CN219174448U - Crude oil distillation and catalytic cracking combined crude oil processing device - Google Patents

Abstract

The utility model relates to a device for processing crude oil by combining crude oil distillation and catalytic cracking. The device for processing crude oil by combining crude oil distillation and catalytic cracking comprises: the method comprises the steps of a crude oil atmospheric distillation tower, an atmospheric residue vacuum flash tower, a catalytic cracking reactor and a catalytic cracking fractionating tower, wherein the residue at the bottom of the vacuum flash tower enters the bottom of the catalytic cracking fractionating tower to wash catalyst powder in reaction oil gas from the catalytic cracking reactor, and then the residue at the bottom of the fractionating tower, the distillate of the vacuum flash tower containing the catalyst powder and the atmospheric distillation residue which does not enter the vacuum flash tower enter the catalytic cracking reactor together or pairwise or singly enter the catalytic cracking reactor to carry out catalytic cracking reaction. In the utility model, the residual oil at the bottom of the vacuum flash tower is adopted to elute catalyst powder in the catalytic cracking reaction oil gas, so that the ash content in the high aromatic hydrocarbon oil extracted by the fractionating tower is extremely low, and the high aromatic degree of the high aromatic hydrocarbon oil is ensured, thereby meeting the requirements of raw materials of products such as needle coke, carbon fiber and the like.

Description

Crude oil distillation and catalytic cracking combined crude oil processing device

Technical Field

The utility model relates to the field of crude oil processing, in particular to a device for processing crude oil by combining crude oil distillation and catalytic cracking.

Background

Crude oil distillation and catalytic cracking combined processing of crude oil are the traditional most common petroleum refining processes. The earliest technology is that the vacuum distillation distillate oil after the atmospheric and vacuum distillation of crude oil enters a catalytic cracking device to be cracked to generate diesel oil, gasoline, liquefied gas and dry gas. With the heavy weight of crude oil and the reduction of resources, vacuum distillation residual oil is also used as a catalytic cracking raw material, so that the vacuum distillation distillate oil blending slag catalytic cracking process is developed. Considering the unreasonable technical economy of the process of entering the catalytic cracking after the re-mixing of the distillate oil and the vacuum residue after the vacuum distillation, the process of directly entering the catalytic cracking of the crude oil atmospheric distillation residue is developed, and the process is the most popular crude oil processing process at present.

In terms of the current industrial processing technology, products produced by catalytic cracking are diesel oil, gasoline, liquefied gas, dry gas and low-value slurry oil, and the slurry oil contains a large amount of solid matters (2-6 g/L) such as catalyst powder. If the solid matters such as catalyst powder in slurry oil are removed, the high aromatic hydrocarbon oil can be used as raw materials for producing carbonaceous materials such as needle coke, carbon fiber and carbon black, fine chemical products such as rubber softeners and fillers, petroleum aromatic hydrocarbon plasticizers, heat conducting oil and petroleum sulfonate surfactants and the like and fuel oil blending components, but the solid content is required to be less than 500 mug/g, and even less than 20 mug/g (Chen Junwu and other main editions of catalytic cracking process and engineering (third edition), 2015: 679, beijing: china petrochemical publishing society). If the slurry oil is not de-solidified, the slurry oil can only be treated or sold as low-value coking raw materials and low-grade fuel oil. The additional catalytic slurry oil solid removal and purification units, such as sedimentation, filtration, extraction, distillation, centrifugation, electrostatic separation and the like, have high investment and operation cost, have unsatisfactory effects and generate new dangerous waste, namely greasy dirt or oil with waste catalytic cracking catalyst powder. Chen Junwu it is concluded that for catalytic cracking slurry purification, "sedimentation separation method can remove solid impurities of slurry, but the efficiency is about 80% at maximum, and sedimentation time is long; the electrostatic separation method has higher separation efficiency, but the slurry properties and the operation conditions have great influence on the separation effect; the distillation method can completely remove impurities, but the yield of the clarified liquid is lower, and the excessive distillation temperature accelerates the slurry oil coking to influence the running period of the device, and meanwhile, a residue utilization way is still to be developed; the filtering separation method can remove more than 95% of solid impurities in the slurry oil, and the yield reaches more than 82%, but the investment is higher and the operation is complex. "(" catalytic cracking Process and engineering (third edition), 2015: 680-681, beijing: china petrochemical Press)

CN113755208A discloses a highly aromatic oil material, its preparation method and application. The process comprises (1) subjecting <99 wt% FCC feedstock to a catalytic cracking/cracking reaction to produce an oil gas; (2) Introducing the oil gas into the fractionation column below the scrubbing and desuperheating section, and countercurrent contacting with >1 wt.% of the remaining FCC feed oil to elute catalyst fines; (3) The eluted oil gas rises along the fractionating tower, enters a rectifying tower plate section and contacts with reflux liquid in a countercurrent way; (4) Withdrawing a high aromatic hydrocarbon oil from the side stream, and (5) carrying out a catalytic cracking/cracking reaction with the washed feedstock containing catalyst fines and the FCC feedstock in (1) to produce an oil gas; (6) repeating steps (2) - (5) to form a cycle. Wherein 97 wt.% of the oil and gas enters the high aromatic oil extraction plate. The residual catalytic cracking/cracking raw oil with the weight percent of more than or equal to 1 percent is preferably one or a combination of more of straight run atmospheric residuum, straight run vacuum residuum, hydrogenated atmospheric residuum, hydrogenated vacuum residuum, deasphalted oil and heavy crude oil. However, CN113755208A does not disclose the most suitable components of the feedstock, resulting in that part of the components with lower boiling points in the feedstock as the washing oil for the oil gas in the catalytic cracking reaction enter the high aromatic hydrocarbon oil fraction, which loses part of the components suitable for catalytic cracking, and reduces the aromaticity of the high aromatic hydrocarbon oil fraction, and is difficult to be used as the feedstock for products such as needle coke, carbon fiber, etc. which are produced from the feedstock with high aromaticity.

Thus, there is a need for a novel crude oil distillation and catalytic cracking combined crude oil processing unit.

Disclosure of Invention

The present utility model has been made to solve the above and other drawbacks of the prior art, and more particularly, to provide a device for processing crude oil by combining crude oil distillation and catalytic cracking, which converts low-value catalytic slurry oil into high-aromatic oil with high added value and high aromatic degree in high yield.

The utility model provides a device for processing crude oil by combining crude oil distillation and catalytic cracking, which comprises:

(1) An atmospheric distillation tower for atmospheric distillation of crude oil to provide an atmospheric distillation residue;

(2) A vacuum flash column downstream of the atmospheric distillation column for vacuum flashing the atmospheric distillation residue from the atmospheric distillation column to provide a vacuum flashed residue;

(3) A catalytic cracking reactor in communication with the atmospheric distillation column, the vacuum flash column, and the catalytic cracking fractionation column for receiving the atmospheric distillation residue, the distillate from the vacuum flash column, and the bottoms residue from the catalytic cracking fractionation column containing catalyst fines for catalytic cracking reactions to provide a reaction oil gas containing catalyst fines; and

(4) And the catalytic cracking fractionating tower is communicated with the vacuum flash tower and the catalytic cracking reactor and is used for washing catalyst powder in reaction oil gas from the catalytic cracking reactor at the bottom of the catalytic cracking fractionating tower and separating the reaction oil gas to provide high aromatic hydrocarbon oil material, diesel oil and mixed gas for subsequent production of gasoline, liquefied gas and dry gas.

In an embodiment of the utility model, the temperature, pressure and stripping steam amount of the vacuum flash tower are regulated so that the ratio of vacuum flash residue entering the high aromatic hydrocarbon oil under the operation condition of the bottom of the catalytic cracking fractionating tower is less than 10 mass%. Preferably, the proportion of the feed to the highly aromatic oil is < 1 mass%.

In an embodiment of the utility model, the distillate of the reduced pressure flash column is condensed into a liquid and then fed to a catalytic cracking reactor for catalytic cracking reaction.

In an embodiment of the utility model, the distillate of the reduced pressure flash column is fed in the gas phase to a catalytic cracking reactor by steam entrainment for catalytic cracking reactions.

Compared with the prior art, the utility model has the obvious advantages that:

(1) In the utility model, a vacuum flash tower is adopted to prepare the specific heavy fraction of the catalytic cracking raw material to replace catalytic cracking slurry oil or normal pressure/vacuum distillation residual oil to elute catalyst powder in catalytic cracking reaction oil gas, so that ash content in the high aromatic hydrocarbon oil is extremely low, and the high aromaticity of the high aromatic hydrocarbon oil is ensured, thereby meeting the requirements of raw materials of products such as needle coke, carbon fiber and the like. The selling price of the catalytic slurry with the catalyst powder is generally about 3000 yuan, and the selling price of the qualified needle coke raw material is 7000-9000 yuan. The annual tax of a catalytic cracking device of 100 ten thousand tons/year is more than 2 hundred million yuan based on the extraction of 5% of high aromatic hydrocarbon oil.

(2) In the utility model, for the current process flow of the refinery, only a decompression flash tower is needed to be added, so that the investment is low and the operation cost is low.

(3) Compared with a vacuum distillation tower, the vacuum flash tower has the advantages of less investment, low operation cost and reduced pressure, can be operated at lower residual pressure or higher vacuum degree than the vacuum distillation tower, and can obtain vacuum flash residue with higher boiling point at the same distillation temperature, thereby ensuring that the fraction of the reaction oil gas washing oil basically does not enter the high aromatic hydrocarbon oil fraction to reduce the aromatic degree of the high aromatic hydrocarbon oil. Stripping steam is blown into the bottom of the tower, which is beneficial to further reducing the content of lower boiling point compounds in residual oil, and ensures that the fraction of the reaction oil gas washing oil basically does not enter the high aromatic hydrocarbon oil fraction to reduce the aromaticity of the high aromatic hydrocarbon oil.

Drawings

FIG. 1 is a schematic diagram of an apparatus for processing crude oil by combining crude oil distillation and catalytic cracking according to the present utility model.

Wherein:

1-a crude oil atmospheric distillation tower; 2-a catalytic cracking reactor; 3-a reduced pressure flash column; 4-a catalytic cracking fractionating tower; 5-a catalytic raw material atomizing nozzle; 6-a gas-liquid separator; 7-crude oil feed line; 8-an atmospheric residuum extraction line; 9-a straight-run diesel oil extraction line; 10-naphtha withdrawal line; 11-an atmospheric tower top extraction line; 12-a catalytic cracking reaction oil gas outlet line; 13-a reduced pressure flash column stripping vapor line; 14-a reduced pressure flash overhead distillation line; 15-flash residuum withdrawal line; 16-washing raw oil into a reactor line; 17-a high aromatic oil extraction line; 18-heavy diesel extraction line; 19-light diesel oil extraction line.

Detailed Description

The apparatus and the application of the utility model will now be described in detail with reference to the accompanying drawings and examples, which are not intended to limit the utility model thereto.

As shown in fig. 1, the device for processing crude oil by crude oil distillation and catalytic cracking in combination comprises an atmospheric distillation tower 1, a catalytic cracking reactor 2 and a regenerator (not shown), a vacuum flash tower 3 and a catalytic cracking fractionating tower 4, wherein crude oil is separated by the atmospheric distillation tower 1 through a crude oil feeding line 7, straight-run diesel oil, naphtha and overhead distillate are pumped out through extraction lines 9, 10 and 11, atmospheric residue is pumped out through a tower bottom atmospheric residue pumping line 8 (8 a and 8 b), one part of the atmospheric residue enters the vacuum flash tower 3 through a pipeline 8a, the lower part of the vacuum flash tower 3 blows stripping steam through a vacuum flash tower stripping steam line 13, the bottom residue of the vacuum flash tower 3 enters the tower bottom of the catalytic cracking fractionating tower 4 through a flash residue pumping line 15 to wash catalyst powder in the reaction oil gas from the catalytic cracking reactor 2, then enters the catalytic cracking reactor line 16 together with the other part of the residual residue from a pipeline 8b (not shown in the figure) through a raw material atomizing nozzle 5 to perform catalytic cracking reaction, and the vacuum flash tower 3 enters the vacuum flash tower overhead line 14 separately or enters the other part of the residual gas from the catalytic cracking reactor through a side stream 12 to separate the residual gas from the catalytic distillation oil gas from the catalytic cracking tower 12 through a high pressure side stream 19, and the residual gas is separated from the residual gas is separated in the catalytic gas phase by the catalytic distillation gas side stream from the catalytic distillation tower 4 through a high pressure distillation side stream line 19, and the residual gas is separated from the residual gas is separated in the catalytic gas in the catalytic distillation gas phase of the catalytic distillation gas is separated from the catalytic distillation gas from the gas in the catalytic distillation tower 4. The heavy diesel oil can be extracted as a product or used for recycling. Heavy diesel oil may not be extracted.

In the present utility model, the connection and operation conditions between the respective constituent devices (e.g., an atmospheric distillation column, a catalytic cracking reactor and regenerator, a vacuum flash column and a catalytic cracking fractionation column, etc.) can be referred to conventional knowledge (e.g., as disclosed in CN 113755208) known to those of ordinary skill in the art.

In the present utility model, the vacuum flash column is a device for once vaporization under vacuum or equilibrium vaporization, and can be operated at a lower residual pressure than the vacuum distillation column, so that the boiling point of the residual oil can be higher by deep drawing of the distillate. Stripping steam is blown into the bottom of the tower, which is favorable for further reducing the content of lower boiling point compounds in the vacuum flash residue, and is a conventional technology in the petroleum refining industry.

Since the boiling point of the washing oil of the reaction oil gas at the bottom of the catalytic cracking fractionating tower should be basically larger than that of the reaction oil gas, the catalyst powder in the reaction oil gas can be washed, and the ideal component of the high aromatic hydrocarbon oil extracted from the upper part of the washing section is basically free of washing oil components, because the aromatic degree of the washing raw oil is lower, the washing raw oil is not suitable for being used as the raw materials of high aromatic needle coke, carbon fiber and the like. The temperature, pressure and stripping steam amount of the vacuum flash tower are such that the ratio of vacuum flash residue entering the high aromatic hydrocarbon oil fraction under the operation condition of the bottom of the catalytic fractionating tower is less than 10% (mass), preferably less than 1% (mass).

In one embodiment of the utility model, the distillate of the reduced pressure flash column may be condensed to liquid before entering the catalytic cracking reactor alone or with other feedstock.

In another preferred embodiment of the utility model, the distillate of the reduced pressure flash column may be entrained by steam to enter the catalytic cracking reactor in the vapor phase alone or with other feedstock.

Examples

The advantages of the present utility model will become more apparent by the following detailed description of the present utility model in conjunction with the specific embodiments. It is to be understood that the description is intended to be illustrative only and is not to be taken in any way as limiting the scope of the utility model. The experimental procedures, which are not specified in the following examples, are generally carried out under conventional conditions or under conditions recommended by the manufacturer.

In an embodiment, the crude oil:

daqing crude oil is obtained from oil refineries of Daqing petrochemical company;

catalytic cracking catalyst used in examples:

semi-synthetic catalyst: LC-6 (available from lanzhou catalyst plant);

in-situ crystallization catalyst: FCA-100D was obtained from Shanghai Nake auxiliary Co.

Example 1

As shown in fig. 1, daqing crude oil is separated into naphtha, straight-run diesel oil and atmospheric residuum by an atmospheric distillation tower 1, 80% by mass of the atmospheric residuum enters a catalytic cracking reactor 2 for catalytic cracking reaction, and the reacted oil gas is introduced below a herringbone baffle plate of a catalytic cracking fractionating tower 4; the 20% (mass) of atmospheric residuum is heated and then enters a vacuum flash tower 3 for flash evaporation, distillate is condensed and then is mixed with other feeds of catalytic cracking, the mixture enters a catalytic cracking reactor 2, the vacuum flash residuum enters the upper part and the lower part of a herringbone baffle plate of a catalytic cracking fractionating tower 4, is pumped out from the bottom of the fractionating tower 4, circulates to the upper part of the herringbone baffle plate, washes catalyst powder in reaction oil gas, and the washed reaction oil gas rises from bottom to top along the fractionating tower 4, sequentially pumps out high aromatic hydrocarbon oil, light diesel oil from a lateral line, and separates gasoline, liquefied gas and dry gas in a subsequent separation system. After the washing cycle oil at the lower part of the fractionating tower 4 reaches a preset amount, the washing raw material oil with the catalyst powder is extracted, mixed with other catalytic cracking raw materials, and then enters the catalytic cracking reactor 2 for catalytic cracking reaction, and the operation is carried out in a stable state. The steady operating conditions and product distribution of each of the above units and the properties of the highly aromatic oil are shown in table 1.

Examples 2 to 3

Crude oil was processed in combination with catalytic cracking to produce high aromatic oil and other products in a similar manner to the procedure described in example 1, following the conditions described in table 1. The product distribution and properties of the highly aromatic oil of examples 2-3 can be seen in Table 1.

Comparative example 1

The catalytic cracking reaction and subsequent fractionation operations were performed in a manner similar to example 1, following the conditions described in table 1 below. The difference is that the vacuum residue of the atmospheric and vacuum distillation unit of the refinery is used as the washing raw oil of the catalytic cracking reaction oil gas. The product distribution and the properties of the high aromatic hydrocarbon oil are shown in Table 1.

Comparative example 2

The catalytic cracking reaction and subsequent fractionation operations were performed in a manner similar to example 1, following the conditions described in table 1 below. The difference is that the atmospheric residuum is directly used as the washing raw oil of the catalytic cracking reaction oil gas. The product distribution and the properties of the high aromatic hydrocarbon oil are shown in Table 1.

TABLE 1

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Application example 1

Comparing tables 1 and 2, it can be seen that the high aromatic hydrocarbon oil produced by the present utility model satisfies the requirements of the raw materials for preparing needle coke.

TABLE 2 requirements for feedstock properties for needle coke

Properties of (C)	Index (I)
		Density (20 ℃): g/cm 3	≥1.03
Sulfur content: % of (B)	≤0.5
		Asphaltenes: % of (B)	<1.0
Aromatic component (aromatic hydrocarbon content): % of (B)	≥45
		Ash content: mu g/g	<100

The foregoing description is only illustrative of the present utility model and is not intended to limit the scope of the utility model, and all equivalent structures or equivalent processes or direct or indirect application in other related technical fields are included in the scope of the present utility model.

Claims (1)

1. A device for processing crude oil by combining crude oil distillation and catalytic cracking, which is characterized by comprising an atmospheric distillation tower, wherein the atmospheric distillation tower is used for performing atmospheric distillation on the crude oil to provide atmospheric distillation residual oil; a vacuum flash column downstream of the atmospheric distillation column for vacuum flashing the atmospheric distillation residue from the atmospheric distillation column to provide a vacuum flashed residue; a catalytic cracking reactor in communication with the atmospheric distillation column, the vacuum flash column, and the catalytic cracking fractionation column for receiving the atmospheric distillation residue, the distillate from the vacuum flash column, and the bottoms residue from the catalytic cracking fractionation column containing catalyst fines for catalytic cracking reactions to provide a reaction oil gas containing catalyst fines; and a catalytic cracking fractionating tower communicated with the vacuum flash tower and the catalytic cracking reactor, for washing catalyst powder in reaction oil gas from the catalytic cracking reactor at the bottom of the catalytic cracking fractionating tower and separating the reaction oil gas to provide high aromatic hydrocarbon oil, diesel oil and mixed gas for subsequent production of gasoline, liquefied gas and dry gas.

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