from the side stream of the fractionation tower to obtain the product heavy naphtha, which is extracted after heat exchange.

[0019] Preferably, the condensate oil treated by the electro-desalting system and the hydrogenation unit is further heat-exchanged with the circulating stream from the top of the fractionation tower, the fuel oil obtained from the bottom of the fractionation tower, and the heavy naphtha obtained from the side stream of the fractionation tower before being sent to the primary distillation tower; the mixed fraction of light naphtha, heavy naphtha and fuel oil collected from the bottom of the primary distillation tower is first heat-exchanged with the fuel oil obtained from the bottom of the fractionation tower before being sent to the fractionation tower.

[0020] Preferably, the primary distillation column has approximately 40 to 45 theoretical plates; the feed position is located at approximately the 24th to 26th theoretical plate; and the side stream is located at approximately the 15th to 17th theoretical plate.

[0021] The reboiling heat source at the bottom of the primary distillation column is 3.5~3.7 MPa of steam;

[0022] The operating pressure of the primary distillation column is absolute pressure ~0.27 MPa;

[0023] The top gas from the primary distillation column is cooled to approximately 49°C by air and water cooling before entering the separatory tank; the liquid phase is refluxed back to the primary distillation column by a pump, and the liquid phase is pumped to the lower column.

[0024] The reflux ratio (reflux rate / distillate rate) of the primary distillation column is controlled between 4 and 5;

[0025] Adjust the air cooling and water cooling operation at the top of the column to control the operating temperature of the separator at the top of the column between 45℃ and 55℃ to ensure stable operation in summer; the operating temperature of the separator can be appropriately reduced in winter.

[0026] The side stream output of the primary distillation column is controlled at 60~80t / h to ensure that the trays maintain an appropriate liquid flow rate and prevent dry trays from appearing.

[0027] Preferably, the butane dehydrogenator has approximately 40 to 45 theoretical plates, with the feed located on approximately 14 to 17 theoretical plates;

[0028] The operating pressure at the top of the butane removal column is absolute ~1.07 MPa;

[0029] The reboiler heat source at the bottom of the butane removal column is 1.0~1.2 MPa ag of steam;

[0030] The top temperature of the butane removal column is 45~55℃;

[0031] The vaporization rate of the circulating heated material in the bottom reboiler of the butane removal tower is controlled between 15% and 25%.

[0032] The overhead gas from the butane removal tower is cooled to approximately 54°C by air and water cooling before entering the separator to ensure stable operation in summer; the operating temperature of the separator can be appropriately reduced in winter. A trace amount of gas overflows from the top of the separator and enters the fuel gas system; the liquid phase is refluxed back to the tower, and a portion is pumped to the ethane removal tower.

[0033] Preferably, fuel oil is used as the reboiling heat source at the bottom of the deethaner column;

[0034] The top temperature of the ethane stripper is 45~55℃;

[0035] The ethane stripper has approximately 45 to 55 theoretical plates, with the feed located at approximately 6 to 8 plates at the top.

[0036] The operating pressure at the top of the deethaner is absolute ~1.74 MPa;

[0037] The logarithmic mean heat transfer temperature difference of the reboiler at the bottom of the ethane removal column is ≥30℃;

[0038] The liquefied gas product at the bottom of the deethaner is used to heat the feed to the deethaner to reduce the reboiling load at the bottom of the tower.

[0039] Preferably, the fractionation column has approximately 36 to 42 theoretical plates, with the feed located at approximately 20 to 24 theoretical plates and the side stream exit located at approximately 15 to 17 theoretical plates.

[0040] The bottom of the fractionation column uses a reboiler as the reboil heat source.

[0041] The top temperature of the fractionation column is 108~112℃;

[0042] The fractionation column has no reflux;

[0043] The operating pressure at the top of the fractionation column is absolute pressure ~0.16 MPa;

[0044] The side stream output of the fractionation tower is controlled at 160~200t / h to ensure that the trays maintain an appropriate liquid flow rate and prevent dry trays from appearing.

[0045] The fuel oil at the bottom of the fractionation tower is used to heat the feed to the fractionation tower in order to reduce the reboiling load at the bottom of the fractionation tower.

[0046] Preferably, the C5 separation tower has approximately 28 to 30 theoretical plates, and the feed is located on approximately 21 to 24 theoretical plates;

[0047] Because the product at the bottom of the tower changed from light naphtha to heavy naphtha, and the composition became heavier, the C5 tower was depressurized and a 1.0~1.2MPag steam was used as the heat source.

[0048] The operating pressure of the C5 separation tower is absolute pressure ~0.12MPa;

[0049] The vaporization rate of the circulating heated material in the reboiler at the bottom of the C5 separation tower is controlled between 15% and 25%.

[0050] The bottom of the C5 separation tower uses steam as a reboiling heat source;

[0051] The top temperature of the C5 separation tower is 90~95℃.

[0052] Preferably, the condensate first passes through an electro-desalting system and a hydrogenation unit to ensure that the average heat transfer temperature difference between the cold and hot streams is ≥20°C, and to maintain the heat load of the electro-desalting unit unchanged;

[0053] Condensate oil, used as feedstock, is heated from 31.4℃ to approximately 76℃ by a hot stream before entering the electric desalting unit. The total heat load is 1130*10. 4 kcal / h;

[0054] The hydrotreated condensate oil feedstock, used as the primary distillation column feed, is heated from 66°C to approximately 117.6°C by the hot stream before entering the primary distillation column. The total heat load is 1503*10. 4 kcal / h;

[0055] The fuel oil product from the bottom of the fractionation tower is directly preheated to the feed to the fractionation tower. The logarithmic average heat transfer temperature difference between the materials is ≥30℃, and the feed to the fractionation tower is preheated from 165.1℃ to 171℃.

[0056] This invention also provides another process for condensate oil separation, which modifies part of the process of the butanizer tower. The top fuel gas and liquefied gas fractions collected from the top of the butanizer tower are compressed in two stages, pressurized and heated, and then used as the reboiling heat source at the bottom of the tower, saving some steam. Other process conditions and parameters are the same as the aforementioned condensate oil separation process.

[0057] Preferably, the top fuel gas and liquefied petroleum gas fractions collected from the top of the butane dehydrogenator are pressurized from absolute pressure ~1.07 MPa to absolute pressure ~9 MPa through two-stage compression, and the temperature is raised from 77.5℃ to 185.5℃ before being used as the reboiler heat source at the bottom of the tower, saving 1.0~1.2 MPa of steam. The logarithmic average heat transfer temperature difference of the reboiler at the bottom of the butane dehydrogenator is ≥30℃.

[0058] The present invention also provides a condensate oil separation device, comprising a primary distillation column 1, a butane removal column feed heat exchanger 51, a butane removal column 12, a butane removal column top product heat exchanger 20 for liquefied petroleum gas (LPG), an ethane removal column 21, a C5 separation column 26, and a fractionation column 33; wherein, the primary distillation column 1, the butane removal column 12, and the ethane removal column 21 are connected in sequence, and the primary distillation column 1 is also connected in sequence to the fractionation column 33 and the C5 separation column 26; a butane removal column feed heat exchanger 51 is provided between the primary distillation column 1 and the butane removal column 12, and a butane removal column top product heat exchanger 20 is provided between the butane removal column 12 and the ethane removal column 21.

[0059] Preferably, the top of the primary distillation column 1 is equipped with a primary distillation column top air cooler 3, a primary distillation column top gas circulating water cooler 4, and a primary distillation column top gas-liquid separator 5. The primary distillation column top gas outlet is sequentially connected to the primary distillation column top air cooler 3, the primary distillation column top gas circulating water cooler 4, and the primary distillation column top gas-liquid separator 5. The liquid phase outlet of the primary distillation column top gas-liquid separator 5 is divided into two channels, one connected to the primary distillation column top reflux material inlet, and the other connected to the heat exchanger 51 for the top product of the butane removal column and the feed of the butane removal column. The bottom of the primary distillation column 1 is equipped with a primary distillation column bottom steam reboiler 2, and the primary distillation column 1 is also equipped with a primary distillation column side stream extraction and stripping device 8.

[0060] The top of the butane descaling tower 12 is equipped with a butane descaling tower overhead gas air cooler 13, a butane descaling tower overhead gas circulating water cooler 14, and a butane descaling tower overhead gas-liquid separator 15. The overhead gas outlet of the butane descaling tower 12 is sequentially connected to the butane descaling tower overhead gas air cooler 13, the butane descaling tower overhead gas circulating water cooler 14, and the butane descaling tower overhead gas-liquid separator 15. The liquid phase outlet of the butane descaling tower overhead gas-liquid separator 15 is divided into two channels: one is connected to the butane descaling tower overhead reflux material inlet, and the other is connected to the butane descaling tower overhead product and liquefied gas heat exchanger 20. The bottom of the butane descaling tower 12 is equipped with a butane descaling tower bottom steam reboiler 18.

[0061] The top of the deethanizer 21 is equipped with a top circulating water cooler 22 and a top gas-liquid separator 23. The top gas outlet of the deethanizer is sequentially connected to the top circulating water cooler 22 and the top gas-liquid separator 23. The bottom of the deethanizer 21 is equipped with a bottom reboiler 25, which is also connected to the heat exchanger 20 between the top product and liquefied gas of the butaneizer. The top of the fractionation column 33 is equipped with a top circulating water and electrostatic desalting device. Heat exchanger 55, primary heat exchanger 56 for feed to the distillation column, heat exchanger 57 for oil-gas and electric desalting unit at the top of the fractionation column, and gas-liquid separator 38 at the top of the fractionation column; the material outlet at the top of the fractionation column 33 is sequentially connected to the heat exchanger 57 for oil-gas and electric desalting unit at the top of the fractionation column, the gas-liquid separator 38 at the top of the fractionation column, and the material inlet at the top of the C5 separation column 26; the reflux inlet at the top of the fractionation column is connected to the heat exchanger 55 for the electric desalting unit, the primary heat exchanger 56 for feed to the distillation column, and the reflux inlet at the top of the fractionation column;

[0062] The bottom of the fractionation column 33 is equipped with a fractionation column feed heat exchanger 52, a de-ethanizer bottom reboiler heat exchanger 47, a primary distillation column feed tertiary heat exchanger 50, and a fractionation column reboiler 44; the bottom material outlet of the fractionation column 33 is sequentially connected to the fractionation column feed heat exchanger 52, the de-ethanizer bottom reboiler heat exchanger 47, and the primary distillation column feed tertiary heat exchanger 50.

[0063] The fractionation tower 33 is also equipped with a fractionation tower side stream extraction and stripping device 34, which is connected in sequence to the new primary distillation tower feed tertiary heat exchanger 53 and the butane removal tower feed heat exchanger 51.

[0064] The C5 separation tower 26 is equipped with a C5 separation tower top gas air cooler 27 and a C5 separation tower top gas-liquid separator 28. The top gas outlet of the C5 separation tower 26 is sequentially connected to the C5 separation tower top gas air cooler 27 and the C5 separation tower top gas-liquid separator 28. The liquid phase outlet of the C5 separation tower top gas-liquid separator 28 is divided into two channels, one connected to the C5 separation tower top reflux material inlet and the other to the light naphtha product outlet. The C5 separation tower 26 is equipped with a C5 separation tower bottom steam reboiler 54, and the bottom material outlet of the C5 separation tower 26 is also connected to the butane removal tower feed heat exchanger 51.

[0065] Another condensate oil separation device provided by the present invention includes a primary distillation column 1, a butane removal column feed heat exchanger 51, a butane removal column 12, a butane removal column top product heat exchanger 20 for liquefied gas, an ethane removal column 21, a C5 separation column 26, and a fractionation column 33; wherein, the primary distillation column 1, the butane removal column 12, and the ethane removal column 21 are connected in sequence, and the primary distillation column 1 is also connected in sequence to the fractionation column 33 and the C5 separation column 26; a butane removal column feed heat exchanger 51 is provided between the primary distillation column 1 and the butane removal column 12, and a butane removal column top product heat exchanger 20 is provided between the butane removal column 12 and the ethane removal column 21;

[0066] The top of the primary distillation column 1 is equipped with a primary distillation column top air cooler 3, a primary distillation column top gas circulating water cooler 4, and a primary distillation column top gas-liquid separator 5. The bottom of the primary distillation column 1 is equipped with a primary distillation column bottom steam reboiler 2. The primary distillation column 1 is also equipped with a primary distillation column side stream extraction and stripping device 8.

[0067] The top of the butane removal tower 12 is equipped with a butane removal tower overhead gas air cooler 13, a butane removal tower overhead gas circulating water cooler 14, a butane removal tower overhead gas liquid separator 15, a butane removal tower overhead gas primary compressor 58, and a butane removal tower overhead gas secondary compressor 59; the overhead gas outlet of the butane removal tower 12 is connected to the butane removal tower overhead gas primary compressor 58, the butane removal tower overhead gas secondary compressor 59, the butane removal tower bottom reboiler heat exchanger 60, and the butane removal tower overhead gas air cooler 13. The overhead gas circulating water cooler 14 and the overhead gas-liquid separator 15 of the butane desmotherer are connected in sequence. The liquid phase outlet of the overhead gas-liquid separator 15 of the butane desmotherer is divided into two channels: one is connected to the reflux material inlet of the overhead butane desmotherer, and the other is connected to the product-liquefied gas heat exchanger 20 of the overhead butane desmotherer. The bottom of the butane desmotherer is equipped with a bottom reboiler heat exchanger 60 and a bottom steam reboiler 18. The bottom reboiler heat exchanger 60 and the bottom steam reboiler 18 of the butane desmotherer are connected.

[0068] The top of the deethanizer 21 is equipped with a top circulating water cooler 22 and a top gas-liquid separator 23. The top gas outlet of the deethanizer is sequentially connected to the top circulating water cooler 22 and the top gas-liquid separator 23. The bottom of the deethanizer 21 is equipped with a bottom reboiler 25, which is also connected to the heat exchanger 20 between the top product and liquefied gas of the butaneizer. The top of the fractionation column 33 is equipped with a top circulating water and electrostatic desalting device. Heat exchanger 55, primary heat exchanger 56 for feed to the distillation column, heat exchanger 57 for oil-gas and electric desalting unit at the top of the fractionation column, and gas-liquid separator 38 at the top of the fractionation column; the material outlet at the top of the fractionation column 33 is sequentially connected to the heat exchanger 57 for oil-gas and electric desalting unit at the top of the fractionation column, the gas-liquid separator 38 at the top of the fractionation column, and the material inlet at the top of the C5 separation column 26; the reflux inlet at the top of the fractionation column is connected to the heat exchanger 55 for the electric desalting unit, the primary heat exchanger 56 for feed to the distillation column, and the reflux inlet at the top of the fractionation column;

[0069] The bottom of the fractionation column 33 is equipped with a fractionation column feed heat exchanger 52, a de-ethanizer bottom reboiler heat exchanger 47, a primary distillation column feed tertiary heat exchanger 50, and a fractionation column reboiler 44; the bottom material outlet of the fractionation column 33 is sequentially connected to the fractionation column feed heat exchanger 52, the de-ethanizer bottom reboiler heat exchanger 47, and the primary distillation column feed tertiary heat exchanger 50.

[0070] The fractionation tower 33 is also equipped with a fractionation tower side stream extraction and stripping device 34, which is connected in sequence to the new primary distillation tower feed tertiary heat exchanger 53 and the butane removal tower feed heat exchanger 51.

[0071] The C5 separation tower 26 is equipped with a C5 separation tower top gas air cooler 27 and a C5 separation tower top gas-liquid separator 28. The top gas outlet of the C5 separation tower 26 is sequentially connected to the C5 separation tower top gas air cooler 27 and the C5 separation tower top gas-liquid separator 28. The liquid phase outlet of the C5 separation tower top gas-liquid separator 28 is divided into two channels, one connected to the C5 separation tower top reflux material inlet and the other to the light naphtha product outlet. The C5 separation tower 26 is equipped with a C5 separation tower bottom steam reboiler 54, and the bottom material outlet of the C5 separation tower 26 is also connected to the butane removal tower feed heat exchanger 51.

[0072] Compared with the prior art, the present invention has the following beneficial effects:

[0073] 1. Start the side stream of the primary distillation column to improve the "light and heavy stepwise separation" process of the primary distillation column to the "light, medium and heavy simultaneous separation" process. Some light naphtha is separated first, which reduces its backmixing and repeated distillation in the primary distillation column, improves distillation efficiency and reduces separation energy consumption.

[0074] 2. Start the side stream of the fractionation tower to improve the "light and heavy stepwise separation" process of the fractionation tower to the "light, medium and heavy simultaneous separation" process. Some of the heavy naphtha is separated first, reducing its backmixing and repeated distillation in the fractionation tower and reducing separation energy consumption. At the same time, reduce the reflux ratio of the fractionation tower to perform coarse separation of light and heavy naphtha and reduce the reboiling load at the bottom of the fractionation tower.

[0075] 3. The butane removal tower adopts heat pump technology to upgrade the low-grade heat at the top of the tower and then use it for reboiling at the bottom of the butane removal tower, replacing part of the bottom steam and reducing the consumption of cold utility systems.

[0076] 4. Reuse the existing C5 separation tower and modify it by reducing the pressure to process the light and heavy naphtha fractions that were not completely separated at the top of the fractionation tower.

[0077] 5. Adjust the heat exchange process of the feed to the primary distillation tower. The feed to the primary distillation tower will exchange heat with the top circulating oil of the fractionation tower once, the fuel oil three times, and the heavy naphtha once in sequence.

[0078] 6. Adjust the heat exchange process of the fractionation tower feed, and add a step-by-step heat exchange between the fractionation tower feed and fuel oil, which can effectively reduce the load on the heating furnace and reduce the gas consumption of the reboiler.

[0079] Adjust the heat exchange process at the top of the fractionation tower, cancel the use of the top circulation of the fractionation tower as the reboiling heat source at the bottom of the C5 separation tower, add a heat exchange process between the primary circulation of the top circulation of the fractionation tower and the feed of the primary distillation tower, add a heat exchange process between the secondary circulation of the top circulation of the fractionation tower and the electric desalting unit, and add a heat exchange process between the oil and gas at the top of the fractionation tower and the electric desalting unit.

[0080] The heat exchange process of the product taken out from the top of the original fractionation tower was eliminated, and the C5 separation tower was kept as a hot feed, which effectively reduced the load at the bottom of the C5 separation tower.

[0081] 7. Adjust the heat exchange process flow of the butane removal tower feed, add a new butane removal tower feed heat exchanger to replace the heat exchangers between the butane removal tower feed and liquefied gas, the butane removal tower feed and light naphtha, and the butane removal tower feed and fuel oil, thereby reducing the investment in heat exchange equipment. Attached Figure Description

[0082] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0083] Figure 1This is a schematic diagram of the existing sequential separation process of a primary distillation tower, a butane removal tower, a de-ethane removal tower, and a C5 separation tower, as shown in the comparative example of this invention. The main equipment in the diagram is numbered as follows: 1-Primary distillation tower, 2-Primary distillation tower bottom reboiler, 3-Primary distillation tower top air cooler, 4-Primary distillation tower top gas circulating water cooler, 5-Primary distillation tower top gas-liquid separator, 6-Primary distillation tower top product and reflux pump, 7-Primary distillation tower bottom product pump, 8-Primary distillation tower side stream extraction and stripping unit, 9-De-butane removal tower feed and LPG heat exchanger, 10-De-butane removal tower feed and light naphtha heat exchanger, 11-De-butane removal tower feed and fuel oil heat exchanger, 12-De-butane tower, 13-De-butane removal tower top gas air cooler, 14-De-butane removal tower top gas circulating water cooler, 15-De-butane removal tower top gas circulating water cooler, 16-De-butane removal tower top gas and C5 separation tower. 16. Butane tower top gas-liquid separator, 17. Butane tower top reflux pump, 18. Butane tower top product pump, 19. Butane tower bottom steam reboiler, 20. Butane tower bottom product pressure reducing valve, 21. Butane tower top product and liquefied gas heat exchanger, 22. Ethane tower, 23. Butane tower top circulating water cooler, 24. Butane tower top gas-liquid separator, 25. Butane tower bottom reboiler, 26. C5 separator, 27. C5 separator top gas-air cooler, 28. C5 separator top gas-liquid separator, 29. C5 separator top product and reflux pump, 30. C5 separator bottom reboiler, 31. C5 separator bottom product pump, 32. Butane tower feed secondary heat exchanger;

[0084] Figure 2 This is a schematic diagram of a conventional fractionating tower in the comparative example of the present invention. The main equipment in the diagram is numbered as follows: 33-fractionating tower, 34-fractionating tower side stream extraction and stripping unit, 35-fractionating tower top circulating pump, 36-C5 separator bottom reboiler, 37-primary distillation tower feed secondary heat exchanger, 38-fractionating tower top gas-liquid separator, 39-fractionating tower top product pump, 40-heavy naphtha and electro-desalting unit heat exchanger, 41-primary distillation tower feed primary heat exchanger, 42-heavy naphtha air cooler, 43-heavy naphtha circulating water cooler, 44-fractionating tower reboiler, 45-fractionating tower reboiler feed pump, 46-primary distillation tower feed quinary heat exchanger, 47-de-ethane stripper bottom reboiler heat exchanger, 48-primary distillation tower feed quaternary heat exchanger, 49-de-butane stripper feed tertiary heat exchanger, 50-primary distillation tower feed tertiary heat exchanger.

[0085] Figure 3 This is a schematic diagram of the basic process flow of the primary distillation column, butane removal column, and ethane removal column in Embodiment 1 of the present invention, based on the comparative example. The diagram shows an improvement of the "light and heavy separation" process of the primary distillation column into a "simultaneous separation of light, medium, and heavy components." The main equipment numbers in the diagram are... Figure 1Consistent with the addition of a new 51-butane tower feed heat exchanger to replace the 9-butane tower feed and LPG heat exchanger, the 10-butane tower feed and light naphtha heat exchanger, and the 11-butane tower feed and fuel oil heat exchanger.

[0086] Figure 4 This is a schematic diagram of the basic process flow of the fractionation tower and C5 separation tower in Embodiment 1 of the present invention, based on the comparative example, showing the improvement of the "light and heavy separation" process of the fractionation tower into a "simultaneous separation of light, medium, and heavy" process. The main equipment numbers in the diagram are basically the same as those in the previous embodiment. Figure 2 Consistent with the above, the following new components are added: 52 - Fractionation tower feed heat exchanger; 53 - New primary distillation tower feed tertiary heat exchanger; 54 - C5 separator bottom steam reboiler; 55 - Fractionation tower top circulation and electric desalting unit heat exchanger; 56 - Primary distillation tower feed primary heat exchanger; 57 - Fractionation tower top oil and gas and electric desalting unit heat exchanger. These components replace: 46 - Primary distillation tower feed quintuple heat exchanger; 48 - Primary distillation tower feed quaternary heat exchanger; 49 - Butane removal tower feed tertiary heat exchanger; 36 - C5 separator bottom reboiler; and 37 - Primary distillation tower feed secondary heat exchanger.

[0087] Figure 5 This is a schematic diagram of the structure of the butane removal tower heat pump process added to Embodiment 2 of the present invention, based on the basic process of Embodiment 1. The main equipment numbers in the diagram are basically the same as those in Embodiment 1. Figure 3 Consistent with the addition of a first-stage compressor for the overhead gas of the 58-debutane tower, a second-stage compressor for the overhead gas of the 59-debutane tower, and a reboiler heat exchanger for the bottom of the 60-debutane tower. Detailed Implementation

[0088] The present invention will be further described in detail below through examples.

[0089] Unless otherwise specified, the connection methods of the equipment, devices, or systems in the following embodiments and comparative examples are all pipeline connections, which are conventional techniques in the art. The placement of metering and control components such as valves, flow meters, thermometers, and pressure gauges on pipelines is also conventional in the art.

[0090] The present invention provides a condensate oil separation device scheme as follows: Figure 3 and Figure 4 As shown, the system includes a primary distillation column 1, a butane removal column feed heat exchanger 51, a butane removal column 12, a butane removal column top product heat exchanger 20 for liquefied gas, an ethane removal column 21, a C5 separation column 26, and a fractionation column 33. The primary distillation column 1, butane removal column 12, and ethane removal column 21 are connected sequentially. The primary distillation column 1 is also connected sequentially to the fractionation column 33 and the C5 separation column 26. A butane removal column feed heat exchanger 51 is provided between the primary distillation column 1 and the butane removal column 12, and a butane removal column top product heat exchanger 20 is provided between the butane removal column 12 and the ethane removal column 21.

[0091] The primary distillation column 1 is equipped with a primary distillation column top air cooler 3, a primary distillation column top gas circulating water cooler 4, and a primary distillation column top gas-liquid separator 5 at the top. The primary distillation column top gas outlet is sequentially connected to the primary distillation column top air cooler 3, the primary distillation column top gas circulating water cooler 4, and the primary distillation column top gas-liquid separator 5. The liquid phase outlet of the primary distillation column top gas-liquid separator 5 is divided into two channels: one is connected to the primary distillation column top reflux material inlet, and the other is connected to the heat exchanger 51 between the top product of the butane removal column and the feed of the butane removal column. The primary distillation column 1 is equipped with a primary distillation column bottom steam reboiler 2 at the bottom. The primary distillation column 1 is also equipped with a primary distillation column side stream extraction and stripping device 8.

[0092] The primary distillation column 1 is also sequentially connected to the primary distillation column feed primary heat exchanger 56, the primary distillation column feed tertiary heat exchanger 50, and the new primary distillation column feed tertiary heat exchanger 53. The condensate oil, after being processed by the electro-desalting system and the hydrogenation unit, is also sent to the primary distillation column 1 after exchanging heat with the circulating stream from the top of the fractionation column, the fuel oil obtained from the bottom of the fractionation column, and the heavy naphtha obtained from the side stream of the fractionation column. The overhead gas collected from the top of the primary distillation column 1 is sequentially passed through the primary distillation column overhead air cooler 3 and the primary distillation column overhead circulating stream. After being cooled by water cooler 4, the product enters the gas-liquid separator 5 at the top of the primary distillation column. The separated liquid phase (fuel gas, liquefied gas and C5 mixed fraction) is pressurized by the product at the top of the primary distillation column and reflux pump 6. Part of it is returned to the top of the primary distillation column as cold reflux, and the other part is sent to the butane de-butane column 12 after heat exchange by the feed heat exchanger 51. The light naphtha fraction is collected from the side stream of the primary distillation column 1, and the mixed fraction of light naphtha, heavy naphtha and fuel oil collected from the bottom of the primary distillation column 1 is sent to the fractionation column 33.

[0093] The top of the butane descaling tower 12 is equipped with a butane descaling tower overhead gas air cooler 13, a butane descaling tower overhead gas circulating water cooler 14, and a butane descaling tower overhead gas-liquid separator 15. The overhead gas outlet of the butane descaling tower 12 is sequentially connected to the butane descaling tower overhead gas air cooler 13, the butane descaling tower overhead gas circulating water cooler 14, and the butane descaling tower overhead gas-liquid separator 15. The liquid phase outlet of the butane descaling tower overhead gas-liquid separator 15 is divided into two channels: one is connected to the butane descaling tower overhead reflux material inlet, and the other is connected to the butane descaling tower overhead product and liquefied gas heat exchanger 20. The bottom of the butane descaling tower 12 is equipped with a butane descaling tower bottom steam reboiler 18.

[0094] The overhead gas from the butane descaling tower is cooled sequentially by the overhead air cooler 13 and the overhead circulating water cooler 14 before entering the overhead gas-liquid separator 15. The separated liquid phase is pressurized by the overhead reflux pump 16 and returned to the top of the butane descaling tower as cold reflux. The other liquid phase (fuel gas and LPG fraction) is pressurized by the overhead product pump 17, then passed through the overhead product and LPG heat exchanger 20, and finally sent to the ethane descaling tower 21. C5 product is collected from the bottom of the butane descaling tower.

[0095] The top of the deethanizer 21 is equipped with a top circulating water cooler 22 and a top gas-liquid separator 23. The top gas outlet of the deethanizer is sequentially connected to the top circulating water cooler 22 and the top gas-liquid separator 23. The bottom of the deethanizer 21 is equipped with a bottom reboiler 25, which is also connected to the top product heat exchanger 20 of the butaneizer.

[0096] After being cooled by the deethanizer top circulating water cooler 22, the gas from the top of the deethanizer enters the deethanizer top gas-liquid separator 23. The separated liquid phase is pressurized by the deethanizer top reflux pump 24 and returned to the top of the deethanizer as cold reflux. The separated gas phase is collected as product fuel gas. Liquefied petroleum gas (LPG) is collected from the bottom of the deethanizer.

[0097] The top of the fractionation tower 33 is equipped with a heat exchanger 55 for the fractionation tower top circulation and electric desalting device, a primary heat exchanger 56 for the feed of the primary distillation tower, a heat exchanger 57 for the oil-gas and electric desalting device at the top of the fractionation tower, and a gas-liquid separator 38 at the top of the fractionation tower. The material outlet at the top of the fractionation tower 33 is sequentially connected to the heat exchanger 57 for the oil-gas and electric desalting device at the top of the fractionation tower, the gas-liquid separator 38 at the top of the fractionation tower, and the material inlet at the top of the C5 separation tower 26. The heat exchanger 55 for the fractionation tower top circulation and electric desalting device and the primary heat exchanger 56 for the feed of the primary distillation tower are connected to the reflux inlet at the top of the fractionation tower.

[0098] The bottom of the fractionation column 33 is equipped with a fractionation column feed heat exchanger 52, a de-ethanizer bottom reboiler heat exchanger 47, a primary distillation column feed tertiary heat exchanger 50, and a fractionation column reboiler 44; the bottom material outlet of the fractionation column 33 is sequentially connected to the fractionation column feed heat exchanger 52, the de-ethanizer bottom reboiler heat exchanger 47, and the primary distillation column feed tertiary heat exchanger 50.

[0099] The fractionation tower 33 is also equipped with a fractionation tower side stream extraction and stripping device 34, which is connected in sequence to the new primary distillation tower feed tertiary heat exchanger 53 and the butane removal tower feed heat exchanger 51.

[0100] The bottom outlet of the primary distillation column 1 is also connected to the feed heat exchanger 52 of the fractionation column. The mixed fraction of light naphtha, heavy naphtha, and fuel oil obtained from the bottom of the primary distillation column 1 is first heat-exchanged with the fuel oil obtained from the bottom of the fractionation column 33 before being sent to the fractionation column 33. The overhead gas of the fractionation column 33 enters the gas-liquid separator 38 at the top of the fractionation column after passing through the heat exchanger 57 between the overhead oil and gas and the electric desalting unit. The separated liquid phase (the mixed fraction of light naphtha and heavy naphtha) is sent to the C5 separator 26. The fuel oil product obtained from the bottom of the fractionation column is collected after heat exchange through the feed heat exchanger 52 of the fractionation column, the reboiler heat exchanger 47 at the bottom of the deethanerizer, and the tertiary heat exchanger 50 of the primary distillation column feed. Heavy naphtha is obtained from the side stream of the fractionation column.

[0101] The C5 separation tower 26 is equipped with a C5 separation tower top gas air cooler 27 and a C5 separation tower top gas-liquid separator 28. The top gas outlet of the C5 separation tower 26 is sequentially connected to the C5 separation tower top gas air cooler 27 and the C5 separation tower top gas-liquid separator 28. The liquid phase outlet of the C5 separation tower top gas-liquid separator 28 is divided into two channels, one connected to the C5 separation tower top reflux material inlet and the other to the light naphtha product outlet. The C5 separation tower 26 is equipped with a C5 separation tower bottom steam reboiler 54, and the bottom material outlet of the C5 separation tower 26 is also connected to the butane removal tower feed heat exchanger 51.

[0102] The overhead gas from the C5 separator 26 is cooled by the C5 separator overhead gas air cooler 27 and then enters the C5 separator overhead gas-liquid separator 28. The separated liquid phase is pressurized by the C5 separator overhead product and reflux pump 29, and part of it is returned to the top of the C5 separator as cold reflux, while part of it is collected as the product light naphtha. The heavy naphtha obtained from the bottom of the C5 separator is mixed with the heavy naphtha obtained from the side stream of the fractionation tower 33 to obtain the product heavy naphtha. The product heavy naphtha is collected after heat exchange in the butane removal tower feed heat exchanger 51.

[0103] This invention also provides another solution for a condensate oil separation device, in Figure 3 and Figure 4 Based on the illustrated device, the butane de-butanizer 12 is improved by employing heat pump technology. The fuel gas and liquefied petroleum gas fractions collected from the top of the butane de-butanizer undergo two-stage compression, and after pressurization and heating, are used as a reboiling heat source at the bottom of the tower, saving some steam. For example... Figure 5 As shown: The top of the butane descaling tower 12 is equipped with a butane descaling tower top gas air cooler 13, a butane descaling tower top gas circulating water cooler 14, a butane descaling tower top gas-liquid separator 15, a butane descaling tower top gas primary compressor 58, and a butane descaling tower top gas secondary compressor 59.

[0104] The top gas outlet of the butane descaling tower 12 is sequentially connected to the first-stage compressor 58 of the top gas of the butane descaling tower, the second-stage compressor 59 of the top gas of the butane descaling tower, the reboiler heat exchanger 60 at the bottom of the butane descaling tower, the air cooler 13 of the top gas of the butane descaling tower, the circulating water cooler 14 of the top gas of the butane descaling tower, and the gas-liquid separator 15 at the top of the butane descaling tower. The liquid phase outlet of the gas-liquid separator 15 at the top of the butane descaling tower is divided into two channels, one of which is connected to the reflux material inlet at the top of the butane descaling tower, and the other of which is connected to the heat exchanger 20 between the top product of the butane descaling tower and the liquefied gas.

[0105] The bottom of the butane stripper is equipped with a bottom reboiler heat exchanger 60 and a bottom steam reboiler 18; the bottom reboiler heat exchanger 60 and the bottom steam reboiler 18 are connected.

[0106] The overhead gas from the butane descaling tower is compressed sequentially by the first-stage compressor 58 and the second-stage compressor 59, and then heat-exchanged by the reboiler heat exchanger 60 at the bottom of the butane descaling tower. After being cooled by the overhead air cooler 13 and the overhead circulating water cooler 14, it enters the overhead gas-liquid separator 15. The separated liquid phase is divided into two parts. One part is pressurized by the overhead reflux pump 16 and returned to the top of the butane descaling tower as cold reflux. The other part of the liquid phase (fuel gas and liquefied petroleum gas fraction) is pressurized by the overhead product pump 17, then passed through the overhead product and liquefied petroleum gas heat exchanger 20, and finally sent to the ethane descaling tower 21. C5 product is collected from the bottom of the butane descaling tower.

[0107] Comparative Example

[0108] The comparative example is the existing "light and heavy stepwise separation" sequential separation process in the condensate unit of a certain oil refinery. The feed rate is 498.3 t / h, and the desired products are fuel gas, liquefied petroleum gas (LPG), C5 hydrocarbons, light naphtha with an Engler distillation range of 23℃~91℃, heavy naphtha with an Engler distillation range of 89℃~180℃, and fuel oil with an Engler distillation range ≥190℃. A schematic diagram of the principle process is shown below. Figure 1 and Figure 2 As shown, the details are as follows:

[0109] 1) The condensate feedstock comes from the tank farm, and after electro-desalting and hydrotreating, it is fed into the middle of the plate distillation column 1. The overhead gas of the overhead distillation column 1 is cooled sequentially by the overhead air cooler 3 and the overhead circulating water cooler 4 before entering the overhead gas-liquid separator 5. The separated liquid phase is pressurized by the overhead product and reflux pump 6, and part of it is returned to the overhead distillation column as cold reflux, while part is collected as product. The bottom liquid product is pressurized by the bottom product pump 7 and sent to the fractionation column. The reboiler 2 at the bottom of the overhead distillation column uses 3.6 MPa steam as a heat source. The side stream and stripping unit 8 of the overhead distillation column are not turned on.

[0110] 2) The mixed fraction of fuel gas, liquefied petroleum gas, C5 and light naphtha drawn from the top of the primary distillation tower is fed into the debutanizer 12 after passing through the debutanizer feed and liquefied petroleum gas heat exchanger 9, the debutanizer feed and light naphtha heat exchanger 10, and the debutanizer feed and fuel oil heat exchanger 11. The top gas of the debutanizer is cooled by the debutanizer top air cooler 13 and the debutanizer top circulating water cooler 14 in sequence, and then enters the debutanizer top gas-liquid separator 15. The separated liquid phase is pressurized by the debutanizer top reflux pump 16 and returned to the top of the debutanizer as cold reflux. The liquid phase is pressurized by the debutanizer top product pump 17 and then collected. The bottom product of the debutanizer is depressurized by the debutanizer bottom product pressure reducing valve 19 and sent to the C5 separation tower 26. The bottom steam reboiler 18 of the debutanizer uses 1.2 MPa steam as a heat source.

[0111] 3) The top product from the butane stripper is fed into the ethylene stripper 21 via the ethylene stripper top product and LPG heat exchanger 20. The ethylene stripper top gas is cooled by the ethylene stripper top circulating water cooler 22 and then enters the ethylene stripper top gas-liquid separator 23. The separated liquid phase is pressurized by the ethylene stripper top reflux pump 24 and returned to the top of the ethylene stripper as cold reflux. The separated gas phase is collected as product fuel gas. LPG product is collected from the bottom of the ethylene stripper. The ethylene stripper bottom reboiler 25 uses fuel oil as a heat source.

[0112] 4) The overhead gas from the C5 separator 26 is cooled by the C5 separator overhead gas air cooler 27 and then enters the C5 separator overhead gas-liquid separator 28. The separated liquid phase is pressurized by the C5 separator overhead product and reflux pump 29, and part of it is returned to the top of the C5 separator as cold reflux, and part of it is collected as product C5. The bottom product from the C5 separator is pressurized by the C5 separator bottom product pump 31 and sent to the butane removal tower feed secondary heat exchanger 32 to obtain the product light naphtha. The C5 separator bottom reboiler 30 uses the top circulation of the fractionation tower 33 as a heat source.

[0113] 5) The mixed fraction of heavy naphtha and fuel oil collected from the bottom of the primary distillation tower is fed into the fractionation tower 33. The overhead gas of the fractionation tower passes through the secondary heat exchanger 37 of the primary distillation tower feed and then enters the gas-liquid separator 38 at the top of the fractionation tower. The separated liquid phase is pressurized by the product pump 39 at the top of the fractionation tower and sent to the heat exchanger 40 of the heavy naphtha and electro-desalting unit and the primary heat exchanger 41 of the primary distillation tower feed. After passing through the heavy naphtha air cooler 42 and the heavy naphtha circulating water cooler 43, the heavy naphtha product is obtained. The liquid phase at the bottom of the distillation column is pressurized by the reboiler feed pump 45 and sent to the reboiler 44 of the distillation column for heating before returning to the bottom of the distillation column. Part of the liquid phase is sent as product to the fifth heat exchanger 46 of the primary distillation column feed, the reboiler heat exchanger 47 of the deethaner bottom, the fourth heat exchanger 48 of the primary distillation column feed, the third heat exchanger 49 of the debutanerizer feed, and the third heat exchanger 50 of the primary distillation column feed, finally yielding fuel oil product. The side stream extraction and stripping unit 34 at the bottom of the distillation column is not turned on.

[0114] Clearly, the comparative ratio is a process of "gradual separation of light and heavy parts".

[0115] The composition of the comparative process products is shown in Table 1.

[0116] Table 1. Composition of products from comparative process technologies

[0117]

[0118] As shown in Table 1, the product outputs are: fuel gas 0.2 t / h, liquefied petroleum gas 18.2 t / h, C5 15.3 t / h, light naphtha 130.5 t / h, heavy naphtha 245.7 t / h, and fuel oil 88.4 t / h, totaling 498.3 t / h. The C5 component content in the C5 product is 99.9% v; the distillation range of the light naphtha product is 36.7~84.4℃; the distillation range of the heavy naphtha product is 91.3~178℃; and the distillation range of the fuel oil is >193.3℃, ​​all meeting production requirements.

[0119] The main operating parameters of the five towers in the comparative process are shown in Table 2.

[0120] Table 2 Main operating parameters of the five comparative towers

[0121]

[0122] The total cooling load of the five towers in the comparison is 8500*10 4 kcal / h, total reboiling load is 7599*10 4 kcal / h. The comparative cooling load consumes 755.1 t / h of circulating water, costing 20.147 million yuan / year; the 1.2 MPa steam heating load is 2061 * 10 4 kcal / h, equivalent to 39.9t / h of 1.2MPag steam consumption, with an annual cost of 66.713 million yuan; 3.6MPag steam heating load is 2752*10 4 kcal / h, equivalent to 3.6 MPa of steam 53.7 t / h, cost is 100.526 million yuan / year; reboiler heating load is 2424*10 4 The energy consumption is calculated as kcal / h, equivalent to 1.96 t / h of fuel gas, with an annual cost of 49.705 million yuan. Based on the above results, the total energy cost for Comparative Example 1 is 237.091 million yuan per year.

[0123] Example 1

[0124] The principle flow of this invention embodiment is as follows: Figure 3 , Figure 4 As shown, the raw materials are the same as in the comparative example, both undergoing the same electro-desalting and hydrogenation processes. The main modifications involve opening the side streams of the primary distillation column and fractionation column, and modifying the C5 separator to process the light and heavy naphtha mixed fractions. This embodiment adjusts the component separation sequence based on the comparative example, changing the "light-heavy stepwise separation" process to a "light, medium, and heavy simultaneous separation" sequential separation process. Details are as follows:

[0125] 1) Condensate feedstock comes from the tank farm, and after electro-desalting and hydrogenation, it is fed into the middle of the plate distillation column 1. The side stream of the distillation column and the stripping unit 8 are started. Fuel gas, liquefied petroleum gas and C5 mixed fraction are collected from the top of the distillation column, light naphtha fraction is collected from the side stream of the distillation column, and a mixed fraction of light naphtha, heavy naphtha and fuel oil is collected from the bottom of the distillation column. The mixed heavy naphtha is directly heated to feed the butane de-butane column. A new butane de-butane column feed heat exchanger 51 is added to replace the 9-butane de-butane column feed heat exchanger with liquefied petroleum gas, the 10-butane column feed heat exchanger with light naphtha, and the 11-butane column feed heat exchanger with fuel oil.

[0126] 2) The fuel gas and liquefied gas fractions collected from the top of the butane removal tower are sent to the ethane removal tower, and the C5 product is collected from the bottom of the tower;

[0127] 3) The deethane removal tower is the same as the comparative example.

[0128] 4) The C5 separation tower is depressurized and modified into a light and heavy naphtha separation tower; light naphtha is collected from the top of the C5 separation tower and mixed with the side stream from the primary distillation tower to obtain the product light naphtha; heavy naphtha is collected from the bottom of the C5 separation tower and mixed with the side stream from the fractionation tower to obtain the product heavy naphtha; the original reboiler 30 at the bottom of the C5 separation tower is removed and replaced with a steam reboiler 54 at the bottom of the C5 separation tower; the original heat exchanger 40 between heavy naphtha and the electric desalting unit, the primary heat exchanger 41 for the feed of the primary distillation tower, the heavy naphtha air cooler 42, and the heavy naphtha circulating water cooler 43 are removed.

[0129] 5) The mixed fraction of light naphtha, heavy naphtha and fuel oil collected from the bottom of the primary distillation tower is sent to the fractionation tower 33, and the side stream extraction and stripping unit 34 of the fractionation tower is started; the mixed fraction of light naphtha and heavy naphtha collected from the top of the fractionation tower is sent to the C5 separation tower, the heavy naphtha fraction is collected from the side stream of the fractionation tower, and the fuel oil fraction is collected from the bottom of the fractionation tower.

[0130] 6) Adjust the heat exchange process. The heat required for electric desalting is provided by the top circulation of the fractionation tower and the top oil and gas. Add heat exchanger 55 between the top circulation of the fractionation tower and the electric desalting unit, and heat exchanger 57 between the top oil and gas of the fractionation tower and the electric desalting unit. Remove the reboiler 36 at the bottom of the C5 separator and the secondary heat exchanger 37 for the feed of the primary distillation tower. The following components are added: a new fractionation tower feed heat exchanger 52, a new primary distillation tower feed tertiary heat exchanger 53, and a primary distillation tower feed primary heat exchanger 56. The primary distillation tower feed quintuplet heat exchanger 46, the primary distillation tower feed quaternary heat exchanger 48, and the butane removal tower feed tertiary heat exchanger 49 are removed. The primary distillation tower feed passes through the primary distillation tower feed primary heat exchanger 56, the primary distillation tower feed tertiary heat exchanger 50, and the new primary distillation tower feed tertiary heat exchanger 53, and exchanges heat with the fractionation tower top circulation, fuel oil, and heavy naphtha in sequence before entering the primary distillation tower. The fractionation tower feed passes through the fractionation tower feed heat exchanger 52 and is preheated by fuel oil before entering the fractionation tower.

[0131] The composition of the process product in Example 1 is shown in Table 3.

[0132] Table 3 Composition of Process Products in Example 1

[0133]

[0134] Table 1 shows that the product outputs are: fuel gas 0.2 t / h, liquefied petroleum gas 18 t / h, C5 23.4 t / h, light naphtha 127.3 t / h, heavy naphtha 244 t / h, and fuel oil 85.4 t / h, totaling 498.3 t / h. The C5 component content in the C5 product is 99.9% v; the distillation range of the light naphtha product is 22.5~91.1℃; the distillation range of the heavy naphtha product is 89.5~191℃; and the distillation range of the fuel oil is >196℃, all meeting production requirements.

[0135] The main operating parameters of the five towers in Example 1 are shown in Table 4.

[0136] Table 4 Main operating parameters of the five towers in Example 1

[0137]

[0138] In Example 1, the total cooling load of the five towers is 6487*10 4 kcal / h, total reboiling load is 6972*10 4 kcal / h. Example 1: Cooling load consumption of circulating water is 576.3 t / h, costing 15.376 million yuan / year; 1.2 MPa steam heating load is 2076 * 10 4 kcal / h, equivalent to 41t / h of 1.2MPag steam consumption, costing 68.552 million yuan / year; 3.6MPag steam heating load is 2273*10 4 kcal / h, equivalent to 3.6 MPa of steam 43 t / h, cost is 80.496 million yuan / year; reboiler heating load is 2573*10 4 The energy consumption is 2.08 t / h, equivalent to 1 kcal / h of fuel gas, with an annual cost of 52.748 million yuan. Based on the above results, the total energy cost for Example 1 is 217.172 million yuan / year, a decrease of 19.919 million yuan / year compared to the comparative example, representing a reduction of 8.4%.

[0139] Example 2

[0140] This embodiment is a further improvement on Embodiment 1, adding a first-stage compressor 58 for the overhead gas of the butane removal column, a second-stage compressor 59 for the overhead gas of the butane removal column, and a reboiler heat exchanger 60 at the bottom of the butane removal column. It employs a heat pump process, and its structural schematic diagram is shown below. Figure 5As shown: (The remaining undescribed processes are the same as in Example 1, and will not be repeated here.) In this example, the overhead gas from the butane degassing tower is pressurized by the primary compressor 58 and the secondary compressor 59, and then sent to the bottom reboiler heat exchanger 60 of the butane degassing tower to exchange heat with part of the bottom reboiler circulating oil, replacing the steam consumption of the bottom reboiler 18. Thus, through heat pump technology, at the cost of some electricity, the low-temperature overhead gas from the butane degassing tower is used as the bottom reboiler heat source, effectively recovering the low-temperature heat, saving steam, and reducing the cooling load.

[0141] The product composition using this embodiment is exactly the same as that shown in Table 3.

[0142] The operating parameters of each tower in this embodiment are shown in Table 5.

[0143] Table 5 Main operating parameters of the five towers in Example 2

[0144]

[0145] In Example 2, the total cooling load of the five towers was 6287*10⁴ kcal / h, and the total reboiling load was 6972*10⁴ kcal / h. 4 kcal / h. Example 2: Cooling load consumption of circulating water is 558.5 t / h, costing 14.902 million yuan / year; 1.2 MPa steam heating load is 1876 * 10 4 kcal / h, equivalent to 37t / h of 1.2MPag steam consumption, costing 61.948 million yuan / year; 3.6MPag steam heating load is 2273*10 4 kcal / h, equivalent to 3.6 MPa of steam 43 t / h, cost is 80.496 million yuan / year; reboiler heating load is 2573*10 4 The energy consumption is 2.08 t / h, equivalent to 1162 kW, with an annual cost of 52.748 million yuan; the electricity consumption is 1162 kW, with an annual cost of 6.228 million yuan. Based on the above results, the total energy cost of Example 2 is 216.322 million yuan per year, a decrease of 20.769 million yuan per year compared to the comparative example, representing a reduction of 8.8%.

[0146] Based on the above two technical solutions, this invention improves the original sequential separation process of "light and heavy separation" as follows: It opens the side stream of the primary distillation tower to extract a portion of light naphtha, changing its function from conventional light and heavy naphtha separation to removing C5≤ components; it opens the side stream of the original fractionation tower, producing light and heavy naphtha at the top, heavy naphtha at the side stream, and fuel oil at the bottom; it transforms the original C5 separation tower into a light and heavy naphtha separation tower; and it improves the "light and heavy separation" process into a "simultaneous separation of light, medium, and heavy" process with "light and heavy separation." While ensuring the effective separation of qualified fuel gas, liquefied petroleum gas, light naphtha, heavy naphtha, and fuel oil, it significantly reduces the separation energy consumption of the condensate unit. Simultaneously, the butane removal tower uses heat pump technology, using a portion of electricity as a reboiling heat source at the bottom of the tower, effectively recovering heat from the low temperature, saving steam and reducing the cooling load.

[0147] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A process for the separation of condensate, characterized in that, Includes the following steps: The condensate is first processed by the electro-desalting system and the hydrogenation unit, and then sent to the primary distillation tower. The side stream of the primary distillation tower and the stripping unit are started. Fuel gas, liquefied gas and C5 mixed fraction are collected from the top of the primary distillation tower, light naphtha fraction is collected from the side stream of the primary distillation tower, and a mixed fraction of light naphtha, heavy naphtha and fuel oil is collected from the bottom of the primary distillation tower. The fuel gas, liquefied petroleum gas and C5 mixed fraction collected from the top of the primary distillation column are sent to the butane removal column. The fuel gas and liquefied petroleum gas fractions are collected from the top of the butane removal column, and the C5 product is collected from the bottom of the column. The fuel gas and liquefied gas fractions drawn from the top of the butane stripper are fed into the ethane stripper. After separation, fuel gas is collected from the top of the deethaner column and liquefied petroleum gas is collected from the bottom of the column; A mixed fraction of light naphtha, heavy naphtha, and fuel oil is collected from the bottom of the primary distillation column and sent to the fractionation column for processing. The side stream extraction and stripping unit of the fractionation column is started. A mixed fraction of light naphtha and heavy naphtha is collected from the top of the fractionation column, heavy naphtha product is collected from the side stream, and fuel oil product is collected from the bottom of the column. The mixed fraction of light naphtha and heavy naphtha collected from the top of the fractionation tower is fed into the C5 separation tower. The light naphtha collected from the top of the C5 separation tower is mixed with the side stream collected from the primary distillation tower to obtain the product light naphtha. The heavy naphtha collected from the bottom of the C5 separation tower is mixed with the side stream collected from the fractionation tower to obtain the product heavy naphtha.

2. The separation process according to claim 1, characterized in that, The fuel gas and liquefied gas fractions extracted from the top of the butane removal tower are subjected to two-stage compression, pressurized and heated, and then used as a reboiling heat source at the bottom of the tower.

3. The separation process according to claim 1 or 2, characterized in that, The condensate oil, after being processed by the electro-desalting system and the hydrogenation unit, is sent to the primary distillation tower after exchanging heat with the circulating stream from the top of the distillation tower, the fuel oil from the bottom of the distillation tower, and the heavy naphtha from the side stream of the distillation tower. The mixed fraction of light naphtha, heavy naphtha, and fuel oil collected from the bottom of the primary distillation tower is sent to the primary distillation tower after exchanging heat with the fuel oil from the bottom of the distillation tower.

4. The separation process according to claim 1 or 2, characterized in that, The bottom of the primary distillation column uses steam as a reboiling heat source. And / or, the top temperature of the primary distillation column is 45~55℃; And / or, the operating pressure of the primary distillation column is absolute ~0.27 MPa; And / or, the reboiler heat source at the bottom of the primary distillation column is steam of 3.5~3.7 MPa; And / or, the reflux ratio of the primary distillation column is controlled between 4 and 5; And / or, the theoretical number of trays in the primary distillation column is 40-45, the feed position is located on tray 24-26, and the side stream exit position is located on tray 15-17.

5. The separation process according to claim 1 or 2, characterized in that, The bottom of the butane removal column uses steam as a reboiling heat source. And / or, the top temperature of the butane removal column is 45~55℃; And / or, the operating pressure of the butane dehydrogenator is absolute ~1.07 MPa; And / or, the reboiler heat source at the bottom of the butane removal column is 1.0~1.2 MPa ag of steam; And / or, the theoretical number of plates in the butane removal tower is 40-45, and the feed position is located on the 14th to 17th tray.

6. The separation process according to claim 1 or 2, characterized in that, The bottom of the deethanizer uses fuel oil as the reboiling heat source. And / or, the top temperature of the deethaner column is 45~55℃; And / or, the operating pressure of the deethaner is absolute ~1.74 MPa; And / or, the theoretical number of plates in the deethaner is 45-55, and the feed position is located on 6-8 plates.

7. The separation process according to claim 1 or 2, characterized in that, 1) The bottom of the fractionation column uses a reboiler as the reboiler heat source; And / or, the top temperature of the fractionation column is 108~112℃; And / or, the operating pressure of the fractionation column is absolute ~0.16 MPa; And / or, the fractionation column has no reflux; And / or, the fractionation column has a theoretical number of 36 to 42, the feed position is located on the 20th to 24th tray, and the side stream exit position is located on the 15th to 17th tray; 2) The bottom of the C5 separation tower uses steam as the reboiling heat source; And / or, the top temperature of the C5 separation tower is 90~95℃; And / or, the operating pressure of the C5 separation tower is absolute ~0.12 MPa; And / or, the theoretical number of plates in the C5 separation tower is 28 to 30, and the feed position is located on the 21st to 24th tray.

8. A condensate oil separation device, characterized in that, It includes a primary distillation column, a butane removal column feed heat exchanger, a butane removal column, a butane removal column top product heat exchanger for LPG, an ethane removal column, a C5 separation column, and a fractionation column; wherein the primary distillation column, butane removal column, and ethane removal column are connected in sequence, and the primary distillation column is also connected in sequence to the fractionation column and the C5 separation column; a butane removal column feed heat exchanger is provided between the primary distillation column and the butane removal column, and a butane removal column top product heat exchanger for LPG is provided between the butane removal column and the ethane removal column; the primary distillation column is equipped with a primary distillation column side stream extraction and stripping device, and the fractionation column is equipped with a fractionation column side stream extraction and stripping device.

9. A condensate oil separation device according to claim 8, characterized in that, The primary distillation column is equipped with a primary distillation column top air cooler, a primary distillation column top gas circulating water cooler, and a primary distillation column top gas-liquid separator at the top. The primary distillation column top gas outlet is sequentially connected to the primary distillation column top air cooler, the primary distillation column top gas circulating water cooler, and the primary distillation column top gas-liquid separator. The liquid phase outlet of the primary distillation column top gas-liquid separator is divided into two channels: one is connected to the primary distillation column top reflux material inlet, and the other is connected to the heat exchanger between the top product of the butane removal column and the feed of the butane removal column. The primary distillation column is equipped with a primary distillation column bottom steam reboiler at the bottom. The primary distillation column is also equipped with a primary distillation column side stream extraction and stripping device. The top of the butane removal tower is equipped with an overhead air cooler, an overhead circulating water cooler, and an overhead gas-liquid separator. The overhead gas outlet of the butane removal tower is sequentially connected to the overhead air cooler, the overhead circulating water cooler, and the overhead gas-liquid separator. The liquid phase outlet of the overhead gas-liquid separator is divided into two channels: one connected to the overhead reflux material inlet, and the other connected to the overhead product and LPG heat exchanger. The bottom of the butane removal tower is equipped with a bottom steam reboiler. The top of the deethanizer is equipped with a top circulating water cooler and a top gas-liquid separator. The top gas outlet of the deethanizer is sequentially connected to the top circulating water cooler and the top gas-liquid separator. The bottom of the deethanizer is equipped with a bottom reboiler, which is also connected to the heat exchanger between the top product and the liquefied gas of the debutaneizer. The top of the fractionation tower is equipped with a heat exchanger for the fractionation tower top circulation and electro-desalination unit, a primary heat exchanger for the feed to the primary distillation tower, a heat exchanger for the oil-gas and electro-desalination unit at the top of the fractionation tower, and a gas-liquid separator at the top of the fractionation tower. The material outlet at the top of the fractionation tower is sequentially connected to the heat exchanger for the oil-gas and electro-desalination unit at the top of the fractionation tower, the gas-liquid separator at the top of the fractionation tower, and the material inlet at the top of the C5 separation tower. The heat exchanger for the fractionation tower top circulation and electro-desalination unit and the primary heat exchanger for the feed to the primary distillation tower are connected to the reflux inlet at the top of the fractionation tower. The bottom of the fractionation column is equipped with a fractionation column feed heat exchanger, a de-ethanizer bottom reboiler heat exchanger, a primary distillation column feed tertiary heat exchanger, and a fractionation column reboiler; the bottom material outlet of the fractionation column is sequentially connected to the fractionation column feed heat exchanger, the de-ethanizer bottom reboiler heat exchanger, and the primary distillation column feed tertiary heat exchanger. The fractionation tower is also equipped with a fractionation tower side stream extraction and stripping device, which is connected in sequence to the new primary distillation tower feed tertiary heat exchanger and the butane removal tower feed heat exchanger. The C5 separation tower is equipped with a top gas air cooler and a top gas-liquid separator. The top gas outlet of the C5 separation tower is sequentially connected to the top gas air cooler and the top gas-liquid separator. The liquid phase outlet of the top gas-liquid separator is divided into two channels: one is connected to the top reflux material inlet of the C5 separation tower, and the other is the light naphtha product outlet. The C5 separation tower is equipped with a bottom steam reboiler, and the bottom material outlet of the C5 separation tower is also connected to the feed heat exchanger of the butane removal tower.

10. A condensate oil separation device according to claim 8, characterized in that, The primary distillation column is equipped with a primary distillation column top air cooler, a primary distillation column top gas circulating water cooler, and a primary distillation column top gas-liquid separator at the top. The primary distillation column top gas outlet is sequentially connected to the primary distillation column top air cooler, the primary distillation column top gas circulating water cooler, and the primary distillation column top gas-liquid separator. The liquid phase outlet of the primary distillation column top gas-liquid separator is divided into two channels: one is connected to the primary distillation column top reflux material inlet, and the other is connected to the heat exchanger between the top product of the butane removal column and the feed of the butane removal column. The primary distillation column is equipped with a primary distillation column bottom steam reboiler at the bottom. The primary distillation column is also equipped with a primary distillation column side stream extraction and stripping device. The top of the butane descaling tower is equipped with an air cooler for the overhead gas, a circulating water cooler for the overhead gas, a gas-liquid separator for the overhead gas, a primary compressor for the overhead gas, and a secondary compressor for the overhead gas. The overhead gas outlet of the butane descaling tower is sequentially connected to the primary compressor, the secondary compressor, the bottom reboiler heat exchanger, the air cooler, the circulating water cooler, and the gas-liquid separator. The liquid phase outlet of the gas-liquid separator is divided into two channels: one connected to the reflux material inlet at the top of the butane descaling tower, and the other connected to the product-liquefied gas heat exchanger. The bottom of the butane descaling tower is equipped with a bottom reboiler heat exchanger and a bottom steam reboiler. The bottom reboiler heat exchanger and the bottom steam reboiler are connected. The top of the deethanizer is equipped with a top circulating water cooler and a top gas-liquid separator. The top gas outlet of the deethanizer is sequentially connected to the top circulating water cooler and the top gas-liquid separator. The bottom of the deethanizer is equipped with a bottom reboiler, which is also connected to the heat exchanger between the top product and the liquefied gas of the debutaneizer. The top of the fractionation tower is equipped with a heat exchanger for the fractionation tower top circulation and electro-desalination unit, a primary heat exchanger for the feed to the primary distillation tower, a heat exchanger for the oil-gas and electro-desalination unit at the top of the fractionation tower, and a gas-liquid separator at the top of the fractionation tower. The material outlet at the top of the fractionation tower is sequentially connected to the heat exchanger for the oil-gas and electro-desalination unit at the top of the fractionation tower, the gas-liquid separator at the top of the fractionation tower, and the material inlet at the top of the C5 separation tower. The heat exchanger for the fractionation tower top circulation and electro-desalination unit and the primary heat exchanger for the feed to the primary distillation tower are connected to the reflux inlet at the top of the fractionation tower. The bottom of the fractionation column is equipped with a fractionation column feed heat exchanger, a de-ethanizer bottom reboiler heat exchanger, a primary distillation column feed tertiary heat exchanger, and a fractionation column reboiler; the bottom material outlet of the fractionation column is sequentially connected to the fractionation column feed heat exchanger, the de-ethanizer bottom reboiler heat exchanger, and the primary distillation column feed tertiary heat exchanger. The fractionation tower is also equipped with a fractionation tower side stream extraction and stripping device, which is connected in sequence to the new primary distillation tower feed tertiary heat exchanger and the butane removal tower feed heat exchanger. The C5 separation tower is equipped with a top gas air cooler and a top gas-liquid separator. The top gas outlet of the C5 separation tower is sequentially connected to the top gas air cooler and the top gas-liquid separator. The liquid phase outlet of the top gas-liquid separator is divided into two channels: one is connected to the top reflux material inlet of the C5 separation tower, and the other is the light naphtha product outlet. The C5 separation tower is equipped with a bottom steam reboiler, and the bottom material outlet of the C5 separation tower is also connected to the feed heat exchanger of the butane removal tower.

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