Method for synthesizing hydrocarbon fuel by catalyzing sulfur-containing biomass derivative through three metals

Abstract

The invention relates to a method for producing renewable fuel, in particular to a method for synthesizing hydrocarbon fuel by catalyzing sulfur-containing biomass derivatives through three metals. The invention discloses a process for converting oxygen-containing compounds derived from sulfur-containing and nitrogen-containing biomass into hydrocarbons through a catalytic technology, and relates to the field of green chemistry and biofuel production. The preparation method comprises the following steps: S1, pretreating raw materials; s2, filling a catalyst; s3, hydrogenation catalytic reaction; s4, sampling and detecting; and S5, separating and purifying a product. The combination of the three metals has a synergistic effect, can bring about optimization of an electronic effect and a geometric effect, can provide higher catalytic activity and selectivity in hydrogenation reaction, and compared with a traditional single-metal or double-metal catalyst, the three-metal catalyst can realize the same or even higher reaction rate and yield at lower temperature and pressure, and can be used for preparing the catalyst. The reaction energy consumption and the equipment requirement are reduced, and the economic benefit and the process feasibility are improved.

Description

Technical Field

[0001] The present invention relates to a method for producing renewable fuels, in particular to a method for synthesizing hydrocarbon fuels from sulfur-containing biomass derivatives using trimetallic catalysts. The present invention uses catalytic technology to convert oxygen-containing compounds derived from sulfur-containing and nitrogen-containing biomass into hydrocarbons, and relates to the fields of green chemistry and biofuel production. Background Art

[0002] As the global demand for environmental protection and reducing carbon emissions continues to increase, the development of renewable fuel technology has become a research hotspot. In existing technologies, the production and use of traditional petroleum-based fuels will lead to large amounts of greenhouse gas emissions, exacerbating climate change. In recent years, biomass-derived raw materials, such as vegetable oils and waste oils, can be used to prepare fuels through hydrogenation (such as the HEFA route), but they face problems such as low production efficiency and harsh process conditions. During the entire processing process, multiple steps of reactions are required, such as hydrogenation, deoxygenation, desulfurization and denitrification. The process is cumbersome, inefficient and energy-intensive. Therefore, how to efficiently convert oxygenated compounds into fuels under mild conditions has become a key issue. Summary of the invention

[0003] The present invention aims at the defects of the prior art mentioned in the background technology, and provides a method for synthesizing hydrocarbon fuels from sulfur-containing biomass derivatives catalyzed by trimetallic catalysts. The present invention uses a specific catalytic system to efficiently convert biomass-derived sulfur-containing and oxygen-containing compounds into hydrocarbons under mild conditions for use in renewable fuel production.

[0004] To achieve the above technical purpose, the technical solution adopted by the present invention is: a method for synthesizing hydrocarbon fuels by using trimetallic catalyzed sulfur-containing biomass derivatives, which is carried out according to the following steps: S1 Raw material pretreatment: remove impurities and moisture from the raw materials by filtering and preheating; S2 Catalyst loading: uniformly loading the trimetallic catalyst into the fixed bed reactor; S3 hydrogenation catalytic reaction: control the reaction temperature in the fixed bed reactor at 250-300°C, maintain the reaction pressure at 2-5 MPa; input hydrogen, the molar ratio of hydrogen to raw material is 2:1-5:1; S4 Sampling and testing: Regular sampling for product analysis, using gas chromatography to monitor substrate consumption and product formation; S5 Product separation and purification: Liquid products are obtained through condensation and separation of the water phase; the liquid products are distilled to separate the desired hydrocarbons.

[0005] In step S2, the tri-metal catalyst includes metal components of nickel, cobalt, molybdenum and a carrier of aluminum oxide.

[0006] The preparation steps of trimetallic catalyst are as follows: (1) calcining the carrier at 500-600°C in air for 2-4 hours; (2) dissolving soluble metal salts of nickel, cobalt and molybdenum in deionized water to form a metal precursor solution of a certain concentration; (3) Immerse the support in the metal precursor solution and stir at room temperature for 12-15 hours; (4) drying the impregnated support at 100-120° C. for 6-12 hours; and then calcining at 400-500° C. for 2-4 hours to reduce the metal precursor and attach it to the support to form metal nanoparticles; (5) The catalyst produced in step (4) is subjected to reduction treatment in hydrogen at 300-400° C. for 2-3 hours to finally form a trimetallic catalyst.

[0007] In the metal precursor solution, the concentration ratio of soluble nickel, cobalt and molybdenum metal salts dissolved in deionized water is 0.1-0.5M: 0.1-0.5M: 0.1-0.5M.

[0008] The trimetallic catalyst can be regenerated and the regeneration process is as follows: (1) Regeneration method: Regeneration is performed at 500°C in a hydrogen environment to remove carbon deposits and pollutants on the catalyst surface and restore catalyst activity; (2) Regeneration cycle: Regeneration is performed every 20-50 reaction cycles.

[0009] The amount of the trimetallic catalyst used in the fixed bed reactor is 0.5-2wt%.

[0010] In step S3, the time of the hydrogenation catalytic reaction is 2-6 hours.

[0011] Compared with the prior art, the technical advantage of the present invention is that it can achieve efficient hydrodeoxygenation, desulfurization and denitrification under milder process conditions, saving pretreatment such as desulfurization and denitrification of raw materials, reducing energy consumption, and the produced hydrocarbons can be used in high-quality renewable fuels.

[0012] The combination of three metals has a synergistic effect, which can optimize the electronic effect and geometric effect, and can provide higher catalytic activity and selectivity in hydrogenation reactions. Compared with single metal catalysts and bimetallic systems, trimetallic catalysts have multifunctional sites on their surfaces, which can carry out multi-step reactions (such as hydrogenation, deoxygenation, desulfurization and denitrogenation) in one step, reducing intermediates and side reactions. This multifunctionality helps to achieve single-step efficient conversion and simplify the process flow. Trimetallic catalysts show higher thermal stability under high temperature reaction conditions, and the metal (molybdenum) with anti-poisoning function in the metal combination can significantly reduce the deactivation rate of the catalyst and extend the catalyst life. Compared with traditional single metal or bimetallic catalysts, trimetallic catalysts can achieve the same or even higher reaction rate and yield at lower temperature and pressure, reduce the energy consumption and equipment requirements of the reaction, and improve the economic benefits and process feasibility. These advantages give trimetallic catalysts significant advantages in the conversion of biomass into sustainable liquid fuel production. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0014] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0015] The invention converts oxygen-containing compounds derived from sulfur-containing and nitrogen-containing biomass into hydrocarbons through catalytic technology.

[0016] The catalyst used in the present invention is a trimetallic catalyst with excellent hydrodeoxygenation, desulfurization and denitrification activities. The catalyst is composed of metal components (nickel (Ni), cobalt (Co), molybdenum (Mo)) and a carrier (Al2O3), which can efficiently catalyze biomass-derived oxygen-containing compounds under mild conditions. Alumina is used as the catalyst carrier because it has a high specific surface area and good thermal stability. The preparation method of the trimetallic catalyst is as follows: (1) Calcine the carrier at 500-600°C for 2-4 hours in air to remove impurities and surface moisture and improve surface activity; use alumina as the catalyst carrier because it has a high specific surface area and good thermal stability; (2) Dissolving soluble metal salts of nickel (Ni), cobalt (Co), and molybdenum (Mo) in deionized water to form a metal precursor solution of a certain concentration (0.1-0.5 M); the concentration ratio is 0.1-0.5M: 0.1-0.5M: 0.1-0.5M.

[0017] (3) Immerse the support in the metal precursor solution and stir at room temperature for 12 hours to ensure that the metal ions are evenly distributed on the support surface; (4) drying the impregnated support at 100-120° C. for 6-12 hours, and then calcining in air at 400-500° C. for 2-4 hours to reduce the metal precursor and attach it to the support to form metal nanoparticles; (5) The catalyst is reduced in hydrogen at 300-400°C for 2-3 hours to further activate the metal particles and improve their catalytic performance, ultimately forming a trimetallic catalyst.

[0018] Ni-Co-Mo (trimetallic catalyst) shows good performance in oil refining processes such as hydrodesulfurization and denitrogenation. Nickel (Ni) and cobalt (Co) provide good hydrogenation capacity, and molybdenum (Mo) enhances the stability of the catalyst under high sulfur and high nitrogen conditions and promotes the removal of oxygen, nitrogen and sulfur.

[0019] The specific process steps for synthesizing hydrocarbon fuels from sulfur-containing biomass derivatives using the above catalyst are as follows.

[0020] S1 Raw material pretreatment: The raw materials are oxygenated compounds derived from biomass, such as vegetable oil, waste oil or long-chain fatty acids. The raw materials are filtered and preheated (preheating temperature 80-120°C) to remove impurities and moisture to ensure the purity of the raw materials entering the reactor.

[0021] S2 catalyst loading: The prepared catalyst is uniformly loaded into the fixed bed reactor.

[0022] S3 hydrogenation reaction: Fixed bed reactor is suitable for continuous flow operation. The reaction temperature is precisely adjusted at 250-300°C by a thermostatic control device, and the reaction pressure is maintained at 2-5 MPa. The input amount of hydrogen is adjusted by a flow controller, and the molar ratio of high-purity hydrogen to substrate is 2:1 to 5:1.

[0023] Reaction temperature at 250-300°C: The reaction temperature needs to be high enough to promote hydrodeoxygenation and other conversion reactions, but should not be too high to avoid by-product formation and catalyst deactivation. For biomass-derived oxygenates, such as fatty acids and esters, the typical reaction temperature is 300-350°C. By using a trimetallic catalyst, the reaction temperature is 250-300°C, which is lower than that of traditional monometallic or bimetallic catalysts, reducing energy consumption.

[0024] Reaction pressure is 2-5 MPa: Hydrodeoxygenation reactions are usually carried out at medium to high pressures to ensure the solubility and reaction rate of hydrogen. The design of the trimetallic catalyst improves the adsorption and activation of hydrogen through synergistic effects, so that high catalytic performance can still be maintained under lower pressure conditions, which helps to achieve efficient conversion at relatively low pressures.

[0025] Hydrogen to substrate molar ratio (2:1 to 5:1): Excess hydrogen helps maintain the hydrogenation of the reaction and prevents coke formation. In the trimetallic system, the synergistic effect between the metals makes the activation and transfer of hydrogen more efficient, thereby reducing the excess demand for hydrogen and improving the economic efficiency of the reaction.

[0026] S4 sampling test: Sampling was performed regularly for product analysis, and substrate consumption and product formation were monitored using gas chromatography to ensure product quality and conversion rate.

[0027] S5 product separation and purification: Liquid products are obtained through condensation and separation of the water phase. The liquid products are distilled to separate the desired hydrocarbons. The light components in the products are used for gasoline and aviation fuel, and the heavy components are used for diesel.

[0028] The above trimetallic catalyst can be regenerated and reused, and the specific process is as follows: Regeneration method: Regeneration is performed at 500°C in a hydrogen environment to remove carbon deposits and pollutants on the catalyst surface and restore catalyst activity.

[0029] Regeneration cycle: Regeneration is performed every 20-50 reaction cycles. The specific time depends on the use of the catalyst.

[0030] As a preferred technical solution, in the reaction process of the present invention, the amount of catalyst used is 0.5-2 wt%. The amount of catalyst used directly affects the conversion rate and selectivity of the reaction. Reasonable adjustment of the amount of catalyst used can balance the reaction rate. Due to the high activity of trimetallic catalysts, the amount used is less than that of traditional monometallic or bimetallic catalysts, thereby reducing production costs.

[0031] As a preferred technical solution, in the reaction process of the present invention, the hydrogenation catalytic reaction time is 2-6 hours. The reaction time depends on the reaction type and substrate concentration. Too long a time may lead to catalyst deactivation or increase of by-products, while too short a time may lead to incomplete reaction.

[0032] As a preferred option, trimetallic catalysts can usually shorten the reaction time to 3-4 hours due to their high efficiency, thereby improving production efficiency.

[0033] Preferably, the following is a data comparison table of the sulfur content of the product after conventional technology treatment and the sulfur content of the product after the treatment of the present invention.

[0034]

Claims

1. A method for synthesizing hydrocarbon fuels using trimetallic catalyzed sulfur-containing biomass derivatives, characterized in that: Follow these steps: S1 Raw material pretreatment: remove impurities and moisture from the raw materials by filtering and preheating; S2 Catalyst loading: uniformly loading the trimetallic catalyst into the fixed bed reactor; S3 hydrogenation catalytic reaction: control the reaction temperature in the fixed bed reactor at 250-300°C, maintain the reaction pressure at 2-5MPa; input hydrogen, the molar ratio of hydrogen to raw material is 2:1-5:1; S4 Sampling and testing: Regular sampling for product analysis, using gas chromatography to monitor substrate consumption and product formation; S5 Product separation and purification: obtain liquid products through condensation and separation of water phase; The liquid product is distilled to separate the desired hydrocarbons.

2. The method for synthesizing hydrocarbon fuels from sulfur-containing biomass derivatives using trimetallic catalysts according to claim 1, characterized in that: In step S2, the tri-metal catalyst includes metal components of nickel, cobalt, molybdenum and a carrier of aluminum oxide.

3. The method for synthesizing hydrocarbon fuels from sulfur-containing biomass derivatives using trimetallic catalysts according to claim 2, characterized in that: The preparation steps of the trimetallic catalyst are as follows: (1) calcining the carrier at 500-600°C in air for 2-4 hours; (2) dissolving soluble metal salts of nickel, cobalt and molybdenum in deionized water to form a metal precursor solution of a certain concentration; (3) Immerse the support in the metal precursor solution and stir at room temperature for 12-15 hours; (4) drying the impregnated support at 100-120° C. for 6-12 hours; and then calcining at 400-500° C. for 2-4 hours to reduce the metal precursor and attach it to the support to form metal nanoparticles; (5) The catalyst produced in step (4) is subjected to reduction treatment in hydrogen at 300-400° C. for 2-3 hours to finally form a trimetallic catalyst.

4. The method for synthesizing hydrocarbon fuels from sulfur-containing biomass derivatives using trimetallic catalysts according to claim 3, characterized in that: In the metal precursor solution, the concentration ratio of soluble metal salts of nickel, cobalt and molybdenum dissolved in deionized water is 0.1-0.5M: 0.1-0.5M: 0.1-0.5M.

5. The method for synthesizing hydrocarbon fuels from sulfur-containing biomass derivatives using trimetallic catalysts according to claim 2, characterized in that: The trimetallic catalyst can be regenerated and the regeneration process is as follows: (1) Regeneration method: Regeneration is performed at 500°C in a hydrogen environment to remove carbon deposits and pollutants on the catalyst surface and restore catalyst activity; (2) Regeneration cycle: Regeneration is performed every 20-50 reaction cycles.

6. The method for synthesizing hydrocarbon fuels from sulfur-containing biomass derivatives using trimetallic catalysts according to claim 1, characterized in that: The amount of the trimetallic catalyst used in the fixed bed reactor is 0.5-2wt%.

7. The method for synthesizing hydrocarbon fuels from sulfur-containing biomass derivatives using trimetallic catalysts according to claim 1, characterized in that: In step S3, the time of the hydrogenation catalytic reaction is 2-6 hours.

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