CN108179019B

CN108179019B - Multistage liquefaction process for coal and biomass

Info

Publication number: CN108179019B
Application number: CN201711429943.6A
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: 2017-12-26
Filing date: 2017-12-26
Publication date: 2020-03-10
Anticipated expiration: 2037-12-26
Also published as: CN108179019A

Abstract

The invention relates to the technical field of clean energy, and particularly provides a coal and biomass multistage liquefaction process. The biomass coal water slurry which has high solid content and can be stably conveyed by a pump is successfully obtained by firstly carrying out compression, crushing and re-crushing on the coal and biomass raw materials and then preparing slurry. The coal and biomass are hydrolyzed under high pressure and high temperature, and the hydrolysis products are subjected to primary cracking, hydrogenation reaction, deep cracking and hydrogenation reaction in sequence under the action of hydrogen and a first catalyst and a second catalyst, so that the conversion of the coal and biomass into bio-oil and the refining of the bio-oil are realized. In the process, the conversion rate of the biomass and the coal can reach 97-99%, the yield of the bio-oil can reach 70-80%, and the residue amount is less than 3%.

Description

Multistage liquefaction process for coal and biomass

Technical Field

The invention relates to the technical field of clean energy, in particular to a co-refining process of coal and biomass.

Background

At present, coal is used as a main energy source in China, the traditional coal utilization mode is combustion, but the problem of air pollution caused by coal combustion is increasingly serious; moreover, the coal quality of China is lowered year by year, so that the raw coal washing proportion is improved year by year, and the coal washing wastewater brings serious water pollution. The severe environmental problems have made the adjustment of energy structures one of the important tasks in energy development in our country. However, the storage condition of energy resources of China is poor oil and rich coal, a large amount of oil imports are needed to meet the production development requirement every year, if the energy structure of China is adjusted by reducing the utilization of coal resources, the energy resources with rich reserves are left, the importation amount of oil is also greatly increased, and the energy safety of China is certainly influenced.

The energy structure adjustment mode more suitable for the national conditions of China is to realize the clean and efficient utilization of coal resources. Among them, coal liquefaction technology is included. The kerosene co-refining technology is a coal liquefaction technology which is developed recently, and becomes a research hotspot for clean utilization of coal. For example, chinese patent document CN102191072 discloses a coal liquefaction technology for kerosene co-refining, which first prepares coal particles and oil into a suspension, makes the suspension pass through two serially connected boiling beds with catalyst and hydrogen added to perform liquefaction reaction, and then sends the obtained lighter components into a fixed bed reactor for further hydrogenation reaction to finally obtain naphtha, kerosene and/or diesel oil, and heavy components. The reaction conditions in the two boiling beds are 325-420 ℃, 16-20 MPa, 350-450 ℃ and 16-20 MPa in sequence, and the temperature of the second boiling bed is always higher than that of the first boiling bed by more than 10 ℃; the reaction conditions of the fixed bed reactor are 250-480 ℃ and 2-25 MPa.

However, this technology has the following problems in common with most kerosene mixing processes in the prior art:

1. limited efficiency of liquefaction

The kerosene slurry prepared from coal powder and oil is required to be conveyed into a cracking hydrogenation device by a pump, in order to ensure the stable operation and conveying of the pump, the viscosity of the kerosene slurry cannot be too high, and heavy oil, residual oil and the like which are used as dispersing agents in the kerosene slurry are all viscous liquids, so that the coal powder in the kerosene slurry cannot be too high in the kerosene co-refining technology, the concentration of reaction materials is limited, and the liquefaction efficiency is low.

2. Large hydrogen consumption

The mechanism of coal hydrocracking is as follows:

in the first stage, coal is pyrolyzed to form pre-asphaltene and asphaltene, and gas, liquefied oil and macromolecular polycondensate are generated.

In the second stage, under the condition of rich hydrogen, partial pre-asphaltene is hydrogenated to generate liquefied oil, and partial macromolecular polycondensate is hydrogenated and cracked again to generate liquefied oil with low molecular weight.

When the temperature is too high or the hydrogen supply is insufficient, the pre-asphaltenes and some of the insoluble organics in the asphaltenes can form char or semi-coke. The high concentration and high partial pressure of hydrogen are favorable for forward hydrocracking reaction of coal and reducing coke formation. The kerosene co-refining technology tends to consume a high amount of hydrogen.

In order to improve the liquefaction efficiency, researchers have been working on increasing the content of pulverized coal in kerosene slurry, for example, trying to reduce the particle size of pulverized coal as much as possible in order to increase the proportion of pulverized coal by increasing the dispersibility of pulverized coal in kerosene slurry. However, the pulverized coal has a large amount of pore structure, and the operation of reducing the particle size of the pulverized coal exposes the minute pores further, thereby adsorbing a large amount of water. As a result, the viscosity of kerosene slurry prepared from pulverized coal of smaller particle size is higher than that of kerosene slurry prepared from pulverized coal of larger particle size at the same pulverized coal weight ratio, and smooth transportation of the pump cannot be achieved at all.

Researchers have also tried to liquefy coal by using water instead of oil as a hydrogen supply solvent, and a technical paper "direct hydrogenation liquefaction performance of lignite under water or tetralin medium" discloses a technical scheme for performing hydrogenation liquefaction of lignite by using water as a medium, wherein the technical scheme is that the hydrogenation liquefaction reaction of lignite is performed in an autoclave at 380 ℃, when FeS is used as a catalyst and hydrogen is used as an atmosphere, the total conversion rate of lignite is only 40.6%, and the oil gas yield and the asphaltene yield are 39.2% and 1.4% respectively. This is because of hydrogen supply and dissolved H of water itself₂The conversion rate of lignite is low because the capacity of lignite is weak and the requirement of pyrolysis and hydrogenation of coal cannot be fully met.

In order to reduce the consumption of hydrogen, researchers have attempted to utilize biomass with coal for pyrolysis hydrogenation. The hydrogen source for reaction with cracked coal fines in the kerosene co-refining technology comes mainly from: the hydrogen dissolved in the solvent oil is converted into active hydrogen under the action of a catalyst, the hydrogen which can be supplied or transferred by the solvent oil, the active hydrogen generated by the cracking of the coal and the hydrogen generated by the reaction. However, the H/C ratio of biomass is relatively high, and researchers hope to reduce the hydrogen consumption of coal liquefaction by using hydrogen in biomass, slow down the severity of reaction conditions, and achieve mild liquefaction of coal.

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. Research reports that products formed by pyrolysis of wood flour contribute to hydrogenation reactions of coal liquefaction intermediates (preasphaltene and asphaltene) to form liquid oil; the addition of biomass also facilitates the pyrolytic removal of sulfur and nitrogen from coal and prevents cohesion between particles during coal pyrolysis.

However, since the kerosene slurry has high viscosity, the addition of the biomass particles can further increase the viscosity and cannot be conveyed by a pump, so that the co-liquefaction of the coal and the biomass is limited to the dispersion of the coal dust and the biomass particles in a laboratory by using tetralin with low viscosity as a solvent. We have tried to use water as hydrogen donor solvent to carry out the co-liquefaction process of coal and biomass, but due to the characteristics of biomass, the slurry obtained has fluidity only at very low concentration, i.e. it is not possible to obtain biomass coal water slurry with high concentration and good fluidity at all, which results in that it is impossible to carry out the hydro-liquefaction reaction industrially because it cannot be pumped and is not good for the dispersion of catalyst.

In conclusion, how to improve the liquefaction efficiency of coal liquefaction and further reduce the viscosity of the biomass and coal co-pulping, thereby realizing the mixing of the coal and the biomass and reducing the hydrogen consumption is a technical problem which is not solved by the technical personnel in the field at present.

Disclosure of Invention

The invention firstly solves the technical problem of low liquefaction efficiency caused by limited coal powder content of coal slurry in the prior art, and further overcomes the defect that the prior art does not realize the pulping mixing production technology of coal and biomass on the basis of the problem, thereby providing the multistage liquefaction process of coal and biomass with low hydrogen consumption and high liquefied oil yield.

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

preparing the biomass coal water slurry:

collecting biomass, controlling the water content to be lower than 2 wt%, and then crushing the biomass to the median particle size of 100-300 mu m;

compressing and molding the crushed biomass, wherein the compression pressure is 2-5 MPa;

crushing the compressed and molded biomass again to obtain biomass powder, wherein the median particle size of the crushed biomass powder is 30-50 microns;

collecting coal, controlling the water content to be lower than 2 wt%, and then crushing the coal to obtain particles with a median diameter of 50-100 mu m;

compressing and molding the crushed coal, wherein the compression pressure is 5-15 MPa;

crushing the compressed and molded coal again to obtain coal powder with median particle size of 30-50 μm;

mixing the biomass powder, the coal powder and a catalyst with water, grinding and pulping to obtain biomass coal water slurry, wherein the biomass powder and the coal powder account for 60-70 wt% of the biomass coal water slurry;

first-stage hydrogenation reaction: introducing hydrogen into the biomass coal water slurry to perform a primary hydrogenation reaction, and controlling the reaction pressure to be 15-20 MPa and the reaction temperature to be 220-300 ℃ to obtain a primary hydrogenation product;

and (3) secondary hydrogenation reaction: adding a second catalyst into the primary hydrogenation product, introducing hydrogen to perform a secondary hydrogenation reaction, controlling the reaction pressure to be 15-20 MPa and the reaction temperature to be 380-420 ℃, obtaining a secondary hydrogenation product, and separating the secondary hydrogenation product to finally obtain bio-oil;

in the preparation step of the biomass coal water slurry, when mixing, the biomass powder and the coal powder are firstly subjected to ash removal and are premixed with the catalyst, and then the obtained premix is mixed with the water, or the biomass powder, the coal powder and the catalyst are directly mixed with the water.

In the biomass coal water slurry, the concentration of biomass is 20-30 wt%, and the concentration of coal powder is 30-45 wt%.

And controlling the water content by adopting drying dehydration, wherein the drying dehydration temperature is 50-70 ℃, and the drying dehydration time is 3-5 h.

In the preparation step of the biomass coal water slurry, the bulk density of the biomass powder is controlled to be 300-500 kg/m³Controlling the bulk density of the pulverized coal to be 1200-1300 kg/m³。

The grinding and pulping time is 2-8 min.

The coal is low-rank coal.

In the biomass coal water slurry, the content of the first catalyst is 0.1-10 wt%, preferably 2 wt%; the particle size of the first catalyst is 5-500 mu m;

the adding amount of the second catalyst is 0.5-2 wt% of the mass of the first-stage hydrogenation product, and the particle size of the second catalyst is 5-500 mu m;

before the second catalyst is added into the first-stage hydrogenation product, the method also comprises a step of preparing the second catalyst into a catalyst slurry, and specifically comprises the following steps:

and (2) mixing the second catalyst and water according to the mass ratio of (1-2): 10 to obtain the catalyst slurry.

The specific method for introducing hydrogen in the first-stage hydrogenation reaction step comprises the following steps:

injecting high-pressure hydrogen into the biomass coal water slurry, and controlling the volume ratio of the high-pressure hydrogen to the biomass coal water slurry to be (600-1000): 1, thereby forming a primary reaction feedstock;

feeding the primary reaction raw material into a first slurry bed reactor to perform primary hydrogenation reaction, injecting high-pressure cold hydrogen into the first slurry bed reactor, and controlling the total gas velocity in the first slurry bed reactor to be 0.02-0.2 m/s, preferably 0.05-0.08 m/s;

the pressure of the high-pressure hydrogen and the pressure of the high-pressure cold hydrogen are both 13-27 MPa, and the temperature of the high-pressure cold hydrogen is 50-135 ℃;

the method for introducing hydrogen in the secondary reaction step comprises the following steps:

heating a mixture of the primary hydrogenation product and the second catalyst to 380-480 ℃, preferably 430 ℃, then sending the mixture into a second slurry bed reactor, introducing high-pressure high-temperature hydrogen to perform a secondary hydrogenation reaction, simultaneously injecting high-pressure cold hydrogen into the second slurry bed reactor, controlling the total gas velocity in the second slurry bed reactor to be 0.06-0.1 m/s, and controlling the volume ratio of the hydrogen to the primary hydrogenation product to be (1000-1500): 1;

the pressure of the high-pressure high-temperature hydrogen and the pressure of the high-pressure cold hydrogen are both 13-27 MPa, the temperature of the high-pressure high-temperature hydrogen is 430-480 ℃, and the temperature of the high-pressure cold hydrogen is 50-135 ℃.

Injecting the high-pressure hydrogen into the biomass coal water slurry twice, specifically comprising the following steps:

after high-pressure medium-temperature hydrogen is injected into the biomass coal water slurry for the first time, the biomass coal water slurry is subjected to heat exchange and is heated to 200-350 ℃, and then high-pressure high-temperature hydrogen is injected into the biomass coal water slurry for the second time;

the temperature of the high-pressure medium-temperature hydrogen is 180-350 ℃, and the temperature of the high-pressure high-temperature hydrogen injected for the second time is 360-510 ℃.

The inventory of the first catalyst in the first slurry bed reactor is controlled to be 5-30 wt% of the mass of the liquid phase in the first slurry bed reactor, and the inventory of the second catalyst in the second slurry bed reactor is controlled to be 5-30 wt% of the mass of the liquid phase in the second slurry bed reactor.

The time of the first-stage hydrogenation reaction is 30-60 min, and the time of the second-stage hydrogenation reaction is 30-60 min.

And the method also comprises the step of carrying out hydro-reforming on the secondary hydrogenation product under the conditions that the pressure is 7-23 MPa and the temperature is 250-460 ℃.

The first catalyst is biomass charcoal which is subjected to vulcanization treatment and loaded with a first active component, and the first active component is one or more of ferric oxide, ferric oxyhydroxide or ferric hydroxide; the second catalyst is biomass charcoal which is subjected to vulcanization treatment and loaded with a second active component, and the second active component is one or more of oxides of Mo, W, Fe, Co, Ni or Pd;

or the first catalyst is amorphous iron oxyhydroxide which is subjected to vulcanization treatment, the second catalyst is amorphous alumina which is subjected to vulcanization treatment and loaded with a third active component, and the third active component is selected from one or more oxides of metals in VIB, VIIB or VIII groups of the periodic table of elements.

The biomass raw material in the invention can be solid straws of crops such as wheat, rice, corn, cotton and the like, can also be commercial crops such as reed, common sage herb, trees, leaves, fruits and vegetables and the like, and can also be algae, industrial wood, paper waste and the like; liquid feces and the like; can be a biomass or a biomass raw material composed of a plurality of biomasses.

The preparation method of the biomass charcoal loaded with the first active component comprises the following steps:

(1) selecting biomass charcoal as a first biomass charcoal carrier;

(2) and (3) loading a first active component on the first biomass carbon carrier to prepare the first catalyst.

The specific method for loading the first active component on the first biomass carbon carrier comprises the following steps:

mixing the first biomass carbon carrier and the first active component aqueous solution to prepare a suspension, adding a precipitator to precipitate the first active component on the first biomass carbon carrier, and washing and drying to prepare the first catalyst; wherein the precipitant is ammonia water or at least one aqueous solution of carbonate, bicarbonate and hydroxide of alkali metal, the temperature in the precipitation process is controlled to be 30-90 ℃, and the pH value is 7-9.

The preparation method of the biomass charcoal loaded with the second active component comprises the following steps:

(1) acidifying or alkalizing the biomass charcoal to prepare a second biomass charcoal carrier;

(2) and mixing and grinding a second active component and the second biomass charcoal carrier to prepare a second catalyst.

The step of mixing and grinding the second active component and the second biomass charcoal carrier comprises the following steps: and carrying out vibration grinding and/or plane grinding and/or ball milling on the second active component and the second biomass carbon carrier to obtain a second catalyst with the particle size of 5-500 microns.

H in the acidified acidic medium⁺The mass concentration of the substance(s) is 0.5mol/L to 5 mol/L; the volume ratio of the biomass charcoal to the acidic medium is 1: 5-1: 15, the acidification temperature is 30-80 ℃, and the acid is usedThe chemical time is 1-10 h; OH in the alkalinized alkaline medium^-The mass concentration of the substance(s) is 0.5mol/L to 5 mol/L; the volume ratio of the biomass charcoal to the alkaline medium is 1: 5-1: 15, the alkalization temperature is 30-80 ℃, and the alkalization time is 1-10 h.

The technical scheme of the invention has the following advantages:

1. the invention creatively realizes the mixing liquefaction of the coal and the biomass by taking water as a hydrogen supply solvent for the first time, and provides a multistage liquefaction process of the coal and the biomass. According to the invention, biomass and coal water slurry with biomass and coal content of 55-65 wt% and viscosity of 450-1100 mPa & s (50 ℃) is successfully prepared by the process flow of biomass and coal dehydration, crushing, compression, re-crushing, primary pulping and grinding pulping, and optimization of crushed particle size and compression conditions.

The compression treatment can collapse and close the pore structures in the coal and biomass materials, and plastic rheology and plastic deformation occur, so that the density of the coal and biomass raw materials is greatly improved, and the coal and biomass raw materials can be well dispersed in water; meanwhile, the collapse and the closure of the pore structure avoid the adsorption of coal and biomass on water, so that the water can fully play the role of the water as a dispersing agent; we have found that the compression temperature has a great influence on the degree of plastic rheology and plastic deformation, the higher the temperature is, the higher the density is, however, the higher the temperature is, the material decomposition or other problems may be caused, so 30-60 ℃ is adopted as the compression temperature. The operation of smashing once more after the compression has increased the contactable area of raw materials for raw materials can better contact with catalyst and water, can strengthen the transmission of hydrogen, thereby the condition that the raw materials can't contact with hydrogen and catalyst and react because of being in pore form structure is greatly reduced.

The invention provides the method of 'crushing, compressing and re-crushing' which is suitable for all coal materials and biomass materials with internal pore structures, in particular low-rank coal raw materials such as brown coal and the like, and porous and loose biomass raw materials such as straws and rice hulls; the prepared high-concentration biomass coal water slurry has good slurrying property and high fluidity, can be directly and stably conveyed by a pump, not only can effectively improve the operation stability of a conveying system, the utilization efficiency of a liquefying device and the liquefying efficiency, meet the feeding requirement of a subsequent treatment process, but also realizes the clean and efficient utilization of inferior coal and biomass; the close proximity of coal and biomass allows hydrogen produced by biomass pyrolysis to be used as part of the hydrogen source for coal pyrolysis hydrogenation, reducing hydrogen consumption.

According to the coal and biomass multistage liquefaction process provided by the invention, coal and biomass are hydrolyzed at high pressure and high temperature, and primary cracking, hydrogenation reaction, deep cracking and hydrogenation reaction are sequentially carried out on a hydrolysate under the action of hydrogen and a first catalyst and a second catalyst, so that the conversion from coal and biomass to bio-oil and the refining of bio-oil are realized. In the process, the conversion rate of the biomass and the coal can reach 97-99%, the yield of the bio-oil can reach 70-80%, and the residue amount is less than 3%.

2. The multi-stage liquefaction process of the coal and the biomass provided by the invention is further matched with a solid material screening process, so that the uniform particle size of solid particles for preparing the biomass coal water slurry can be ensured, the obtained biomass coal water slurry has better stability, the biomass coal water slurry is not easy to settle in the transportation process, and the blockage of a transportation pipeline and the damage to liquefaction equipment are avoided. The solid biomass is pretreated by drying, crushing, ash removal and the like, and then is mixed with the catalyst, so that the surface energy of the coal and biomass powder is better utilized to enable the catalyst to be attached to the surface of the coal and biomass powder, and the catalyst can timely provide hydrogen transfer for the coal and biomass hydrolysate, thereby ensuring that coke polycondensation cannot be generated in the whole process and achieving the purpose of reducing the residue.

Amorphous alumina loaded with VIB, VIIB or VIII group metal oxides is used as a second catalyst, hydrogen is introduced, the bio-oil is refined, better hydrogenation performance obtained after noble metal vulcanization can be utilized, coke formation is further avoided, and the amorphous alumina has acidity, so that cracking is more sufficient.

3. The invention provides a multi-stage liquefaction process of coal and biomass, which adopts at least two slurry bed reactors, firstly, reaction raw materials are sequentially sent into the reactors to carry out hydrogenation reaction, and cold hydrogen is injected into the reactors, so that the difference control of phase flow velocity can be realized in the two reactors by depending on different specific gravities of gas, liquid and solid materials and matching with the change of specific gravity difference caused by the yield of biological oil products after reaction, the coal and biomass raw materials are hydrolyzed, cracked and hydrogenated in the reactors from bottom to top, even if the coal, biomass and catalyst solid particles with larger specific gravity rise along with the gas and water in the process, the coal, biomass and catalyst solid particles return to the bottom to participate in the reaction again under the action of the cold hydrogen at the upper part, the hydrogen content and the cold hydrogen injection amount in the biomass coal-water slurry entering the reactors are properly adjusted according to the material densities at the upper part, the middle part and the lower part of the reactors, thereby realizing the circulation of unconverted coal and biomass in the reactor and the balanced discharge of the catalyst, ensuring the full reaction of hydrolysis, cracking, hydrogenation and the like, and being beneficial to improving the conversion rate of the coal and the biomass and the yield of the bio-oil.

4. According to the multi-stage liquefaction process of the coal and the biomass, high-pressure hydrogen is injected into the biomass coal water slurry for three times, namely, the high-pressure hydrogen is injected once before and after the biomass coal water slurry is heated, and then the high-pressure hydrogen is injected once again before a mixture of the first-stage hydrogenation product and the second catalyst enters the second slurry bed reactor, so that disturbance of the biomass coal water slurry in the heat exchanger can be increased through the injection of the first-stage high-pressure hydrogen, and deposition of the coal, the biomass and the catalyst is avoided. High-pressure hydrogen is injected for three times, so that the gas velocity can be supplied to various liquids, solids and catalysts, the difference of rising and staying in the reactor can be realized by depending on the phase state and density difference of a mixture, and meanwhile, the gas quantity can be supplemented and adjusted through a hydrogen injection port on the outer wall of the reactor according to the density difference between layers in the reactor, so that the full progress of hydrolysis, cracking and hydrogenation reactions is ensured.

Detailed Description

The technical solutions of the present invention will be described clearly and completely below, and it should be apparent that the described embodiments are some, but not all, embodiments of the present invention. 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. 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.

The calculation formulas for the conversion of coal to biomass, bio-oil yield, and residue content described in the following examples and comparative examples are as follows:

conversion of coal to biomass (quality of secondary hydrogenation product-quality of catalyst-quality of water)/(quality of coal to biomass sum)

Bio-oil yield (bio-oil mass/(coal and biomass mass sum)

Residue content ═ residue mass/(sum of mass of coal and biomass)

Example 1

A coal and biomass multi-stage liquefaction process comprises the following steps:

(1) taking lignite, drying and dehydrating the lignite, crushing the lignite to the median particle size of 100 microns, and then sending the lignite into a briquetting machine for extrusion forming at the forming pressure of 15MPa to obtain the lignite compressed material. And (3) feeding the lignite compressed material into a hammer crusher for crushing to obtain pulverized lignite with the particle size of 100 mu m. Adding the pulverized brown coal and amorphous iron oxyhydroxide which is subjected to vulcanization treatment in a reactor into a mixture of excrement and water together to form biomass coal water slurry, and introducing hydrogen into the biomass coal water slurry to perform primary hydrogenation reaction to obtain a primary hydrogenation product.

(2) Adding amorphous alumina which is vulcanized in a reactor and loaded with Mo oxide and Ni oxide into the primary hydrogenation product, and introducing hydrogen to perform secondary hydrogenation reaction to obtain a secondary hydrogenation product, wherein the secondary hydrogenation product is separated to finally obtain bio-oil; wherein the pressure of the two reactions is controlled to be 16MPa, the temperature of the first-stage hydrogenation reaction is 300 ℃, the reaction time is 50min, the temperature of the second-stage hydrogenation reaction is 380 ℃, and the reaction time is 45 min.

Example 2

pretreatment of straws:

taking wheat straws and corn straws, drying and dehydrating the wheat straws and the corn straws, crushing the wheat straws and the corn straws into particles with a median diameter of 100 mu m, and then sending the particles into a plodder to carry out extrusion forming under the forming pressure of 2MPa to obtain a straw compression material;

and (3) feeding the straw compressed material into a hammer piece crusher, crushing to obtain straw crushed material with the median particle size of 50 mu m for later use.

Pretreating a coal raw material:

taking lignite, drying and dehydrating the lignite, crushing the lignite to 50 microns of median particle size, and then sending the lignite into a briquetting machine for extrusion forming at the forming pressure of 5MPa to obtain a lignite compressed material;

and (3) feeding the lignite compressed material into a ball mill, and crushing to obtain pulverized lignite with the median particle size of 30 mu m for later use.

Preparation and hydrogenation reaction of biomass coal water slurry:

removing ash from the straw crushed materials and the brown coal crushed materials, mixing the straw crushed materials and the brown coal crushed materials with the biomass carbon loaded with iron oxide after vulcanization treatment to obtain a mixture, and adding the mixture into water to form biomass coal water slurry; in the biomass coal water slurry, the content of the straw is 15 wt%, and the content of the lignite is 45 wt%; introducing hydrogen into the biomass coal water slurry to perform a primary hydrogenation reaction to obtain a primary hydrogenation product; and then adding the biomass carbon which is subjected to vulcanization treatment and loaded with W oxide and Ni oxide into the primary hydrogenation product, and introducing hydrogen to perform secondary hydrogenation reaction to obtain a secondary hydrogenation product, wherein the secondary hydrogenation product is separated to finally obtain the bio-oil.

Wherein the pressure of the two reactions is controlled to be 15MPa, the temperature of the first-stage hydrogenation reaction is 270 ℃, the reaction time is 35min, the temperature of the second-stage hydrogenation reaction is 380 ℃, and the reaction time is 60 min.

In this example, the iron oxide-loaded biomass char (first catalyst) was prepared by the following method:

(1) selecting biomass charcoal as a first biomass charcoal carrier;

(2) and mixing the first biomass carbon carrier and the vulcanized iron oxide aqueous solution to prepare a suspension, adding a precipitator to precipitate the vulcanized iron oxide on the first biomass carbon carrier, and washing and drying to obtain the first catalyst. Wherein, the precipitant is ammonia water and sodium carbonate solution, the temperature is controlled at 30 ℃ in the precipitation process, and the pH value is 7.

The content of the iron oxide is 10 wt% based on the total mass of the iron oxide and the biomass charcoal;

the biomass charcoal (second catalyst) loaded with W oxide and Ni oxide was prepared by the following method:

(1) acidifying the biomass carbon to prepare a second biomass carbon carrier;

h in the acidified acidic medium⁺The amount concentration of the substance(s) is 0.5 mol/L; the volume ratio of the biomass charcoal to the acidic medium is 1:5, the acidification temperature is 30 ℃, and the acidification time is 1 h.

(2) And ball-milling the W oxide, the Ni oxide and the second biomass charcoal carrier to obtain a second catalyst with the particle size of 500 mu m.

The content of W oxide and Ni oxide was 1 wt% based on the total mass of W oxide and Ni oxide and biomass charcoal.

Example 3

pretreatment of the biomass raw material:

(1) drying and dehydrating reed, and pulverizing with jet mill to obtain crushed material with particle diameter D₅₀And 200 μm.

(2) And (3) feeding the crushed material of the reed into a briquetting machine or a plodder for extrusion forming, wherein the forming pressure is 3MPa, so as to obtain the compressed material of the reed.

(3) Feeding the compressed reed material into a jet mill for secondary crushing to obtain secondary crushed reed material with a particle size D₅₀Is 40 μm for standby.

Pretreating a coal raw material:

(1) drying and dehydrating the Shendong long flame coal, and then feeding the dried and dehydrated Shendong long flame coal into a ball mill for crushing to obtain the Shendong long flame coal primary crushed material with the particle size D₅₀Is 100 μm.

(2) And (3) sending the crushed material of the Shendong long flame coal into a briquetting machine or a plodder for extrusion forming, wherein the forming pressure is 12MPa, so as to obtain the Shendong long flame coal compression material.

(3) Feeding the Shendong long flame coal compressed material into a ball mill for secondary crushing to obtain a Shendong long flame coal secondary crushed material with a particle size D₅₀80 μm for use.

Preparation and hydrogenation reaction of biomass coal water slurry:

after ash removal, the secondarily crushed materials of the reed and the coal are mixed with biomass charcoal loaded with hydroxyl iron oxide after vulcanization treatment in a reactor to obtain a mixture, and the mixture is added into water, so that the biomass coal water slurry is formed; the biomass coal water slurry is continuously processed by the colloid mill, so that the slurrying property of the biomass coal water slurry can be continuously improved.

Introducing hydrogen into the biomass coal water slurry to perform a primary hydrogenation reaction to obtain a primary hydrogenation product; adding biomass carbon which is vulcanized in a reactor and loaded with Pd oxide and Ni oxide into the primary hydrogenation product, and introducing hydrogen to perform secondary hydrogenation reaction to obtain a secondary hydrogenation product, wherein the secondary hydrogenation product is separated to finally obtain the bio-oil.

Wherein, the pressure of the two reactions is controlled to be 17MPa, the temperature of the first-stage hydrogenation reaction is 260 ℃, the reaction time is 45min, the temperature of the second-stage hydrogenation reaction is 390 ℃, and the reaction time is 60 min. In the biomass coal water slurry, the content of the reed is 30 wt%, the content of the coal is 35 wt%, the content of the first catalyst is 0.1 wt%, and the particle size of the first catalyst is 500 mu m; the adding amount of the second catalyst is 0.5 wt% of the mass of the first-stage hydrogenation product, and the particle size of the second catalyst is 500 mu m; before the second catalyst is added into the first-stage hydrogenation product, the method also comprises a step of preparing the second catalyst into a catalyst slurry, which comprises the following specific steps: and (2) mixing the second catalyst and water according to a mass ratio of 1: 10 to obtain the catalyst slurry.

Example 4

pretreatment of the biomass raw material:

(1) taking leaves and melons and fruits, drying and dehydrating the leaves and melons and fruits, and then feeding the dried leaves and melons and fruits into a jet mill for crushing treatment to obtain crushed materials with the particle size D₅₀Was 240 μm.

(2) And (3) conveying the crushed materials of the leaves and the melons and fruits into a briquetting machine or a plodder for extrusion forming, wherein the forming pressure is 2MPa, so as to obtain the compressed materials of the leaves and the melons and fruits.

(3) Feeding the compressed materials into an air flow crusher for secondary crushing to obtain secondary crushed materials with particle size D₅₀Is 30 μm for standby.

Pretreating a coal raw material:

(3) Feeding the Shendong long flame coal compressed material into a ball mill for secondary crushing to obtain a Shendong long flame coal secondary crushed material with a particle size D₅₀Is 30 μm for standby.

Preparation and hydrolysis hydrogenation reaction of biomass coal water slurry:

mixing the ash-removed secondary crushed materials of the leaves and the melons and the fruits with biomass charcoal loaded with ferric hydroxide subjected to vulcanization treatment in a reactor to obtain a mixture, and adding the mixture into water to form the biomass coal water slurry;

introducing hydrogen into the biomass coal water slurry to perform a primary hydrogenation reaction to obtain a primary hydrogenation product; and then adding biomass carbon which is vulcanized in the reactor and loaded with Mo oxide and Co oxide into the primary hydrogenation product, and introducing hydrogen to perform secondary hydrogenation reaction to obtain a secondary hydrogenation product, wherein the secondary hydrogenation product is separated to finally obtain the bio-oil.

Wherein the pressure of the two reactions is controlled to be 18MPa, the temperature of the first-stage hydrogenation reaction is 240 ℃, the reaction time is 50min, the temperature of the second-stage hydrogenation reaction is 380 ℃, and the reaction time is 30 min. In the biomass coal water slurry, the content of the leaves and the melons and fruits is 20 wt%, the content of the coal is 40 wt%, the content of the first catalyst is 2 wt%, and the particle size of the first catalyst is 400 mu m; the adding amount of the second catalyst is 0.8 wt% of the mass of the first-stage hydrogenation product, and the particle size of the second catalyst is 400 mu m; before the second catalyst is added into the first-stage hydrogenation product, the method also comprises a step of preparing the second catalyst into a catalyst slurry, which comprises the following specific steps: and (2) mixing the second catalyst with water according to a mass ratio of 2: 10 to obtain the catalyst slurry.

Example 5

pretreatment of the biomass raw material:

(1) drying and dehydrating algae, and pulverizing with jet mill to obtain primary pulverized material with particle diameter D₅₀Is 150 μm.

(2) And (3) sending the primary crushed algae into a briquetting machine or a plodder for extrusion forming, wherein the forming pressure is 5MPa, so as to obtain the algae compressed material.

(3) Sending the algae compressed material into a jet mill for secondary crushing to obtain secondary crushed material of algae with a particle size D₅₀Is 40 μm for standby.

Pretreating a coal raw material:

(1) taking brown coal, drying and dehydrating the brown coal, and then sending the brown coal into a ball mill for crushing treatment to obtain primary crushed material of the brown coal with a particle size D₅₀Is 50 μm.

(2) And (3) conveying the primary pulverized lignite into a briquetting machine or a plodder for extrusion molding, wherein the molding pressure is 15MPa, so as to obtain the compressed lignite.

(3) Sending the brown coal compressed material into a ball mill for secondary crushing to obtain brown coal secondary crushed material with the particle size D₅₀Is 30 μm for standby.

Screening the secondary crushed material of the algae and the lignite, separating the algae with the particle size larger than 100 mu m from the lignite, and then putting the separated algae and the lignite into a compression link or a secondary crushing link for subsequent feeding and secondary treatment to obtain more uniform particle size so as to obtain more stable biomass coal water slurry.

Preparation and hydrogenation reaction of biomass coal water slurry:

mixing the secondary crushed material of the algae and the lignite after ash removal with the amorphous iron oxyhydroxide which is subjected to vulcanization treatment in the reactor to obtain a mixture, and adding the mixture into water to form the biomass coal water slurry; introducing hydrogen into the biomass coal water slurry to perform a primary hydrogenation reaction to obtain a primary hydrogenation product; and then adding amorphous alumina which is vulcanized in a reactor and loaded with W oxide and Co oxide into the primary hydrogenation product, and introducing hydrogen to perform secondary hydrogenation reaction to obtain a secondary hydrogenation product, wherein the secondary hydrogenation product is separated to finally obtain the bio-oil.

Wherein the pressure of the two reactions is controlled to be 20MPa, the temperature of the first-stage hydrogenation reaction is 220 ℃, the reaction time is 55min, the temperature of the second-stage hydrogenation reaction is 420 ℃, the reaction time is 55min, and the sulfur and the amorphous iron oxyhydroxide are mixed according to the mass ratio of 0.4: 1 mixing and preparing to obtain a first catalyst. In the biomass coal water slurry, the content of algae is 25 wt%, the content of coal is 40 wt%, the content of the first catalyst is 4 wt%, and the particle size of the first catalyst is 300 mu m; the adding amount of the second catalyst is 1.2 wt% of the mass of the first-stage hydrogenation product, and the particle size of the second catalyst is 300 mu m; before the second catalyst is added into the first-stage hydrogenation product, the method also comprises a step of preparing the second catalyst into a catalyst slurry, which comprises the following specific steps: and (2) mixing the second catalyst and water according to a mass ratio of 1: 10 to obtain the catalyst slurry.

The specific method for introducing hydrogen in the first-stage hydrogenation reaction in the embodiment comprises the following steps: injecting high-pressure hydrogen with the pressure of 13MPa into the biomass coal water slurry, and controlling the volume ratio of the high-pressure hydrogen to the biomass coal water slurry to be 600: 1, thereby forming a primary reaction feedstock; and (2) sending the primary reaction raw material into a first slurry bed reactor to perform primary hydrogenation reaction, injecting high-pressure cold hydrogen with the pressure of 13MPa and the temperature of 135 ℃ into the first slurry bed reactor, and controlling the total gas velocity in the first slurry bed reactor to be 0.2 m/s.

The method for introducing hydrogen in the second-stage hydrogenation reaction in the embodiment comprises the following steps: heating the mixture of the primary hydrogenation product and the second catalyst to 380 ℃, then sending the mixture into a second slurry bed reactor, introducing high-pressure high-temperature hydrogen with the pressure of 13MPa and the temperature of 480 ℃ to perform secondary hydrogenation reaction, simultaneously injecting high-pressure cold hydrogen with the pressure of 13MPa and the temperature of 135 ℃ into the second slurry bed reactor, controlling the total gas velocity in the second slurry bed reactor to be 0.1m/s, and controlling the volume ratio of the hydrogen to the primary hydrogenation product to be 1000: 1.

example 6

pretreatment of the biomass raw material:

(1) drying soybean oil residue, dewatering, pulverizing with superfine pulverizer to obtain soybean oil residue material with particle diameter D₅₀And 300 μm.

(2) And (3) feeding the crushed soybean oil residue into a briquetting machine or a plodder for extrusion forming, wherein the forming pressure is 3MPa, so as to obtain the soybean oil residue compressed material.

(3) Feeding the soybean oil residue compressed material into an ultrafine pulverizer, and performing secondary pulverization to obtain a secondary pulverized material of soybean oil residue with a particle size D₅₀50 μm for use.

Pretreating a coal raw material:

(1) taking the long flame coal of Shendong,drying and dehydrating the coal, and then sending the coal into a ball mill for crushing treatment to obtain primary crushed material of Shendong long flame coal with the particle size D₅₀And 80 μm.

(2) And (3) sending the crushed material of the Shendong long flame coal into a briquetting machine or a plodder for extrusion forming, wherein the forming pressure is 10MPa, so as to obtain the Shendong long flame coal compression material.

(3) Feeding the Shendong long flame coal compressed material into a ball mill for secondary crushing to obtain a Shendong long flame coal secondary crushed material with a particle size D₅₀60 μm for use.

Preparation and hydrolysis hydrogenation reaction of biomass coal water slurry:

mixing the secondarily-pulverized material of the soybean oil residue and the Shendong long flame coal after ash removal with amorphous iron oxyhydroxide subjected to vulcanization treatment in a reactor to obtain a mixture, and adding the mixture into waste lubricating oil to form the biomass coal water slurry; introducing hydrogen into the biomass coal water slurry to perform a primary hydrogenation reaction to obtain a primary hydrogenation product; and then adding amorphous alumina which is vulcanized in a reactor and loaded with Mo oxide and Ni oxide into the primary hydrogenation product, and introducing hydrogen to carry out secondary hydrogenation reaction to obtain a secondary hydrogenation product, wherein the secondary hydrogenation product is separated to finally obtain the bio-oil.

Wherein the pressure of the two reactions is controlled to be 20MPa, the temperature of the first-stage hydrogenation reaction is 280 ℃, the temperature of the second-stage hydrogenation reaction is 400 ℃, the time of the first-stage hydrogenation reaction is 30min, the time of the second-stage hydrogenation reaction is 60min, and the sulfur and the amorphous iron oxyhydroxide are mixed according to the mass ratio of 0.8: 1 mixing and preparing to obtain a first catalyst. In the biomass coal water slurry, the content of the soybean oil residue is 30 wt%, the content of the coal is 35 wt%, the content of the first catalyst is 6 wt%, and the particle size of the first catalyst is 200 mu m; the adding amount of the second catalyst is 1.5 wt% of the mass of the first-stage hydrogenation product, and the particle size of the second catalyst is 200 mu m; before the second catalyst is added into the first-stage hydrogenation product, the method also comprises a step of preparing the second catalyst into a catalyst slurry, which comprises the following specific steps: and (2) mixing the second catalyst with water according to a mass ratio of 2: 10 to obtain the catalyst slurry.

The specific method for introducing hydrogen in the first-stage hydrogenation reaction in the embodiment comprises the following steps: after high-pressure medium-temperature hydrogen with the pressure of 18MPa and the temperature of 350 ℃ is injected into the biomass coal water slurry for the first time, the biomass coal water slurry is subjected to heat exchange and is heated to 200 ℃, then high-pressure high-temperature hydrogen with the pressure of 18MPa and the temperature of 510 ℃ is injected into the biomass coal water slurry for the second time, and the volume ratio of the high-pressure hydrogen injected twice to the biomass coal water slurry is controlled to be 700: 1, thereby forming a primary reaction feedstock; and (2) sending the primary reaction raw material into a first slurry bed reactor to perform primary hydrogenation reaction, and injecting high-pressure cold hydrogen with the pressure of 18MPa and the temperature of 100 ℃ into the first slurry bed reactor, wherein the high-pressure cold hydrogen is injected through 5 injection ports on the side wall of the first slurry bed reactor to control the total gas velocity in the first slurry bed reactor to be 0.08 m/s.

The specific method for introducing hydrogen in the secondary hydrogenation reaction in the embodiment comprises the following steps: heating the mixture of the primary hydrogenation product and the second catalyst to 400 ℃, then sending the mixture into a second slurry bed reactor, introducing high-pressure high-temperature hydrogen with the pressure of 18MPa and the temperature of 460 ℃ to perform a secondary hydrogenation reaction, simultaneously injecting high-pressure cold hydrogen with the pressure of 18MPa and the temperature of 100 ℃ into the second slurry bed reactor, injecting the high-pressure cold hydrogen through 5 injection ports on the side wall of the second slurry bed reactor, controlling the total gas velocity in the second slurry bed reactor to be 0.08m/s, and controlling the volume ratio of the hydrogen to the primary hydrogenation product to be 1200: 1.

example 7

treatment of biomass and coal raw materials:

taking rice straws, palm oil residues and lignite, drying and dehydrating the rice straws, the palm oil residues and the lignite, and then sending the rice straws, the palm oil residues and the lignite together into a briquetting machine or a plodder for extrusion molding, wherein the molding pressure is 5MPa, so as to obtain the compressed materials of the rice straws, the palm oil residues and the lignite. And (3) feeding the compressed material into a ball mill, and crushing to obtain crushed materials of rice straws, palm oil residues and lignite for later use.

Preparation and hydrolysis hydrogenation reaction of biomass coal water slurry:

removing ash from the crushed materials, mixing the crushed materials with amorphous iron oxyhydroxide subjected to vulcanization treatment in a reactor to obtain a mixture, adding the mixture into the mixed coal tar and petroleum to form the biomass coal water slurry, and introducing hydrogen into the biomass coal water slurry to perform a primary hydrogenation reaction to obtain a primary hydrogenation product; adding amorphous alumina which is vulcanized in a reactor and loaded with W oxide and Ni oxide into the primary hydrogenation product, and introducing hydrogen to perform secondary hydrogenation reaction to obtain a secondary hydrogenation product, wherein the secondary hydrogenation product is separated to finally obtain bio-oil; further comprising the step of hydro-reforming the secondary hydrogenation product at a pressure of 7MPa and a temperature of 460 ℃.

Wherein, the pressure of the two reactions is controlled to be 19MPa, the temperature of the first-stage hydrogenation reaction is 290 ℃, the temperature of the second-stage hydrogenation reaction is 410 ℃, the time of the first-stage hydrogenation reaction is 40min, the time of the second-stage hydrogenation reaction is 35min, and the sulfur and the amorphous iron oxyhydroxide are mixed according to the mass ratio of 0.6: 1 mixing and preparing to obtain a first catalyst. In the biomass coal-water slurry, the content of palm oil residue is 5 wt%, the content of rice straw is 15 wt%, the content of coal is 40 wt%, the content of a first catalyst is 8 wt%, and the particle size of the first catalyst is 100 μm; the adding amount of the second catalyst is 1.8 wt% of the mass of the first-stage hydrogenation product, and the particle size of the second catalyst is 100 mu m; before the second catalyst is added into the first-stage hydrogenation product, the method also comprises a step of preparing the second catalyst into a catalyst slurry, which comprises the following specific steps: and (2) mixing the second catalyst and water according to a mass ratio of 1: 10 to obtain the catalyst slurry.

The specific method for introducing hydrogen in the first-stage hydrogenation reaction in the embodiment comprises the following steps: after high-pressure medium-temperature hydrogen with the pressure of 23MPa and the temperature of 260 ℃ is injected into the biomass coal water slurry for the first time, the biomass coal water slurry is subjected to heat exchange and is heated to 280 ℃, then high-pressure high-temperature hydrogen with the pressure of 23MPa and the temperature of 430 ℃ is injected into the biomass coal water slurry for the second time, and the volume ratio of the high-pressure hydrogen injected twice to the biomass coal water slurry is controlled to be 800: 1, thereby forming a primary reaction feedstock; will the one-level reaction raw materials send into first thick liquid attitude bed reactor in order to take place one-level hydrogenation, simultaneously to inject pressure into in the first thick liquid attitude bed reactor and be 23MPa, the temperature is the cold hydrogen of 80 ℃ high pressure, the cold hydrogen of high pressure via 4 filling openings on the first thick liquid attitude bed reactor lateral wall are injected, control total gas velocity in the first thick liquid attitude bed reactor is 0.05 m/s.

The method for introducing hydrogen in the secondary hydrogenation reaction in the embodiment comprises the following steps: heating the mixture of the primary hydrogenation product and the second catalyst to 440 ℃, then sending the mixture into a second slurry bed reactor, introducing high-pressure and high-temperature hydrogen with the pressure of 23MPa and the temperature of 440 ℃ to perform secondary hydrogenation reaction, simultaneously injecting high-pressure cold hydrogen with the pressure of 23MPa and the temperature of 80 ℃ into the second slurry bed reactor, injecting the high-pressure cold hydrogen through 4 injection ports on the side wall of the second slurry bed reactor, controlling the total gas velocity in the second slurry bed reactor to be 0.07m/s, and controlling the volume ratio of the hydrogen to the primary hydrogenation product to be 1350: 1. the inventory of the first catalyst in the first slurry bed reactor is controlled to be 5 wt% of the mass of the liquid phase in the first slurry bed reactor, and the inventory of the second catalyst in the second slurry bed reactor is controlled to be 30 wt% of the mass of the liquid phase in the second slurry bed reactor.

Example 8

pretreatment of the biomass raw material:

(1) drying and dehydrating reed, and pulverizing with jet mill to obtain crushed material with particle diameter D₅₀And 300 μm.

(3) Feeding the compressed reed material into a jet mill for secondary crushing to obtain secondary crushed reed material with a particle size D₅₀50 μm for use.

Pretreating a coal raw material:

(1) taking brown coal, drying and dehydrating the brown coal, and then sending the brown coal into a ball mill for crushing treatment to obtain primary crushed material of the brown coal with a particle size D₅₀Is 100 μm.

(2) And (3) conveying the primary pulverized lignite into a briquetting machine or a plodder for extrusion molding, wherein the molding pressure is 12MPa, so as to obtain the compressed lignite.

(3) Sending the brown coal compressed material into a ball mill for secondary crushing to obtain brown coal secondary crushed material with the particle size D₅₀100 μm for use.

The preparation and hydrolysis hydrogenation process of the biomass coal water slurry comprises the following steps:

mixing the secondary crushed material of the reed and the lignite with the amorphous iron oxyhydroxide which is subjected to vulcanization treatment in the reactor to obtain a mixture, and adding the mixture into water to form the biomass coal water slurry; introducing hydrogen into the biomass coal water slurry to perform a primary hydrogenation reaction to obtain a primary hydrogenation product; adding amorphous alumina which is vulcanized in a reactor and loaded with Pd oxide and Co oxide into the primary hydrogenation product, and introducing hydrogen to perform secondary hydrogenation reaction to obtain a secondary hydrogenation product, wherein the secondary hydrogenation product is separated to finally obtain bio-oil; the method also comprises a step of carrying out hydro-reforming on the secondary hydrogenation product under the conditions that the pressure is 23MPa and the temperature is 250 ℃.

Controlling the pressure of the two reactions to be 20MPa, the temperature of the first-stage hydrogenation reaction to be 280 ℃, the temperature of the second-stage hydrogenation reaction to be 400 ℃, the time of the first-stage hydrogenation reaction to be 60min, the time of the second-stage hydrogenation reaction to be 30min, and mixing sulfur and amorphous iron oxyhydroxide in a mass ratio of 1:1 mixing and preparing to obtain a first catalyst. In the biomass coal water slurry, the content of the first catalyst is 10 wt%, and the particle size of the first catalyst is 5 μm; the adding amount of the second catalyst is 2 wt% of the mass of the first-stage hydrogenation product, and the particle size of the second catalyst is 5 mu m; before the second catalyst is added into the first-stage hydrogenation product, the method also comprises a step of preparing the second catalyst into a catalyst slurry, which comprises the following specific steps: and (2) mixing the second catalyst with water according to a mass ratio of 2: 10 to obtain the catalyst slurry.

The specific method for introducing hydrogen in the first-stage hydrogenation reaction in the embodiment comprises the following steps: after high-pressure medium-temperature hydrogen with the pressure of 27MPa and the temperature of 180 ℃ is injected into the biomass coal water slurry for the first time, the biomass coal water slurry is subjected to heat exchange and is heated to 350 ℃, then high-pressure high-temperature hydrogen with the pressure of 27MPa and the temperature of 360 ℃ is injected into the biomass coal water slurry for the second time, and the volume ratio of the high-pressure hydrogen injected twice to the biomass coal water slurry is controlled to be 1000: 1, thereby forming a primary reaction feedstock; will the one-level reaction raw materials send into first thick liquid attitude bed reactor in order to take place one-level hydrogenation, simultaneously to inject pressure into in the first thick liquid attitude bed reactor and be 27MPa, the temperature is the cold hydrogen of high pressure of 50 ℃, the cold hydrogen of high pressure via 3 injection ports on the first thick liquid attitude bed reactor lateral wall are injected, control total gas velocity in the first thick liquid attitude bed reactor is 0.02 m/s.

The specific method for introducing hydrogen in the secondary hydrogenation reaction in the embodiment comprises the following steps: heating the mixture of the primary hydrogenation product and the second catalyst to 480 ℃, then sending the mixture into a second slurry bed reactor, introducing high-pressure high-temperature hydrogen with the pressure of 27MPa and the temperature of 430 ℃ to perform secondary hydrogenation reaction, simultaneously injecting high-pressure cold hydrogen with the pressure of 27MPa and the temperature of 50 ℃ into the second slurry bed reactor, injecting the high-pressure cold hydrogen through 3 injection ports on the side wall of the second slurry bed reactor, controlling the total gas velocity in the second slurry bed reactor to be 0.06m/s, and controlling the volume ratio of the hydrogen to the primary hydrogenation product to be 1500: 1. the inventory of the first catalyst in the first slurry bed reactor is controlled to be 30 wt% of the mass of the liquid phase in the first slurry bed reactor, and the inventory of the second catalyst in the second slurry bed reactor is controlled to be 5 wt% of the mass of the liquid phase in the second slurry bed reactor.

Comparative example 1

A process for liquefaction of biomass comprising the steps of:

taking lignite, drying and dehydrating the lignite, and then sending the lignite into a briquetting machine or a plodder for extrusion forming at the forming pressure of 15MPa to obtain the lignite compressed material. And (3) feeding the lignite compressed material into a hammer crusher for crushing to obtain pulverized lignite with the particle size of 100 mu m. Adding the pulverized brown coal and amorphous iron oxyhydroxide which is subjected to vulcanization treatment in a reactor into a mixture of excrement and water to form biomass coal water slurry, introducing hydrogen into the biomass coal water slurry to perform reaction, and controlling the reaction pressure to be 4MPa and the reaction temperature to be 430 ℃ to finally prepare the bio-oil.

Comparative example 2

A process for liquefaction of biomass comprising the steps of:

taking lignite, drying and dehydrating the lignite, and then sending the lignite into a briquetting machine for extrusion forming at the forming pressure of 20MPa to obtain the lignite compressed material. And (3) feeding the lignite compressed material into a hammer crusher for crushing to obtain pulverized lignite with the particle size of 100 mu m. Adding the pulverized lignite and an oil-soluble dispersed hydrogenation catalyst which is subjected to vulcanization treatment in a reactor into a mixture of liquid excrement and waste engine oil to form biomass coal water slurry, introducing hydrogen into the biomass coal water slurry to perform reaction, and controlling the reaction pressure to be 13MPa and the reaction temperature to be 480 ℃ to finally prepare the biological oil.

The processes using examples of the present invention and comparative examples were compared as shown in table 1 below.

TABLE 1 comparison of the Process effects of the examples and comparative examples

As can be seen from Table 1, compared with comparative examples 1-2, the biomass and coal conversion rate and the bio-oil yield obtained by the process of the present invention are high, while the amount of the residue is significantly reduced, and almost no coke formation is generated, so that the process of the present invention can significantly improve the coal and biomass conversion rate and the bio-oil yield, and reduce the amount of the residue. In addition, the multistage liquefaction enables the hydrogenation reaction to be more sufficient, and the quality of the bio-oil is higher.

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 coal and biomass multi-stage liquefaction process is characterized by comprising the following steps:

preparing the biomass coal water slurry:

crushing the compressed and molded coal again to obtain coal powder with median particle size of 30-100 microns;

mixing the biomass powder, the coal powder, a first catalyst and water, grinding and pulping to obtain biomass coal water slurry, wherein the biomass powder and the coal powder account for 55-65 wt% of the biomass coal water slurry;

in the preparation step of the biomass coal water slurry, when mixing, firstly, ash removal is carried out on the biomass powder and the coal powder, and the biomass powder and the coal powder are premixed with the first catalyst, and then the obtained premix is mixed with the water, or the biomass powder, the coal powder, the first catalyst and the water are directly mixed;

in the biomass coal water slurry, the concentration of biomass is 15-30 wt%, and the concentration of coal powder is 35-50 wt%;

2. The multi-stage coal and biomass liquefaction process according to claim 1, wherein the moisture content is controlled by drying and dehydrating at 50-70 ℃ for 3-5 hours.

3. The coal and biomass multistage liquefaction process according to claim 1 or 2, characterized in that the time for the grinding and pulping is 2-8 min.

4. The multi-stage coal and biomass liquefaction process according to claim 1, characterized in that said coal is low-rank coal.

5. The multi-stage coal and biomass liquefaction process according to claim 1, wherein the content of the first catalyst in the biomass coal-water slurry is 0.1-10 wt%; the particle size of the first catalyst is 5-500 mu m;

6. The multi-stage coal and biomass liquefaction process of claim 5, characterized in that the first catalyst content in the biomass coal-water slurry is 2 wt%.

7. The multi-stage coal and biomass liquefaction process according to claim 1, wherein the specific method for introducing hydrogen in the first-stage hydrogenation reaction step is as follows:

feeding the primary reaction raw material into a first slurry bed reactor to perform primary hydrogenation reaction, and injecting high-pressure cold hydrogen into the first slurry bed reactor at the same time, wherein the total gas velocity in the first slurry bed reactor is controlled to be 0.02-0.2 m/s;

heating a mixture of the primary hydrogenation product and the second catalyst to 380-480 ℃, then sending the mixture into a second slurry bed reactor, introducing high-pressure high-temperature hydrogen to perform a secondary hydrogenation reaction, simultaneously injecting high-pressure cold hydrogen into the second slurry bed reactor, controlling the total gas velocity in the second slurry bed reactor to be 0.06-0.1 m/s, and controlling the volume ratio of the hydrogen to the primary hydrogenation product to be (1000-1500): 1;

8. The coal and biomass multistage liquefaction process according to claim 7, wherein in the specific method of introducing hydrogen in the first stage hydrogenation step, the total gas velocity in the first slurry bed reactor is controlled to be 0.05-0.08 m/s;

in the method for introducing hydrogen in the secondary reaction step, the mixture of the primary hydrogenation product and the second catalyst is heated to 430 ℃.

9. The multi-stage coal and biomass liquefaction process of claim 7, wherein the high pressure hydrogen is injected into the biomass coal-water slurry in two portions, specifically:

10. The coal and biomass multistage liquefaction process according to claim 7 or 9, characterized in that the inventory of the first catalyst in the first slurry bed reactor is controlled to be 5-30 wt% of the mass of the liquid phase in the first slurry bed reactor, and the inventory of the second catalyst in the second slurry bed reactor is controlled to be 5-30 wt% of the mass of the liquid phase in the second slurry bed reactor.

11. The multi-stage coal and biomass liquefaction process according to claim 1, wherein the time for the first-stage hydrogenation reaction is 30-60 min, and the time for the second-stage hydrogenation reaction is 30-60 min.

12. The coal and biomass multistage liquefaction process according to claim 1, further comprising the step of hydro-reforming the secondary hydrogenation product under the conditions of a pressure of 7-23 MPa and a temperature of 250-460 ℃.

13. The multi-stage coal and biomass liquefaction process according to claim 1, wherein the first catalyst is sulfided biomass char loaded with a first active component, the first active component being one or more of iron oxide, iron oxyhydroxide, or iron hydroxide; the second catalyst is biomass charcoal which is subjected to vulcanization treatment and loaded with a second active component, and the second active component is one or more of oxides of Mo, W, Fe, Co, Ni or Pd;