Biomass pyrolysis system with catalytic cracking unit and rotary furnace coupled and method for producing biogas

Abstract

The invention discloses a catalytic cracking device and rotary furnace coupled biomass pyrolysis system and a method for producing biogas. The system comprises a catalytic cracking settler, a catalytic cracking regenerator, a catalytic cracking fractionating tower, a rotary furnace, a condensation cooler and a flash tower, the catalytic cracking settler, the catalytic cracking regenerator and the rotary furnace are communicated through pipelines; the rotary furnace is provided with a settling chamber for gas-solid separation, and the settling chamber is provided with a pyrolysis product gas phase outlet and a pyrolysis product solid phase outlet; the pyrolysis product gas phase outlet is sequentially communicated with a condensation cooler, a flash tower and a catalytic cracking fractionating tower; and the pyrolysis product solid phase outlet is communicated with a catalytic cracking settler. The catalytic cracking device regenerated catalyst is used as a heat source, and the regenerated catalyst is introduced into the rotary furnace of the biomass pyrolysis reactor, so that the investment and operation cost of independent biomass pyrolysis equipment are saved.

Description

Field of the Invention

[0001] The invention relates to a biomass pyrolysis system in which a catalytic cracking device is coupled with a rotary furnace and a method for producing biogas, and belongs to the field of petroleum refining. Background Art

[0002] Biomass energy is produced by photosynthesis of plants. Biomass can absorb and store solar energy within itself and convert it into its own chemical energy. Previous statistics show that the total reserves of biomass energy are ranked fourth among all energy reserves, and the annual consumption of biomass energy accounts for 14% of the world's total energy consumption. Compared with other renewable energy sources, biomass energy is the only energy that can produce gaseous and liquid products. After upgrading, bio-oil can effectively supplement the utilization of petroleum resources.

[0003] my country has abundant biomass resources, and biomass energy can be burned directly. However, this direct combustion method often only utilizes the heat generated during the combustion of biomass, and fails to fully utilize the biomass energy, resulting in a waste of biomass energy. At the same time, it also fails to meet the development of today's society and the needs of human beings to use energy in a clean way. Moreover, the biomass resources currently used are mainly agricultural and forestry biomass, which has a cyclical growth, occupies a large storage area and is susceptible to moisture and rot, which has caused great inconvenience to the supply of actual continuous industrial application raw materials. Therefore, the use of clean and efficient biomass energy utilization technology to directly convert biomass energy into biogas that is easy to store and utilize meets the needs of the market.

[0004] At present, the contradiction between ecological environment and fossil energy is becoming increasingly serious, and the development and utilization of renewable and new clean energy is very urgent. There are many ways to develop and utilize biomass energy, mainly in the following three categories: physical conversion technology, thermochemical conversion technology, and biochemical conversion technology. Physical conversion technology is mainly compression molding technology. The density, strength and particle size uniformity of biomass raw materials converted by compression molding technology are increased, making the storage and transportation of biomass energy more convenient. The biomass processed by this method is mainly used for direct combustion. The main purpose of thermochemical conversion technology is to obtain high-grade energy products such as charcoal, biomass fuel oil and biogas. This method is mainly based on the direct combustion of biomass into the equipment, which is directly burned or mixed with coal and other minerals. The energy generated is then used. The biomass fuel oil and biogas obtained by this method cannot be stored and must be used immediately after production.

[0005] Biomass pyrolysis technology is a type of thermochemical conversion technology. Pyrolysis refers to the process in which heat-absorbing biomass macromolecules break into small molecules in the absence of oxygen. The purpose of pyrolysis is to obtain biogas, bio-oil and biochar. Pyrolysis can effectively and fully convert low-energy-density biomass raw materials into high-energy-density gas, liquid and solid products, with a high energy output ratio. Therefore, the development and utilization of biomass energy is an important part of the revolution in energy production and consumption, and an important task to improve environmental quality and develop a circular economy.

[0006] Catalytic cracking technology is a mature petroleum secondary processing technology, which has advantages in investment, operating costs, technical reliability, raw material adaptability and conversion depth, investment recovery rate, etc. The typical catalytic cracking process consists of a reaction-regeneration, fractionation, absorption-stabilization system, using molecular sieve catalysts, fluidized bed operation, and the catalyst is recycled after being burned to restore activity.

[0007] Biomass pyrolysis is an endothermic reaction, a process in which biomass endothermic macromolecules break down to generate small molecules. During the regeneration process of the catalytic cracking catalyst in the regenerator, excess heat is generated. In addition to meeting the heat required for the catalytic cracking reaction, an external heat extractor is usually used to remove the heat to meet the thermal balance of the catalytic cracking reaction-regeneration system. Summary of the invention

[0008] Pyrolysis refers to the process in which biomass absorbs heat and breaks into small molecules in the absence of oxygen. The purpose of pyrolysis is to obtain three high-value products: bio-oil, biochar and biogas. Pyrolysis can effectively and fully convert low-energy-density biomass raw materials into high-energy-density gas, liquid and solid products, with a high energy output ratio.

[0009] The present invention utilizes the catalyst in the catalytic cracking regenerator as a heat source for biomass pyrolysis, realizes biomass pyrolysis in a rotary furnace, and the pyrolysis products are subsequently processed through the original reaction-regeneration and fractionation system of the catalytic cracking device, thereby realizing the coupling process of the catalytic cracking device and the rotary furnace to process biomass and ultimately produce biogas.

[0010] On the one hand, the present invention provides a biomass pyrolysis system in which a catalytic cracking device is coupled with a rotary furnace, wherein the biomass pyrolysis system comprises a catalytic cracking settler, a catalytic cracking regenerator, a catalytic cracking fractionation tower, a rotary furnace, a condenser cooler and a flash tower; the catalytic cracking settler, the catalytic cracking regenerator and the rotary furnace are connected via pipelines; the rotary furnace has a settling chamber for gas-solid separation, and the settling chamber has a pyrolysis product gas phase outlet and a pyrolysis product solid phase outlet; the pyrolysis product gas phase outlet is sequentially connected to the condenser cooler, the flash tower and the catalytic cracking fractionation tower; the pyrolysis product solid phase outlet is connected to the catalytic cracking settler.

[0011] As a preferred embodiment, the rotary furnace has a feed end and a discharge end, the catalytic cracking regenerator is connected to the feed end of the rotary furnace, and the settling chamber is located at the discharge end of the rotary furnace.

[0012] The catalytic cracking unit in the present invention is a conventional and universal device in the technical field of secondary petroleum processing, usually including a catalytic cracking settler, a catalytic cracking regenerator and a catalytic cracking fractionation tower. The specific structure is not limited, and a fluidized catalytic cracking unit is preferably used.

[0013] In the technical field of secondary petroleum processing, catalytic cracking settler, catalytic cracking regenerator and catalytic cracking fractionator are conventional and general equipment, which are the main components of catalytic cracking unit, and the specific structure is not limited.

[0014] Optionally, the rotary kiln is a cylindrical structure, with rotary seals at both ends, and the cylinder can rotate along the central axis, and the central axis of the cylinder has an angle of 2 to 5 degrees with the horizontal line.

[0015] Optionally, 1 to 10 plates without overflow weirs are provided from the feed end to the top of the flash tower.

[0016] Optionally, a stirring device is provided at the bottom of the flash tower; the stirring device is used to prevent a small amount of carbon deposited catalyst from depositing.

[0017] Optionally, the catalytic cracking settler has a steam stripping component.

[0018] As a preferred embodiment, the outlet of the catalytic cracking settler is connected to the first catalytic cracking regenerator.

[0019] Optionally, the settling chamber has 1 to 10 groups of cyclone separators for gas-solid separation.

[0020] On the other hand, the present invention provides a method for producing biogas by pyrolyzing biomass using a catalytic cracking device and a rotary kiln, wherein the biomass and the regenerated catalyst from the catalytic cracking device undergo a catalytic pyrolysis reaction in a rotary kiln to obtain a solid pyrolysis product and a gaseous pyrolysis product; the gaseous pyrolysis product undergoes flash evaporation to obtain a gaseous substance and a liquid substance; the liquid substance is fed to the rotary kiln and circulated to undergo a catalytic pyrolysis reaction; the gaseous substance is biogas. The liquid substance in the flash tower is mainly composed of liquid bio-oil and contains a small amount of water.

[0021] Optionally, the gas phase includes: H 2 , C 1 ~C 4 of hydrocarbons.

[0022] Preferably, the hot gaseous product is condensed and cooled before entering a flash tower for flash evaporation.

[0023] Optionally, the gas phase is pressurized at the top of the flash tower and then enters the catalytic cracking fractionation tower to separate C 1 ~C 4 The hydrocarbons are fractionated.

[0024] Optionally, the liquid phase enters a rotary furnace from the bottom of the flash tower to cyclically perform a catalytic pyrolysis reaction.

[0025] Optionally, the solid phase pyrolysis product is sent to a catalytic cracking settler of a catalytic cracking unit, stripped with water vapor, and then sent to a catalytic cracking regenerator to burn off carbon deposits, and is recycled as a regenerated catalyst.

[0026] Optionally, the rotary kiln is a cylindrical structure with rotating seals provided at both ends, the central axis of the cylinder forms an angle of 2 to 5° with the horizontal line, and the cylinder rotates along the central axis.

[0027] Optionally, the liquid phase includes bio-oil and water; the bio-oil includes C 5 ~C 30 Hydrocarbons and C 5 ~C 30 of oxygen-containing organic compounds.

[0028] Optionally, the regenerated catalyst is from a catalytic cracking regenerator.

[0029] Optionally, the temperature of the regenerated catalyst is 650-750°C.

[0030] Optionally, the biomass particles have a particle size of 1 to 10 mm and contain 0 to 20 wt% water.

[0031] Optionally, the amount of the regeneration catalyst used is 5 to 10 times that of the biomass.

[0032] Optionally, when the liquid phase is present in the rotary kiln, the amount of the regeneration catalyst used is 5 to 10 times the total mass of the biomass and the liquid phase.

[0033] Optionally, the gas phase velocity at the inlet of the cyclone separator is 15 to 25 m / s.

[0034] Optionally, the reaction conditions in the rotary kiln include: a pressure of 5 to 10 KPa(g); and a catalytic pyrolysis reaction time of 60 to 120 minutes.

[0035] Optionally, the conditions for gas-liquid separation of the flash evaporation (conditions in the flash tower) include: temperature 40-60° C., pressure 5-10 KPa(g).

[0036] Optionally, the conditions for the gas phase to enter the catalytic cracking distillation tower for fractionation after being pressurized at the top of the flash tower include: temperature 40-60° C., pressure 0.10-0.25 MPa(g).

[0037] Optionally, the solid phase pyrolysis product is steam stripped after entering the catalytic cracking settler, and the conditions of the steam stripping include: the temperature of the solid phase pyrolysis product is 400-550°C and the pressure is 0.12-0.25MPa(g); the steam temperature is 250-350°C and the pressure is 0.3-0.8MPa(g), and the steam dosage is 3%-5% of the mass of the solid phase pyrolysis product.

[0038] Optionally, the solid phase pyrolysis product is steam stripped in a catalytic cracking settler and then sent to a catalytic cracking regenerator to burn off carbon deposits, and is recycled as a regenerated catalyst.

[0039] The biomass pyrolysis system of the catalytic cracking device coupled with the rotary furnace disclosed in the present invention utilizes the regenerated catalyst of the catalytic cracking device as a heat source, and introduces the regenerated catalyst into the rotary furnace of the biomass pyrolysis reactor. In the rotary furnace, the catalyst and the biomass undergo a pyrolysis reaction. A pyrolysis product gas phase and a pyrolysis product solid phase are generated. The pyrolysis product gas phase enters a flash tower after condensation and cooling, and the gas phase at the top of the flash tower enters a catalytic cracking fractionation tower after pressure increase; the liquid bio-oil at the bottom of the flash tower is sent to the rotary furnace for cyclic pyrolysis. The pyrolysis product solid phase is sent to the settler of the catalytic cracking device, and after water vapor stripping, it is sent to the catalytic cracking regenerator to burn off the carbon deposits, and is cyclically used as a regenerated catalyst.

[0040] Compared with the fixed bed and rotary furnace biomass pyrolysis methods, biomass pyrolysis alone requires the addition of 3-10% active Al 2 O 3 Catalysts such as Al 2 O 3 The catalyst is mixed with the biochar, so that the biochar cannot be fully utilized. For example, the biochar is burned during catalyst regeneration, resulting in heat loss of the biochar. The present invention couples the catalytic cracking device with a rotary kiln for biomass pyrolysis, which can increase the amount of catalyst to 5 to 10 times the biomass, which is conducive to the production of more biogas and solves the problem of catalyst regeneration. The heat released during catalyst regeneration is recovered by the external heat extraction system of the catalytic cracking regenerator, or can supplement the heat required by the catalytic cracking regeneration system, effectively utilizing the heat of the biochar. The present invention also effectively solves the problem of high bio-oil yield and low bio-oil utilization rate in conventional biomass pyrolysis.

[0041] Compared with the fluidized bed biomass pyrolysis method, the present invention couples the catalytic cracking device with the rotary furnace to perform biomass pyrolysis, thereby saving the investment and operation costs of separate biomass pyrolysis equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 Biomass through catalytic cracking unit and rotary furnace coupling system;

[0043] Figure 1 Among them, 1 is the first catalytic cracking regenerator, 2 is the second catalytic cracking regenerator, 3 is the rotary furnace, 3a is the settling chamber, 4 is the condenser cooler, 5 is the flash tower, 6 is the catalytic cracking fractionation tower, and 7 is the catalytic cracking settler. DETAILED DESCRIPTION

[0044] The following examples further illustrate the effects of the present invention.

[0045] Equipment example: Pyrolysis system with catalytic cracking unit coupled with rotary furnace

[0046] The present invention utilizes a pyrolysis system coupled with a catalytic cracking device and a rotary furnace to pyrolyze biomass to produce a process of biogas: biomass particles pass through a screw conveyor and enter the rotary furnace of a biomass pyrolysis reactor through a feed end, and are mixed with the regenerated catalyst from a second catalytic cracking regenerator. The rotary furnace is a cylindrical rotating structure, and the angle between the central axis of the cylinder and the horizontal line is 3°. The regenerated catalyst and biomass advance downstream in the rotary furnace and complete the pyrolysis reaction. The amount of the regenerated catalyst is 5 to 10 times the total mass of the biomass and bio-oil.

[0047] like Figure 1 As shown, the pyrolysis system of the catalytic cracking device coupled with the rotary furnace includes a catalytic cracking settler 7, a catalytic cracking regenerator 2, a catalytic cracking fractionation tower 6, a rotary furnace 3, a condenser cooler 4 and a flash tower 5; the catalytic cracking settler 7, the catalytic cracking regenerator 2 and the rotary furnace 3 are connected through pipelines; the rotary furnace has a settling chamber 3a for gas-solid separation, and the settling chamber 3a has a pyrolysis product gas phase outlet and a pyrolysis product solid phase outlet; the pyrolysis product gas phase outlet is connected to the condenser cooler 4, the flash tower 5, and the catalytic cracking fractionation tower 6 in sequence; the pyrolysis product solid phase outlet is connected to the catalytic cracking settler 7.

[0048] A steel cylinder with a diameter of 89×500 mm is used as the rotary furnace 3, and rotary seals are set at both ends of the cylinder. The feed end of the rotary furnace 3 adopts a double screw conveyor for feeding, and a settling chamber 3a is set at the discharge end. The upper end of the settling chamber is connected to a condenser cooler 4. A regenerated catalyst second catalytic cracking regenerator 2 (first hopper) and a first catalytic cracking regenerator 1 (second hopper) are set on the upper part of the outer sleeve of the screw conveyor, and the regenerated catalyst and the mixture of biomass particles / bio-oil are respectively loaded.

[0049] The regenerated catalyst in the first hopper is heated to 650-750°C, and the screw feeds of the two hoppers are opened respectively, and the materials in the two hoppers are pushed into the rotary kiln 3 through the feed end of the rotary kiln 3 after the air is replaced by water vapor in advance, and the pyrolysis reaction is carried out. The system pressure is adjusted by the opening of the pyrolysis gas phase outlet valve, the reaction time is adjusted by the rotation speed of the rotary kiln 3, and the quality of the catalyst and biomass / bio-oil is adjusted by the screw feed speed of the two hoppers.

[0050] As the rotary kiln rotates, the regenerated catalyst and biomass flow downstream and undergo a pyrolysis reaction to generate gas-phase pyrolysis products and solid-phase pyrolysis products. The residence time of the regenerated catalyst and biomass in the rotary kiln, i.e., the reaction time, is 60 to 120 minutes. A settling chamber 3a is provided at the rear end of the rotary kiln for separating gas-phase pyrolysis products and solid-phase pyrolysis products. In the settling chamber, the gas-phase pyrolysis products enter the condenser cooler 4 from the top of the settling chamber 3a, are cooled to a temperature of 40 to 60°C, and then enter the flash tower.

[0051] The solid pyrolysis product obtained from the bottom of the settling chamber is a mixture formed by the biochar produced by the pyrolysis of biomass adsorbed on the catalyst, which is sent to the catalytic cracking settler by a screw conveyor, and after steam stripping in the stripping section, it enters the first catalytic cracking regenerator and the second catalytic cracking regenerator for charring, and the charred catalyst is recycled. The first catalytic cracking regenerator and the second catalytic cracking regenerator are commonly connected in series in the art.

[0052] The gas phase pyrolysis product enters the condenser cooler 4 from the top of the settling chamber 3a, is cooled to a temperature of 40-60°C and enters the flash tower 5. At 5-10Kpa(g), the biogas at the top of the flash tower 5 is transferred to a gas collection bag for weighing and measurement; the bio-oil and water at the bottom of the flash tower 5 are separated and respectively put into collection bottles for weighing and measurement; the solid phase pyrolysis product at the bottom of the settling chamber 3a is stripped at a temperature of 400-550°C by water vapor at 250-350°C and a pressure of 0.3-0.8MPa(g), cooled to 50°C, weighed and measured, and the weight of the biochar is obtained by deducting the weight of the original catalytic cracking catalyst.

[0053] Biogas is obtained at the top of the flash tower, pressurized to 0.10-0.25 MPa(g), and enters the catalytic cracking fractionation tower 6 through a pipeline connected to the fractionation tower. Bio-oil and water are obtained at the bottom of the flash tower, wherein the bio-oil is returned to the feed end of the rotary kiln 3 for cyclic pyrolysis.

[0054] The biomass particles have a diameter of 3 mm and a water content of 10 wt %. The catalyst is a regenerated catalyst from a 1.3 million ton / year catalytic cracking unit.

[0055] In embodiments 1-8 of the present invention:

[0056] Product testing method:

[0057] Biogas is tested using multidimensional gas chromatography.

[0058] The bio-oil was tested by gas chromatography-mass spectrometry.

[0059] Calculation method of yield:

[0060] The calculation formula for the yield of biogas is: mass of biogas / (mass of biomass + mass of bio-oil).

[0061] The calculation formula of bio-oil yield is: bio-oil mass / (biomass mass+bio-oil mass).

[0062] The calculation formula for the yield of biochar is: mass of biochar / (mass of biomass + mass of bio-oil).

[0063] The calculation formula for the yield of pyrolysis water is: mass of pyrolysis water / (mass of biomass + mass of bio-oil).

[0064] Example 1

[0065] The system of the equipment example is adopted, and naturally dried corn stalks are used as biomass raw materials, which are crushed into 3 mm biomass particles with a water content of 10 wt%.

[0066] The first hopper was loaded with 250 g of catalytic cracking regeneration catalyst, and the second hopper was loaded with 50 g of biomass particles.

[0067] The regenerated catalyst in the first hopper is heated to 650°C, and the screw feeds of the two hoppers are opened respectively, and the materials in the two hoppers are pushed into the rotary kiln 3, which has replaced the air with water vapor in advance, for pyrolysis reaction. Under the conditions of a pressure of 5 Kpa(g) and a rotation speed of 2.0 rpm for all the solid pyrolysis products to enter the settling chamber 3a, the time is 60 minutes.

[0068] The gas phase pyrolysis product enters the condenser cooler 4 from the top of the settling chamber 3a, is cooled to a temperature of 40°C and enters the flash tower 5. At 5Kpa(g), the biogas at the top of the flash tower 5 is transferred to a gas collection bag for weighing and measurement; the bio-oil and water at the bottom of the flash tower 5 are separated and respectively put into a collection bottle for weighing and measurement; the solid phase pyrolysis product at the bottom of the settling chamber 3a is stripped at a temperature of 400°C by water vapor at 250°C and a pressure of 0.3MPa(g), cooled to 50°C, weighed and measured, and the weight of the original catalytic cracking catalyst is deducted to obtain the weight of the biochar. The obtained yield is shown in Table-1.

[0069] Table 1 Biomass pyrolysis yield

[0070] Cyclic pyrolysis product yield Yield, wt% Biogas 18.10％ Bio-oil 41.80％ Biochar 30.10％ water 10.00％ total 100.00％

[0071] The composition of biogas is analyzed. Biogas contains H 2 , C 1 ~C 4 of hydrocarbons.

[0072] The composition of bio-oil was analyzed. Bio-oil contains C 5 ~C 30hydrocarbons and their oxygen-containing organic compounds.

[0073] Example 2

[0074] The system of the equipment example is adopted, and naturally dried corn stalks are used as biomass raw materials, which are crushed into 3 mm particles with a water content of 10 wt%.

[0075] The first hopper was loaded with 400 g of catalytic cracking regeneration catalyst, and the second hopper was loaded with 25 g of biomass particles and 25 g of bio-oil.

[0076] The regenerated catalyst in the first hopper is heated to 650°C, and the screw feeds of the two hoppers are opened respectively, and the materials in the two hoppers are pushed into the rotary kiln 3, which has replaced the air with water vapor in advance, for pyrolysis reaction. Under the conditions of pressure 8Kpa(g) and rotary kiln 3 speed of 2.0 rpm, the time for all the solid phase of the pyrolysis product to enter the settling chamber 3a is 60 minutes.

[0077] The gas phase of the pyrolysis product enters the condenser cooler 4 from the top of the settling chamber 3a, is cooled to a temperature of 45°C and enters the flash tower 5. At 8Kpa(g), the biogas at the top of the flash tower 5 is transferred to a gas collection bag for weighing and measurement; the bio-oil and water at the bottom of the flash tower 5 are separated and respectively put into a collection bottle for weighing and measurement; the solid phase of the pyrolysis product at the bottom of the settling chamber 3a is stripped at a temperature of 450°C by water vapor at 300°C and a pressure of 0.5MPa(g), cooled to 50°C, weighed and measured, and the weight of the original catalytic cracking catalyst is deducted to obtain the weight of the biochar. The obtained yield is shown in Table-2.

[0078] Table 2 Biomass + bio-oil pyrolysis yield

[0079] Cyclic pyrolysis product yield Yield, wt% Biogas 41.43％ Bio-oil 7.72％ Biochar 40.85％ water 10.00％ total 100.00％

[0080] The composition of biogas is analyzed. Biogas contains H 2 , C 1 ~C 4 of hydrocarbons.

[0081] The composition of bio-oil was analyzed. Bio-oil contains C 5 ~C 30 hydrocarbons and their oxygen-containing organic compounds.

[0082] Example 3

[0083] The system of the equipment example is adopted, and naturally dried corn stalks are used as biomass raw materials, which are crushed into 3 mm particles with a water content of 10 wt%.

[0084] The first hopper was loaded with 500 g of catalytic cracking regeneration catalyst, and the second hopper was loaded with 25 g of biomass particles and 25 g of bio-oil.

[0085] The regenerated catalyst in the first hopper is heated to 650°C, and the screw feeds of the two hoppers are opened respectively, and the materials in the two hoppers are pushed into the rotary kiln 3, which has replaced the air with water vapor in advance, for pyrolysis reaction. Under the conditions of a pressure of 10Kpa(g) and a rotation speed of 2.0 rpm for the solid phase of the pyrolysis product to enter the settling chamber 3a, it takes 60 minutes.

[0086] The gas phase of the pyrolysis product enters the condenser cooler 4 from the top of the settling chamber 3a, is cooled to a temperature of 45°C and enters the flash tower 5. At 10Kpa(g), the biogas at the top of the flash tower 5 is transferred to a gas collection bag for weighing and measurement; the bio-oil and water at the bottom of the flash tower 5 are separated and respectively put into a collection bottle for weighing and measurement; the solid phase of the pyrolysis product at the bottom of the settling chamber 3a is stripped at a temperature of 500°C by water vapor at 250°C and a pressure of 0.8MPa(g), cooled to 50°C, weighed and measured, and the weight of the biochar is deducted from the weight of the original catalytic cracking catalyst. The obtained yield is shown in Table-3.

[0087] Table 3 Biomass + bio-oil pyrolysis yield

[0088] Cyclic pyrolysis product yield Yield, wt% Biogas 43.66％ Bio-oil 5.34％ Biochar 41.00％ water 10.00％ total 100.00％

[0089] The composition of biogas is analyzed. Biogas contains H 2 , C 1 ~C 4 of hydrocarbons.

[0090] The composition of bio-oil was analyzed. Bio-oil contains C 5 ~C 30 hydrocarbons and their oxygen-containing organic compounds.

[0091] Example 4

[0092] The system of the equipment example is adopted, and naturally dried corn stalks are used as biomass raw materials, which are crushed into 3 mm particles with a water content of 10 wt%.

[0093] The first hopper is loaded with 250 g of catalytic cracking regeneration catalyst, and the second hopper is loaded with 25 g of biomass particles and 25 g of bio-oil.

[0094] The regenerated catalyst in the first hopper is heated to 700°C, and the screw feeds of the two hoppers are opened respectively, and the materials in the two hoppers are pushed into the rotary kiln 3, which has replaced the air with water vapor in advance, for pyrolysis reaction. Under the conditions of pressure 8Kpa(g) and rotary kiln 3 speed of 2.0 rpm, the time for all the solid phase of the pyrolysis product to enter the settling chamber 3a is 60 minutes.

[0095] The gas phase of the pyrolysis product enters the condenser cooler 4 from the top of the settling chamber 3a, is cooled to a temperature of 50°C and enters the flash tower 5. At 8Kpa(g), the biogas at the top of the flash tower 5 is transferred to a gas collection bag for weighing and measurement; the bio-oil and water at the bottom of the flash tower 5 are separated and respectively put into a collection bottle for weighing and measurement; the solid phase of the pyrolysis product at the bottom of the settling chamber 3a is stripped at a temperature of 450°C by water vapor at 300°C and a pressure of 0.8MPa(g), cooled to 50°C, weighed and measured, and the weight of the original catalytic cracking catalyst is deducted to obtain the weight of the biochar. The obtained yield is shown in Table-4.

[0096] Table 4 Biomass + bio-oil pyrolysis yield

[0097] Cyclic pyrolysis product yield Yield, wt% Biogas 42.57％ Bio-oil 5.84％ Biochar 41.60％ water 10.00％ total 100.00％

[0098] The composition of biogas is analyzed. Biogas contains H 2 , C 1 ~C 4 of hydrocarbons.

[0099] The composition of bio-oil was analyzed. Bio-oil contains C 5 ~C 30 hydrocarbons and their oxygen-containing organic compounds.

[0100] Example 5

[0101] The system of the equipment example is adopted, and naturally dried corn stalks are used as biomass raw materials, which are crushed into 3 mm particles with a water content of 10 wt%.

[0102] The first hopper was loaded with 400 g of catalytic cracking regeneration catalyst, and the second hopper was loaded with 25 g of biomass particles and 25 g of bio-oil.

[0103] The regenerated catalyst in the first hopper is heated to 700°C, and the screw feeds of the two hoppers are opened respectively, and the materials in the two hoppers are pushed into the rotary kiln 3, which has replaced the air with water vapor in advance, for pyrolysis reaction. Under the conditions of a pressure of 5 Kpa(g) and a rotation speed of 2.0 rpm of the rotary kiln 3, the time for all the solid phase of the pyrolysis products to enter the settling chamber 3a is 60 minutes.

[0104] The gas phase of the pyrolysis product enters the condenser cooler 4 from the top of the settling chamber 3a, is cooled to a temperature of 60°C and enters the flash tower 5. At 5Kpa(g), the biogas at the top of the flash tower 5 is transferred to a gas collection bag for weighing and measurement; the bio-oil and water at the bottom of the flash tower 5 are separated and respectively put into collection bottles for weighing and measurement; the solid phase of the pyrolysis product at the bottom of the settling chamber 3a is stripped at a temperature of 450°C by water vapor at 350°C and a pressure of 0.3MPa(g), cooled to 50°C, weighed and measured, and the weight of the original catalytic cracking catalyst is deducted to obtain the weight of the biochar. The obtained yield is shown in Table-5.

[0105] Table 5 Biomass + bio-oil pyrolysis yield

[0106]

[0107]

[0108] The composition of biogas is analyzed. Biogas contains H 2 , C 1 ~C 4 of hydrocarbons.

[0109] The composition of bio-oil was analyzed. Bio-oil contains C 5 ~C 30 hydrocarbons and their oxygen-containing organic compounds.

[0110] Example 6

[0111] The system of the equipment example is adopted, and naturally dried corn stalks are used as biomass raw materials, which are crushed into 3 mm particles with a water content of 10 wt%.

[0112] The first hopper was loaded with 500 g of catalytic cracking regeneration catalyst, and the second hopper was loaded with 25 g of biomass particles and 25 g of bio-oil.

[0113] The regenerated catalyst in the first hopper is heated to 700°C, and the screw feeds of the two hoppers are opened respectively, and the materials in the two hoppers are pushed into the rotary kiln 3, which has replaced the air with water vapor in advance, for pyrolysis reaction. Under the conditions of a pressure of 10Kpa(g) and a rotation speed of 2.0 rpm of the rotary kiln 3, the time for all the solid phase of the pyrolysis products to enter the settling chamber 3a is 60 minutes.

[0114] The gas phase of the pyrolysis product enters the condenser cooler 4 from the top of the settling chamber 3a, is cooled to a temperature of 60°C and enters the flash tower 5. At 10Kpa(g), the biogas at the top of the flash tower 5 is transferred to a gas collection bag for weighing and measurement; the bio-oil and water at the bottom of the flash tower 5 are separated and respectively put into a collection bottle for weighing and measurement; the solid phase of the pyrolysis product at the bottom of the settling chamber 3a is stripped at a temperature of 550°C by water vapor at 250°C and a pressure of 0.5MPa(g), cooled to 50°C, weighed and measured, and the weight of the original catalytic cracking catalyst is deducted to obtain the weight of the biochar. The obtained yield is shown in Table-6.

[0115] Table 6 Biomass + bio-oil pyrolysis yield

[0116] Cyclic pyrolysis product yield Yield, wt% Biogas 43.74％ Bio-oil 3.69％ Biochar 42.58％ water 10.00％ total 100.00％

[0117] The composition of biogas is analyzed. Biogas contains H 2 , C 1 ~C 4 of hydrocarbons.

[0118] The composition of bio-oil was analyzed. Bio-oil contains C 5 ~C 30 hydrocarbons and their oxygen-containing organic compounds.

[0119] Example 7

[0120] The system of the equipment example is adopted, and naturally dried corn stalks are used as biomass raw materials, which are crushed into 3 mm particles with a water content of 10 wt%.

[0121] The first hopper was loaded with 400 g of catalytic cracking regeneration catalyst, and the second hopper was loaded with 25 g of biomass particles and 25 g of bio-oil.

[0122] The regenerated catalyst in the first hopper is heated to 700°C, and the screw feeds of the two hoppers are opened respectively, and the materials in the two hoppers are pushed into the rotary kiln 3, which has replaced the air with water vapor in advance, for pyrolysis reaction. Under the conditions of pressure 8Kpa(g) and rotary kiln 3 speed of 1.5 rpm, the time for all the solid phase of the pyrolysis products to enter the settling chamber 3a is 90 minutes.

[0123] The gas phase of the pyrolysis product enters the condenser cooler 4 from the top of the settling chamber 3a, is cooled to a temperature of 50°C and enters the flash tower 5. At 8Kpa(g), the biogas at the top of the flash tower 5 is transferred to a gas collection bag for weighing and measurement; the bio-oil and water at the bottom of the flash tower 5 are separated and respectively put into collection bottles for weighing and measurement; the solid phase of the pyrolysis product at the bottom of the settling chamber 3a is stripped at a temperature of 500°C by water vapor at 300°C and a pressure of 0.5MPa(g), cooled to 50°C, weighed and measured, and the weight of the biochar is deducted from the weight of the original catalytic cracking catalyst. The obtained yield is shown in Table-7.

[0124] Table 7 Biomass + Bio-oil Pyrolysis Yield

[0125] Cyclic pyrolysis product yield Yield, wt% Biogas 43.98％ Bio-oil 2.82％ Biochar 43.20％ water 10.00％ total 100.00％

[0126] The composition of biogas is analyzed. Biogas contains H 2 , C 1 ~C 4 of hydrocarbons.

[0127] The composition of bio-oil was analyzed. Bio-oil contains C 5 ~C 30 hydrocarbons and their oxygen-containing organic compounds.

[0128] Example 8

[0129] The system of the equipment example is adopted, and naturally dried corn stalks are used as biomass raw materials, which are crushed into 3 mm particles with a water content of 10 wt%.

[0130] The first hopper was loaded with 400 g of catalytic cracking regeneration catalyst, and the second hopper was loaded with 25 g of biomass particles and 25 g of bio-oil.

[0131] The regenerated catalyst in the first hopper is heated to 700°C, and the screw feeds of the two hoppers are opened respectively, and the materials in the two hoppers are pushed into the rotary kiln 3, which has replaced the air with water vapor in advance, for pyrolysis reaction. Under the conditions of a pressure of 10Kpa(g) and a rotation speed of 1.0 rpm of the rotary kiln 3, the time for all the solid phase of the pyrolysis products to enter the settling chamber 3a is 120 minutes.

[0132] The gas phase of the pyrolysis product enters the condenser cooler 4 from the top of the settling chamber 3a, is cooled to a temperature of 50°C and enters the flash tower 5. At 10Kpa(g), the biogas at the top of the flash tower 5 is transferred to a gas collection bag for weighing and measurement; the bio-oil and water at the bottom of the flash tower 5 are separated and respectively put into collection bottles for weighing and measurement; the solid phase of the pyrolysis product at the bottom of the settling chamber 3a is stripped at a temperature of 500°C by water vapor at 350°C and a pressure of 0.5MPa(g), cooled to 50°C, weighed and measured, and the weight of the original catalytic cracking catalyst is deducted to obtain the weight of the biochar. The obtained yield is shown in Table-8.

[0133] Table 8 Biomass + Bio-oil Pyrolysis Yield

[0134] Cyclic pyrolysis product yield Yield, wt% Biogas 44.16％ Bio-oil 2.31％ Biochar 43.52％ water 10.00％ total 100.00％

[0135] The composition of biogas is analyzed. Biogas contains H 2 , C 1 ~C 4 of hydrocarbons.

[0136] The composition of bio-oil was analyzed. Bio-oil contains C 5 ~C 30 hydrocarbons and their oxygen-containing organic compounds.

[0137] The above are preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A biomass pyrolysis system in which a catalytic cracking unit is coupled with a rotary furnace, characterized in that: The biomass pyrolysis system includes a catalytic cracking settler, a catalytic cracking regenerator, a catalytic cracking fractionation tower, a rotary furnace, a condenser cooler and a flash tower; The catalytic cracking settler, catalytic cracking regenerator and rotary furnace are connected via pipelines; The rotary kiln has a settling chamber for gas-solid separation, and the settling chamber has a pyrolysis product gas phase outlet and a pyrolysis product solid phase outlet; The gas phase outlet of the pyrolysis product is connected to a condenser cooler, a flash tower, and a catalytic cracking fractionation tower in sequence; The solid phase outlet of the pyrolysis product is connected to a catalytic cracking settler.

2. The biomass pyrolysis system according to claim 1, characterized in that: The rotary kiln is a cylindrical structure, the central axis of the cylinder has an angle of 2 to 5 degrees with the horizontal line, and the cylinder rotates along the central axis; And / or, the flash tower is provided with 1 to 10 plates without overflow weir from the feed end to the top of the tower; And / or, a stirring device is provided at the bottom of the flash tower; And / or, the settling chamber has 1 to 10 groups of cyclone separators for gas-solid separation, and preferably the gas phase velocity at the inlet of the cyclone separator is 15 to 25 m / s.

3. A method for producing biogas using a catalytic cracking unit and a rotary furnace, characterized in that: The biomass and the regenerated catalyst from the catalytic cracking unit are subjected to catalytic pyrolysis reaction in a rotary furnace to obtain solid-phase pyrolysis products and gas-phase pyrolysis products; The gas phase pyrolysis product is flashed to obtain a gas phase product and a liquid phase product; The liquid phase is returned to the rotary kiln to cycle through the catalytic pyrolysis reaction; The gas phase is biogas.

4. The method according to claim 3, characterized in that The gas phase includes: H2, C1-C4 hydrocarbons; And / or, the liquid phase includes bio-oil and water; the bio-oil includes C5~C 30 Hydrocarbons and C5~C 30 of oxygen-containing organic compounds; The rotary kiln is a cylindrical structure, and the cylinder rotates along the central axis; preferably, the central axis of the cylinder has an angle of 2 to 5 degrees with the horizontal line; And / or, the gas phase enters the catalytic cracking fractionation tower of the catalytic cracking unit after flash evaporation; And / or, the solid phase pyrolysis product is sent to a catalytic cracking settler of a catalytic cracking unit.

5. The method according to claim 3 or 4, characterized in that: The regenerated catalyst comes from a catalytic cracking regenerator; and / or, the temperature of the regenerated catalyst is 650-750° C.; And / or, the biomass particles have a particle size of 1 to 10 mm and contain 0 to 20 wt% water; And / or, the amount of the regeneration catalyst is 5 to 10 times that of the biomass; And / or, when the liquid phase is present in the rotary kiln, the amount of the regeneration catalyst used is 5 to 10 times the total mass of the biomass and the liquid phase.

6. The method according to claim 3, 4 or 5, characterized in that: The reaction conditions in the rotary kiln include: a pressure of 5 to 10 KPa (g); and a catalytic pyrolysis reaction time of 60 to 120 minutes.

7. The method according to any one of claims 3 to 6, characterized in that: The conditions for gas-liquid separation of the flash evaporation include: temperature 40-60° C., pressure 5-10 KPa(g).

8. The method according to claim 4, characterized in that The conditions for the gas phase to enter the catalytic cracking distillation tower for distillation after flash evaporation and pressure increase include: temperature 40-60° C., pressure 0.10-0.25 MPa(g).

9. The method according to any one of claim 4, characterized in that: The solid phase pyrolysis product enters the catalytic cracking settler and is subjected to steam stripping. The conditions of the steam stripping include: the temperature of the solid phase pyrolysis product is 400-550°C and the pressure is 0.12-0.25MPa(g); the steam temperature is 250-350°C and the pressure is 0.3-0.8MPa(g), and the steam dosage is 3%-5% of the mass of the solid phase pyrolysis product.

10. The method according to claim 9, characterized in that The solid phase pyrolysis product is steam stripped in the catalytic cracking settler and then sent to the catalytic cracking regenerator to burn off the carbon deposits and is recycled as a regenerated catalyst.

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