A microwave continuous frequency modulation collaborative biomass directional depolymerization device and its usage method

Abstract

The present invention discloses a microwave continuous frequency modulation collaborative biomass directional depolymerization device and its usage method, belonging to the technical field of biomass resource utilization. The device includes a microwave continuous frequency modulation power supply, a microwave resonant cavity, a quartz tube reactor, and a product treatment device; a microwave feed port is provided on the microwave resonant cavity, and the microwave continuous frequency modulation power supply is connected to the microwave feed port; the quartz tube reactor is connected to an inert gas source, a biomass feed hopper is connected to the quartz tube reactor, a catalyst filling screen spacer is provided in the middle, an infrared thermal imager is provided above, and an infrared thermometer is provided at the catalyst filling screen spacer; the product treatment device includes a condensation system and a gas collection bag, the condensation system is arranged at the outlet of the quartz tube reactor, and the gas collection bag is arranged at the outlet of the condensation system. The present invention matches the microwave emission frequency with the intrinsic resonance frequencies of the three major components of biomass and the catalyst to achieve the goal of reducing the biomass cracking activation energy and realizing directional depolymerization.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomass resource utilization, and particularly relates to a microwave continuous frequency modulation collaborative biomass directional depolymerization device and a using method thereof. Background Art

[0002] Lignocellulosic biomass is an ideal alternative resource to fossil energy. As a large agricultural country, China is rich in forestry and agricultural biomass resources. According to the calculation in the "World Energy Outlook - China Special Report 2017", China can produce 300 million tons of crop straw waste and 300 million tons of forestry waste every year. Therefore, making full use of forestry and agricultural biomass resources is a feasible way to alleviate China's dependence on fossil energy. With the increasing depletion of fossil energy, it will surely affect the production and application of energy and fine chemicals in China, and further have a serious impact on people's daily lives. As an ideal alternative resource to fossil energy, efficiently utilizing rich lignocellulosic resources is of great significance to China's sustainable development.

[0003] Lignocellulose conversion technologies mainly include thermochemical conversion methods and biochemical methods, etc. At present, most of the biomass thermochemical conversions supply heat through traditional electric heating methods, which have disadvantages such as high heating energy consumption, slow heating speed, long heating time, and unstable temperature control. Lignocellulose is a complex macromolecule composed of cellulose, hemicellulose, and lignin connected by C-O bonds, C-C bonds, etc. In the process of its high-value utilization, due to the non-uniformity and difficult temperature control of traditional heating methods, it is very difficult to achieve the selective cleavage of C-O bonds and C-C bonds in lignocellulose macromolecules. Microwave heating has advantages such as low heating energy consumption, fast heating speed, and uniform heating. Therefore, microwave heating has received extensive attention in the utilization of lignocellulosic biomass. However, it is worth pointing out that although microwave heating shows better utilization prospects in many aspects such as lignocellulose liquefaction, pyrolysis, and gasification compared with traditional heating methods. However, currently, microwave heating generally uses a fixed frequency of 2.45 GHz. The main reason is that this microwave emission frequency is consistent with the intrinsic resonance frequency of water molecules, so as to achieve the "resonance" of water molecules to achieve a better heating effect. Since lignocellulosic biomass is composed of cellulose, hemicellulose, and lignin, its intrinsic frequency is different from that of water molecules. Therefore, conventional microwave heating may not be able to achieve the "resonance" bond breaking of the three components of molecules, and the catalyst is also composed of different active components and carriers, and its intrinsic frequency is also different from that of water molecules. Therefore, how to achieve the "resonance" of biomass components or catalyst active components with different intrinsic resonance frequencies to achieve the goal of biomass directional depolymerization has become a problem to be solved. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a microwave continuous frequency modulation coordinated biomass directional depolymerization device. Compared with the traditional microwave-assisted biomass pyrolysis device with a fixed emission frequency of 2.45GHz, the emission frequency of the microwave reactor of the present invention can match the intrinsic resonance frequency of the three components of biomass cellulose, hemicellulose and lignin molecules and the catalyst, so as to achieve the goal of reducing the activation energy of biomass cracking and achieving the directional depolymerization of the three major components of biomass. Another technical problem to be solved by the present invention is to provide a method for using the microwave continuous frequency modulation coordinated biomass directional depolymerization device, which has a simple structure and is easy to operate, and can achieve the directional catalytic depolymerization of the three major elements of biomass.

[0005] Technical solution: In order to solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] A microwave continuous frequency modulation coordinated biomass directional depolymerization device comprises a microwave continuous frequency modulation power supply, a microwave resonant cavity, a quartz tube reactor and a product processing device; the microwave resonant cavity is provided with a microwave feed port, and the microwave continuous frequency modulation power supply is connected to the microwave feed port; the quartz tube reactor is arranged in the microwave resonant cavity, the quartz tube reactor is connected to an inert gas source, a biomass feed hopper is connected to the quartz tube reactor, and a catalyst filling screen spacer is arranged in the middle; an infrared thermal imager is arranged above the quartz tube reactor for real-time monitoring of the cross-sectional temperature field distribution of the catalyst bed; an infrared thermometer is arranged at the catalyst filling screen spacer for detecting the temperature of the catalyst bed along the axial section of the quartz tube reactor; the product processing device comprises a condensation system and a gas collecting bag, the condensation system is arranged at the outlet of the quartz tube reactor, and the gas collecting bag is arranged at the outlet of the condensation system, the condensable product components after the reaction are condensed into liquid bio-oil through the condensation system, and the non-condensable parts are collected in the gas collecting bag.

[0007] The microwave continuous frequency modulation coordinated biomass directional depolymerization device, the product processing device also includes an online detection system, and the online detection system is arranged between the outlet of the quartz tube reactor and the condensation system.

[0008] The microwave continuous frequency modulation coordinated biomass directional depolymerization device and the infrared thermometer are non-contact type.

[0009] The microwave continuous frequency modulation coordinated biomass directional depolymerization device, the online detection system is a gas phase-mass spectrometer.

[0010] The microwave continuous frequency modulation coordinated biomass directional depolymerization device, the microwave continuous frequency modulation power supply is composed of different frequency modulation modules, the microwave emission frequency is continuously adjustable between 2.45~8GHz, the output power is freely adjusted between 200~500W; the frequency adjustment range is 0.1~1000MHz.

[0011] The microwave continuous frequency modulation collaborative biomass directional depolymerization device, the inner diameter of the quartz tube reactor is 10 mm.

[0012] The usage method of the above-mentioned microwave continuous frequency modulation collaborative biomass directional depolymerization device specifically includes the following steps:

[0013] 1) Uniformly arrange the catalyst on the catalyst filling screen spacer, and place the biomass raw material in the biomass feeding system; turn on the inert gas source to purge the quartz tube reactor, and maintain the inert gas atmosphere in the quartz tube reactor;

[0014] 2) Turn on the microwave continuous frequency modulation power supply. The microwave with continuously changing frequency enters the microwave resonance cavity through the microwave feed port. The catalyst bed layer arranged on the catalyst filling screen spacer continuously absorbs microwaves of different frequencies and gradually heats up. On the one hand, the temperature field change of the cross-section of the catalyst bed layer is monitored in real time through the thermal imager vertically arranged at the top of the quartz tube, and on the other hand, the temperature of the catalyst along the height cross-section of the quartz tube is also monitored in real time through the non-contact infrared thermometer. By observing the temperature of the catalyst, when the reaction temperature is reached; enter step 3);

[0015] 3) Turn on the biomass continuous feeding system, and uniformly feed the biomass raw material into the quartz tube reactor 4 for directional catalytic cracking reaction;

[0016] 4) After the reaction is completed, the product enters the condensation system at the outlet of the quartz tube reactor. The liquid product is collected after being condensed by the condensation system in the gaseous product, and the non-condensable gaseous product is collected in the gas collection bag for subsequent off-line analysis.

[0017] Beneficial effects: Compared with the existing technology, the advantages of the present invention include:

[0018] (1) Compared with the traditional microwave-assisted biomass pyrolysis device with a fixed emission frequency of 2.45 GHz, the emission frequency of the microwave reactor of the present invention can match the intrinsic resonance frequencies of the three components of biomass cellulose, hemicellulose, and lignin, so as to reduce the activation energy of biomass cracking and achieve the directional depolymerization of the three major components of biomass.

[0019] (2) The continuously variable microwave emission frequency of the present invention can achieve the resonance hotspots of more catalyst active components, achieving the purpose of selective catalysis. Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of the microwave continuous frequency modulation collaborative biomass directional depolymerization device. Detailed Embodiments

[0021] The present invention will be further illustrated below in conjunction with the accompanying drawings and specific implementation examples. It should be understood that these implementation examples are only used to illustrate the invention patent and not to limit the scope of the invention patent. After reading the invention patent, various equivalent modifications made by those skilled in the art to the invention patent fall within the scope defined by the appended claims of this application. Embodiment

[0022] A microwave continuous frequency modulation collaborative biomass directional depolymerization device is as Figure 1 shown. As can be Figure 1 seen from the figure, the device includes a microwave continuous frequency modulation power supply 1, a microwave resonant cavity 3, a quartz tube reactor 4, and a product treatment device; a microwave feed port 2 is provided on the microwave resonant cavity 3, and the microwave continuous frequency modulation power supply 1 is connected to the microwave feed port 2. The microwave continuous frequency modulation power supply 1 is composed of different frequency modulation modules, and the microwave emission frequency is continuously adjustable between 2.45 GHz and 8 GHz, and the output power can be freely adjusted between 200 W and 500 W; the frequency adjustment range is 0.1 MHz to 1000 MHz; the quartz tube reactor 4 is arranged in the microwave resonant cavity 3. The quartz tube reactor 4 is provided with a feed pipeline. One end of the feed pipeline is connected to the quartz tube reactor 4, and the other end is provided with a biomass feed hopper 7, and a catalyst filling screen spacer 5 is arranged in the middle; the quartz tube reactor 4 is connected to an inert gas source. An infrared thermal imager 6 is provided above the quartz tube reactor 4, and there is a certain distance between the two without contact, and the size of the distance can ensure that the cross-sectional temperature field distribution of the catalyst bed layer can be monitored in real time; a non-contact infrared thermometer 8 is provided at the catalyst filling screen spacer 5 for detecting the temperature of the catalyst bed layer along the axial cross-section of the quartz tube reactor; the product treatment device includes a condensation system 10, a gas collection bag, and an on-line detection system 9. The on-line detection system is a gas-phase mass spectrometer. The condensation system 10 is arranged at the outlet of the quartz tube reactor 4, and the on-line detection system is arranged between the condensation system 10 and the outlet of the quartz tube reactor 4. The on-line detection system can perform real-time on-line detection of the product; the gas collection bag is arranged at the outlet of the condensation system 10. The condensable product components after the reaction are condensed into liquid bio-oil by the condensation system 10, and the non-condensable part is collected in the gas collection bag.

[0023] The usage method of the above-mentioned microwave continuous frequency modulation collaborative biomass directional depolymerization device specifically includes the following steps:

[0024] 1) First, uniformly arrange the catalyst at the center of the quartz tube reactor, and place the biomass raw material in the biomass feeding system; turn on the inert carrier gas source to purge the quartz tube and maintain an inert gas atmosphere in the reaction tube;

[0025] 2) Subsequently, turn on the microwave continuous frequency modulation power supply 1. The microwave with continuously changing frequency enters the microwave resonance cavity 3 through the feed port. The catalyst bed layer arranged at the center of the quartz tube (inner diameter: 10 mm) continuously absorbs microwaves of different frequencies and gradually heats up. On the one hand, the temperature field change of the cross-section of the catalyst bed layer is monitored in real time by the thermal imager vertically arranged at the top of the quartz tube. On the other hand, the temperature of the catalyst along the height cross-section of the quartz tube is also monitored in real time by the non-contact infrared temperature measurement system. When the reaction temperature is reached, proceed to step 3);

[0026] 3) Turn on the biomass continuous feeding system, and uniformly feed the biomass raw materials into the quartz tube reactor 4 for catalytic cracking reaction to carry out the biomass directional catalytic depolymerization reaction;

[0027] 4) After the reaction is completed, the products are on-line detected by the on-line GC / MS detection system at the outlet of the quartz tube reactor to detect the composition of the reaction products in real time. The gaseous products after the reaction are condensed by the condensation system to collect the liquid products, and the non-condensable gaseous products are collected in the gas collection bag for subsequent off-line analysis.

Claims

1. A microwave continuous frequency modulation collaborative biomass directional depolymerization device, characterized in that, It includes a microwave continuous frequency modulation power supply (1), a microwave resonator cavity (3), a quartz tube reactor (4) and a product treatment device; a microwave feed port (2) is provided on the microwave resonator cavity (3), and the microwave continuous frequency modulation power supply (1) is connected to the microwave feed port (2); the quartz tube reactor (4) is arranged in the microwave resonator cavity (3), the quartz tube reactor (4) is connected to an inert gas source, a biomass feed hopper (7) is connected to the quartz tube reactor (4), and a catalyst filling screen spacer (5) is provided in the middle; an infrared thermal imager (6) is provided above the quartz tube reactor (4), and an infrared thermometer (8) is provided at the catalyst filling screen spacer (5); the product treatment device includes a condensation system and a gas collection bag, the condensation system (10) is arranged at the outlet of the quartz tube reactor (4), and the gas collection bag is arranged at the outlet of the condensation system (10); the microwave continuous frequency modulation power supply (1) is composed of different frequency modulation modules, the microwave emission frequency is 2.45 - 8 GHz, the frequency adjustment range is 0.1 - 1000 MHz, and the output power is 200 - 500 W.

2. The microwave continuous frequency modulation collaborative biomass directional depolymerization device according to claim 1, wherein The product treatment device further includes an on-line detection system (9), and the on-line detection system (9) is arranged between the outlet of the quartz tube reactor (4) and the condensation system (10).

3. The microwave continuous frequency modulation collaborative biomass directional depolymerization device according to claim 1, wherein The infrared thermometer (8) is non-contact type.

4. The microwave continuous frequency modulation collaborative biomass directional depolymerization device according to claim 2, characterized in that, The on-line detection system (9) is a gas-phase - mass spectrometry instrument.

5. The microwave continuous frequency modulation collaborative biomass directional depolymerization device according to claim 1, wherein The inner diameter of the quartz tube reactor (4) is 10 mm.

6. The usage method of the microwave continuous frequency modulation collaborative biomass directional depolymerization device according to any one of claims 1-5, characterized in that, Specifically, it includes the following steps: 1) Uniformly arrange the catalyst on the catalyst filling screen spacer, and place the biomass raw material in the biomass feeding system; turn on the inert carrier gas source to purge the quartz tube reactor, and maintain an inert gas atmosphere in the quartz tube reactor. 2) Turn on the microwave continuous frequency modulation power supply (1), the microwave with continuously changing frequency enters the microwave resonator cavity (3) through the microwave feed port, and the catalyst bed layer arranged on the catalyst filling screen spacer continuously absorbs microwaves of different frequencies and gradually heats up; detect the temperature of the catalyst through the thermal imager and the infrared thermometer, and when the reaction temperature is reached, enter step 3). 3) Turn on the biomass continuous feeding system, and uniformly feed the biomass raw material into the quartz tube reactor (4) for biomass directional catalytic cracking reaction. 4) After the reaction ends, the product enters the condensation system at the outlet of the quartz tube reactor, the liquid product is collected after being condensed by the condensation system in the gaseous product, and the non-condensable gaseous product is collected in the gas collection bag for subsequent off-line analysis.

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