CN116116449A

CN116116449A - Nitrogen-doped biochar-based bio-oil upgrading catalyst and preparation method and application thereof

Info

Publication number: CN116116449A
Application number: CN202310082873.0A
Authority: CN
Inventors: 江霞; 彭琴; 靳紫恒; 何璟琳
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2023-01-17
Filing date: 2023-01-17
Publication date: 2023-05-16
Anticipated expiration: 2043-01-17
Also published as: CN116116449B

Abstract

The invention relates to a nitrogen-doped biochar-based bio-oil upgrading catalyst, a preparation method and application thereof, and relates to the technical field of resource carbon neutralization. The nitrogen-doped biochar-based bio-oil upgrading catalyst takes nitrogen-doped biochar as a carrier and one or more than two metals in the VIII group as active components; the carrier is prepared from biomass, polyacrylonitrile and M _x O _y Made into M _x O _y Wherein M is an element in IIIA, IVA, IVB, VB, VIB or VIIB; the mass fraction of the active component loaded on the carrier is 2-15%. The catalyst can effectively overcome the problems of low strength, easy deactivation and the like of the traditional catalyst; under the conditions of 300 ℃ and 2-4 MPa, the conversion rate of the guaiacol is up to 100%, the deoxidization rate is up to 96.7%, the main product is cyclohexane, the selectivity is up to 90%, and after the catalyst continuously reacts for 45 hours, the conversion rate of the guaiacol is still stable at 99%4%, and the deoxidization rate of the product is stabilized at 80%.

Description

Nitrogen-doped biochar-based bio-oil upgrading catalyst and preparation method and application thereof

Technical Field

The invention relates to the technical field of resource carbon neutralization, in particular to a nitrogen-doped biochar-based bio-oil upgrading catalyst and a preparation method and application thereof.

Background

The global warming is exacerbated by the massive use of fossil energy by human society, while promoting rapid economic development. Statistics from the International Energy Agency (IEA) indicate that the global energy related carbon dioxide emissions of 2021 breaks through 363 billions of tons, with petroleum usage yielding carbon emissions of 107 billions of tons, at a rate of 29%. The first and second large petroleum importation countries in the world have the dependence of petroleum resources up to 70%, and the carbon dioxide emission produced by petroleum combustion is about 14 hundred million tons/year. With the aim of carbon neutralization, the path of future development is the transition from a raw material system of fossil energy to a raw material system of renewable energy.

Biomass energy is formed by carbon dioxide and water in the atmosphere under photosynthesis, and is a world-recognized renewable resource with zero carbon properties. Biomass resources on the earth are abundant, and the biomass resources are the circulating carbon resources which have the highest potential to replace fossil resources on a large scale. The '3060 blue book' with zero carbon biomass energy development potential shows that the annual biomass yield in China exceeds 35 hundred million tons, the development potential is about 4.6 hundred million tons of standard coal, only 0.6 hundred million tons of standard coal is actually developed at present, and the carbon emission reduction potential brought by the mature application of biomass resource substitution technology is expected to be about 20 hundred million tons. Therefore, development of biomass is converted into liquid fuel technology revolution, dependence on primary fossil resources is reduced, and substitution and transformation of renewable resources on the surface are promoted, so that the method has great significance for realizing carbon neutralization in China.

Biomass encompasses all animals, plants and their derivatives and waste, where vegetative biomass is composed mainly of macromolecules such as cellulose, hemicellulose and lignin. The biomass oxygen content is about 50% higher, resulting in low energy density and low calorific value, and thus the key problem faced in developing biomass alternative fuels is deoxygenation. Attempts have been made internationally to develop a biomass fast pyrolysis partial deoxidization to obtain pyrolysis oil, and the catalytic hydrogenation extraction is used for precisely breaking bonds of C-O and c=o in the pyrolysis oil to deoxidize, so that high-grade hydrocarbon fuel with combustion performance similar to that of gasoline, diesel or aviation kerosene is obtained through conversion. In this technical path, the key core is to develop a catalyst with high catalytic activity, selectivity and long service life for the hydrogenation upgrading of pyrolysis oil. CN110028982 a discloses a biomass pyrolysis liquid ebullated bed hydrodeoxygenation catalyst, a preparation method and application thereof, the catalyst is a supported spherical catalyst, wherein the active metal component comprises a VIII metal or a VIII metal added with one or two of the metals of the VB, VIB, VIIB, IB and IIB, and the carrier is a spherical wear-resistant carbon-based material prepared by using a high molecular polymer as a carbon precursor. The content of the catalyst carrier is 82-96 wt% and the content of the active metal is 4-18 wt%. However, the selectivity and the cycle stability of the catalyst to hydrocarbon products are not clear.

Guaiacol is an exemplary representation of an oxygen-containing compound generated after pyrolysis of lignin which is a main component in biomass, and molecules of the guaiacol simultaneously contain benzene rings, phenolic hydroxyl groups and methoxy groups, and hydrocarbon substances such as aliphatic hydrocarbon, cycloparaffin, alkyl cycloparaffin, benzene, alkylbenzene and the like are prepared by taking the guaiacol as a model substance through hydrogenation and upgrading, and the guaiacol has the carbon number of 5-7, is a constituent component of gasoline, and can replace hydrocarbon fuel. The distribution of the products of one-step catalytic hydrogenation reactions has been studied in literature using guaiacol as a model. As patent CN102430409A, a ZrO-based catalyst is proposed ₂ -SiO ₂ The preparation method of the catalyst with binary composite oxide loaded with binary active metals Ni and Cu comprises the steps of performing catalytic conversion reaction evaluation on an n-octane solution of guaiacol (the mass fraction of guaiacol is 10%) when the temperature is set to 300 ℃ and the hydrogen pressure is 5MPa in a kettle-type reactor, wherein the conversion rate of guaiacol is close to 100%, and the maximum alkane yield is 62.7%. Lee et al (Catalysis Communications,2012,17 (2012): 54-58) prepared Rh/SiO ₂ -Al ₂ O ₃ And Ru/SiO ₂ -Al ₂ O ₃ The conversion rate of the catalytic reaction on guaiacol is up to 100%, and the selectivity of cyclohexane in the upgraded product is in the range of 17-60%. The catalyst is micron-sized powder, and is molded by a proper method before use, so that catalyst loss, sintering and influence on pressure drop of a reactor in the reaction process are reduced, and the process is complicated. Alumina has poor water resistance and acid resistance, is not suitable for biological oil upgrading reaction with high water content and high organic acid content, and has short service life due to easy collapse of the alumina carrier framework to cause catalyst deactivation. Niu Xiaopo et al (chemical engineering report, 2021,72 (5): 2616-2625) employ dissolution-recrystalization The hollow ZSM-5 molecular sieves with different silicon-aluminum ratios are synthesized by a crystallization method, noble metal Pt is loaded on the hollow ZSM-5 molecular sieves to form Pt/HZ-x catalysts, the Pt/HZ-x catalysts are used for hydroconversion research of guaiacol, the guaiacol conversion rate reaches 100% at the temperature of 260 ℃, and main deoxidization products are cyclopentane, methylcyclopentane and cyclohexane, and a small amount of cyclohexene and methylcyclohexane exist. The enhanced acidity of the molecular sieve catalyst promotes the isomerization reaction of cyclohexane, thereby reducing cyclohexane selectivity. The inherent microporous structure of molecular sieves can limit reactant mass transfer and product diffusion, exacerbating carbon formation, and thus leading to rapid catalyst deactivation during hydrogenation, shortening life.

The catalyst for catalyzing guaiacol to produce cyclohexane has high cost by taking noble metal as an active center or has low alkane yield by taking non-noble metal as an active center; in addition, the catalyst prepared by taking the metal oxide powder as a carrier has the disadvantages of reduced activity, poor compressive strength, short service life and the like due to post-forming. The cost and the reusability of the catalyst are also important indexes, and the prior art is difficult to meet the industrial requirement of the large-scale catalyst. In view of the above, a nitrogen-doped biochar-based bio-oil upgrading catalyst and a preparation method and application thereof are provided.

Disclosure of Invention

The invention aims to solve the technical problem of providing a nitrogen-doped biochar-based bio-oil upgrading catalyst as well as a preparation method and application thereof. The invention aims to provide a catalyst with high strength, excellent pore structure and stable activity, and simultaneously meets the requirement of high-efficiency hydrodeoxygenation conversion of biological oil model compounds such as guaiacol, and the selectivity of cyclohexane as a main product is high.

The present invention has been made to solve the above-mentioned problems, and a first object is to provide a nitrogen-doped biochar-based bio-oil upgrading catalyst (A/M _x O _y -NC), the nitrogen-doped biochar-based bio-oil upgrading catalyst uses nitrogen-doped biochar as a carrier, and one or more metals of group VIII as active components, the active components being supported on the carrier; the carrier is composed of biomass, polyacrylonitrile and M _x O _y Is made into, the rawSubstance powder, M _x O _y And the mass ratio of the polyacrylonitrile is (2-4) (0.4-2) (2-4); the M is _x O _y Wherein M is one element of IIIA, IVA, IVB, VB, VIB or VIIB, x is 1-2, and y is 2-5; the mass fraction of the active component loaded on the carrier is 2-15%.

The beneficial effects of the invention are as follows: the invention can effectively overcome the problems of low strength, easy inactivation, short service life and the like of the traditional catalyst, adopts biomass as a carbon source, and adopts polyacrylonitrile and a solvent to jointly provide a bonding effect for the ball precursor, M _x O _y The preparation process is simple and easy to control, the polyacrylonitrile and the solvent contain nitrogen, the carbon is prepared by one-step nitrogen doping, the size and the morphology of the carbon sphere are easy to adjust, the doping of nitrogen can enhance the dispersibility of the supported metal and the anchoring strength of the supported metal, and the electron transfer is promoted in the hydrogenation reaction, so that the hydrodeoxygenation efficiency is improved.

The A/M obtained by the invention _x O _y The NC catalyst is of a carbon sphere structure with orderly distributed micro-meso-macroporous gradient pore channels, the conversion rate of guaiacol is up to 100%, the deoxidization rate is up to 96.7%, the main product is cyclohexane, the selectivity is up to 90%, the guaiacol conversion rate is still stable at 99.4% and the deoxidization rate of the product is stable at 80% after the catalyst continuously reacts for 45h under the condition of 300 ℃ and 2-4 MPa.

On the basis of the technical scheme, the invention can be improved as follows.

Further, the nitrogen-doped biochar-based bio-oil upgrading catalyst is spherical particles, the size of the spherical particles is 0.5-2.0 mm, and the specific surface area is 200-1000 m ² Per gram, the total pore volume is 0.20-0.80 cm ³ And/g, wherein the nitrogen-doped biochar-based bio-oil upgrading catalyst is internally provided with a gradient pore channel structure with micropores, mesopores and macropores distributed, and the compressive strength of the single catalyst is not less than 22N/particle.

Further, the nitrogen doping content of the nitrogen doped biochar-based bio-oil upgrading catalyst is 4.0-12.0%. The nitrogen content is the ratio of nitrogen to the sum of these elements C, N, O, H.

Further, the biomass in the carrier is at least one of shells (such as walnut shell powder), woods (such as poplar powder) and straws; the M is _x O _y Is Al ₂ O ₃ 、ZrO ₂ 、Nb ₂ O ₅ 、SiO ₂ 、TiO ₂ 、CeO ₂ At least one of them.

The second aim is to provide a preparation method of the nitrogen-doped biochar-based bio-oil upgrading catalyst, which comprises the following steps:

step 1, preparing a suspension: biomass powder, M _x O _y Uniformly mixing the mixture with polyacrylonitrile, then adding a polar organic solvent, and heating and stirring to enhance the dispersibility of the mixed solution, thus obtaining a uniformly distributed suspension;

step 2, preparing a nitrogen-doped biochar-based ball precursor: filling the suspension liquid which is uniformly distributed in the step 1 into an injection tube, and performing ball dripping operation on the injection tube into the ethanol aqueous solution of the coagulating bath by using a uniform-speed driving force to obtain a carbon-based ball precursor;

step 3, drying, oxidizing, carbonizing and activating the carbon-based ball precursor: repeatedly ultrasonic soaking and washing the carbon-based ball precursor in the step 2 with water, and drying, oxidizing, carbonizing and activating to obtain M _x O _y -NC carbon sphere particle carriers;

step 4, active component loading: obtaining M in the step 3 _x O _y NC carbon sphere particle carrier, active component is loaded on M by wet dipping method _x O _y And (3) drying, roasting and reducing the NC carbon sphere particle carrier in the outer surface and the inner pore canal to obtain the nitrogen doped biochar-based bio-oil upgrading catalyst.

The beneficial effects of adopting above-mentioned scheme are: the preparation method provided by the invention uses waste biomass as a carbon source, polyacrylonitrile as a carbon source, a nitrogen source and a binder, and M _x O _y As an acid modification site of the auxiliary agent, a uniform mixed solution is formed in the polar organic solvent, the polar organic solvent in the nitrogen-doped carbon-based sphere precursor is rapidly dissolved into the ethanol aqueous solution by dripping the spheres into the ethanol aqueous solution, and then the solvent is facilitated to be dissolved by soaking and washing for multiple timesForming a multi-channel aperture structure; then oxidizing, carbonizing and activating the carbon spheres to further shrink so as to form a carbon sphere structure with uniformly distributed micro-meso-macroporous gradient multistage pore distribution on the surface hardening layer and sphere cavities; and then active component metal is loaded on the nitrogen-doped carbon sphere carrier, so that the dispersibility and stability of the nitrogen-doped carbon sphere carrier are improved.

Further, the biomass powder, M in step 1 _x O _y The mixing mass ratio of the polyacrylonitrile to the polyacrylonitrile is (2-4) (0.4-2) (2-4); the polar organic solvent is at least one of N, N-dimethylformamide, dimethylacetamide and N-methylpyrrolidone; in the step 1, the heating temperature is 60-80 ℃, for example, water bath heating is adopted, and the rotating speed of an electric stirrer is 2000-5000 r/min, for example, an electric stirrer is adopted.

Biomass powder, M in the present invention _x O _y And the ratio between the polyacrylonitrile solid raw materials, and the ratio of the total solid to the organic solvent are key parameters. If biomass powder, M _x O _y And the total solid content of the polyacrylonitrile is too high, the mixed liquid is too viscous, and the dropped balls can have serious tailing phenomenon; on the other hand, if the amount of solids is small, particularly if the proportion of polyacrylonitrile is too low, spherical carbon may not be obtained. M is M _x O _y The ratio of the ratio to the ratio affects the acid strength and water resistance of the catalyst, and ultimately affects the catalyst's efficiency of the guaiacol deoxygenation. The invention controls the biomass powder, M _x O _y And polyacrylonitrile in a mixing ratio of 2-4:0.4-2:2-4, wherein the total solid content accounts for 12.5-17.5% of the total solid content and the total mass of the organic solvent, and M is as follows _x O _y The content of the suspension is 1 to 5 percent, and the A/M with the best performance is obtained _x O _y -NC。

In addition, polyacrylonitrile is heated in water bath at 60-80 deg.c to dissolve in organic solvent fully. When the raw materials are heated in a water bath, an electric stirrer is used for rapid stirring, so that the organic solvent and the polyacrylonitrile are fully dissolved into homogeneous liquid, biomass powder and M _x O _y Evenly dispersed in the liquid, and is easier to form in the subsequent ball dropping process The internal structure is uniformly distributed. If the rotating speed is too low, the particles in the sphere are finally unevenly dispersed, and the metal-loaded guide is easy to agglomerate. If the rotating speed is too high, larger air bubbles are easy to close, and hollows and bubbles are formed in the ball body during ball dripping, so that a ball cavity structure with large specific surface area and uniform pores is not beneficial to manufacture. Therefore, the invention controls the rotating speed of the electric stirrer to be 2000-5000 r/min, preferably 2000r/min.

In the step 2, the inner diameter of the needle head of the injection tube is 1.00-2.0 mm, and the constant-speed pushing rate of the injection tube is controlled to be 120-180 mL/h; the mass concentration of the coagulating bath ethanol water solution is 25-45%.

In the step 3, the ultrasonic time is 15-45 min; the drying is constant temperature air blast drying. The oxidation is carried out for 3 to 8 hours at a gradient temperature rise between 180 and 290 ℃, the air flow is 50 to 60mL/min, and the temperature rise rate is 1 to 5 ℃/min; in a preferred mode, the temperature is raised to 180-200 ℃ for 0.5-1.5 h, then 210-230 ℃ for 0.5-1.5 h, 240-250 ℃ for 0.5-1.5 h, 260-270 ℃ for 0.5-1.5 h, and 280-290 ℃ for 1-2 h. The carbonization and the activation are continuous processes, the heating rate of the carbonization and the activation is 1-10 ℃/min, and the nitrogen flow is 100-300 mL/min; the carbonization temperature is 550-750 ℃ and the carbonization time is 1-3 h; the activation temperature is 800-900 ℃ and the activation time is 30-60 min.

The rate of the drop balls of the present invention affects how smooth the ball looks and whether or not micron-sized small ball particles are associated, so it is important to select an appropriate drop ball rate. If the flow rate of the solution in the injection tube is too fast, the solution can be in a strip shape; if the flow rate of the solution in the injection tube is too slow, a few tiny micron-sized pellets are easy to accompany, on one hand, the utilization efficiency of substances is affected, and on the other hand, the screening procedure is additionally added in the follow-up procedure. The invention controls the flow rate of the solution in the injection tube to be 120-180 mL/h, the inner diameter of the needle head is 1.00-2.0 mm, preferably the inner diameter of the needle head is 1.55mm, and uniform millimeter-grade spherical carbon particles can be obtained. In addition, the flow rate of the solution in the injection tube and the inner diameter of the needle head can be reasonably adjusted according to the requirement on the particle size of the product. By controlling the aperture of the injection tube needle and the flow rate of the liquid, the particle size of the catalyst obtained by the invention is in millimeter level, and the particle size is 0.5-2.0 mm.

The coagulating bath of the liquid drop is ethanol water solution, because the density of the pellets is smaller than that of water, if pure water solution is used, the pellets which are firstly dripped all float on the water surface, so that no space is reserved for receiving the residual pellets, and the organic solvent is prevented from being dissolved out due to the lack of sinking of the pellets, so that the pore-forming effect is poor. The mass concentration of the ethanol aqueous solution is controlled to be 25-45%. After the pellets are solidified in ethanol water solution, repeatedly soaking and washing with water, and preferably ultrasonic washing for 15-45 min. And the subsequent drying adopts constant-temperature air blast drying, and is heated uniformly. Then oxidation, carbonization and activation are carried out, wherein the purpose of oxidation is that polyacrylonitrile is subjected to dehydrogenation, cyclization and oxidation reaction; the carbonization aim is to carry out slow pyrolysis on biomass powder or polyacrylonitrile to prepare carbon materials, and simultaneously reduce the pore canal in the spherical cavity, thereby finally preparing the nitrogen-doped biochar sphere with rich pore canal structure network; the purpose of using the water vapor as an activation medium is that the water vapor reacts with carbon material in a carbon-water reaction, partial carbon elements are removed by oxidization, rich micropore and mesopore structures are formed, and the specific surface area of the carbon sphere is enlarged.

In the step 4, the active component is derived from a metal salt solution, and the mass concentration of the metal element in the carrier is 2-15%, namely the metal element accounts for the mass percent of the carrier; more preferably 10 to 15%. The drying is that firstly, the drying is carried out in a water bath environment with the temperature of 40-60 ℃, and then the drying is carried out in a blast drying oven with the constant temperature of 60-80 ℃; the temperature rise rate of the roasting is 1-10 ℃/min, the roasting temperature is 450-550 ℃, and the roasting time is 1-3 h; the reduction temperature is 300-450 ℃, the heating rate is 1-10 ℃/min, the reduction gas is one of hydrogen gas or hydrogen-argon mixed gas (in any proportion), and the reduction time is 1-3 h.

According to the method, an active component A metal salt solution is prepared according to calculated amount, the calculated amount of nitrogen-doped biochar balls are mixed with the A metal salt solution by adopting a wet impregnation method, proper low temperature is selected for drying, water is slowly evaporated, and then the mixture is dried in a constant temperature blast drying box, so that the phenomenon that metal salt is deposited on the surface of a carrier due to too high drying temperature and metal agglomeration occurs after roasting is avoided.

A third object is to provide an application of the nitrogen-doped biochar-based bio-oil upgrading catalyst in biomass hydrogenation upgrading to produce liquid fuel.

Further, guaiacol is used as a biomass model, and the mass airspeed of the reaction for generating liquid fuel by hydrogenation upgrading is 0.5-1.0 h ^-1 Hydrogen volume/raw material volume=600-900L/L, and reaction pressure is 2-4 MPa.

The beneficial effects of adopting the further scheme are as follows: the invention provides the nitrogen-doped biochar ball catalyst for hydrodeoxygenation of guaiacol, which has the conversion rate of guaiacol up to 100%, the deoxidization rate of 96.7%, the main product of cyclohexane, the selectivity of 90%, and the guaiacol conversion rate of 99.4% and the product deoxidization rate of 80% under the conditions of 300 ℃ and 2-4 MPa, wherein the catalyst is continuously reacted for 45 hours.

Drawings

FIG. 1 is a schematic process of preparing nitrogen-doped biochar balls by the injection of the dropping ball method of the invention;

FIG. 2 is the walnut shell powder and Al in example 1 ₂ O ₃ And polyacrylonitrile in a mixing ratio of 3:1:3; (a) morphology of the microsphere at 200 x magnification; (b) the surface morphology of the spherical catalyst at 20000 x magnification;

FIG. 3 is the walnut shell powder and Al in example 1 ₂ O ₃ And polyacrylonitrile in a mixing ratio of 3:1:3;

FIG. 4 is a mass spectrum of the product of the catalytic hydrodeoxygenation of guaiacol of example 2.

Detailed Description

The principles and features of the present invention are described below with examples given for the purpose of illustration only and are not intended to limit the scope of the invention.

The molecular weight of polyacrylonitrile used in the following examples was 5 ten thousand.

The following examples were conducted in order to facilitate experimental operation, with the reduction step in the catalyst preparation process and subsequent biomass hydrogenation upgrading tests.

EXAMPLE 1Co/Al ₂ O ₃ Preparation and application of NC catalyst

Co/Al ₂ O ₃ -NC catalyst preparation comprising the steps of (as in fig. 1):

(1) Waste walnut shell powder and Al ₂ O ₃ Uniformly mixing polyacrylonitrile with the mass ratio of 3:1:3, and adding an N, N-dimethylformamide solvent, wherein the mass fraction of the solvent is 82.5%; heating in 70deg.C water bath, and stirring with electric stirrer at 3000r/min for 3min to obtain suspension with uniform dispersion.

(2) Filling the suspension into a syringe, sleeving a needle with the inner diameter of 1.55mm, and placing the syringe on a syringe pump with constant-speed driving force; dropwise adding the suspension into an ethanol water solution (the mass concentration is 45%) by power, wherein the adding speed is 150mL/h, and the droplets are dropwise added into the ethanol water for instant solidification; after the dropping ball operation is finished, separating out the carbon-based ball precursor by a filtering mode, soaking the carbon-based ball precursor in pure water for 15min, and repeatedly washing for 8 times to replace redundant solvents in the pore canal in the ball cavity.

(3) After the carbon-based ball precursor is subjected to forced air heating and drying, placing the carbon-based ball precursor into a tube furnace, and introducing air with the flow rate of 60 mL/min; step-type programmed temperature oxidation reaction is carried out by heating to 180 ℃ for 1h, 210 ℃ for 1h, 240 ℃ for 1h,260 ℃ for 1h and 280 ℃ for 1.5 h; cooling to room temperature, changing the flow rate of nitrogen into 100mL/min, heating to 750 ℃ at 3 ℃/min, keeping for 2 hours, continuously heating to 850 ℃, changing the flow rate of water vapor, continuously keeping for 1 hour, and naturally cooling to obtain the nitrogen-doped biochar ball carrier Al ₂ O ₃ -NC。

(4) 3.7g Co (NO) ₃ ) ₂ ·6H ₂ Adding O into 5mL of water, adding 7.5g of carbon sphere carrier after full dissolution, performing ultrasonic dispersion for 15min, and slowly evaporating water in a water bath environment at 50 ℃; drying the evaporated catalyst in an oven at 80 ℃ overnight, then roasting at a heating rate of 3 ℃/min, a roasting temperature of 500 ℃ and a holding time of 3 hours, naturally cooling and preserving to obtain unreduced Co/Al ₂ O ₃ NC catalyst (active component Co mass fraction 10%). Co/Al ₂ O ₃ The surface morphology of the NC catalyst is shown in figure 2, and the catalyst is spherical and internally distributed with pore channels as can be seen from the figure. The X-ray photoelectron spectrum of the nitrogen element is shown in figure 3, which shows that the catalyst contains nitrogen doping, and the nitrogen content is measured and calculated to be 7.2%; the doping of nitrogen element can enhance the dispersibility of the supported metal and the anchoring strength to the metal, and promote electron transfer in hydrogenation reaction, thereby improving hydrodeoxygenation efficiency.

Catalyst Co/Al ₂ O ₃ The application of NC is as follows:

the unreduced Co/Al is obtained by the preparation ₂ O ₃ NC catalyst is filled into a constant temperature area of the fixed bed reactor, and quartz sand and 3mm porcelain balls are sequentially filled at two ends for supporting. Setting the heating rate to 5 ℃/min, and setting the heating rate to 100mL/min H at 300 DEG C ₂ Reducing for 3h under the atmosphere. The temperature is kept unchanged, the reaction pressure is regulated to be 2MPa, the hydrogen flow is 100mL/min, the n-dodecane solution of guaiacol (the mass concentration of guaiacol is 5%) is pumped into a fixed bed reactor through a plunger metering pump, a sample is collected after the guaiacol is stabilized for 3 hours, and the composition analysis is carried out through a gas chromatography-mass spectrometer.

EXAMPLE 2Co/Al ₂ O ₃ Preparation and application of NC catalyst

Co/Al of the present example ₂ O ₃ -NC catalyst preparation comprising the steps of (as in fig. 1):

(1) Waste poplar powder and Al ₂ O ₃ Uniformly mixing polyacrylonitrile with the mass ratio of 2:1:4, and adding an N, N-dimethylformamide solvent, wherein the mass fraction of the solvent is 82.5%; heating in 70deg.C water bath, and stirring with electric stirrer at 3000r/min for 3min to obtain suspension with uniform dispersion.

(3) After the carbon-based ball precursor is subjected to forced air heating and drying, placing the carbon-based ball precursor into a tube furnace, and introducing air with the flow rate of 60 mL/min; sequentially heating to 180 ℃ for 1h, 210 ℃ for 1h, 240 ℃ for 1h,260 ℃ for 1h, and 280 ℃ for 1.5 h; cooling to room temperature, changing nitrogen flow rate to 100mL/min, heating to 700 ℃ at 3 ℃/min, keeping for 2 hours, continuously heating to 800 ℃, changing water vapor, keeping for 1 hour, and naturally cooling to obtain the nitrogen-doped biochar ball carrier Al ₂ O ₃ -NC。

(4) 3.7g Co (NO) ₃ ) ₂ ·6H ₂ Adding O into 5mL of water, adding 7.5g of carbon sphere carrier after full dissolution, performing ultrasonic dispersion for 15min, and slowly evaporating water in a water bath environment at 50 ℃; drying the evaporated catalyst in an oven at 80 ℃ overnight, then roasting at a heating rate of 3 ℃/min, a roasting temperature of 500 ℃ and a holding time of 3 hours, naturally cooling and preserving to obtain unreduced Co/Al ₂ O ₃ NC catalyst (active component Co mass fraction 10%).

Catalyst Co/Al ₂ O ₃ The application of NC is as follows:

by mixing the unreduced Co/Al ₂ O ₃ NC catalyst is filled into a constant temperature area of the fixed bed reactor, and quartz sand and 3mm porcelain balls are sequentially filled at two ends for supporting. Setting the heating rate to 5 ℃/min, and setting the heating rate to 100mL/min H at 300 DEG C ₂ Reducing for 3h under the atmosphere. The temperature is kept unchanged, the reaction pressure is regulated to be 2MPa, the hydrogen flow is 100mL/min, the n-dodecane solution of guaiacol (the mass concentration of guaiacol is 10%) is pumped into a fixed bed reactor through a plunger metering pump, a sample is collected after the guaiacol is stabilized for 3 hours, the composition analysis is carried out through a gas chromatography-mass spectrometer, and the analysis result is shown in figure 4, and the main product is cyclohexane.

EXAMPLE 3Co/Al ₂ O ₃ Preparation and application of NC catalyst

Co/Al of the present example ₂ O ₃ NC catalyst preparation, comprising the steps (e.g., drawing1)：

(1) Waste corn stalk powder and Al ₂ O ₃ Uniformly mixing polyacrylonitrile with the mass ratio of 4:1:2, and adding an N, N-dimethylformamide solvent, wherein the mass fraction of the solvent is 82.5%; heating in 70deg.C water bath, and stirring with electric stirrer at 3000r/min for 3min to obtain suspension with uniform dispersion.

(2) Filling the suspension into a syringe, sleeving a needle with the inner diameter of 1.55mm, and placing the syringe on a syringe pump with constant-speed driving force; dropwise adding the suspension into an ethanol water solution (the mass concentration is 45%) by power, wherein the adding speed is 150mL/h, and the droplets are dropwise added into the ethanol water for instant solidification; after the dropping ball operation is finished, separating out the carbon-based ball precursor by a filtering mode, soaking the carbon-based ball precursor in pure water for 15min by ultrasonic treatment, and repeatedly washing for 10 times to replace redundant solvents in the pore canal in the ball cavity.

(3) After the carbon-based ball precursor is subjected to forced air heating and drying, placing the carbon-based ball precursor into a tube furnace, and introducing air with the flow rate of 60 mL/min; sequentially heating to 180 ℃ for 1h, 210 ℃ for 1h, 240 ℃ for 1h,260 ℃ for 1h, and 280 ℃ for 1.5 h; cooling to room temperature, changing nitrogen flow rate to 100mL/min, heating to 700 ℃ at 3 ℃/min, keeping for 2h, continuously heating to 800 ℃, changing water vapor, keeping for 30min, and naturally cooling to obtain the nitrogen-doped biochar ball carrier Al ₂ O ₃ -NC。

Catalyst Co/Al ₂ O ₃ Applications 1) to 6) of NC are as follows:

3-1) subjecting the unreduced Co/Al to the above-mentioned method ₂ O ₃ NC catalyst packingAnd quartz sand and 3mm porcelain balls are sequentially filled at two ends of a constant temperature zone of the fixed bed reactor for supporting. Setting the heating rate to 5 ℃/min, and setting the heating rate to 100mL/min H at 300 DEG C ₂ Reducing for 3h under the atmosphere. The temperature is kept unchanged, the reaction pressure is regulated to be 4MPa, the hydrogen flow is 30mL/min, the n-dodecane solution of guaiacol (the mass concentration of guaiacol is 10%) is pumped into a fixed bed reactor through a plunger metering pump, a sample is collected after the guaiacol is stabilized for 3 hours, and the composition analysis is carried out through a gas chromatography-mass spectrometer.

3-2) subjecting the unreduced Co/Al to the above-mentioned method ₂ O ₃ NC catalyst is filled into a constant temperature area of the fixed bed reactor, and quartz sand and 3mm porcelain balls are sequentially filled at two ends for supporting. Setting the heating rate to 5 ℃/min, and setting the heating rate to 100mL/min H at 300 DEG C ₂ Reducing for 3h under the atmosphere. The temperature is kept unchanged, the reaction pressure is regulated to be 2MPa, the hydrogen flow is 100mL/min, the n-dodecane solution of guaiacol (the mass concentration of guaiacol is 5%) is pumped into a fixed bed reactor through a plunger metering pump, a sample is collected after the guaiacol is stabilized for 3 hours, and the composition analysis is carried out through a gas chromatography-mass spectrometer.

3-3) subjecting the unreduced Co/Al to ₂ O ₃ NC catalyst is filled into a constant temperature area of the fixed bed reactor, and quartz sand and 3mm porcelain balls are sequentially filled at two ends for supporting. Setting the heating rate to 5 ℃/min, and setting the heating rate to 100mL/min H at 300 DEG C ₂ Reducing for 3h under the atmosphere. The temperature is kept unchanged, the reaction pressure is regulated to be 4MPa, the hydrogen flow is 100mL/min, the n-dodecane solution of guaiacol (the mass concentration of guaiacol is 5%) is pumped into a fixed bed reactor through a plunger metering pump, a sample is collected after the guaiacol is stabilized for 3 hours, and the composition analysis is carried out through a gas chromatography-mass spectrometer.

3-4) subjecting the unreduced Co/Al to ₂ O ₃ NC catalyst is filled into a constant temperature area of the fixed bed reactor, and quartz sand and 3mm porcelain balls are sequentially filled at two ends for supporting. Setting the heating rate to 5 ℃/min, and setting the temperature to be 300 ℃ and 100mL/min H ₂ Reducing for 3h under the atmosphere. The temperature is kept unchanged, the reaction pressure is regulated to be 2MPa, the hydrogen flow is 100mL/min, the n-dodecane solution of guaiacol (the mass concentration of guaiacol is 10%) is pumped into a fixed bed reactor through a plunger metering pump, and after the guaiacol is stabilized for 3h, the guaiacol is collectedSamples were collected and analyzed for composition using a gas chromatograph-mass spectrometer.

3-5) subjecting the unreduced Co/Al to ₂ O ₃ NC catalyst is filled into a constant temperature area of the fixed bed reactor, and quartz sand and 3mm porcelain balls are sequentially filled at two ends for supporting. Setting the heating rate to 5 ℃/min, and setting the temperature to be 300 ℃ and 100mL/min H ₂ Reducing for 3h under the atmosphere. The temperature is kept unchanged, the reaction pressure is regulated to be 4MPa, the hydrogen flow is 100mL/min, the n-dodecane solution of guaiacol (the mass concentration of guaiacol is 10%) is pumped into a fixed bed reactor through a plunger metering pump, a sample is collected after the guaiacol is stabilized for 3 hours, and the composition analysis is carried out through a gas chromatography-mass spectrometer.

3-6) subjecting the unreduced Co/Al to ₂ O ₃ NC catalyst is filled into a constant temperature area of the fixed bed reactor, and quartz sand and 3mm porcelain balls are sequentially filled at two ends for supporting. Setting the heating rate to 5 ℃/min, and setting the temperature to be 300 ℃ and 100mL/min H ₂ Reducing for 3h under the atmosphere. The temperature is kept unchanged, the reaction pressure is regulated to be 2MPa, the hydrogen flow is 30mL/min, the n-dodecane solution of guaiacol (the mass concentration of guaiacol is 10%) is pumped into a fixed bed reactor through a plunger metering pump, a sample is collected after the guaiacol is stabilized for 3 hours, and the composition analysis is carried out through a gas chromatography-mass spectrometer.

EXAMPLE 4Co-Fe/Al ₂ O ₃ Preparation and application of NC catalyst

Co-Fe/Al of the present example ₂ O ₃ -NC catalyst preparation comprising the steps of (as in fig. 1):

(1) - (3) as in example 1;

(4) 3.7g Co (NO) ₃ ) ₂ ·6H ₂ O and 2.7g Fe (NO) ₃ ) ₃ ·9H ₂ Adding O into 5mL of water, adding 7.5g of carbon sphere carrier after full dissolution, performing ultrasonic dispersion for 15min, and slowly evaporating water in a water bath environment at 50 ℃; drying the evaporated catalyst in an oven at 80 ℃ overnight, then roasting at a heating rate of 3 ℃/min, a roasting temperature of 500 ℃ and a holding time of 3 hours, naturally cooling and preserving to obtain unreduced Co-Fe/Al ₂ O ₃ NC catalyst (active component Co mass fraction 10%, fe mass fraction)5%).

Catalyst Co-Fe/Al ₂ O ₃ Applications 1) to 2) of NC are as follows:

4-1) Co-Fe/Al to be unreduced as described above ₂ O ₃ NC catalyst is filled into a constant temperature area of the fixed bed reactor, and quartz sand and 3mm porcelain balls are sequentially filled at two ends for supporting. Setting the heating rate to 5 ℃/min, and setting the temperature to be 300 ℃ and 100mL/min H ₂ Reducing for 3h under the atmosphere. The temperature is kept unchanged, the reaction pressure is regulated to be 4MPa, the hydrogen flow is 30mL/min, the n-dodecane solution of guaiacol (the mass concentration of guaiacol is 10%) is pumped into a fixed bed reactor through a plunger metering pump, a sample is collected after the guaiacol is stabilized for 3 hours, and the composition analysis is carried out through a gas chromatography-mass spectrometer.

4-2) Co-Fe/Al to be unreduced as described above ₂ O ₃ NC catalyst is filled into a constant temperature area of the fixed bed reactor, and quartz sand and 3mm porcelain balls are sequentially filled at two ends for supporting. Setting the heating rate to 5 ℃/min, and setting the temperature to be 300 ℃ and 100mL/min H ₂ Reducing for 3h under the atmosphere. The temperature is kept unchanged, the reaction pressure is regulated to be 2MPa, the hydrogen flow is 30mL/min, the n-dodecane solution of guaiacol (the mass concentration of guaiacol is 10%) is pumped into a fixed bed reactor through a plunger metering pump, a sample is collected after the guaiacol is stabilized for 3 hours, and the composition analysis is carried out through a gas chromatography-mass spectrometer.

EXAMPLE 5Ni-Co/Al ₂ O ₃ Preparation and application of NC catalyst

Ni-Co/Al of this example ₂ O ₃ -NC catalyst preparation comprising the steps of (as in fig. 1):

(1) - (3) as in example 1;

(4) 1.85g Co (NO) ₃ ) ₂ ·6H ₂ O and 1.85g Ni (NO) ₃ ) ₃ ·6H ₂ Adding O into 5mL of water, adding 7.5g of carbon sphere carrier after full dissolution, performing ultrasonic dispersion for 15min, and slowly evaporating water in a water bath environment at 50 ℃; drying the evaporated catalyst in an oven at 80 ℃ overnight, then roasting at a heating rate of 3 ℃/min, a roasting temperature of 500 ℃ and a holding time of 3 hours, naturally cooling and preserving to obtain unreduced Co-Ni/Al ₂ O ₃ NC catalysisThe catalyst (active component Co mass fraction is 5%, ni mass fraction is 5%).

Catalyst Co-Ni/Al ₂ O ₃ The application of NC is as follows:

the unreduced Co-Ni/Al is treated ₂ O ₃ NC catalyst is filled into a constant temperature area of the fixed bed reactor, and quartz sand and 3mm porcelain balls are sequentially filled at two ends for supporting. Setting the heating rate to 5 ℃/min, and setting the temperature to be 300 ℃ and 100mL/min H ₂ Reducing for 3h under the atmosphere. The temperature is kept unchanged, the reaction pressure is regulated to be 2MPa, the hydrogen flow is 30mL/min, the n-dodecane solution of guaiacol (the mass concentration of guaiacol is 10%) is pumped into a fixed bed reactor through a plunger metering pump, a sample is collected after the guaiacol is stabilized for 3 hours, and the composition analysis is carried out through a gas chromatography-mass spectrometer.

EXAMPLE 6Co/ZrO ₂ Preparation and application of NC catalyst

Co/ZrO of this example ₂ -NC catalyst preparation comprising the steps of (as in fig. 1):

(1) Waste poplar powder and ZrO are treated ₂ Uniformly mixing polyacrylonitrile with the mass ratio of 2:2:3, and adding an N, N-dimethylformamide solvent, wherein the mass fraction of the solvent is 82.5%; heating in 70deg.C water bath, and stirring with electric stirrer at 3000r/min for 3min to obtain suspension with uniform dispersion.

(2) Filling the suspension into a syringe, sleeving a needle with the inner diameter of 1.55mm, and placing the syringe on a syringe pump with constant-speed driving force; dropwise adding the suspension into an ethanol water solution (the mass concentration is 45%) by power, wherein the adding speed is 150mL/h, and the droplets are dropwise added into the ethanol water for instant solidification; after the dropping ball operation is finished, separating out the carbon-based ball precursor by a filtering mode, soaking the carbon-based ball precursor in pure water for 15min, and repeatedly washing for 8-10 times to replace redundant solvents in the pore canal in the ball cavity.

(3) After the carbon-based ball precursor is subjected to forced air heating and drying, placing the carbon-based ball precursor into a tube furnace, and introducing air with the flow rate of 60 mL/min; sequentially heating to 180 ℃ for 1h, 210 ℃ for 1h, 240 ℃ for 1h,260 ℃ for 1h, and 280 ℃ for 1.5 h; after cooling to room temperature, the flow rate of nitrogen is changed intoHeating to 700 ℃ at a speed of 3 ℃/min at 100mL/min, keeping for 2 hours, continuously heating to 800 ℃, introducing water vapor, keeping for 30 minutes, and naturally cooling to obtain the nitrogen-doped biochar ball carrier ZrO ₂ -NC。

(4) 3.7g Co (NO) ₃ ) ₂ ·6H ₂ Adding O into 5mL of water, adding 7.5g of carbon sphere carrier after full dissolution, performing ultrasonic dispersion for 15min, and slowly evaporating water in a water bath environment at 50 ℃; drying the evaporated catalyst in an oven at 80 ℃ overnight, then roasting at a heating rate of 3 ℃/min, a roasting temperature of 500 ℃ and a holding time of 3 hours, naturally cooling and preserving to obtain unreduced Co/ZrO ₂ NC catalyst (active component Co mass fraction 10%).

Catalyst Co/ZrO ₂ The application of NC is as follows:

the unreduced Co/ZrO ₂ NC catalyst is filled into a constant temperature area of the fixed bed reactor, and quartz sand and 3mm porcelain balls are sequentially filled at two ends for supporting. Setting the heating rate to 5 ℃/min, and setting the heating rate to 100mL/min H at 300 DEG C ₂ Reducing for 3h under the atmosphere. The temperature is kept unchanged, the reaction pressure is regulated to be 2MPa, the hydrogen flow is 30mL/min, the n-dodecane solution of guaiacol (the mass concentration of guaiacol is 10%) is pumped into a fixed bed reactor through a plunger metering pump, a sample is collected after the guaiacol is stabilized for 3 hours, and the composition analysis is carried out through a gas chromatography-mass spectrometer.

EXAMPLE 7Ni/Nb ₂ O ₅ Preparation and application of NC catalyst

Ni/Nb of this example ₂ O ₅ -NC catalyst preparation comprising the steps of (as in fig. 1):

(1) Waste poplar powder and Nb ₂ O ₅ Uniformly mixing polyacrylonitrile with the mass ratio of 1:2:4, and adding an N, N-dimethylformamide solvent, wherein the mass fraction of the solvent is 82.5%; heating in 70deg.C water bath, and stirring with electric stirrer at 3000r/min for 3min to obtain suspension with uniform dispersion.

(3) After the carbon-based ball precursor is subjected to forced air heating and drying, placing the carbon-based ball precursor into a tube furnace, and introducing air with the flow rate of 60 mL/min; sequentially heating to 180 ℃ for 1h, 210 ℃ for 1h, 240 ℃ for 1h,260 ℃ for 1h, and 280 ℃ for 1.5 h; cooling to room temperature, changing nitrogen flow rate to 100mL/min, heating to 700 ℃ at 3 ℃/min, keeping for 2h, continuously heating to 900 ℃, changing water vapor, keeping for 30min, and naturally cooling to obtain the nitrogen-doped biochar ball carrier Nb ₂ O ₅ -NC。

(4) 3.7g of Ni (NO) ₃ ) ₂ ·6H ₂ Adding O into 5mL of water, adding 7.5g of carbon sphere carrier after full dissolution, performing ultrasonic dispersion for 15min, and slowly evaporating water in a water bath environment at 50 ℃; drying the evaporated catalyst in an oven at 80 ℃ overnight, then roasting at a heating rate of 3 ℃/min, a roasting temperature of 500 ℃ and a holding time of 3 hours, naturally cooling and preserving to obtain unreduced Ni/ZrO ₂ NC catalyst (active component Ni mass fraction 10%).

Catalyst Ni/Nb ₂ O ₅ The application of NC is as follows:

the unreduced Ni/ZrO ₂ NC catalyst is filled into a constant temperature area of the fixed bed reactor, and quartz sand and 3mm porcelain balls are sequentially filled at two ends for supporting. Setting the heating rate to 5 ℃/min, and setting the temperature to be 300 ℃ and 100mL/min H ₂ Reducing for 3h under the atmosphere. The temperature is kept unchanged, the reaction pressure is regulated to be 4MPa, the hydrogen flow rate is 30mL/min, the n-dodecane solution of guaiacol (the mass concentration of guaiacol is 10%) is pumped into a fixed bed reactor through a plunger metering pump, a sample is collected after the guaiacol is stabilized for 3 hours, and the composition analysis is carried out through a gas chromatography-mass spectrometer.

EXAMPLE 8Ni/SiO ₂ Preparation and application of NC catalyst

Ni/SiO of this example ₂ -NC catalyst preparation comprising the steps of (as in fig. 1):

(1) Waste corn stalk powder and SiO ₂ Uniformly mixing polyacrylonitrile with the mass ratio of 2:2:3, and adding a dimethylacetamide solvent with the mass fraction of 82.5%; heating in 70deg.C water bath, and stirring with electric stirrer at 3000r/min for 3min to obtain suspension with uniform dispersion.

(2) Filling the suspension into a syringe, sleeving a needle with the inner diameter of 2.0mm, and placing the syringe on a syringe pump with constant-speed driving force; dropwise adding the suspension into an ethanol water solution (the mass concentration is 45%) by power, wherein the adding speed is 150mL/h, and the droplets are dropwise added into the ethanol water for instant solidification; after the dropping ball operation is finished, separating a carbon-based ball precursor by a filtering mode, soaking the carbon-based ball precursor in pure water for 15min, and repeatedly washing for 8 times to replace redundant solvents in the pore canal in the ball cavity;

(3) After the carbon-based ball precursor is subjected to forced air heating and drying, placing the carbon-based ball precursor into a tube furnace, and introducing air with the flow rate of 60 mL/min; sequentially heating to 180 ℃ for 1h, 210 ℃ for 1h, 240 ℃ for 1h,260 ℃ for 1h, and 280 ℃ for 1.5 h; cooling to room temperature, changing nitrogen flow rate to 100mL/min, heating to 700 ℃ at 3 ℃/min, keeping for 2h, continuously heating to 800 ℃, changing water vapor, keeping for 45min, and naturally cooling to obtain the nitrogen-doped biochar ball carrier SiO ₂ -NC。

(4) 3.7g of Ni (NO) ₃ ) ₂ ·6H ₂ Adding O into 5mL of water, adding 7.5g of carbon sphere carrier after full dissolution, performing ultrasonic dispersion for 15min, and slowly evaporating water in a water bath environment at 50 ℃; drying the evaporated catalyst in an oven at 80 ℃ overnight, then roasting at a heating rate of 3 ℃/min, a roasting temperature of 500 ℃ and a holding time of 3 hours, naturally cooling and preserving to obtain unreduced Ni/SiO ₂ NC catalyst (active component Ni mass fraction 10%).

Catalyst Ni/SiO ₂ The application of NC is as follows:

the unreduced Ni/SiO is treated ₂ NC catalyst packingAnd (3) feeding the mixture into a constant temperature area of the fixed bed reactor, and sequentially filling quartz sand and 3mm porcelain balls at two ends of the mixture for supporting. Setting the heating rate to 5 ℃/min, and setting the temperature to be 300 ℃ and 100mL/min H ₂ Reducing for 3h under the atmosphere. The temperature is kept unchanged, the reaction pressure is regulated to be 2MPa, the hydrogen flow is 30mL/min, the n-dodecane solution of guaiacol (the mass concentration of guaiacol is 10%) is pumped into a fixed bed reactor through a plunger metering pump, a sample is collected after the guaiacol is stabilized for 3 hours, and the composition analysis is carried out through a gas chromatography-mass spectrometer.

EXAMPLE 9Ni/TiO ₂ Preparation and application of NC catalyst

Ni/TiO of this example ₂ -NC catalyst preparation comprising the steps of (as in fig. 1):

(1) Waste corn stalk powder and TiO ₂ Uniformly mixing polyacrylonitrile with the mass ratio of 4:1:2, and adding a dimethylacetamide solvent with the mass fraction of 82.5%; heating in 70deg.C water bath, and stirring with electric stirrer at 3000r/min for 3min to obtain suspension with uniform dispersion.

(2) Filling the suspension into a syringe, sleeving a needle with the inner diameter of 2.0mm, and placing the syringe on a syringe pump with constant-speed driving force; dropwise adding the suspension into an ethanol water solution (the mass concentration is 45%) by power, wherein the adding speed is 150mL/h, and the droplets are dropwise added into the ethanol water for instant solidification; after the dropping ball operation is finished, separating out the carbon-based ball precursor by a filtering mode, soaking the carbon-based ball precursor in pure water for 15min, and repeatedly washing for 8 times to replace redundant solvents in the pore canal in the ball cavity.

(3) After the carbon-based ball precursor is subjected to forced air heating and drying, placing the carbon-based ball precursor into a tube furnace, and introducing air with the flow rate of 60 mL/min; sequentially heating to 180 ℃ for 1h, 210 ℃ for 1h, 240 ℃ for 1h,260 ℃ for 1h, and 280 ℃ for 1.5 h; cooling to room temperature, changing the flow rate of nitrogen into 100mL/min, heating to 700 ℃ at 3 ℃/min, keeping for 2 hours, continuously heating to 900 ℃, changing the flow rate of nitrogen into water vapor, keeping for 1 hour, and naturally cooling to obtain the nitrogen-doped biochar ball carrier TiO ₂ -NC。

(4) 3.7g of Ni (NO) ₃ ) ₂ ·6H ₂ O additionAdding 7.5g of carbon sphere carrier into 5mL of water after the carbon sphere carrier is fully dissolved, performing ultrasonic dispersion for 15min, and slowly evaporating the water in a water bath environment at 50 ℃; drying the evaporated catalyst in an oven at 80 ℃ overnight, then roasting at a heating rate of 3 ℃/min, a roasting temperature of 500 ℃ and a holding time of 3 hours, naturally cooling and preserving to obtain unreduced Ni/TiO ₂ NC catalyst (active component Co mass fraction 10%).

Catalyst Ni/TiO ₂ The application of NC is as follows:

the unreduced Ni/TiO is treated with ₂ NC catalyst is filled into a constant temperature area of the fixed bed reactor, and quartz sand and 3mm porcelain balls are sequentially filled at two ends for supporting. Setting the heating rate to 5 ℃/min, and setting the temperature to be 300 ℃ and 100mL/min H ₂ Reducing for 3h under the atmosphere. The temperature is kept unchanged, the reaction pressure is regulated to be 4MPa, the hydrogen flow is 30mL/min, the n-dodecane solution of guaiacol (the mass concentration of guaiacol is 10%) is pumped into a fixed bed reactor through a plunger metering pump, a sample is collected after the guaiacol is stabilized for 3 hours, and the composition analysis is carried out through a gas chromatography-mass spectrometer.

EXAMPLE 10Co/Al ₂ O ₃ Preparation and application of NC catalyst

(1) Waste walnut shell powder and Al ₂ O ₃ Uniformly mixing polyacrylonitrile with the mass ratio of 3:1:3, and adding a dimethylacetamide solvent with the mass fraction of 82.5%; heating in 70deg.C water bath, and stirring with electric stirrer at 3000r/min for 3min to obtain suspension with uniform dispersion.

(4) 0.74g Co (NO) ₃ ) ₂ ·6H ₂ Adding O into 5mL of water, adding 7.5g of carbon sphere carrier after full dissolution, performing ultrasonic dispersion for 15min, and slowly evaporating water in a water bath environment at 50 ℃; drying the evaporated catalyst in an oven at 80 ℃ overnight, then roasting at a heating rate of 3 ℃/min, a roasting temperature of 500 ℃ and a holding time of 3 hours,

naturally cooling and preserving to obtain unreduced Co/Al ₂ O ₃ NC catalyst (active component Co mass fraction 2%).

Catalyst Co/Al ₂ O ₃ The application of NC is as follows:

the unreduced Co/Al is obtained by the preparation ₂ O ₃ NC catalyst is filled into a constant temperature area of the fixed bed reactor, and quartz sand and 3mm porcelain balls are sequentially filled at two ends for supporting. Setting the heating rate to 5 ℃/min, and setting the temperature to be 450 ℃ and 100mL/min H ₂ Mixed with Ar atmosphere (H) ₂ The volume ratio is 5 percent) for 1 hour. Adjusting the temperature to 300 ℃, adjusting the reaction pressure to 2MPa, converting gas into hydrogen, enabling the flow rate to be 100mL/min, pumping an n-dodecane solution of guaiacol (the mass concentration of guaiacol is 5%) into a fixed bed reactor through a plunger metering pump, collecting a sample after stabilizing for 3 hours, and carrying out composition analysis through a gas chromatography-mass spectrometer.

Example 11

(1) Waste walnut shell powder and Al ₂ O ₃ And polyacrylonitrile in terms of massUniformly mixing the components according to the ratio of 3.6:0.4:3, and adding a dimethylacetamide solvent, wherein the mass fraction of the solvent is 82.5%; heating in 70deg.C water bath, and stirring with electric stirrer at 3000r/min for 3min to obtain suspension with uniform dispersion.

Catalyst Co/Al ₂ O ₃ The application of NC is as follows:

the unreduced Co/Al is obtained by the preparation ₂ O ₃ NC catalyst is filled into a constant temperature area of the fixed bed reactor, and quartz sand and 3mm porcelain balls are sequentially filled at two ends for supporting. Setting the heating rate to 5 ℃/min, and setting the temperature to be 450 ℃ and 100mL/min H ₂ Mixed with Ar atmosphere (H) ₂ The volume ratio is 5 percent) for 1 hour. Adjusting the temperature to 300 ℃, adjusting the reaction pressure to 2MPa, converting the gas into hydrogen with the flow rate of 100mL/min, pumping an n-dodecane solution of guaiacol (the mass concentration of guaiacol is 5%) into a fixed bed reactor through a plunger metering pump, collecting a sample after stabilizing for 3h, and carrying out composition analysis through a gas chromatography-mass spectrometer.

Comparative example 1Co/NC catalyst preparation and use

The preparation of the Co/NC catalyst in this comparative example comprises the following steps:

(1) Uniformly mixing waste walnut shell powder and polyacrylonitrile according to a mass ratio of 4:3, and adding an N, N-dimethylformamide solvent, wherein the mass fraction of the solvent is 82.5%; heating in 70deg.C water bath, and stirring with electric stirrer at 3000r/min for 3min to obtain suspension with uniform dispersion.

(2) Filling the suspension into a syringe, sleeving a needle with the inner diameter of 1.55mm, and placing the syringe on a syringe pump with constant-speed driving force; dropwise adding the suspension into an ethanol water solution (the mass concentration is 45%) by power, wherein the adding speed is 150mL/h, and the droplets are dropwise added into the ethanol water for instant solidification; after the dropping ball operation is finished, separating a carbon-based ball precursor by a filtering mode, soaking the carbon-based ball precursor in pure water for 15min, and repeatedly washing for 8 times to replace redundant solvents in the pore canal in the ball cavity;

(3) After the carbon-based ball precursor is subjected to forced air heating and drying, placing the carbon-based ball precursor into a tube furnace, and introducing air with the flow rate of 60 mL/min; sequentially heating to 180 ℃ for 1h, 210 ℃ for 1h, 240 ℃ for 1h,260 ℃ for 1h, and 280 ℃ for 1.5 h; cooling to room temperature, changing the flow rate of nitrogen into 100mL/min, heating to 700 ℃ at 3 ℃/min, keeping for 2 hours, continuously heating to 850 ℃, changing the flow rate of nitrogen into water vapor, keeping for 1 hour, and naturally cooling to obtain the nitrogen-doped biochar ball carrier NC;

(4) As in example 1.

The application of the catalyst Co/NC is as follows:

by combining the unreduced Co/NAnd C, filling the catalyst into a constant temperature area of the fixed bed reactor, and sequentially filling quartz sand and 3mm ceramic balls at two ends for supporting. Setting the heating rate to 5 ℃/min, and setting the heating rate to 100mL/min H at 300 DEG C ₂ Reducing for 3h under the atmosphere. The temperature is kept unchanged, the reaction pressure is regulated to be 2MPa, the flow rate of hydrogen gas flow is 30mL/min, the n-dodecane solution of guaiacol (the mass concentration of guaiacol is 10%) is pumped into a fixed bed reactor through a plunger metering pump, and after the guaiacol is stabilized for 3 hours, a sample is collected and subjected to composition analysis through a gas chromatography-mass spectrometer.

Comparative example 2Co/NC catalyst preparation and use

(1) Uniformly mixing waste walnut shell powder and polyacrylonitrile in a mass ratio of 2:5, and adding an N, N-dimethylformamide solvent, wherein the mass fraction of the solvent is 82.5%; heating in 70deg.C water bath, and stirring with electric stirrer at 3000r/min for 3min to obtain suspension with uniform dispersion.

(2) Filling the suspension into a syringe, sleeving a needle with the inner diameter of 1.0mm, and placing the syringe on a syringe pump with constant-speed driving force; dropwise adding the suspension into an ethanol water solution (the mass concentration is 45%) by power, wherein the adding speed is 150mL/h, and the droplets are dropwise added into the ethanol water for instant solidification; after the dropping ball operation is finished, separating a carbon-based ball precursor by a filtering mode, soaking the carbon-based ball precursor in pure water for 15min by ultrasonic waves, and repeatedly washing for 10 times to replace redundant solvents in the pore canal in the ball cavity;

(4) As in example 1.

The application of the catalyst Co/NC is as follows:

and filling the unreduced Co/NC catalyst into a constant temperature area of a fixed bed reactor, and sequentially filling quartz sand and 3mm porcelain balls at two ends for supporting. Setting the heating rate to 5 ℃/min, and setting the heating rate to 100mL/min H at 300 DEG C ₂ Reducing for 3h under the atmosphere. The temperature is kept unchanged, the reaction pressure is regulated to be 4MPa, the hydrogen flow is 30mL/min, the n-dodecane solution of guaiacol (the mass concentration of guaiacol is 10%) is pumped into a fixed bed reactor through a plunger metering pump, a sample is collected after the guaiacol is stabilized for 3 hours, and the composition analysis is carried out through a gas chromatography-mass spectrometer.

Comparative example 3Co/NC catalyst preparation and use

(1) Dissolving polyacrylonitrile in an N, N-dimethylformamide solvent, wherein the mass fraction of the solvent is 82.5%; heating in 70deg.C water bath, and stirring with electric stirrer at 3000r/min for 3min to obtain suspension with uniform dispersion.

(2) Filling the suspension into a syringe, sleeving a needle with the inner diameter of 1.0mm, and placing the syringe on a syringe pump with constant-speed driving force; dropwise adding the suspension into an ethanol water solution (the mass concentration is 45%) by power, wherein the adding speed is 150mL/h, and the droplets are dropwise added into the ethanol water for instant solidification; after the dropping ball operation is finished, separating a carbon-based ball precursor by a filtering mode, soaking the carbon-based ball precursor in pure water for 15min, and repeatedly washing for 8 times to replace redundant solvents in the pore canal in the ball cavity;

(3) After the carbon-based ball precursor is subjected to forced air heating and drying, placing the carbon-based ball precursor into a tube furnace, and introducing air with the flow rate of 60 mL/min; step-type temperature programming oxidation reaction is carried out by sequentially increasing the temperature to 180 ℃ for 1h, 210 ℃ for 1h, 240 ℃ for 1h,260 ℃ for 1h and 280 ℃ for 1.5 h; changing the flow rate of nitrogen into 100mL/min after cooling, heating to 700 ℃ at 3 ℃/min, keeping for 2 hours, continuously heating to 850 ℃, changing the flow rate of water vapor, keeping for 1 hour, and naturally cooling to obtain a carbon sphere carrier NC;

(4) As in example 1.

Application of Co/NC catalyst preparation

The unreduced Co-N is treatedAnd C, filling the catalyst into a constant temperature area of the fixed bed reactor, and sequentially filling quartz sand and 3mm ceramic balls at two ends for supporting. Setting the heating rate to 5 ℃/min, and setting the temperature at 300 ℃ and H ₂ Reducing for 3h under the atmosphere. The temperature is kept unchanged, the reaction pressure is regulated to be 2MPa, the hydrogen flow is 30mL/min, the n-dodecane solution of guaiacol (the mass concentration of guaiacol is 10%) is pumped into a fixed bed reactor through a plunger metering pump, a sample is collected after the guaiacol is stabilized for 3 hours, and the composition analysis is carried out through a gas chromatography-mass spectrometer.

The catalysts prepared in examples 1 to 9 and comparative examples 1 to 3 were subjected to elemental analysis, XPS characterization and BET characterization, and the results obtained are shown in Table 1.

Table 1 catalyst support compositions and properties of examples 1 to 9, and comparative examples 1 to 3

As is clear from Table 1, when the spherical particle size of the nitrogen-doped biochar-based bio-oil upgrading catalyst is 0.5 to 2.0mm, the specific surface area is 200 to 1000m ² Per gram, the total pore volume is 0.20-0.80 cm ³ And/g, wherein the nitrogen-doped biochar-based bio-oil upgrading catalyst is internally provided with a gradient pore channel structure with micropores, mesopores and macropores distributed. The doping content of nitrogen element is 4.0-12.0%.

TABLE 2 Properties of the catalyst prepared according to the invention in hydrodeoxygenation reactions

Note that: the C5-C7 alkane comprises cyclohexane.

In table 2, the guaiacol conversion rate was calculated as:

as shown in Table 2, the invention also provides the nitrogen-doped biochar ball catalyst for hydrodeoxygenation of the catalytic guaiacol, the conversion rate of the catalytic guaiacol is up to 100%, the deoxidization rate reaches 96.7%, the main product is cyclohexane, the selectivity is up to 90%, the conversion rate of the catalytic guaiacol is still stable at 99.4% after the catalyst is continuously reacted for 45 hours, and the deoxidization rate of the product is 80%.

Circulation experiment

Catalyst Co/Al provided in example 2 ₂ O ₃ In the application test of NC, after continuous operation for 45 hours under the reaction condition of 300 ℃ and 2MPa, the guaiacol conversion rate is still stable at 99.4%, and the product deoxidization rate is maintained at 80%. The catalyst prepared by the method has high activity, is a very stable supported catalyst, has long service life, reduces the cost of the catalyst, and has good application value in actual production.

While embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the invention.

Claims

1. A nitrogen-doped biochar-based bio-oil upgrading catalyst is characterized in that: taking nitrogen-doped biochar as a carrier, and taking one or more than two metals in a VIII group as active components, wherein the active components are loaded on the carrier; the carrier is composed of biomass, polyacrylonitrile and M _x O _y Is prepared into the biomass powder, M _x O _y And the mass ratio of the polyacrylonitrile is (2-4) (0.4-2) (2-4); the M is _x O _y Wherein M is a group IIIAOne element in IVA, IVB, VB, VIB or VIIB, x is 1-2, and y is 2-5; the mass fraction of the active component loaded on the carrier is 2-15%.

2. The nitrogen-doped biochar-based bio-oil upgrading catalyst according to claim 1, wherein the nitrogen-doped biochar-based bio-oil upgrading catalyst is in the form of spherical particles having a size of 0.5 to 2.0 mm and a specific surface area of 200 to 1000m ² Per gram, the total pore volume is 0.20 to 0.80 and 0.80 cm ³ And/g, the compressive strength of the single-particle catalyst is not less than 22N/particle.

3. The nitrogen-doped biochar-based bio-oil upgrading catalyst according to claim 1, wherein the nitrogen-doped biochar-based bio-oil upgrading catalyst has a nitrogen element doping content of 4.0 to 12.0%.

4. The nitrogen-doped biochar-based bio-oil upgrading catalyst according to claim 1, wherein the biomass in the carrier is at least one of fruit shells, woody and straw; the M is _x O _y Is Al ₂ O ₃ 、ZrO ₂ 、Nb ₂ O ₅ 、SiO ₂ 、TiO ₂ 、CeO ₂ At least one of them.

5. A method for preparing a nitrogen-doped biochar-based bio-oil upgrading catalyst according to any one of claims 1 to 4, comprising the steps of:

step 1, preparing a suspension: biomass powder, M _x O _y Uniformly mixing with polyacrylonitrile, then adding a polar organic solvent, heating and stirring to obtain a uniformly distributed suspension;

step 2, preparing a nitrogen-doped biochar ball precursor: filling the suspension liquid which is uniformly distributed in the step 1 into an injection tube, and performing ball dripping operation on the injection tube into the ethanol aqueous solution of the coagulating bath by using a uniform-speed driving force to obtain a carbon-based ball precursor;

step 3, charcoal Ball precursor drying, oxidation, carbonization and activation: repeatedly ultrasonic soaking and washing the carbon-based ball precursor in the step 2 with water, and drying, oxidizing, carbonizing and activating to obtain M _x O _y -NC carbon sphere particle carriers;

6. The method for preparing nitrogen-doped biochar-based bio-oil upgrading catalyst according to claim 5, wherein in step 1, the biomass powder, M _x O _y The mixing mass ratio of the polyacrylonitrile to the polyacrylonitrile is (2-4) (0.4-2) (2-4); the polar organic solvent is at least one of N, N-dimethylformamide, dimethylacetamide and N-methylpyrrolidone, and the heating temperature is 60-80 ℃.

7. The method for preparing the nitrogen-doped biochar-based bio-oil upgrading catalyst according to claim 5, wherein in the step 2, the inner diameter of a needle head of the injection tube is 1.00-2.0 mm, and the constant-speed pushing rate of the injection tube is controlled to be 120-180 mL/h; the mass concentration of the coagulating bath ethanol water solution is 25-45%.

8. The method for preparing the nitrogen-doped biochar-based bio-oil upgrading catalyst according to claim 5, wherein in the step 3, the oxidation is carried out at a gradient temperature rise and heating between 180 ℃ and 290 ℃, the air flow is 50-60 mL/min, and the temperature rise rate is 1-5 ℃/min; carbonization and activation are continuous processes, the heating rate is 1-10 ℃/min, the nitrogen flow is 100-300 mL/min, and the carbonization temperature is 550-750 ℃; the activation temperature is 800-900 ℃.

9. The method for preparing a nitrogen-doped biochar-based bio-oil upgrading catalyst according to claim 5, wherein in step 4, the active component is derived from a metal salt solution; the temperature rise rate of the roasting is 1-10 ℃/min, and the roasting temperature is 450-550 ℃; the reduction temperature is 300-450 ℃, the heating rate is 1-10 ℃/min, and the reduction gas is one of hydrogen gas or hydrogen-argon mixed gas.

10. The use of a nitrogen-doped biochar-based bio-oil upgrading catalyst according to any one of claims 1 to 4 for the hydroprocessing of biomass pyrolysis liquids to liquid hydrocarbon fuels.

11. The use of the nitrogen-doped biochar-based bio-oil upgrading catalyst according to claim 10, wherein guaiacol is used as a bio-oil model, and the mass space velocity of the reaction for hydrogenation upgrading of the fixed bed reactor to produce liquid hydrocarbon fuel is 0.5-1.0 h ^-1 Hydrogen volume/raw material volume=600-900L/L, reaction pressure is 2-4 MPa, and the liquid hydrocarbon fuel is mainly cyclohexane.