CN112029532A

CN112029532A - Method and process system for preparing gasoline and diesel oil by using coal tar and biomass oil through co-hydrogenation

Info

Publication number: CN112029532A
Application number: CN202010942595.8A
Authority: CN
Inventors: 牛梦龙; 田润芝; 范峥; 姬盼盼
Original assignee: Xian Shiyou University
Current assignee: Xian Shiyou University
Priority date: 2020-09-09
Filing date: 2020-09-09
Publication date: 2020-12-04
Anticipated expiration: 2040-09-09
Also published as: CN112029532B

Abstract

The invention discloses a method and a process system for preparing gasoline and diesel oil by mixing and hydrogenating coal tar and biomass oil, and belongs to the technical field of petrochemical energy. Firstly, catalytically hydrogenating coal tar to obtain a hydrogenation pretreated coal tar system, then mixing the hydrogenation pretreated coal tar system with biomass grease to obtain a mixed oil system, continuously carrying out catalytic hydrogenation on the mixed oil system, and then carrying out rectification treatment to obtain a gasoline and diesel oil product; the hydrogenation pretreatment is carried out on the coal tar system to form a hydrogen supply solvent through catalytic hydrogenation, and the hydrogen free radicals are utilized to carry out hydrodeoxygenation on the biomass oil. The system is provided with a plurality of reactors in stages, so that the staged catalytic hydrogenation reaction is realized, and the coal tar is subjected to hydrogenation pretreatment and then mixed with the biomass grease for catalytic hydrogenation. Compared with a single raw material hydrogenation technology, the method has the advantages of high hydrogenation speed, small coking influence and improved raw material adaptability.

Description

Method and process system for preparing gasoline and diesel oil by using coal tar and biomass oil through co-hydrogenation

Technical Field

The invention belongs to the technical field of coal chemical processing and utilization, and relates to a method and a process system for preparing gasoline and diesel oil by using coal tar and biomass grease through co-hydrogenation.

Background

With the rapid increase of economy, coal occupies a considerable proportion in the global energy consumption structure, and fuel oil is once more a product with long-term vigorous demand in the global market. However, the traditional coal chemical production mode cannot be improved well all the time, and the coal tar is used as the raw material of the fuel oil, so that the problems of low profit, aggravation of environmental pollution and the like occur due to low utilization rate. To continue to advance in modern industry, fossil energy remains an irreplaceable source of power. However, as the demand for liquid fuels in the society is increasing and the yield of coal tar is not fully satisfied, and on the other hand, as coal resources are decreasing, it is urgent to increase the conversion rate of coal tar and search clean energy to satisfy the increasing fuel oil demand.

The problems of overstock of stocks, downward profit slip and the like caused by the rough production and the excessive yield of the traditional coal chemical industry are more obvious. Meanwhile, new coal chemical technologies have been gradually developed, and have attracted attention because coal-to-liquids can effectively solve some of the problems encountered in conventional coal enterprises and improve insufficient energy distribution. Under the background, the medium temperature coal tar hydrogenation industry is widely regarded by researchers and developed. The prior medium-temperature coal tar hydrogenation process mainly comprises the following steps: pre-distillation fixed bed hydrogenation, delayed coking fixed bed hydrogenation and suspension bed hydrocracking. However, the coal tar hydrogenation raw material has high heavy component content and high viscosity, is difficult to convey in actual production, is easy to block pipelines and equipment, and is difficult to continuously produce for a long time; secondly, the coal tar has high content of unsaturated hydrocarbon, high content of heteroatom compounds, high hydrogen consumption and high difficulty in hydrogenation; in addition, the mechanical impurities in the raw materials are high and the treatment of the mechanical impurities is difficult due to the high viscosity of the raw materials; finally, the quality of the coal tar produced from different sources at different time is different, the adaptability of the coal tar hydrogenation process to the raw materials is not high, the sources of the coal tar are dispersed, the recovery work is difficult to guarantee, and the large-scale production is difficult to realize.

The biodiesel is a novel fuel prepared by taking oil wastes, waste cooking oil, animal fat and the like as raw materials and carrying out hydrogenation saturation. Due to the characteristics of environmental protection, sustainability and reproducibility, researchers have developed related researches on biodiesel in succession and achieved certain results. The production method of the biodiesel mainly comprises a direct mixing method, a micro-emulsification method, a pyrolysis method, an ester exchange method and the like. These methods all have some disadvantages, and in comparison, the ester exchange method is the method generally used at present. In recent years, new processes such as supercritical method and biocatalytic method have been applied. However, the content of oxygen-containing compounds in the biomass oil hydrogenation raw material is high, and the hydrogen consumption and difficulty of the hydrogenation reaction are high; secondly, the biomass grease source is dispersed, so that large-scale production cannot be realized; finally, the biomass grease hydrogenation process has low adaptability to raw materials, the source of the biomass grease is dispersed, the quality is difficult to control, and continuous production cannot be realized.

Therefore, the problems of low utilization rate, few sources and serious environmental pollution exist in the processing and use of the conventional coal tar, and biomass oil such as waste cooking oil, factory waste oil and the like generated in daily production and life cannot be reasonably recycled.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a method and a process system for preparing gasoline and diesel oil by using coal tar and biomass grease through hydrogenation. By the method and the matched use of the process system, the aim of finally preparing the product gasoline and diesel oil by a method for carrying out catalytic hydrogenation on the coal tar which is a byproduct in production and the biomass oil which is a pollution waste is fulfilled, the high-efficiency reutilization of the coal tar and the biomass oil is realized, and the valuable energy product gasoline and diesel oil is obtained.

In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:

the invention discloses a method for preparing gasoline and diesel oil by using coal tar and biomass oil through co-hydrogenation, which comprises the steps of mixing the coal tar and the biomass oil to obtain mixed oil, carrying out catalytic hydrogenation reaction on the mixed oil, and rectifying to obtain a gasoline and diesel oil product;

wherein, the coal tar is used as a hydrogen supply solvent to provide hydrogen free radicals in the catalytic hydrogenation process, and the hydrogen free radicals are utilized to carry out hydrodeoxygenation on the biomass oil.

Preferably, the method for preparing gasoline and diesel oil by using coal tar and biomass grease through co-hydrogenation specifically comprises the following steps:

1) mixing coal tar with biomass grease to obtain a material flow I;

2) introducing hydrogen into the material flow I, and carrying out catalytic reaction for generating straight-chain alkane by olefin hydrogenation to obtain a material flow II;

3) introducing hydrogen into the material flow II, and carrying out catalytic reaction of naphthalene hydrogenation to generate dihydronaphthalene and catalytic reaction of phenol hydrogenation deoxidation to generate cyclohexane to obtain a material flow III;

4) separating water in the material flow III to obtain a material flow IV;

5) introducing hydrogen into the material flow IV, and performing a catalytic reaction for generating tetrahydronaphthalene by hydrogenation of dihydronaphthalene and a catalytic reaction for generating tetrahydroanthracene by hydrogenation of anthracene to obtain a material flow V;

6) introducing hydrogen into the material flow V to perform tetralin hydrogenation catalytic reaction and benzene hydrogenation catalytic reaction to obtain a material flow VI;

7) and rectifying the material flow VI to obtain the gasoline and diesel oil product.

Further preferably, in the step 1), the mixing mass ratio of the coal tar and the biomass grease is (5-2) to (5-8).

Further preferably, the catalysts used in step 2) are a hydrogenation protective agent and a hydrogenation demetallization agent; wherein, the used hydrogenation protective agent comprises the following components: the carrier is gamma-Al₂O₃The hydrogenation active component is Ni 3-4% -Si 2-3%, the pore diameter distribution is 2-5 nm accounting for 20% -25%, 5-10 nm accounting for 30% -60%, more than 10nm accounting for 10% -15%, the pore volume is 0.34-0.44 cm³(ii)/g; the hydrodemetallization agent comprises the following components: the carrier is gamma-Al₂O₃The hydrogenation active component is Mo 13-15% -Ni 4-5% -SiO₂2.51 percent, the pore diameter distribution is 20 to 25 percent of 2 to 5nm, 30 to 60 percent of 5 to 10nm, 10 to 15 percent of more than 10nm and the pore volume is 0.39 to 0.49cm³/g；

The catalyst used in the step 3) is a first hydrofining agent; wherein, the components of the first hydrofining agent comprise: the carrier is gamma-Al₂O₃The hydrogenation active component is W23-24% -Ni 4-5%, the pore diameter distribution is less than 10nm and accounts for 1-5%, 10-20 nm and accounts for 10-15%, 20-50 nm and accounts for 20-30%, more than 50nm and pore volume is 0.55-0.65 cm³/g；

The catalyst used in the step 5) and the step 6) is a second hydrofining agent; wherein the second hydrofining agent comprises the following components: the carrier is gamma-Al₂O₃The hydrogenation active component is Ni 6-7% -Mo 21-22% -Ni 6-7% -P2-3% -Si 4-5%, the pore diameter distribution is less than 10nm and accounts for 1-5%, 10-20 nm and accounts for 10-15%, 20-50 nm and accounts for 20-30%, more than 50nm and pore volume is 0.55-0.65 cm³/g。

More preferably, the hydrogenation protective agent, the hydrodemetallization agent, the first hydrofining agent and the second hydrofining agent are 2:3:6: 10.

Further preferably, the catalytic reaction of the olefin hydrogenation to form the linear alkane in the step 2) comprises the following specific reaction conditions: the reaction temperature is 200-265 ℃, the reaction pressure is 8-12 MPa, and the space velocity is 0.8-1.6 h^-1The total airspeed is 0.25-0.40 h^-1The volume ratio of the hydrogen to the oil is 1200: 1-2000: 1.

Further preferably, the catalytic reaction of naphthalene hydrogenation to generate dihydronaphthalene in step 3) and the catalytic reaction of phenol hydrodeoxygenation to generate cyclohexane have specific reaction conditions: the reaction temperature is 300-340 ℃, the reaction pressure is 8-12 MPa, and the space velocity is 0.8-1.6 h^-1The total airspeed is 0.25-0.40 h^-1And the volume ratio of the hydrogen to the oil is 1200: 1-2000: 1.

Further preferably, the catalytic reaction in step 5) and step 6) comprises the following specific reaction conditions:

the reaction temperature is 330-370 ℃, the reaction pressure is 8-12 MPa, and the space velocity is 0.8-1.6 h^-1The total airspeed is 0.25-0.40 h^-1And the volume ratio of the hydrogen to the oil is 1200: 1-2000: 1.

The invention also discloses a process system for realizing the method, which comprises a reactant mixing unit, a hydrogenation catalytic reaction unit and a product rectification unit;

the reactant mixing unit comprises a coal tar fuel tank, a biomass grease fuel tank and a mixing tank, wherein the coal tar fuel tank and the biomass grease fuel tank are respectively connected into a feeding port of the mixing tank through pipelines; the hydrogenation catalytic reaction unit comprises a fixed bed reactor I, a fixed bed reactor II, an oil-water separation tank, a fixed bed reactor III and a fixed bed reactor IV which are sequentially communicated through pipelines, and air inlet branch pipes for introducing hydrogen are arranged on the fixed bed reactor I, the fixed bed reactor II, the fixed bed reactor III and the fixed bed reactor IV; the product rectifying unit comprises a product rectifying tower, a diesel product tank and a gasoline product tank, and a discharge port of the product rectifying tower is connected to the diesel product tank and the gasoline product tank through pipelines;

a discharge port of the mixing tank is connected into a feed port I of the fixed bed reactor through a pipeline, and a discharge port of the fixed bed reactor IV is connected into a feed port of the product rectifying tower through a pipeline.

Preferably, the process system is provided with a main gas inlet pipe for introducing hydrogen, and a hydrogen gas outlet pipeline is arranged on the fixed bed reactor IV; the total gas inlet pipe is respectively communicated with the hydrogen inlet branch pipes on the fixed bed reactor I, the fixed bed reactor II, the fixed bed reactor III and the fixed bed reactor IV, and the hydrogen outlet pipeline on the fixed bed reactor IV is connected to the total gas inlet pipe in a returning mode to form a circulation loop of hydrogen.

Preferably, a drain pipe is arranged on the oil-water separation tank; and a pipeline led out of the product rectifying tower is connected back to the fixed bed reactor III.

Preferably, the coal tar fuel tank and the biomass grease fuel tank are respectively provided with a pressure pump on the connecting pipeline of the mixing tank feeding port.

Compared with the prior art, the invention has the following beneficial effects:

the invention discloses a method for preparing gasoline and diesel oil by coal tar and biomass grease through co-hydrogenation, which comprises the steps of mixing the coal tar and the biomass grease to obtain mixed oil serving as a raw material, carrying out catalytic hydrogenation reaction to form a hydrogen supply solvent, enabling hydrogen free radicals provided in the catalytic hydrogenation saturation process of aromatic hydrocarbons contained in the coal tar to act on the biomass grease, reacting the hydrogen free radicals with unsaturated carboxyl functional groups contained in the biomass grease, and carrying out hydrodeoxygenation to generate straight-chain alkane without carboxyl. The method is characterized in that a self-hydrogen supply phenomenon exists in the coal tar hydrogenation process, the coal tar contains benzene compounds and naphthalene compounds, the benzene compounds and the naphthalene compounds are subjected to cracking reaction through hydrogenation reaction, so that the content of the benzene compounds and the naphthalene compounds is reduced, and the benzene compounds and the naphthalene compounds are continuously subjected to hydrogenation saturation catalytic reaction with hydrogen. Finally, the gasoline and diesel oil products are obtained through rectification treatment and separation.

Therefore, the method for preparing the gasoline and diesel oil by the coal tar and the biomass grease through the co-hydrogenation has the following advantages:

1. the mixed hydrogenation technology of coal tar and biomass oil relieves the problem of raw material supply in the single raw material hydrogenation technology to a certain extent, and in the traditional coal tar hydrogenation technology, the coal tar raw material has high heavy component content and high viscosity, is difficult to convey in actual production, is easy to block pipelines and equipment, and is difficult to continuously produce for a long time; secondly, the coal tar has high content of unsaturated hydrocarbon, high content of heteroatom compounds, high hydrogen consumption and high difficulty in hydrogenation. And the coal tar and the biomass grease are subjected to hydrogenation together, so that the damage to the device can be reduced, and the method has the advantages of reducing the cost and saving resources.

2. The conventional biomass oil hydrogenation process has the advantages of low hydrogenation efficiency of oxygenated compounds, less raw materials, single adaptability of the process to the raw materials and no large-scale continuous production potential. And hydrogen free radicals generated in the coal tar hydrogenation process can promote the hydrogenation of the biomass grease, and compared with the hydrogenation of single biomass grease, the method has the advantages of high efficiency, waste utilization and the like.

3. Compared with a single raw material hydrogenation technology, the mixed hydrogenation preparation method has high adaptability to raw materials.

Furthermore, by arranging a plurality of catalytic hydrogenation reaction stages and carrying out sectional reaction aiming at each unsaturated component in the coal tar, hydrogen free radicals in the hydrogen supply solvent can fully react with the unsaturated functional groups, and the co-hydrogenation reaction efficiency of the coal tar and the biomass grease is improved.

The invention discloses a process system for realizing the method for preparing gasoline and diesel oil by coal tar and biomass grease through co-hydrogenation, wherein in the process system, the component proportion of mixed oil can be adjusted by arranging a coal tar fuel tank and a biomass grease fuel tank; by arranging the staged fixed bed reactor, the staged control of the catalytic hydrogenation reaction can be realized, and the reaction efficiency of the co-hydrogenation is improved; an oil-water separation tank is arranged between the fixed bed reactors II and III, which is beneficial to the separation of by-product water, improves the reaction efficiency and ensures the purity of the product; the staged fixed bed reactors are provided with the gas inlet branch pipes for introducing the hydrogen, so that the hydrogen in the reaction process can be kept in a constant pressure state, and the reaction is favorably carried out.

Furthermore, a hydrogen outlet pipeline is arranged, and a total gas inlet pipe for introducing hydrogen is connected with a gas inlet branch pipe for introducing the hydrogen on the staged fixed bed reactor to form a circulation loop of the hydrogen, so that the constant pressure condition of the reaction is ensured, and the utilization rate of the hydrogen is increased.

Furthermore, by arranging the drain pipe on the oil-water separation tank, the byproduct water can be separated from the reaction system in time; the product rectification tower is connected with the fixed bed reactor III in a return mode through a leading-out pipeline, so that the utilization rate of reactants can be improved, the raw material cost input is saved, and the product preparation efficiency is improved.

Drawings

Fig. 1 is a technical route diagram of the present invention.

Wherein: 1-coal tar raw material tank; 2-biomass grease raw material tank; 3-a pressure pump; 4-a pressure pump 5-a mixing tank; 6-fixed bed reactor I; 7-fixed bed reactor II; 8-an oil-water separation tank; 9-fixed bed reactor III; 10-fixed bed reactor IV; 11-product rectification column; 12-a diesel product tank; 13-a gasoline product tank; 14-total intake pipe; 15-drainage pipeline.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The method for preparing the gasoline and diesel oil by using the coal tar and the biomass grease through the co-hydrogenation comprises the following steps:

1) coal tar and biomass oil enter a mixing tank to be mixed, and a material flow I is obtained from the bottom of the mixing tank; the material flow I directly enters the step 2);

2) carrying out catalytic hydrogenation on the obtained material flow I, and conveying the hydrogenated material flow II to the step 3);

3) deeply hydrogenating the material flow II obtained in the step 2), and conveying the hydrogenated material flow III to the step 4);

4) feeding the material flow III obtained in the step 3) into an oil-water separation tank for separation, and obtaining a material flow IV from the bottom of the oil-water separation tank; said stream goes directly to step 5);

5) carrying out catalytic hydrogenation on the material flow IV obtained in the step 4), and conveying the hydrogenated material flow V to a step 6);

6) catalytically hydrogenating the material flow V obtained in the step 5), and conveying the hydrogenated material flow VI to a step 7);

7) preparing the stream VI obtained in the step 6) into gasoline and diesel according to a conventional process;

8) conveying the stream VII (incompletely reacted mixture stream) obtained in the step 7) to the step 5) for recycling.

Referring to fig. 1, it can be seen that the invention also discloses a process system for implementing the method for preparing gasoline and diesel oil by using coal tar and biomass oil through co-hydrogenation, which comprises a reactant mixing unit, a hydrogenation catalytic reaction unit and a product rectification unit;

the reactant mixing unit comprises a coal tar fuel tank 1, a biomass grease fuel tank 2 and a mixing tank 5, wherein the coal tar fuel tank 1 and the biomass grease fuel tank 2 are respectively connected into a feeding port of the mixing tank 5 through pipelines, a pressure pump I3 is arranged on a connecting pipeline of the coal tar fuel tank 1 and the feeding port of the mixing tank 5, and a pressure pump II 4 is arranged on a connecting pipeline of the biomass grease fuel tank 2 and the feeding port of the mixing tank 5; the hydrogenation catalytic reaction unit comprises a fixed bed reactor I6, a fixed bed reactor II 7, an oil-water separation tank 8, a fixed bed reactor III 9 and a fixed bed reactor IV 10 which are sequentially communicated through pipelines, air inlet branch pipes for introducing hydrogen are arranged on the fixed bed reactor I6, the fixed bed reactor II 7, the fixed bed reactor III 9 and the fixed bed reactor IV 10, and a water outlet pipe 15 is arranged on the oil-water separation tank 8; the product rectifying unit comprises a product rectifying tower 11, a diesel product tank 12 and a gasoline product tank 13, wherein a discharge port of the product rectifying tower 11 is connected to the diesel product tank 12 and the gasoline product tank 13 through pipelines; wherein, the discharge hole of the mixing tank 5 is connected with the feeding hole of the fixed bed reactor I6 through a pipeline, the discharge hole of the fixed bed reactor IV 10 is connected with the feeding hole of the product rectifying tower 11 through a pipeline, and the outlet pipeline on the product rectifying tower 11 is connected back to the fixed bed reactor III 9.

The process system is provided with a main gas inlet pipe 14 for introducing hydrogen, and a hydrogen gas outlet pipeline is arranged on the fixed bed reactor IV 10; the total gas inlet pipe 14 is respectively communicated with hydrogen inlet branch pipes on the fixed bed reactor I6, the fixed bed reactor II 7, the fixed bed reactor III 9 and the fixed bed reactor IV 10, and a hydrogen outlet pipeline on the fixed bed reactor IV 10 is connected to the total gas inlet pipe 14 in a return mode to form a circulation loop of hydrogen. In combination with the preparation method and the process system, in the method for preparing gasoline and diesel oil by using coal tar and biomass oil through co-hydrogenation, the specific implementation manner of the step 2) is as follows:

2.1) the material flow I generated by the mixing tank 5 enters a fixed bed reactor I6 through a heating furnace, and the temperature is 200-265 ℃, the reaction pressure is 8-12 MPa, and the airspeed is 0.8-1.6 h^-1The total airspeed is 0.25-0.40 h^-1Under the condition that the hydrogen-oil ratio is 1200: 1-2000: 1, the raw material in the material flow I contacts with a catalyst in a fixed bed reactor I6, and a product flow II is generated after reaction;

2.2) carrying out reaction of olefin hydrogenation saturation to produce straight-chain alkane by the material flow I through a fixed bed reactor I6, and generating a material flow II after the reaction;

2.3) the material flow II obtained in the step 2.1) enters a fixed bed reactor II 7 after passing through a heat exchanger;

during the reaction, the total hydrogen supplement amount is 3% of the raw material flow, the fixed bed reactor I6 comprises 5 beds, each bed is provided with a hydrogen inlet, and the hydrogen supplement amount is 10% of the total amount so as to ensure the proper concentration of hydrogen in the reactant.

The catalyst adopted by the fixed bed reactor I6 in the step 2.1) is as follows: hydrogenation protectant (HG), hydrodemetallization agent (HDM), loading: hydro protectant (HG): total catalyst 2: 21; hydrodemetallization (HDM) catalyst in a total catalyst ratio of 1:7, wherein the HG catalyst satisfies the following conditions:

a) support for HG catalyst: gamma-Al₂O₃；

b) Hydrogenation active component of HG catalyst: 3-4% of Ni and 2-3% of Si are used as hydrogenation active components of the catalyst;

c) the aperture distribution of the HG catalyst is 20-25% in terms of 2-5 nm, 30-60% in terms of 5-10 nm and 10-15% in terms of more than 10 nm;

d) the pore volume of the HG catalyst is 0.34-0.44 cm³/g；

The HDM catalyst satisfies the following conditions:

a) HDM catalystThe vector of (2): gamma-Al₂O₃；

b) Hydrogenation active component of HDM catalyst: 13-15% of Mo and 4-5% of Ni are used as hydrogenation active components of the catalyst;

c) the pore diameter distribution of the HDM catalyst is 20-25% in 2-5 nm, 30-60% in 5-10 nm and 10-15% in more than 10 nm;

d) the pore volume of the HDM catalyst is 0.39-0.49 cm³/g；

The specific implementation manner of the step 3) is as follows:

3.1) passing the material flow II through a heat exchanger, entering a fixed bed reactor II 7, and reacting at the temperature of 300-340 ℃, the reaction pressure of 8-12 MPa and the airspeed of 0.8-1.6 h^-1The total airspeed is 0.25-0.40 h^-1Under the condition that the volume ratio of hydrogen to oil is 1200: 1-2000: 1, the raw material in the material flow II is in contact with a first hydrogenation catalyst in a fixed bed reactor II 7 for deep hydrogenation, and a material flow III is generated after the reaction;

3.2) carrying out naphthalene hydrogenation on the material flow II through a fixed bed reactor II 7 to produce dihydronaphthalene and carrying out hydrogenation deoxidation on phenol to produce cyclohexane, and reacting to generate a material flow III;

3.3) introducing the material flow III obtained in the step 3.1) into an oil-water separation tank;

during the reaction, the total hydrogen supplement amount is 3% of the flow of the raw materials, the fixed bed reactor II 7 is 5 beds in total, each section of bed is provided with a hydrogen inlet, and the hydrogen supplement amount is 30% of the total amount so as to ensure the proper concentration of hydrogen in the reactants;

the catalyst adopted by the fixed bed reactor II 7 is as follows: a first hydrofining agent (HF-1) with the loading of: the total amount of the first hydrofining agent and the catalyst is 6:21, and the catalyst meets the following conditions:

a) support for HF-1 catalyst: gamma-Al₂O₃；

b) Hydrogenation active component of HF-1 catalyst: 23-24% -4-5% of W is used as a hydrogenation active component of the catalyst;

c) the pore diameter distribution of the HF-1 catalyst is less than 10nm and accounts for 1-5%, 10-20 nm and 10-15%, 20-50 nm and more than 50%, and 20-30%, 50%;

d) HF-1 catalysisThe pore volume of the agent is 0.55-0.65 cm³/g；

The specific implementation manner of the step 5) is as follows:

5.1) passing the material flow IV through a heat exchanger, entering a fixed bed reactor III 9, and reacting at the temperature of 330-^-1The total airspeed is 0.25-0.40 h^-1Under the condition that the volume ratio of hydrogen to oil is 1200: 1-2000: 1, the raw material in the material flow IV contacts with a hydrogenation catalyst 2 in a fixed bed reactor III 9, deep hydrogenation is carried out, and a material flow V is generated after reaction;

5.2) the material flow IV passes through a fixed bed reactor III 9 to carry out the reaction of producing tetrahydronaphthalene by hydrogenation saturation of dihydronaphthalene and the reaction of producing tetrahydroanthracene by hydrogenation saturation of anthracene, and a material flow V is generated after the reaction;

5.3) the material flow V obtained in the step 5.1) enters a fixed bed reactor IV 10 after passing through a heat exchanger;

in the reaction period, the total hydrogen supplement amount is 3% of the flow of the raw materials, the fixed bed reactor III 9 is 5 beds in total, each section of bed is provided with a hydrogen inlet, and the hydrogen supplement amount is 40% of the total amount so as to ensure the proper concentration of hydrogen in the reactants;

the catalyst adopted by the fixed bed reactor III 9 is as follows: a second hydrofining agent (HF-2) with the loading of: the total amount of the second hydrofining agent and the catalyst is 5:21, and the catalyst meets the following conditions:

a) support for HF-2 catalyst: gamma-Al₂O₃；

b) Hydrogenation active component of HF-2 catalyst: mo 21-22% -Ni 6-7% -P2-3% -Si 4-5% as a hydrogenation active component of the catalyst;

c) the pore diameter distribution of the HF-2 catalyst is less than 10nm and accounts for 1-5%, 10-20 nm and 10-15%, 20-50 nm and more than 50%, and 20-30%, 50%;

d) the pore volume of the HF-2 catalyst is 0.55-0.65 cm³/g；

The specific implementation manner of the step 6) is as follows:

6.1) passing the material flow V through a heat exchanger, entering a fixed bed reactor IV 10, and reacting at the temperature of 330-370 ℃, the reaction pressure of 8-12 MPa and the airspeed of 0.8-1.6 h^-1The total airspeed is 0.25-0.40 h^-1Under the condition that the volume ratio of hydrogen to oil is 1200: 1-2000: 1, the raw material in the material flow V is in contact with a hydrogenation catalyst 2 in a fixed bed reactor IV 10, deep hydrogenation is carried out, and a material flow VI is generated after reaction;

6.2) the material flow V is subjected to hydrogenation saturation of tetrahydronaphthalene through a fixed bed reactor III 9 to form hydrogenation saturation reaction of decahydronaphthalene and benzene, and a material flow VI is generated after the reaction;

6.3) the material flow VI obtained in the step 6.1) enters a product rectifying tower 11 after passing through a heat exchanger.

During the reaction, the total hydrogen supplement amount is 3% of the flow of the raw materials, the fixed bed reactor IV 10 is 5 beds in total, each bed is provided with a hydrogen inlet, and the hydrogen supplement amount is 20% of the total amount so as to ensure the proper concentration of hydrogen in the reactants;

the catalyst adopted by the fixed bed reactor IV 10 is as follows: a second hydrofining agent (HF-2) with the loading of: and (3) hydrofining agent II, wherein the total amount of the catalyst is 5:21, and the catalyst meets the following conditions:

a) support for HF-2 catalyst: gamma-Al₂O₃；

c) the pore size distribution of the HF-2 catalyst is less than 10nm and accounts for 1-5%, 10-20 nm and 10-15%, 20-50 nm and more than 50%, and 20-30%, and 50% respectively;

d) the pore volume of the HF-2 catalyst is 0.55-0.65 cm³/g；

The traditional coal tar hydrogenation reaction is to reduce the contents of sulfur, nitrogen, oxygen, olefin and aromatic hydrocarbon through the reactions of demetalization, desulfurization, denitrification, deoxidation, olefin saturation, aromatic hydrocarbon saturation and the like under the action of high temperature, high pressure, hydrogen and a catalyst, and the main reaction is as follows.

1 hydrodesulfurization reaction

Mercaptan: RSH + H₂→RH+H₂S

Thioether: RSR' +2H₂→RH+R′H+H₂S

Disulfide: RSSR' +3H₂→RH+R′H+2H₂S

Thiophene:

bis-Benzophosphenes:

2 hydrodenitrogenation reaction

Alkyl amine: R-NH₂+H₂→RH+NH₃

Nitriles: RCN^-+3H₂→RCH₃+NH₃

Pyrrole:

indole:

pyridine:

and (3) quindox:

3 hydrodeoxygenation reaction

Naphthenic acid:

phenols:

furan:

4 olefin saturation reaction

Olefin (b):R-CH＝CH₂+H₂→R-CH₂-CH₃

5 aromatic saturation reaction

Benzene:

nano:

phenanthrene:

the invention utilizes the phenomenon of self-hydrogen supply in the coal tar hydrogenation process, and the phenomenon can be used for biomass grease hydrogenation. The coal tar contains benzene compounds, the benzene compounds are subjected to cracking reaction through hydrogenation reaction, so that the content of the benzene compounds is reduced, benzene rings are continuously saturated by hydrogen to form saturated aromatic hydrocarbons, the hydrogenation saturation of the aromatic hydrocarbons is a reversible reaction, the hydrogenation can form saturated hydrocarbons, and the dehydrogenation can form hydrogen radicals. The hydrogen radical can be used for realizing the hydrodeoxygenation of the fatty acid, so that the fatty acid has two reaction paths.

In the process, the invention utilizes the phenomenon of self-hydrogen supply in the coal tar hydrogenation process, and the phenomenon can be used for biomass grease hydrogenation. A study (medium-low temperature coal tar hydro-conversion path) shows that part of tricyclic compounds are subjected to cracking reaction through hydrogenation reaction, the cracking reaction degree of the tricyclic compounds is far greater than that of the naphthalene compounds, so that the content of the naphthalene compounds is not reduced, hydrogenated naphthalene in a product mainly exists in a tetrahydronaphthalene form, and part of the tetrahydronaphthalene is continuously subjected to hydrogenation saturation and converted into decahydronaphthalene. Both tetrahydronaphthalene and decahydronaphthalene are excellent hydrogen donating solvents and thus form a self-donating phenomenon.

Tetrahydronaphthalene and decahydronaphthalene generated by coal tar hydrogenation can also be used as hydrogen supply solvents for biomass oil hydrogenation, and hydrogen radicals provided by the hydrogen supply solvents provide a new path for biomass oil hydrogenation.

The coal tar and the biological oil are subjected to the co-hydrogenation, so that a new path is provided for the hydrogenation of the biological oil, the hydrogenation rate of the biological oil is accelerated, tetrahydronaphthalene and decahydronaphthalene are consumed, the coal tar hydrogenation is a reversible reaction, the product is consumed, the forward reaction rate is increased according to the nature of the reversible reaction, and the hydrogenation rate of the coal tar is also accelerated. The process utilizes the hydrogen supply effect of the coal tar to widen the source of the raw materials.

The present invention will be further described with reference to the following specific examples:

the invention takes coal tar and biomass grease as raw materials, and the properties of the coal tar are shown in table 1. The hydrogenation conditions for examples 1-4 are shown in Table 2, together with the corresponding catalysts in Table 3. Coal tar and biomass oil are mixed and fed for 10t/h (7.2 multiplied by 10)⁴t/a), the flow rate and related properties of each material flow in the reaction process are shown in Table 4, the flow rate of the hydrogen supply for each reactor in the reaction process is shown in Table 5, and the detailed properties of the products obtained in the examples are shown in Table 6.

TABLE 1 Properties of coal tar

TABLE 2 hydrogenation reaction conditions for each reactor

Table 3 catalyst for each reactor of examples 1-4

TABLE 4 Hydrogen make-up for each reactor

TABLE 5 relevant Properties of the various streams (coal tar feed 10t/h)

TABLE 6 detailed Properties of hydrocarbons in the products obtained in examples 1-4

Item	Example 1	Example 2	Example 3	Example 4
					Product yield/%	88.98	89.25	90.85	91.32
Nitrogen content/μ g^-1	35.02	34.20	35.67	35.11
					Sulfur content// μ g · g^-1	29.31	28.72	28.50	27.82
Saturated hydrocarbon content/%)	86.76	89.196	91.01	94.806
					Tricyclic aromatic hydrocarbon content/%)	0.29	0.325	0.258	0.128
Bicyclic aromatic content/%	8.21	6.218	5.286	3.257
					Monocyclic aromatic content/%)	2.29	2.895	2.582	1.415
Percent of pectin	1.3	1.4	1.4	1.5
					Asphaltene content/%)	Trace amount of	Trace amount of	Trace amount of	Trace amount of

By implementing the method, the gasoline and diesel oil are successfully prepared from the coal tar and the biomass oil through the co-hydrogenation, the hydrogen free radicals separated from the coal tar in the hydrogenation saturation process are fully utilized and act on the fatty acid of the biomass oil, and the ideal process effect is achieved. It can be seen from Table 6 that the yield of aromatic hydrocarbons in the product obtained in example 4 reached 91.32%. In examples 2 and 3, under the condition that the composition of the catalyst in example 1 is not changed, the reaction conditions are changed, the product yield is 89.25 percent and 90.85 percent respectively, and the reaction conditions of the reactor in each stage are in the best state by comparing the catalyst used in example 4 and the reaction conditions thereof, and the whole system equipment runs stably, so that a considerable development prospect is shown.

The following are specific embodiments of the above examples 1 to 4:

example 1

At 7.2X 10⁴And (3) performing hydrogenation on the t/a (10t/h) coal tar and the biomass oil to obtain gasoline and diesel oil. Mixing coal tar and biomass oil, feeding the mixture into a hydrofining device, wherein the process conditions of the hydrofining device are shown in tables 2 to 5, and separating, hydrofining and raw material preparationObtaining hydrofined diesel oil and hydrofined gasoline rich in a large amount of saturated aromatic hydrocarbons by oil forming

In the embodiment, the coal tar and the biomass oil are mixed to form a fixed bed hydrocracking mixed raw material, and the hydrocracking process adopts the method as follows: the method comprises the following steps of (1) carrying out a hydrogenation reaction on coal tar and biomass oil together:

a. coal tar and biomass grease slurry preparation: feeding the mixture according to the flow ratio of 5: 5, mixing the coal tar and the biomass grease uniformly under the stirring condition of 80-200 ℃ to prepare the raw material.

b. Raw materials generated by the mixing tank 5 enter a fixed bed reactor I6 through a heating furnace and a pressure pump, and the reaction pressure is 8MPa at the temperature of 200 ℃ and the airspeed is 1.05h^-1The total space velocity is 0.25h^-1And under the condition that the volume ratio of hydrogen to oil is 2000:1, the filling amounts of the raw materials and the fixed bed reactor I6 are respectively as follows: 9.14m³The hydrogenation protective agent (HG) and the hydrogenation demetallization agent (HDM) are contacted to carry out the reaction of producing straight chain alkane by the hydrogenation saturation of olefin, and the product after the reaction has a material flow II with the saturated hydrocarbon content of 5.368 percent and the aromatic hydrocarbon content of 21.675 percent. Feeding the material flow II into a fixed bed reactor II 7 through a heat exchanger and a pressure pump, and reacting at the temperature of 300 ℃, the reaction pressure of 8MPa and the airspeed of 0.80h^-1The total space velocity is 0.25h^-1The filling amount of the raw material in the material flow II and the fixed bed reactor II 7 is 10.97m under the condition that the volume ratio of hydrogen to oil is 2000:1³The first hydrofining agent (HF-1) is contacted with the first hydrofining agent to perform naphthalene hydrogenation to produce dihydronaphthalene and perform hydrodeoxygenation on phenol to produce cyclohexane, and a material flow III with the saturated hydrocarbon content of 64.33% and the aromatic hydrocarbon content of 25.12% is generated after the reaction. And the obtained material flow III is discharged from the oil-water separation tank to react with the production water to obtain a material flow IV. The material flow IV enters a fixed bed reactor III 9 through a heat exchanger and a pressure pump, the reaction pressure is 8MPa at the temperature of 330 ℃, and the space velocity is 1.05h^-1The total space velocity is 0.25h^-1The filling amount of the raw material in the material flow IV and the fixed bed reactor III 9 is 9.14m under the condition that the volume ratio of hydrogen to oil is 2000:1³The second hydrofining agent (HF-2) is contacted with the first hydrofining agent to carry out a reaction of producing tetrahydronaphthalene by hydrogenation saturation of dihydronaphthalene and a reaction of producing tetrahydroanthracene by hydrogenation saturation of anthracene, and after the reaction, the produced saturated hydrocarbon with the content of 72.42 percent and aromatic hydrocarbonStream V with a hydrocarbon content of 23.89%. Passing the material flow V through a heat exchanger, entering a fixed bed reactor IV 10, and reacting at the temperature of 330 ℃, the reaction pressure of 8MPa and the space velocity of 1.05h^-1The total space velocity is 0.25h^-1The filling amount of the raw material in the material flow V and the fixed bed reactor IV 10 is 9.14m under the condition that the volume ratio of hydrogen to oil is 2000:1³The second hydrofining agent (HF-2) is contacted with the first hydrofining agent to carry out hydrogenation saturation of tetrahydronaphthalene to form hydrogenation saturation reaction of decahydronaphthalene and benzene, and a material flow VI with the saturated hydrocarbon content of 86.76 percent and the aromatic hydrocarbon content of 10.79 percent is generated after the reaction. And introducing the obtained material flow VI into a rectifying tower to obtain diesel oil and gasoline with the saturated aromatic hydrocarbon content of 86.76%.

Example 2

Based on the first example, the ratio of the feed flow rates was adjusted to 4:6, the reactor conditions were changed to 220, 320, 350 ℃ C, 9MPa for the reaction pressure, and 0.3h for the total space velocity^-1And the volume ratio of hydrogen to oil is 1700:1, and diesel oil and gasoline with the saturated aromatic hydrocarbon content of 89.196 percent are produced.

Compared with the first embodiment, after changing the feeding ratio, the temperature, the pressure, the space velocity and the hydrogen-oil volume ratio, the obtained product is better than the first embodiment.

Example 3

Based on the first example, the ratio of the feed flow rates was adjusted to 3:7, the reactor conditions were changed to 240, 330, 360 ℃ C, 10MPa for the reaction pressure, and 0.35h for the total space velocity^-1And the volume ratio of hydrogen to oil is 1500:1, and diesel oil and gasoline with the saturated aromatic hydrocarbon content of 91.01 percent are produced.

Example 4

Based on the first example, the ratio of the feeding flow is adjusted to 2:8, the conditions of each reactor are changed to the temperature (265, 340, 370 and 370) DEG C, the reaction pressure is 12MPa, and the total space velocity is 0.4h^-1And the volume ratio of hydrogen to oil is 1200:1, and diesel oil and gasoline with the saturated aromatic hydrocarbon content of 94.806 percent are produced.

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A method for preparing gasoline and diesel oil by using coal tar and biomass oil through co-hydrogenation is characterized in that the coal tar and the biomass oil are mixed to obtain mixed oil, the mixed oil is subjected to catalytic hydrogenation reaction, and then is rectified to obtain a gasoline and diesel oil product;

2. The method for preparing gasoline and diesel oil by using coal tar and biomass grease through co-hydrogenation according to claim 1, which is characterized by comprising the following steps:

1) mixing coal tar with biomass grease to obtain a material flow I;

4) separating water in the material flow III to obtain a material flow IV;

3. The method for preparing gasoline and diesel oil by using coal tar and biomass oil through co-hydrogenation according to claim 2, wherein in the step 1), the mixing mass ratio of the coal tar to the biomass oil is (5-2) to (5-8).

4. The method for preparing gasoline and diesel oil by using coal tar and biomass grease through co-hydrogenation according to claim 2, wherein the catalytic reaction of olefin hydrogenation to generate linear paraffin in the step 2) comprises the following specific reaction conditions: the reaction temperature is 200-265 ℃, the reaction pressure is 8-12 MPa, and the space velocity is 0.8-1.6 h^-1The total airspeed is 0.25-0.40 h^-1The volume ratio of the hydrogen to the oil is 1200: 1-2000: 1.

5. The method for preparing gasoline and diesel oil by using coal tar and biomass grease through co-hydrogenation according to claim 2, wherein the catalytic reaction of naphthalene hydrogenation to generate dihydronaphthalene and the catalytic reaction of phenol hydrogenation to generate cyclohexane in the step 3) are performed under specific reaction conditions including: the reaction temperature is 300-340 ℃, the reaction pressure is 8-12 MPa, and the space velocity is 0.8-1.6 h^-1The total airspeed is 0.25-0.40 h^-1And the volume ratio of the hydrogen to the oil is 1200: 1-2000: 1.

6. The method for preparing gasoline and diesel oil by using coal tar and biomass grease through co-hydrogenation according to claim 2, wherein the catalytic reaction in the step 5) and the step 6) comprises the following specific reaction conditions: the reaction temperature is 330-370 ℃, the reaction pressure is 8-12 MPa, and the space velocity is 0.8-1.6 h^-1The total airspeed is 0.25-0.40 h^-1And the volume ratio of the hydrogen to the oil is 1200: 1-2000: 1.

7. A process system for implementing the method of any one of claims 1 to 6, wherein the process system comprises a reactant mixing unit, a hydrogenation catalytic reaction unit and a product rectification unit;

the reactant mixing unit comprises a coal tar fuel tank (1), a biomass grease fuel tank (2) and a mixing tank (5), wherein the coal tar fuel tank (1) and the biomass grease fuel tank (2) are respectively connected into a feeding port of the mixing tank (5) through pipelines; the hydrogenation catalytic reaction unit comprises a fixed bed reactor I (6), a fixed bed reactor II (7), an oil-water separation tank (8), a fixed bed reactor III (9) and a fixed bed reactor IV (10) which are sequentially communicated through pipelines, and gas inlet branch pipes for introducing hydrogen are arranged on the fixed bed reactor I (6), the fixed bed reactor II (7), the fixed bed reactor III (9) and the fixed bed reactor IV (10); the product rectifying unit comprises a product rectifying tower (11), a diesel product tank (12) and a gasoline product tank (13), and a discharge port of the product rectifying tower (11) is connected to the diesel product tank (12) and the gasoline product tank (13) through pipelines;

wherein, the discharge hole of the mixing tank (5) is connected with the feeding hole of the fixed bed reactor I (6) through a pipeline, and the discharge hole of the fixed bed reactor IV (10) is connected with the feeding hole of the product rectifying tower (11) through a pipeline.

8. The process system according to claim 7, wherein the process system is provided with a main gas inlet pipe (14) for introducing hydrogen, and a hydrogen outlet pipeline is arranged on the fixed bed reactor IV (10); the total gas inlet pipe (14) is respectively communicated with the hydrogen inlet branch pipes on the fixed bed reactor I (6), the fixed bed reactor II (7), the fixed bed reactor III (9) and the fixed bed reactor IV (10), and the hydrogen outlet pipeline on the fixed bed reactor IV (10) is connected to the total gas inlet pipe (14) in a return mode to form a circulation loop of hydrogen.

9. The process system as claimed in claim 7, wherein the oil-water separation tank (8) is provided with a drain pipe (15); a pipeline led out from the product rectifying tower (11) is connected back to the fixed bed reactor III (9).

10. The process system according to claim 7, wherein a pressurizing pump is arranged on each connecting pipeline of the coal tar fuel tank (1), the biomass grease fuel tank (2) and the feeding port of the mixing tank (5).