CN104560166B - A kind of petroleum hydrocarbon is produced the catalysis conversion method of high-knock rating gasoline - Google Patents

Abstract

A kind of petroleum hydrocarbon is produced the catalysis conversion method of high-knock rating gasoline, catalytic cracking light cycle oil obtains light fraction and heavy distillat through cutting, wherein heavy distillat obtains hydrogenation heavy distillat through hydrotreatment, light fraction, hydrogenation heavy distillat separately enter the secondary riser reactor of catalytic cracking unit, heavy petroleum hydrocarbon enters the main riser reactor of catalytic cracking unit, under catalytic cracking catalyst exists, carry out cracking reaction, reaction product isolated obtains comprising the product of gasoline, light cycle oil. The method enters the layering in secondary riser reactor of the heavy distillat after the light fraction of light cycle oil and hydrogenation, can optimize to greatest extent and meet the required harsh conditions of light cycle oil different fractions catalytic cracking reaction, thereby farthest produce high-octane catalytic gasoline.

Description

A catalytic conversion method for producing high-octane gasoline from petroleum hydrocarbons

technical field

The invention belongs to the catalytic conversion method of petroleum hydrocarbons in the absence of hydrogen, more specifically, a catalytic conversion method for producing high-octane gasoline from heavy petroleum hydrocarbons.

Background technique

With the development of heavy crude oil and the rapid growth of market demand for light oil products, in my country, catalytic cracking technology, which is used to lighten heavy oil, has developed rapidly. However, a fact that must be faced is that the quality of catalytic cracking diesel oil (or "light cycle oil") has always been relatively poor, with high density, high aromatic content, and low cetane number. It is also difficult to meet increasingly stringent diesel specifications. How to solve the catalytic cracking light cycle oil is an increasingly serious problem. Another problem that exists at the same time is the long-term shortage of domestic finished gasoline, and catalytic cracking gasoline accounts for 80% of finished gasoline. Therefore, how to maximize the production of high-octane gasoline from heavy feedstock without producing light cycle oil through catalytic cracking technology may be a new way to solve the above problems.

US4585545 discloses a catalytic conversion method in which the whole distillate of catalytically cracked light cycle oil is firstly subjected to hydrotreating, and the obtained hydrogenated diesel oil is subjected to catalytic cracking to produce gasoline rich in single-ring aromatic hydrocarbons.

CN1422327A discloses a method for upgrading light cycle oil by catalytic cracking, which is to deeply hydrogenate the light cycle oil produced by the first catalytic cracking unit with heavy oil as raw material, and then enter the second catalytic cracking oil to obtain the hydrogenated cycle oil cracking unit. On the basis of this method, CN1423689A emphasizes that the catalyst in the second catalytic cracking unit requires 50-95% shape-selective zeolite and about 5-50% large-pore zeolite with a pore diameter greater than or equal to about 0.7nm to selectively improve Light olefin yields.

CN1466619A discloses a conversion method of catalytic cracking light cycle oil, which is to divide the catalytic cracking riser reactor into two reaction zones, upstream and downstream, wherein the heavy oil is injected into the downstream zone, and the catalytic cracking product light cycle oil is hydrogenated The hydrotreated cycle oil obtained after treatment is injected into the upstream zone. On the basis of this method, the feed to the downstream zone of the CN1425054A method is added with naphtha in addition to hydrogenated cycle oil. In this method, not only the hydrogen consumption is high, but also the reaction of the hydrogenated cycle oil in the upstream zone will seriously affect the conversion of the downstream heavy oil.

From the literature disclosed above, it can be found that one of the important ways to process catalytic cracked light cycle oil is to firstly carry out hydrotreating and then catalytic cracking. It must be pointed out that, no matter whether the light cycle oil is hydrogenated or not, compared with the macromolecules of heavy oil, its molecules are smaller and the bond energy is larger. Therefore, how to control the operating parameters of catalytic cracking is one of the keys to the processing of light cycle oil. At the same time, if the light cycle oil is hydrogenated, the operation control of the hydrogenation process is also one of the keys to the processing of light cycle oil. In addition, in order to maximize the production of high-octane gasoline without producing light cycle oil in the catalytic cracking process of heavy petroleum hydrocarbons, it is necessary to consider how to realize the selective catalytic cracking of heavy petroleum hydrocarbons and light cycle oil.

Contents of the invention

The purpose of the present invention is to provide a catalytic conversion method for maximizing the production of high-octane gasoline from heavy petroleum hydrocarbons on the basis of the prior art.

The catalytic conversion method provided by the invention comprises:

(1) FCC light cycle oil is cut to obtain light fraction and heavy fraction;

(2) The heavy fraction in step (1) is subjected to a hydrotreating reaction in the presence of hydrogen and a hydrotreating catalyst, and the reaction product is separated to obtain a hydrogenated heavy fraction;

(3) The light distillate in step (1) and the hydrogenated heavy distillate in step (2) are layered from bottom to top into the auxiliary riser reactor of the catalytic cracking unit, and the catalytic cracking reaction is carried out in the presence of the catalytic cracking catalyst. Raw catalytic cracking catalyst and reaction oil gas, wherein the reaction oil gas is separated to obtain products including gasoline and light cycle oil;

(4) The heavy petroleum hydrocarbon raw material enters the main riser reactor of the catalytic cracking unit, and the catalytic cracking reaction is carried out in the presence of the catalytic cracking catalyst, and the raw catalytic cracking catalyst and the reaction oil gas are separated, and the reaction oil gas is separated to obtain gasoline, light cycle oil products;

(5) The spent catalytic cracking catalyst described in steps (3) and (4) is stripped and regenerated, and the regenerated catalytic cracking catalyst obtained is returned to the riser reactor for recycling.

The catalytic cracking light cycle oil in the step (1) is selected from the light cycle oil produced by an external catalytic cracking unit or/and the light cycle oil produced by the catalytic cracking unit step (3) of this method, preferably the light cycle oil produced by an external catalytic cracking unit and the light cycle oil produced in step (3) of the catalytic cracking unit of the method. In the above method, the mass ratio of step (3) to the heavy petroleum hydrocarbon feedstock is called the light cycle oil cycle ratio.

The method provided by the invention is specifically as follows:

The catalytic cracking light cycle oil enters a separate fractionation tower for cutting. The cutting temperature is controlled at 250-260°C, preferably 260°C. Heavy fraction at this cut temperature.

The heavy fraction is sent to the hydrotreating device, and the hydrotreating reaction is carried out in the presence of hydrogen and a hydrogenation catalyst. The hydrotreating conditions are: hydrogen partial pressure 5.0-22.0MPa, preferably 8.0-15.0MPa; reaction temperature 330-450°C , preferably 340-380°C; volume space velocity 0.1-10.0 hours ^-1 , hydrogen-oil volume ratio 100-2000Nm ³ /m ³ . The reaction product is separated to obtain a fraction with an initial boiling point > 250° C., preferably > 260° C., or called hydrogenated diesel oil, or hydrogenated heavy fraction. The bicyclic aromatics content in the hydrogenated heavy fraction should be ≤20% by weight, preferably ≤10% by weight.

The active metal component of the hydrogenation catalyst is selected from Group VIB metals and/or Group VIII non-noble metals, and the carrier is selected from any one or more of alumina, silicon dioxide, and amorphous silica-alumina. The Group VIB metal is molybdenum or/and tungsten, and the Group VIII non-noble metal is nickel or/and cobalt. The active metal component is preferably a combination of nickel-tungsten, nickel-tungsten-cobalt, nickel-molybdenum or cobalt-molybdenum.

Part of the high-temperature regenerated catalyst from the regenerator enters the pre-lift section at the bottom of the riser reactor, is lifted by the pre-lift medium, goes up, contacts and reacts with the light fraction, and goes up; then contacts and reacts with the hydrogenated heavy fraction, and the mixture of oil, gas and catalyst goes up, Then contact with heavy petroleum hydrocarbon feedstock and another part of high-temperature regenerated catalyst from the regenerator; after the reaction oil and gas come out of the riser, they finally enter the main fractionation tower and the subsequent absorption and stabilization system for separation. The light cycle oil from the main fractionating tower can enter the newly added light cycle oil fractionating tower for cutting, the light fraction of the light cycle oil obtained by cutting is directly recycled back to the auxiliary riser, and the heavy fraction of the light cycle oil obtained by cutting is subjected to hydrotreating The device is saturated with hydrogenation, and the heavy fraction of light cycle oil after hydrogenation is recycled back to the auxiliary riser.

The light fraction and the hydrotreated heavy fraction of the light cycle oil are preferably separated separately into the secondary riser reactor of the catalytic cracking unit, where the light fraction enters from the lower nozzle (upstream) of the riser, and the hydrotreated heavy fraction enters from the upper nozzle of the riser (downstream) entry. The distance between the upper and lower nozzles is preferably 0.01 to 3 seconds, preferably 0.05 to 1 second, to control the residence time of the reaction oil gas within the distance between the two nozzles. The advantage of layered entry of light distillate and hydrogenated heavy distillate is that it can optimize the reaction conditions of catalytic cracking of different distillates, so as to achieve the maximum conversion.

The reaction conditions of the main riser reactor of the catalytic cracking unit are not particularly limited, such as conventional heavy oil catalytic cracking conditions, the reaction temperature is 450-550°C, the mass ratio of agent to oil is 4-8, the oil-gas residence time is 2-4 seconds, the pressure (absolute pressure ) 0.15-0.4MPa, and the weight ratio of steam to raw material is 0.02-0.08; there is no special restriction on the raw material of the main riser reactor, that is, heavy petroleum hydrocarbons, and conventional heavy raw materials can be used. The heavy petroleum hydrocarbon raw material in step (3) is selected from one of straight-run gas oil, coking gas oil, deasphalted oil, hydrorefined oil, hydrocracking tail oil, vacuum residue, and atmospheric residue or several.

The reaction conditions of the auxiliary riser reactor are as follows: the reaction temperature is 520-650°C, preferably 550-590°C; the agent-oil mass ratio is 5-100, preferably 8-50; the oil-gas residence time is 1-10 seconds, preferably 2-8 seconds ; Pressure (absolute pressure) 0.15 ~ 0.4MPa; The weight ratio of water vapor to raw materials is 0.01 ~ 0.5, preferably 0.02 ~ 0.2.

The equilibrium catalyst activity (MAT) of the catalytic cracking unit is ≥60, preferably ≥62.

The secondary riser reactor in step (3) and the main riser reactor in step (4) are equal-diameter riser reactors or reduced-diameter riser reactors. The auxiliary riser reactor and the main riser reactor can share a set of settler, main fractionation column, absorption stabilization system, stripper, regenerator, or use their own settler, main fractionation column, absorption stabilization system, steam extractor, regenerator.

Catalytic cracking catalysts include zeolites, inorganic oxides and optionally clays. The content of each component is respectively: zeolite 10-50 wt%, inorganic oxide 5-90 wt%, clay 0-70 wt%. Wherein the active component is one, two or more selected from Y, HY, USY or Beta zeolites containing or not containing rare earth.

The advantages of the present invention are:

1. It can completely realize the catalytic cracking of heavy petroleum hydrocarbons without producing light cycle oil.

2. The light cycle oil of the catalytic cracking unit is cut first, and the heavy fraction is dehydrogenated, which can minimize the hydrogen consumption;

3. The main and auxiliary risers of the catalytic cracking unit are used to process heavy petroleum hydrocarbons and light cycle oil respectively, which helps to optimize the operating conditions of the two and realize the maximum conversion of the two.

4. The light fraction of light cycle oil and the heavy fraction after hydrogenation enter in layers in the auxiliary riser reactor, which can maximize the harsh conditions required for the catalytic cracking reaction of different fractions of light cycle oil, thereby maximizing the Produces high-octane catalytic gasoline.

Description of drawings

Fig. 1 is a schematic flow chart of the catalytic conversion method for producing high-octane catalytic gasoline provided by the present invention.

detailed description

The method provided by the present invention will be further described below in conjunction with the accompanying drawings, but the present invention is not limited thereto.

The accompanying drawing is a schematic flow chart of the catalytic conversion method provided by the present invention.

Fig. 1 is a schematic flow diagram of the best embodiment of the present invention, but does not limit the present invention. The shape and size of equipment and pipelines are not limited by the accompanying drawings, but determined according to specific conditions. The descriptions of each number in the accompanying drawings are as follows:

1, 3-5, 7, 13, 15-16, 18-20, and 22 all represent pipelines; 2 is light cycle oil fractionation tower; 6 is hydrotreating unit; 10 is catalytic cracking unit; 8, 9, 21 are Feed nozzle; 11 is the auxiliary riser reactor; 12 is the main riser reactor; 14 is the main fractionation column; 17 is the absorption stabilization system.

The best implementation mode provided by the present invention will be further described below in conjunction with the accompanying drawings.

The heavy petroleum hydrocarbon raw material enters the main riser reactor 12 of the catalytic cracking unit 10 through the nozzle 21 to carry out the catalytic cracking reaction, and the reacted oil gas enters the main fractionation tower 14 through the pipeline 13, and the oil slurry from the main fractionation tower 14 passes through the pipeline 15 as a product Discharging device; the oil gas that comes out from main fractionating tower 14 enters follow-up absorption stabilization system 17 through pipeline 16 and is further separated to obtain product dry gas, liquefied gas and high-octane gasoline, and draws device from pipeline 18,19,20 respectively; The light cycle oil coming out of the fractionating tower 14 enters the light cycle oil fractionating tower 2 through pipelines 22 and 1 for cutting to obtain light fractions ≤ 260°C and heavy fractions > 260°C. Wherein the light fraction of ≤ 260 ℃ enters the lower nozzle 9 of the auxiliary riser reactor 11 of the catalytic cracking reactor 10 through the pipeline 3; and the heavy fraction of > 260 ℃ enters the hydrotreating unit 6 through the pipeline 4, and hydrogen passes through the pipeline 5 at the same time Introduce hydrotreating unit 6. The hydrogenated heavy fraction of the hydrogenated product also enters the upper nozzle 8 of the auxiliary riser reactor 11 of the catalytic cracking reactor 10 through the pipeline 7 . The light distillate and the hydrogenated heavy distillate undergo catalytic cracking reaction in the auxiliary riser reactor in the presence of a cracking catalyst, and the reacted oil gas also enters the main fractionating tower 14 through the pipeline 13 for subsequent separation.

The following examples will further illustrate the present invention, but do not limit the present invention thereby. In the examples, the commercial grade of the hydroprocessing catalyst loaded in the hydroprocessing fixed-bed reactor is RN-32V, the commercial grade of the protective agent is RG-1, and the filling volume ratio of the hydroprocessing catalyst and the protective agent is 95:5, both Produced by Sinopec Catalyst Company.

The physical and chemical properties of the catalyst used in the catalytic cracking unit in Examples and Comparative Examples are shown in Table 1. Its commercial brand is HAC, which is produced by Sinopec Catalyst Company.

The heavy petroleum hydrocarbon feedstock used in Examples and Comparative Examples is a mixed feedstock of 90% by weight straight-run wax oil and 10% by weight vacuum residue, and its properties are listed in Table 2.

Example

This example illustrates the use of the method provided in Figure 1 of the present invention. The distillation range cut-off temperature of the light cycle oil fractionation tower is 250°C.

The heavy fraction of light cycle oil enters the medium-sized hydrotreating unit. The test conditions of hydrotreating are: hydrogen partial pressure 8.0MPa; average bed reaction temperature 360℃, volume space velocity 0.5h- ¹ , hydrogen-to-oil volume ratio 1100Nm ³ /m ³ . The dicyclic aromatics content in the hydrogenated heavy fraction was 8.0% by weight.

The main operating parameters of the catalytic cracking unit are shown in Table 3. The light fraction enters from the lower nozzle of the auxiliary riser, while the hydrogenated heavy fraction enters from the upper nozzle of the auxiliary riser. The distance between the upper and lower nozzles controls the residence time of the reaction oil and gas within the distance between the two nozzles to 0.2 seconds.

comparative example

The catalytic cracking test device in the comparative example has only the main riser and no auxiliary riser. There is also no light cycle oil fractionation tower in the comparative example. In the comparative example, the light cycle oil obtained from the main fractionation tower is directly sent to the hydrogenation unit for whole fraction hydrogenation without cutting, and the hydrogenated light cycle oil and heavy petroleum hydrocarbon feedstock are mixed together and then enter the main riser of the catalytic cracking unit for reaction Reactor. Catalyst is identical with embodiment in the comparative example. See Table 3 for the operating conditions of the catalytic cracking unit in the comparative example.

The distribution of catalytic cracking products, hydrogen consumption and gasoline octane number are shown in Table 4.

Comparing the examples and the comparative examples, it can be found that the examples can significantly reduce the hydrogen consumption in the hydrogenation process, and the hydrogen consumption is reduced from 2.6% to 1.43%; in addition, in the comparative examples, because the circulation ratio of the light cycle oil is 0.29, which is much higher than 0.07 in the embodiment finally leads to higher energy consumption. At the same time, it can also be found that compared with the comparative example, the yield of gasoline in the embodiment increases by more than 9 percentage points, while the yield of dry gas and coke decreases significantly. In addition, it can be found from Table 4 that compared with the comparative example, the gasoline octane number RON of the product in the embodiment increased from 92.1 to 95.8.

Table 1 HAC catalyst properties

Table 2 Raw Oil Properties

Raw oil name mixed ingredients Density (20℃), kg/ ^m3 916.8 freezing point, ℃ 32 Refractive index (70°C) 1.4968 Carbon residue, weight % 2.67 average molecular weight 404 Distillation range, ℃ initial boiling point 294 5% 361 10% 381 30% 422 50% 451 70% 497 Sulfur content, % 1.1 Nitrogen content, % 0.24 Hydrogen content, % 12.6 Metal content, mg/kg Ni 6.6 V 1.2

Table 3 Operating parameters

Table 4

Example comparative example Hydrogen consumption, % 1.43 2.6 Energy consumption, kg standard oil/ton raw material 69 76 Product distribution, weight % dry gas 3.21 5.57 liquefied gas 17.61 22.58 gasoline 65.63 56.47 Light diesel oil 0.00 0.00 heavy oil 4.51 3.11 Coke 9.04 12.27 total 100.00 100.00 gasoline octane number RON 95.8 92.1 MON 85.2 81.6

Claims (15)

1. petroleum hydrocarbon is produced a catalysis conversion method for high-knock rating gasoline, it is characterized in that the partyMethod comprises:

(1) catalytic cracking light cycle oil obtains light fraction and heavy distillat through cutting;

(2) the described heavy distillat of step (1) is carried out hydrogenation under hydrogen and hydrotreating catalyst existenceProcessing reaction, reaction product isolated obtains hydrogenation heavy distillat;

(3) the described light fraction of step (1), the described hydrogenation heavy distillat of step (2) divide from bottom to upLayer enters the secondary riser reactor of catalytic cracking unit, under catalytic cracking catalyst exists, carries out catalysisCracking reaction, separate catalytic cracking catalyst to be generated and reaction oil gas, and wherein reaction oil gas is through separatingTo the product that comprises gasoline, light cycle oil;

(4) heavy crude hydrocarbon feed enters the main riser reactor of catalytic cracking unit, splits in catalysisChange under catalyst existence and carry out catalytic cracking reaction, separate catalytic cracking catalyst to be generated and reaction oil gas,Wherein reaction oil gas is isolated to the product that comprises gasoline, light cycle oil;

(5) step (3), (4) described catalytic cracking catalyst to be generated gained after stripping, regenerationRegeneration catalyzing Cracking catalyst is returned to riser reactor and is recycled.

2. according to the method for claim 1, it is characterized in that the described light cycle oil of step (3) returnsStep (1).

3. according to the method for claim 1, it is characterized in that the cutting temperature of described light cycle oil is250～260℃。

4. according to the method for claim 1, it is characterized in that the described hydrotreatment of described step (2)Condition be hydrogen dividing potential drop 5.0～22.0MPa, 330～450 DEG C of reaction temperatures, volume space velocity 0.1～10.0Hour^-1, hydrogen to oil volume ratio 100～2000Nm³/m³。

5. according to the method for claim 1, it is characterized in that the described hydrotreatment of described step (2)The active metal component of catalyst is selected from group vib metal and/or group VIII base metal, carrierBe selected from aluminium oxide, silica, amorphous aluminum silicide any one or several.

6. according to the method for claim 5, it is characterized in that described group vib metal be molybdenum or/And tungsten, group VIII base metal is that nickel is or/and cobalt.

7. according to the method for claim 5, it is characterized in that described active metal component be selected from nickel-tungsten,The combination of nickel-tungsten-cobalt, nickel-molybdenum or cobalt-molybdenum.

8. according to the method for claim 1, it is characterized in that double ring arene content in hydrogenation heavy distillatBe not more than 20 heavy %.

9. according to the method for claim 1, it is characterized in that the described secondary riser reaction of step (3)Device, the described main riser reactor of step (4) are that isometrical riser reactor or reducing riser are anti-Answer device.

10. according to the method in claim 1, it is characterized in that light fraction and hydrogenation heavy distillat are independentThe secondary riser reactor that separately enters catalytic cracking unit, wherein light fraction is from the lower floor of secondary riserNozzle enters, and hydrogenation heavy distillat enters from the upper strata nozzle of secondary riser.

11. according to the method in claim 10, the distance that it is characterized in that upper and lower layer nozzle withControlling the time of staying of reaction oil gas in two-layer nozzle distance is 0.01～3 second.

12. according to the method in claim 1, it is characterized in that the reaction bar of secondary riser reactorPart is: reaction temperature is 520～650 DEG C, and agent oil quality is than 5～100,1～10 second oil gas time of staying,Pressure 0.15～0.4MPa, the weight ratio of water vapour and raw material is 0.01～0.5, device equilibrium catalystActivity be not less than 60.

13. according to the method in claim 12, it is characterized in that the reaction of secondary riser reactorCondition is: reaction temperature is 550～590 DEG C, and agent oil quality is than 8～50,2～8 seconds oil gas time of staying,The weight ratio of water vapour and raw material is 0.02～0.2, and the activity of device equilibrium catalyst is not less than 62.

14. according to the method for claim 1, it is characterized in that the described catalytic cracking of step (3) urgesAgent comprises zeolite, inorganic oxide and optional clay, and the content of each component is respectively: zeolite10～50 heavy %, the heavy % of inorganic oxide 5～90, the heavy % of clay 0～70, wherein active component is choosingSelf-contained or not containing the one of Y, HY, USY or the Beta zeolite of rare earth, two or more.

15. according to the method for claim 1, it is characterized in that the described heavy petroleum hydrocarbon of step (3)Raw material be selected from straight-run gas oil, wax tailings, deasphalted oil, hydrofined oil, hydrocracking tail oil,One or more in decompression residuum, reduced crude.