CN113755208B

CN113755208B - High aromatic hydrocarbon oil material and preparation method and application thereof

Info

Publication number: CN113755208B
Application number: CN202111121764.2A
Authority: CN
Inventors: 陆明全; 陆善祥; 李明晖
Original assignee: Shanghai Xianjia Chemical Co ltd; Shanghai Nake Auxiliaries Co ltd
Current assignee: Shanghai Xianjia Chemical Co ltd; Shanghai Nake Auxiliaries Co ltd
Priority date: 2021-09-24
Filing date: 2021-09-24
Publication date: 2023-04-25
Anticipated expiration: 2041-09-24
Also published as: CN113755208A

Abstract

The invention relates to a high aromatic hydrocarbon oil material, a preparation method and application thereof. The method comprises the following steps: (1) Catalytically cracking/cracking less than or equal to 99 wt% of FCC feed oil to produce oil gas; (2) Introducing the oil gas into the lower part of a washing and de-superheating section of the fractionating tower, and carrying out countercurrent contact with the residual FCC raw oil with the weight percent of more than or equal to 1 percent so as to elute catalyst powder; (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 from the side stream a high aromatic oil comprising ash <20 μg/g; and (5) carrying out catalytic cracking/cracking reaction of the washed feed oil containing the catalyst powder and the FCC feed oil in (1) together to produce oil gas; (6) repeating steps (2) - (5) to form a cycle. Wherein greater than or equal to 97 wt% of the oil gas enters the high aromatic oil extraction plate. The method has simple process, less equipment investment and greatly reduced operation cost.

Description

High aromatic hydrocarbon oil material and preparation method and application thereof

Technical Field

The invention relates to the field of petroleum refining, in particular to a high aromatic hydrocarbon oil prepared by catalytic cracking/pyrolysis, and a preparation method and application thereof.

Technical Field

Catalytic cracking/cracking is one of the most important lightening processes in the oil refining industry and the main profit source. The main products are divided into products such as gasoline, diesel oil, liquefied gas, dry gas, slurry oil and the like through a fractionating tower and an absorption stabilizing system. Early wax oil catalytic cracking has low slurry yield due to light raw materials, and slurry is basically used for recycling, so that slurry products are not produced. The existing catalytic cracking/cracking device basically adopts heavy raw materials, wherein the slurry oil yield is high, the total recycling or most recycling can lead to high coke yield of the system, the catalyst activity is reduced, the product distribution is poor, and the regeneration system is difficult to bear and can only throw outwards. The slurry oil which is thrown outwards contains a large amount of solid matters (2-6 g/L) such as catalyst powder and the like. If the catalyst powder and other solids 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, petroleum sulfonate surfactants and the like, and fuel oil blending components. The solid content requirements are shown in Table 1 (main edition such as Chen Junwu, catalytic cracking Process and engineering (third edition), 2015: 679, beijing: china petrochemical Press). Can only be treated or sold as low-value coking raw materials and low-grade fuel oil without being de-solidified. 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 have new dangerous waste, namely greasy dirt or oil with waste catalytic cracking/cracking catalyst powder. Chen Junwu et al conclude that: for catalytic cracking slurry oil purification, the sedimentation separation method can remove solid impurities of the slurry oil, but the efficiency is about 80 percent at the highest, and the sedimentation time is longer; 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)

TABLE 1 requirements of different petrochemical products on slurry solids content

Product(s)	Solids content/. Mu.g/g
		Carbon black or rubber filler	<500
Needle coke	<100
		Carbon fiber	<20
Hydrotreated (cracked) feedstock	<20
		Blending component of fuel oil	<200

CN100549141C discloses a raw material pretreatment method for producing needle coke: the non-ideal components of raw oil are removed by reduced pressure distillation, the ideal components are contacted with hydrogen and hydrogenation catalyst, and hydrogenation flow is separated to obtain the raw material for producing needle coke. When the feedstock is a catalytic cracking slurry or clarified oil, it must be filtered to remove catalyst fines and thereby reduce ash. In the examples, the catalytically clarified oil was distilled under reduced pressure at 400℃and 20.5% by weight was distilled off.

Dingwen reports the use of a slurry oil reduced pressure topping device for the production of needle coke feedstock. The pressure reducing tower top is 2.5-3.5kPa, and 61.5 wt% is distilled off at 390-420 ℃. Only the middle fraction of the vacuum tower is used as a precursor raw material for producing needle coke. Not only is a pressure reducing tower added, but also the bottom slurry is still difficult to treat. ("China petrochemical 2016 years catalytic cracking technology communication theory & ltth & gt 50-54 & gt)

Lin Min reports "application of slurry depressurization topping process to catalytic cracker", the 320℃slurry was fed directly into a depressurization column evacuated by a two-stage steam jet pump, only 30% by weight was distilled off. ("chemical industry management" 2014 (11): 229-230)

CN112725031a discloses an "oil suitable for producing needle coke, a preparation method and a system thereof", in which catalytic cracking slurry oil or catalytic cracking clarified oil or other raw materials are fractionated by a distillation tower to obtain crude wax oil and bottom oil, and then the four steam stripping, hydrogenation, polycondensation and other processes are performed to obtain the needle coke raw materials, so that the equipment investment and operation cost are very high.

Lijun reports an early wax oil catalytic cracking "effective technical improvement", wherein the raw materials are directly fed into a fractionating tower bottom and directly fed into a riser reactor after mixed heat exchange with slurry oil. ("Beijing energy conservation", 1990 (3), 14-15).

CN106924984B discloses a method of controlling the column bottom level and reaction severity of a fractionation column. Introducing a catalytic cracking raw oil medium into the side wall of the fractionating tower near the vertical height of the herringbone plate at the bottom of the fractionating tower, solving the problem that the liquid level at the bottom of the fractionating tower fluctuates after the severity of catalytic cracking reaction changes, and controlling the coking at the bottom of the fractionating tower. However, there is still a large amount of catalytic slurry with a large amount of catalyst powder produced. In fact, as already described in the technical questions and answers of catalytic cracking units (main code Ma Bawen, pages 161-162) published in 1993, "when the liquid level (at the bottom of the fractionation column) drops too low to be regulated," … … may temporarily replenish the feedstock oil (or reactor feed) directly to the bottom of the column to maintain the liquid level ". Because the increase of the reaction severity leads to the decrease of the liquid level at the bottom of the fractionating tower, the control of the liquid level at the bottom of the fractionating tower and the reaction severity is a matter. Thus, the technology disclosed in CN106924984B has been known in practice for a long time.

CN112574777a discloses a process technology and method for stopping the production of slurry oil by catalytic cracking and cracking device. The method comprises the steps of changing the reaction conditions of catalytic cracking and cracking, improving the depth of the cracking reaction, realizing the one-way deep conversion of the reaction, enabling no slurry components to exist in the reaction product after adjustment, leading the raw oil, residual oil in the raw oil or heavy oil components to be strung into the fractionating tower bottom through a fractionating accident bypass line or a slurry lower return tower line to replace the slurry components, keeping the normal circulation of the slurry, and returning the materials strung into the tower bottom and the washed catalyst dust to a reaction regeneration system to be mixed with the raw oil for recycling. However, CN112574777a does not mention how to increase the reaction depth, nor does it mention specific implementation details and implementation methods. Even if the scheme is feasible, the method is only suitable for deep single-pass cracking without generating macromolecular components of slurry oil, and no method for improving the reaction depth capable of achieving the purpose is disclosed and reported at present.

With current heavy feedstock catalytic cracking/cracking units and processes, there is no exception to the slurry components that produce large amounts of catalyst fines. Thus, there is a need for a novel, simple and efficient process for converting catalytic slurry oils to high aromatic oils of high added value in high yields.

Disclosure of Invention

The invention aims to solve the above and other defects in the prior art, and in particular provides a high aromatic hydrocarbon oil material, a preparation method and application thereof with low investment and low operation cost.

In order to achieve the above object, the present invention provides, in one aspect, a method for producing a high aromatic hydrocarbon oil, the method comprising:

(1) Feeding less than or equal to 99 wt% of the catalytic cracking/pyrolysis raw oil into a catalytic cracking/pyrolysis reactor containing a catalyst to perform catalytic cracking/pyrolysis reaction to generate oil gas, wherein the weight of the catalytic cracking/pyrolysis raw oil is 100 wt%;

(2) Introducing the oil gas into the lower part of a washing and superheating section of a catalytic cracking/pyrolysis fractionating tower, and countercurrent contacting the oil gas with more than or equal to 1 weight percent of residual catalytic cracking/pyrolysis raw oil in the washing and superheating section to elute catalyst powder in the oil gas;

(3) The oil gas after the catalyst powder is eluted from the washing and de-superheating section rises along the catalytic cracking/cracking fractionating tower, enters a rectifying tower plate section of the fractionating tower and is in countercurrent contact with the reflux liquid from the upper part of the rectifying tower;

(4) Extracting liquid oil from a side line of a rectifying tower plate section adjacent to the washing and de-superheating section to obtain the high-aromatic oil, wherein the high-aromatic oil contains ash content of less than 20 mug/g; and

(5) The washing raw oil containing the catalyst powder and extracted from the bottom of the fractionating tower are sent to a catalytic cracking/cracking reactor together with the catalytic cracking/cracking raw oil in the step (1) to carry out catalytic cracking/cracking reaction to generate oil gas;

(6) Repeating steps (2) - (5) to form a cycle.

Wherein not less than 97% by weight of the oil gas enters the high aromatic oil extraction plate, preferably not less than 99% by weight of the oil gas enters the high aromatic oil extraction plate.

In one embodiment of the invention, after the catalytic cracking/cracking reaction in step (1) and step (5), the catalyst is returned to the catalytic cracking/cracking reactor after being regenerated in a regenerator.

In one embodiment of the invention, the high aromatic oil extraction plate temperature is 1-150 ℃ higher than the cycle oil extraction plate temperature, preferably the high aromatic oil extraction plate temperature is 5-120 ℃ higher than the cycle oil extraction plate temperature.

In one embodiment of the invention, the oil gas entering the high aromatic oil extraction plate contains additional low molecular gas; the low molecular gas is selected from one or more of steam, hydrocarbon compounds or mixtures with boiling points lower than that of high aromatic hydrocarbon oil materials or oxygen-containing organic matters.

In one embodiment of the invention, the high aromatic oil extraction plate temperature is 1-120 ℃ higher than the cycle oil extraction plate temperature, preferably the high aromatic oil extraction plate temperature is 1-100 ℃ higher than the cycle oil extraction plate temperature; meanwhile, the oil gas entering the high aromatic hydrocarbon oil extraction plate contains additional low molecular gas; the low molecular gas is selected from one or more of steam, hydrocarbon compounds or mixtures with boiling points lower than that of high aromatic hydrocarbon oil materials or oxygen-containing organic matters.

The low molecular gas is added from any position below the high aromatic hydrocarbon oil extraction plate of the catalytic cracking/cracking reaction unit and the fractionating tower, preferably from the inlet of the lifting gas of the lifting pipe reactor and/or the inlet of the stripping steam of the catalyst stripping section and/or the inlet of the stirring steam at the bottom of the fractionating tower and/or the inlet of the settler Jiao Zhengqi and/or the inlet of the raw oil of the lifting pipe reactor.

In the present invention, the amount of the additionally added low molecular gas may be 0 to 100 wt%, preferably 0 to 80 wt%, of the amount of the reaction oil gas originally introduced into the fractionating tower to ensure that not less than 97 wt% of the reaction oil gas enters the high aromatic oil extraction plate, preferably not less than 99 wt% of the oil gas enters the high aromatic oil extraction plate.

In one embodiment of the present invention, the ≡1 wt% of the residual catalytic cracking/cracking feedstock is preferably selected from one or more of straight run atmospheric residue, straight run vacuum residue, hydrogenated atmospheric residue, hydrogenated vacuum residue, deasphalted oil, heavy crude oil.

In one embodiment of the invention, the ≡1% by weight of the remaining catalytic cracking/pyrolysis feedstock is introduced into the catalytic cracking/pyrolysis fractionation column above, below or both the wash-off superheating section.

In one embodiment of the present invention, a part of the washing raw oil containing the eluted catalyst powder in the step (2) is recycled to the upper part or the upper part and the lower part of the washing and desorbing section after being cooled by heat exchange, wherein the washing raw oil recycled to the upper part of the washing and desorbing section is in countercurrent contact with the oil gas so as to elute the catalyst powder in the oil gas; the washing raw oil circulated back to the lower part of the washing and de-superheating section cools the washing raw oil positioned at the bottom of the tower; the other part of the washing raw oil and the catalytic cracking/cracking raw oil in the step (1) are sent together to a catalytic cracking/cracking reactor containing a catalyst to carry out catalytic cracking/cracking reaction;

in one embodiment of the invention, the washing and de-superheating section in the catalytic cracking/pyrolysis separation column comprises 6-20 layers of herringbone baffles or regular grid packing; the rectification column plate section comprises 26-50 layers of column plates, and 1-4 circulation reflux flows are arranged in the rectification column plate section.

In one embodiment of the invention, in the catalytic cracking/pyrolysis fractionating tower, high aromatic hydrocarbon oil and diesel oil are sequentially extracted from bottom to top, and then separated by a subsequent gas-liquid separator and an absorption stabilization system to obtain gasoline, liquefied gas and dry gas.

In one embodiment of the invention, the diesel oil is separated into light diesel oil and heavy diesel oil, and the heavy diesel oil and the light diesel oil are sequentially extracted from bottom to top in the catalytic cracking/cracking fractionating tower, wherein the heavy diesel oil is recycled to the catalytic cracking/cracking reactor containing the catalyst to perform catalytic cracking/cracking reaction or output as a product.

In one embodiment of the present invention, the catalytic cracking/pyrolysis raw oil is selected from one or more of straight-run wax oil, straight-run atmospheric residue, straight-run vacuum residue, hydrogenated wax oil, hydrogenated atmospheric residue, hydrogenated vacuum residue, coker wax oil, coker hydrogenated wax oil, deasphalted oil, shale oil, tar sand oil, heavy crude oil, inferior diesel oil, animal oil, vegetable oil, and synthetic oil.

In one embodiment of the invention, the catalytic cracking/cracking reactor is of all types of catalytic cracking/cracking reactors currently available, including coaxial or high-low parallel riser reactors, MIP, MIP-CGP, MIP-LTG, MIP-DCR, FDFCC, DCC, CPP, HCC, MGG, MGD, TSRFCC, HSCC, IHCC and the like.

In one embodiment of the invention, the catalyst is selected from one or more of a cohesive Y, ZSM-5, a beta molecular sieve and a composite catalyst thereof, an in-situ crystallization Y-type catalyst, a propylene aid, an octane aid, a sulfur reduction catalyst, a nitrogen reduction catalyst and a heavy metal resistant catalyst.

In one embodiment of the invention, the reaction temperature of the catalytic cracking/cracking reaction is 480-650 ℃, the pressure is 0.1-0.5 Mpa, the regeneration temperature of the catalyst is 650-780 ℃, and the mass ratio of the catalyst to the catalytic cracking/cracking raw oil is 2-10.

In one embodiment of the invention, the high aromatic hydrocarbon oil comprises at least 45 wt% total aromatic hydrocarbons, asphaltenes<1 wt%, sulfur content<0.5 wt% and density (20 ℃) of more than or equal to 1.03g/cm ³ And ash content<20μg/g。

In another aspect, the invention provides a high aromatic oil comprising an ash of <20 μg/g.

In one embodiment, the present invention provides a high aromatic hydrocarbon oil comprising at least 45 wt.% total aromatic hydrocarbons, asphaltenes<1 wt%, sulfur content<0.5 wt% and density (20 ℃) of more than or equal to 1.03g/cm ³ And ash content<20μg/g。

In yet another aspect, the invention provides the use of the high aromatic oil in the preparation of needle coke, carbon fiber, carbon black, rubber softeners and fillers, petroleum aromatic plasticizers, heat transfer oils, petroleum sulfonate surfactants, blend fuel oils, hydrotreated (cracked) feedstock.

Compared with the prior art, the invention has the obvious advantages that:

1. in the invention, the catalytic cracking/cracking reaction oil gas is in countercurrent contact with the circulating washing raw oil and/or part of the catalytic cracking/cracking raw oil extracted from the bottom of the fractionating tower in the tower bottom washing and de-superheating section, catalyst powder in the reaction oil gas is eluted, the extracted high aromatic hydrocarbon oil with extremely low ash content can be directly used for producing carbon materials with high added value, fine chemical products and blended fuel oil, the step of removing catalyst powder, such as filtration, reduced pressure distillation or solvent extraction, necessary for producing the carbon materials with high added value, the fine chemical products and the blended fuel oil, by using the catalytic slurry oil is omitted, and the equipment investment and the operation cost are greatly saved.

2. The invention omits recycle oil with low hydrogen/carbon ratio and recycle oil slurry in the prior art, greatly reduces coke generation, improves the processing capacity of the catalytic cracking/cracking device, remarkably improves the product distribution, not only improves the yield of high-benefit products such as gasoline, diesel oil and liquefied gas of the catalytic cracking/cracking device, but also provides a large amount of short-cut high aromatic hydrocarbon oil with high added value.

3. According to the data calculation of the embodiment of the invention, the invention is implemented by a set of existing 100 ten thousand tons/year catalytic cracking/cracking device, and the economic benefit of at least more than 2 hundred million yuan per year can be increased.

Drawings

The invention may be better understood by describing exemplary embodiments thereof in conjunction with the accompanying drawings. In the drawings of which there are shown,

FIG. 1 is a process schematic of a process for producing a high aromatic hydrocarbon oil in one embodiment of the invention.

The numbering is as follows:

1. catalytic cracking/pyrolysis settler; 2. catalytic cracking/pyrolysis fractionation column; 3. a gas-liquid separator; 4a, raw wax oil; 4b, raw material heavy oil; 5. a mixed feed line; 6. a reaction atomizing nozzle; 7. a riser reactor; 8. lifting the gas; 9. a catalyst stripping section; 10. stripping the vapor; 11. a reaction oil gas outlet line; 12 (12 a and 12 b) feeding the heavy feedstock to a fractionation column line; 13. washing and removing the overheated section; 14. a column bottom washing raw oil extraction line; 15. a fractionation column bottom heat exchanger; 16 (16 a and 16 b) washing the raw oil circulation line; 17. washing raw oil into a reactor line; 18. rectifying tower plate sections of the fractionating tower; 19. a high aromatic oil extraction line; 20. a heavy diesel extraction line; 21. a heavy diesel oil recycling line; and 22. A light diesel extraction line.

Detailed Description

The present invention will be described more fully hereinafter with reference to exemplary embodiments thereof. These exemplary embodiments are described so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Indeed, this invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; and, these embodiments are provided so that this disclosure will satisfy applicable legal requirements.

In addition, under the condition of no conflict, the technical features given in the specific embodiments of the present application can be combined with each other to form a complete technical scheme and are within the scope of the disclosure of the present invention.

In the present invention, the manner of connection between the systems/devices should be understood in a broad sense unless explicitly stated or limited otherwise. For example, the pipe connection can be direct pipe connection, pipe connection through conventional conveying, metering and controlling equipment such as pumping equipment, metering equipment, valve pipe fittings and the like, and can be fixed connection or detachable connection. The specific meaning of the above terms in the present invention can be understood by those skilled in the art according to the specific circumstances.

In the present invention, the term "catalytic cracking/cracking feedstock (FCC feedstock)" refers to conventional catalytic cracking/cracking feedstock of refineries, including feedstock wax oils, such as: straight-run wax oil, hydrogenated wax oil, coked hydrogenated wax oil and hydrocracking tail oil; feedstock heavy oils, for example: straight run atmospheric residue (normal residue), straight run vacuum residue (reduced residue), hydrogenated atmospheric residue (hydrogenated normal residue), hydrogenated vacuum residue (hydrogenated reduced residue), deasphalted oil (DAO), heavy crude oil; also included are unconventional raw oils such as: shale oil, tar sand oil, inferior diesel oil, animal oil, vegetable oil, synthetic oil, waste lubricating oil, low-value oil in oil refining and petrochemical processes, and the like.

In the present invention, the term "high aromatic hydrocarbon oil" refers to liquid oil which is withdrawn from a side draw-off plate of a catalytic cracking/pyrolysis fractionation column immediately adjacent to the scrubbing and desorbing section when greater than or equal to 97 wt% of the catalytic cracking/pyrolysis reaction oil enters the draw-off plate, and has an ash content of <20 μg/g.

In the present invention, the term "catalyst to oil ratio" refers to the mass ratio of the catalyst used in the catalytic cracking reaction to the catalytic cracking/pyrolysis feedstock.

In the present invention, the term "wash feed oil" means an oil which is withdrawn from the bottom of a fractionation column after countercurrent contact of an oil gas from a catalytic cracking/cracking reactor with 1% by weight or more of a catalytic cracking/cracking feed oil and/or a catalyst powder-containing oil which is withdrawn at the bottom of the fractionation column on the premise that 1% by weight or more of a catalytic cracking/cracking feed oil is strung above and/or below a wash superheating section of the fractionation column.

In the present invention, the term "cycle oil" refers to heavy cycle oil that is returned to the catalytic cracking/cracking reaction unit for recovery by side draw of the fractionating tower on the premise of existing external slurry slinger at the fractionating tower bottom of a conventional catalytic cracking/cracking unit. The term "cycle oil draw plate temperature" refers to the temperature of the cycle oil draw plate at the current catalytic cracking/pyrolysis fractionation column, typically 310-330 ℃, and in the present example 320 ℃ is taken as the "baseline". If the temperature of the recycle oil extraction plate of the fractionating tower of the current device is 10 ℃ higher, the reference temperature is correspondingly increased by 10 ℃, and the rest is the same.

In the present invention, the cycle oil withdrawal of the existing catalytic cracking/pyrolysis fractionation column may be used as the withdrawal of the high aromatic oil of the present invention. In a preferred embodiment, the high aromatic oil may have 2 to 5 withdrawal ports on different levels of trays and the withdrawal position may be adjusted according to the nature of the withdrawn oil component. In the present invention, the temperature of the draw plate of the high aromatic oil is usually 1 to 150 ℃, preferably 5 to 120 ℃, higher than the temperature of the recycle oil draw plate of the existing catalytic cracking/pyrolysis fractionation column (hereinafter also referred to as reference), the upper limit of the temperature being selected to ensure that no coking occurs in the system and that long-term operation is possible; the lower limit is selected to ensure that greater than or equal to 97 wt% of the oil and gas enters the high aromatic oil extraction plate, preferably greater than or equal to 99 wt% of the oil and gas enters the high aromatic oil extraction plate.

The present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the drawings described herein are not intended to limit the scope of the present invention.

As shown in fig. 1, a mixed feedstock (FCC feedstock) comprising feedstock wax oil and feedstock heavy oil is introduced into a riser reactor 7 from a reaction atomizing nozzle 6 through

lines

4a, 4b and 5, contacted with a regenerated catalytic cracking/cracking catalyst (not shown) lifted by a lift gas 8 and subjected to a catalytic cracking/cracking reaction to form reaction oil gas. If a MIP reactor is used, the riser has a corresponding enlarged portion (not shown). The reaction oil gas is separated from the catalyst in the settler 1, is pumped out from the top of the settler 1 via a reaction oil gas outlet line 11 and is introduced below a wash-off superheating section 13 of a subsequent fractionation column 2. Under the action of gravity, the catalytic cracking/cracking catalyst is stripped by stripping steam 10 in a stripping section 9 to extract the absorbed oil gas, and the absorbed oil gas is taken as a spent catalyst (not shown) to enter a regenerator for regeneration.

The heavy oil raw material from the heavy raw material feeding

fractionating tower lines

12, 12a, 12b respectively enter the upper and lower parts of the washing and de-superheating section 13. The washing raw oil extracted from the bottom of the fractionation tower is recycled to the upper and lower parts of the washing and desuperheating section 13 after heat exchange through a pipeline 14 and a heat exchanger 15. The heavy oil raw material and the circulating washing raw material oil entering the upper part of the washing and de-superheating section 13 are fully and countercurrent contacted with the reaction oil gas in the washing and de-superheating section so as to elute the catalyst powder contained in the reaction oil gas. The temperature of the bottom of the fractionating tower is regulated by the raw material heavy oil and the circulating washing raw material oil which enter the lower part of the washing and de-superheating section 13. The total amount and proportion of heavy feedstock oil introduced from the heavy feedstock into the

fractionating tower lines

12a, 12b, respectively, and the total amount and proportion of recycle wash feedstock oil introduced via the

lines

16a, 16b may be determined according to the desired eluted catalyst fines content in the reaction oil gas from the catalytic cracking reactor. If the amount of catalyst fines to be eluted is large, the ratio of feedstock heavy oil introduced from the heavy feedstock into fractionation column line 12b to recycle wash feedstock introduced from wash feedstock recycle line 16b is high. This can be adjusted in real time as needed in actual operation.

After the elution desuperheating, the reaction oil gas rises into the fractionation column rectifying tray section 18. While the wash feed oil comprising catalyst fines is withdrawn from the bottom via a bottom wash feed oil withdrawal line 14. Part of the washing raw oil is fed into the riser reactor 7 together with the mixed raw oil from the mixed raw oil feed line 5 via the washing raw oil feed line 17 as circulating washing raw oil, and the other part is subjected to catalytic cracking/cracking reaction.

In fig. 1, the reaction oil gas after the elution treatment rises into a fractionation column rectifying tray section 18, and after fractionation by, for example, 1 to 8 rectifying trays, the high aromatic hydrocarbon oil is withdrawn from a high aromatic hydrocarbon oil withdrawal line 19 of the fractionation column 2. After fractionation by, for example, 4 to 25 rectification trays, heavy diesel is withdrawn from the heavy diesel withdrawal line 20 of the fractionation column 2. After fractionation by, for example, 4-20 trays, light diesel is withdrawn from the light diesel withdrawal line 22 of the fractionation column 2. At the top of the fractionating tower 2, after the reaction oil gas is subjected to heat exchange, a gas-liquid separator 3, and cooled, gasoline, liquefied gas, and dry gas (not shown) are formed. In a specific embodiment, the heavy diesel oil withdrawn from the heavy diesel oil withdrawal line 20 may be fed into the riser reactor 7 via the heavy diesel oil recycling line 21 together with the wash feed oil from the wash feed oil feed line 17 and the mixed feed oil from the mixed feed oil feed line 5 to perform the catalytic cracking/cracking reaction again. The heavy diesel oil can be extracted as a product without recycling.

In a specific embodiment of the present invention, the catalytic cracking/pyrolysis feedstock entering the bottom of the fractionation column is preferably deasphalted oil (DAO), normal slag, hydrogenated normal slag, reduced slag or hydrogenated reduced slag, more preferably reduced slag or hydrogenated reduced slag or DAO.

In a specific embodiment of the present invention, it is preferred that the high aromatic oil extraction plate temperature is 5-120 ℃ higher than the temperature of the current conventional catalytic cracking/pyrolysis fractionation column cycle oil extraction plate (also referred to hereinafter as baseline) such that greater than or equal to 97 wt.% of the reaction oil gas enters the high aromatic oil extraction plate, preferably greater than or equal to99 wt.% of the oil and gas enters the high aromatic oil extraction plate. The high aromatic oil comprises ash<20. Mu.g/g. Preferably, the high aromatic oil comprises at least 45 wt% total aromatics, asphaltenes<1 wt%, sulfur content<0.5 wt% and density (20 ℃) of more than or equal to 1.03g/cm ³ And ash content<20μg/g。

In the present invention, one of ordinary skill in the art will appreciate how to control the high aromatic oil extraction plate temperature based on conventional means and knowledge. For example, the high aromatic oil extraction plate temperature may be controlled by adjusting the quality and temperature of the feed oil introduced to the fractionation column, adjusting the heat removal from the heat exchanger 15, adjusting the heat removal from the mid-section reflux (not shown), and the like.

In a specific embodiment of the invention, the low molecular gas is selected from water vapor, hydrocarbon compounds or mixtures having a boiling point lower than that of high aromatic hydrocarbon oils, or oxygen-containing organics. In the present invention, the oil gas entering the high aromatic extraction plate is made to contain additional low molecular gas. In particular embodiments, the low molecular gas may be introduced into the catalytic cracking/cracking reaction unit and fractionation column high aromatic oil extraction plate anywhere below, preferably from the riser reactor 7 inlet and/or the inlet of stripping vapor 10 of catalyst stripping section 9 and/or the inlet of stirred vapor at the bottom of the fractionation column (not shown) and/or the anti-coking vapor inlet of settler 1 (not shown) and/or the riser reactor FCC feed oil inlet, with additional low molecular gas added to the subsequent fractionation column high aromatic oil extraction plate along with the reaction oil gas produced in the reaction unit.

In the invention, the high aromatic hydrocarbon oil prepared by the method is applied to the preparation of needle coke, carbon fiber, carbon black, rubber softener and filler, petroleum aromatic hydrocarbon plasticizer, heat conduction oil, petroleum sulfonate surfactant, blended fuel oil and raw materials for hydrotreatment (cracking).

Examples

The advantages of the present invention will become more apparent by the following detailed description of the present invention 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 invention. 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 embodiments, the FCC feedstock oil:

paraffin base, such as wax oil (VGO), vacuum residue (reduced residue), and atmospheric residue (normal residue), obtained from Ulmus oil refinery of prolonged petrochemical company;

intermediate base: VGO, slag reduction and normal slag are obtained from the Qilu petrochemical company victory oil refinery;

middle east import: VGO, slag reduction, normal slag, hydrogenated normal pressure residual oil (hydrogenated normal slag), hydrogenated vacuum residual oil (hydrogenated reduced slag) and coked wax oil are obtained from the oil refining part of Shanghai petrochemical company.

Deasphalted oil (DAO): obtained from Jinan petrochemical company.

Catalytic cracking/cracking catalyst used in the examples:

semi-synthetic catalyst: CDC, CDOS, CGP-C (from the Kaolin catalyst plant), HDO-70 (from the Lanzhou catalyst plant), COKC (from the Zhou catalyst plant);

in-situ crystallization catalyst: FCA-100A, FCA-100D, FCA-100M, FCA-100S (sulfur reduction catalyst) were all obtained from Shanghai Nake auxiliary agent Co., ltd.

Catalytic cracking catalyst: DMMC-1, from Anqing petrochemical company; FCP-1 catalytic cracking catalyst, obtained from Shanghai Nake auxiliary Co., ltd.

Example 1

As shown in fig. 1, the FCC feedstock and the catalytic cracking/cracking catalyst undergo catalytic cracking/cracking reactions in a riser reactor 7 to form reaction oil gas. The operating conditions of the catalytic cracking/cleavage reaction are shown in table 2 below.

As shown in fig. 1, this reaction oil gas from the reaction unit is fed to the catalytic cracking/pyrolysis fractionation column 2 below the scrub and superheat section, and the reaction oil gas is sufficiently contacted with FCC feedstock oil in the scrub and superheat section 13 to elute catalyst fines contained in the reaction oil gas. The operating conditions of the fractionation column are shown in table 2 below.

In the fractionating tower, high aromatic hydrocarbon oil, heavy diesel oil (according to the requirement) and light diesel oil are sequentially extracted from bottom to top, and gasoline, liquefied gas and dry gas are obtained through separation after a subsequent gas-liquid separator and an absorption stabilizing system. The product distribution of example 1 can be seen in table 2 below. Also, the properties of the highly aromatic oil obtained in example 1 are shown in table 2 below.

Examples 2 to 3

The preparation of the highly aromatic oil was carried out in a similar manner to the procedure described in example 1, following the conditions described in table 2. The product distribution for examples 2-3 can be seen in Table 2 below. Also, the properties of the highly aromatic oil obtained in examples 2 to 3 are shown in Table 2 below.

TABLE 2

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Examples 4 to 7

The preparation of the highly aromatic oil was carried out in a similar manner to the procedure described in example 1, following the conditions described in table 3. The product distributions for examples 4-7 can be found in Table 3 below. Also, the properties of the highly aromatic oil obtained in examples 4 to 7 are shown in Table 3 below.

TABLE 3 Table 3

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Comparative examples 1 to 2

Catalytic cracking/cracking reactions and subsequent fractionation operations were performed in a manner similar to example 1, following the conditions described in table 4 below. The difference is that: comparative examples 1-2 were subjected to cycle oil recovery and the cycle oil extraction plate temperature was lower than the high aromatic oil extraction plate temperature of example 1 without extraction of heavy diesel oil recovery.

The product distribution of comparative examples 1-2 can be seen in Table 4 below. Also, the properties of the slurries prepared in comparative examples 1 to 2 are shown in Table 4 below.

Comparative example 3

Catalytic cracking/cleavage reactions and subsequent fractional distillation operations were carried out in a similar manner to example 1, following the protocol of CN112574777a and the conditions described in table 4 below. The difference is that: comparative example 3 was subjected to cycle oil and slurry oil recovery, and the cycle oil draw-off plate temperature was lower than the high aromatic oil draw-off plate temperature of example 1.

The product distribution of comparative example 3 can be seen in table 4 below.

TABLE 4 Table 4

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Examples 8 to 13

The preparation of the highly aromatic oil was carried out in a similar manner to the procedure described in example 1, following the conditions described in table 5. The product distributions for examples 8-13 can be found in Table 5 below. Also, the properties of the highly aromatic oil obtained in examples 8 to 13 are shown in Table 5 below. In example 13, the fractionator high aromatic oil draw plate temperature was maintained at the baseline temperature, but the amount of additional steam introduced into the reaction oil gas was increased to 45% of the amount of reaction oil gas.

TABLE 5

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Comparative examples 4 to 5

Catalytic cracking/cracking reactions and subsequent fractionation operations were performed in a manner similar to example 1, following the conditions set forth in table 6 below. The difference is that: comparative examples 4-5 were subjected to cycle oil recovery and the cycle oil draw-off plate temperature was lower than the high aromatic draw-off plate temperature of example 1.

The product distributions for comparative examples 4-5 can be found in Table 6 below. Also, the properties of the slurries prepared in comparative examples 4 to 5 are shown in Table 6 below.

Comparative example 6

The paraffin-based catalytic slurry was distilled under reduced pressure at 400℃and 20mmHg on a continuous distillation apparatus according to the method of example CN100549141C, and the distillate was 75% by weight.

TABLE 6

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Application example 1

As can be seen from comparison of the above tables 2, 3, 5 and 7, the highly aromatic oil according to the present invention satisfies the requirements of the raw materials for preparing needle coke.

TABLE 7 requirements for feedstock properties for needle coke

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

The foregoing description is only illustrative of the present invention and is not intended to limit the scope of the invention, 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 invention.

Claims

1. A process for producing a high aromatic hydrocarbon oil, said process comprising:

(4) Extracting liquid oil from a side line of a rectifying tower plate section adjacent to the washing and de-superheating section to obtain the high-aromatic oil, wherein the high-aromatic oil contains ash content <20 mug/g and asphaltene content <1 wt%;

(5) The washing raw oil containing the catalyst powder and extracted from the bottom of the fractionating tower are sent to a catalytic cracking/cracking reactor together with the catalytic cracking/cracking raw oil in the step (1) to carry out catalytic cracking/cracking reaction to generate oil gas; and

(6) Repeating steps (2) - (5) to form a cycle;

wherein greater than or equal to 97 wt% of the oil gas enters a draw-out plate of the high aromatic hydrocarbon oil;

the residual catalytic cracking/cracking raw oil with the weight percent of more than or equal to 1 percent is selected from one or a combination of a plurality of straight-run normal pressure residual oil, straight-run vacuum residual oil, hydrogenated normal pressure residual oil, hydrogenated vacuum residual oil, deasphalted oil and heavy crude oil.

2. The method of claim 1 wherein greater than or equal to 99 wt.% of said oil and gas enters a draw plate of said high aromatic hydrocarbon oil.

3. The process of claims 1 and 2 wherein the high aromatic oil extraction plate temperature is 1-150 ℃ higher than the cycle oil extraction plate temperature; and/or

The oil gas entering the high aromatic hydrocarbon oil extraction plate contains additional low molecular gas; wherein the temperature of the recycle oil extraction plate refers to the temperature of the recycle oil extraction plate in the existing catalytic cracking/cracking fractionating tower, which is 310-330 ℃.

4. A method according to claim 3, wherein the low molecular gas is selected from one or more combinations of water vapour, a hydrocarbon compound or mixture having a boiling point lower than that of a highly aromatic oil, or an oxygen-containing organic matter; or the low molecular gas is added from any position below the high aromatic hydrocarbon oil extraction plate of the catalytic cracking/cracking reaction unit and the fractionating tower.

5. The process of claim 1 wherein greater than or equal to 1 wt.% of the remaining catalytic cracking/cracking feedstock is introduced into the catalytic cracking/cracking fractionation column above, below, or both the wash-off superheat section; or (b)

Part of the washing raw oil containing the eluted catalyst powder in the step (2) is cooled by heat exchange and then recycled to the upper part or the upper part and the lower part of the washing and desorbing superheating section; the other part of the washing raw oil and the catalytic cracking/cracking raw oil in the step (1) are sent together to a catalytic cracking/cracking reactor containing a catalyst to carry out catalytic cracking/cracking reaction; or (b)

In the catalytic cracking/pyrolysis fractionating tower, the washing and superheating section comprises 6-20 layers of herringbone baffles or regular grid fillers; the rectification column plate section comprises 26-50 layers of column plates and has 1-4 circulation reflux in the rectification column plate section; in the catalytic cracking/cracking fractionating tower, high aromatic hydrocarbon oil and diesel oil are sequentially pumped from bottom to top, and gasoline, liquefied gas and dry gas are obtained through separation after a subsequent gas-liquid separator and an absorption stabilizing system.

6. The method according to claim 5, wherein the diesel oil is separated into light diesel oil and heavy diesel oil, and the heavy diesel oil and the light diesel oil are sequentially extracted from bottom to top in the catalytic cracking/pyrolysis fractionation tower, wherein the heavy diesel oil is recycled to the catalytic cracking/pyrolysis reactor containing the catalyst to perform the catalytic cracking/pyrolysis reaction, or is output as a product.

7. The method of claim 1, wherein the less than or equal to 99 wt% of the catalytic cracking/cracking feedstock in step (1) is selected from one or more of straight run wax oil, straight run atmospheric residue, straight run vacuum residue, hydrogenated wax oil, hydrogenated atmospheric residue, hydrogenated vacuum residue, coker wax oil, coker hydrogenated wax oil, deasphalted oil, shale oil, tar sand oil, heavy crude oil, poor diesel oil, animal oil, vegetable oil, and synthetic oil; the catalytic cracking/cracking reactor comprises coaxial or high-low parallel type; or (b)

The catalyst is selected from one or a combination of a plurality of bonding type Y, ZSM-5, beta molecular sieve and composite type catalyst thereof, and in-situ crystallization Y-type catalyst; or (b)

The reaction temperature of the catalytic cracking/cracking reaction is 480-650 ℃, the pressure is 0.1-0.5 Mpa, the regeneration temperature of the catalyst is 650-780 ℃, and the mass ratio of the catalyst to the catalytic cracking/cracking raw oil is 2-10.

8. The method of claim 7, wherein the catalyst further comprises one or both of a propylene aid and an octane aid.

9. The method of claim 1 wherein the high aromatic hydrocarbon oil comprises at least 45 wt% total aromatic hydrocarbons, asphaltenes<1 wt%, sulfur content<0.5 wt%, 20

Density of->

1.03g/cm ³ And ash content<20μg/g。

10. The high aromatic hydrocarbon oil produced by the process of any one of claims 1-9, comprising ash<20. Mu.g/g; or the high aromatic oil comprises at least 45 wt% total aromatics, asphaltenes<1 wt%, sulfur content<0.5 wt%, 20

Density->

1.03g/cm ³ And ash content<20μg/g。

11. The use of the highly aromatic oil of claim 10 for the preparation of needle coke, carbon fiber, carbon black, rubber softeners and fillers, petroleum aromatic plasticizers, heat transfer oils, petroleum sulfonate surfactants, blend fuel oils, hydrotreated feedstock.