CN113930254A

CN113930254A - Method for producing chemical raw material by hydrocracking crude oil

Info

Publication number: CN113930254A
Application number: CN202010610694.6A
Authority: CN
Inventors: 莫昌艺; 任亮; 胡志海; 赵阳; 赵广乐
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2020-06-29
Filing date: 2020-06-29
Publication date: 2022-01-14
Anticipated expiration: 2040-06-29
Also published as: CN113930254B

Abstract

A method for producing chemical raw materials by hydrocracking crude oil comprises the steps of sequentially exchanging heat between the dehydrated and desalted crude oil raw materials and reactant flows, mixing the raw oil raw materials with hydrogen, passing the mixture through a pretreatment reaction zone, a hydrofining reaction zone and a hydrocracking reaction zone in sequence, separating gas and liquid of obtained reaction effluents, feeding the obtained reaction effluents into a fractionating tower, and fractionating the obtained reaction effluents to obtain liquefied gas, naphtha fractions, light catalytic cracking raw materials and heavy catalytic cracking raw materials. The method of the invention can realize the direct production of high-quality chemical raw materials from crude oil.

Description

Method for producing chemical raw material by hydrocracking crude oil

Technical Field

The present invention belongs to a method for producing chemical raw materials by processing crude oil in the presence of hydrogen.

Background

In recent years, the consumption demand of gasoline and diesel oil as automotive fuels in China is slowed down year by year, the market demand of the automotive fuel oil is further reduced under the influence of the development of new energy automobiles using hydrogen energy and electric energy in the future, and meanwhile, the development of national economy brings about the social consumption upgrade, and the consumption demand of olefin and aromatic hydrocarbon which can be used as synthetic monomers of various materials is continuously increased.

When a refinery is divided into fuel oil type, fuel oil-type and whole chemical type refineries, and the conversion from a fuel oil type refinery to a whole chemical type refinery is generally performed according to the ratio of fuel oil products to chemical products, the ratio of chemical products in the product structure of the refinery is gradually increased. In order to meet the market demands of future fuel oil and chemical products, a certain proportion of traditional fuel oil type refineries are transformed into chemical oil refineries, however, under the crude oil processing flow of the existing fuel oil type refineries, the crude oil is generally cut and fractionated into a plurality of narrow fractions and then respectively processed to produce the fuel oil, which brings about insufficient proportion of the crude oil transformed into the chemical raw materials on the one hand, thereby resulting in lower yield of the chemical products in the product structure; on the other hand, in the chemical transformation process of part of devices for producing fuel oil, the risk that the investment cost for device transformation is high or qualified chemical raw materials cannot be produced after transformation exists.

CN101760235A discloses a hydrocracking method for heavy crude oil, in which heavy crude oil with API degree less than 20 is sequentially subjected to hydrogenation protective agent, hydrogenation demetallizing agent, hydrogenation desulfurizing agent I, hydrocracking agent and hydrogenation desulfurizing agent II in the presence of hydrogen, and then is separated to obtain hydrogenated crude oil with increased API degree and reduced viscosity.

CN105358661A and CN109593556A disclose a process and a plant for converting crude oil into petrochemicals with improved propylene yield. The method comprises the steps of firstly, distilling crude oil to generate gas, kerosene and/or gas oil and residual oil, and on one hand, generating LPG and an upgrading effluent through residual oil upgrading; in another aspect, the upgraded effluent is subjected to at least 50% ring opening of aromatic rings with kerosene and gas oil to produce petrochemicals.

CN104093821B discloses a hydrotreating and steam pyrolysis process including hydrogen redistribution and integration of direct processing of crude oil. The process begins by separating the crude oil into light and heavy components, wherein the heavy component is hydrogenated to produce an effluent having a reduced contaminant content, a reduced paraffin content, and a reduced BMCI value, and the heavy fraction hydrogenated effluent and the light component are passed to a steam pyrolysis zone to produce olefins and aromatics chemicals.

CN106103664A discloses an integrated hydrocracking process. In the method, crude oil and a raw material from coking are hydrotreated in a first hydrogenation reaction zone to obtain a material flow which is separated into LPG and a liquid-phase material flow, the liquid-phase material flow enters a second hydrocracking zone to be reacted to generate a BTXE material flow and a material flow containing LPG material flow and residual liquid, and the residual liquid material flow is thermally cracked to generate a coking liquid product and petroleum coke.

Disclosure of Invention

In order to solve the problems of long flow, low yield and poor properties of chemical raw materials produced by crude oil in the prior art, the invention provides a hydrocracking method for directly producing a reforming material and a catalytic cracking raw material from the crude oil.

The invention provides a method for producing chemical raw materials by crude oil hydrocracking, which comprises the following steps of heating a dehydrated and desalted crude oil raw material, sequentially passing through a pretreatment reaction zone, a hydrofining reaction zone and a hydrocracking reaction zone in the presence of hydrogen, carrying out gas-liquid separation on obtained reaction effluent, then feeding the obtained reaction effluent into a fractionating tower, and fractionating to obtain liquefied gas, naphtha fraction, light catalytic cracking raw materials and heavy catalytic cracking raw materials, wherein:

(1) the hydrogenation protective agent and the hydrogenation demetallization agent are filled in the pretreatment reaction zone in a grading way, the demetallization rate of the pretreatment reaction zone is controlled to be not less than 90%, and the deasphalting quality rate is not less than 90%;

(2) a hydrofining reaction zone is filled with a hydrofining catalyst, and the conversion depth of the hydrofining reaction zone is controlled so that the mass fraction of aromatic hydrocarbon in the fraction of more than 350 ℃ in the hydrofining generated oil is not more than 20%;

(3) the hydrocracking reaction zone is filled with a hydrocracking catalyst, and the conversion depth of the hydrocracking reaction zone is controlled to control the conversion rate of the distillate with the temperature of more than 350 ℃ to be 10-50%.

In the invention, the crude oil raw material is one crude oil or is obtained by mixing a plurality of crude oils, and the source of the crude oil is not limited. Preferably, the crude oil raw material has an API (equal or less than 27) and a nitrogen content of not more than 2500. mu.g/g. More preferably, the raw oil raw material has Fe content no more than 40 mu g/g, Ca content no more than 40 mu g/g, Ni content no more than 20 mu g/g, V content no more than 20 mu g/g, carbon residue quality fraction no more than 15% and asphaltene content no more than 5000 mu g/g.

The crude oil raw material is sequentially contacted with a hydrogenation protective agent and a hydrogenation demetallization agent in a pretreatment reaction zone to carry out hydrogenation demetallization and hydrogenation deasphalting reactions, and under the preferable condition, the reaction conditions of the pretreatment reaction zone are as follows: the reaction pressure is 6.0MPa to 20.0MPa, the reaction temperature is 260 ℃ to 420 ℃, and the liquid hourly space velocity is 0.5h^-1～15h^-1The volume ratio of hydrogen to oil is 300-2000.

In a preferred case, the hydrogenation protective agent comprises a carrier and an active metal component, wherein the carrier is alumina, the active metal component is selected from at least one group VIII metal and at least one group VIB metal, the group VIII metal is selected from nickel and/or cobalt, the group VIB metal is selected from molybdenum and/or tungsten, and the group VIII metal content is 0.3 wt% to 5 wt% and the group VIB metal content is 1 wt% to 10 wt% in terms of oxides based on the total weight of the hydrogenation protective agent.

In one preferred embodiment of the invention, at least two or more kinds of hydrogenation protective agents are filled in the pretreatment reaction zone, and the particle size of the hydrogenation protective agents gradually decreases and the mass fraction of the active metal components gradually increases along the flow direction of the reactants.

In a preferred case, the hydrodemetallization agent comprises a carrier and an active metal component, wherein the carrier is alumina, the active metal component is selected from at least one group VIII metal and at least one group VIB metal, the group VIII metal is selected from nickel and/or cobalt, the group VIB metal is selected from molybdenum and/or tungsten, and the group VIII metal content is 1 wt% to 5 wt% and the group VIB metal content is 1 wt% to 15 wt% in terms of oxides based on the total weight of the hydrodemetallization agent.

In one preferred embodiment of the present invention, at least two or more hydrodemetallization agents are filled in the pretreatment reaction zone, and the particle size of the hydrodemetallization agent gradually decreases and the mass fraction of the active metal component gradually increases along the flow direction of the reactants.

In the present invention, the reaction effluent from the pretreatment reaction zone is not separatedThen the obtained product is fed into a hydrogenation refining reaction zone, and is contacted with a hydrogenation refining catalyst to make the above-mentioned materials undergo the reactions of hydrogenation desulfurization, hydrogenation denitrification and partial saturation of aromatic hydrocarbon. In a preferred case, the reaction conditions in the hydrofinishing reaction zone are as follows: the reaction pressure is 6.0MPa to 20.0MPa, the reaction temperature is 280 ℃ to 400 ℃, and the liquid hourly volume space velocity is 0.5h^-1～6h^-1The volume ratio of hydrogen to oil is 300-2000.

In order to obtain high-quality chemical raw materials, the conversion depth of a hydrofining reaction zone is controlled, and preferably, the conversion depth of the hydrofining reaction zone is controlled to control the mass fraction of aromatic hydrocarbon in the distillate with the temperature of more than 350 ℃ in hydrofining product oil to be not more than 16%.

In a preferred case, the hydrofinishing catalyst is at least one catalyst selected from group VIB metals, or at least one catalyst selected from group VIII metals, or a combination thereof, supported on an alumina or/and alumina-silica support. More preferably, the group VIII metal is selected from nickel and/or cobalt, the group VIB metal is selected from molybdenum and/or tungsten, and the content of nickel and/or cobalt is 1 wt% to 15 wt% and the content of molybdenum and/or tungsten is 5 wt% to 40 wt% in terms of oxides based on the total weight of the hydrofining catalyst.

In the invention, a gas-liquid separation device or no gas-liquid separation device can be arranged between the hydrofining reaction zone and the hydrocracking reaction zone. When no gas-liquid separation equipment is arranged, the reaction effluent of the hydrofining reaction zone enters the hydrocracking reaction zone together, and the liquid-phase material of the reaction effluent of the hydrofining reaction zone is hydrofining product oil. Preferably, a gas-liquid separation device is arranged, and the effluent of the hydrofining reaction is subjected to gas-liquid separation to obtain hydrogen-rich gas and hydrofined oil. And the hydrofined oil enters a hydrocracking reaction zone to contact with a hydrocracking catalyst for hydrocracking reaction.

In a preferred case, the hydrocracking reaction zone reaction conditions are: the reaction pressure is 6.0MPa to 20.0MPa, the reaction temperature is 290 ℃ to 420 ℃, and the liquid hourly space velocity is 0.3h^-1～5h^-1The volume ratio of hydrogen to oil is 300-2000;

in order to obtain high-quality chemical raw materials, the conversion depth of a hydrocracking reaction zone is controlled, and the conversion rate of fractions at the temperature of more than 350 ℃ is controlled to be 10-50%.

In the invention, the conversion rate of the fraction at the temperature of more than 350 ℃ is as follows: 100 (mass fraction of fraction at 350 ℃ in raw material-mass fraction of fraction at 350 ℃ in hydrocracked product oil)/mass fraction of fraction at 350 ℃ in raw material

In a preferred case, the hydrocracking catalyst comprises a carrier and an active metal component supported on the carrier, wherein the carrier consists of a heat-resistant inorganic oxide and a Y-type molecular sieve; the heat-resistant inorganic oxide is selected from one or more of silicon oxide, aluminum oxide and amorphous aluminum silicate; the active metal component is selected from at least two metal components of VIB group metals and VIII group metals; based on the whole hydrocracking catalyst, calculated by oxides, 15-35 wt% of VIB group metal, 2-8 wt% of VIII group metal, 3-35 wt% of Y-type molecular sieve and the balance of heat-resistant inorganic oxides.

In one preferred embodiment of the present invention, the post-hydrofining catalyst is filled in the lower part of the hydrocracking reaction zone, and the filling ratio of the hydrocracking catalyst to the post-hydrofining catalyst is 8: 1-15: 1. according to the material flow direction, the oil generated by hydrofining passes through a hydrocracking catalyst and a post-hydrofining catalyst in turn.

In the present invention, the post-hydrotreating catalyst loaded in the lower portion of the hydrocracking reaction zone may be the same as or different from the hydrotreating catalyst loaded in the hydrotreating reaction zone.

In a preferred case, the post-hydrofinishing catalyst is at least one catalyst selected from group VIB metals, or at least one catalyst selected from group VIII metals, or a combination thereof, supported on an alumina or/and alumina-silica support. More preferably, the group VIII metal is selected from nickel and/or cobalt, the group VIB metal is selected from molybdenum and/or tungsten, and the content of nickel and/or cobalt is 1 wt% to 15 wt%, and the content of molybdenum and/or tungsten is 5 wt% to 40 wt%, calculated by oxides, based on the total weight of the post-hydrofining catalyst.

In the invention, the hydrocracking reaction effluent is subjected to gas-liquid separation to obtain hydrogen-rich gas and hydrocracking generated oil, and the hydrocracking generated oil enters a fractionating tower to be fractionated to obtain liquefied gas, naphtha fraction, light catalytic cracking raw material, heavy catalytic cracking raw material and other chemical raw materials. Wherein the cutting point of the naphtha fraction and the light catalytic cracking raw material is 130-160 ℃, and the preferable cutting point is 140 ℃; the cutting point of the light catalytic cracking raw material and the heavy catalytic cracking raw material is 330-380 ℃, and the cutting point is preferably 350 ℃.

The naphtha fraction obtained by the invention has low content of sulfur and nitrogen impurities and high potential content of aromatic hydrocarbon, and is a high-quality reforming raw material.

The catalytic cracking process of the present invention is a process of producing low carbon olefins such as ethylene, propylene, butene, etc. by performing high temperature cracking on petroleum hydrocarbons in the presence of a catalyst, and simultaneously producing light aromatic hydrocarbons, and specifically may be one or more of a catalytic cracking process (DCC process), a catalytic thermal cracking process (CPP process), a process for producing ethylene by direct cracking of heavy oil (HCC process), and other catalytic cracking processes, preferably a catalytic cracking DCC process.

The light catalytic cracking raw material and the heavy catalytic cracking raw material obtained by the method are high-quality raw materials in the catalytic cracking process, the yield of the obtained low-carbon olefin is high, and the product yield is high. Specifically, the light catalytic cracking raw material obtained in the present invention has a hydrogen mass fraction of not less than 13.5%, and a UOP K value of not less than 12. The mass fraction of hydrogen in the raw material for heavy catalytic cracking obtained by the invention is not less than 13.5%.

The inventors of the present invention have found through extensive studies that the higher the hydrogen mass fraction of the catalytic cracking feedstock, the higher the olefin content in the catalytic cracking product. When the mass fraction of hydrogen in the raw material for catalytic cracking is controlled to be not less than 13.5 percent, good catalytic cracking product yield can be obtained. Moreover, the economy of the catalytic cracking device is in positive correlation with the UOP K value of the raw material, generally the UOP K value of the raw material is more than 11.9, so that the catalytic cracking (DCC) device can be ensured to have better economy, and the yield of ethylene, propylene and butylene products of the catalytic cracking device is gradually increased along with the increase of the UOP K value of the raw material, so that the economy of the device is gradually improved.

The UOP K value, also called the characteristic factor K, is calculated by a formula

In the formula, Tv is the volume average boiling point of the raw material, d_15.6The density of the raw material is 15.6 ℃.

The processing method provided by the invention is adopted to produce high-quality chemical raw materials, in particular to produce high-quality light catalytic cracking raw materials in large quantity by a hydrocracking method from crude oil, wherein the light catalytic cracking raw materials meet the conditions that the mass fraction of hydrogen is not less than 13.5 percent and the UOP K value is not less than 12. The high-quality catalytic cracking raw material obtained by the invention satisfies the condition that the hydrogen quality fraction is not less than 13.5 percent, and is also high-quality catalytic cracking raw material. By adopting the high-quality catalytic cracking raw material, the catalytic cracking device can achieve the purpose of improving the yield of the high-value product of the low-carbon olefin.

Detailed Description

The following examples further illustrate the process of the present invention for hydrocracking crude oil to produce primarily premium grade materials, but the invention is not limited thereto.

Comparative example 1-1, example 1-1

The proportion and the examples are used for illustrating the influence effect of different properties of light catalytic cracking raw materials on the product yield of a catalytic cracking device.

The results of two light catalytic cracking feedstocks on a DCC bench test apparatus are shown in table 1.

The catalytic cracking catalyst used is of the commercial brand MMC-2, and is produced by Qilu division of China petrochemical Co.

The reaction conditions of the DCC device were: the reaction temperature is 580 ℃, the catalyst-oil ratio is 12, and the steam injection amount is 25 wt% (based on the raw materials).

As can be seen from the data in Table 1, the two light catalytic cracking raw materials with the same distillation range and different hydrogen contents and UOP K values react under the same catalytic cracking process conditions, the hydrogen mass fraction of the light catalytic cracking raw material 2 is more than 13.5%, and the UOP K value is more than 12, so that higher yield of the low-carbon olefins (ethylene, propylene and butylene) is obtained.

TABLE 1

In the following examples and comparative examples of the present invention,

the yield of <140 ℃ naphtha was defined as: the weight percentage of naphtha fraction (<140 ℃) cut out of the whole fraction product by the fractionating tower to the raw material;

the yield of light catalytic cracking feedstock is defined as: the weight percentage of the light catalytic cracking raw material (140-350 ℃) cut out from the full fraction product by a fractionating tower to the raw material;

the heavy catalytic cracking feedstock yield is defined as: the weight percentage of heavy catalytic cracking raw material (>350 ℃) and raw material cut out from the whole fraction product by a fractionating tower.

The hydrogenation protective agent, the hydrogenation demetallization agent, the hydrofining catalyst and the hydrocracking catalyst which are adopted by the invention and the post-hydrofining catalyst are all produced by China petrochemical catalyst division.

Comparative example 1

Mixing the raw material E with hydrogen, sequentially passing through a pretreatment reaction zone, a hydrofining reaction zone and a hydrocracking reaction zone, sequentially contacting with a hydrogenation protective agent, a hydrodemetallization agent, a hydrofining catalyst, a hydrocracking catalyst and a post-hydrofining catalyst for reaction, and controlling the mass fraction of aromatic hydrocarbon in the fraction of more than 350 ℃ in the hydrofining product oil to be 18%; the conversion depth of the hydrocracking reaction zone is controlled to 50% of the conversion rate of the distillate with the temperature of more than 350 ℃. And separating the reaction effluent in the hydrocracking reaction zone to obtain naphtha fraction at the temperature of less than 140 ℃, light catalytic cracking raw material fraction at the temperature of 140-350 ℃ and heavy catalytic cracking raw material fraction at the temperature of more than 350 ℃. The experimental process condition parameters and product yield and property data are shown in table 3.

As can be seen from the data in Table 3, the light catalytic cracking raw material obtained from the raw material E under the experimental process conditions has a hydrogen mass fraction of 14.18% and a UOP K value of 11.2; the obtained heavy catalytic cracking raw material has the hydrogen mass fraction of 13.48 percent and the UOP K value of 11.9, and the data show that the light and heavy catalytic cracking raw materials obtained from the raw material E can not be used as high-quality catalytic cracking raw materials.

Example 1, example 2 and example 3

The raw materials B, C and D adopted in examples 1, 2 and 3 are respectively mixed with hydrogen, and then sequentially pass through a pretreatment reaction zone, a hydrofining reaction zone and a hydrocracking reaction zone, and sequentially contact with a hydrogenation protective agent, a hydrodemetallization agent, a hydrofining catalyst, a hydrocracking catalyst and a post-hydrofining catalyst to react, the mass fractions of aromatic hydrocarbons of fractions at 350 ℃ in the hydrofining product oil are controlled to be 8%, 10% and 13%, the conversion depth of the hydrocracking reaction zone is controlled to be 10%, 36% and 43%, the reaction effluent of the hydrocracking reaction zone is separated to obtain naphtha fractions at 140 ℃, light catalytic cracking raw material fractions at 140-350 ℃ and heavy catalytic cracking raw material fractions at 350 ℃. The experimental process condition parameters and product yield and property data are shown in table 3.

From the data in table 3, it can be seen that the feeds B, C and D yield light catalytic cracking feeds with hydrogen mass fractions of 14.36%, 14.28% and 14.25%, respectively, and UOP K values of 12.4, 12.3 and 12.1, respectively, under the experimental process conditions; the obtained heavy catalytic cracking raw materials respectively have hydrogen mass fractions of 14.13%, 14.11% and 13.95%, and UOP K values of 12.8, 12.5 and 12.5, and the data show that the light and heavy catalytic cracking raw materials can be used as high-quality catalytic cracking raw materials.

Comparative example 2

The raw material D is mixed with hydrogen and then sequentially passes through a pretreatment reaction zone, a hydrofining reaction zone and a hydrocracking reaction zone, and sequentially contacts with a hydrogenation protective agent, a hydrodemetallization agent, a hydrofining catalyst, a hydrocracking catalyst and a post-hydrofining catalyst to react, the mass fraction of aromatic hydrocarbons in the distillate at 350 ℃ in the hydrofining produced oil is controlled to be 23%, the conversion depth of the distillate at 350 ℃ in the hydrocracking reaction zone is controlled to be 40%, and the reaction effluent in the hydrocracking reaction zone is separated to obtain naphtha fraction at 140 ℃, light catalytic cracking raw material fraction at 140-350 ℃ and heavy catalytic cracking raw material fraction at 350 ℃. The experimental process condition parameters and product yield and property data are shown in table 4.

As can be seen from the data in Table 4, the light catalytic cracking raw material obtained from the raw material D under the experimental process conditions had a hydrogen mass fraction of 13.93% and a UOP K value of 11.5; the obtained heavy catalytic cracking raw material has the hydrogen mass fraction of 13.62 percent and the UOP K value of 11.8, and the data show that the light and heavy catalytic cracking raw materials obtained from the raw material D under the process condition can not be used as high-quality catalytic cracking raw materials.

Example 4

The raw material D is mixed with hydrogen and then sequentially passes through a pretreatment reaction zone, a hydrofining reaction zone and a hydrocracking reaction zone, and sequentially contacts with a hydrogenation protective agent, a hydrodemetallization agent, a hydrofining catalyst, a hydrocracking catalyst and a post-hydrofining catalyst to react, the mass fraction of fraction aromatic hydrocarbon at 350 ℃ in the hydrofining produced oil is controlled to be 16%, the conversion depth of the hydrocracking reaction zone is controlled to be 40% of fraction conversion at 350 ℃, reaction effluent of the hydrocracking reaction zone is separated to obtain naphtha fraction at 140 ℃, light catalytic cracking raw material fraction at 140-350 ℃ and heavy catalytic cracking raw material fraction at 350 ℃. The experimental process condition parameters and product yield and property data are shown in table 4.

As can be seen from the data in Table 4, the light catalytic cracking raw material obtained from the raw material D under the experimental process conditions has a hydrogen mass fraction of 14.20% and a UOP K value of 12.0; the obtained heavy catalytic cracking raw material has the mass fraction of hydrogen of 13.92 percent and the UOP K value of 12.3, and the data show that the light and heavy catalytic cracking raw materials can be used as high-quality catalytic cracking raw materials by adopting the method provided by the invention.

Comparative example 3

The raw material B is mixed with hydrogen and then sequentially passes through a pretreatment reaction zone, a hydrofining reaction zone and a hydrocracking reaction zone, and sequentially contacts with a hydrogenation protective agent, a hydrodemetallization agent, a hydrofining catalyst, a hydrocracking catalyst and a post-hydrofining catalyst to react, the mass fraction of fraction aromatic hydrocarbon of the hydrofined product oil at 350 ℃ is controlled to be 15%, the conversion depth of the hydrocracking reaction zone is controlled to be more than 350 ℃, the conversion rate of the fraction is controlled to be 7%, and the reaction effluent of the hydrocracking reaction zone is separated to obtain a naphtha fraction at 140 ℃, a light catalytic cracking raw material fraction at 140-350 ℃ and a heavy catalytic cracking raw material fraction at 350 ℃. The experimental process condition parameters and product yield and property data are shown in table 5.

As can be seen from the data in Table 5, the light catalytic cracking raw material obtained from the raw material B under the experimental process conditions had a hydrogen mass fraction of 14.12% and a UOP K value of 11.8; the obtained heavy catalytic cracking raw material has a hydrogen mass fraction of 13.97% and a UOP K value of 12.1, and the above data show that the obtained light catalytic cracking raw material cannot be used as a high-quality catalytic cracking raw material although the raw material B with better properties is used.

Example 5

The raw material B is mixed with hydrogen and then sequentially passes through a pretreatment reaction zone, a hydrofining reaction zone and a hydrocracking reaction zone, and sequentially contacts with a hydrogenation protective agent, a hydrodemetallization agent, a hydrofining catalyst, a hydrocracking catalyst and a post-hydrofining catalyst to react, the mass fraction of fraction aromatic hydrocarbon of the hydrofined product oil at 350 ℃ is controlled to be 10%, the conversion depth of the hydrocracking reaction zone is controlled to be 10% and the conversion rate of the fraction at 350 ℃, and the reaction effluent of the hydrocracking reaction zone is separated to obtain naphtha fraction at 140 ℃, light catalytic cracking raw material fraction at 140-350 ℃ and heavy catalytic cracking raw material fraction at 350 ℃. The experimental process condition parameters and product yield and property data are shown in table 5.

As can be seen from the data in Table 5, the light catalytic cracking raw material obtained from the raw material B under the experimental process conditions has a hydrogen mass fraction of 14.26% and a UOP K value of 12.2; the obtained heavy catalytic cracking raw material has the mass fraction of hydrogen of 14.03 percent and the UOP K value of 12.5, and the data show that the light and heavy catalytic cracking raw materials can be used as high-quality catalytic cracking raw materials by adopting the method provided by the invention.

TABLE 2 crude feed Properties after desalting

TABLE 3

TABLE 4

TABLE 5

Claims

1. A method for producing chemical raw materials by crude oil hydrocracking, the crude oil raw materials after dehydration and desalination are heated, and then sequentially pass through a pretreatment reaction zone, a hydrofining reaction zone and a hydrocracking reaction zone in the presence of hydrogen, the obtained reaction effluent enters a fractionating tower after gas-liquid separation, and is fractionated to obtain liquefied gas, naphtha fraction, light catalytic cracking raw materials and heavy catalytic cracking raw materials, wherein:

2. The process of claim 1 wherein the crude feed has an API value of not less than 27 and a nitrogen content of not more than 2500 μ g/g.

3. The method as claimed in claim 2, characterized in that the raw crude oil has Fe content no more than 40 μ g/g, Ca content no more than 40 μ g/g, Ni content no more than 20 μ g/g, V content no more than 20 μ g/g, carbon residue quality fraction no more than 15%, and asphaltene content no more than 5000 μ g/g.

4. The process of claim 1, wherein the reaction conditions in the pretreatment reaction zone are: the reaction pressure is 6.0MPa to 20.0MPa, the reaction temperature is 260 ℃ to 420 ℃, and the liquid hourly space velocity is 0.5h^-1～15h^-1The volume ratio of hydrogen to oil is 300-2000.

5. The process of claim 1, wherein the hydrofinishing reaction zone reaction conditions are: the reaction pressure is 6.0MPa to 20.0MPa, the reaction temperature is 280 ℃ to 400 ℃, and the liquid hourly volume space velocity is 0.5h^-1～6h^-1The volume ratio of hydrogen to oil is 300-2000;

the conversion depth of the hydrofining reaction zone is controlled to control the mass fraction of aromatic hydrocarbon in the distillate with the temperature of more than 350 ℃ in the hydrofining generated oil to be not more than 16%.

6. The process of claim 1, wherein the hydrocracking reaction zone reaction conditions are: the reaction pressure is 6.0MPa to 20.0MPa, the reaction temperature is 290 ℃ to 420 ℃, and the liquid hourly space velocity is 0.3h^-1～5h^-1The volume ratio of hydrogen to oil is 300-2000.

7. The process of claim 1, wherein the hydrogenation protective agent comprises a carrier and an active metal component, wherein the carrier is alumina, the active metal component is selected from at least one group VIII metal and at least one group VIB metal, the group VIII metal is selected from nickel and/or cobalt, the group VIB metal is selected from molybdenum and/or tungsten, and the group VIII metal content is 0.3 wt% to 5 wt% and the group VIB metal content is 1 wt% to 10 wt% calculated by oxides based on the total weight of the hydrogenation protective agent.

8. The process of claim 1 or 7, wherein at least two or more kinds of the hydrogenation protecting agents are charged in the pretreatment reaction zone, and the particle size of the hydrogenation protecting agent gradually decreases and the mass fraction of the active metal component gradually increases in the direction of the flow of the reactants.

9. The process of claim 1, wherein the hydrodemetallization agent comprises a carrier and an active metal component, wherein the carrier is alumina, the active metal component is selected from at least one group VIII metal and at least one group VIB metal, the group VIII metal is selected from nickel and/or cobalt, the group VIB metal is selected from molybdenum and/or tungsten, and the group VIII metal content is 1-5 wt% and the group VIB metal content is 1-15 wt% calculated by oxides based on the total weight of the hydrodemetallization agent.

10. The process of claim 1 or 9, wherein the pretreatment reaction zone is charged with at least two or more hydrodemetallization agents, the hydrodemetallization agents having progressively smaller particle sizes and progressively increasing mass fractions of the reactive metal components in the direction of reactant flow.

11. The process of claim 1, wherein the hydrofinishing catalyst is at least one catalyst selected from group VIB metals, or at least one catalyst selected from group VIII metals, or a combination thereof, supported on an alumina or/and alumina-silica support.

12. The process of claim 11 wherein the group VIII metal is selected from nickel and/or cobalt and the group VIB metal is selected from molybdenum and/or tungsten, the nickel and/or cobalt being present in an amount of from 1 wt.% to 15 wt.% and the molybdenum and/or tungsten being present in an amount of from 5 wt.% to 40 wt.% on an oxide basis, based on the total weight of the hydrofinishing catalyst.

13. The process according to claim 1, wherein the hydrocracking catalyst comprises a carrier composed of a refractory inorganic oxide and a Y-type molecular sieve, and an active metal component supported on the carrier; the heat-resistant inorganic oxide is selected from one or more of silicon oxide, aluminum oxide and amorphous aluminum silicate; the active metal component is selected from at least two metal components of VIB group metals and VIII group metals; based on the whole hydrocracking catalyst, calculated by oxides, 15-35 wt% of VIB group metal, 2-8 wt% of VIII group metal, 3-35 wt% of Y-type molecular sieve and the balance of heat-resistant inorganic oxides.

14. The process of claim 1, wherein the post-hydrofinishing catalyst is loaded at the lower portion of the hydrocracking reaction zone, and the loading ratio of the hydrocracking catalyst to the post-hydrofinishing catalyst is 8: 1-15: 1.

15. the method according to claim 1, wherein the cut point of the naphtha fraction and the light catalytic cracking raw material is 130 to 160 ℃; the cutting point of the light catalytic cracking raw material and the heavy catalytic cracking raw material is 330-380 ℃.

16. The process according to claim 1 or 15, wherein the light catalytic cracking raw material has a hydrogen mass fraction of not less than 13.5% and a UOP K value of not less than 12;

the mass fraction of hydrogen in the raw material for heavy catalytic cracking is not less than 13.5%.