阅读说明：本技术 油浆过滤系统及其油浆过滤方法 (Oil slurry filtering system and oil slurry filtering method thereof ) 是由 胡志海 韩勇 牛传峰 王灵萍 邵志才 陈坦 邓中活 肖锦山 戴立顺 李莎莎 黄海 于 2019-02-20 设计创作，主要内容包括：油浆过滤系统和油浆过滤方法,包括过滤单元和助滤剂缓冲罐,所述过滤单元中设置至少一个过滤器,以及分别与每个过滤器连通的油浆入口管线、滤后油出口管线、滤渣排出管线,助滤剂缓冲罐的出口与过滤器的油浆入口连通,所述过滤器中设置柔性过滤材质的无针孔滤袋。该油浆过滤方法中,油浆通过与过滤器连通的油浆入口管线进入过滤器中进行过滤,滤后油从滤后油出口管线抽出。采用本发明提供的油浆过滤系统和过滤方法,油浆过滤过程的长期稳定运行,解决了过滤材质易被高黏性胶质杂质堵塞、再生效率差和去除效率低的问题。(The oil slurry filtering system comprises a filtering unit and a filter aid buffer tank, wherein at least one filter, an oil slurry inlet pipeline, a filtered oil outlet pipeline and a filter residue discharge pipeline are arranged in the filtering unit, the oil slurry inlet pipeline, the filtered oil outlet pipeline and the filter residue discharge pipeline are respectively communicated with each filter, an outlet of the filter aid buffer tank is communicated with an oil slurry inlet of each filter, and a non-pinhole filter bag made of flexible filtering materials is arranged in each filter. In the oil slurry filtering method, oil slurry enters a filter for filtering through an oil slurry inlet pipeline communicated with the filter, and filtered oil is pumped out from a filtered oil outlet pipeline. By adopting the oil slurry filtering system and the filtering method provided by the invention, the oil slurry filtering process can run stably for a long time, and the problems that the filtering material is easy to be blocked by high-viscosity colloid impurities, the regeneration efficiency is poor and the removal efficiency is low are solved.)

1. An oil slurry filtering system comprises a filtering unit and a filter aid buffer tank, wherein at least one filter, an oil slurry inlet pipeline, a filtered oil outlet pipeline and a filter residue discharge pipeline are arranged in the filtering unit and are respectively communicated with each filter, and an outlet of the filter aid buffer tank is communicated with an oil slurry inlet of each filter;

a non-pinhole filter bag made of flexible filter materials is arranged in the filter; the flexible filtering material is selected from one or more of polypropylene, polyethylene, nylon, terylene, polyphenylene sulfide, polyimide, polytetrafluoroethylene, aramid fiber, polyurethane, glass fiber and vinylon, or a material formed by compounding more than any two of the above materials;

the filtering precision of the flexible filtering material is 3-25 microns; the porosity of the flexible filtering material is 85% -98%, and the gram weight is 300-1000 g/m²。

2. The filtration system of claim 1, wherein the flexible filtration material has a thickness of 0.5 to 3.0mm, a warp break strength of 1000N/5cm to 9000N/5cm, and a weft break strength of 1000N/5cm to 11000N/5 cm.

3. The filtration system of claim 1, wherein the filter has a slurry inlet at a lower portion of the filter, a filtered oil outlet at an upper portion of the filter, and a residue outlet at a bottom portion of the filter.

4. The filtration system according to claim 1, wherein the filter aid buffer tank is provided with a stirring member; the stirring component is preferably a rotatable blade stirring component.

5. The filtration system of claim 1, wherein the inlet of the filter aid surge tank is in communication with the filtered oil outlet line of the filter.

6. The filtration system according to claim 1 or 5, wherein the filter aid buffer tank is filled with a filter aid and a mixed medium, the filter aid is one or more selected from the group consisting of diatomaceous earth, cellulose, perlite, filter residue obtained by a filter, and a spent catalytic cracking catalyst, and the mixed medium is liquid hydrocarbon.

7. A filtration system according to claim 1, wherein the filter is provided with a purge medium inlet.

8. A filtration system according to claim 1, wherein the filtration system comprises a purge media buffer tank, the outlet of the purge media buffer tank being in communication with the filter purge media inlet.

9. A method of filtering a slurry comprising:

(1) the filter aid and the mixed medium are fully mixed in a filter aid buffer tank, and then are added into a filter through an oil slurry inlet pipeline communicated with the filter, and when a filter cake is formed on the surface of a non-pinhole filter bag made of flexible filter materials, the addition of the filter aid is stopped;

(2) the oil slurry enters the filter through an oil slurry inlet pipeline communicated with the filter for filtering, a non-pinhole filter bag made of flexible filtering materials is arranged in the filter, filtered oil is pumped out from a filtered oil outlet pipeline, and the oil slurry is liquid hydrocarbon with particulate impurities.

10. The process according to claim 9, characterized in that the filter aid forming cake in step (1) has a thickness of from 0.1mm to 10 mm.

11. The method according to claim 9, wherein the temperature of the filter in step (1) is 30 to 200 ℃, preferably 50 to 180 ℃;

the temperature of the filter in the step (2) is 30-250 ℃, preferably 50-240 ℃, and further preferably 60-180 ℃.

12. The method according to claim 9, wherein the pressure difference of the filter in the step (1) is 0.01 to 0.07 MPa; the pressure difference of the filter in the step (2) in use is 0.01-0.5 MPa.

13. The method according to claim 9, characterized in that the filter aid buffer tank is filled with a filter aid and a mixing medium, the filter aid is one or more selected from the group consisting of diatomaceous earth, cellulose, perlite, filter residue obtained from a filter, and spent catalytic cracking catalyst, and the mixing medium is a liquid hydrocarbon, preferably a filtered oil.

14. The process of claim 9, wherein the slurry oil is a catalytic cracking slurry oil and/or coal tar.

15. The method of claim 9, wherein the used filter is back-purged with a purge medium.

16. A method according to claim 9, characterized in that the purging medium is an inert gas and/or a flushing oil.

17. The method of claim 16, wherein the flushing oil is filtered oil.

Technical Field

The invention relates to an oil slurry filtering system and an oil slurry filtering method.

Background

Catalytic cracking is an important process technology for producing gasoline and diesel oil by converting heavy oil into light oil, is one of the most important and widely applied technologies in the field of oil refining at present, but produces a byproduct of slurry oil by catalytic cracking, particularly, hydrogenated residual oil or wax oil mixed with the hydrogenated residual oil is mostly adopted as a raw material in the present catalytic cracking process, the yield of the slurry oil is higher, generally about 5%, and the yield is even 8%. The oil slurry is rich in polycyclic aromatic hydrocarbon which can be used as raw materials for producing ship fuel or carbon black, carbon fiber and the like, but the oil slurry contains about 1-6 g/L of catalytic cracking catalyst particles, so that the requirement of the raw materials for producing the ship fuel or the carbon black, the carbon fiber and the like cannot be met, and the utilization value is low at present.

In order to improve the utilization value of the oil slurry, the solid particles in the oil slurry must be removed firstly. There are several methods for removing solid particles, such as settling, flocculation, centrifugation, etc., but these methods have too low removal efficiency. Filtration is a good method for removing solid particles in oil slurry, but a multi-stage filtration method is adopted to improve the filtration precision.

CN102002385A discloses a device and a method for separating residues from catalytic cracking slurry oil, wherein the device comprises at least two filter groups, each filter group comprises a prefilter and a fine filter, the prefilter is a wedge-shaped metal winding wire filter element, the filtering precision is 2-10 microns, and the fine filter is an asymmetric metal powder sintering filter element, the precision is 0.2-1.0 micron.

CN103865571A describes a method for removing solid particles from heavy oil, wherein the filtering system comprises at least one prefilter and at least two fine filters, the precision of the filter element of the fine filter is better than that of the prefilter, and the prefilter is connected with the fine filter in series. The method for re-forming the filter cake on the fresh or back-flushed fine filter is to form a filter cake on the fine filter by using the filtrate filtered by the pre-filter, and prevent the liquid to be filtered from directly forming the filter cake on the fine filter.

Disclosure of Invention

The invention aims to provide an oil slurry filtering system and an oil slurry filtering method thereof, so as to solve the problems of complex oil slurry filtering process, short operation period, high cost and the like in the prior art.

The invention provides an oil slurry filtering system which comprises a filtering unit and a filter aid buffer tank, wherein at least one filter, an oil slurry inlet pipeline, a filtered oil outlet pipeline and a filter residue discharge pipeline are arranged in the filtering unit, and are respectively communicated with each filter;

a non-pinhole filter bag made of flexible filter materials is arranged in the filter; the flexible filtering material is selected from one or more of polypropylene, polyethylene, chinlon, terylene, polyphenylene sulfide, polyimide, polytetrafluoroethylene, aramid fiber, polyurethane, glass fiber and vinylon, or a composite material of any two or more of the above materials;

the filtering precision of the flexible filtering material is 3-25 microns; the porosity of the flexible filtering material is 85% -98%, and the gram weight is 300-1000 g/m²。

In order to achieve better oil slurry filtering effect and prolong the service life of the filter, the thickness of the flexible filtering material is preferably 0.5-3.0 m, the warp-wise breaking strength is 1000N/5 cm-9000N/5 cm, and the weft-wise breaking strength is 1000N/5 cm-11000N/5 cm.

The flexible filter material of the invention is a single layer or a plurality of layers. When a plurality of layers are used, there is no limitation in the number of layers and the arrangement between the layers.

The invention adopts the non-pinhole filter bag made of flexible filtering material in the filter, and the preferable flexible filtering material has the characteristics of strong chemical stability, good wear resistance and fatigue resistance, strong interception on particles, high filtering precision and good material strength.

Preferably, the non-pinhole filter bag made of the flexible filter material is prepared by adopting a sewing process, and the sewing holes are sealed by using an acid sealant material.

In a preferable case, the lower part of the filter is provided with an oil slurry inlet, the upper part of the filter is provided with a filtered oil outlet, and the bottom of the filter is provided with a filter residue outlet.

Preferably, the filter aid buffer tank is provided with a stirring member. The stirring member is preferably a rotatable blade member. The specific form of the stirring means is not subject to any restriction, and any means which enables a sufficiently homogeneous mixing of the filter aid and the mixing medium is within the scope of the present invention.

In a preferable case, a filter aid and a mixing medium are filled in a filter aid buffer tank, wherein the filter aid is one or more selected from diatomite, cellulose, perlite, filter residue obtained by a filter and a waste catalytic cracking catalyst. The mixed medium is liquid hydrocarbon, and is further preferably filtered oil.

In one embodiment of the invention, the inlet of the filter aid buffer tank is in communication with the filtered oil outlet line of the filter.

In a preferred aspect, the filter of the present invention is provided with a purge medium inlet.

In one preferred embodiment of the invention, a purge medium buffer tank is included in the filtration system, and an outlet of the purge medium buffer tank is communicated with the filter purge medium inlet.

In the present invention, one filter may be provided in the filter unit, or two or more filters may be provided. When a plurality of filters are provided, the present invention is not limited to any connection manner. The filters can be arranged in parallel or in series, or used in a switching way, or used in parallel and series simultaneously. When a plurality of filters are provided, a plurality of filters having the same filtering accuracy may be used, or a plurality of filters having different filtering accuracies may be used.

According to the oil slurry filtering system provided by the invention, the non-pinhole filter bag made of the flexible filtering material is adopted in the filter, and the preferable flexible filtering material has the characteristics of strong interception on particles, high filtering precision and good material strength. Due to the adoption of the flexible filtering material, the defect that the hard filtering material is easily blocked by fine solid particles is overcome, the filtering efficiency is improved, and the operation period of the slurry filtering system is prolonged. In addition, the oil slurry filtering system provided by the invention has the characteristics of convenience in slag unloading, good back flushing effect and good regeneration performance of filtering materials.

The invention also provides an oil slurry filtering method, which adopts any one of the oil slurry filtering systems, and comprises the following steps:

(1) the filter aid and the mixed medium are fully mixed in a filter aid buffer tank, and then are added into a filter through an oil slurry inlet pipeline communicated with the filter, and when a filter cake is formed on the surface of a non-pinhole filter bag made of flexible filter materials, the addition of the filter aid is stopped;

(2) the oil slurry enters the filter through an oil slurry inlet pipeline communicated with the filter for filtering, a non-pinhole filter bag made of flexible filtering materials is arranged in the filter, filtered oil is pumped out from a filtered oil outlet pipeline, and the oil slurry is liquid hydrocarbon with particulate impurities. Preferably, the oil slurry is catalytic cracking oil slurry and/or coal tar.

Preferably, the thickness of the filter aid forming filter cake in the step (1) is 0.1-10 mm.

Preferably, the temperature of the filter in the step (1) is 30-250 ℃, and further preferably 50-180 ℃; the temperature of the filter in the step (2) is 30-250 ℃, more preferably 50-240 ℃, and further preferably 60-180 ℃.

Preferably, the pressure difference of the filter in the step (1) is 0.01-0.07 MPa; the pressure difference of the filter in the step (2) in use is 0.01-0.5 MPa.

In a preferred embodiment of the invention, a filter aid and a mixing medium are filled in a filter aid buffer tank, and the filter aid is preferably one or more selected from diatomite, cellulose, perlite, filter residue obtained by a filter and a waste catalytic cracking catalyst. Preferably, the mixed medium is a liquid hydrocarbon, and more preferably is a filtered oil.

In one preferred embodiment of the invention, the used filter is back-purged with a purge medium.

Preferably, the purging medium is an inert gas and/or a flushing oil. The inert gas is a gas which does not react with oil slurry and particles in the filtering system, and is preferably nitrogen. In some cases, fuel gas may also be selected. The flushing oil is preferably filtered oil.

When a filter is provided in the filtering unit of the slurry filtering system, it is preferable to operate in a manner that the filtering mode and the purging mode are alternately performed.

When the filtering unit of the slurry filtering system is provided with a plurality of filters, the operation is preferably performed by alternately switching the on-line filter and the standby filter. When the pressure differential across the in-line filter reaches or exceeds the pressure differential set point, the spare filter can be switched into the filtration system and the in-line filter can be switched out of the filtration system, back-purged, deslagged and filter-aided to form a filter cake. Filter residue discharged from the liquid mixture has good fluidity and can be directly returned to the process for reuse according to the process requirements; the filter cake can also be stabilized at the filter, dried and discharged directly from the filter system in the form of a completely solidified filter residue.

Compared with the prior art, the oil slurry filtering system and the filtering method provided by the invention can realize long-term stable operation of high-concentration colloid-containing viscous catalyst materials, and solve the problems that the filtering material is easy to be blocked by high-viscosity colloid impurities, the regeneration efficiency is poor and the removal efficiency is low. And the slag discharging mode is flexible, and the problem of environmental pollution caused by organic materials of the catalyst is effectively solved.

Drawings

FIG. 1 is a schematic diagram of one embodiment of a slurry filtration system provided by the present invention.

FIG. 2 is a schematic diagram of another embodiment of the slurry filtration system provided by the present invention.

Detailed Description

The invention will be further described with reference to the accompanying drawings, but the invention is not limited thereto.

Fig. 1 is a schematic diagram of a single filter of the slurry filtering system provided by the present invention, and as shown in fig. 1, the present invention provides a slurry filtering system comprising a filtering unit and a filter aid buffer tank 6, wherein the filtering unit is provided with the filter 1, a slurry inlet pipeline 3 communicated with the filter 1, a filtered oil outlet pipeline 4, and a residue discharge pipeline 5, and an outlet of the filter aid buffer tank 6 is communicated with a slurry inlet pipeline 8 of the filter. A non-pinhole filter bag 2 made of flexible filter material is arranged in the filter; the flexible filtering material is selected from one or more of polypropylene, polyethylene, chinlon, terylene, polyphenylene sulfide, polyimide, polytetrafluoroethylene, aramid fiber, polyurethane and glass fiber, or a composite material of any two or more of the above materials. A purge medium inlet is provided at the top and upper part of the filter 1 and communicates with a purge medium inlet line 10. The inlet of the filter aid buffer tank 6 is communicated with an inlet pipeline 7, and the inlet of the filter aid buffer tank 6 is communicated with a filtered oil outlet pipeline of the filter through a pipeline 9.

FIG. 2 is a schematic diagram of the slurry filtering system provided with two filters, and as shown in FIG. 2, the slurry filtering system provided by the present invention comprises a filtering unit and a filter aid buffer tank 16, wherein the filtering unit is provided with a filter 1, a filter 3, a slurry inlet pipeline 5 communicated with the filter 1, a filtered oil outlet pipeline 7 and a filter residue discharge pipeline 9; an oil slurry inlet line 6 communicating with the filter 3, a filtered oil outlet line 8, and a residue discharge line 10. A non-pinhole filter bag 2 made of flexible filter material is arranged in the filter 1; a non-pinhole filter bag 4 made of flexible filtering materials is arranged in the filter 3; the flexible filtering material is selected from one or more of polypropylene, polyethylene, chinlon, terylene, polyphenylene sulfide, polyimide, polytetrafluoroethylene, aramid fiber, polyurethane and glass fiber, or a composite material of any two or more of the above materials. A purging medium inlet is arranged at the top of the filter 1 and is communicated with a purging medium inlet pipeline 11; the upper part of the filter 1 is provided with a purging medium inlet and is in communication with a purging medium inlet line 13. A purging medium inlet is arranged at the top of the filter 3 and is communicated with a purging medium inlet pipeline 12; the upper part of the filter 3 is provided with a purging medium inlet and communicates with a purging medium inlet line 14. A communication line 15 is provided between the filtered oil outlet of the filter 1 and the slurry inlet of the filter 3. The outlet of the filter aid buffer tank 16 is connected to the slurry inlets of the filters 1 and 3 via a line 18. The inlet of the filter aid buffer tank 16 is communicated with an inlet line 17, and the inlet of the filter aid buffer tank 16 is communicated with the filtered oil outlet lines of the filters 1 and 3 through a line 19.

When the filtering system shown in fig. 2 is used for filtering, the filter 1 and the filter 3 may be used in parallel, in series, or in a switched manner. When the filter 1 is switched to be used and on-line filtration is carried out, the filter 3 is simultaneously subjected to back purging, filter cakes are formed by using filter aids or the filter is in a standby state; or the filter 3 is on-line, the filter 1 is back-purged at the same time, and a filter cake is formed with a filter aid or is in a standby state.

The present invention is further illustrated by the following examples, which are not intended to limit the invention in any way.