CN108085041B

CN108085041B - Method for producing light oil by biomass liquefaction

Info

Publication number: CN108085041B
Application number: CN201711421658.XA
Authority: CN
Inventors: 林科; 李林; 郭立新
Original assignee: Beijing SJ Environmental Protection and New Material Co Ltd
Current assignee: Beijing Haixin Energy Technology Co ltd
Priority date: 2017-12-25
Filing date: 2017-12-25
Publication date: 2020-07-17
Anticipated expiration: 2037-12-25
Also published as: CN108085041A

Abstract

The invention relates to the field of biological energy, in particular to a method for producing light oil by liquefying biomass, which comprises the specific preparation steps of drying, primarily crushing, compressing and secondarily crushing vegetable oil residues in sequence, mixing the mixture with a hydrogenation catalyst and a vulcanizing agent to obtain a mixture, adding the mixture into solvent oil, grinding and pulping to obtain biomass slurry with the vegetable oil residue concentration of 50-65wt percent, initiatively carrying out the treatment process of firstly compressing and then secondarily crushing the vegetable oil residues, compressing the biomass to ensure that loose vegetable oil residues are subjected to the stages of rearrangement, mechanical deformation and the like, so that the density and the specific gravity of the vegetable oil residues are increased, the vegetable oil residues are favorably dispersed in oil products, the content of the vegetable oil residues in the oil products can be improved, the concentration of reaction materials is increased, the conveying capacity of the biomass in unit time by a pump is improved, the stable operation and the conveying of the pump are ensured.

Description

Method for producing light oil by biomass liquefaction

Technical Field

The invention belongs to the technical field of biomass liquefaction, and particularly relates to a method for producing light oil by biomass liquefaction.

Background

All organic matters capable of growing are collectively called as biomass, and in a broad sense, the biomass refers to all plants and microorganisms, animals taking the plants and the microorganisms as food and waste produced by the animals; in a narrow sense, biomass mainly refers to plant oil residue such as soybean oil residue except grains and fruits in the agriculture and forestry production process, lignocellulose (short for lignin) such as trees, agricultural product processing leftovers, agriculture and forestry wastes, livestock and poultry manure and wastes in the animal husbandry production process, and the like. Typical biomass materials are crop plants, crop wastes, wood wastes, animal wastes, and the like. The biomass can be used as food and industrial raw materials, and can improve the environment and adjust the climate, and in addition, the biomass also has the characteristics of renewability, low pollution and wide distribution, so that the biomass becomes an important component of renewable energy, therefore, how to efficiently develop and utilize the biomass energy plays a very positive role in solving the problems of energy and ecological environment. The liquefied oil obtained by directly liquefying biomass is an important component in biomass resource utilization. The mechanism of liquefaction of biomass is as follows: biomass is first cracked into oligomers, which are then dehydrated, dehydroxylated, dehydrogenated, deoxygenated and decarboxylated to form small molecule compounds, which are then reacted via condensation, cyclization, polymerization, etc. to produce new compounds. At present, biomass liquefaction technologies can be mainly divided into two major categories, namely indirect liquefaction and direct liquefaction, wherein the biomass direct liquefaction technology is to directly liquefy biomass from solid to liquid at proper temperature and pressure by adopting hydrolysis and supercritical liquefaction or introducing hydrogen, inert gas and the like under the action of a solvent or a catalyst. For example, chinese patent document CN103540414A discloses a method for refining biodiesel from palm oil residue and acidified oil, which comprises preheating palm oil residue and acidified oil into liquid, feeding the liquid palm oil residue and acidified oil into an electric heating furnace by a high temperature oil pump, heating, evaporating water at 200 ℃., evaporating oil vapor at 380 ℃ and 220 ℃., converting the oil vapor into short-chain fatty acid with carbon number below 18 after passing through a cracking catalyst pipeline, esterifying the short-chain fatty acid, and finally converting the esterified short-chain fatty acid into biodiesel.

The process realizes the conversion from the vegetable oil residue to the biological oil. In the above technology, on one hand, the slurry formed by the palm oil residue and the acidified oil needs to be conveyed to the cracking catalyst pipeline by a pump, and most of the vegetable oil residues have low specific gravity due to rich porosity, so that the vegetable oil residues are difficult to dissolve in the solvent oil, and the concentration of the vegetable oil residues in the slurry is low, so that the conveying amount of the pump to the vegetable oil residues in unit time is limited, and the process has low production efficiency, high industrial cost and high energy consumption; on the other hand, the vegetable oil residue with porosity is easy to float on the surface of the solvent oil, and the viscosity of the acidified oil used as the slurry solvent is high, so that the slurry is difficult to flow, the conveying pipeline is easy to block, and the stable transportation of the pump is difficult to realize. In the prior art, the concentration and the dispersibility of the vegetable oil residue in the slurry are improved by adding a dispersing agent into the slurry, but the quality of the prepared bio-oil is influenced by adding the dispersing agent.

Therefore, how to improve the existing biomass cracking catalysis process to increase the concentration of the plant oil residue in the slurry, improve the conveying capacity of the pump to the plant oil residue in unit time, realize the stable transportation of the pump and reduce the energy consumption is still a technical problem to be solved.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to overcome the defects of small conveying capacity, unstable transportation and high energy consumption of the pump to the biomass in the existing biomass cracking catalytic process, and further provide a method for producing light oil by biomass liquefaction.

The technical scheme adopted by the invention for solving the problems is as follows:

a method for producing light oil by biomass liquefaction comprises the following steps:

(1) mixing biomass, a hydrogenation catalyst, a vulcanizing agent and solvent oil to prepare biomass slurry;

(2) carrying out a first liquefaction reaction on the biomass slurry and hydrogen, and collecting a first reaction product;

(3) carrying out a second liquefaction reaction on the first reaction product and hydrogen, and collecting a second reaction product;

(4) carrying out first separation on the second reaction product, and collecting a light component and a heavy component;

(5) carrying out reduced pressure distillation on the heavy components, and collecting light fractions;

(6) mixing the light component and the light fraction to carry out hydrogenation reaction, and collecting a hydrogenation product;

(7) fractionating the hydrogenation product to obtain light oil;

in the step (1), the biomass is vegetable oil residue, and the preparation of the biomass slurry comprises the steps of drying, primary crushing, compressing and secondary crushing the vegetable oil residue in sequence, mixing the crushed vegetable oil residue with the hydrogenation catalyst and the vulcanizing agent to obtain a mixture, adding the mixture into the solvent oil, and grinding and pulping to obtain the slurry with the vegetable oil residue concentration of 50-65 wt%.

The vegetable oil residue in the invention can be one or more of palm oil residue, soybean oil residue, peanut oil residue, saponin oil residue, linseed oil residue, castor oil residue, rapeseed oil residue or olive oil residue.

In the step of preparing the biomass slurry, the pressure for compressing the vegetable oil residue is 3-5MPa, and the temperature is 40-60 ℃.

The preparation step of the slurryIn the step, the drying temperature of the vegetable oil residue is 80-110 ℃, the drying time is 2-6h, and the water content of the dried vegetable oil residue is lower than 2 wt%; the median particle size after primary crushing is 100-; the median particle size after the secondary crushing is 30-50 mu m, and the bulk density after the secondary crushing is 1500-³。

The viscosity of the slurry was 300-700mPa ∙ s (50 ℃).

The grinding pulping is stirring pulping, dispersing pulping, emulsifying pulping, shearing pulping or homogenizing pulping.

The solvent oil is one or more of waste animal and vegetable oil, waste mineral oil, mineral oil or distillate oil.

Further, the waste animal and vegetable oil is one or more of waste oil, hogwash oil or rancid oil;

the waste mineral oil is one or two of waste lubricating oil or waste engine oil;

the mineral oil is one or more of heavy oil, residual oil, anthracene oil or wash oil.

The mass ratio of the biomass to the hydrogenation catalyst to the vulcanizing agent is 100: (0.5-5): (0.1-0.4).

In the step (2), the reaction conditions of the first liquefaction reaction are as follows:

the reaction temperature is 380-460 ℃;

the reaction pressure is 15-25 MPa;

the gas-liquid ratio is 800-1600L/kg;

the space velocity of the biomass slurry is 0.4-2h^-1。

In the step (3), the reaction conditions of the second liquefaction reaction are as follows:

the reaction temperature is 390-490 ℃;

the reaction pressure is 15-25 MPa;

the gas-liquid ratio is 700-1600L/kg;

the space velocity of the biomass slurry is 0.3-2h^-1。

In the step (5), the temperature of the reduced pressure distillation is 320-400 ℃, and the pressure is 5-20 kPa.

In the step (6), the reaction conditions of the hydrogenation reaction are as follows:

the reaction temperature is 400-470 ℃;

the reaction pressure is 15-20 MPa;

the volume ratio of hydrogen to oil is 800-1500;

the space velocity is 0.4-2h^-1。

In the step (8), the temperature of the fractionation is 340-390 ℃.

And collecting distillate oil obtained after the vacuum distillation step and heavy fraction obtained in the fractionation step, and taking the distillate oil and the heavy fraction as the solvent oil.

Before fractionation, the hydrogenation product also comprises a step of carrying out secondary separation on the hydrogenation product to respectively obtain hydrogen, gas-phase light hydrocarbon and a liquid phase, wherein the hydrogen is circularly used in the first liquefaction reaction, the second liquefaction reaction and the hydrogenation reaction.

In the step (1), the temperature of the mixing step is 25-180 ℃.

The hydrogenation catalyst is at least one of the following catalysts:

1) amorphous iron oxide and/or amorphous iron oxyhydroxide;

2) the amorphous alumina is loaded with active ingredients, the active ingredients are at least one of VIB metal, VIIB metal or VIII metal oxides, and the content of the active ingredients is 10-25 wt%.

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

(1) the invention provides a method for producing light oil by liquefying biomass, which comprises the steps of preparing biomass slurry, drying, primarily crushing, compressing and secondarily crushing vegetable oil residues in sequence, mixing the mixture with a hydrogenation catalyst and a vulcanizing agent to obtain a mixture, adding the mixture into solvent oil, grinding and pulping to obtain the slurry with the vegetable oil residue concentration of 50-65 wt%, wherein the invention initiatively performs a treatment process of firstly compressing and then secondarily crushing the vegetable oil residues, and the loose vegetable oil residues are subjected to the stages of re-arrangement such as collapse, closure and the like and mechanical deformation by compressing the vegetable oil residues, so that the volume of the vegetable oil residues is greatly reduced, the porosity of the vegetable oil residues is reduced, the density and the specific gravity of the vegetable oil residues are increased, the vegetable oil residues are favorably dispersed in oil products, the content of the vegetable oil residues in the oil products is increased, and the concentration of reaction materials is increased, the content of the plant oil residue in the slurry can reach 50-65 wt%, and meanwhile, the increase of the biomass concentration in the slurry inevitably improves the conveying capacity of the pump to the plant oil residue in unit time, so that the efficiency of the whole biomass liquefaction process is improved, and the industrial cost and energy consumption are reduced; in addition, the increase of the specific gravity of the vegetable oil residues is also beneficial to the suspension and dispersion of the vegetable oil residues in the slurry, so that the viscosity of the biomass slurry can be reduced, the smooth flowing of the slurry after the biomass slurrying in a pipeline is realized, the blockage of the pipeline is avoided, the stable running and conveying of a pump are realized, and meanwhile, high-viscosity waste oil which cannot be used as a biomass liquefaction solvent in the prior art, such as waste engine oil, illegal cooking oil, rancidity oil and the like, can also be utilized.

Mixing biomass, a hydrogenation catalyst, a vulcanizing agent and solvent oil to prepare biomass slurry; then, sequentially carrying out a first liquefaction reaction and a second liquefaction reaction on the biomass slurry and the hydrogen, collecting a second reaction product, and ensuring that the biomass is fully liquefied into a liquid phase through two liquefaction reactions so as to improve the yield of liquid oil; then separating the second reaction product, and collecting light components and heavy components; then carrying out reduced pressure distillation on the heavy components, and collecting light fractions; then mixing the light component and the light fraction for hydrogenation reaction; the separation of light components and heavy components is realized through three continuous steps of separation, reduced pressure distillation and hydrogenation reaction, light fractions mixed in the heavy components are separated from the heavy components through reduced pressure distillation, meanwhile, heavy fractions difficult to be hydrogenated and liquefied are separated out, so that the subsequent conversion of light oil is not influenced, then the light fractions and the light components are mixed for hydrogenation reaction, a small amount of heavy components which are easy to be changed into light components in the light components can be converted into the light components through hydrogenation reaction, the yield of the light oil is improved, particularly the yield of low-boiling-point oil in the light oil, such as naphtha and the like, the residue in the light oil is enriched and agglomerated as much as possible by separating and distilling the biomass oil in advance, and then the residue is removed from the bottom of a reduced pressure distillation device, so that the residue content in the subsequent light oil is reduced; and finally, fractionating the hydrogenation product to obtain light oil, heavy oil and oil residue. Through test, the biomass conversion rate of the method is more than or equal to 99 percent, the yield of the light bio-oil with the distillation range below 520 ℃ is 70-80 percent, and the residue content in the light bio-oil is less than 0.1 percent by weight.

(2) According to the method for producing the light oil by liquefying the biomass, provided by the invention, the compression temperature is controlled to be 40-60 ℃, the rheological property of the plant oil residues can be obviously enhanced by compressing the plant oil residues at the temperature, and the viscosity of the biomass slurry is reduced.

(3) The method for producing the light oil by biomass liquefaction further comprises the step of collecting distillate oil obtained after the vacuum distillation step and heavy fraction obtained in the fractionation step, and taking the distillate oil and the heavy fraction as the solvent oil.

(4) According to the method for producing the light oil by liquefying the biomass, provided by the embodiment of the invention, before fractionation, the hydrogenated product further comprises a step of carrying out secondary separation on the hydrogenated product to respectively obtain hydrogen, gas-phase light hydrocarbon and a liquid phase, wherein the hydrogen can be circularly used in the first liquefaction reaction, the second liquefaction reaction and the hydrogenation reaction.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic process flow diagram of the method for producing light oil by biomass liquefaction according to the invention.

Reference numerals:

1-a vulcanizing agent; 2-biomass; 3-a hydrogenation catalyst; 4-a biomass slurry tank; 5-a suspended bed reactor; 6-internal circulation suspension bed reactor; 7-suspension bed hydrogenation products; 8-a hot high pressure separator; 9-light component; 10-heavy ends; 11-a high differential pressure relief valve; 12-a vacuum column; 13-overhead oil; 14-measuring line distillate oil; 15-fixed bed hydrogenation reactor; 16-fixed bed hydrogenation product; 17-a separator; 18-hydrogen; 19-gas phase light hydrocarbons; 20-distillate oil; 21-a fractionation column; 22-biomass naphtha; 23-biodiesel; 24-biomass tower bottoms oil; 25-residue; 26-hydrogen.

Detailed Description

To better illustrate the objects, aspects and advantages of the present invention, the present invention will be further described with reference to specific embodiments. This invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art, and the present invention will only be defined by the appended claims.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Example 1

The embodiment provides a method for producing light oil by biomass liquefaction, which comprises the following steps as shown in figure 1:

(1) feeding rapeseed oil residue and olive oil residue into a dryer, drying at 80 deg.C for 3 hr until the water content is less than 2 wt%, primarily pulverizing in a superfine pulverizer to obtain a median particle size of 100 μm, and feeding the primarily pulverized rapeseed oil residue and olive oil residue into a plodder at 50 deg.C under 3MPaCompressing and extruding under force, performing secondary pulverization treatment, and obtaining mixed granule 2 of rapeseed oil residue and olive oil residue with median particle diameter of 30 μm, wherein the bulk density of the mixed granule 2 is 1500kg/m³；

Mixing the mixed particles 2, amorphous alumina 3 loaded with Mo oxide and Ni oxide (the particle diameter is 5-50 μm, the loading is 10 wt%), and sulfur 1 according to the mass ratio of 100: 0.5: 0.4, uniformly mixing the mixture in a biomass slurry tank 4 to obtain a mixture, adding the mixture into illegal cooking oil, uniformly mixing the mixture at the temperature of 100 ℃, and stirring and pulping the mixture to form biomass slurry with the biomass content of 65 wt%, wherein the viscosity of the slurry is 700mPa ∙ s (50 ℃) for later use;

(2) carrying out a first liquefaction reaction on the biomass slurry and additional hydrogen 26 in a suspended bed reactor 5, and collecting a first reaction product, wherein the parameters of the first liquefaction reaction are that the reaction temperature is 380 ℃, the reaction pressure is 25MPa, the gas-liquid ratio is 800L/kg, and the space velocity of the biomass slurry is 2h^-1；

(3) Carrying out a second liquefaction reaction on the first reaction product and hydrogen in an internal circulation suspension bed reactor 6, and collecting a second reaction product, namely a suspension bed hydrogenation product 7, wherein the parameters of the second liquefaction reaction are that the reaction temperature is 390 ℃, the reaction pressure is 25MPa, the gas-liquid ratio is 700L/kg, and the space velocity of the biomass slurry is 1h^-1；

(4) Carrying out first separation on the second reaction product in a hot high-pressure separator 8 under the pressure of 19MPa, and collecting a light component 9 and a heavy component 10;

(5) the heavy component 10 is depressurized by a high-pressure-difference depressurization valve 11 and then enters a depressurization tower 12, reduced-pressure distillation is carried out at the temperature of 320 ℃ and the pressure of 20kPa, light fractions, namely, tower top oil 13 and measurement line distillate oil 14 in the depressurization tower 12 are collected, the measurement line distillate oil 14 is returned to the step (1) to be used as solvent oil 1, and residue 25 is recovered from the bottom of the depressurization tower 12;

(6) mixing the light component 9 with the tower top oil 13, feeding the mixture into a fixed bed hydrogenation reactor 16 for hydrogenation reaction, and collecting a fixed bed hydrogenation product 16, wherein the hydrogenation reaction conditions are as follows: reaction ofThe temperature is 400 ℃, the reaction pressure is 20MPa, the volume ratio of hydrogen to oil is 800, and the space velocity is 2h^-1；

(7) The fixed bed hydrogenation product 16 enters a separator 17 for second separation to obtain hydrogen 18, gas-phase light hydrocarbon 19 and liquid phase, namely distillate oil 20, wherein the hydrogen 18 can be used in the first liquefaction reaction, the second liquefaction reaction and the hydrogenation reaction, and the gas-phase light hydrocarbon 19 is recycled;

(8) the distillate oil 20 enters a fractionating tower 21 and is fractionated at 360 ℃, naphtha is separated from the top of the tower, diesel oil is separated from the middle upper part of the tower, and bottom oil 24, namely heavy fraction, is discharged from the bottom of the tower and is returned to the step (1) as the solvent oil 1.

Through test, the conversion rate of the biomass is 95%, wherein the yield of the light biomass oil with the distillation range below 520 ℃ is 75%, and the residue content in the light biomass oil is 0.09 wt%;

elemental analysis of the obtained light biomass oil revealed that the light biomass oil had an organic carbon content of 80 wt%, an organic hydrogen content of 19.5 wt%, and an organic oxygen content of 0.5 wt%.

Example 2

The embodiment provides a method for producing light oil by biomass liquefaction, which comprises the following steps:

(1) the palm oil residue and the castor oil residue are sent into a dryer to be dried for 2 hours at 100 ℃ until the water content is lower than 2 wt%, then sent into a superfine pulverizer to be primarily pulverized, the median particle size after primary pulverization is 300 mu m, then the primarily pulverized palm oil residue and castor oil residue are sent into a plodder to be compressed and extruded at the temperature of 60 ℃ and under the pressure of 5MPa, then secondary pulverization is carried out, the mixed particles 2 of the palm oil residue and the castor oil residue with the median particle size of 50 mu m are obtained after secondary pulverization, and the bulk density of the mixed particles 2 is 1600kg/m³；

Mixing the mixed particles 2, amorphous alumina 3 (with the particle diameter of 100-150 μm and the loading of 25%) loaded with W oxide and Pd oxide and carbon disulfide 1 according to the mass ratio of 100: 5:0.1, uniformly mixing the mixture in a biomass slurry tank 4 to obtain a mixture, adding the mixture into mixed oil of waste lubricating oil and residual oil, uniformly mixing the mixture at 180 ℃, and then performing dispersed pulping to form biomass slurry with the biomass content of 55 wt%, wherein the viscosity of the slurry is 300mPa ∙ s (50 ℃) for later use;

(2) carrying out a first liquefaction reaction on the biomass slurry and additional hydrogen 26 in a suspended bed reactor 5, and collecting a first reaction product, wherein the parameters of the first liquefaction reaction are that the reaction temperature is 460 ℃, the reaction pressure is 15MPa, the gas-liquid ratio is 1600L/kg, and the space velocity of the biomass slurry is 0.4h^-1；

(3) Carrying out a second liquefaction reaction on the first reaction product and hydrogen in an internal circulation suspension bed reactor 6, and collecting a second reaction product, namely a suspension bed hydrogenation product 7, wherein the parameters of the second liquefaction reaction are that the reaction temperature is 490 ℃, the reaction pressure is 15MPa, the gas-liquid ratio is 1600L/kg, and the space velocity of the biomass slurry is 0.3h^-1；

(4) Carrying out first separation on the second reaction product in a hot high-pressure separator 8 under the pressure of 15MPa, and collecting a light component 9 and a heavy component 10;

(5) reducing the pressure of the heavy component 10 by a high-pressure-difference pressure reducing valve 11, then feeding the heavy component into a pressure reducing tower 12, carrying out reduced pressure distillation at the temperature of 400 ℃ and the pressure of 5kPa, collecting light fractions, namely tower top oil 13 and line-measuring distillate oil 14 in the pressure reducing tower 12, returning the line-measuring distillate oil 14 to the step (1) to be used as solvent oil 1, and recovering residue 25 from the bottom of the pressure reducing tower 12;

(6) mixing the light component 9 with the tower top oil 13, feeding the mixture into a fixed bed hydrogenation reactor 16 for hydrogenation reaction, and collecting a fixed bed hydrogenation product 16, wherein the hydrogenation reaction conditions are as follows: the reaction temperature is 470 ℃, the reaction pressure is 15MPa, the hydrogen-oil volume ratio is 1500, and the space velocity is 0.4h^-1；

(8) the distillate oil 20 enters a fractionating tower 21 and is fractionated at 390 ℃, naphtha is separated from the top of the tower, diesel oil is separated from the middle upper part of the tower, and bottom oil 24, namely heavy fraction, is discharged from the bottom of the tower and is returned to the step (1) as the solvent oil 1.

Through test, the conversion rate of the biomass is 100 percent, wherein the yield of the light biomass oil with the distillation range below 520 ℃ is 70 percent, and the residue content in the light biomass oil is 0.08 percent by weight;

elemental analysis of the obtained light biomass oil revealed that the light biomass oil had an organic carbon content of 90 wt%, an organic hydrogen content of 9.5 wt%, and an organic oxygen content of 0.5 wt%.

Example 3

(1) feeding fructus Gleditsiae Abnormalis oil residue into a drier, drying at 110 deg.C for 6 hr until the water content is lower than 2 wt%, primarily pulverizing in a superfine pulverizer to obtain a median particle diameter of 200 μm, feeding the primarily pulverized fructus Gleditsiae Abnormalis oil residue into a plodder, compression-extruding at 40 deg.C under 4MPa, and secondarily pulverizing to obtain fructus Gleditsiae Abnormalis oil residue particles 2 with median particle diameter of 40 μm, wherein the bulk density of the particles 2 is 1550kg/m³；

Mixing the particles 2, amorphous alumina loaded with Mn oxide (the particle size is 100-150 μm, the loading amount is 15%), amorphous iron oxide and sulfur according to the mass ratio of 100:2: 2: 0.3 evenly mixing the mixture in a biomass slurry tank 4 to obtain a mixture, adding the mixture into mixed oil formed by heavy oil and hogwash oil, evenly mixing the mixture at 25 ℃, and then emulsifying and pulping the mixture to form biomass slurry with the biomass content of 50 wt%, wherein the viscosity of the biomass slurry is 485mPa ∙ s (50 ℃) for later use;

(2) carrying out a first liquefaction reaction on the biomass slurry and additional hydrogen 26 in a suspended bed reactor 5, and collecting a first reaction product, wherein the parameters of the first liquefaction reaction are that the reaction temperature is 390 ℃, the reaction pressure is 17MPa, the gas-liquid ratio is 1000L/kg, and the space velocity of the biomass slurry is 0.7h^-1；

(3) Carrying out a second liquefaction reaction on the first reaction product and hydrogen in an internal circulation suspension bed reactor 6, and collecting a second reaction product, namely a suspension bed hydrogenation product 7, wherein the parameters of the second liquefaction reaction are that the reaction temperature is 450 ℃, the reaction pressure is 20MPa, the gas-liquid ratio is 1000L/kg, and the space velocity of the biomass slurry is 2h^-1；

(5) reducing the pressure of the heavy component 10 by a high-pressure-difference pressure reducing valve 11, then feeding the heavy component into a pressure reducing tower 12, carrying out reduced pressure distillation at the temperature of 380 ℃ and the pressure of 10kPa, collecting light fractions, namely tower top oil 13 and line-measuring distillate oil 14 in the pressure reducing tower 12, returning the line-measuring distillate oil 14 to the step (1) to be used as solvent oil 1, and recovering residue 25 from the bottom of the pressure reducing tower 12;

(6) mixing the light component 9 with the tower top oil 13, feeding the mixture into a fixed bed hydrogenation reactor 16 for hydrogenation reaction, and collecting a fixed bed hydrogenation product 16, wherein the hydrogenation reaction conditions are as follows: the reaction temperature is 400 ℃, the reaction pressure is 18MPa, the hydrogen-oil volume ratio is 1500, and the space velocity is 1.5h^-1；

Through test, the conversion rate of the biomass is 98%, wherein the yield of the light biomass oil with the distillation range below 520 ℃ is 80%, and the residue content in the light biomass oil is 0.09 wt%;

elemental analysis of the obtained light biomass oil revealed that the light biomass oil had an organic carbon content of 85 wt%, an organic hydrogen content of 13 wt%, and an organic oxygen content of 2 wt%.

Example 4

(1) drying soybean oil residue in a drier at 90 deg.C for 5.0 hr until the water content is lower than 2 wt%, primarily pulverizing in a superfine pulverizer to obtain a median particle diameter of 150 μm, compression-extruding at 45 deg.C under 2.5MPa in a plodder, secondarily pulverizing to obtain soybean oil residue granule 2 with median particle diameter of 35 μm, and the bulk density of the granule 2 is 1515kg/m³And is ready for use;

uniformly mixing the particles 2 with amorphous iron oxyhydroxide 3 and dimethyl disulfide 1 in a mass ratio of 100:4:0.2 in a biomass slurry tank 4 to obtain a mixture, adding the mixture into mixed oil of wash oil and distillate oil, uniformly mixing at 100 ℃, and then performing shearing pulping to form biomass slurry with the biomass content of 60 wt%, wherein the viscosity of the slurry is 610mPa ∙ s (50 ℃) for later use;

(2) carrying out a first liquefaction reaction on the biomass slurry and additional hydrogen 26 in a suspended bed reactor 5, and collecting a first reaction product, wherein the parameters of the first liquefaction reaction are that the reaction temperature is 450 ℃, the reaction pressure is 23MPa, the gas-liquid ratio is 1500L/kg, and the space velocity of the biomass slurry is 1.8h^-1；

(3) Carrying out a second liquefaction reaction on the first reaction product and hydrogen in an internal circulation suspension bed reactor 6, and collecting a second reaction product, namely a suspension bed hydrogenation product 7, wherein the parameters of the second liquefaction reaction are that the reaction temperature is 475 ℃, the reaction pressure is 24MPa, the gas-liquid ratio is 1400L/kg, and the space velocity of the biomass slurry is 1.5h^-1；

(4) Carrying out first separation on the second reaction product in a hot high-pressure separator 8 under the pressure of 22MPa, and collecting a light component 9 and a heavy component 10;

(5) the heavy component 10 is depressurized by a high-pressure-difference depressurization valve 11 and then enters a depressurization tower 12, the pressure is reduced and distilled at the temperature of 380 ℃ and the pressure of 8kPa, light fractions, namely tower top oil 13 and line-measuring distillate oil 14 in the depressurization tower 12 are collected, and residue 25 is recovered from the bottom of the depressurization tower 12;

(6) mixing the light component 9 with the tower top oil 13, feeding the mixture into a fixed bed hydrogenation reactor 16 for hydrogenation reaction, and collecting a fixed bed hydrogenation product 16, wherein the hydrogenation reaction conditions are as follows: the reaction temperature is 460 ℃, the reaction pressure is 18MPa, the volume ratio of hydrogen to oil is 1300, and the space velocity is 1.6h^-1；

(8) the distillate oil 20 enters a fractionating tower 21 and is fractionated at 390 ℃, naphtha is separated from the top of the tower, diesel oil is separated from the middle upper part of the tower, and bottom oil 24, namely heavy fraction, is discharged from the bottom of the tower.

Through test, the conversion rate of the biomass is 97 percent, wherein the yield of the light biomass oil with the distillation range below 520 ℃ is 76 percent, and the residue content in the light biomass oil is 0.09 percent by weight;

Example 5

(1) feeding the castor oil residues into a dryer, drying for 4 hours at 104 ℃ until the water content is lower than 2 wt%, then feeding the castor oil residues into a superfine pulverizer to be primarily pulverized, wherein the median particle size after primary pulverization is 250 mu m, then feeding the castor oil residues after primary pulverization into a briquetting machine, performing compression and extrusion molding at the temperature of 55 ℃ and under the pressure of 4.5MPa, then performing secondary pulverization treatment, and obtaining castor oil residue particles 2 with the median particle size of 45 mu m after secondary pulverization, wherein the bulk density of the castor oil residue particles 2 is 1582kg/m³Ready for use。

Uniformly mixing the castor oil residue particles 2, the amorphous iron oxide, the amorphous iron oxyhydroxide and the sulfur 1 in a biomass slurry tank 4 according to the mass ratio of 100:2:1.5:0.1 to obtain a mixture, adding the mixture into mixed oil of residual oil and waste engine oil, uniformly mixing at 100 ℃, and then performing homogeneous pulping to form biomass slurry with the biomass content of 63 wt%, wherein the viscosity of the slurry is 386mPa ∙ s (50 ℃) for later use;

(2) carrying out a first liquefaction reaction on the biomass slurry and additional hydrogen 26 in a suspended bed reactor 5, and collecting a first reaction product, wherein the parameters of the first liquefaction reaction are that the reaction temperature is 420 ℃, the reaction pressure is 21MPa, the gas-liquid ratio is 1300L/kg, and the space velocity of the biomass slurry is 1.1h^-1；

(3) Carrying out a second liquefaction reaction on the first reaction product and hydrogen in an internal circulation suspension bed reactor 6, and collecting a second reaction product, namely a suspension bed hydrogenation product 7, wherein the parameters of the second liquefaction reaction are that the reaction temperature is 470 ℃, the reaction pressure is 24MPa, the gas-liquid ratio is 1500L/kg, and the space velocity of the biomass slurry is 1.6h^-1；

(4) Carrying out first separation on the second reaction product in a hot high-pressure separator 8 under the pressure of 21MPa, and collecting a light component 9 and a heavy component 10;

(5) reducing the pressure of the heavy component 10 by a high-pressure-difference pressure reducing valve 11, then feeding the heavy component into a pressure reducing tower 12, carrying out reduced pressure distillation at the temperature of 330 ℃ and the pressure of 11kPa, collecting light fractions, namely tower top oil 13 and line-measuring distillate oil 14 in the pressure reducing tower 12, returning the line-measuring distillate oil 14 to the step (1) to be used as solvent oil 1, and recovering residue 25 from the bottom of the pressure reducing tower 12;

(6) mixing the light component 9 with the tower top oil 13, feeding the mixture into a fixed bed hydrogenation reactor 16 for hydrogenation reaction, and collecting a fixed bed hydrogenation product 16, wherein the hydrogenation reaction conditions are as follows: the reaction temperature is 455 ℃, the reaction pressure is 20MPa, the volume ratio of hydrogen to oil is 1300, and the space velocity is 0.5h^-1；

(8) the distillate oil 20 enters a fractionating tower 21 and is fractionated at 380 ℃, naphtha is separated from the top of the tower, diesel oil is separated from the middle upper part of the tower, and bottom oil 24, namely heavy fraction, is discharged from the bottom of the tower and is returned to the step (1) as the solvent oil 1.

Through experimental tests, the conversion rate of biomass is 99%, wherein the yield of light biomass oil with the distillation range below 520 ℃ is 78%, and the residue content in the light biomass oil is 0.07 wt%;

elemental analysis of the obtained light biomass oil revealed that the light biomass oil had an organic carbon content of 83 wt%, an organic hydrogen content of 16 wt%, and an organic oxygen content of 1 wt%.

Example 6

(1) drying soybean oil residue in a drier at 95 deg.C for 3.5 hr until the water content is lower than 2 wt%, primarily pulverizing in an ultrafine pulverizer to obtain a median particle size of 300 μm, compressing and extruding the soybean oil residue in a plodder at 60 deg.C under 5MPa, secondarily pulverizing to obtain soybean oil residue particles 2 with median particle size of 50 μm, wherein the bulk density of the soybean oil residue particles 2 is 1589kg/m³；

Mixing the soybean oil residue particles 2, the amorphous ferric oxide 3 and the sulfur 1 according to a mass ratio of 100: 4.5: 0.1, uniformly mixing the mixture in a biomass slurry tank 4 to obtain a mixture, adding the mixture into anthracene oil, uniformly mixing the mixture at the temperature of 30 ℃, and then performing dispersed pulping to form biomass slurry with the biomass content of 59 wt%, wherein the viscosity of the slurry is 301mPa ∙ s (50 ℃) for later use;

(2) carrying out a first liquefaction reaction on the biomass slurry and the added hydrogen 26 in the suspension bed reactor 5, and collecting a first reaction product, wherein the parameters of the first liquefaction reaction are as follows: the reaction temperature is 450 DEG CThe reaction pressure is 21MPa, the gas-liquid ratio is 1100L/kg, and the space velocity of the biomass slurry is 2h^-1；

(3) Carrying out a second liquefaction reaction on the first reaction product and hydrogen in an internal circulation suspension bed reactor 6, and collecting a second reaction product, namely a suspension bed hydrogenation product 7, wherein the parameters of the second liquefaction reaction are that the reaction temperature is 480 ℃, the reaction pressure is 16MPa, the gas-liquid ratio is 1600L/kg, and the space velocity of the biomass slurry is 0.3h^-1；

(6) mixing the light component 9 with the tower top oil 13, feeding the mixture into a fixed bed hydrogenation reactor 16 for hydrogenation reaction, and collecting a fixed bed hydrogenation product 16, wherein the hydrogenation reaction conditions are as follows: the reaction temperature is 430 ℃, the reaction pressure is 19MPa, the hydrogen-oil volume ratio is 1200, and the space velocity is 0.9h^-1；

Through test, the conversion rate of the biomass is 96%, wherein the yield of the light biomass oil with the distillation range below 520 ℃ is 73%, and the residue content in the light biomass oil is 0.09 wt%;

elemental analysis of the obtained light biomass oil revealed that the light biomass oil had an organic carbon content of 88 wt%, an organic hydrogen content of 10.5 wt%, and an organic oxygen content of 1.5 wt%.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims

1. A method for producing light oil by biomass liquefaction comprises the following steps: (1) mixing biomass, a hydrogenation catalyst, a vulcanizing agent and solvent oil to prepare biomass slurry; (2) carrying out a first liquefaction reaction on the biomass slurry and hydrogen, and collecting a first reaction product; (3) carrying out a second liquefaction reaction on the first reaction product and hydrogen, and collecting a second reaction product; (4) carrying out first separation on the second reaction product, and collecting a light component and a heavy component; (5) carrying out reduced pressure distillation on the heavy components, and collecting light fractions; (6) mixing the light component and the light fraction to carry out hydrogenation reaction, and collecting a hydrogenation product; (7) fractionating the hydrogenation product to obtain light oil; in the step (1), the biomass is vegetable oil residue, and the preparation of the biomass slurry comprises the steps of drying, primary crushing, compressing and secondary crushing the vegetable oil residue in sequence, mixing the crushed vegetable oil residue with the hydrogenation catalyst and the vulcanizing agent to obtain a mixture, adding the mixture into the solvent oil, and grinding and pulping to obtain the slurry with the vegetable oil residue concentration of 50-65 wt%;

wherein the pressure for compressing the vegetable oil residue is 3-5MPa, and the temperature is 40-60 ℃;

2. According to the claimsThe method for solving the problem 1 is characterized in that in the preparation step of the slurry, the drying temperature of the vegetable oil residue is 80-110 ℃, the drying time is 2-6h, and the water content of the dried vegetable oil residue is lower than 2 wt%; the median particle size after primary crushing is 100-; the median particle size after the secondary crushing is 30-50 mu m, and the bulk density after the secondary crushing is 1500-³。

3. The method according to any one of claims 1 to 2, wherein in the step (1), the mass ratio of the biomass to the hydrogenation catalyst to the vulcanizing agent is 100: 0.5-5: 0.1-0.4.

4. The method as claimed in claim 1 or 2, wherein in the step (2), the reaction conditions of the first liquefaction reaction are that the reaction temperature is 380-460 ℃, the reaction pressure is 15-25MPa, the gas-liquid ratio is 800-1600L/kg, and the space velocity of the biomass slurry is 0.4-2h^-1。

5. The method as claimed in claim 1, wherein in the step (3), the reaction conditions of the second liquefaction reaction are 390-490 ℃, the reaction pressure is 15-25MPa, the gas-liquid ratio is 700-1600L/kg, and the space velocity of the first reaction product is 0.3-2h^-1。

6. The method as claimed in claim 1 or 5, wherein the temperature of the reduced pressure distillation in step (5) is 320 ℃ and 400 ℃, and the pressure is 5-20 kPa.

7. The method according to claim 1, wherein in the step (6), the reaction conditions of the hydrogenation reaction are as follows: the reaction temperature is 400-470 ℃; the reaction pressure is 15-20 MPa; the volume ratio of hydrogen to oil is 800-1500; the space velocity is 0.4-2h^-1。

8. The method as claimed in claim 1 or 7, wherein the temperature of the fractionation in step (7) is 340-390 ℃.

9. The method of claim 1, further comprising the step of collecting a distillate obtained after the vacuum distillation step and a heavy fraction obtained in the fractionation step, and using the distillate and the heavy fraction as the solvent oil.

10. The method of claim 1 or 9, wherein the hydrogenation product is further subjected to a second separation step before fractionation to obtain hydrogen, a light hydrocarbon gas phase and a liquid phase, wherein the hydrogen is recycled for the first liquefaction reaction, the second liquefaction reaction and the hydrogenation reaction.

11. The method according to claim 1, wherein the temperature of the mixing step in step (1) is 25-180 ℃.

12. The process of claim 1, wherein the hydrogenation catalyst is at least one of the following catalysts: 1) amorphous iron oxide and/or amorphous iron oxyhydroxide; 2) the amorphous alumina is loaded with active ingredients, the active ingredients are at least one of VIB metal, VIIB metal or VIII metal oxides, and the content of the active ingredients is 10-25 wt%.