CN207627959U - Alkylation reaction product separator and alkylated reaction device - Google Patents

Abstract

The alkylation reaction product separation device and the alkylation reaction device include a first fractionation tower, a second fractionation tower and a third fractionation tower connected in sequence, the first fractionation tower is provided with an inlet for the alkylation reaction product, and the first fractionation tower The top gas phase outlet is connected to the top reflux inlet through the gas compressor, the tower bottom reboiler, the tower top reflux tank; the liquid phase outlet at the bottom of the first fractionation tower is connected to the second fractionation tower raw material inlet, and The top gas phase outlet is connected to the top reflux inlet through the tower top condenser and the tower top reflux tank, a bottom reboiler is arranged at the bottom of the second fractionation tower, and the tower bottom liquid phase outlet is connected with the raw material inlet of the third fractionation tower. The gas phase outlet at the top of the third fractionating tower is connected to the top reflux inlet through the tower top condenser and the tower top reflux tank, and a light fraction outlet is provided, and an alkylation product outlet is arranged at the bottom of the third fractionating tower. The utility model separates the isobutane fraction in the alkylation reaction product in two stages, thereby greatly reducing the energy consumption level of the alkylation device.

Description

Alkylation reaction product separation device and alkylation reaction device

technical field

The utility model relates to a mixture separation device and a chemical reaction device, in particular to an alkylation reaction product separation device and an alkylation reaction device.

Background technique

The alkylation reaction of isobutane and olefins occurs under the action of an acidic catalyst, and the alkylated gasoline obtained through the alkylation reaction does not contain impurities such as sulfur and nitrogen, does not contain aromatics and olefins, and has a higher octane number , is an ideal clean gasoline blending component.

Propylene, butene and pentene can all undergo alkylation reaction with isobutane to produce alkylated gasoline. The octane number of alkylated gasoline produced by butane reaction, propylene is an important chemical raw material, and pentene is a component of light gasoline and has a high octane number. Therefore, industrial alkylation units are mainly based on Isobutane and butene are used as raw materials to produce alkylated gasoline.

At present, the alkylation technologies of isobutane and butene widely used in industry are sulfuric acid alkylation technology and hydrofluoric acid alkylation technology. Although sulfuric acid method and hydrofluoric acid method alkylation technology have been very mature after decades of continuous improvement, the problems of safety and environmental protection are unavoidable. Therefore, researchers have been committed to the development of environmentally friendly Alkylation technology, among which solid acid alkylation technology and ionic liquid alkylation technology are developing rapidly. The solid acid alkylation technology uses acidic solid catalytic materials as catalysts. The alkylation reaction is carried out on the acidic centers on the surface of the catalyst. The solid acid catalyst and the reaction product are easy to separate, non-corrosive, and require low equipment materials. There are safety and environmental risks of acid leakage, and there is no need to consider issues such as online acid replenishment, waste acid regeneration, and acid-soluble oil treatment. Therefore, solid acid alkylation technology is a better alternative to conventional liquid acid alkylation technology. Selection; the ionic liquid alkylation technology uses molten salt called ionic liquid which is liquid at normal temperature as a catalyst. The ionic liquid is composed of inorganic anions and organic cations. Good activity and selectivity, and because ionic liquid has the advantages of low volatility, good thermal stability, wide temperature range in liquid state and easy separation from reaction products, etc., therefore, ionic liquid alkylation technology is also an alternative to conventional liquid An option for acid alkylation technology.

Whether it is conventional liquid acid alkylation technology, solid acid alkylation technology or ionic liquid alkylation technology, a higher molar ratio of isobutane to olefin (or alkene ratio) can improve the alkylation The selectivity of the reaction can obtain better quality alkylated gasoline products. The alkene ratio can be divided into internal alkene ratio and external alkene ratio. The internal alkene ratio refers to the alkene ratio at the reaction active center, usually by stirring Measures such as internal circulation of materials can make the internal alkene ratio have a higher value. The external alkene ratio refers to the alkene ratio in the mixture flow of raw material and circulating isobutane. The isobutane obtained mainly from the product separation unit is recycled back to The external alkene ratio of different alkylation technologies is slightly different. The external alkene ratio of the sulfuric acid alkylation technology is low, and the external alkene ratio of the solid acid alkylation technology is high. The range of external alkene ratio of basement technology is (5-30):1.

In order to ensure a higher external alkene ratio required by the alkylation technology, a relatively large amount of circulating isobutane is separated from the product separation unit and recycled back to the alkylation reaction unit. The flow rate of circulating isobutane is The raw material flow rate of the alkylation reaction is several times that of the raw material flow rate of the alkylation reaction. The energy consumption required for the separation and circulation of isobutane accounts for more than 60% of the total energy consumption of the alkylation unit, which is the main reason for the high energy consumption of the alkylation unit. Therefore, reducing The energy consumption of the circulating isobutane separation process can effectively reduce the energy consumption of the alkylation unit. Reducing the external alkene ratio of the alkylation unit and reducing the flow rate of circulating isobutane is an effective way to reduce the energy consumption required for the separation process of circulating isobutane, but the reduction of the external alkene ratio is often subject to certain restrictions. When the external alkene ratio is lower than 7:1, the selectivity of the alkylation reaction will be significantly affected. Therefore, it is necessary to develop other energy-saving technologies while reducing the external alkene ratio as much as possible.

Utility model content

One of the technical problems to be solved by the utility model is to provide an alkylation reaction product separation device.

The second technical problem to be solved by the utility model is to provide an alkylation reaction device, which can effectively reduce the energy consumption of the circulating isobutane separation process and reduce the operating cost of the alkylation device.

An alkylation reaction product separation device, comprising a first fractionation tower, a second fractionation tower and a third fractionation tower connected in sequence, the first fractionation tower is provided with an alkylation reaction product inlet, and the first fractionation tower The tower top gas phase outlet is connected to the gas compressor inlet, and the gas compressor outlet is connected to the first fractionation tower bottom reboiler, the tower top reflux tank and the first fractionation tower top reflux inlet; The liquid phase outlet is connected to the second fractionation tower raw material inlet, and the second fractionation tower top gas phase outlet is connected to the second fractionation tower top reflux inlet through the tower top condenser and the tower top reflux tank, and the second fractionation tower tower top reflux inlet is connected. A bottom reboiler is arranged at the bottom, and the liquid phase outlet at the bottom of the tower is connected with the raw material inlet of the third fractionation tower, and the gas phase outlet at the top of the third fractionation tower is connected with the third fractionator through the top condenser and the top reflux tank. A reflux inlet is provided at the top of the tower, and a light fraction outlet is provided, and a bottom reboiler is provided at the bottom of the third fractionation tower, and an alkylation product outlet is provided.

An alkylation reaction device, consisting of an alkylation reaction unit and an alkylation reaction product separation unit, the product outlet of the alkylation reaction unit is connected to the alkylation reaction product separation unit; the The alkylation reaction product separation unit adopts the above-mentioned alkylation reaction product separation device.

In the alkylation reaction device provided by the utility model, the alkylation reaction unit is any one of a solid acid alkylation reaction unit, an ionic liquid alkylation reaction unit or a sulfuric acid method alkylation reaction unit.

The beneficial effects of the alkylation reaction product separation device and the alkylation reaction device provided by the utility model are:

The equipment and process of the alkylation reaction product separation device provided by the utility model are simple, and the total energy consumption of the alkylation device can be effectively reduced.

The alkylation reaction product separation device provided by the utility model is suitable for the separation process of the alkylation reaction product of the solid acid alkylation technology, ionic liquid alkylation technology or sulfuric acid alkylation technology, especially for the use of higher external For the solid acid alkylation technology of alkene ratio, the energy saving effect is more obvious.

The alkylation reaction product separation device provided by the utility model is used for the alkylation reaction of isobutane and butene, adopts a two-stage separation method to separate the isobutane fraction in the alkylation reaction product, and reduces the one-stage isobutane removal. The temperature difference between the bottom and top of the alkane tower. The gas phase at the top of the first-stage deisobutanizer is pressurized by a gas compressor to increase the temperature and pressure of the gas phase at the top of the tower, and the gas phase at the top of the tower is used as the heat source of the reboiler at the bottom of the tower, and the phase change heat in the condensation process of the gas phase at the top of the tower is obtained. Fully utilized, the heat load of the bottom reboiler of the primary de-isobutanizer is greatly reduced. Because the first-stage de-isobutanizer separates most of the isobutane cuts, and the energy consumption of separating the isobutane cuts accounts for a relatively high proportion of the total energy consumption of the alkylation unit, therefore, the separation method provided by the utility model can effectively Reduce the overall energy consumption of the alkylation unit.

Description of drawings

Fig. 1 is a schematic flow diagram of an alkylation reaction product separation device provided by the present invention.

Figure 2 is a schematic flow diagram of the separation device and separation method for the alkylation reaction product used in the comparative example.

in:

1-alkylation reaction product; 2-the first fractionation tower; 3-the top gas phase of the first fractionation tower; 4-gas compressor inlet buffer tank; 6-gas compressor; 8-reboil at the bottom of the first fractionation tower Device; 10-the top reflux tank of the first fractionation tower; 13-the supplementary reboiler at the bottom of the first fractionation tower; 14-the bottom discharge of the first fractionation tower; 15-the second fractionation tower; 16-the second fractionation tower Gas phase at the top of the tower; 17-the top condenser of the second fractionating column; 19-the reflux tank at the top of the second fractionating column; 22-the light fraction outlet; 23-the bottom reboiler of the second fractionating column; 24-the second fractionating column 25-the third fractionation tower; 26-the gas phase at the top of the third fractionation tower; 27-the condenser at the top of the third fractionation tower; 29-the third fractionation tower top reflux tank; 31-the light fraction outlet; 32-reboiler at the bottom of the third fractionation tower; 33-alkylation product outlet; 5, 7, 9, 11, 12, 18, 20, 21, 28, 30-pipelines.

Detailed ways

The specific implementation of the utility model will be further described below, but the utility model is not limited thereby.

The "middle" of the container referred to in the description refers to the position of 30%-70% of the container from top to bottom.

An alkylation reaction product separation device, comprising a first fractionation tower, a second fractionation tower and a third fractionation tower connected in sequence, the middle part of the first fractionation tower is provided with an alkylation reaction product inlet, and the first fractionation tower The gas phase outlet at the top of the fractionating tower is connected to the inlet of the gas compressor, and the outlet of the gas compressor is communicated with the top reflux inlet of the first fractionating tower through the reboiler at the bottom of the first fractionating tower and the top reflux tank; The bottom liquid phase outlet is connected to the raw material inlet in the middle part of the second fractionating tower, and the gas phase outlet at the top of the second fractionating tower is connected to the top reflux inlet of the second fractionating tower through the tower top condenser and the tower top reflux tank. A bottom reboiler is arranged at the bottom of the fractionating tower, and the liquid phase outlet at the bottom of the tower is connected with the raw material inlet in the middle of the third fractionating tower, and the gas phase outlet at the top of the third fractionating tower passes through the top condenser and the top reflux The tank is connected to the top reflux inlet of the third fractionation column, and is provided with a light fraction outlet, and the bottom of the third fractionation column is provided with a bottom reboiler, and is provided with an alkylation product outlet.

Preferably, the top reflux tank of the first fractionation tower is provided with an outlet for the light fraction of the first fractionation tower.

Preferably, the top reflux tank of the second fractionation tower is provided with an outlet for the light fraction of the second fractionation tower.

In the alkylation reaction product separation device provided by the utility model, preferably, the first fractionation tower is a first-stage deisobutanizer, and the second fractionation tower is a second-stage deisobutanizer. The third fractionation tower is a de-butanizer.

An alkylation reaction device, consisting of an alkylation reaction unit and an alkylation reaction product separation unit, the product outlet of the alkylation reaction unit is connected to the alkylation reaction product separation unit; the The alkylation reaction product separation unit adopts the above-mentioned alkylation reaction product separation device.

In the alkylation reaction device provided by the utility model, the alkylation reaction unit is any one of a solid acid alkylation reaction unit, an ionic liquid alkylation reaction unit or a sulfuric acid method alkylation reaction unit.

The application method of the alkylation reaction device provided by the utility model comprises the following steps:

(1) In the alkylation reaction unit, the alkylation raw material is contacted with an acidic catalyst to perform an alkylation reaction, and the reacted material is discharged from the alkylation reaction unit as an alkylation reaction product;

(2) The alkylation reaction product is introduced into the first fractionating tower, and after the gas phase flow drawn from the top of the first fractionating tower is pressurized by the gas compressor, it is used as the heat source of the reboiler at the bottom of the first fractionating tower, after heat exchange And the condensed tower overhead flow part or all returns to the tower top as the reflux of the first fractionation tower;

(3) The bottom liquid stream of the first fractionating tower is introduced in the second fractionating tower, and after the gas phase stream drawn from the top of the second fractionating tower is condensed and cooled, a part returns to the tower top as the reflux of the second fractionating tower, and the other part Lead out as separated light fraction;

(4) The bottom liquid stream of the second fractionating tower is introduced in the third fractionating tower, and after the gas phase stream drawn from the top of the third fractionating tower is condensed and cooled, a part returns to the tower top as the reflux of the third fractionating tower, and the other part As the resulting light fraction is withdrawn, the bottom liquid phase stream of the third fractionation column is used as the alkylation product.

The alkylation reaction product separation device provided by the utility model is used in the alkylation reaction process of isobutane and butene, comprising the following steps:

(1) In the alkylation reaction unit, the C4 fraction containing isobutane and butene is contacted with an alkylation catalyst to perform an alkylation reaction, and the reacted material is discharged from the alkylation reaction unit as an alkylation reaction product;

(2) The alkylation reaction product is introduced into the first-stage de-isobutanizer tower, and the gas phase stream drawn from the top of the first-stage de-isobutanizer tower is pressurized by a gas compressor, and then reboiled at the bottom of the first-stage de-isobutanizer tower The heat source of the device, part or all of the overhead stream after heat exchange and condensation returns to the top of the tower as the reflux of the first-stage de-isobutanizer;

(3) The liquid phase flow at the bottom of the first-level de-isobutanizer is introduced into the second-level de-isobutanizer, and the gas-phase stream drawn from the top of the second-level de-isobutanizer is condensed and cooled, and part of it is used as a second-level de-isobutanizer The reflux of the alkane tower returns to the top of the tower, and the other part is drawn as the separated isobutane fraction;

(4) The liquid phase stream at the bottom of the secondary de-butanizer tower is introduced into the de-n-butanizer tower, and the gas phase stream drawn from the top of the de-n-butanizer tower is condensed and cooled, and a part of it returns to the tower as the reflux of the de-n-butanizer tower The other part is taken out as the separated n-butane fraction, and the liquid phase stream at the bottom of the de-butanizer is used as the alkylated gasoline product.

The alkylation reaction product from the alkylation reaction unit is mainly composed of isobutane, n-butane and alkylated gasoline, wherein the isobutane contains the alkylation reaction raw material remaining after the alkylation reaction The isobutane and the circulating isobutane from the product separation unit, n-butane does not participate in the alkylation reaction, it is mainly brought in by the alkylation feedstock, and the alkylation gasoline is the alkylation reaction of isobutane and olefins reaction product.

The top of the first-stage de-butanizer tower and the top of the second-stage de-isobutanizer are separated to obtain isobutane fractions, and the top of the de-normal butanizer is separated to obtain normal-butane fractions, tower The bottom stream is used to obtain alkylated gasoline, wherein most of the isobutane fraction is returned to the alkylation reaction unit as recycled isobutane, and a small part is sent out as a by-product of the isobutane fraction.

The isobutane fraction separated by the first-stage de-isobutanizer accounts for 50% to 90% of the isobutane fraction in the alkylation reaction product.

The top of the first-stage de-isobutanizer requires pressurization equipment to pressurize the isobutane fraction. The compression ratio of the pressurization equipment ranges from 1.3 to 4.5:1, and the absolute pressure at the outlet of the pressurization equipment is 1.0 to 3.2 MPa.

Preferably, a make-up reboiler at the bottom of the primary de-isobutanizer is provided to provide residual heat required for isobutane fraction separation.

In said alkylation reaction product separation unit, the separation of isobutane fraction adopts the method of two-stage separation, wherein the first-stage separation is completed by the first-stage deisobutanizer, and the second-stage separation is completed by the second-stage deisobutanizer. isobutane column to complete. The first-stage de-isobutanizer separates most of the isobutane fraction in the alkylation reaction product, and the remaining small part of the isobutane fraction is separated by the second-stage de-isobutanizer, and the alkylation is separated by a two-stage separation method. After the isobutane fraction in the reaction product, the temperature difference between the bottom and the top of the first-stage de-isobutanizer is not large, and a heat source with a lower temperature can be used as the heat source for the bottom reboiler of the first-stage de-isobutanizer.

The one-stage de-isobutanizer adopts a separation method different from conventional separation methods. The conventional separation method is to directly condense and cool the gaseous phase stream at the top of the primary de-isobutanizer tower, while the alkylation reaction needs to adopt a higher external alkene ratio, so that the flow rate of circulating isobutane is equal to the flow rate of the alkylation feedstock. Several times, because the first-stage de-isobutanizer separates most of the isobutane fractions in the alkylation reaction product, the phase change heat of the first-stage de-isobutanizer overhead gas phase stream condensation process is very considerable, but due to the first-stage de-isobutanizer The temperature of the overhead stream of the isobutanizer is relatively low and cannot be used as a heat source. The heat required for the separation process is all provided by the bottom reboiler of the first-stage de-isobutanizer, so that the first-stage de-isobutanizer bottom The reboiler has a large heat load and high energy consumption. The separation method adopted in the utility model is to pressurize the gas phase stream at the top of the first-stage isobutanizer with a gas compressor, and the temperature and pressure of the gas-phase stream at the top of the pressurized tower are increased, which can be used as a first-stage isobutanizer The heat source of the bottom reboiler of the alkane tower, the gas phase stream at the top of the tower is liquefied in the bottom reboiler of the first-stage deisobutanizer, the phase change heat of the tower top stream has been fully utilized, and the first-stage de-isobutanizer separates A small portion of the required heat is provided by a bottom make-up reboiler. The first-stage de-isobutanizer separates most of the isobutane fractions from the alkylation reaction product. After adopting the separation method provided by the utility model, the energy consumption required for the separation of the first-stage de-isobutanizer is greatly improved. Since the energy consumption required for the separation of the isobutane fraction accounts for a relatively high proportion of the total energy consumption of the alkylation unit, the total energy consumption of the alkylation unit has also been significantly reduced.

The secondary de-isobutanizer adopts a conventional separation method, and its main function is to separate the remaining isobutane fraction from the alkylation reaction product. Because the top of the secondary de-isobutanizer is the isobutane fraction, the bottom of the tower is For n-butane and alkylated gasoline, the temperature difference between the bottom and the top of the tower is relatively large. If the same separation method as the one-stage de-isobutanizer is used, the gas compressor of the gas phase stream at the top of the tower needs to adopt a higher compression ratio. , and the secondary de-isobutanizer only separates a small amount of isobutane fraction in the alkylation reaction product, therefore, the secondary de-isobutanizer should adopt a conventional separation method. Most of the isobutane fraction separated from the top of the secondary de-isobutanizer is mixed with the isobutane fraction obtained from the top of the primary de-isobutanizer and returned to the alkylation reaction unit as circulating isobutane. Part of the isobutane fraction is sent out as a by-product, and the n-butane and alkylated gasoline at the bottom of the secondary de-butanizer are sent to the de-butanizer for further separation.

Due to the small content of n-butane in the alkylation reaction product, the de-n-butanizer adopts a conventional separation method, and its main function is to separate the n-butane in the alkylation reaction product from the alkylated gasoline. The n-butane fraction obtained from the top of the de-n-butanization tower is sent out as a by-product, and the alkylated gasoline product is obtained at the bottom of the tower.

The gas compressor of the gas phase at the top of the first-stage deisobutanization tower is an important equipment in the separation method provided by the utility model, and the gas phase at the top of the tower is acted on by the gas compressor, which improves the pressure and temperature of the gas phase at the top of the tower, Make the temperature of the gas phase at the top of the first-stage deisobutanization tower meet the requirements of being the heat source for reboiling at the bottom of the first-stage de-isobutanization tower, and the phase change heat during the condensation of the gas phase at the top of the tower is fully utilized, so that the first-stage de-isobutanization The energy consumption of the tower separation process is greatly reduced.

The specific implementation of the alkylation reaction product separation device and separation method provided by the utility model will be described in detail below with reference to the accompanying drawings.

Accompanying drawing 1 is the schematic process flow diagram of the separation device and separation method of the alkylation reaction product provided by the present invention. The alkylation reaction product separation device includes a first fractionation tower 2, a second fractionation tower 15 and a third fractionation tower 25 connected in sequence, the middle part of the first fractionation tower 2 is provided with an alkylation reaction product inlet 1, and the The first fractionation tower top gas phase 3 outlet is connected to the gas compressor 6 inlets, and the gas compressor 6 outlets are communicated with the first fractionation tower top reflux inlet through the first fractionation tower bottom reboiler 8, the tower top reflux tank 10; The liquid phase 14 outlet at the bottom of the first fractionating tower is connected to the raw material inlet in the middle part of the second fractionating tower 15, and the gas phase 16 outlet at the top of the second fractionating tower is connected to the second fractionating tower through the top condenser 17 and the top reflux tank 19. Fractionation tower top reflux inlet, the bottom of the second fractionation tower 15 is provided with a bottom reboiler 23, the liquid phase outlet at the bottom of the tower communicates with the raw material inlet in the middle of the third fractionation tower 25, and the third The gas phase 26 outlet at the top of the fractionation tower is connected to the top reflux inlet of the third fractionation tower 25 through the tower top condenser 27 and the top reflux tank 29, and the light fraction outlet is set, and the bottom of the third fractionation tower is provided with a bottom reboiler Device 32, and the alkylation product 33 outlet is set.

Preferably, the first fractionation tower 2 is a first-stage de-isobutanizer, the second fractionation tower 15 is a second-stage de-isobutanizer, and the third fractionation tower 25 is a de-n-butanizer tower. During the use of the above-mentioned alkylation reaction product separation device, the alkylation reaction product from the alkylation reaction unit is introduced into the primary de-isobutanizer 2 through the pipeline 1, and the top of the primary de-isobutanizer 2 is After the gaseous phase flow is drawn from the pipeline 3, it enters the gas compressor inlet buffer tank 4, and then enters the gas compressor 6 through the pipeline 5. After pressurization, the temperature and pressure of the gaseous phase flow at the top of the tower increase, and then it is introduced into the first-stage degasser through the pipeline 7. The reboiler 8 at the bottom of the isobutanizer tower provides the heat required for the separation of the primary de-isobutanizer 2, and the gaseous phase stream at the top of the tower is condensed in the reboiler 8 at the bottom of the primary de-isobutanizer tower, and the gas phase at the top of the tower is The phase change heat of the stream is fully utilized, and the condensed tower overhead gas stream is introduced into the first-stage deisobutanizer tower top reflux tank 10 through the pipeline 9, and a part of the liquid phase in the first-stage deisobutanizer tower top reflux tank 10 As reflux, it is introduced into the top of the primary de-isobutanizer 2 via line 11, and most of the rest is returned to the alkylation reaction unit via line 12 as recycled isobutane. Insufficient heat in the separation process of the primary de-isobutanizer 2 is provided by a complementary reboiler 13 at the bottom of the primary de-isobutanizer.

The liquid phase flow at the bottom of the first-level de-isobutanizer 2 is introduced into the second-level de-isobutanizer 15 through the pipeline 14, and the second-level de-isobutanizer 15 adopts a conventional separation method. After the gas phase stream at the top of the tower is drawn through the pipeline 16, After being condensed and cooled by the tower top condenser 17, it is introduced into the top reflux tank 19 of the secondary de-isobutanizer tower through the pipeline 18, and a part of the liquid phase in the top reflux tank 19 of the secondary de-isobutanizer is used as reflux through the pipeline 20 Introduced into the top of the secondary de-isobutanizer 15, a part of it is mixed with the circulating isobutane in the pipeline 12 via the pipeline 21 as circulating isobutane and returned to the alkylation reaction unit, and the rest is passed through the pipeline 22 as a by-product of the isobutane fraction delivery. The heat required for separation in the primary de-isobutanizer 15 is provided by the bottom reboiler 23 of the primary de-isobutanizer, and the bottom liquid phase is introduced into the de-n-butanizer 25 through the pipeline 24 .

The de-n-butanizer 25 adopts a conventional separation method. After the gas phase stream at the top of the tower is drawn through the pipeline 26, after being condensed and cooled by the tower top condenser 27, it is introduced into the de-normal-butanizer tower top reflux tank 29 through the pipeline 28, and the de-normalization A part of the liquid phase in the reflux tank 29 at the top of the butane tower is introduced into the top of the normal-butanizer 25 through the pipeline 30 as reflux, and the other part is sent out through the pipeline 31 as a by-product of the n-butane fraction. The heat required for separation in the de-n-butanizer 25 is provided by the reboiler 32 at the bottom of the de-n-butanizer, and the liquid stream at the bottom of the tower is sent out through the pipeline 33 as an alkylated gasoline product.

The following examples will further illustrate the practical application of the utility model, but the utility model is not limited thereto.

Example 1

The alkylation reaction product comes from the isobutane and butene alkylation reaction unit of the solid acid alkylation technology. The solid acid alkylation catalyst used is a solid acid catalyst containing Y-type molecular sieve, produced by Catalyst Changling Branch of China Petroleum & Chemical Corporation, and the catalyst brand is AIB-2. The C4 fraction of the raw material for the alkylation reaction was obtained from Beijing Yanshan Branch of China Petrochemical Corporation, and its composition is shown in Table 1; the external alkene ratio is 25:1.

The separation of the alkylation reaction product adopts the alkylation reaction product separation device shown in accompanying drawing 1, wherein, the first fractionation tower is a one-stage deisobutanizer, and the second fractionation tower is a two-stage deisobutanizer, The third fractionation tower is a de-butanizer. The main structural parameters of the alkylation reaction product separation device are shown in Table 2; the main alkylation reaction conditions and operating conditions of the separation device are shown in Table 3. The main properties of alkylated gasoline are shown in Table 4, the material balance data are shown in Table 5, and the energy consumption of the alkylation reaction product separation process is shown in Table 6.

Example 2

The alkylation reaction product comes from the isobutane and butene alkylation reaction unit of sulfuric acid alkylation technology. The catalyst is commercially available concentrated sulfuric acid having a concentration of 99.2% by mass. The C4 fraction of the raw material for the alkylation reaction is the same as in Example 1, and the ratio of the external alkanes used in the sulfuric acid alkylation technology is 11:1, wherein the external alkanes provided by the primary de-isobutanizer and the secondary de-isobutanizer The ene ratio is 8:1.

The separation of the alkylation reaction product adopts the alkylation reaction product separation device shown in accompanying drawing 1, wherein, the first fractionation tower is a one-stage deisobutanizer, and the second fractionation tower is a two-stage deisobutanizer, The third fractionation tower is a de-butanizer. The main structural parameters of the alkylation reaction product separation device are shown in Table 2; the main alkylation reaction conditions and operating conditions of the separation device are shown in Table 3. The main properties of alkylated gasoline are shown in Table 4, the material balance data are shown in Table 5, and the energy consumption of the alkylation reaction product separation process is shown in Table 6.

Comparative example 1

The alkylation reaction unit and the obtained alkylation reaction product are the same as in Example 1.

The separation of the alkylation reaction product adopts the separation device of the alkylation reaction product shown in accompanying drawing 2, and the difference from Example 1 is that the isobutane fraction in the alkylation reaction product is separated in the deisobutanizer 2 , the de-isobutanizer does not adopt the secondary separation method, the tower top gas phase of the de-isobutanizer is condensed and cooled by the tower top condenser 34, and then enters the tower top reflux tank 10, and the heat required for the separation process is all regenerated from the bottom of the tower Boiler 8 is provided. The main structural parameters of the alkylation reaction product separation device are shown in Table 2; the main alkylation reaction conditions and operating conditions of the separation device are shown in Table 3. The main properties of alkylated gasoline are shown in Table 4, the material balance data are shown in Table 5, and the energy consumption of the alkylation reaction product separation process is shown in Table 6.

As can be seen from Table 6: the total energy consumption of Example 1 is less than that of Comparative Example 1. Compared with Comparative Example 1, the energy consumption of the alkylation reaction product separation process of Example 1 is reduced by about 20%. The method can reduce the energy consumption level of the alkylation unit under the condition that the external alkene ratio is 25:1.

Comparative example 2

The alkylation reaction unit and the obtained alkylation reaction product are the same as in Example 2.

Adopt the alkylation reaction product separation device shown in accompanying drawing 2, the difference with embodiment 2 is that the difference with embodiment 1 is that the isobutane fraction in the alkylation reaction product is separated in deisobutanizer 2 , the de-isobutanizer does not adopt the secondary separation method, the tower top gas phase of the de-isobutanizer is condensed and cooled by the tower top condenser 34, and then enters the tower top reflux tank 10, and the heat required for the separation process is all regenerated from the bottom of the tower Boiler 8 is provided. The main structural parameters of the alkylation reaction product separation device are shown in Table 2; the main alkylation reaction conditions and operating conditions of the separation device are shown in Table 3. The main properties of alkylated gasoline are shown in Table 4, the material balance data are shown in Table 5, and the energy consumption of the alkylation reaction product separation process is shown in Table 6.

As can be seen from Table 6: the total energy consumption of Example 2 is less than that of Comparative Example 2. Compared with Comparative Example 2, the energy consumption of the alkylation reaction product separation process of Example 2 is reduced by about 10%. The method can reduce the energy consumption level of the alkylation unit under the condition that the external alkene ratio is 11:1.

Table 1

Mass Composition of Alkylation Feedstock quality% propane 0.130 Isobutane 47.590 n-butane 13.794 Butene 9.215 Isobutylene 0.130 Anti-butene 17.377 Butene 11.754 C5+ 0.010 total 100.00

Table 2

table 3

Table 4

table 5

Example 1 Example 2 Comparative example 1 Comparative example 2 Alkylation reaction product feed, t/h 352.0 137.8 352.0 137.5 Circulating isobutane, t/h 321.8 107.6 321.8 107.3 Isobutane fraction, t/h 2.4 2.4 2.4 2.4 n-butane fraction, t/h 4.0 4.1 4.0 4.1 Alkylated gasoline, t/h 23.8 23.7 23.8 23.7

Table 6

Example 1 Example 2 Comparative example 1 Comparative example 2 Energy consumption converted from electricity consumption, MJ/t paraffin oil 2475.4 1587.0 610.0 534.2 Energy consumption converted from steam consumption, MJ/t paraffin oil 4884.7 2605.4 8327.9 4005.5 Energy consumption converted from circulating water consumption, MJ/t paraffin oil 563.2 434.0 1027.5 570.5 Total energy consumption, MJ/t paraffin oil 7923.3 4626.4 9965.4 5110.2

Claims (10)

1. a kind of alkylation reaction product separator, including the first fractionating column, after-fractionating tower and the third that are sequentially communicated are divided Tower is evaporated, alkylation reaction product entrance, first fractionator overhead gaseous phase outlet connection is arranged in first fractionating column Gas compressor entrance, gas compressor are exported through the first fractionating column tower bottom reboiler, return tank of top of the tower and the first fractionation column Push up reflux inlet connection；The first fractionation column bottom liquid-phase outlet connection after-fractionating tower feed(raw material)inlet, second Fractionator overhead gaseous phase outlet is connected to after-fractionating column overhead reflux inlet through overhead condenser, return tank of top of the tower, and described the Tower bottom reboiler is arranged in two fractionation column bottoms, and bottom of tower liquid-phase outlet is connected to the third fractionating column feed(raw material)inlet, described Third fractionator overhead gaseous phase outlet is connected to third fractionator overhead reflux inlet, and sets through overhead condenser, return tank of top of the tower Fraction outlets are set, tower bottom reboiler is arranged in the third fractionation column bottom, and alkylation products outlet is arranged.

2. alkylation reaction product separator described in accordance with the claim 1, which is characterized in that first fractionation column It pushes up return tank and the first fractionating column fraction outlets is set.

3. according to alkylation reaction product separator as claimed in claim 1 or 2, which is characterized in that the after-fractionating After-fractionating tower fraction outlets are arranged in column overhead return tank.

4. alkylation reaction product separator described in accordance with the claim 3, which is characterized in that first fractionating column is Level-one deisobutanizer, the after-fractionating tower are two level deisobutanizer, and the third fractionating column is de- normal butane tower.

5. a kind of alkylated reaction device, is made of alkylated reaction unit and alkylation reaction product separative element, described Alkylation reaction product separative element described in the product exit connection of alkylated reaction unit；The alkylation reaction product Separative element includes the first fractionating column, after-fractionating tower and third fractionating column being sequentially communicated, first fractionating column setting Alkylation reaction product entrance, the first fractionator overhead gaseous phase outlet are connected to gas compressor entrance, gas compressor Outlet is connected to through the first fractionating column tower bottom reboiler, return tank of top of the tower with the first fractionator overhead reflux inlet；Described first The fractionation column bottom liquid-phase outlet connection after-fractionating tower feed(raw material)inlet, after-fractionating column overhead gaseous phase outlet are cold through tower top Condenser, return tank of top of the tower are connected to after-fractionating column overhead reflux inlet, and tower bottom reboiler is arranged in the after-fractionating tower bottom of tower, Bottom of tower liquid-phase outlet is connected to the third fractionating column feed(raw material)inlet, and the third fractionator overhead gaseous phase outlet is through tower top Condenser, return tank of top of the tower are connected to third fractionator overhead reflux inlet, and fraction outlets are arranged, the third fractionating column Tower bottom reboiler is arranged in bottom of tower, and alkylation products outlet is arranged.

6. alkylated reaction device according to claim 5, which is characterized in that the first fractionator overhead return tank First fractionating column fraction outlets are set.

7. according to alkylated reaction device described in claim 5 or 6, which is characterized in that the after-fractionating column overhead is returned It flows tank and after-fractionating tower fraction outlets is set.

8. alkylated reaction device according to claim 7, which is characterized in that first fractionating column takes off different for level-one Butane tower, the after-fractionating tower are two level deisobutanizer, and the third fractionating column is de- normal butane tower.

9. alkylated reaction device according to claim 8, which is characterized in that the level-one deisobutanizer bottom of tower is set Set bottom of tower supplement reboiler.

10. alkylated reaction device according to claim 5, which is characterized in that the alkylated reaction unit is solid Any one of body acid alkylation reaction member, ionic liquid allcylation reaction member or sulfuric acid process alkylated reaction unit.