CN112370814A

CN112370814A - Filler extraction tower, application thereof and residual oil solvent deasphalting method

Info

Publication number: CN112370814A
Application number: CN202011183941.5A
Authority: CN
Inventors: 唐晓津; 鲍迪; 任小甜; 朱振兴
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2020-10-29
Filing date: 2020-10-29
Publication date: 2021-02-19

Abstract

A filler extraction tower and application thereof and a residual oil solvent deasphalting method are provided, wherein the filler extraction tower consists of a shell, a raw material inlet positioned in the middle of the shell, an extraction solvent inlet positioned at the lower part, a tower top extraction phase outlet, a tower bottom raffinate phase outlet and extraction structured packing, and the extraction structured packing is filled in the shell of the extraction tower; the extraction structured packing is a grid type packing. The filler extraction tower provided by the invention is suitable for the deasphalting process of a heavy oil solvent, and has high separation efficiency and large treatment capacity.

Description

Filler extraction tower, application thereof and residual oil solvent deasphalting method

Technical Field

The invention relates to separation equipment in the fields of oil refining and chemical industry and an application method thereof, in particular to an extraction separation tower and an application method thereof.

Background

Petroleum resources in the world show the trend of heavy oil conversion and poor oil conversion, environmental protection laws and regulations in various countries are increasingly strict, higher requirements are put on the light oil conversion and the cleanness of oil refining products and the cleanness and the low carbon of refining processes, and the heavy oil conversion technology is more and more emphasized. Solvent deasphalting is one of the important approaches for the conversion of heavy oil into light oil, residual oil can be separated to obtain the deasphalted asphalt rich in asphaltene and metals and high in carbon residue and the deasphalted oil with low impurity content and low carbon residue, and the combined process of the deasphalting and the deasphalted oil is very attractive in the aspect of deep processing of heavy oil.

The residual oil solvent deasphalting for producing light oil is to use heavy hydrocarbon such as pentane as solvent, remove all asphaltenes and most metals in heavy oil by using heavy solvent to obtain deasphalted oil with high yield, and carry out hydrogenation treatment on the deasphalted oil, wherein the deasphalted oil after hydrogenation can be used as catalytic cracking raw material or hydrocracking raw material, so as to realize high yield of light oil. It is expected that large solvent deasphalting equipment and technology with high deasphalted oil yield will play a greater role in heavy oil processing and bring higher economic benefits to enterprises in the environment of shortage of petroleum resources and increasing demand for petroleum products.

The packed extraction tower is widely applied to oil refining and chemical industry as a common liquid/liquid separation mass transfer device. The filler is a core internal member of the filler extraction tower, and the structure of the filler extraction tower directly influences the mass transfer separation efficiency of the extraction tower. Common extraction packing is generally divided into random packing and regular packing, and compared with random packing, regular packing has the advantages of pressure reduction, large flux, difficult blockage and the like due to the regular geometric shape. The structured packing can be divided into corrugated plate packing, grid packing and the like, and generally, the grid packing has higher treatment capacity and the corrugated packing has better separation performance.

CN104289172A discloses a guide grid structured packing, which is composed of multiple layers of grid plates perpendicular to each other, and the grid plates are provided with guide holes in the same direction, so that the packing has a large handling capacity and is not easy to block. CN104209080A discloses a corrugated packing with tongue-shaped plates, which is made by splicing multiple corrugated plates 90 ° in pairs into a disc shape, wherein the slope of each corrugated plate is provided with at least two rows and at least one row of tongue pieces, the directions of the tongue pieces on two adjacent slopes are opposite, and the directions of the tongue pieces on two parallel slopes are the same. The filler has the advantages of reasonable structure, high aperture ratio, higher running flux, stronger coking resistance and anti-blocking capability, higher mass transfer efficiency and capability of meeting the requirements of large treatment capacity and treatment of dirty and blocked viscous material systems. CN111215020A discloses a filler grid, outwards by the center, is equipped with the multilayer grid, through draw-in groove, slider and the bolt that the central grid set up, can be according to actual need connection grid, convenient dismantlement and transportation. CN202427449U discloses a slant pore plate grid filler, which is composed of a vertical plate and a slant plate, and has good one-step forming strength and high processing capacity. In the existing packing components, the mass transfer efficiency is low and the separation effect is insufficient; some designs have more fine structures such as tongues, can promote the breakage of liquid drops, are favorable for improving the mass transfer efficiency, and the higher the aperture ratio is, the more favorable the mass transfer efficiency is. Meanwhile, the more the fine structure of the packing member is, the larger blocking effect is generated on two phases flowing up and down in the tower, and the flux is further reduced.

Disclosure of Invention

The invention aims to solve the technical problem of providing a filler extraction tower with high mass transfer efficiency and high treatment capacity, application thereof and a residual oil solvent deasphalting method on the basis of the prior art.

In a first aspect, the invention provides a filler extraction column, which comprises a shell, a raw material inlet positioned in the middle of the shell, an extraction solvent inlet positioned at the lower part, a tower top extraction phase outlet, a tower bottom raffinate phase outlet and extraction structured packing, wherein the extraction structured packing is filled in the shell of the extraction column.

The extraction structured packing is formed by stacking one or more extraction packing units; the extraction filler unit is composed of at least two groups of obliquely staggered grid plate groups, the included angle of the adjacent grid plate groups is 20-120 degrees, the grid plate groups are composed of grid plates which are parallel to each other, the included angle between each grid plate and the horizontal plane is 0-90 degrees, and barrier strips are arranged on the cross sections between the adjacent grid plate groups and are parallel to the grid plate group on one side.

In a second aspect, the invention provides an application method of the above-mentioned filler extraction tower, wherein an extraction solvent enters the filler extraction tower from an extraction solvent inlet and moves upwards, a heavy raw material to be separated is introduced into the filler extraction tower from a raw material inlet and moves downwards, the two phases are in full contact mass transfer in an extraction section, a light component in the heavy raw material enters a solvent phase, and the rest components continue to move downwards and are discharged out of the extraction tower from a raffinate phase outlet; the solvent and light components pass through the coalescence section to enable the carried immiscible heavy raw material to be coalesced and separated, and the solvent leaving the coalescence section is discharged out of the extraction tower from an extract phase outlet.

In the third aspect, the invention provides a residual oil solvent deasphalting method, the filler extraction tower is adopted, a solvent is taken as a continuous phase, enters the filler extraction tower from an extraction solvent inlet and moves upwards, residual oil is introduced into the filler extraction tower from a raw material inlet and moves downwards as a dispersed phase, the two phases are fully contacted and transferred in an extraction section, light components in the residual oil enter the solvent phase, residual oil liquid drops continuously move downwards, enter a residual oil space at the bottom of the tower and are discharged out of the extraction tower from a raffinate phase outlet; the solvent leaving the extraction section passes through the coalescence section to coalesce and separate the entrained dispersed phase droplets, and the solvent leaving the coalescence section is discharged out of the extraction column through an extract phase outlet; the solvent is selected from one or more of propane, butane and pentane.

Compared with the prior art, the filler extraction tower, the application thereof and the residual oil solvent deasphalting method provided by the invention have the beneficial effects that:

the extraction regular packing and the coalescence regular packing are filled in the packing extraction tower provided by the invention, so that the disturbance to the liquid flowing process can be obviously increased, the surface updating effect in the liquid-liquid mass transfer process is promoted, and the extraction efficiency is improved. In addition, two sets of grid pieces are arranged alternately, gaps are reserved between the grid pieces, flowing dead zones caused by wall effects can be avoided, and the uniformity of fluid distribution is improved. The inclined and regular flow channel arrangement can avoid the flow channel blockage caused by deposition. The coalescence regular packing has good affinity with the deoiled asphalt, and can effectively coalesce and remove the deoiled asphalt carried by the deasphalted oil. The filler extraction tower has the advantages of simple structure, convenient and quick installation, high extraction and separation efficiency and large flooding flux.

The method for removing the asphalt from the heavy oil has the advantages that the used filler extraction tower is convenient and quick to install, the extraction and separation efficiency is high, the yield of the deasphalted oil can be 60-80% when the method is used for removing the asphalt from the residual oil solvent, and the height of a mass transfer unit can be less than 0.2 m. The treatment flux can be higher than 80m³/m²/h。

Drawings

FIG. 1 is a schematic diagram of the structure of one embodiment of a packed extraction column.

FIG. 2 is a schematic diagram of the structure of one embodiment of the extraction structured packing.

FIG. 3 is a schematic diagram of the structure of a coalescing structured packing.

FIG. 4 is a schematic diagram of an extractive separation-solvent recovery scheme.

Fig. 5 is a schematic view of the structure of the grid packing used in comparative example 1.

Description of reference numerals:

1-grid segments of the first grid segment set 2-grid segments of the second grid segment set

3-opening 4-arc sheet

5-baffle strip 6-heavy oil raw material inlet

7-extraction solvent inlet 8-extraction phase outlet

9-raffinate phase outlet 10-liquid phase interface

11-coalescence section 12-extraction section

13-extraction column shell 14-solvent recovery column

15-extraction column 16-Grating strip group I of structured packing of comparative example 1

17-Gray band set II of structured packing of comparative example 1

Detailed Description

The specific embodiments of the packing extraction tower and the application method thereof, and the solvent deasphalting method provided by the present invention are described in detail as follows:

in one aspect, the invention provides a filler extraction tower, which comprises a shell, a raw material inlet positioned in the middle of the shell, an extraction solvent inlet positioned in the lower part, a tower top extraction phase outlet, a tower bottom raffinate phase outlet and extraction structured packing, wherein the extraction structured packing is filled in the shell;

the extraction structured packing is formed by splicing one or more extraction packing units; the extraction filler unit is composed of at least two groups of grid sheet groups which are obliquely staggered, the included angle of the adjacent grid sheet groups is 20-120 degrees, the grid sheet groups are composed of grid sheets which are parallel to each other, the included angle of the grid sheets and the horizontal plane is 0-90 degrees, and barrier strips are arranged on the cross sections between the adjacent grid sheet groups and are parallel to the grid sheet group on one side.

Optionally, the extraction section from the raw material inlet to the extraction solvent inlet is filled with the extraction regular packing, and the coalescence section from the raw material inlet to the top of the tower is filled with the coalescence regular packing.

Optionally, the structured coalescence packing consists of one or more structured coalescence packing elements; the coalescence packing unit is composed of at least two groups of obliquely staggered grid sheet groups, the included angle of the adjacent grid sheet groups is 20-120 degrees, each grid sheet group is composed of mutually parallel grid sheets, the included angle between each grid sheet and the horizontal plane is 0-90 degrees, and barrier strips are arranged on the sections between the mutually staggered grid sheet groups and are parallel to the grid sheet group on one side; the coalescence filler unit is made of stainless steel, and the surface of the coalescence filler unit is subjected to sand blasting treatment.

Optionally, the extraction filler unit is formed by two grating sheet groups with different inclination angles in a staggered arrangement, and adjacent grating sheet groups are connected in a welding manner; the coalescence packing unit is formed by two grid plate groups with different inclination angles in a staggered arrangement mode, and adjacent grid plate groups are connected in a welding mode.

Optionally, the width of the grid pieces constituting the grid piece group is 5mm to 150 mm; the thickness of the grating pieces is 0.1 mm-2 mm; the distance between adjacent grating pieces is 5 mm-150 mm; preferably, the width of the grid pieces is 10 mm-80 mm, the thickness of the grid pieces is 0.3-1.5mm, and the distance between every two adjacent grid pieces is 10 mm-80 mm.

Optionally, the distance between the barrier strip and two adjacent grid pieces parallel to each other is equal, the width of the barrier strip is 1/3-1/2 of the distance between the grid pieces parallel to each other, and the barrier strip and the grid pieces are connected in a welding manner.

Optionally, in the extraction packing unit, the grid plates are provided with small holes at equal intervals, the diameter of each small hole is 2 mm-10 mm, the diameter of each small hole is not more than 1/3 of the width of the grid plate, and the central moment of adjacent small holes is 10 mm-100 mm.

Optionally, in the extraction packing unit, an arc piece is arranged above the small hole, and the width of the arc piece is from the diameter of the small hole to 2mm larger than the diameter of the small hole; the bending radius of the arc sheet is 1 mm-8 mm.

Optionally, the aperture ratio of the grid pieces is 3% -50%; preferably 4% to 15%.

Optionally, the extraction structured packing is made of stainless steel.

Optionally, the extraction column has an aspect ratio of (2-6): 1, the distance between the bottom of the extraction filler and the bottom of the tower is 0.5-5 m.

In the extraction structured packing filled in the packing extraction tower, the extraction packing unit is formed by staggered arrangement of two grid sheet groups with different inclination angles and is formed by circularly staggering a first grid sheet group and a second grid sheet group, wherein the included angle between the two adjacent grid sheet groups is 20-120 degrees, the included angle between the two adjacent grid sheet groups is preferably 90 degrees, and the included angle between the grid sheets of the first grid sheet group and the second grid sheet group and the horizontal plane is preferably 45 degrees.

A barrier strip is arranged on the plane where the first grid plate group is connected with the second grid plate group, and the plane where the barrier strip is located is respectively intersected with the grid pieces of the first grid plate group and the grid pieces of the second grid plate group; preferably, the plane of the barrier strip is perpendicular to the grating sheets of the first grating sheet group and the grating sheets of the second grating sheet group, and the barrier strip is arranged in parallel with one grating sheet group. The barrier strip is parallel to the first grating sheet group or the second grating sheet group, the distance between the barrier strip and two adjacent parallel grating sheets is equal, and the width of the barrier strip is 1/3-1/2 of the distance between the parallel grating sheets. The extraction structured packing is made of stainless steel, and the grid pieces and the barrier strips are connected in a welding mode.

In the preferred embodiment of the extraction of the regular packing on the grid plate of the extraction regular packing, the grid plate is provided with small holes, and more preferably, the small holes are provided with arc-shaped baffle plates. The structure with the small holes and the arc-shaped baffle plates can obviously increase the disturbance to the liquid flowing process, promote the surface updating effect in the liquid-liquid mass transfer process and improve the extraction efficiency.

The coalescence packing unit is formed by staggering two grating sheet groups with different inclination angles and is formed by circularly staggering a first grating sheet group and a second grating sheet group, wherein the included angle between the two adjacent grating sheet groups is 20-120 degrees, the included angle between the two adjacent grating sheet groups is preferably 90 degrees, and the included angle between the grating sheets of the first grating sheet group and the grating sheets of the second grating sheet group and the horizontal plane is preferably 45 degrees.

A barrier strip is arranged on the plane where the first grid plate group is connected with the second grid plate group, and the plane where the barrier strip is located is respectively intersected with the grid pieces of the first grid plate group and the grid pieces of the second grid plate group; preferably, the plane of the barrier strip is perpendicular to the grating sheets of the first grating sheet group and the grating sheets of the second grating sheet group, and the barrier strip is arranged in parallel with one grating sheet group. The barrier strip is parallel to the first grating sheet group or the second grating sheet group, the distance between the barrier strip and two adjacent parallel grating sheets is equal, and the width of the barrier strip is 1/3-1/2 of the distance between the parallel grating sheets. The coalescence regular packing is made of stainless steel and subjected to surface sand blasting treatment. The grating pieces are connected with each other and the barrier strips are connected with the grating pieces in a welding mode.

In the packing extraction tower provided by the invention, the extraction regular packing is formed by splicing two or more extraction packing units. The coalescence regular packing is formed by splicing two or more coalescence packing units. Two adjacent coalescing packing elements may be parallel or staggered by a certain angle. The coalescence structured packing is adapted to the shape of the reactor or the extraction tower.

The filling mode of the packing in the extraction tower is characterized in that the regular packing consists of packing units arranged in the vertical direction, and the upper layer of packing units rotates 30-150 degrees on the horizontal plane relative to the lower layer of packing units; more preferably 45 to 120 degrees.

Preferably, the extraction and coalescence structured packing further comprises a support plate arranged at the bottom of the extraction and coalescence structured packing and a cover plate arranged at the top of the extraction and coalescence structured packing, wherein the support plate and the cover plate are sieve plates, wire nets or cross beams.

In the second aspect, the invention provides an application method of a filler extraction tower, an extraction solvent enters the filler extraction tower from an extraction solvent inlet and moves upwards, a heavy raw material to be separated is introduced into the filler extraction tower from a raw material inlet and moves downwards, the two phases are in full contact mass transfer in an extraction section, a light component in the heavy raw material enters a solvent phase, and the rest components continue to move downwards and are discharged out of the extraction tower from a raffinate phase outlet; the solvent and light components pass through the coalescence section to coalesce and separate the entrained immiscible heavy feedstock, and the solvent leaving the coalescence section is discharged from the extraction column through an extract phase outlet.

In the third aspect, the invention provides a solvent deasphalting method, wherein any one of the filler extraction towers is adopted, a solvent is used as a continuous phase, enters the filler extraction tower from an extraction solvent inlet and moves upwards, residue oil is introduced into the filler extraction tower from a raw material inlet and moves downwards as a dispersed phase, the two phases are fully contacted and transferred in an extraction section, light components in the residue oil enter the solvent phase, residue oil droplets continuously move downwards, enter a residue oil space at the bottom of the tower and are discharged out of the extraction tower from a raffinate phase outlet; the solvent leaving the extraction section passes through the coalescence section to coalesce and separate the entrained dispersed phase droplets, and the solvent leaving the coalescence section is discharged out of the extraction column through an extract phase outlet; the solvent is selected from one or more of propane, butane and pentane.

Optionally, the material discharged from the extract phase outlet enters a solvent recovery tower to separate the deasphalted oil from the solvent, and the solvent obtained by separation returns to the extraction tower for recycling.

Optionally, the operating temperature of the packed extraction tower is 50-190 ℃, the operating pressure is 4.0-5.5 MPa, and the mass ratio of the solvent to the residual oil is (1.5-5): 1; the operating temperature of the solvent recovery tower is 180-260 ℃, and the operating pressure is 3.5-4.6 MPa.

The filler extraction column and the residual oil solvent deasphalting method provided by the invention are further described in detail in the following by combining the attached drawings.

FIG. 1 is a schematic diagram of the structure of one embodiment of a packed extraction column. As shown in fig. 1, the packed extraction column includes a shell 13, a raw material inlet 6 located in the middle of the shell 13, an extraction solvent inlet 7 located in the lower part, an overhead extraction phase outlet 8, a bottom raffinate phase outlet 9, and an extraction structured packing filled in the shell of the extraction column. The extraction section between the distributor at the raw material inlet 6 and the distributor at the extraction solvent inlet 7 is filled with extraction structured packing, and the structural schematic diagram of a preferred embodiment of the extraction structured packing is shown in the attached figure 2. Between the distributor of the raw material inlet 6 and the top of the extraction tower is a coalescence section 11, and preferably a coalescence regular packing is filled in the coalescence section 11, and the structural schematic diagram of a preferred embodiment of the coalescence regular packing is shown in figure 3.

The filler extraction tower provided by the invention is used for a residual oil deasphalting method, a solvent as a continuous phase enters the extraction tower from an extraction solvent inlet 7 distributor and moves upwards, and residual oil as a dispersed phase enters the extraction tower through a raw material inlet 6 distributor and moves downwards in the form of liquid drops. The two phases are substantially contacted for mass transfer in the extraction section 12 and the light components of the residuum enter the solvent phase. The residuum droplets leaving the extraction section continue to move downwardly through a liquid-liquid interface 10, enter the residuum space at the bottom of the column, and exit the extraction column through raffinate phase outlet 9. The solvent leaving the extractor section continues its upward movement, passes through the coalescer section 11 to coalesce the entrained dispersed phase droplets into larger droplets, and then moves downward to coalesce the formed dispersed phase droplets, thus minimizing entrainment of the dispersed phase droplets. The solvent leaving the coalescing section eventually exits the extraction column through extract phase outlet 8.

FIG. 2 is a schematic diagram of the structure of one embodiment of an extraction structured packing unit. In the embodiment shown in fig. 2, the extraction structured packing unit is composed of a plurality of grid plate groups which are staggered with each other, and the included angle between the adjacent grid plate groups is 90 °. In the first grating sheet group, the included angle between the grating sheets and the horizontal direction is 45 degrees, and in the second grating sheet group, the included angle between the grating sheets and the horizontal direction is 45 degrees. At least one row of small holes 3 are arranged on the grating sheet, and the aperture ratio is 3-50%. The diameter of the small hole 3 is 2 mm-10 mm, and the central moment of the adjacent small hole is 10 mm-100 mm. An arc piece 4 is arranged above the small hole 3, and the radius of the arc piece 4 is 1 mm-8 mm. The first grid plate group and the second grid plate group are crossed on the cross section, the barrier strips 5 are arranged, the barrier strips 5 are parallel to the grid plates of the first grid plate group, the barrier strips 5 are arranged between the grid plates of the two adjacent parallel grid plate groups, gaps are reserved between the barrier strips and the adjacent grid plates, and the width of each gap is 5% -45% of the distance between the adjacent grid plates.

FIG. 3 is a schematic diagram of one embodiment of a coalescing structured packing. As shown in fig. 3, the coalescence packing unit is composed of at least a first grating sheet group 1 and a second grating sheet group 2 which are obliquely staggered, the included angle of the adjacent grating sheet groups is 20-120 degrees, the grating sheet groups are composed of mutually parallel grating sheets, the included angle of the grating sheets and the horizontal plane is 0-90 degrees, a barrier strip 5 is arranged between the mutually staggered grating sheet groups, and the barrier strip is mutually parallel to the grating sheet group on one side; the coalescence packing unit is made of stainless steel, and the surface of the coalescence packing unit is subjected to sand blasting treatment. The structure of the coalescence regular packing and the structure of the extraction regular packing can be the same, and the size and the inclination angle of the coalescence regular packing and the extraction regular packing can be different.

FIG. 4 is a schematic diagram of an extractive separation-solvent recovery scheme. As shown in the attached figure 4, the residual oil enters the extraction tower from the raw material inlet 6 of the extraction tower and flows downwards, the solvent enters the extraction tower from the extraction solvent inlet 7 of the extraction tower and flows upwards, and contact mass transfer is carried out in the extraction section 12 so that light oil in the residual oil enters a solvent phase. The extract phase material flowing out from the extract phase outlet at the top of the extraction tower enters the solvent recovery tower 14. Compared with the extraction tower, the solvent recovery tower has lower operation pressure and higher operation temperature, so that the solubility of the solvent and the deasphalted oil is poor, and the separation of the solvent and the deasphalted oil is realized. The solvent discharged from the top of the solvent recovery tower returns to the extraction solvent inlet 7 of the extraction tower for recycling. And discharging deasphalted oil from the bottom of the solvent recovery tower for subsequent processing.

The structure of the packed extraction column and the effect of solvent deasphalting of the residuum provided by the present invention are further illustrated by the following examples, but the invention is not limited thereto.

Examples 1 to 4

Examples 1-4 thermal die experiments were used to demonstrate the effectiveness of the packed extraction column and the solvent deasphalting process provided by the present invention.

The extraction structured packing shown in the attached figure 2 is adopted, small holes are formed in the grating sheets of the grating sheet group, the hole opening rate is 5.7%, the diameter of each small hole is 4mm, the distance between every two adjacent holes is 20mm, the maximum width of each grating sheet is 10mm, the thickness of each grating sheet is 1mm, and the distance between every two adjacent grating sheets in the same layer is 10 mm. In the same layer, the width of the barrier strip is 4mm, the distance between the barrier strip and two adjacent grid sheets is 3mm, and the barrier strip is positioned on the cross section formed by the adjacent grid sheet groups. The width of the arc sheet at the upper part of the small hole is 4mm, and the radius is 4 mm.

The regular packing is applied to a solvent deasphalting extraction tower, the diameter of the extraction tower is 200mm, and the filling height of the extraction packing is 2400 mm. The extraction filler is positioned between a raw material inlet and an extraction solvent inlet of the extraction tower, the distance between the top of the filler and the raw material inlet is 30mm, and the distance between the bottom of the filler and the solvent inlet is 40 mm. In the extraction tower, a coalescence filler section is arranged above the raw material inlet, and the filling height of the coalescence filler is 2000 mm. The agglomerate packing has the same basic dimensions as the extraction packing, but the grid plates of the agglomerate packing have no openings and no curved baffles. The surface of the coalescing filler is sand blasted.

The raw material is vacuum residue (from Wuhan division of China petrochemical Co., Ltd., properties are shown in Table 1), the raw material flows in from the middle upper part of the tower, the extraction solvent is n-butane, the extraction solvent flows in from the middle lower part of the tower, and the mass ratio of the extraction solvent to the vacuum residue is 3: 1, the residence time of the vacuum residue in the extraction section is 20 min. The light phase and the heavy phase are in countercurrent flow contact in the tower. The rest of the extracted vacuum residue flows out from the bottom of the extraction tower, and the deasphalted oil extracted by solvent mixing flows out from the top of the extraction tower. The operating temperature of the extraction tower is 120 ℃, and the pressure is 4 MPa. And (3) after the solvent discharged from the top of the extraction tower and the deasphalted oil enter a solvent recovery tower to be separated, weighing the obtained deasphalted oil, wherein the yield of the deasphalted oil is 62.7% according to the ratio of the mass of the deasphalted oil to the feeding amount of the vacuum residue oil. The properties of the deasphalted oil and the deasphalted asphalt after passing through the solvent recovery column are shown in tables 1 and 2 (wherein the analysis method of the four components is NB/SH/T0509-2010).

TABLE 1

Example 2

The raw materials, experimental procedures and process conditions used were the same as those in example 1, and the structure of the extraction column used was substantially the same as that of the extraction column in example 1, except that no coalescing packing section was provided in the extraction column.

The experimental data show a deasphalted oil yield of 64.9% and the properties are shown in table 2.

Example 3

The raw materials, experimental procedures and process conditions used were the same as in example 1, and the extraction column structure was substantially the same as in example 1, except that the surfaces of the coalescing packing were not sand blasted. The experimental data show a yield of 63.4% deasphalted oil with the properties shown in table 2.

Example 4

The raw materials and process conditions adopted are the same as those of the embodiment 1, and the structure of the extraction tower is basically the same as that of the embodiment 1, except that the extraction filler is not provided with an arc-shaped baffle. The experimental data show that the yield of deasphalted oil is 56.7%, and the properties are shown in Table 2.

Comparative example 1

The raw materials and process conditions adopted are the same as those of the embodiment 1, the structure of the extraction tower is basically the same as that of the embodiment 1, the difference is that the extraction filler adopts the grid filler in the prior art, as shown in the attached figure 5, the structured packing is formed by splicing a plurality of rows of grid strip groups I16 and grid strip groups II 17 which are symmetrical to the grid strip groups I16 in the vertical direction, and is filled in the packed tower in a whole-building way, each row of grid strip group consists of a plurality of grid strips which are arranged in parallel in the same plane, each grid strip is punched with a guide hole, the opening directions of the guide holes in the grid strips which are parallel to each other are consistent, the aperture ratio of each guide hole in each grid strip is 10%, the diameter of each guide hole is 5mm, the distance between every two adjacent holes is 15mm, the maximum width of each grid sheet is 10mm, the thickness of each grid sheet is 1mm, and the distance between every two adjacent grid sheets in the same layer is 10 mm. The experimental data show that the yield of deasphalted oil is 54.2%, and the properties are shown in table 2.

TABLE 2

Examples 5-8 cold die experiments were used to demonstrate the throughput of packed extraction columns provided by the present invention.

Example 5

The structured packing shown in the attached figure 1 is adopted, small holes are formed in the grating sheets, the aperture ratio of the small holes is 5.7%, the diameter of each small hole is 8mm, the distance between every two adjacent holes is 20mm, the maximum width of each grating sheet is 30mm, the thickness of each grating sheet is 2mm, and the distance between every two adjacent grating sheets in the same layer is 30 mm. In the same layer, the width of the barrier strip is 10mm, the distance between the barrier strip and the adjacent 2 grid pieces is 10mm, and the barrier strip is positioned on one side of the cross section of the flow channel formed by the adjacent grid pieces. The width of the arc sheet 4 is 8mm, and the radius is 5 mm.

The regular packing is applied to a solvent deasphalting extraction tower, the diameter of the extraction tower is 150mm, and the packing height of the packing is 2000 mm.

The raw materials are commercial diesel oil and water, wherein the water flows in from the upper part of the top of a filler in the tower as a heavy phase, and the diesel oil flows in from the lower part of the bottom of the filler in the tower as a light phase. The mass ratio of diesel oil to water is 2.78: 1. the light phase and the heavy phase are in countercurrent flow contact in the tower. The contacted water flows out from the bottom of the extraction tower, and the diesel oil flows out from the top of the extraction tower.

The experimental results show that the two-phase flow ratio is maintainedContinuously increasing two-phase flow until the extraction tower is flooded, recording the flow data of the two phases, and obtaining the flooding flux of the extraction tower of 82m³/m²/h。

Example 6

Example 6 the same structure of extraction column, raw materials and process conditions as in example 5 were used, and the basic structure of the packed packing was the same as in example 5, except that the grid plates of the packing were perforated with small holes and arc-shaped baffle plates.

The experimental result shows that the flooding flux of the extraction tower is 80m³/m²/h。

Example 7

The same structure of extraction column, raw materials and process conditions as those of example 5 were used, and the basic structure of the packed material was also the same as that of example 5, except that the grid plates of the packed material were perforated with small holes but without arc-shaped baffle plates.

The experimental result shows that the flooding flux of the extraction tower is 90m³/m²/h。

Example 8

The same extraction column structure, feed and process conditions were used as in example 5. The packing filled was also substantially the same in structure as in example 5 except that the maximum width of the grid pieces was 15mm and the thickness was 1 mm. The distance between every two adjacent grid plates in the same layer is 15 mm. In the same layer, the width of the barrier strip is 5mm, the distance between the barrier strip and the adjacent 2 grid sheets is 5mm, and the barrier strip is positioned on one side of the cross section of the flow channel formed by the adjacent grid sheets. The width of the arc sheet 4 is 4mm, and the radius is 4 mm.

The experimental result shows that the flooding flux of the extraction tower is 95m³/m²/h。

Comparative example 2

The same extraction column and experimental system as in example 5 were used, with a commercially available corrugated packing having a height of 2000mm and a corrugated side length of 15mm being placed. The experimental result shows that the flooding flux of the extraction tower is 70m by adopting the corrugated packing³/m²/h。

Claims

1. A filler extraction tower is characterized by comprising a shell, a raw material inlet positioned in the middle of the shell, an extraction solvent inlet positioned at the lower part, a tower top extraction phase outlet, a tower bottom raffinate phase outlet and an extraction structured filler, wherein the extraction structured filler is filled in the shell of the extraction tower;

the extraction structured packing is formed by splicing one or more extraction packing units; the extraction filler unit is composed of at least two groups of obliquely staggered grid plate groups, the included angle of the adjacent grid plate groups is 20-120 degrees, the grid plate groups are composed of grid plates which are parallel to each other, the included angle between each grid plate and the horizontal plane is 0-90 degrees, and blocking strips are arranged on the cross sections between the adjacent grid plate groups and are parallel to the grid plate group on one side.

2. The packed extraction column of claim 1 wherein the extraction section between the feed inlet and the extraction solvent inlet is packed with said extraction structured packing and the coalescing section between the feed inlet and the top of the column is packed with coalescing structured packing.

3. The packed extraction column of claim 2, wherein the structured packing consists of one or more structured packing elements assembled together; the coalescence packing unit is composed of at least two groups of obliquely staggered grid plate groups, the included angle of the adjacent grid plate groups is 20-120 degrees, the grid plate groups are composed of mutually parallel grid plates, the included angle between each grid plate and the horizontal plane is 0-90 degrees, and barrier strips are arranged on the sections between the mutually staggered grid plate groups and are parallel to the grid plate group on one side; the coalescence packing unit is made of stainless steel, and the surface of the coalescence packing unit is subjected to sand blasting treatment.

4. The packing extraction tower according to any one of claims 1 to 3, wherein the extraction packing unit is formed by staggering two grid plate groups with different inclination angles, and adjacent grid plate groups are connected by welding; the coalescence packing unit is formed by two grid plate groups with different inclination angles in a staggered arrangement mode, and adjacent grid plate groups are connected in a welding mode.

5. The packed extraction column of claim 4, wherein the width of the grid segments constituting the grid segment group is 5mm to 150 mm; the thickness of the grating pieces is 0.1 mm-2 mm; the distance between adjacent grating pieces is 5 mm-150 mm;

preferably, the width of the grid pieces is 10 mm-80 mm, the thickness of the grid pieces is 0.3-1.5mm, and the distance between every two adjacent grid pieces is 10 mm-80 mm.

6. The packed extraction column as recited in claim 4, wherein the barrier is spaced apart from two adjacent parallel grid plates by an equal distance, the width of the barrier is 1/3-1/2 of the distance between the parallel grid plates, and the barrier is connected to the grid plates by welding.

7. The packed extraction column as defined in claim 4, wherein said packing elements are formed by opening said grid plates at equal intervals, said openings have a diameter of 2mm to 10mm, said openings have a diameter not greater than 1/3 of the width of the grid plates, and the center distance between adjacent openings is 10mm to 100 mm.

8. The packing extraction column according to claim 7, wherein in the extraction packing unit, an arc piece is arranged above the small hole, and the width of the arc piece is from the diameter of the small hole to 2mm larger than the diameter of the small hole; the radius of the arc sheet is 1 mm-8 mm.

9. The packed extraction column as recited in claim 7 or 8, wherein the grid plate has an open porosity of 3% to 50%; preferably 4% to 15%.

10. The packed extraction column of any of claims 1-3, wherein the extraction structured packing is stainless steel.

11. The packed extraction column according to any one of claims 1 to 10, wherein the extraction column has an aspect ratio of (2 to 6): 1, the distance between the bottom of the extraction filler and the bottom of the tower is 0.5-5 m.

12. The method of using a packed extraction column as claimed in any one of claims 1 to 11, wherein the extraction solvent is introduced into the packed extraction column through the extraction solvent inlet and then moves upward, the heavy feedstock to be separated is introduced into the packed extraction column through the feedstock inlet and then moves downward, the two phases are in full contact with each other in the extraction section for mass transfer, the light components in the heavy feedstock enter the solvent phase, and the remaining components continue to move downward and exit the extraction column through the raffinate outlet; the solvent and light components pass through the coalescence section to enable the carried immiscible heavy raw material to be coalesced and separated, and the solvent leaving the coalescence section is discharged out of the extraction tower from an extraction phase outlet.

13. A method for removing asphalt from residual oil by solvent, which adopts the filler extraction tower as claimed in any one of claims 1 to 11, the solvent as continuous phase moves upwards after entering the filler extraction tower from the extraction solvent inlet, the residual oil is introduced into the filler extraction tower from the raw material inlet and moves downwards as dispersed phase, the two phases are fully contacted and transferred in the extraction section, the light component in the residual oil enters the solvent phase, the residual oil liquid drops continuously move downwards to enter the residual oil space at the bottom of the tower and are discharged out of the extraction tower from the raffinate phase outlet; the solvent leaving the extraction section passes through the coalescence section to coalesce and separate the entrained dispersed phase droplets, and the solvent leaving the coalescence section is discharged out of the extraction column through an extract phase outlet; the solvent is selected from one or more of propane, butane and pentane.

Preferably, the material discharged from the extraction phase outlet enters a solvent recovery tower to separate the deasphalted oil from the solvent, and the solvent obtained by separation returns to the extraction tower for recycling.

14. The solvent deasphalting method for residual oil according to claim 13, characterized in that the operating temperature of the filler extraction tower is 50 to 190 ℃, the operating pressure is 4.0 to 5.5MPa, and the mass ratio of the solvent to the residual oil is (1.5 to 5): 1; the operating temperature of the solvent recovery tower is 180-260 ℃, and the operating pressure is 3.5-4.6 MPa.