A light-coupled microwave catalytic system and biomass pyrolysis device for biomass pyrolysis

Abstract

The present invention discloses a light-coupled microwave catalytic system for biomass pyrolysis. The light-coupled microwave catalytic system is a vacuum interlayer tube in which a light source is placed in the middle of the catalytic system, wherein the light source is a pulsed strong light source, and catalytic plates with catalytic activity are arranged around it. The catalytic plates use porous foam ceramic plates as carriers and are loaded with two or more metal oxide catalysts with catalytic activity. The photocatalytic activity is adjusted by adjusting the light source intensity, pulse width, pulse frequency and photocatalyst loading; the catalytic activity of the deoxygenation catalyst is adjusted by adjusting the porosity, skeleton strength, catalyst loading and microwave power of the porous foam ceramic. The present invention can be directly applied to steam upgrading after biomass pyrolysis, and the deoxygenation efficiency is improved by coupling the synergistic catalysis of "photocatalyst catalytic hydrogen release" with "metal oxide catalytic deoxygenation", reducing the production of tar, effectively improving the quality of pyrolysis bio-oil and biogas, increasing the service life, and reducing production costs.

Description

Technical Field

[0001] The invention relates to the field of photocatalysis and microwave catalysis, and in particular to a light-coupled microwave catalytic system and a biomass pyrolysis device applied to biomass pyrolysis. Background Art

[0002] The development and utilization of biomass resources is of great significance to alleviate the depletion of non-renewable resources and environmental problems. Thermochemical conversion, especially catalytic pyrolysis, is one of the important means of biomass conversion. The introduction of the catalytic system can effectively improve the quality of bio-oil and reduce the tar content in the gas. Commonly used catalysts include molecular sieve catalysts, metal oxide catalysts, and metal salt catalysts. Molecular sieve catalysts, such as ZSM-5, show excellent aromatization and deoxygenation capabilities; metal oxide catalysts, such as CaO and MgO, show good deoxygenation capabilities. At present, the easy passivation and deactivation of catalysts, short service life, and poor economic benefits are still one of the bottleneck problems restricting the widespread replacement of biomass for petroleum. Therefore, how to improve the catalytic performance and service life of the catalytic system is very important for the pyrolysis conversion of biomass to produce oil and gas. Polycyclic aromatic hydrocarbons are important precursors of catalyst coking and passivation. It is very important to reduce the production of polycyclic aromatic hydrocarbons or improve the degradation of polycyclic aromatic hydrocarbons.

[0003] Microwave heating has the advantages of uniform heating, no hysteresis effect, safety and no pollution. The catalysts currently used in microwave systems are mainly silicon carbide composite catalysts and biochar catalysts. Microwave heating can effectively reduce the amount of catalyst coking and extend the service life of the catalyst. Studies have shown that microwave catalytic quality improvement can significantly increase the hydrocarbon content in bio-oil, but this quality improvement is achieved at the expense of bio-oil yield. Photocatalysis is mainly used in the fields of water pollution purification, organic synthesis and photolysis of water to produce hydrogen. Commonly used photocatalysts include titanium dioxide, zinc oxide, tin oxide, zirconium dioxide and modified catalysts.

[0004] Photocatalytic technology has the advantages of mild reaction conditions, low energy consumption, and no secondary pollution. Taking TiO2 as an example, when TiO2 is exposed to light of a certain intensity, electron holes with strong redox ability can be generated on the surface of the TiO2 catalyst, thereby achieving catalysis. How to utilize this feature of photocatalysis, apply it to the field of biomass pyrolysis, combine it with microwave catalysis, adjust the catalytic quality improvement reaction pathway, reduce the production of tar, slow down the deactivation of catalysts, improve the quality of bio-oil while increasing the yield of bio-oil, and thus improve the efficiency of biomass pyrolysis conversion to oil is a direction worthy of research. Summary of the invention

[0005] The present invention provides a light-coupled microwave catalytic system suitable for the field of biomass pyrolysis, which has a simple process, combines the advantages of photocatalysis and microwave catalysis, and realizes efficient utilization of biomass resources.

[0006] The technical solution adopted by the present invention is:

[0007] A light-coupled microwave catalytic system for biomass pyrolysis comprises a quartz ring, a steam inlet, a light source, a vacuum interlayer tube, a catalytic plate, a microwave source and a steam outlet, wherein the light source is installed in the vacuum interlayer tube, a catalytic plate is installed outside the vacuum interlayer tube, the catalytic plate is installed in the interlayer of the quartz ring, the light source and the catalytic plate are separated by the vacuum interlayer tube, microwave sources are evenly arranged on the outer circle of the catalytic plate, and the catalytic plates are arranged around the light source at a certain angle.

[0008] The number of the catalytic plates is 30.

[0009] The catalytic plates are arranged at an angle of 12-180 degrees.

[0010] The microwave sources are arranged in a regular pentagonal shape, and may also be arranged in a regular triangular shape, a regular heptagonal shape, or a regular enneagonal shape.

[0011] When the pyrolysis gas passes through the catalytic system and contacts the catalyst, the catalytic quality improvement of the pyrolysis gas is achieved. The light source intensity, pulse width, pulse frequency and microwave power can all be adjusted.

[0012] The light source of the present invention is a xenon lamp.

[0013] The optically coupled microwave catalytic system of the present invention can be applied to biomass pyrolysis equipment by serial connection.

[0014] The catalytic plate of the present invention is prepared by loading a layer of deoxidation catalyst on the surface of the porous foam ceramic, and then dispersing a layer of photocatalyst on the outer layer of the deoxidation catalyst. The specific preparation method is as follows:

[0015] (1) Preparation of porous foam ceramics: SiC and TiC are mixed in proportion and then ball milled at a low speed for 0.5-2 hours to prepare ceramic aggregate. Ceramic aggregate is mixed with aluminum dihydrogen phosphate in a ratio of 1:1-4:1 and kaolin and deionized water are added to prepare slurry. After the slurry is stirred and mixed, it is kept at room temperature for 12-48 hours.

[0016] (2) Cut the polyurethane foam into the required shape and size, soak and rub it in 8%-20% sodium hydroxide solution for 1-3 hours, wash it, and then soak it in 0.5%-3% sodium carboxymethyl cellulose solution for 0.5-3 hours for use.

[0017] (3) The treated polyurethane foam is immersed in the slurry, and the excess slurry is removed by a rolling process to obtain a preform.

[0018] (4) The preform is dried at room temperature for 12-48 hours, transferred to an oven and dried at 65°C for 8-24 hours, and finally calcined in air to obtain a porous foam ceramic. The calcination process adopts a programmed temperature increase, first from room temperature to 200°C at 2°C / min, then from 200°C to 500°C at 1°C / min and maintained for 1 hour, and finally raised to the final temperature at 2°C / min and maintained for 2 hours.

[0019] (5) Preparation of deoxidation catalyst slurry: One or more of the seven raw materials of magnesium oxide, calcium oxide, zirconium oxide, aluminum oxide, strontium oxide, cerium oxide and nickel oxide are selected and compounded in proportion, and then mixed at a low speed in a ball mill for 0.5-2 hours, which is recorded as compound raw material 1. Based on 100 parts of compound raw material 1, 0.1-0.5 parts of polyvinyl alcohol, 0.5-4.0 parts of carboxymethyl cellulose and 0.2-1.0 parts of alkaline silica sol are weighed and dissolved in a certain amount of deionized water, and after mixing evenly, it is recorded as compound raw material 2. Compound raw material 1 and compound raw material 2 are mixed and stirred to prepare a deoxidation catalyst slurry.

[0020] (6) Immerse the porous foam ceramic in the deoxidation catalyst slurry, shake off the excess slurry and dry at room temperature for 12-24 hours. The dried embryo body is coated with slurry for the second time by slurry spraying method, shake off the excess slurry and dry at room temperature for 12-24 hours. The same as the second coating, multiple coatings can be performed until the embryo body is evenly coated with slurry. After the last coating, dry at room temperature for 12-24 hours, transfer to an oven and dry at 65°C for 8-24 hours to obtain a catalyst embryo body.

[0021] (7) Catalyst embryo calcination: The catalyst embryo was calcined by programmed temperature increase, first from room temperature to 300 °C at 2 °C / min, then from 300 °C to 500 °C at 1 °C / min and maintained for 1 hour, and finally raised to the final temperature at 2 °C / min and maintained for 2 hours.

[0022] (8)TiO 2 Precursor preparation: titanate butyl and anhydrous ethanol were mixed in a volume ratio of 1:1 and magnetically stirred for 0.5-1 hour, and an equal volume of 1 mol / L nitric acid solution was added and stirred for 1-2 hours to obtain TiO 2 Precursor.

[0023] (9) The fired catalyst embryo is placed on TiO 2 The precursor is placed in a static state for 2-5 hours, taken out and washed, naturally dried in the shade, and then air-dried at 70°C for 12-24 hours. After drying, calcined at 100-300°C for 1-2 hours to obtain the final catalytic plate.

[0024] Furthermore, the deionized water in step (1) is added at a slurry solid content of 60-80%.

[0025] Furthermore, the deionized water in step (5) is added at a slurry solid content of 40-60%.

[0026] Furthermore, the final temperature in step (4) is set at 1000-1500°C.

[0027] Furthermore, in step (7), the final temperature is set at 800-1200°C.

[0028] The present invention also provides a biomass pyrolysis device, which comprises the above-mentioned light-coupled microwave catalytic system.

[0029] The light-coupled microwave catalytic system for biomass pyrolysis described in the present invention can be directly applied to biomass catalytic pyrolysis and quality improvement, achieving the simultaneous progress of "photocatalyst catalytic hydrogen release" and "metal oxide catalytic deoxidation" under relatively mild conditions, reducing the production of tar, and effectively improving the quality of pyrolysis bio-oil and biogas. The catalytic system can achieve in-situ self-cleaning, increase service life, and reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of a catalytic plate of a light-coupled microwave catalytic system of the present invention.

[0031] Figure 2 It is a schematic diagram of the overall structure of the light-coupled microwave catalytic system of the present invention.

[0032] Figure 3 It is a cross-sectional view of the light-coupled microwave catalytic system of the present invention.

[0033] Figure 4 It is a schematic diagram of a flow chart of an embodiment of the present invention.

[0034] in, Figure 2 and Figure 3 1 is a steam inlet, 2 is a light source, 3 is a vacuum interlayer tube, 4 is a catalyst plate, 5 is a microwave source, and 6 is a steam outlet.

[0035] in, Figure 4 1 is a pyrolysis reaction chamber, 2 is a slag storage tank, 3 is a light-coupled microwave catalytic system, 4 is a cooling device, 5 is a liquid storage tank, 6 is a gas sampling port, 7 is a gas purification device, and 8 is a Roots blower. DETAILED DESCRIPTION

[0036] The present invention will be further described by the following examples in conjunction with the accompanying drawings, which are only used to explain the present invention but not to limit it.

[0037] like Figure 1-Figure 3As shown, a light-coupled microwave catalytic system for biomass pyrolysis includes a quartz ring, a steam inlet 1, a light source 2, a vacuum interlayer tube 3, a catalyst plate 4, a microwave source 5 and a steam outlet 6. The light source 2 is installed in the vacuum interlayer tube 3, a catalyst plate 4 is installed outside the vacuum interlayer tube 3, and the catalyst plate 4 is installed in the interlayer of the quartz ring. The light source 2 and the catalyst plate 4 are separated by the vacuum interlayer tube 3. Microwave sources 5 are evenly arranged on the outer circle of the catalyst plate 4, and the catalyst plates 4 are arranged around the light source 2 at a certain angle.

[0038] The number of the catalytic plates 4 is 30.

[0039] The catalytic plates are arranged at an angle of 12-180 degrees. The microwave sources 5 are arranged in a regular pentagonal shape, and can also be arranged in a regular triangular shape, a regular heptagonal shape, or a regular enneagonal shape.

[0040] When the pyrolysis gas passes through the catalytic system and contacts the catalyst, the catalytic quality improvement of the pyrolysis gas is achieved. The light source intensity, pulse width, pulse frequency and microwave power can all be adjusted.

[0041] The light source 2 is a xenon lamp.

[0042] More specifically, the catalytic plate is prepared by loading a layer of deoxidation catalyst on the surface of the porous foam ceramic, and then dispersing a layer of photocatalyst on the outer layer of the deoxidation catalyst. The specific preparation method is as follows:

[0043] (1) Preparation of porous foam ceramics: SiC and TiC are mixed in proportion and then ball milled at a low speed for 0.5-2 hours to prepare ceramic aggregate; the ceramic aggregate is mixed with aluminum dihydrogen phosphate in a ratio of 1:1-4:1 and kaolin and deionized water are added to prepare a slurry; the slurry is stirred and mixed and then stored at room temperature for 12-48 hours; deionized water is added at a slurry solid content of 60-80%.

[0044] (2) cutting the polyurethane foam into the required shape and size, soaking and kneading it in 8%-20% sodium hydroxide solution for 1-3 hours, washing it, and then soaking it in 0.5%-3% sodium carboxymethyl cellulose solution for 0.5-3 hours for use;

[0045] (3) The treated polyurethane foam is immersed in the slurry, and the excess slurry is removed by a roller pressing process to obtain a preform;

[0046] (4) The preform is dried at room temperature for 12-48 hours, transferred to an oven and dried at 65° C. for 8-24 hours, and finally calcined in air to obtain a porous foam ceramic; the calcination process adopts a programmed temperature increase, first from room temperature to 200° C. at 2° C. / min, then from 200° C. to 500° C. at 1° C. / min and maintained for 1 hour, and finally raised to the final temperature at 2° C. / min and maintained for 2 hours; the final temperature is set at 1000-1500° C.;

[0047] (5) Preparation of deoxidation catalyst slurry: one or more of seven raw materials including magnesium oxide, calcium oxide, zirconium oxide, aluminum oxide, strontium oxide, cerium oxide and nickel oxide are selected and compounded in proportion, and then mixed in a ball mill at a low speed for 0.5-2 hours, which is recorded as compound raw material 1; based on 100 parts of compound raw material 1, 0.1-0.5 parts of polyvinyl alcohol, 0.5-4.0 parts of carboxymethyl cellulose and 0.2-1.0 parts of alkaline silica sol are weighed and dissolved in a certain amount of deionized water, and the mixture is uniformly mixed and recorded as compound raw material 2; compound raw material 1 and compound raw material 2 are mixed and stirred to prepare deoxidation catalyst slurry; deionized water is added at a slurry solid content of 40-60%;

[0048] (6) Immersing the porous foam ceramic in the deoxidation catalyst slurry, shaking off the excess slurry and drying at room temperature for 12-24 hours; the dried embryo body is slurried for a second time by a slurry spraying method, shaking off the excess slurry and drying at room temperature for 12-24 hours; the same second slurrying can be performed for multiple times until the embryo body is evenly slurried; after the last slurrying, drying at room temperature for 12-24 hours, transferring to an oven and drying at 65° C. for 8-24 hours to obtain a catalyst embryo body;

[0049] (7) Catalyst embryo calcination: The catalyst embryo calcination adopts programmed temperature increase, first from room temperature to 300°C at 2°C / min, then from 300°C to 500°C at 1°C / min and maintained for 1 hour, and finally raised to the final temperature at 2°C / min and maintained for 2 hours; the final temperature is set at 800-1200°C;

[0050] (8)TiO 2 Precursor preparation: titanate butyl and anhydrous ethanol were mixed in a volume ratio of 1:1 and magnetically stirred for 0.5-1 hour, and an equal volume of 1 mol / L nitric acid solution was added and stirred for 1-2 hours to obtain TiO 2 Precursor;

[0051] (9) The fired catalyst embryo is placed on TiO 2 The precursor is allowed to stand for 2-5 hours, taken out and washed, naturally dried in the shade and then air-dried at 70°C for 12-24 hours; after drying, calcined at 100-300°C for 1-2 hours to obtain the final catalytic plate.

[0052] like Figure 4 As shown, a biomass pyrolysis device comprises a pyrolysis reaction chamber 1, a slag storage tank 2, a light-coupled microwave catalytic system 3, a cooling device 4, a liquid storage tank 5, a gas sampling port 6, a gas purification device 7 and a Roots blower 8. The steam inlet end of the light-coupled microwave catalytic system is connected to the gas outlet end of the pyrolysis reaction chamber, and the steam outlet end of the light-coupled microwave catalytic system is connected to the inlet end of the cooling device.

[0053] Example 1

[0054] In the step (1) of preparing the catalytic plate, the ratio of SiC to TiC is 1:0, the ball milling time is 1 hour, the ratio of ceramic aggregate to aluminum dihydrogen phosphate is 2:1, the slurry solid content is 80%, and the material trapping time is 24 hours; in the step (2), the sodium hydroxide concentration is 16%, the immersion time is 2 hours, the sodium carboxymethyl cellulose solution concentration is 2%, and the immersion time is 2 hours; in the step (4), the preform is dried at room temperature for 24 hours and then dried in an oven for 12 hours, and the final calcination temperature is 1200°C; in the step (5), the composite raw materials are magnesium oxide and aluminum oxide mixed in a ratio of 10:1 and ball milled. Grind for 1 hour, add 0.2 parts of polyvinyl alcohol, 0.5 parts of carboxymethyl cellulose and 0.5 parts of alkaline silica sol, and the solid content of the slurry is 55%; in step (6), the room temperature drying time after the foam ceramic is slurried is 18 hours each time, and the oven drying is 24 hours; in step (7), the final calcination temperature of the embryo body is set at 1200°C; in step (8), the magnetic stirring time is 1 hour, and after dropping an equal volume of 1 mol / L nitric acid solution, stirring is continued for 2 hours; in step (9), stand for 4 hours, the blast drying time is 12 hours, the calcination temperature is 300°C, and the calcination time is 1 hour.

[0055] Assemble the light source, the catalyst plate and the microwave source according to the attached figure to obtain the light-coupled microwave catalyst system.

[0056] The light-coupled microwave catalytic system is connected in series in the biomass pyrolysis system.

[0057] In this embodiment, soap stock is used as raw material, the pyrolysis temperature is 550°C, the microwave power of the optically coupled microwave catalytic system is 500W, and the light source intensity is 1mW / cm -2 The liquid in the storage tank and the gas from the gas sampling port were analyzed. The bio-oil yield was 68.31%, the content of monocyclic aromatic hydrocarbons in the bio-oil was 67.24%, the content of polycyclic aromatic hydrocarbons was 1.63%, and the tar content in the gas was 0.17 g / m 3 .

[0058] Example 2

[0059] In the step (1) of preparing the catalytic plate, the ratio of SiC to TiC is 1:0, the ball milling time is 1 hour, the ratio of ceramic aggregate to aluminum dihydrogen phosphate is 2:1, the slurry solid content is 80%, and the material trapping time is 24 hours; in the step (2), the sodium hydroxide concentration is 16%, the immersion time is 2 hours, the sodium carboxymethyl cellulose solution concentration is 2%, and the immersion time is 2 hours; in the step (4), the preform is dried at room temperature for 24 hours and then dried in an oven for 12 hours, and the final calcination temperature is 1200°C; in the step (5), the composite raw materials are magnesium oxide, calcium oxide and aluminum oxide mixed in a ratio of 5:5:1. The mixture is ball-milled for 1 hour, 0.2 parts of polyvinyl alcohol, 0.5 parts of carboxymethyl cellulose and 0.5 parts of alkaline silica sol are added, and the solid content of the slurry is 55%; in step (6), the room temperature drying time after the foam ceramic is slurried is 18 hours each time, and the oven drying is 24 hours; in step (7), the final calcination temperature of the embryo body is set at 1200°C; in step (8), the magnetic stirring time is 1 hour, and after an equal volume of 1 mol / L nitric acid solution is dropped, stirring is continued for 2 hours; in step (9), it is allowed to stand for 4 hours, the blast drying time is 12 hours, the calcination temperature is 300°C, and the calcination time is 1 hour.

[0060] Assemble the light source, the catalyst plate and the microwave source according to the attached figure to obtain the light-coupled microwave catalyst system.

[0061] The light-coupled microwave catalytic system is connected in series in the biomass pyrolysis system.

[0062] In this embodiment, soap stock is used as raw material, the pyrolysis temperature is 550°C, the microwave power of the optically coupled microwave catalytic system is 500W, and the light source intensity is 1mW / cm -2 The liquid in the storage tank and the gas from the gas sampling port were analyzed. The bio-oil yield was 65.91%, the content of monocyclic aromatic hydrocarbons in the bio-oil was 69.14%, the content of polycyclic aromatic hydrocarbons was 2.17%, and the tar content in the gas was 0.29 g / m 3 .

[0063] Example 3

[0064] In the step (1) of preparing the catalytic plate, the ratio of SiC to TiC is 1:0, the ball milling time is 1 hour, the ratio of ceramic aggregate to aluminum dihydrogen phosphate is 2:1, the slurry solid content is 80%, and the material trapping time is 24 hours; in the step (2), the sodium hydroxide concentration is 16%, the immersion time is 2 hours, the sodium carboxymethyl cellulose solution concentration is 2%, and the immersion time is 2 hours; in the step (4), the preform is dried at room temperature for 24 hours and then dried in an oven for 12 hours, and the final calcination temperature is 1200°C; in the step (5), the composite raw materials are magnesium oxide, calcium oxide and aluminum oxide mixed in a ratio of 5:5:1. The mixture is ball-milled for 1 hour, 0.2 parts of polyvinyl alcohol, 0.5 parts of carboxymethyl cellulose and 0.5 parts of alkaline silica sol are added, and the solid content of the slurry is 55%; in step (6), the room temperature drying time after the foam ceramic is slurried is 18 hours each time, and the oven drying is 24 hours; in step (7), the final calcination temperature of the embryo body is set at 1200°C; in step (8), the magnetic stirring time is 1 hour, and after an equal volume of 1 mol / L nitric acid solution is dropped, stirring is continued for 2 hours; in step (9), it is allowed to stand for 4 hours, the blast drying time is 12 hours, the calcination temperature is 300°C, and the calcination time is 1 hour.

[0065] Assemble the light source, the catalyst plate and the microwave source according to the attached figure to obtain the light-coupled microwave catalyst system.

[0066] The light-coupled microwave catalytic system is connected in series in the biomass pyrolysis system.

[0067] In this embodiment, rice straw is used as raw material, the pyrolysis temperature is 550°C, the microwave power of the optically coupled microwave catalytic system is 500W, and the light source intensity is 1mW / cm -2 The liquid in the storage tank and the gas from the gas sampling port were analyzed. The bio-oil yield was 54.81%, the content of monocyclic aromatic hydrocarbons in the bio-oil was 41.34%, the content of polycyclic aromatic hydrocarbons was 2.47%, and the tar content in the gas was 1.07 g / m 3 .

[0068] Example 4

[0069] In the step (1) of preparing the catalytic plate, the ratio of SiC to TiC is 1:0, the ball milling time is 1 hour, the ratio of ceramic aggregate to aluminum dihydrogen phosphate is 2:1, the slurry solid content is 80%, and the material trapping time is 24 hours; in the step (2), the sodium hydroxide concentration is 16%, the immersion time is 2 hours, the sodium carboxymethyl cellulose solution concentration is 2%, and the immersion time is 2 hours; in the step (4), the preform is dried at room temperature for 24 hours and then dried in an oven for 12 hours, and the final calcination temperature is 1200°C; in the step (5), the composite raw materials are zirconium oxide and calcium oxide mixed in a ratio of 20:1 and ball milled. Grind for 1 hour, add 0.2 parts of polyvinyl alcohol, 0.5 parts of carboxymethyl cellulose and 0.5 parts of alkaline silica sol, and the solid content of the slurry is 55%; in step (6), the room temperature drying time after the foam ceramic is slurried is 18 hours each time, and the oven drying is 24 hours; in step (7), the final calcination temperature of the embryo body is set at 1200°C; in step (8), the magnetic stirring time is 1 hour, and after dropping an equal volume of 1 mol / L nitric acid solution, stirring is continued for 2 hours; in step (9), stand for 4 hours, the blast drying time is 12 hours, the calcination temperature is 300°C, and the calcination time is 1 hour.

[0070] Assemble the light source, the catalyst plate and the microwave source according to the attached figure to obtain the light-coupled microwave catalyst system.

[0071] The light-coupled microwave catalytic system is connected in series in the biomass pyrolysis system.

[0072] In this embodiment, rice straw is used as raw material, the pyrolysis temperature is 550°C, the microwave power of the optically coupled microwave catalytic system is 500W, and the light source intensity is 1mW / cm -2 The liquid in the storage tank and the gas from the gas sampling port were analyzed. The bio-oil yield was 56.39%, the content of monocyclic aromatic hydrocarbons in the bio-oil was 38.61%, the content of polycyclic aromatic hydrocarbons was 1.37%, and the tar content in the gas was 0.93 g / m 3 .

[0073] The above only expresses the preferred embodiments of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications, improvements and substitutions can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A light-coupled microwave catalytic system for biomass pyrolysis, characterized in that: The invention comprises a quartz ring, a steam inlet, a light source, a vacuum interlayer tube, a catalyst plate, a microwave source and a steam outlet. The light source is installed in the vacuum interlayer tube, a catalyst plate is installed outside the vacuum interlayer tube, the catalyst plate is installed in the interlayer of the quartz ring, the light source and the catalyst plate are separated by the vacuum interlayer tube, microwave sources are evenly arranged on the outer circle of the catalyst plate, and the catalyst plate is arranged around the light source at a certain angle; the catalyst plate is prepared by loading a layer of deoxidation catalyst on the surface of the porous foam ceramic, and then dispersively loading a layer of photocatalyst on the outer layer of the deoxidation catalyst. The specific preparation method comprises the following steps: (1) Preparation of porous foam ceramics: SiC and TiC are mixed in proportion, and then the mixture is ball milled at a low speed for 0.5-2 hours to prepare ceramic aggregate; the ceramic aggregate is mixed with aluminum dihydrogen phosphate in a ratio of 1:1-4:1, and kaolin and deionized water are added to prepare slurry; the slurry is stirred and mixed, and then the mixture is stored at room temperature for 12-48 hours; (2) Cut the polyurethane foam into the required shape and size, soak and rub it in 8%-20% sodium hydroxide solution for 1-3 hours, wash it, and then soak it in 0.5%-3% sodium carboxymethyl cellulose solution for 0.5-3 hours for use; (3) The treated polyurethane foam is immersed in the slurry, and the excess slurry is removed by a roller pressing process to obtain a preform; (4) The preform is dried at room temperature for 12-48 hours, transferred to an oven and dried at 65°C for 8-24 hours, and finally calcined in air to obtain a porous foam ceramic; the calcination process adopts a programmed temperature increase, first from room temperature to 200°C at 2°C / min, then from 200°C to 500°C at 1°C / min and maintained for 1 hour, and finally raised to the final temperature at 2°C / min and maintained for 2 hours; (5) Preparation of deoxidation catalyst slurry: one or more of seven raw materials including magnesium oxide, calcium oxide, zirconium oxide, aluminum oxide, strontium oxide, cerium oxide and nickel oxide are selected and compounded in proportion, and then mixed in a ball mill at a low speed for 0.5-2 hours, which is recorded as compound raw material 1; based on 100 parts of compound raw material 1, 0.1-0.5 parts of polyvinyl alcohol, 0.5-4.0 parts of carboxymethyl cellulose and 0.2-1.0 parts of alkaline silica sol are weighed and dissolved in a certain amount of deionized water, and the mixture is uniformly mixed and recorded as compound raw material 2; compound raw material 1 and compound raw material 2 are mixed and stirred to prepare a deoxidation catalyst slurry; (6) Immersing the porous foam ceramic in the deoxidation catalyst slurry, shaking off the excess slurry and drying at room temperature for 12-24 hours; the dried embryo body is slurried for a second time by a slurry spraying method, shaking off the excess slurry and drying at room temperature for 12-24 hours; the same second slurrying can be repeated for multiple times until the embryo body is evenly slurried; after the last slurrying, drying at room temperature for 12-24 hours, transferring to an oven and drying at 65°C for 8-24 hours to obtain a catalyst embryo body; (7) Catalyst embryo calcination: The catalyst embryo was calcined by programmed temperature increase, first from room temperature to 300 °C at 2 °C / min, then from 300 °C to 500 °C at 1 °C / min and maintained for 1 hour, and finally raised to the final temperature at 2 °C / min and maintained for 2 hours; (8) Preparation of TiO2 precursor: titanate butyl and anhydrous ethanol were measured in a volume ratio of 1:1, mixed and magnetically stirred for 0.5-1 hour, and an equal volume of 1 mol / L nitric acid solution was added dropwise, and stirring was continued for 1-2 hours to obtain a TiO2 precursor; (9) The fired catalyst embryo is placed in a TiO2 precursor, left to stand for 2-5 hours, taken out and washed, naturally dried in the shade, and then air-dried at 70°C for 12-24 hours; after drying, calcined at 100-300°C for 1-2 hours to obtain the final catalyst plate.

2. According to claim 1, a light-coupled microwave catalytic system for biomass pyrolysis is characterized in that: The number of the catalytic plates is 30; the arrangement angle of the catalytic plates is 12-180 degrees.

3. The optically coupled microwave catalytic system for biomass pyrolysis according to claim 1, characterized in that: The microwave sources are arranged in a regular pentagonal shape, a regular trigonal shape, a regular heptagonal shape or a regular enneagonal shape.

4. The optically coupled microwave catalytic system for biomass pyrolysis according to claim 1, characterized in that: The light source is a xenon lamp.

5. The optically coupled microwave catalytic system for biomass pyrolysis according to claim 1, characterized in that: The optically coupled microwave catalytic system is applied to a biomass pyrolysis device by serial connection.

6. The optically coupled microwave catalytic system for biomass pyrolysis according to claim 1, characterized in that: The deionized water in step (1) is added according to the slurry solid content of 60-80%.

7. The optically coupled microwave catalytic system for biomass pyrolysis according to claim 1, characterized in that: The deionized water in step (5) is added according to the slurry solid content of 40-60%.

8. The optically coupled microwave catalytic system for biomass pyrolysis according to claim 1, characterized in that: The final temperature in step (4) is set at 1000-1500°C, and the final temperature in step (7) is set at 800-1200°C.

9. A biomass pyrolysis device, characterized in that: The device comprises the light-coupled microwave catalytic system described in any one of claims 1-8.

Images