CN113930255B

CN113930255B - Hydrogenation method for producing chemical raw materials from crude oil

Info

Publication number: CN113930255B
Application number: CN202010609280.1A
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: 2023-06-09
Anticipated expiration: 2040-06-29
Also published as: CN113930255A

Abstract

A hydrogenation method for producing chemical raw materials from crude oil sequentially passes through a first pretreatment reaction zone, a second pretreatment reaction zone, a hydrofining reaction zone and a hydrocracking reaction zone, and the obtained reaction effluent is subjected to gas-liquid separation and then enters a fractionating tower to be fractionated to obtain liquefied gas, naphtha fraction, light catalytic cracking raw materials and heavy catalytic cracking raw materials. The method can realize direct production of high-quality chemical raw materials from crude oil.

Description

Hydrogenation method for producing chemical raw materials from crude oil

Technical Field

The 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 demands of the automotive fuel gasoline and diesel oil in China are slowed down year by year, the market demands of the automotive fuel oil are further reduced in the future under the influence of the development of new energy automobiles using hydrogen energy and electric energy, and meanwhile, the social consumption upgrading is brought to the development of national economy, so that the consumption demands of olefins and aromatic hydrocarbons which can be used as synthetic monomers of various materials are continuously increased.

When the current refineries are classified into fuel oil type, fuel oil-chemical type and full chemical type refineries according to the ratio of fuel oil products and chemical products, and the transition from the fuel oil type refineries to the full chemical type refineries is made, the ratio of chemical products in the structure of the refinery products is gradually increased. In order to meet the market demands of future fuel oil and chemical products, a traditional fuel oil refinery with a certain proportion is transformed into the chemical refinery, however, under the crude oil processing flow of the existing fuel oil refinery, crude oil is generally cut and fractionated into a plurality of narrow fractions and then is processed and produced into fuel oil respectively, and the problem that the proportion of the crude oil converted into chemical raw materials is insufficient is brought, so that the yield of chemical products in a product structure is lower; on the other hand, in the chemical transformation process of the device 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 method for hydrocracking heavy crude oil, in which heavy crude oil with API degree less than 20 is sequentially subjected to hydrogenation protective agent, hydrodemetallization agent, hydrodesulphurization agent I, hydrocracking agent and hydrodesulphurization agent II in the presence of hydrogen, and then the hydrogenated crude oil with increased API degree and reduced viscosity is obtained through separation, however, by adopting the method of the invention, hydrogenated crude oil with reduced mass fractions of impurities such as metal, sulfur, nitrogen and the like can be obtained, but the requirement of qualified chemical raw materials with production property cannot be met.

CN105358661a and CN109593556a disclose a process and a plant for converting crude oil into petrochemicals with improved propylene yields. The method comprises the steps of firstly, distilling crude oil to produce gas, kerosene and/or gas oil and residual oil, and on the one hand, upgrading the residual oil to produce LPG and modified effluent; on the other hand, the upgraded effluent undergoes at least 50% aromatic ring opening with kerosene and gas oil to produce petrochemicals.

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

CN106103664a discloses an integrated hydrocracking process. The method comprises the steps of carrying out hydrotreatment on crude oil and raw materials from coking in a first hydrogenation reaction zone to obtain a stream which is separated into LPG and a liquid-phase stream, enabling the liquid-phase stream to enter a second hydrocracking zone for reaction to generate a BTXE stream, and carrying out thermal cracking on the residual liquid stream to generate a coking liquid product and petroleum coke.

Disclosure of Invention

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

The hydrogenation method for producing chemical raw materials from crude oil provided by the invention comprises the following steps: crude oil raw materials sequentially pass through a first pretreatment reaction zone, a second pretreatment reaction zone, a hydrofining reaction zone and a hydrocracking reaction zone, and the obtained reaction effluent is subjected to gas-liquid separation and then enters a fractionating tower to be fractionated to obtain liquefied gas, naphtha fraction, light catalytic cracking raw materials and heavy catalytic cracking raw materials, wherein:

(1) The first pretreatment reaction zone is graded filled with a first hydrogenation protective agent and a first hydrodemetallization agent, and the first pretreatment reaction zone controls the removal rate of metallic iron and calcium to be no less than 70%;

the second pretreatment reaction zone is graded filled with a second hydrogenation protective agent and a second hydrodemetallization agent, and the total demetallization rate of the first pretreatment reaction zone and the second pretreatment reaction zone is controlled to be less than or equal to 90% and the total deasphalting rate is controlled to be less than or equal to 90%;

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

(3) The hydrocracking reaction zone is filled with a hydrocracking catalyst, and the conversion depth of the hydrocracking reaction zone is controlled to be more than 350 ℃ and the conversion rate of the fraction is controlled 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 feedstock has an API grade of no less than 27 and a nitrogen content of no more than 2500 μg/g. Further preferably, the crude oil raw material contains Fe not more than 40 mug/g, ca not more than 40 mug/g, ni not more than 20 mug/g, V not more than 20 mug/g, carbon residue mass fraction not more than 15%, asphaltene not more than 5000 mug/g.

In a preferred embodiment of the present invention, after the crude oil raw material is dehydrated and desalted, the crude oil raw material is sequentially contacted with a first hydrogenation protecting agent and a first hydrogenation demetallizing agent in a first pretreatment reaction zone to mainly carry out hydrodeiron and hydrodecalcium reactions. The reaction effluent of the first pretreatment reaction zone enters the second pretreatment reaction zone without separation, and contacts with a second hydrogenation protective agent and a second hydrogenation demetallization agent to carry out hydrogenation demetallization and hydrogenation asphaltene reaction. Alternatively, in another preferred embodiment of the present invention, the reaction effluent from the first pretreatment reaction zone is subjected to gas-liquid separation, the separated hydrogen-rich gas is recycled, and the separated liquid stream is fed to the second pretreatment reaction zone for further reaction.

In a preferred aspect of the invention, the reaction pressure in the first pretreatment reaction zone is less than the reaction pressure in the second pretreatment reaction zone, and the reaction pressure in the first pretreatment reaction zone is no more than 8MPa.

In preferred cases, the reaction conditions of the first pretreatment reaction zone: the reaction pressure is 2.0 MPa-7.9 MPa, the reaction temperature is 260-420 ℃, and the liquid hourly space velocity is 0.5h ^-1 ～15h ^-1 The volume ratio of hydrogen to oil is 50-600;

reaction conditions in the second pretreatment reaction zone: the reaction pressure is 8.0 MPa-20.0 MPa, the reaction temperature is 260-420 ℃, and the liquid hourly space velocity is 0.5h ^-1 ～15h ^-1 The volume ratio of hydrogen to oil is 300-2000.

In a preferred case, according to the direction of the reactant flow, the first pretreatment reaction zone is sequentially filled with a first hydrogenation protecting agent and a first hydrodemetallization agent, wherein the filling volume ratio of the first hydrogenation protecting agent to the first hydrodemetallization agent is 1: 3-2: 1, a step of;

the first 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 VIII group metal and at least one VIB group metal, the VIII group metal is selected from nickel and/or cobalt, the VIB group metal is selected from molybdenum and/or tungsten, the content of the VIII group metal is 0.3-5 wt% based on the total weight of the first hydrogenation protective agent, and the content of the VIB group metal is 1-10 wt% based on oxide;

the first 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 VIII group metal and at least one VIB group metal, the VIII group metal is selected from nickel and/or cobalt, the VIB group metal is selected from molybdenum and/or tungsten, the total weight of the first hydrodemetallization agent is taken as a reference, the content of the VIII group metal is 1-5 wt% based on oxides, and the content of the VIB group metal is 1-15 wt%.

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

In a preferred case, according to the direction of the reactant flow, the second pretreatment reaction zone is sequentially filled with a second hydrogenation protecting agent and a second hydrodemetallization agent, wherein the filling volume ratio of the second hydrogenation protecting agent to the second hydrodemetallization agent is 1: 6-1: 1, a step of;

the second 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 VIII group metal and at least one VIB group metal, the VIII group metal is selected from nickel and/or cobalt, the VIB group metal is selected from molybdenum and/or tungsten, the content of the VIII group metal is 0.3-5 wt% based on the total weight of the second hydrogenation protective agent, and the content of the VIB group metal is 1-10 wt% based on oxide;

the second 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 VIII group metal and at least one VIB group metal, the VIII group metal is selected from nickel and/or cobalt, the VIB group metal is selected from molybdenum and/or tungsten, the content of the VIII group metal is 1-5 wt% based on the total weight of the second hydrodemetallization agent, and the content of the VIB group metal is 1-15 wt% based on oxide.

In a preferred embodiment of the present invention, at least two or more second hydrogenation protecting agents are filled in the second pretreatment reaction zone, the particle size of the second hydrogenation protecting agents gradually becomes smaller along the direction of the reactant flow, and the mass fraction of the active metal component gradually increases;

at least two or more second hydrodemetallization agents are filled in the second pretreatment reaction zone, the particle size of the second hydrodemetallization agents gradually becomes smaller along the direction of the reactant flow, and the mass fraction of the active metal components gradually increases.

In a preferred case, the hydrogen source of the first pretreatment reaction zone is sulfur-containing hydrogen-rich gas, and the hydrogen source is selected from one or more of circulating hydrogen before desulfurization, dry gas before desulfurization and low-pressure gas before desulfurization, and the sulfide concentration of the sulfur-containing hydrogen-rich gas is 5000 mu L/L to 50000 mu L/L.

In a preferred embodiment of the invention, more than two shift reactors are provided in the first pretreatment reaction zone, with the crude oil feed entering at least one of the reactors. When the pressure drop of the on-line reactor into which the crude oil raw material enters is increased to a limiting value, the crude oil raw material can be selectively switched into another reactor, the on-line reactor with high pressure drop is cut out, and the first hydrogenation protecting agent and the first hydrogenation demetallizing agent are replaced.

In a preferred embodiment of the invention, a shift reactor is not arranged in the first pretreatment reaction zone, and when the pressure drop of the first pretreatment reaction zone reaches more than 80% of the design value of the pressure drop, the crude oil raw material does not enter the first pretreatment reaction zone any more and directly enters the second pretreatment reaction zone for reaction. The first hydrogenation protective agent and the first hydrodemetallization agent in the first pretreatment reaction zone can be replaced; or the catalyst is replaced together after the whole crude oil hydrogenation device is stopped without replacement.

The invention sets the low-pressure first pretreatment reaction zone, removes metal impurities such as iron, calcium and the like which have great influence on the service life of the hydrogenation catalyst, and effectively prolongs the operation period of the whole crude oil hydrogenation device by flexibly switching the implementation mode of treatment.

In the invention, the reaction effluent of the second pretreatment reaction zone directly enters the hydrofining reaction zone without separation, contacts with a hydrofining catalyst, and carries out the reactions of hydrodesulfurization, hydrodenitrogenation, partial saturation of aromatic hydrocarbon and the like. In preferred cases, the hydrofinishing reaction zone reaction conditions: the reaction pressure is 8.0 MPa-20.0 MPa, the reaction temperature is 280-400 ℃, and the liquid hourly space velocity is 0.5h ^-1 ～6h ^-1 The volume ratio of hydrogen to oil is 300-2000.

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

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

In the present invention, a gas-liquid separation device may be provided or may be omitted between the hydrofining reaction zone and the hydrocracking reaction zone. When the gas-liquid separation equipment is not 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 hydrofined oil. Preferably, a gas-liquid separation device is arranged, and the hydrogen-rich gas and the hydrofining generated oil are obtained after the gas-liquid separation of the hydrofining reaction effluent. The hydrofining generated oil enters a hydrocracking reaction zone to contact with a hydrocracking catalyst for a hydrocracking reaction.

In preferred cases, the hydrocracking reaction zone reaction conditions: the reaction pressure is 8.0 MPa-20.0 MPa, the reaction temperature is 290-420 ℃, and the liquid hourly space velocity is 0.3h ^-1 ～5h ^-1 The volume ratio of hydrogen to oil is 300-2000;

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

In the present invention, the conversion rate of the fraction at >350 ℃ is as follows: 100 (fraction mass fraction of >350 ℃ in feedstock-fraction mass fraction of >350 ℃ in hydrocracked oils)/fraction mass fraction of >350 ℃ in feedstock

In a preferred case, the hydrocracking catalyst comprises a carrier and an active metal component supported on the carrier, the carrier consisting of a refractory 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 metal and VIII group metal; the hydrocracking catalyst is 15-35 wt% of VIB metal, 2-8 wt% of VIII metal, 3-35 wt% of Y-type molecular sieve and the balance of heat-resistant inorganic oxide.

In a preferred embodiment of the present invention, the hydrocracking reaction zone is filled with the post-hydrofining catalyst at a lower portion thereof, and the filling ratio of the hydrocracking catalyst to the post-hydrofining catalyst is 8:1 to 15:1. according to the material flow direction, the hydrofining generated oil sequentially passes through a hydrocracking catalyst and a post hydrofining catalyst.

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

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

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

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

The catalytic cracking process refers to a process of producing low-carbon olefins such as ethylene, propylene, butylene and the like by high-temperature cracking of petroleum hydrocarbon in the presence of a catalyst and simultaneously producing light aromatic hydrocarbon, and can be specifically one or more of a catalytic cracking process (DCC process), a catalytic pyrolysis process (CPP process), a process of preparing ethylene by directly cracking 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 invention are high-quality raw materials in the catalytic cracking process, and the obtained low-carbon olefin has high yield and high product income. Specifically, the weight fraction of hydrogen in the light catalytic cracking raw material obtained by the invention is not less than 13.5 percent, and the UOP K value of the light catalytic cracking raw material is not less than 12. The mass fraction of hydrogen in the heavy catalytic cracking raw material obtained by the invention is less than or equal to 13.5%.

The inventors of the present invention have found through intensive 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 catalytic cracking raw material is controlled to be less than or equal to 13.5%, good catalytic cracking product benefits can be obtained. In addition, the economy of the catalytic cracking device is in positive correlation with the UOPK value of the raw material, the UOP value of the raw material is generally larger than 11.9, the catalytic cracking (DCC) device can be guaranteed to have better economy, and the yield of ethylene, propylene and butene of the catalytic cracking device is gradually increased along with the increase of the UOP 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 from the formula

Wherein Tv is the volume average boiling point of the raw material, d _15.6 Is the density of the raw material at 15.6 ℃.

The treatment method provided by the invention is used for producing high-quality chemical raw materials, particularly high-quality light catalytic cracking raw materials in large scale by a hydrocracking method, wherein the light catalytic cracking raw materials meet the requirements of 13.5% of hydrogen mass fraction and 12 of UOP K value. The heavy catalytic cracking raw material obtained by the method meets the mass fraction of hydrogen of less than 13.5 percent, and is also a high-quality catalytic cracking raw material. The high-quality catalytic cracking raw material is adopted, and the catalytic cracking device can achieve the purpose of improving the yield of the high-value products of the low-carbon olefin.

Detailed Description

The following examples further illustrate a hydrogenation process for producing upgraded materials from crude oil according to the present invention, but the present invention is not limited thereto.

Comparative example 1-1, example 1-1

The comparative examples and examples are presented to illustrate the effect of the differences in the nature of the light catalytic cracking feedstock on the product yield of the catalytic cracker.

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

The catalytic cracking catalyst is used with the commodity brand of 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 agent-oil ratio is 12, and the steam injection amount is 25 weight percent (accounting for the raw materials).

As is clear from the data in Table 1, the two light catalytic cracking raw materials with the same distillation range and different hydrogen content and UOP K value react under the same catalytic cracking process conditions, the mass fraction of hydrogen in the light catalytic cracking raw material 2 is more than 13.5%, and the UOP K value is more than 12, so that the 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 naphtha at 140 ℃ is defined as: the weight percentage of naphtha fraction (< 140 ℃) and raw materials cut by the whole fraction product through a fractionating tower;

the light catalytic cracking raw material yield is defined as follows: the whole fraction product is cut by a fractionating tower to obtain light catalytic cracking raw materials (140-350 ℃) and weight percentage of the raw materials;

the heavy catalytic cracking feedstock yield is defined as: the whole fraction product is obtained by cutting heavy catalytic cracking raw materials (> 350 ℃) through a fractionating tower and the weight percentage of the raw materials.

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

Comparative example 1

Raw material E and hydrogen are mixed and then sequentially pass through a first pretreatment reaction zone, a second pretreatment reaction zone, a hydrofining reaction zone and a hydrocracking reaction zone, and then sequentially contact and react with a first hydrogenation protecting agent, a first hydrogenation demetallizing agent, a second hydrogenation protecting agent, a second hydrogenation demetallizing agent, a hydrofining catalyst, a hydrocracking catalyst and a post-hydrofining catalyst, and the mass fraction of aromatic hydrocarbon in fraction with the temperature of more than 350 ℃ in hydrofining generated oil is controlled to be 18%; the conversion depth in the hydrocracking reaction zone was controlled to be >350 ℃ and the conversion of the fraction was 50%. The reaction effluent of the hydrocracking reaction zone is separated to obtain naphtha fraction of <140 ℃, light catalytic cracking raw material fraction of 140-350 ℃ and heavy catalytic cracking raw material fraction of >350 ℃. The process condition parameters and product yields and property data are shown in Table 3.

As can be seen from the data in table 3, feedstock E had an overall demetallization ratio of 88% for the first and second pretreatment reaction zones under the experimental process conditions; the mass fraction of the hydrogen in the obtained light catalytic cracking raw material is 13.88%, and the UOP K value is 11.1; the mass fraction of the hydrogen in the obtained heavy catalytic cracking raw material is 13.40%, and the UOP K value is 11.7. On the one hand, the above data indicate that neither the light nor heavy catalytic cracking feedstock obtained from feedstock E is a good quality catalytic cracking feedstock. On the other hand, the insufficient metal removal rate in the pretreatment reaction zone can shorten the service life of the hydrofining catalyst at the downstream, thereby affecting the operation period of the whole device.

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 first pretreatment reaction zone, a second pretreatment reaction zone, a hydrofining reaction zone and a hydrocracking reaction zone, and then are sequentially contacted with a first hydrogenation protecting agent, a first hydrodemetallation agent, a second hydrogenation protecting agent, a second hydrodemetallation agent, a hydrofining catalyst, a hydrocracking catalyst and a post-hydrofining catalyst for reaction, wherein the mass fractions of the fraction aromatic hydrocarbons with the temperature of more than 350 ℃ in the hydrofining generated oil are respectively 8%, 10% and 13%, the conversion depth of the hydrocracking reaction zone is controlled to be respectively 10%, 36% and 43%, and the reaction effluent of the hydrocracking reaction zone is separated to obtain a naphtha fraction with the temperature of less than 140 ℃, a light catalytic cracking raw material fraction with the temperature of 140-350 ℃ and a heavy catalytic cracking raw material fraction with the temperature of more than 350 ℃. The process condition parameters and product yields and property data are shown in Table 3.

As can be seen from the data in table 3, under the experimental process conditions, the raw materials B, C and D have a deironing rate and a decalcification rate of more than 70% in the first pretreatment reaction zone, and an overall demetallizing rate of more than 90% in the first and second pretreatment reaction zones, so that the obtained light catalytic cracking raw materials have hydrogen mass fractions of 14.05%, 14.03% and 13.75% and UOP K values of 12.3, 12.2 and 12.0, respectively; the mass fractions of the obtained heavy catalytic cracking raw materials are 14.05%, 14.03% and 13.75%, and the UOP K values are 12.6, 12.4 and 12.4 respectively.

Comparative example 2

The raw material D and hydrogen are mixed and 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 for reaction, wherein the mass fraction of fraction aromatics with the temperature of more than 350 ℃ in hydrofining generated oil is controlled to be 23%, the conversion depth of the hydrocracking reaction zone is controlled to be 40% of fraction conversion rate with the temperature of more than 350 ℃, and the reaction effluent of the hydrocracking reaction zone is separated to obtain naphtha fraction with the temperature of less than 140 ℃, light catalytic cracking raw material fraction with the temperature of 140-350 ℃ and heavy catalytic cracking raw material fraction with the temperature of more than 350 ℃. The process condition parameters and product yields and property data are shown in Table 4.

As can be seen from the data in table 4, the demetallization rate of the pretreatment reaction zone was 95% under the experimental process conditions for feedstock D; the mass fraction of the hydrogen in the obtained light catalytic cracking raw material is 13.75%, and the UOP K value is 11.3; the mass fraction of the obtained heavy catalytic cracking raw material hydrogen is 13.52%, the UOP K value is 11.6, and the data show that the light and heavy catalytic cracking raw materials obtained from the raw material D under the process condition cannot 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 first pretreatment reaction zone, a second pretreatment reaction zone, a hydrofining reaction zone and a hydrocracking reaction zone, and then sequentially contacts with a first hydrogenation protecting agent, a first hydrogenation demetallizing agent, a second hydrogenation protecting agent, a second hydrogenation demetallizing agent, a hydrofining catalyst, a hydrocracking catalyst and a post-hydrofining catalyst for reaction, wherein the mass fraction of fraction aromatics at the temperature of 350 ℃ in the hydrofining generated oil is controlled to be 16%, the conversion depth of the hydrocracking reaction zone is controlled to be 40%, and the reaction effluent of the hydrocracking reaction zone is separated to obtain naphtha fraction at the temperature of 140 ℃, light catalytic cracking raw material fraction at the temperature of 140-350 ℃ and heavy catalytic cracking raw material fraction at the temperature of 350 ℃. The process condition parameters and product yields and property data are shown in Table 4.

As can be seen from the data in table 4, under the experimental process conditions, the iron removal rate and the decalcification rate of the first pretreatment reaction zone are 82% and 75%, the overall demetallization rate of the first and second pretreatment reaction zones is 97%, the mass fraction of the obtained light catalytic cracking raw material hydrogen is 14.18%, and the UOP K value is 12.0; the mass fraction of the obtained heavy catalytic cracking raw material hydrogen is 13.92%, and the UOP K value is 12.3, and the data show that the light and heavy catalytic cracking raw materials obtained by the method provided by the invention can be used as high-quality catalytic cracking raw materials.

Under the condition that the volume space velocities of the two pretreatment unit liquids are consistent, the first pretreatment reaction zone can remove iron and calcium in the raw oil under low pressure, so that on one hand, the operation cost is effectively saved, and on the other hand, the metal removal burden of the high-pressure pretreatment reaction zone is lightened, and the effect of improving the metal removal rate of the pretreatment reaction zone in an effective operation period is achieved.

Comparative example 3

The raw material B is mixed with hydrogen and then sequentially passes through a first pretreatment reaction zone, a second pretreatment reaction zone, a hydrofining reaction zone and a hydrocracking reaction zone, and then sequentially contacts with a first hydrogenation protecting agent, a first hydrogenation demetallizing agent, a second hydrogenation protecting agent, a second hydrogenation demetallizing agent, a hydrofining catalyst, a hydrocracking catalyst and a post-hydrofining catalyst for reaction, the mass fraction of distillate aromatic hydrocarbon with the temperature of the hydrofining generated oil being more than 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 distillate is controlled to be 7%, and the reaction effluent of the hydrocracking reaction zone is separated to obtain naphtha fraction with the temperature of <140 ℃, light catalytic cracking raw material fraction with the temperature of 140-350 ℃ and heavy catalytic cracking raw material fraction with the temperature of more than 350 ℃. The process condition parameters and product yields and property data are shown in Table 5.

As can be seen from the data in table 5, the mass fraction of the light catalytic cracking raw material hydrogen obtained from the raw material B under the experimental process conditions is 13.95%, and the UOP K value is 11.6; the mass fraction of hydrogen in the obtained heavy catalytic cracking raw material was 13.67%, and the UOP K value was 12.0, and the above data indicate that the obtained light catalytic cracking raw material could not be used as a high-quality catalytic cracking raw material, although the raw material B having a good property was used.

Example 5

The raw material B is mixed with hydrogen and then sequentially passes through a first pretreatment reaction zone, a second pretreatment reaction zone, a hydrofining reaction zone and a hydrocracking reaction zone, and then sequentially contacts with a first hydrogenation protecting agent, a first hydrogenation demetallizing agent, a second hydrogenation protecting agent, a second hydrogenation demetallizing agent, a hydrofining catalyst, a hydrocracking catalyst and a post-hydrofining catalyst for reaction, the mass fraction of distillate aromatic hydrocarbon with the temperature of the hydrofining generated oil being more than 350 ℃ is controlled to be 10%, the conversion depth of the hydrocracking reaction zone is controlled to be more than 350 ℃, the conversion rate of the distillate is controlled to be 10%, and reaction effluent of the hydrocracking reaction zone is separated to obtain naphtha fraction with the temperature of <140 ℃, light catalytic cracking raw material fraction with the temperature of 140-350 ℃ and heavy catalytic cracking raw material fraction with the temperature of more than 350 ℃. The process condition parameters and product yields and property data are shown in Table 5.

As can be seen from the data in table 5, the mass fraction of the light catalytic cracking raw material hydrogen obtained from the raw material B under the experimental process conditions is 14.21%, and the UOP K value is 12.13; the mass fraction of the obtained heavy catalytic cracking raw material hydrogen is 14.0%, the UOP K value is 12.21, and the data show that the raw material B adopts the method provided by the invention, and the obtained light and heavy catalytic cracking raw materials can be used as high-quality catalytic cracking raw materials.

TABLE 2 crude oil feedstock Properties after desalting

Project	Crude oil B	Crude oil C	Crude oil D	Crude oil E
					API degree	31.65	28.3	27.6	24.94
Density (20 ℃ C.)/(g/cm) ³ )	0.8656	0.8820	0.8863	0.9005
					Sulfur mass fraction/%	0.32	0.835	0.915	0.80
Nitrogen content/(μg/g)	282	840	1589	4100
					Carbon residue value/wt%	<0.3	<0.3	3.23	6.4
Asphaltene/(μg/g)	<1000	<1000	1230	8500
					Metal mass fraction/(μg/g)
Fe	6.4	15.1	15.1	13.0
					Ni	1.2	6.2	2.7	26.0
V	1.5	6.2	<0.1	1.6
					Ca	2.5	26.4	8.0	8.9
>Fraction at 350 ℃ in weight percent	26.3	67.16	69.01	75

TABLE 3 Table 3

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TABLE 4 Table 4

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TABLE 5

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Claims

1. A hydrogenation method for producing chemical raw materials from crude oil sequentially passes through a first pretreatment reaction zone, a second pretreatment reaction zone, a hydrofining reaction zone and a hydrocracking reaction zone, and the obtained reaction effluent is subjected to gas-liquid separation and then enters a fractionating tower to be fractionated to obtain liquefied gas, naphtha fraction, light catalytic cracking raw materials and heavy catalytic cracking raw materials, wherein:

the second pretreatment reaction zone is graded filled with a second hydrogenation protective agent and a second hydrodemetallization agent, and the total demetallization rate of the first pretreatment reaction zone and the second pretreatment reaction zone is controlled to be less than or equal to 90% and the total deasphalting rate is controlled to be less than or equal to 90%; the reaction pressure of the first pretreatment reaction zone is smaller than that of the second pretreatment reaction zone, the reaction pressure of the first pretreatment reaction zone is 2.0 MPa-7.9 MPa, the volume ratio of hydrogen to oil is 50-600, the reaction pressure of the second pretreatment reaction zone is 8.0 MPa-20.0 MPa, the volume ratio of hydrogen to oil is 300-2000, the hydrogen source of the first pretreatment reaction zone is sulfur-containing hydrogen-rich gas, and the sulfur concentration of the sulfur-containing hydrogen-rich gas is 5000 mu L/L-50000 mu L/L;

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

the API degree of the crude oil raw material is not less than 27, and the nitrogen content is not more than 2500 mu g/g;

the cutting point of the naphtha fraction and the light catalytic cracking raw material is 130-160 ℃, and the cutting point of the light catalytic cracking raw material and the heavy catalytic cracking raw material is 330-380 ℃; the weight fraction of hydrogen in the light catalytic cracking raw material is not less than 13.5 percent, and the UOP K value of the light catalytic cracking raw material is not less than 12; the mass fraction of hydrogen in the heavy catalytic cracking raw material is not less than 13.5 percent,

the UOP K value is calculated by a formula

2. The method of claim 1, wherein the crude oil feed contains no more than 40 μg/g of Fe, no more than 40 μg/g of Ca, no more than 20 μg/g of Ni, no more than 20 μg/g of V, no more than 15% of carbon residue mass fraction, and no more than 5000 μg/g of asphaltene.

3. According to claim 1Process characterized in that the reaction conditions of the first pretreatment reaction zone: the reaction temperature is 260-420 ℃, and the liquid hourly space velocity is 0.5h ^-1 ～15h ^-1 ；

Reaction conditions in the second pretreatment reaction zone: the reaction temperature is 260-420 ℃, and the liquid hourly space velocity is 0.5h ^-1 ～15h ^-1 。

4. The method of claim 1, wherein the first pretreatment reaction zone is charged with the first hydroprotectant and the first hydrodemetallization agent in sequence in the direction of the reactant flow, the first hydroprotectant and the first hydrodemetallization agent being charged in a volumetric ratio of 1: 3-2: 1, a step of;

5. The process of claim 4 wherein the first pretreatment reaction zone is charged with at least two first hydrodemetallization agents having progressively smaller particle sizes and progressively higher mass fractions of the active metal component along the reactant flow direction.

6. The process of claim 1 wherein the second pretreatment reaction zone is charged with a second hydroprotectant and a second hydrodemetallization agent in sequence, in terms of reactant flow direction, the second hydroprotectant and second hydrodemetallization agent being charged in a volumetric ratio of 1: 6-1: 1, a step of;

7. The process of claim 6 wherein at least two second hydroprotectants are charged into the second pretreatment reaction zone, the second hydroprotectants having progressively smaller particle sizes and progressively higher mass fractions of the active metal component along the reactant flow direction;

at least two second hydrodemetallization agents are filled in the second pretreatment reaction zone, the particle size of the second hydrodemetallization agents gradually becomes smaller along the direction of the reactant flow, and the mass fraction of the active metal components gradually increases.

8. The method of claim 1 wherein 1 or more than two rotatable reactors are provided in the first pretreatment reaction zone and the crude feed is introduced into at least one of the reactors.

9. The method according to claim 1, wherein when the pressure drop of the first pretreatment reaction zone reaches 80% of the design value of the pressure drop, the crude oil raw material does not enter the first pretreatment reaction zone any more, and directly enters the second pretreatment reaction zone, and the flow of the crude oil is switched to the first pretreatment reaction zone and the second pretreatment reaction zone after the catalyst of the cut first pretreatment reaction zone is replaced; or crude oil is cut out from the reactor of the first pretreatment reaction zone, the pressure drop of which reaches a design value, and the reactor of the first pretreatment reaction zone can be replaced, so that the flow of the raw oil is the first pretreatment reaction zone and the second pretreatment reaction zone; or directly cutting out the first pretreatment reaction zone and directly entering the second pretreatment reaction zone.

10. The process of claim 1 wherein the hydrofinishing reaction zone reaction conditions: the reaction pressure is 8.0 MPa-20.0 MPa, the reaction temperature is 280-400 ℃, and the liquid hourly space velocity is 0.5h ^-1 ～6h ^-1 The volume ratio of hydrogen to oil is 300-2000;

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

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

12. The process according to claim 11, characterized in that the group VIII metal is selected from nickel and/or cobalt and the group VIB metal is selected from molybdenum and/or tungsten in an amount of 1% to 15% by weight, calculated as oxide, and in an amount of 5% to 40% by weight, calculated as oxide, based on the total weight of the hydrofinishing catalyst.

13. The process of claim 1 wherein the hydrocracking reaction zone reaction conditions: the reaction pressure is 8.0 MPa-20.0 MPa, the reaction temperature is 290-420 ℃, and the liquid hourly space velocity is 0.3h ^-1 ～5h ^-1 The volume ratio of hydrogen to oil is 300-2000.

14. The process of claim 1 wherein the hydrocracking catalyst comprises a support and an active metal component supported on the support, the support consisting of a refractory 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 metal and VIII group metal; the hydrocracking catalyst is 15-35 wt% of VIB metal, 2-8 wt% of VIII metal, 3-35 wt% of Y-type molecular sieve and the balance of heat-resistant inorganic oxide.

15. The process of claim 1 wherein the post-hydrofinishing catalyst is packed in the lower portion of the hydrocracking reaction zone in a loading ratio of 8:1 to 15:1.