CN110747006A

CN110747006A - Method for removing solid impurities in catalytic oil slurry

Info

Publication number: CN110747006A
Application number: CN201911179656.3A
Authority: CN
Inventors: 杨根长
Original assignee: Beijing Obos Engineering Technology Co Ltd
Current assignee: Beijing Obos Engineering Technology Co Ltd
Priority date: 2019-11-27
Filing date: 2019-11-27
Publication date: 2020-02-04

Abstract

The invention provides a method for removing solid impurities from catalytic slurry oil, which is provided with a solvent-oil mixing unit, a centrifugal deasphalting unit, a light oil slurry filtering unit, a light oil slurry desolventizing unit and a heavy oil slurry desolventizing unit. The catalytic oil slurry and the solvent are fully mixed, and asphaltene in the oil slurry is removed through centrifugal separation according to different solubilities of the solvent on various components of the oil slurry, so that the influence of the asphaltene on the filtration of the oil slurry is reduced, the reliability of the filtration of the oil slurry is improved, and the long-period stable operation of an oil slurry filtration system is ensured. The solvent is recycled and recycled through the light and heavy oil slurry desolventizing unit, so that the solvent consumption is reduced.

Description

Method for removing solid impurities in catalytic oil slurry

Technical Field

The invention relates to the field of petroleum refining and chemical industry, in particular to a method for removing solid catalyst powder in catalytic slurry oil produced by a catalytic cracking device.

Background

With the rapid increase of the world economy, the oil refining technology is developing towards the heavy oil lightening and clean gasoline fuel production and the high yield of low carbon olefins, the catalytic cracking unit is used as a core unit for processing heavy oil, the processing capacity is continuously improved, and the yield of oil slurry is increased. However, with the deterioration trend of catalytic raw materials and the application of the process of catalyzing and blending residual oil, the external throwing amount of the catalytic slurry oil is increased.

The catalytic slurry oil is used as a byproduct generated by a catalytic cracking device of a refinery, has high aromatic content and is a precious petrochemical raw material, but the slurry oil contains catalyst particles with higher concentration (the concentration is generally 3000-7000 ppm) and contains a certain amount of asphaltene, so that the catalyst particles cannot be effectively utilized. The oil slurry after solid powder removal has wide application: can be used as raw material for producing needle coke, blending group for producing propane deasphalting reinforcer or asphalt modifier and marine fuel oil, and for producing rubber softener and filling oil.

Therefore, to fully utilize the slurry oil, the catalytic slurry oil must first be stripped to remove the catalyst fines. The conventional oil slurry solid removal method mainly comprises a filtration separation method, a sedimentation method, a distillation method and the like. The filtering method adopts a method of limiting solid particles to pass through gaps/pore channels of the filter element to remove catalyst powder, but asphaltene in catalytic slurry oil blocks the filter element, so that the filter element cannot be regenerated by back flushing, and a filtering facility cannot run for a long period. The settling method, which increases the settling speed and the removal degree of the catalyst fine powder by adding a settling agent into the oil slurry, has simple operation and low investment, but is difficult to remove the catalyst particles with the particle size of less than 20 mu m, has longer separation time and low efficiency. The catalytic oil slurry is subjected to reduced pressure distillation by a distillation method, the viscosity of light distillate oil obtained by distillation separation is greatly reduced, the ash content is close to zero, almost all catalyst powder, colloid and asphaltene are retained in heavy distillate oil, the catalytic oil is heated by a heating furnace in the distillation method, a distillation tower is a vacuum tower, a vacuumizing facility is required to be arranged, and the investment is large; in addition, the oil slurry exchanges heat with all side lines of the distillation tower, a plurality of heat exchangers are provided, and catalyst particles in the oil slurry can deposit and scale in the heat exchangers, so that the heat exchange efficiency is influenced.

Disclosure of Invention

The invention provides a method for removing solid impurities in catalytic slurry oil by optimally setting various processes according to the property characteristics of the catalytic slurry oil, which has low operation cost, can treat the catalytic slurry oil continuously with large treatment capacity for a long period and effectively remove asphaltene and catalyst powder in the catalytic slurry oil. The technical scheme of the invention is as follows:

the device is provided with a mixture oil mixing unit, a centrifugal deasphalting unit, a light oil slurry filtering unit, a light oil slurry desolventizing unit and a heavy oil slurry desolventizing unit.

The catalytic oil slurry and the solvent are fully mixed by a solvent-oil mixing unit, the light oil slurry is dissolved by the solvent, and the asphaltene and the heavy oil slurry are not dissolved to form light-heavy two-phase mixed oil; separating the mixed oil into mixed oil of light oil slurry and a solvent and mixed oil of heavy oil slurry and the solvent through a centrifugal deasphalting unit; separating the heavy oil slurry and the solvent from the mixed oil of the heavy oil slurry and the solvent by a heavy oil slurry desolventizing unit; filtering the mixed oil of the light oil slurry and the solvent by a light oil slurry filtering unit, removing solid impurities in the mixed oil, and separating the light oil slurry and the solvent by a light oil slurry desolventizing unit; the solvent obtained by the light oil slurry desolventizing unit and the heavy oil slurry desolventizing unit is recycled before the solvent-oil mixing unit, the light oil slurry with the solid impurities removed is sent to a downstream processing device or blended bunker fuel oil, and the heavy oil slurry with the solid impurities removed is sent to blended asphalt or sent to a coking device for processing.

The solvent is single alkane of C5-C8 or a mixture of several alkanes, the mass mixing ratio of the solvent to the catalytic slurry oil is 1: 2-2: 1, centrifugal deasphalting is to realize centrifugal separation of light and heavy phases through a cyclone or a centrifugal machine to remove most of asphaltene in the slurry oil, and a light slurry oil filtering unit adopts the forms of filter element mechanical filtering, membrane filtering and electrostatic adsorption filtering to carry out filtering. The light oil slurry desolventizing unit and the heavy oil slurry desolventizing unit realize the separation of oil slurry and solvent in the modes of heating steam stripping, distillation and gravity settling.

The technical scheme of the invention has the beneficial effects that:

in the centrifugal deasphalting unit, the catalyst powder can be enriched in the heavy phase mixed oil, the content of the catalyst powder in the light phase mixed oil is relatively low, the filtering difficulty is reduced, and the coke cleaning or backwashing frequency of the filter is greatly reduced.

The light mixed oil does not contain asphaltene basically, and the problems of filter element coking and long-period operation incapability exist when the light mixed oil or light oil slurry obtained by separating the light mixed oil is filtered.

The method has low operation temperature and low operation pressure, and is favorable for safe production.

The method can ensure the solid removal effect of the light oil slurry, the light oil slurry does not contain asphaltene, conditions are created for the effective utilization of the oil slurry, and the method has high yield of the light oil slurry and can be used for long-period, stable and large-treatment-capacity production and operation.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of exemplary embodiments thereof, which is to be read in connection with the accompanying fig. 1.

FIG. 1 is a schematic flow diagram of a method for removing solid impurities from catalytic slurry oil according to the present invention.

The constituent units or devices:

a mixture oil mixing unit B centrifugal deasphalting unit

C light oil slurry filtering unit D light oil slurry desolventizing unit

E heavy oil slurry desolventizing unit

Logistics:

1 catalytic slurry oil 2 blend oil

3 mixed oil of light oil slurry and solvent 4 mixed oil of heavy oil slurry and solvent

5 filtered light mixed oil 6 catalyst powder

7 light oil slurry and 8 heavy oil slurry

9 solvent

Detailed Description

Preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be embodied in various forms and should not be limited to the embodiments set forth herein.

Examples

A method for removing solid impurities in catalytic oil slurry is shown in figure 1, and specifically comprises the following steps:

and (3) allowing the catalytic slurry oil 1 and the solvent 9 to enter a mixture oil mixing unit A, and fully mixing to obtain mixed oil 2.

The mixed oil 2 passes through a centrifugal deasphalting unit B, and mixed oil 3 of light oil slurry and solvent and mixed oil 4 of heavy oil slurry and solvent are separated.

The mixed oil 4 of the heavy oil slurry and the solvent is separated into the heavy oil slurry 8 and the solvent 9 through a heavy oil slurry desolventizing unit E.

And filtering the mixed oil 3 of the light oil slurry and the solvent by a light oil slurry filtering unit C to remove catalyst powder 6 to obtain filtered light mixed oil 5.

And separating the light mixed oil 5 after filtration into light oil slurry desolventizing unit D to obtain light oil slurry 7 and a solvent 9.

And the solvent 9 obtained by separating the light oil slurry desolventizing unit D and the heavy oil slurry desolventizing unit D is continuously mixed with the catalytic oil slurry 1 for recycling.

In this embodiment:

the solvent 9 adopts n-hexane, and the mass mixing ratio of the solvent 9 to the catalytic slurry oil 1 is 1.5: 1.

The catalyst oil mixing unit a mixes the catalyst oil slurry 1 and the solvent 9 by a static mixer.

The centrifugal deasphalting unit B adopts a cyclone to separate the mixed oil 3 of the light oil slurry and the solvent and the mixed oil 4 of the heavy oil slurry and the solvent, so that most of asphaltene is separated into the mixed oil 4 of the heavy oil slurry and the solvent, and the filtering difficulty of the mixed oil 3 of the light oil slurry and the solvent is reduced.

The light slurry filtering unit C filters the mixed oil 3 of the light slurry and the solvent by using a filter using a johnson mesh as a filter element. And the light oil slurry desolventizing unit D and the heavy oil slurry desolventizing unit E adopt a distillation method to recover the solvent.

Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for removing solid impurities in catalytic oil slurry is characterized by comprising the following steps:

the method comprises the steps of setting a solvent-oil mixing unit, a centrifugal deasphalting unit, a light oil slurry filtering unit, a light oil slurry desolventizing unit and a heavy oil slurry desolventizing unit;

2. The method for removing solid impurities from catalytic slurry oil as claimed in claim 1, wherein the solvent is a single alkane or a mixture of several alkanes containing C5-C8.

3. The method for removing solid impurities from catalytic slurry oil according to claim 1, wherein the mass mixing ratio of the solvent to the catalytic slurry oil is 1: 2-2: 1.

4. The method of claim 1, wherein the centrifugal deasphalting is to remove most of the asphaltenes from the slurry by centrifuging the light and heavy phases through a cyclone or centrifuge.

5. The method for removing solid impurities from catalytic slurry oil of claim 1, wherein the slurry oil filtering unit is a filter unit adopting mechanical filtration, membrane filtration and electrostatic adsorption filtration.

6. The method for removing solid impurities from catalytic slurry oil according to claim 1, wherein the light oil slurry desolventizing unit and the heavy oil slurry desolventizing unit are used for separating the slurry oil from the solvent by means of steam stripping, distillation and gravity settling.