CN105802663A - Method and device for converting catalytic cracking cycle oil in classified and divisional manner - Google Patents

Abstract

The invention provides a method and a device for converting catalytic cracking cycle oil in stages and zones. Wherein, the device comprises a settler (1), a regenerator (2), a first riser reactor (31), a second riser reactor (32), a catalytic hydrogenation unit (4) and a fractionation unit (5 ), the regenerator is arranged at the bottom of the settler, the first riser reactor and the second riser reactor are arranged in parallel, and the tops of the two riser reactors are respectively connected with the gas-solid separation device (11) in the settler, and the two The bottom of each riser reactor is connected with the bottom of the regenerator through the first inclined pipe (61) and the second inclined pipe (62) respectively, the top of the settler is connected with the fractionation unit, and the fractionation unit is connected with the catalytic hydrogenation unit; The tube reactor (31) is provided with a raw oil inlet (34), and the second riser reactor (32) is provided with a circulating oil inlet (35), which is connected with the circulating oil outlet (41) of the catalytic hydrogenation unit.

Description

A method and device for converting catalytic cracking cycle oil by classification and partition

technical field

The invention relates to the field of petroleum product processing, in particular to a method and device for converting catalytic cracking circulating oil in stages and partitions.

Background technique

Catalytic cracking cycle oil is an important by-product of catalytic cracking. It is large in quantity and rich in aromatics, especially polycyclic aromatic hydrocarbons. Circulation conversion in catalytic cracking unit.

However, since January 2015, China will implement the National IV emission standard, requiring that the mass fraction of polycyclic aromatic hydrocarbons in vehicle diesel should not exceed 11%, and FCC light cycle oil as a diesel blending component is subject to greater restrictions. Although refining technology has made great progress and innovation in recent years, there is still no better breakthrough in the processing technology of catalytic cracking light cycle oil (LCO), a by-product of refinery with special properties. How to realize the efficient conversion of catalytic cracking light cycle oil and make it into high value-added products is a difficult problem for refineries.

For catalytic cracking light cycle oil, the conventional processing method is to use hydrogenation process to saturate aromatic hydrocarbons and remove heteroatoms, so as to realize the refining of catalytic cracking light cycle oil and produce ultra-low sulfur diesel oil. For example, CN201110325356 and CN201110325408 proposed a method for selective hydrofining of light cycle oil. After the reaction of this method, naphthalene bicyclic aromatic hydrocarbons and condensed ring aromatic hydrocarbons in the oil are partially saturated or ring-opened, and the conversion rate of polycyclic aromatic hydrocarbons only reaches more than 30.0%. The retention rate of the total aromatics in the product is greater than 96.0%, the hydrogen consumption is high and the cetane number increases little.

Some researchers (New technology of LCO hydrogenation to produce high value-added products. Wang Dehui, Xu Xingang, Liu Ruiping, Miao Xiping. Refining Technology and Engineering, 2014,44(7):11-14) summarized the new catalytic cracking light cycle oil Hydrogen technology, such as LCO Unicracking process, RLG technology, LCO-X process, etc., these technologies are characterized by the combination of hydrofinishing and hydrocracking to convert catalytic cracking light cycle oil into high-quality diesel oil, single-ring aromatics (benzene, Toluene, xylene and other components) remain in the gasoline fraction as high-quality high-octane components or as light aromatic products. Although this type of technology has greatly improved the cetane number of diesel oil, it still cannot meet the requirements of National IV diesel oil specifications, and has the disadvantages of low total liquid yield and high chemical hydrogen consumption.

For catalytic cracking heavy cycle oil, the conventional processing method is to carry out circular conversion inside the catalytic cracking unit, that is, the cracked refined oil from the fractionating tower is mixed with fresh raw materials into the catalytic riser reactor for conversion, and the amount of refining is affected by the process product structure and processing load constraints. In addition, the conversion rate of the re-refined oil is low, resulting in a high yield of catalytic oil slurry, which affects the yield of light hydrocarbons in the unit.

The hydrocarbon composition in catalytic cracking cycle oil includes paraffins, naphthenes (containing a small amount of olefins) and aromatics. With the difference of catalytic cracking feedstock oil and different operating severity, the hydrocarbon composition of cycle oil varies greatly, but aromatics are the same. Main components, the general mass fraction is greater than 70%, and sometimes reaches about 90%. Among aromatic hydrocarbons, single-ring aromatic hydrocarbons include alkylbenzenes, indanes, tetrahydronaphthalenes and indenes, accounting for about 33% of the total aromatics; polycyclic aromatic hydrocarbons include naphthalenes, acenaphthenes, acenaphthylenes, phenanthrenes and anthracene Aromatics, etc., account for about 67% of the total amount of aromatics. Since the aromatic ring structure cannot undergo ring-opening cracking reaction under catalytic cracking reaction conditions, the conversion efficiency of this part of circulating oil entering the catalytic cracking reactor is very low.

Under catalytic cracking reaction conditions, although polycyclic aromatic hydrocarbons are difficult to ring-opening cracking, under hydro-upgrading conditions, polycyclic aromatic hydrocarbons are relatively easy to be saturated into alkyl aromatic hydrocarbons and cyclohydrocarbyl aromatic hydrocarbons (indanes, tetrahydronaphthalenes and indenes). Class), etc., aromatic hydrocarbons with this structure can be cracked into high-octane gasoline fractions and light hydrocarbons under catalytic cracking conditions. At the same time, in order to reduce the side reaction (such as hydrogen transfer reaction) of cycloalkane aromatic hydrocarbons into polycyclic aromatic hydrocarbons, the effect after the hydrogenation link is not brought into play. Catalysts with ring cracking ability, such as Y-type molecular sieve catalysts rich in β-cage structure.

For the hydro-upgrading reaction of catalytic cracking cycle oil, it is necessary to use a hydrogenation catalyst with high aromatic saturation activity, and control the appropriate reaction conditions to avoid the ring-opening cracking of polycyclic aromatic hydrocarbons, reduce hydrogen consumption and gas product generation. The mass fraction of single-ring aromatics in FCC cycle oil after moderate hydrogenation is significantly higher than that before hydrotreatment, and the mass fraction of cyclohydrocarbylbenzene increases significantly, which provides a basis for FCC cycle oil to re-enter the FCC unit for cracking. Since the cracking reaction of cycloalkyl aromatics is undertaken by the catalytic cracking unit, the low hydrogen consumption and high liquid product yield of the hydrogenation unit are effectively realized.

Comparing the hydrogenated catalytic cracking cycle oil and the heavy raw material processed by the catalytic cracking unit, the molecular structure and cracking performance of the two are still quite different. There are a large number of molecular groups that have not undergone primary cracking in the heavy raw materials, and there are more easily cracked alkyl long chain structures in the molecular groups, which belong to the easily cracked raw materials. The catalytic cracking cycle oil after hydrogenation is rich in alkylaromatics and cyclohydrocarbylaromatics, which is a difficult-to-crack raw material compared with heavy raw materials. Therefore, in order to avoid the mutual interference of the two raw materials with different properties in the catalytic cracking reactor, the two raw materials should be fed in stages to create conditions for optimizing their respective reaction environments.

To sum up, using the two reaction units of catalytic cracking and hydro-upgrading, the cycle oil of the catalytic cracking unit is re-entered into the catalytic cracking unit for cracking after hydrogenation and upgrading using a hydrogenation catalyst with high aromatics saturation activity. The staged feeding of heavy raw materials in the riser reactor can be achieved under the conditions of low hydrogen consumption and virtually no loss of liquid products by matching suitable reaction conditions and using catalysts with significant ring-opening cracking capabilities of naphthenic ring structures. The catalytic cracking cycle oil is converted into a high-octane gasoline fraction, and the gasoline yield is greatly increased.

Contents of the invention

One object of the present invention is to provide a device for converting catalytic cracking cycle oil in stages and zones.

Another object of the present invention is to provide a method for converting catalytic cracking cycle oil in stages and zones. Aiming at the characteristics of high aromatics content and difficult conversion in the circulating oil of the catalytic cracking unit, the present invention proposes a stepwise feeding and reaction of heavy raw material oil and circulating oil on the riser reactor according to the degree of cracking difficulty of the raw material, and The hydrogenation unit is used to set up the cycle oil upgrading link to improve its cracking performance, realize the full cracking of the cycle oil in the catalytic cracking unit, and greatly increase the yield of gasoline fractions and light hydrocarbons.

In order to achieve the above object, on the one hand, the present invention provides a device for converting catalytic cracking cycle oil in different stages, wherein the device includes a settler 1, a regenerator 2, a first riser reactor 31, a second riser Reactor 32, catalytic hydrogenation unit 4 and fractionation unit 5, wherein regenerator 2 is arranged at the bottom of settler 1, first riser reactor 31 and second riser reactor 32 are arranged in parallel, and the two riser reactors react The top of the device 31 is respectively connected with the gas-solid separation device 11 in the settler, the bottoms of the two riser reactors are respectively connected with the bottom of the regenerator 2 through the first inclined pipe 61 and the second inclined pipe 62, and the top of the settler 1 is connected with the fractionation device 5 is connected, the fractionation unit 5 is connected with the catalytic hydrogenation unit 4 so that the light cycle oil and the heavy cycle oil from the fractionation unit 5 can be combined and then enter the catalytic hydrogenation unit 4; the raw material is set in the first riser reactor 31 An oil inlet 34, a circulating oil inlet 35 is provided in the second riser reactor 32, and the circulating oil inlet 35 is connected with the circulating oil outlet 41 of the catalytic hydrogenation unit.

Wherein the settler, regenerator, riser reactor and gas-solid separation device of the present invention are all existing equipment, the present invention is to increase a second riser reaction parallel with the original riser reactor on the basis of existing equipment device.

The raw oil inlet 34, that is, the position where the heavy raw oil enters the riser reactor is consistent with the raw oil inlet of the conventional riser reactor, for example, it is located at the lower part of the first riser reactor 31, and in the first inclined pipe 61 The upper part where it connects with the first riser reactor 31.

In this way, the feedstock oil entering the first riser reactor 31 can contact the catalyst that enters the first riser reactor from the first inclined pipe and ascends to carry out catalytic cracking reaction.

And the circulating oil inlet 35, that is, the position where the circulating oil enters the second riser reactor 32 is consistent with the feed oil inlet of the conventional riser reactor, for example, it is located at the bottom of the second riser reactor 32, and at the second inclined The upper part where the pipe 62 connects with the second riser reactor 32 .

It can be understood that the structure of the first riser reactor and the second riser reactor itself has not been improved, and existing conventional riser reactors can be used in the present invention.

Wherein it can be understood that the gas-solid separation device 11 connected to the riser reactor can be one or two;

That is to say, the tops of the two riser reactors 31 are respectively connected to the same gas-solid separation device 11 in the settler, or are respectively connected to two parallel gas-solid separation devices 11 .

When there is one gas-solid separation device 11, it means that the first riser reactor and the second riser reactor share one gas-solid separation device 11;

When there are two gas-solid separation devices 11, it means that the first riser reactor and the second riser reactor are respectively connected with mutually independent gas-solid separation devices;

For convenience of labeling, the two gas-solid separation devices can be represented by the same reference number 11 .

According to some specific embodiments of the present invention, wherein, the gas-solid separation device 11 includes a first gas-solid separation device 11' and a second gas-solid separation device 11", wherein the top of the first riser reactor 31 is connected to the first gas-solid separation device The separation device 11' is connected, and the top of the second riser reactor 32 is connected with the second gas-solid separation device 11".

Described fractionation device can adopt prior art conventional fractionation device, and according to some specific embodiments of the present invention, wherein, described fractionation device comprises fractionation tower 51, oil-gas separation tank 52, the first stripper 53, the second gas stripper The stripping tower 54 and the refining tank 55, the top of the settler 1 is connected to the bottom of the fractionating tower, the oil-gas separation tank is connected to the top of the fractionating tower, and the first stripping tower, the second stripping tower and the refining tank are arranged from top to bottom The sequence is respectively connected with the fractionation tower.

According to some specific embodiments of the present invention, wherein, the oil slurry outlet 511 is arranged at the bottom of the fractionating tower, and the oil slurry outlet is connected with a port of the four-way pipe 57 through the first heat exchange device 561, and the remaining three ports of the four-way pipe are connected with the fractionation pipe respectively. The tower, the second heat exchange device 562, and the oil slurry outlet 58 are connected, and the second heat exchange device 562 is connected with the fractionation tower.

According to some specific embodiments of the present invention, the oil-gas separation tank 52 is provided with a cracked gas outlet 521 and a liquid fraction outlet 522 of the separation tank.

According to some specific embodiments of the present invention, wherein the liquid fraction outlet 522 of the separation tank is provided with a three-way pipe 523, one of the outlets of the three-way pipe is connected to the fractionation tower 51, so as to lead part of the liquid fraction of the separation tank back into the fractionation tower.

According to some specific embodiments of the present invention, the other outlet of the three-way pipe 523 provided at the liquid fraction outlet 522 of the separation tank is a discharge port.

It can be understood that among the three outlets of the tee pipe 523 described here, one outlet is connected to the liquid fraction outlet 522 of the separation tank, one outlet is connected to the fractionation tower 51, and the third outlet is a discharge port.

According to some specific embodiments of the present invention, wherein, the first stripping column 53 is provided with a first stripping column oil gas inlet 531 to be connected with the fractionation column 51, and a first stripping column liquid fraction outlet 532 is provided, and a first stripping column liquid fraction outlet 532 is provided at the top Stripping tower gas outlet 533 is also connected with fractionating tower; The gas outlet 543 of the second stripping tower is connected with the fractionation tower.

According to some specific embodiments of the present invention, wherein the oil refinery tank 55 is provided with an oil gas inlet 551 to be connected with the fractionation tower 51 , and is provided with a liquid fraction outlet 552 of the oil refinery tank.

According to some specific embodiments of the present invention, wherein, the return oil refinery tank liquid fraction outlet 552 is provided with the return oil refinery tank tee pipe 553, and one of the outlets of the return oil refinery tank tee pipe is connected with the fractionation tower, so that part of the return oil refinery tank The liquid fraction in the tank is led back into the fractionating tower, and the other outlet of the tee pipe back to the refinery tank is connected to the catalytic hydrogenation unit 4 after converging with the liquid fraction outlet 542 of the second stripping tower through pipelines.

Wherein it can be understood that among the three outlets of the oil refining tank tee pipe 553 described here, one outlet is connected with the liquid fraction outlet 552 of the oil refining tank, one outlet is connected with the fractionation tower 51, and the third outlet The outlet 542 of the liquid fraction of the second stripping column is connected to the catalytic hydrogenation device 4 after converging through pipelines.

According to some specific embodiments of the present invention, wherein, the catalytic hydrogenation unit 4 includes a catalytic hydrogenation unit 42 and a separation unit 43, the fractionation unit 5 is connected to the top of the catalytic hydrogenation unit, and the bottom of the catalytic hydrogenation unit is connected to the separation unit. The separation device is connected to the circulating oil inlet 35 of the riser reactor 3 .

On the other hand, the present invention also provides a method for fractional conversion of catalytic cracking cycle oil, wherein the method comprises that heavy raw oil undergoes a catalytic cracking reaction of raw material oil in the presence of a catalyst in a riser reactor to obtain The reaction oil gas enters the fractionation device and undergoes fractionation to obtain light cycle oil and heavy cycle oil. After the light cycle oil and heavy cycle oil are combined, catalytic hydrogenation reaction is carried out, and the obtained cycle oil is combined with the regenerated catalytic cracking reaction catalyst After mixing, the catalytic cracking reaction of circulating oil is carried out, in which the catalytic cracking reaction of circulating oil and the catalytic cracking reaction of feedstock oil are carried out in two independent riser reactors set up in parallel respectively; the catalytic cracking reaction of circulating oil and the catalytic cracking reaction of feedstock oil The reaction oil gas obtained by the reaction is recycled into the fractionation device for fractionation to obtain light cycle oil and heavy cycle oil.

Wherein said catalyzer can use the conventional catalyzer of this field, those skilled in the art selects in existing catalyzer need not pay more creative work; And according to some specific embodiments of the present invention, described catalyst active component is tungsten, nickel, Combination of two or three metals in molybdenum, wherein based on the total weight of the catalyst, tungsten 10-30%, molybdenum 1-10%, nickel 5-15%; the balance is the carrier of alumina and silicon oxide.

According to some specific embodiments of the present invention, wherein, the catalytic cracking reaction conditions of the feedstock oil are: reaction temperature 470-550°C, solvent-oil ratio 5-9, reaction time 1.5-3.5s, water-oil ratio 0.03-0.10;

According to some specific embodiments of the present invention, the reaction conditions for catalytic cracking of feedstock oil further include: feedstock preheating temperature of 150-300°C.

According to some specific embodiments of the present invention, wherein the catalytic hydrogenation reaction conditions are: hydrogen partial pressure 6.0-12.0MPa, reaction temperature 300-400°C, hydrogen-oil volume ratio 300-1000v/v, volume space velocity 0.5- 3.0h ^-1 .

According to some specific embodiments of the present invention, wherein, the catalytic cracking reaction conditions of the circulating oil are: reaction temperature 520-600°C, catalyst-oil ratio 7-20, reaction time 0.6-3.0s, water-oil ratio 0.01-0.06.

According to some specific embodiments of the present invention, wherein, the catalytic cracking reaction conditions of the circulating oil further include: a raw material preheating temperature of 150-300°C.

According to some specific embodiments of the present invention, wherein, the weight content of hydrogen in the distillate obtained by combining the light cycle oil and the heavy cycle oil and performing catalytic hydrogenation reaction is 11.5-14.5%.

According to some specific embodiments of the present invention, wherein, the method is performed using any one of the devices described above in the present invention.

According to some specific embodiments of the present invention, wherein, the method comprises, heavy stock oil is sent into the first riser reactor 31 by stock oil inlet 34 and reacts under the condition that catalyst exists, and reaction mixture is in settler 1 Separation, the catalyst settles into the regenerator 2 for regeneration, and returns to the first riser reactor through the first inclined pipe 61 provided at the bottom of the regenerator, and the oil gas enters the fractionation device 5 from the top of the settler, and the light obtained through fractionation The combined circulating oil and heavy circulating oil enter the catalytic hydrogenation unit 4 for catalytic hydrogenation reaction, and the obtained circulating oil is transported to the second riser reactor 32, where it is mixed with the catalyst and then undergoes catalytic cracking reaction of the circulating oil. Reaction and catalytic cracking of raw oil The reaction oil gas obtained from the catalytic cracking reaction is recycled into the fractionation device for fractionation to obtain light cycle oil and heavy cycle oil.

According to some specific embodiments of the present invention, wherein, the oil gas enters the bottom of the fractionating tower from the top of the settler, and undergoes fractionation in the fractionating tower to obtain fractionated oil and gas at the top of the fractionating tower, and passes through the first stripping tower in the middle of the fractionating tower to obtain the light diesel oil fraction. The light cycle oil is obtained from the second stripping tower, the heavy cycle oil is obtained through the oil refining tank, and the oil slurry is obtained at the bottom of the fractionation tower; the fractionated oil gas passes through the oil and gas separation tank to obtain cracked gas and gasoline fractions, and the heavy cycle oil and light cycle oil are combined Then enter the catalytic hydrogenation unit.

According to some specific embodiments of the present invention, wherein, after the fractionated oil and gas pass through the oil-gas separation tank to obtain cracked gas and gasoline fraction, part of the gasoline fraction is sent back to the fractionation tower, and the other part is led out of the device.

Wherein the ratio of the portion of the gasoline fraction sent back to the fractionating tower and the portion of the extraction device can be set according to conventional operations in the art, or set according to production needs, and the present invention has no special requirements for this.

According to some specific embodiments of the present invention, a part of the heavy cycle oil obtained through returning to the refining tank is combined with the light cycle oil, and the other part is returned to the fractionation tower.

According to some specific embodiments of the present invention, the weight ratio of the heavy cycle oil returned to the fractionation tower to the heavy cycle oil combined with the light cycle oil is 0-10:1.

It can be understood that when the above ratio is 0:1, it means that all the heavy cycle oil obtained through returning to the oil refining tank is combined with the light cycle oil without returning to the fractionation tower.

To sum up, the present invention provides a method and device for converting catalytic cracking cycle oil in stages and zones. Method of the present invention has following advantage:

Aiming at the characteristics of high aromatics content and difficult conversion in the circulating oil of the catalytic cracking unit, the present invention proposes a method of separately feeding heavy raw material oil and circulating oil in independent riser reactors according to the degree of cracking difficulty of the raw material. reaction to avoid raw materials with large conversion performances interfering with each other in the same reactor; a hydrogenation unit is used to set up a cycle oil upgrading reaction area, and the cycle oil is led out of the catalytic cracking unit for hydrogenation upgrading to increase its hydrogen content and reduce fractions The aromatic hydrocarbon structural groups in the catalytic cracking unit are returned to the circulating oil cracking reaction zone of the catalytic cracking unit for conversion, which effectively reduces the competitive adsorption effect of oil and gas molecules on the active center of the catalyst between the circulating oil and the heavy feedstock oil in the conventional catalytic cracking process. Improve the cracking efficiency of cycle oil and produce gasoline fractions and light hydrocarbons to the maximum.

Description of drawings

Fig. 1 is the schematic diagram of the device of embodiment 1;

Fig. 2 is the schematic diagram of the fractionation device of embodiment 1.

detailed description

The implementation process and beneficial effects of the present invention are described in detail below through specific examples, aiming to help readers better understand the essence and characteristics of the present invention, and not as a limitation to the scope of implementation of this case.

Example 1

Device and flow process of the present invention can be seen Fig. 1 and Fig. 2, briefly describe as follows: device comprises settler 1, regenerator 2, the first riser reactor 31, the second riser reactor 32, catalytic hydrogenation unit 4 and fractionation Device 5, wherein the regenerator is arranged at the bottom of the settler, the first riser reactor and the second riser reactor are arranged in parallel, and the tops of the two riser reactors are connected with the two gas-solid separation devices 11 in the settler respectively. ' and 11" are connected, the bottoms of the two riser reactors are respectively connected to the bottom of the regenerator through the first inclined pipe 61 and the second inclined pipe 62, the top of the settler is connected to the fractionation unit, and the fractionation unit is connected to the catalytic hydrogenation unit so that The light cycle oil and the heavy cycle oil coming out from the fractionation unit can be combined and then enter the catalytic hydrogenation unit; a raw oil inlet 34 is set in the first riser reactor 31, and a cycle oil inlet 35 is set in the second riser reactor 32 , and is connected with the circulating oil outlet 41 of the catalytic hydrogenation unit, wherein the feedstock oil inlet and the circulating oil inlet are respectively arranged at the lower part of the first and second riser reactors, and are located at the first inclined pipe and the second inclined pipe respectively connected with Above the junction of the first riser reactor and the second riser reactor. The processing conditions (catalytic cracking of feedstock oil) in the first riser reaction zone are: 500°C of reaction temperature, 6.5 agent-oil ratio, 3.0s reaction times, The raw material preheating temperature is 240°C, and the water-oil ratio is 0.06.

The oil and gas generated in the first riser reactor and the catalyst are separated through the first gas-solid separation device 11' installed in the settler 1, and the catalyst enters the stripping section 12 through the settler 1, and enters the regenerator 2 after stripping Regeneration: the regenerated catalyst returns to the bottom of the first riser reactor 31 and the second riser reactor 32 through the first inclined pipe 61 and the second inclined pipe 62 for recycling. The reaction oil gas coming out from the top of the settler 1 enters the bottom of the fractionation tower 51 to separate components. The oil gas at the top of the tower enters the oil-gas separation tank 52 after being condensed and cooled, and the cracked gas is drawn from the upper part, and the gasoline is drawn from the lower part. The light cycle oil is drawn after stripping by the second stripping tower 54; the heavy cycle oil fraction (returning oil) passes through the rear part of the refining oil tank 55 to return to the fractionation tower, and a part of the heavy cycle oil is drawn and mixed with the light cycle oil and then enters the catalyst Hydrogenation reaction device 42, wherein the ratio of the part of the heavy cycle oil returning to the fractionation tower and the part mixed with the light cycle oil is 1:1; part of the oil slurry obtained at the bottom of the fractionation tower returns to the fractionation tower after heat exchange, and part of the oil slurry Extraction device.

The light cycle oil and the heavy cycle oil are extracted separately and mixed, and then enter the catalytic hydrogenation reaction device 42. Under the action of hydrogen and catalyst, controllable modification reactions such as hydrogenation and saturation of polycyclic aromatic rings occur. The technological conditions of catalytic hydrogenation upgrading are: hydrogen partial pressure 8.0MPa, reaction temperature 360℃, hydrogen-oil volume ratio 600v/v, volume space velocity 1.2h ^-1 . Wherein, the weight content of hydrogen in the fraction oil obtained by combining the light cycle oil and the heavy cycle oil and carrying out the catalytic hydrogenation reaction is 12.4%. Afterwards, the reaction oil gas enters the separation device 43, and the gas components and the gasoline fraction extraction device are separated. The circulating oil after catalytic hydrogenation passes through the heat exchange device 563 and then enters the second riser reactor through the circulating oil inlet 35, and contacts with the regenerated catalyst from the regenerator 2 to perform catalytic cracking reaction. The reaction oil gas and catalyst flow upward into the settler 1, and the oil gas and catalyst are separated by the second gas-solid separation device 11" connected thereto. The oil gas (oil gas from the catalytic cracking reaction of circulating oil) from the second riser reactor is combined with the first The oil and gas from a riser reactor (the oil and gas from the catalytic cracking reaction of raw oil) enters the fractionation unit 5 through the top of the settler 1 for fractionation and then enters the catalytic hydrogenation unit 4 for catalytic hydrogenation. Among them, the catalytic cracking of circulating oil The technological conditions of the reaction are as follows: reaction temperature 550°C, agent-oil ratio 10, reaction time 2.0s, water-oil ratio 0.04, raw material preheating temperature 260°C.

In order to verify the effect of the present invention, the above-mentioned technical process was adopted to carry out an experiment on a catalytic cracking and hydro-upgrading unit of a certain refinery, and the test results are shown in the table below.

A certain heavy crude oil and its catalytic cycle oil (properties are shown in Table 1). After adopting the invention, the catalytic cycle oil enters the catalytic hydro-upgrading unit for transformation, and the modified catalytic hydro-cycle oil enters the second riser reactor Reacting with the catalyst, the obtained oil gas and the oil gas obtained from the catalytic cracking reaction of raw oil in the first riser reactor enter into the fractionation device 5 through the outlet at the top of the settler. The properties of the catalysts used in each device are shown in Table 2 and Table 3, and the optimized reaction conditions are shown in Table 4. Compared with conventional heavy oil catalytic cracking, the patented technology can increase the yield of gasoline by 21.67 percentage points and the yield of light hydrocarbons by 5.4 percentage points, and the effect of increasing the production of gasoline and light hydrocarbons is remarkable. The detailed product distribution can be seen in Table 5.

Table 1 Properties of heavy feed oil and catalytic cycle oil

project heavy crude oil Catalytic cycle oil Density(20℃)kg/ ^m3 928.1 970.0 Hydrogen content, wt% 12.29 8.9 Carbon content, wt% 86.30 91.0 Sulfur content, wt% 1.0 1.21 Nitrogen content, wt% 0.20 0.07 Hydrocarbon Group Composition Analysis Saturated hydrocarbons, wt% 59.0 8.7 Aromatics, wt% 31.5 91.3 Colloid, wt% 8.9 0.0 Asphaltenes, wt% 0.6 0.0 Carbon residue value, wt% 4.02 Ni content, wt% 8.4 V content, wt% 6.1

Table 2 Properties of catalytic cracking catalysts

project data Microreactivity/% 63 Specific surface area/(m ² /g) 110 Matrix specific surface area/(m ² /g) 47 Micropore specific surface area/(m ² /g) 65 Pore volume/(mL/g) 0.20 Micropore volume/(mL/g) 0.03 Sieve volume composition/% 0～40μm twenty one 0～80μm 70 0～149μm 98 Average particle size/μm 62

Table 3 Properties of Hydrogenation Upgrading Catalyst

project data diameter/mm 1.6 Specific surface area/(m ² /g) 140 shape clover Pore volume/(mL/g) 0.3 Main metal active components Tungsten and Nickel

Table 4 main process conditions

Table 5 Distribution of main products

Product distribution and properties prior art solutions The present invention dry gas 3.52 4.21 liquefied gas 17.85 22.92 gasoline 43.02 64.01 Light diesel oil 22.02 1.21 oil slurry 4.8 1.07 coke 8.79 6.58 total 100.0 100.0

Remarks: For the existing technical solutions in Table 5, please refer to Xu Youhao's "Chemistry and Technology of Catalytic Cracking", Science Press, 2013, p1162-1184.

Example 2

Other conditions remain unchanged, using the process conditions in Table 6, the effects shown in Table 7 can be obtained.

Table 6 main process conditions

Table 7 Distribution of main products

Product distribution and properties prior art solutions The present invention dry gas 3.52 3.25 liquefied gas 17.85 21.47 gasoline 43.02 65.11 Light diesel oil 22.02 2.67 oil slurry 4.8 1.49 coke 8.79 6.01 total 100.0 100.0

Example 3

Other conditions remain unchanged, using the process conditions in Table 8, the effects shown in Table 9 can be obtained.

Table 8 main process conditions

Table 9 Distribution of main products

Product distribution and properties prior art solutions The present invention dry gas 3.52 4.27 liquefied gas 17.85 30.74 gasoline 43.02 55.73 Light diesel oil 22.02 1.03 oil slurry 4.80 1 coke 8.79 7.23 total 100.0 100.0

Claims (10)

1. a kind of device of conversion catalytic cracking circulating oil of graded zone, wherein, said device comprises settler (1), regenerator (2), the first riser reactor (31), the second riser reactor (32 ), a catalytic hydrogenation unit (4) and a fractionation unit (5), wherein the regenerator (2) is arranged at the bottom of the settler (1), the first riser reactor (31) and the second riser reactor (32 ) is set in parallel, the tops of the two riser reactors (31) are respectively connected with the gas-solid separation device (11) in the settler, and the bottoms of the two riser reactors pass through the first inclined pipe (61) and the second inclined pipe respectively. The pipe (62) is connected to the bottom of the regenerator (2), the top of the settler (1) is connected to the fractionation unit (5), and the fractionation unit (5) is connected to the catalytic hydrogenation unit (4) so that The light cycle oil and the heavy cycle oil can enter in the catalytic hydrogenation unit (4) after being able to merge; The raw oil inlet (34) is set in the first riser reactor (31), and in the second riser reactor (32) The circulating oil inlet (35) is set, and the circulating oil inlet (35) is connected with the circulating oil outlet (41) of the catalytic hydrogenation unit; preferably said gas-solid separation device (11) comprises the first gas-solid separation device (11 ') and The second gas-solid separation device (11 "), wherein the top of the first riser reactor (31) is connected with the first gas-solid separation device (11 '), and the top of the second riser reactor (32) is connected with the second gas-solid separation device (11 '). Separator (11") connection. 2. device according to claim 1, wherein, said fractionation unit comprises fractionation column (51), oil-gas separation tank (52), the first stripper (53), the second stripper (54) and return The refinery tank (55), the top of the settler (1) is connected to the bottom of the fractionation tower, the oil-gas separation tank is connected to the top of the fractionation tower, and the first stripping tower, the second stripping tower and the oil refining tank are arranged according to the order from top to bottom The sequence is respectively connected with the fractionation tower. 3. The device according to claim 2, wherein the oil slurry outlet (511) is arranged at the bottom of the fractionating tower, and the oil slurry outlet is connected with a port of the four-way pipe (57) through the first heat exchange device (561), and the four-way The remaining three ports of the pipe are respectively connected with the fractionation tower, the second heat exchange device (562), and the oil slurry outlet (58), and the second heat exchange device (562) is connected with the fractionation tower again. 4. device according to claim 2, wherein, oil-gas separation tank (52) is provided with cracked gas outlet (521) and separation tank liquid fraction outlet (522); Wherein preferred separation tank liquid fraction outlet (522) is provided with three-way pipe (523), one of the outlets of the tee pipe is connected with the fractionation tower (51), so that part of the separation tank liquid fraction is introduced back into the fractionation tower. 5. device according to claim 2, wherein, the first stripper (53) is provided with the first stripper oil gas inlet (531) to be connected with fractionation tower (51), and the first stripper liquid fraction is set Outlet (532), and the first stripping tower gas outlet (533) is set at the top and is connected with fractionation tower; The second stripping tower (54) is provided with the second stripping tower oil gas inlet (541) to be connected with fractionation tower, And the liquid fraction outlet (542) of the second stripping tower is set, and the gas outlet (543) of the second stripping tower is set at the top and connected with the fractionation tower. 6. The device according to claim 2, wherein the oil refinery tank (55) is set back to the refinery tank oil gas inlet (551) to be connected with the fractionation column (51), and the oil refinery tank liquid fraction outlet (552) is set back ); Wherein it is preferred to return to the refinery tank liquid fraction outlet (552) to set the back to the refinery tank tee pipe (553), and return to one of the outlets of the oil refinery tank tee pipe to be connected with the fractionation tower to return part of the oil refinery tank The liquid fraction is led back into the fractionation tower, and the other outlet of the tee pipe back to the refinery tank is connected with the catalytic hydrogenation unit (4) after converging with the liquid fraction outlet (542) of the second stripping tower through pipelines. 7. device according to claim 1, wherein, described catalytic hydrogenation unit (4) comprises catalytic hydrogenation unit (42) and separation unit (43), fractionation unit (5) and catalytic hydrogenation unit top connected, the bottom of the catalytic hydrogenation reaction device is connected with the separation device, and the separation device is connected with the circulating oil inlet (35) of the riser reactor (3). 8. A method for fractional conversion of catalytic cracking cycle oil, wherein the method comprises heavy feed oil in a riser reactor in the presence of a catalyst after the feed oil catalytic cracking reaction, the reaction oil gas obtained enters the fractionation unit and passes through Fractional distillation to obtain light cycle oil and heavy cycle oil, combine the light cycle oil and heavy cycle oil to carry out catalytic hydrogenation reaction, and mix the obtained cycle oil with the regenerated catalytic cracking reaction catalyst mentioned above to carry out cycle oil catalytic cracking reaction, wherein the catalytic cracking reaction of circulating oil and the catalytic cracking reaction of raw oil are respectively carried out in two independent parallel riser reactors; the reaction of catalytic cracking reaction of circulating oil and catalytic cracking reaction of raw oil is carried out Enter the fractionation device for fractionation to obtain light cycle oil and heavy cycle oil; Preferably, the raw material oil catalytic cracking reaction conditions are as follows: reaction temperature 470-550°C, agent-to-oil ratio 5-9, reaction time 1.5-3.5s, water-oil ratio 0.03-0.10; more preferably raw material preheating temperature 150-300 ℃; Preferably, the catalytic hydrogenation reaction conditions are: hydrogen partial pressure 6.0-12.0MPa, reaction temperature 300-400°C, hydrogen-oil volume ratio 300-1000v/v, volume space velocity 0.5-3.0h ^-1 ; Preferably, the catalytic cracking reaction conditions of circulating oil are as follows: reaction temperature 520-600°C, catalyst-to-oil ratio 7-20, reaction time 0.6-3.0s, water-oil ratio 0.01-0.06; more preferably raw material preheating temperature 150-300 ℃; Preferably, the weight content of hydrogen in the fraction oil obtained by combining the light cycle oil and the heavy cycle oil and carrying out catalytic hydrogenation reaction is 11.5-14.5%. 9. The method according to claim 8, wherein, the method is to use the device described in any one of claims 1 to 7 to carry out; preferably the method includes, the heavy stock oil is imported from the stock oil inlet (34) Sent into the first riser reactor (31) to react under the condition of the presence of catalyst, the reaction mixture is separated in the settler (1), and the catalyst settles in the regenerator (2) for regeneration, and passes through the bottom of the regenerator The first inclined pipe (61) returns to the first riser reactor, the oil gas enters the fractionation unit (5) from the top of the settler, and the light cycle oil and heavy cycle oil obtained through fractionation are combined and then enter the catalytic hydrogenation unit (4 ) for catalytic hydrogenation reaction, the obtained circulating oil is transported to the second riser reactor (32), mixed with the catalyst and then subjected to the catalytic cracking reaction of the circulating oil, the reaction oil gas obtained by the catalytic cracking reaction of the circulating oil and the catalytic cracking reaction of the feedstock oil Recycle into the fractionation unit for fractionation to obtain light cycle oil and heavy cycle oil. 10. method according to claim 9, wherein, oil gas enters fractionating tower bottom by settler top, through fractionating tower fractionation, obtains fractionated oil gas at fractionating tower top, obtains light diesel oil through the first stripping tower in fractionating tower middle part Distillate, through the second stripping tower to obtain light cycle oil, through the return oil refining tank to obtain heavy cycle oil, and to obtain oil slurry at the bottom of the fractionation tower; where the fractionated oil and gas pass through the oil and gas separation tank to obtain cracked gas and gasoline fractions, heavy cycle oil and light cycle oil The circulating oil enters the catalytic hydrogenation unit after being combined; Preferably, after the fractionated oil and gas pass through the oil-gas separation tank to obtain cracked gas and gasoline fraction, part of the gasoline fraction is sent back to the fractionation tower, and the other part is drawn out of the device; Preferably, a part of the heavy cycle oil obtained through returning to the refining tank is combined with the light cycle oil, and the other part is returned to the fractionation tower.