CN108192652B

CN108192652B - Coal and biomass co-liquefaction process

Info

Publication number: CN108192652B
Application number: CN201711431460.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: 2017-12-26
Filing date: 2017-12-26
Publication date: 2020-03-17
Anticipated expiration: 2037-12-26
Also published as: CN108192652A

Abstract

The invention relates to the technical field of clean energy, in particular to a co-refining process of coal and biomass. According to the coal and biomass co-liquefaction process provided by the invention, the coal and biomass raw materials are firstly subjected to crushing, compression and re-crushing, and then slurry is prepared, so that biomass kerosene slurry which is high in solid content and can be stably conveyed by a pump is successfully obtained, and high-viscosity waste oil which cannot be used as a coal and biomass liquefaction solvent in the prior art can also be utilized. Introducing hydrogen into the biomass kerosene slurry, and controlling the reaction pressure to be 15-25 MPa and the reaction temperature to be 380-480 ℃, so as to finally prepare the bio-oil; the process of the invention leads coal and biomass to be liquefied under high pressure and high temperature environment and further to carry out cracking and hydrogenation reaction, thereby realizing the conversion from the coal and the biomass to the bio-oil. In the process, the conversion rate of coal and biomass can reach 90-95%, the yield of bio-oil can reach 40-75%, and the residue amount is not higher than 3%.

Description

Coal and biomass co-liquefaction process

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. The kerosene refining technology is a technology developed recently for jointly processing coal and heavy oil, overcomes the harsh condition of direct coal liquefaction, and can also utilize the heavy oil at the same time, so that the technology becomes a research hotspot for clean utilization of coal. For example, chinese patent document CN105647578 discloses a technology for kerosene mixing and hydrorefining, which comprises preparing coal oil slurry from 50-200 μm coal powder and residual oil, adding hydrogen, catalyst and vulcanizing agent, feeding into slurry bed, and performing cracking hydrogenation reaction under 17-25 MPa; separating the obtained hydrogenation product, and then sending to hydrofining to obtain light hydrocarbon, naphtha, diesel oil and wax oil.

However, this technique has two problems in common with most kerosene mixing processes of the prior art: low liquefaction efficiency and large hydrogen consumption.

1. Low efficiency of liquefaction

The kerosene slurry prepared from coal powder and oil needs 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 content of the coal powder in the kerosene slurry in the kerosene co-refining technology cannot be too high, 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 cracked to generate asphaltene and asphaltene, and gas, liquefied oil and macromolecular polycondensate are generated along with the asphaltene and the asphaltene.

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 view of the first problem, in order to improve 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 mineral spirits. 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.

In response to the second problem, researchers have attempted to utilize biomass with coal for pyrolysis hydrogenation in order to reduce hydrogen consumption. 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 is also beneficial to the pyrolysis removal of sulfur and nitrogen in coal and prevents the cohesion between particles in the coal cracking process.

However, since the kerosene slurry has a very high viscosity, and the addition of the biomass particles can further increase the viscosity and cannot be conveyed by a pump, the present co-liquefaction of the coal and the biomass is only limited to the dispersion of the coal dust and the biomass particles in a laboratory by using tetralin with a lower viscosity as a solvent, that is, the present technology does not really realize the mixing production of the coal, the biomass and the oil.

In conclusion, how to increase the content of coal dust in the kerosene slurry, improve the liquefaction efficiency, and further reduce the viscosity of the kerosene slurry, thereby realizing the mixing liquefaction of coal, biomass and oil 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 aims to solve the technical problem of low liquefaction efficiency caused by limited coal dust content of coal slurry in the prior art and further overcomes the defect that the mixing production technology of coal, biomass and oil is not realized in the prior art on the basis of the problem, thereby providing a coal and biomass co-liquefaction process with low hydrogen consumption and high liquefied oil yield.

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

a co-liquefaction process of coal and biomass comprises the following steps:

preparing biomass kerosene 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, and the compression temperature is 30-60 ℃;

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, and the compression temperature is 30-60 ℃;

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, a catalyst and an oil product in proportion, grinding and pulping to obtain biomass kerosene slurry, wherein the biomass powder and the coal powder account for 60-70 wt% of the biomass kerosene slurry;

and (3) liquefaction reaction: introducing hydrogen into the biomass kerosene slurry to react, controlling the reaction pressure to be 15-25 MPa and the reaction temperature to be 380-480 ℃, and finally preparing the bio-oil;

in the preparation step of the biomass coal oil slurry, when mixing, the biomass powder and the coal powder are firstly deashed and premixed with the catalyst, and then the obtained premix is mixed with the oil product, or the biomass powder, the coal powder and the catalyst are directly mixed with the oil product.

In the biomass kerosene slurry, the concentration of biomass is 20-30 wt%, and the concentration of pulverized coal 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.

The compression molding is briquetting molding, tabletting molding or layering molding.

In the preparation step of the biomass kerosene 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 1000-1200 kg/m³。

The pulverization is hammer mill pulverization, ball milling pulverization, rod mill pulverization, ultramicro pulverization or air current pulverization.

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

The grinding and pulping time is 2-8 min.

The viscosity of the biomass kerosene slurry is 550-1000mPa & s (50 ℃).

The coal is low-rank coal; the oil product is one or more of hogwash oil, waste oil, rancid oil, waste lubricating oil, waste engine oil, heavy oil, residual oil, wash oil, anthracene oil, coal tar, petroleum or biological oil prepared by the process.

In the biomass kerosene slurry, the content of the catalyst is 0.1-10 wt%, preferably 2 wt%; the particle size of the catalyst is 5-500 μm.

The specific method for introducing the hydrogen comprises the following steps:

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

feeding the reaction raw materials into a slurry bed reactor to carry out liquefaction, cracking and hydrogenation reactions, and injecting high-pressure cold hydrogen into the slurry bed reactor at the same time, wherein the total gas velocity in the slurry bed reactor is controlled to be 0.02-0.2 m/s, and 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 ℃.

Injecting the high-pressure hydrogen into the biomass kerosene slurry twice, specifically comprising:

after high-pressure medium-temperature hydrogen is injected into the biomass kerosene slurry for the first time, the biomass kerosene slurry is subjected to heat exchange and is heated to 300-400 ℃, and then high-pressure high-temperature hydrogen is injected into the biomass kerosene slurry for the second time;

the temperature of the high-pressure medium-temperature hydrogen is 300-400 ℃, and the temperature of the high-pressure high-temperature hydrogen is 410-510 ℃.

And injecting the cold hydrogen through 3-5 injection ports on the side wall of the slurry bed reactor.

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

The reaction time is 30-90 min.

The preparation step of the biomass kerosene slurry also comprises the operation of screening the biomass powder and the coal dust, and the solid material with the granularity exceeding the limited granularity is sent back to the compression or the crushing link for operation again; the limited particle size is 80-100 μm.

The catalyst is biomass charcoal which is subjected to vulcanization treatment and loaded with active components, and the active components are one or more of ferric oxide, iron oxyhydroxide or ferric hydroxide;

or the catalyst is amorphous iron oxyhydroxide after vulcanization treatment.

The biomass used in the invention can be solid, such as straws of crops such as wheat, rice, corn, cotton and the like, economic crops such as reed, bamboo grass, trees, leaves, fruits and vegetables and the like, algae, industrial wood, paper waste and the like; the biomass coal oil slurry can also be in a liquid state, such as liquid excrement and the like, and when liquid biomass is adopted, the compression and crushing processes of biomass raw materials are omitted in the step of preparing the biomass coal oil slurry; the biomass can also be a biomass raw material composed of one biomass or a plurality of biomasses.

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

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

(2) and loading an active component on the biomass charcoal carrier to prepare the catalyst.

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

mixing the biomass charcoal carrier and the active component aqueous solution to prepare a suspension, adding a precipitator to precipitate the active component on the biomass charcoal carrier, and washing and drying to prepare the 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.

Or the catalyst is amorphous iron oxyhydroxide after vulcanization treatment.

The technical scheme of the invention has the following advantages:

1. the invention creatively realizes the mixing liquefaction of coal, biomass and oil for the first time and provides a co-liquefaction process of coal and biomass. The biomass coal oil slurry with biomass and coal contents of 60-70 wt% and viscosity of only 550-.

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 the solvent oil; meanwhile, the collapse and the closure of the pore structure avoid the adsorption of the coal and the biomass to the solvent oil, so that the solvent oil can fully play the role of the dispersant; 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 solvent naphtha, can strengthen the transmission of hydrogen, thereby the condition that the raw materials can't contact hydrogen and catalyst and react because of being in pore 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 kerosene slurry has good slurry forming 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. The co-liquefaction process provided by the invention enables high-viscosity waste oil which can not be used as a coal and biomass liquefaction solvent in the prior art, such as waste engine oil, illegal cooking oil, rancid oil and the like, to be utilized.

Introducing hydrogen into the biomass kerosene slurry to react, and controlling the reaction pressure to be 15-25 MPa and the reaction temperature to be 380-480 ℃ to finally prepare the bio-oil; the process of the invention leads coal and biomass to be liquefied under the conditions of high pressure and high temperature, and further to carry out cracking and hydrogenation reaction under the action of hydrogen and catalyst, thereby realizing the conversion from coal and biomass to bio-oil. In the process, the conversion rate of coal and biomass can reach 90-95%, the yield of bio-oil can reach 40-75%, and the residue amount is not higher than 3%.

2. The coal and biomass co-liquefaction process provided by the invention is matched with the process of screening solid materials, so that the uniform particle size of solid particles for preparing biomass coal-oil slurry can be ensured, the stability of the obtained biomass coal-oil slurry is better, the biomass coal-oil 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 liquefied product, thereby ensuring that coke polycondensation cannot be generated in the whole process, and achieving the purpose of reducing the residue amount.

3. The invention provides a coal and biomass co-liquefaction process, which adopts a slurry bed reactor, firstly, reaction raw materials are sent into the slurry bed reactor from the bottom of the reactor to react, and simultaneously, cold hydrogen is injected into the reactor, so that the difference control of the flow velocity of each phase state can be realized in the reactor by depending on the different specific gravities of gas, liquid and solid materials and matching with the change of the specific gravity difference caused by the yield of biological oil products after the reaction, the coal, the biomass and the catalyst solid particles with larger specific gravity are subjected to liquefaction, cracking and hydrogenation reaction from bottom to top in the reactor, even if the coal, the biomass and the catalyst solid particles with larger specific gravity rise along with the gas and the biological oil products in the process, the coal, the biomass and the catalyst solid particles return to the bottom to participate in the reaction again under the action of the cold hydrogen at the upper part of the reactor, the hydrogen content and the cold hydrogen injection amount in the biomass oil slurry entering the reactor are properly adjusted according to, thereby realizing the circulation of unconverted coal and biomass in the reactor and the balanced discharge of the catalyst, ensuring the full progress of the reactions such as liquefaction, 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 co-liquefaction process of the coal and the biomass, the high-pressure hydrogen is injected into the biomass coal oil slurry twice, namely the high-pressure hydrogen is injected once before and after the biomass coal oil slurry is heated, and the disturbance of the biomass coal oil slurry in the heat exchanger can be increased by the previous injection of the high-pressure hydrogen, so that the deposition of the coal, the biomass and the catalyst is avoided.

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 ═ (mass of liquefaction reaction product-mass of catalyst-mass of mineral spirits)/(mass sum of coal and biomass)

Yield of bio-oil (mass sum of coal and biomass) of oil phase obtained by separating liquefied reaction product

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

Example 1

A co-liquefaction process of coal and biomass comprises the following steps:

taking lignite, drying and dehydrating the lignite, crushing the lignite to obtain a powder with a median particle size of 50 microns, and then carrying out extrusion forming at 30 ℃ under a forming pressure of 15MPa to obtain the lignite compressed material. Crushing the lignite compressed material to obtain pulverized lignite with the particle size of 30 mu m. Adding the pulverized lignite and the amorphous iron oxyhydroxide which is subjected to vulcanization treatment in the reactor into a mixture of liquid excrement and waste engine oil to form biomass coal oil slurry, introducing hydrogen into the biomass coal oil slurry to perform reaction, and controlling the reaction pressure to be 16MPa and the reaction temperature to be 480 ℃ to finally prepare the bio-oil.

Example 2

A co-liquefaction process of coal and biomass comprises the following steps:

pretreatment of straws:

(1) taking straws, drying and dehydrating the straws, crushing the straws to 300 mu m in median particle size, and then sending the straws into a briquetting machine or a plodder to carry out extrusion forming at 60 ℃, wherein the forming pressure is 2MPa, so as to obtain the straw compression material.

(2) And feeding the straw compressed material into a hammer piece crusher, and crushing to obtain straw crushed material for later use.

Pretreating a coal raw material:

(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 temperature of 30 ℃, wherein the forming pressure is 5MPa, so as to obtain the lignite compressed material.

(2) And (3) feeding the lignite compressed material into a ball mill, and crushing to obtain pulverized lignite with the median particle size of 50 microns for later use.

Preparation and liquefaction reaction of biomass kerosene slurry:

the straw crushed materials and brown coal crushed materials are subjected to ash removal and then mixed with biomass carbon loaded with iron oxide after vulcanization treatment to obtain a mixture, the mixture is added into rancid oil to form biomass kerosene slurry, hydrogen is introduced into the biomass kerosene slurry to perform reaction, the reaction pressure is controlled to be 15MPa, the reaction temperature is controlled to be 440 ℃, and finally the bio-oil is prepared.

In this embodiment, the biomass charcoal loaded with iron oxide is prepared by the following method:

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

(2) and loading the iron oxide subjected to vulcanization treatment on the biomass charcoal carrier to prepare the catalyst.

The specific method for loading the iron oxide subjected to the vulcanization treatment on the biomass charcoal carrier comprises the following steps:

mixing the biomass charcoal carrier and the vulcanized iron oxide aqueous solution to prepare a suspension, adding a precipitator to precipitate the vulcanized iron oxide on the biomass charcoal carrier, and washing and drying to prepare the 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;

example 3

A co-liquefaction process of coal and biomass comprises the following steps:

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 materials of the reeds into a briquetting machine or a plodder for extrusion forming at 50 ℃, wherein the forming pressure is 3MPa, so as to obtain the compressed material of the reeds.

(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 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 at 55 ℃, 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 D₅₀Is 40 μm for standby.

Preparation and liquefaction reaction of biomass kerosene slurry:

and (3) deashing the secondary crushed material of the reed and the coal, mixing the deashed secondary crushed material with the biomass charcoal loaded with the iron oxyhydroxide subjected to vulcanization treatment in the reactor to obtain a mixture, and adding the mixture into the waste engine oil to form the biomass coal oil slurry. In a preferred embodiment, the biomass kerosene slurry can be further processed by a colloid mill, and the slurrification property of the biomass kerosene slurry can be further improved.

And introducing hydrogen into the biomass kerosene slurry to react, and controlling the reaction pressure to be 17MPa and the reaction temperature to be 400 ℃ to finally prepare the bio-oil. In the biomass kerosene slurry, the reed content is 30 wt%, the coal content is 40 wt%, the catalyst content is 0.1 wt%, and the particle size of the catalyst is 500 μm.

Example 4

A co-liquefaction process of coal and biomass comprises the following steps:

pretreatment of the biomass raw material:

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

(2) And (3) sending the primary crushed material of the leaves into a briquetting machine or a plodder for extrusion forming at 40 ℃, wherein the forming pressure is 2MPa, and obtaining the compressed material of the leaves.

(3) Feeding the compressed leaf material into a jet mill, and performing secondary grinding to obtain secondary crushed material with particle size D₅₀50 μm for use.

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 D₅₀And 60 μm.

(2) And (3) sending the crushed material of the Shendong long flame coal into a briquetting machine or a plodder for extrusion forming at 45 ℃, 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 D₅₀50 μm for use.

Preparation and liquefaction reaction of biomass kerosene slurry:

the method comprises the steps of drying, crushing and ash removing leaves, mixing the dried, crushed and ash removed leaves with biomass charcoal loaded with ferric hydroxide and subjected to vulcanization treatment in a reactor to obtain a mixture, adding the mixture into heavy oil to form the biomass coal oil slurry, and treating the biomass coal oil slurry through a colloid mill to continuously improve the slurry forming property of the biomass coal oil slurry.

And introducing hydrogen into the biomass kerosene slurry passing through the colloid mill to react, controlling the reaction pressure to be 19MPa and the reaction temperature to be 380 ℃, and finally preparing the bio-oil. In the biomass coal oil slurry, the content of the leaves is 20 wt%, the content of the coal is 45 wt%, the content of the catalyst is 2 wt%, and the particle size of the catalyst is 400 μm.

Example 5

A co-liquefaction process of coal and biomass comprises the following steps:

pretreatment of the biomass raw material:

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

(2) And (3) sending the primary crushed algae into a briquetting machine or a plodder for extrusion forming at 45 ℃, wherein the forming pressure is 2MPa, and obtaining 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 D₅₀And 80 μm.

(2) And (3) conveying the primary pulverized lignite into a briquetting machine or a plodder for extrusion forming at 60 ℃, wherein the forming 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 kerosene slurry.

Preparation and liquefaction reaction of biomass kerosene slurry:

the secondary crushed material of the algae and the lignite after screening is subjected to ash removal and then is mixed with amorphous iron oxyhydroxide after vulcanization treatment in a reactor to obtain a mixture, the mixture is added into the bio-oil prepared by the process to form the biomass coal oil slurry, hydrogen is introduced into the biomass coal oil slurry to perform reaction, the reaction pressure is controlled to be 20MPa, and the reaction temperature is controlled to be 390 ℃, so that the bio-oil is finally prepared. Wherein the mass ratio of the sulfur to the amorphous iron oxyhydroxide is 0.4: 1 mixing and preparing to obtain the catalyst. In the biomass coal oil slurry, the content of algae is 20 wt%, the content of coal is 40 wt%, the content of the catalyst is 4 wt%, and the particle size of the catalyst is 300 μm.

The specific method for introducing the hydrogen comprises the following steps: injecting high-pressure hydrogen into the biomass kerosene slurry, and controlling the volume ratio of the high-pressure hydrogen to the biomass kerosene slurry to be 600: 1, thereby forming a reaction feedstock; feeding the reaction raw materials into a slurry bed reactor to carry out liquefaction, cracking and hydrogenation reactions, and simultaneously injecting high-pressure cold hydrogen into the slurry bed reactor, wherein the total gas velocity in the slurry bed reactor is controlled to be 0.2 m/s; wherein the pressure of the high-pressure hydrogen and the pressure of the high-pressure cold hydrogen are both 13MPa, and the temperature of the high-pressure cold hydrogen is 135 ℃.

Example 6

A co-liquefaction process of coal and biomass comprises the following steps:

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 200 μm.

(2) And (3) feeding the crushed soybean oil residue into a briquetting machine or a plodder for extrusion forming at 550 ℃, wherein the forming pressure is 4MPa, 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 D₅₀Is 40 μm for standby.

Pretreating a coal raw material:

(2) And (3) sending the crushed material of the Shendong long flame coal into a briquetting machine or a plodder for extrusion forming at 55 ℃, wherein the forming pressure is 10MPa, so as to obtain the Shendong long flame coal compression material.

Preparation and liquefaction reaction of biomass kerosene slurry:

the secondary crushed materials of the Shendong long flame coal and the soybean oil residue and the amorphous iron oxyhydroxide which is subjected to the vulcanization treatment in the reactor are added into the waste lubricating oil together, so that the biomass coal oil slurry is formed.

And introducing hydrogen into the biomass kerosene slurry to perform reaction, controlling the reaction pressure to be 22MPa, the reaction temperature to be 410 ℃, and the reaction time to be 30min, thereby finally preparing the bio-oil. Wherein the mass ratio of the sulfur to the amorphous iron oxyhydroxide is 0.8: 1 mixing and preparing to obtain the catalyst. In the biomass coal oil slurry, the content of the soybean oil dregs is 30 wt%, the content of the coal is 30 wt%, the content of the catalyst is 6 wt%, and the particle size of the catalyst is 200 μm.

The specific method for introducing the hydrogen 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 kerosene slurry for the first time, the biomass kerosene 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 kerosene slurry for the second time, and the volume ratio of the high-pressure hydrogen injected twice to the biomass kerosene slurry is controlled to be 700: 1, thereby forming a reaction feedstock; the reaction raw materials are sent into a slurry bed reactor to carry out liquefaction, cracking and hydrogenation reactions, high-pressure cold hydrogen with the pressure of 18MPa and the temperature of 100 ℃ is injected into the slurry bed reactor, the cold hydrogen is injected through 5 injection ports on the side wall of the slurry bed reactor, and the total gas velocity in the slurry bed reactor is controlled to be 0.08 m/s.

Example 7

A co-liquefaction process of coal and biomass comprises the following steps:

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, crushing the rice straws, the palm oil residues and the lignite to obtain powder with a median particle size of 100 mu m, and then sending the powder into a briquetting machine or a plodder together for extrusion forming under the forming pressure of 5MPa to obtain the rice straw, palm oil residues and lignite compression material. And (3) feeding the compressed material into a ball mill, and crushing to obtain crushed materials of rice straws, palm oil residues and lignite with median particle sizes of 30 mu m for later use.

Preparation and liquefaction reaction of biomass kerosene slurry:

and (2) deashing the crushed material, mixing the deashed crushed material with vulcanized amorphous iron oxyhydroxide in a reactor to obtain a mixture, adding the mixture into the mixed coal tar and petroleum to form the biomass coal oil slurry, introducing hydrogen into the biomass coal oil slurry to perform reaction, controlling the reaction pressure to be 23MPa, the reaction temperature to be 450 ℃ and the reaction time to be 60min, and finally preparing the bio-oil. Wherein the mass ratio of the sulfur to the amorphous iron oxyhydroxide is 0.6: 1 mixing and preparing to obtain the catalyst. In the biomass coal oil slurry, the content of palm oil residues is 20 wt%, the content of rice straws is 10 wt%, the content of coal is 40 wt%, the content of a catalyst is 8 wt%, and the particle size of the catalyst is 100 μm.

The specific method for introducing the hydrogen comprises the following steps:

after high-pressure medium-temperature hydrogen with the pressure of 23MPa and the temperature of 350 ℃ is injected into the biomass kerosene slurry for the first time, the biomass kerosene slurry is subjected to heat exchange and is heated to 400 ℃, then high-pressure high-temperature hydrogen with the pressure of 23MPa and the temperature of 510 ℃ is injected into the biomass kerosene slurry for the second time, and the volume ratio of the high-pressure hydrogen injected twice to the biomass kerosene slurry is controlled to be 800: 1, thereby forming a reaction feedstock; and (2) sending the reaction raw materials into a slurry bed reactor to carry out liquefaction, cracking and hydrogenation reactions, simultaneously injecting high-pressure cold hydrogen with the pressure of 23MPa and the temperature of 80 ℃ into the slurry bed reactor, injecting the cold hydrogen through 4 injection ports on the side wall of the slurry bed reactor, and controlling the total gas velocity in the slurry bed reactor to be 0.05 m/s. The inventory of the catalyst in the slurry bed reactor is controlled to be 30 wt% of the mass of the liquid phase in the slurry bed reactor.

Example 8

A co-liquefaction process of coal and biomass comprises the following steps:

pretreatment of the biomass raw material:

(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.

Pretreating a coal raw material:

(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 lignite compressed material into a ball mill for secondary crushing,obtaining the secondary crushed material of the brown coal with the grain diameter D₅₀35 μm for use.

The preparation and liquefaction process of the biomass kerosene slurry comprises the following steps:

and adding the reed and the lignite which are subjected to secondary crushing into washing oil, so as to form the biomass kerosene slurry. In a preferred embodiment, the biomass kerosene slurry is further processed by a colloid mill, and the slurrification property of the biomass kerosene slurry can be further improved.

And introducing hydrogen into the biomass kerosene slurry to perform reaction, controlling the reaction pressure to be 25MPa, the reaction temperature to be 380 ℃, and the reaction time to be 90min to finally prepare the bio-oil. Wherein the sulfur and the amorphous iron oxyhydroxide are mixed according to a mass ratio of 1: 1 mixing and preparing to obtain the catalyst. In the biomass kerosene slurry, the reed content is 25 wt%, the coal content is 40 wt%, the catalyst content is 10 wt%, and the particle size of the catalyst is 5 μm. The specific method for introducing the hydrogen comprises the following steps:

after injecting high-pressure medium-temperature hydrogen with the pressure of 27MPa and the temperature of 360 ℃ into the biomass kerosene slurry for the first time, carrying out heat exchange on the biomass kerosene slurry and heating the biomass kerosene slurry to 420 ℃, then injecting high-pressure high-temperature hydrogen with the pressure of 27MPa and the temperature of 440 ℃ into the biomass kerosene slurry for the second time, and controlling the volume ratio of the high-pressure hydrogen to the biomass kerosene slurry to be 1000: 1, thereby forming a reaction feedstock; the reaction raw materials are sent into a slurry bed reactor to carry out liquefaction, cracking and hydrogenation reactions, high-pressure cold hydrogen with the pressure of 27MPa and the temperature of 50 ℃ is injected into the slurry bed reactor, the cold hydrogen is injected through 3 injection ports on the side wall of the slurry bed reactor, and the total gas velocity in the slurry bed reactor is controlled to be 0.02 m/s. The inventory of the catalyst in the slurry bed reactor is controlled to be 5 wt% of the mass of the liquid phase in the slurry bed reactor.

Comparative example 1

A co-liquefaction process of coal and biomass comprises the following steps:

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 or a plodder for extrusion forming at 15MPa to obtain the lignite compression material. And (3) feeding the lignite compressed material into a hammer crusher for crushing to obtain pulverized lignite with the particle size of 30 mu m. Adding the pulverized lignite and the amorphous iron oxyhydroxide which is subjected to vulcanization treatment in the reactor into a mixture of liquid excrement and waste engine oil to form biomass kerosene slurry, introducing hydrogen into the biomass kerosene 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 co-liquefaction process of coal and biomass comprises the following steps:

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 or a plodder for extrusion forming at 15MPa to obtain the lignite compression material. And (3) feeding the lignite compressed material into a hammer crusher for crushing to obtain pulverized lignite with the particle size of 30 mu m. Adding the pulverized lignite and an oil-soluble dispersed hydrogenation catalyst subjected to vulcanization treatment in a reactor into a mixture of liquid excrement and waste engine oil to form biomass coal oil slurry, introducing hydrogen into the biomass coal oil slurry to perform reaction, and controlling the reaction pressure to be 16MPa and the reaction temperature to be 480 ℃ to finally prepare the bio-oil.

The process effects of the inventive examples and the comparative examples were compared, and the results are 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 co-conversion rate of biomass and coal and the yield of bio-oil obtained by the process of the present invention are both high, and the amount of residue is significantly reduced, so that the method of the present invention can significantly improve the conversion rate of biomass and the yield of bio-oil and reduce the amount of residue.

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 co-liquefaction process of coal and biomass is characterized by comprising the following steps:

preparing biomass kerosene slurry:

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

in the step of preparing the biomass coal oil slurry, when mixing, the biomass powder and the coal powder are firstly deashed and premixed with the catalyst, and then the obtained premix is mixed with the oil product, or the biomass powder, the coal powder, the catalyst and the oil product are directly mixed;

in the biomass kerosene slurry, the concentration of biomass is 20-30 wt%, and the concentration of pulverized coal is 30-45 wt%;

the specific method for introducing the hydrogen comprises the following steps:

feeding the reaction raw materials into a slurry bed reactor to carry out liquefaction, cracking and hydrogenation reactions, and injecting high-pressure cold hydrogen into the slurry bed reactor at the same time, wherein the total gas velocity in the slurry bed reactor is controlled to be 0.02-0.2 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 oil product is one or more of hogwash oil, swill-cooked dirty oil, rancid oil and waste lubricating oil;

the viscosity of the biomass kerosene slurry is 550-1000mPa & s at 50 ℃.

2. The co-liquefaction process of coal and biomass according to claim 1, characterized in that the moisture content is controlled by drying and dehydration at 50-70 ℃ for 3-5 hours.

3. The co-liquefaction process of coal and biomass according to claim 1 or 2, wherein the bulk density of the biomass powder is controlled to be 300-500 kg/m in the preparation step of the biomass coal oil slurry³Controlling the bulk density of the pulverized coal to be 1000-1200 kg/m³。

4. The co-liquefaction process of coal and biomass according to claim 3, characterized in that the time of the grinding and pulping is 2-8 min.

5. The co-liquefaction process of coal and biomass according to claim 1, characterized in that the coal is low-rank coal.

6. The co-liquefaction process of coal and biomass according to claim 1, wherein the content of the catalyst in the biomass coal oil slurry is 0.1-10 wt%; the particle size of the catalyst is 5-500 μm.

7. The process of co-liquefaction of coal and biomass according to claim 6, characterized in that the catalyst content in the biomass coal oil slurry is 2 wt%.

8. The process for the co-liquefaction of coal and biomass according to claim 1, wherein in the specific method of introducing hydrogen,

and controlling the total gas velocity in the slurry bed reactor to be 0.05-0.08 m/s.

9. The co-liquefaction process of coal and biomass according to claim 8, characterized in that the high pressure hydrogen is injected into the biomass kerosene slurry in two portions, in particular:

10. The co-liquefaction process of coal and biomass according to claim 8 or 9, characterized in that the inventory of the catalyst in the slurry bed reactor is controlled to be 5-30 wt% of the mass of the liquid phase in the slurry bed reactor.

11. The co-liquefaction process of coal and biomass according to claim 1, characterized in that the reaction time is 30-90 min.

12. The co-liquefaction process of coal and biomass according to claim 1 or 6, characterized in that the catalyst is a sulfided biomass char loaded with active components, the active components being one or more of iron oxide, iron oxyhydroxide or iron hydroxide;

or the catalyst is amorphous iron oxyhydroxide after vulcanization treatment.

13. The co-liquefaction process of coal and biomass according to claim 1, characterized in that the oil product is a used oil.