Process for the preparation of biomass fischer-tropsch diesel

Abstract

The application discloses a preparation method of biomass Fischer-Tropsch synthesis diesel oil, which comprises the following steps: converting cellulose and lignin in biomass into biomass synthesis injection powder fuel through superheated steam pressure reduction hydrothermal carbonization of wood fiber biomass raw materials; producing biomass synthesis gas through pressurized entrained flow bed high-temperature gasification of the biomass synthesis injection powder fuel, wherein the gasification agent is oxygen and water vapor, and the biomass synthesis gas is adjusted to H / C=2-3:1; and producing biomass Fischer-Tropsch synthesis diesel oil through a Fischer-Tropsch synthesis process of the biomass synthesis gas. The biomass Fischer-Tropsch synthesis diesel oil can be produced in a large scale and continuously by using the biomass synthesis injection powder fuel obtained through superheated steam pressure reduction hydrothermal carbonization of biomass.

Description

Preparation method of biomass Fischer-Tropsch synthetic diesel Technical Field

[0001] This invention belongs to the field of coal processing technology, and specifically relates to a method for preparing biomass Fischer-Tropsch synthetic diesel. Background Technology

[0002] Human energy has primarily evolved through biomass (energy released: 1.2 × 10⁻⁶). 7 J / kg), coal (energy released by anthracite: 3.4×10 7 J / kg), petroleum (gasoline energy release: 4.6×10 7 In the three stages of energy conversion (J / kg), the core driving force is the improvement of energy density.

[0003] Currently, the most popular energy sources, such as photovoltaics, wind power, batteries, and hydrogen energy (energy release: 1.4 × 10^7 J / kg), are all low-energy-density energy sources. The fundamental reason why biomass was phased out in the early stages was its low energy density; this inherent defect will ultimately lead it to the same fate. The search for sustainable, high-energy-density renewable energy sources has become a global focus of intense competition.

[0004] Solar energy is the cheapest renewable energy source and has become an important component of human energy consumption. Biomass is the most ideal solar thermal energy storage carrier and is also an internationally recognized zero-carbon energy source. It relies on plant photosynthesis to fix and absorb solar energy, and its energy balance is achieved. In terms of energy payback time (EPT), biomass is only 5–75 days, while photovoltaic power generation takes 2–3 years. Converting biomass into high-energy-density energy using modern high-tech methods is an inevitable path.

[0005] Coal is a thick layer of black humus accumulated on the ground over millions of years from the branches, leaves, and roots of plants. Due to crustal movements, it is continuously buried underground, isolated from air for extended periods, and undergoes a series of complex physicochemical changes under high temperature and pressure to form a black, combustible sedimentary rock. It generally exists in block form and is ground into fine powder for injection before use, then transported pneumatically, such as in coal-fired combined heat and power (CHP), coal gasification, and blast furnace ironmaking. Lump coal can no longer be used directly. The biggest difference between biomass and coal lies in its high moisture content (difficult to utilize), extremely high oxygen content (over 45%), low density and low calorific value, inability to be pneumatically transported as powder, and difficulties in storage and transportation. Therefore, although both are solid fuels, biomass cannot replace coal.

[0006] However, due to its inherent characteristics, coal, as a biomass, has a low direct gasification temperature and contains tar, making it unsuitable as biomass syngas. Summary of the Invention

[0007] The purpose of this invention is to provide a method for preparing biomass Fischer-Tropsch synthetic diesel, which utilizes biomass to obtain biomass synthetic pulverized fuel through hydrothermal carbonization by depressurization of hot steam, enabling large-scale continuous production of biomass Fischer-Tropsch synthetic diesel.

[0008] To achieve the above objectives, the technical solution used in this invention is:

[0009] Methods for preparing biomass Fischer-Tropsch diesel include:

[0010] The process involves using lignocellulosic biomass raw materials to undergo superheated steam depressurization and hydrothermal carbonization, converting the cellulose and lignin in the biomass into biomass synthetic pulverized fuel.

[0011] Biomass syngas is produced by high-temperature gasification of pulverized biomass fuel in a pressurized fluidized bed. The gasifying agents are oxygen and water vapor, and the H / C ratio of the biomass syngas is adjusted to 2-3:1.

[0012] Biomass syngas is produced using the Fischer-Tropsch synthesis process to produce biomass Fischer-Tropsch diesel.

[0013] Furthermore, the raw materials undergo a high-temperature, high-pressure steam reaction to convert hemicellulose in biomass into furfural. The temperature is 260-280℃, the pressure is 2.4-2.6MPa, and the time is 0.5-5 minutes. The reaction converts hemicellulose in biomass into furfural. The furfural is then depressurized to synthesize pulverized coal fuel. The temperature is 160-180℃, the pressure is 1.0-1.2MPa, and the time is 5-30 minutes. The reaction ultimately converts cellulose and lignin in biomass into biomass-synthesized pulverized coal fuel.

[0014] Furthermore, a pressurized fluidized bed high-temperature gasifier is used to produce biomass syngas from biomass synthetic pulverized fuel. The raw material is biomass synthetic pulverized fuel, and the gasifying agent is oxygen and water vapor. The gasification temperature is 1200-1800℃, and the gasification pressure is 2.5-3.5MPa, producing biomass syngas mainly composed of H2 and CO.

[0015] Furthermore, the Fischer-Tropsch synthesis process uses a slurry bed reactor to produce biomass Fischer-Tropsch synthetic diesel, with a reaction temperature of 230-260℃, a pressure of 2.5-3.5MPa, and an iron-based catalyst.

[0016] The technical effects of this invention include:

[0017] 1. This invention utilizes biomass to obtain biomass synthetic pulverized coal fuel after depressurization and hydrothermal carbonization with hot steam. This fuel can replace pulverized coal and can achieve high-temperature gasification, enabling continuous production of biomass syngas.

[0018] 2. This invention utilizes biomass syngas and employs the Fischer-Tropsch synthesis process to produce biomass Fischer-Tropsch synthetic diesel.

[0019] This invention utilizes biomass pulverized fuel injected via pressurized fluidized bed high-temperature gasification to produce biomass syngas, replacing coal-based biomass syngas. Using biomass syngas as raw material, and employing existing processes and equipment for extending coal-based biomass syngas products, a series of biomass products can be successfully produced, such as biomass Fischer-Tropsch diesel, biomass synthetic natural gas, biohydrogen, bioammonia, and biourea.

[0020] 3. This invention uses biomass as raw material to develop two platforms: biomass synthetic pulverized fuel and biomass syngas, extending the production of biomass Fischer-Tropsch synthetic diesel. The raw material sources are wide-ranging, the process is green, suitable for industrial production, and can completely replace coal-based products.

[0021] Using lignocellulosic biomass as raw material, the raw materials are cheap, readily available, and widely sourced. Most of the raw materials used are agricultural and forestry residues and organic household waste, which belongs to the high-value recycling of low-quality resources.

[0022] 4. The superheated steam depressurization hydrothermal carbonization process is adopted to convert hemicellulose into furfural, and cellulose and lignin into biomass synthetic pulverized fuel, realizing the full utilization of biomass components.

[0023] 5. The pressurized fluidized bed high-temperature gasification process has high gasification efficiency, high gasification temperature, and high quality of biomass syngas. It is especially suitable for Fischer-Tropsch synthesis and methanation processes, and can be used for large-scale continuous production of biomass Fischer-Tropsch synthetic diesel.

[0024] Biomass Fischer-Tropsch synthetic diesel has the characteristics of high cetane number, high calorific value, complete combustion and good low-temperature fluidity. It can replace coal-based Fischer-Tropsch synthetic diesel, natural gas-based Fischer-Tropsch synthetic diesel and other fossil-based diesel. Biomass Fischer-Tropsch synthetic diesel can be used in diesel engine power equipment. Detailed Implementation

[0025] The following description fully illustrates specific embodiments of the invention to enable those skilled in the art to practice and reproduce them.

[0026] This invention uses lignocellulosic biomass (agricultural and forestry residues, organic biomass waste, and resource crops) as raw material. After being depressurized by hot steam and hydrothermally carbonized, the resulting biomass synthetic pulverized fuel is used as raw material. Biomass syngas is produced through a pressurized fluidized bed high-temperature gasification process, and then biomass Fischer-Tropsch synthetic diesel is produced through a Fischer-Tropsch synthesis process.

[0027] The specific steps for preparing biomass Fischer-Tropsch diesel are as follows:

[0028] (1) The cellulose and lignin in the biomass are converted into biomass synthetic pulverized fuel by superheated steam depressurization and hydrothermal carbonization of wood fiber biomass raw materials.

[0029] The process of synthesizing pulverized coal fuel from lignocellulosic biomass (agricultural and forestry residues, organic biomass waste, and resource crops) through hot steam depressurization and hydrothermal carbonization includes the following steps:

[0030] The raw materials undergo a high-temperature, high-pressure reaction with hot steam to convert hemicellulose in biomass into furfural. The temperature is 260-280℃, the pressure is 2.4-2.6MPa, and the time is 0.5-5 minutes.

[0031] The furfural depressurization reaction is used to synthesize pulverized fuel. The temperature is 160-180℃, the pressure is 1.0-1.2MPa, and the time is 5-30 minutes. The reaction ultimately converts the cellulose and lignin in biomass into biomass-synthesized pulverized fuel.

[0032] (2) Biomass syngas is produced by high-temperature gasification of biomass pulverized fuel in a pressurized fluidized bed. The gasifying agent is oxygen and water vapor. The H / C ratio of biomass syngas is adjusted to 2-3:1.

[0033] Biomass syngas is produced using a pressurized fluidized bed high-temperature gasifier with biomass pulverized fuel. The raw material is biomass pulverized fuel, and the gasifying agents are oxygen and water vapor. The gasification temperature is 1200-1800℃, and the gasification pressure is 2.5-3.5MPa. The produced biomass syngas is mainly composed of H2 and CO. The gas ratio is further adjusted to H / C = 2-3:1.

[0034] (3) Biomass syngas is produced by the Fischer-Tropsch synthesis process to produce biomass Fischer-Tropsch diesel.

[0035] The Fischer-Tropsch synthesis process produces biomass Fischer-Tropsch diesel fuel using biomass syngas as feedstock. It employs a slurry bed reactor with a reaction temperature of 230-260℃, a pressure of 2.5-3.5MPa, and an iron-based catalyst.

[0036] Example 1:

[0037] (1) 200 kg of tree branches (moisture content 21%) are shredded to less than 1 cm and enter the first stage of superheated steam high temperature and high pressure reactor reaction, including: temperature 265℃, pressure 2.4 MPa, time 4 minutes, hemicellulose in straw is converted into furfural gas and discharged, cellulose and lignin enter the second stage depressurization reactor; including temperature 170℃, pressure 1.05 MPa, time 24 minutes, cellulose and lignin are converted into 149 kg of biomass synthetic injection powder fuel (moisture content 8.95%).

[0038] The characteristic indicators of biomass synthetic pulverized coal fuel are as follows:

[0039]

[0040] (2) 149 kg of biomass pulverized fuel was fed into a pressurized fluidized bed high-temperature gasifier to produce biomass syngas. The biomass pulverized fuel had a particle size of 100 mesh, and the gasifying agents were oxygen and water vapor. The gasification temperature was 1450℃, and the gasification pressure was 2.8 MPa. The gas then entered a purification device and a steam reforming device, and the H / C ratio was adjusted to 2.1:1 to obtain 149 Nm³ of biomass syngas. 3 .

[0041] The characteristics of biomass syngas are as follows:

[0042] Project technical specifications: H2 / % 62.1%, CO / % 37.8%, CO2 / % 0.05%, CH4 / % 0.05 surface

[0043] (3) Fischer-Tropsch synthetic biomass Fischer-Tropsch synthetic diesel, with an air intake of 149 Nm³. 3 A slurry bed reactor was used, in which biomass syngas was introduced into the reactor at a reaction temperature of 240℃ and a reaction pressure of 2.8MPa. The catalyst was an iron-based catalyst. The product was selected from C12-C22 components, and a total of 52.5 kg of biomass Fischer-Tropsch diesel was obtained.

[0044] The characteristics of biomass Fischer-Tropsch synthetic diesel are as follows:

[0045]

[0046] Example 2:

[0047] (1) 200kg of bamboo (moisture content 22%) is crushed to less than 1cm and enters the first stage of superheated steam high temperature and high pressure reactor reaction, including: temperature 270℃, pressure 2.5MPa, time 4.5 minutes, the hemicellulose in bamboo is converted into furfural gas and discharged, and cellulose and lignin enter the second stage depressurization reactor; including temperature 165℃, pressure 1.1MPa, time 20 minutes, the cellulose and lignin are converted into 150.5kg of biomass synthetic injection powder fuel (moisture content 9.02%) respectively.

[0048] The characteristic indicators of biomass synthetic pulverized coal fuel are as follows:

[0049]

[0050] (2) 150.5 kg of biomass pulverized fuel was fed into a pressurized fluidized bed high-temperature gasifier to produce biomass syngas. The biomass pulverized fuel had a particle size of 100 mesh, and the gasifying agents were oxygen and water vapor. The gasification temperature was 1600℃, and the gasification pressure was 3.0 MPa. The gas then entered a purification device and a steam reforming device, and the H / C ratio was adjusted to 2.2:1 to obtain 152 Nm³ of biomass syngas. 3 .

[0051] The characteristics of biomass syngas are as follows:

[0052]

[0053]

[0054] (3) Fischer-Tropsch synthesis of biomass Fischer-Tropsch diesel, including an intake gas volume of 152 Nm3; a slurry bed reactor is used, the biomass syngas is introduced into the reactor, the reaction temperature is 245℃, the reaction pressure is 3.2 MPa; the catalyst is an iron-based catalyst; the product is selected from C12-C22 components, and a total of 52.7 kg of biomass Fischer-Tropsch diesel is obtained.

[0055] The characteristics of biomass Fischer-Tropsch synthetic diesel are as follows:

[0056]

[0057] Example 3:

[0058] (1) 200kg of waste wooden furniture (moisture content 8%) is crushed to less than 1cm and enters the first stage of superheated steam high temperature and high pressure reactor reaction, including: temperature 280℃, pressure 2.6MPa, time 5 minutes, hemicellulose in waste wooden furniture is converted into furfural gas and discharged, cellulose and lignin enter the second stage depressurization reactor; including temperature 180℃, pressure 1.2MPa, time 30 minutes, cellulose and lignin are converted into 179.5kg of biomass synthetic injection powder fuel (moisture content 8.92%) respectively.

[0059] The characteristic indicators of biomass synthetic pulverized coal fuel are as follows:

[0060]

[0061] (2) 179.5 kg of biomass pulverized fuel was fed into a pressurized fluidized bed high-temperature gasifier to produce biomass syngas. The biomass pulverized fuel had a particle size of 100 mesh, and the gasifying agents were oxygen and water vapor. The gasification temperature was 1650℃, and the gasification pressure was 3.5 MPa. The gas then entered a purification device and a steam reforming device, and the H / C ratio was adjusted to 2.5:1 to obtain 185 Nm³ of biomass syngas. 3 .

[0062] The characteristics of biomass syngas are as follows:

[0063] Project technical specifications: H2 / % 62.5%, CO / % 37.4%, CO2 / % 0.02%, CH4 / % 0.08 surface

[0064] (3) Toro Synthetic biomass Fischer-Tropsch diesel, including an intake gas volume of 185 Nm3; a slurry bed reactor is used, the biomass syngas is introduced into the reactor, the reaction temperature is 260℃, the reaction pressure is 3.5 MPa; the catalyst is an iron-based catalyst; the product is selected from C12-C22 components, and a total of 62.8 kg of biomass Fischer-Tropsch diesel is obtained.

[0065] The characteristics of biomass Fischer-Tropsch synthetic diesel are as follows:

[0066]

[0067] Example 4:

[0068] (1) 200 kg of corn stalks (moisture content 22%) are crushed to less than 1 cm and enter the first stage of the superheated steam high temperature and high pressure reactor reaction, including: temperature 240℃, pressure 2.4 MPa, time 3 minutes, the hemicellulose in the corn stalks is converted into furfural gas and discharged, and the cellulose and lignin enter the second stage depressurization reactor; including temperature 160℃, pressure 1.1 MPa, time 20 minutes, the cellulose and lignin are converted into 130.5 kg of biomass synthetic injection powder fuel (moisture content 9.45%) respectively.

[0069] The characteristic indicators of biomass synthetic pulverized coal fuel are as follows:

[0070]

[0071] (2) 130.5 kg of biomass pulverized fuel was fed into a pressurized fluidized bed high-temperature gasifier to produce biomass syngas. The biomass pulverized fuel had a particle size of 100 mesh, and the gasifying agents were oxygen and water vapor. The gasification temperature was 1550℃, and the gasification pressure was 2.5 MPa. The gas then entered a purification device and a steam reforming device, and the H / C ratio was adjusted to 2.3:1 to obtain 135 Nm³ of biomass syngas. 3 .

[0072] The characteristics of biomass syngas are as follows:

[0073] Project technical specifications: H2 / % 62.0, CO / % 37.9, CO2 / % 0.07, CH4 / % 0.03 surface

[0074] (3) Fischer-Tropsch synthesis of biomass Fischer-Tropsch diesel, including an intake gas volume of 135 Nm3; a slurry bed reactor is used, the biomass syngas is introduced into the reactor, the reaction temperature is 250℃, the reaction pressure is 3.0 MPa; the catalyst is an iron-based catalyst; the product is selected from C12-C22 components, and a total of 45.6 kg of biomass Fischer-Tropsch diesel is obtained.

[0075] The characteristics of biomass Fischer-Tropsch synthetic diesel are as follows:

[0076]

[0077] The terminology used in this invention is descriptive and exemplary, not restrictive. Since this invention can be embodied in many forms without departing from the spirit or essence of the technical solution, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims. Therefore, all variations and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A method for preparing biomass Fischer-Tropsch diesel, characterized in that, include: Using lignocellulosic biomass as raw material, the hemicellulose in the biomass is converted into furfural gas through a high-temperature, high-pressure steam reaction at 260-280℃ and 2.4-2.6 MPa for 0.5-5 minutes. Following this, superheated steam is used for depressurization hydrothermal carbonization at 160-180℃ and 1.0-1.2 MPa. At a pressure of 1200-1800℃ and a pressure of 2.5-3.5 MPa, the biomass synthetic pulverized fuel is converted into biomass synthetic fuel through a pressurized fluidized bed gasification process. The raw material is biomass synthetic pulverized fuel, and the gasification agents are oxygen and steam. The gasification temperature is 1200-1800℃, and the gasification pressure is 2.5-3.5 MPa, producing a gas mainly composed of H2 and CO. The gas then enters a purification unit and a steam reforming unit to adjust the H / C ratio to 2-3:1, yielding biomass synthetic gas. The biomass synthetic gas is then used in a Fischer-Tropsch synthesis process to produce biomass Fischer-Tropsch diesel. This process uses a slurry bed reactor at a reaction temperature of 230-260℃ and a pressure of 2.5-3.5 MPa, with an iron-based catalyst.

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