Magnetothermocatalytic biomass gasification device and method

Abstract

The invention belongs to the field of combustion chemical engineering and materials, and particularly discloses a magnetic thermocatalysis biomass gasification device and method. The upper end and the lower end of a reactor are pressed, sealed and fixed through supporting tables and screws; the thermocouple extends into the reactor from a small hole in the top end of the reactor; a small hole is formed in a top cover of the reactor, and water vapor and nitrogen are introduced from the small hole; a coil connected with a high-frequency induction heater is arranged outside the reactor, and reactants in the reactor are heated by utilizing a magnetothermal effect; a plurality of layers of nickel nets are arranged in the reactor, and a mixture of biomass and a catalyst is arranged between every two adjacent layers of nickel nets; a gas outlet is formed in the bottom of the reactor and is sequentially connected with a gas washing bottle, a drying bottle and a gas bag. By adopting an electromagnetic induction heating technology, heat is directly generated and concentrated on the surfaces of the nickel net and the catalyst, and meanwhile, an alternating magnetic field is added to activate the catalyst, so that magnetic heat eddy current is generated on the surface of the catalyst, the catalytic activity is enhanced, and the chemical reaction rate at a hot spot is accelerated.

Description

Technical Field

[0001] The present invention relates to the technical fields of functional materials, energy conversion and environmental protection, and in particular to a device and method for magnetothermal catalytic biomass gasification. Background Art

[0002] As a renewable energy source, biomass has the advantages of abundant raw materials, renewable, low pollution and low carbon. Gasification is one of the common thermochemical conversion methods, which can convert biomass into combustible gases such as H2, CO and low molecular hydrocarbons. The development of biomass gasification technology is an important way to promote the clean and efficient conversion and utilization of biomass energy. However, at present, the traditional biomass electric heating gasification technology has problems such as limited heat and mass transfer, long gasification cycle time, high temperature, low energy utilization efficiency, poor gasification synthesis gas yield and quality. Therefore, it is urgent to develop a fast, energy-saving, safe and efficient biomass gasification technology. Since biomass absorbs heat during the reaction process, heat transfer is usually the main factor limiting the rate. In the traditional resistance heating process, heat needs to be transferred to the raw material bed through the reactor wall, the heat transfer rate is slow, and there is a certain amount of heat transfer loss. At the same time, there is a large temperature gradient between the catalysts in the material layer, which is easy to cause the catalyst to be carbonized and deactivated. Electromagnetic induction heating technology has the potential to overcome these problems with its characteristics of rapid and uniform heating, precise temperature control, and efficient energy utilization.

[0003] Although magnetic fields have shown significant effectiveness in biomass gasification catalytic reactions, their specific mechanism of action in the catalytic process still needs to be studied and explored in depth. Magnetic fields can not only provide driving force for magnetic and non-magnetic materials with built-in electric fields, but also affect the dynamic behavior of the reaction system and the activity of the catalyst through their unique physical properties. Reasonable design of reaction catalysts with magnetic field effects can maximize their catalytic performance and improve reaction efficiency and product quality. In the biomass gasification process, magnetic catalytic technology helps to improve the yield and selectivity of hydrogen while reducing the generation of by-products such as tar. However, the magnetic fields currently applied in catalytic reactions are mostly magnets or Helmholtz coils. The action distance of these magnetic field sources is relatively limited, which has certain limitations for large-scale industrial applications. In practical applications, further research and improvement of magnetic drive technology is needed to increase the action distance and intensity of the field so that the magnetic field can be more widely used in biomass magnetothermal catalytic reactions.

[0004] By deeply studying the specific mechanism of action of the magnetic field in the catalytic process and exploring the influence of the magnetic field on the catalyst activity and the dynamic behavior of the reaction, new ideas and methods can be provided for biomass magnetothermal catalytic reactions. The development of new magnetic catalysts and the optimization of the magnetic field application method will help improve the reaction efficiency, improve the product quality, and promote the application and promotion of biomass magnetothermal catalytic technology on an industrial scale. Summary of the invention

[0005] In view of the problems existing in the existing biomass gasification technology, such as limited heat and mass transfer, long gasification cycle, high temperature, low energy utilization efficiency, poor gasification synthesis gas yield and quality, the present invention proposes a magnetic thermal catalytic biomass gasification device and method. The purpose is to significantly improve the biomass conversion rate, synthesis gas yield and quality in the biomass gasification process through the gasification device. And effectively shorten the biomass gasification reaction cycle and improve energy utilization efficiency.

[0006] A magnetic thermal catalytic biomass gasification device comprises a reactor, wherein the reactor is a cylindrical quartz tube;

[0007] The upper and lower ends of the reactor are sealed and fixed with support platforms and screws;

[0008] The thermocouple extends from the small hole at the top of the reactor into the reactor to measure the real-time temperature inside the reactor;

[0009] The top cover of the reactor is provided with small holes, through which water vapor and nitrogen are introduced;

[0010] A coil connected to a high-frequency induction heater is provided outside the reactor to heat the reactants in the reactor using the magnetocaloric effect;

[0011] Multiple layers of nickel mesh are arranged in the reactor, and a mixture of biomass and catalyst is arranged between two adjacent layers of nickel mesh;

[0012] A gas outlet is arranged at the bottom of the reactor, and the gas outlet is connected to a gas washing bottle, a drying bottle and an air bag in sequence.

[0013] The nitrogen bottle is connected to the small hole through a flow meter and a valve; the water source inputs steam from the small hole through a water pump and a heating belt.

[0014] The high-frequency induction heater provides stable and uniform magnetic field, the magnetic field distribution is concentrated on the catalyst-biomass-water vapor interface, the magnetic field energy is concentrated on providing interface magnetic field and interface heating, and the heating temperature range is 450-650°C.

[0015] The catalyst is one or a mixture of two or more single metal or composite metal oxides;

[0016] Furthermore, the catalyst is one or a mixture of two or more of Ni3Fe, Ni, Fe, Mn, Cu, W, Mg, V, Mo, NiFe2O4, Ca2Fe2O5, Ca2Fe2O4, Fe2O3 or Fe3O4.

[0017] The biomass is at least one of straw, wood, fruit shell and bamboo.

[0018] The mass ratio of the biomass to the catalyst is 1:0.25-0.75.

[0019] The reactor is a hollow round tube made of silicon dioxide. When an alternating current of a specific frequency flows through the copper coil in the high-frequency induction heating machine, an alternating magnetic flux of the same frequency is generated. The porous nickel mesh and the magnetic catalyst are exposed to the alternating magnetic field to generate an induced potential, and current and eddy currents are formed on their surface to generate heat energy.

[0020] The nickel foam mesh has a porous skeleton structure, a large specific surface area and strong shaping ability, and can provide good support. The present invention further found that in order to improve the catalytic effect, the "sandwich" bed structure of alternating nickel mesh and reactants is used to help volatilize tar macromolecules during gasification for secondary cracking and deep conversion, thereby promoting the serial multi-stage conversion of biomass.

[0021] The magnetothermal catalytic biomass gasification method described in the present invention can achieve efficient conversion of biomass in a short time. The catalyst can provide a reaction site for accelerating the gasification of biomass. The magnetic induction activates the extremely fast heating and cooling of the magnetic catalyst, accelerates the gasification reaction rate at the hot spot, effectively shortens the biomass gasification reaction cycle, and reduces the biomass gasification reaction barrier. The magnetic field cooperates with the catalyst to deoxygenate the biomass gasification product, which is beneficial to the cracking of tar macromolecules and directional hydrogen production, and realizes efficient conversion and utilization of biomass under mild conditions. Preferably, the molar ratio of each metal in the multi-metal active phase is generally 1:1, and the ratio can be adjusted according to the product requirements.

[0022] Preferably, the grain size of the metal active particles is 10 to 30 nm.

[0023] Preferably, the specifications of the Ni mesh carrier include 10 to 80 ppi, a thickness range of 5 to 20 mm, and a diameter adapted to the reactor size.

[0024] The present invention also provides a method for magnetothermal catalytic biomass gasification, which uses the magnetothermal catalytic biomass gasification device described above, and the method comprises: transporting biomass, catalyst and water vapor to a gasification reactor, heating the reactants by magnetothermal effect, capturing oxygen ions in the intermediate products of biomass gasification, and participating in the activation and dissociation of water molecules, completing the replacement of electrons and adsorbed oxygen and the cracking of water vapor to produce hydrogen, thereby achieving deep deoxygenation and directional gasification of the products.

[0025] The specific steps include:

[0026] 1) Mix the biomass and the catalyst evenly in a mortar;

[0027] 2) The mixture obtained in step 1) is evenly laid on a nickel mesh having a magnetic response effect, and is alternately stacked with the nickel mesh to form a "sandwich" structure;

[0028] 3) loading the "sandwich" structure bed material obtained in step 2) into the reactor, sealing and debugging the device;

[0029] 4) Turn on the water pump to allow water to flow into the bypass, and turn on the heating belt;

[0030] 5) After the water in the pipeline is completely vaporized, close the bypass, open the reactor air inlet valve, and allow the water vapor and nitrogen (40 mL / min) to mix evenly and then flow into the magnetic-thermal reactor;

[0031] 6) simultaneously with step 5), a high-frequency induction heater is turned on to energize the coil and excite the magnetic field, so that the biomass in the reactor is almost completely converted in a short time;

[0032] Preferably, the temperature of the magnetic thermal catalytic biomass steam gasification process is 450-650°C;

[0033] Preferably, the heat required in the magnetothermal catalytic biomass steam gasification process is provided by an external magnetic field.

[0034] Preferably, the external magnetic field input power is 450-900W.

[0035] Preferably, the water vapor flow rate required for the reaction is 0-0.03 mL / min;

[0036] 7) The gas at the reactor outlet passes through two gas washing bottles filled with acetone and a drying bottle filled with anhydrous calcium sulfate powder, and is collected by an air bag, and the components and concentrations are detected by gas chromatograph;

[0037] 8) After the acetone is removed from the liquid product by a rotary evaporator, the liquid product is ultrasonically mixed with anhydrous sodium sulfate powder to remove water, thereby obtaining bio-oil.

[0038] The present invention, through the magnetic thermal catalytic biomass gasification device and method, can not only efficiently convert biomass into hydrogen-rich synthesis gas, but also break through the kinetic limitations in the reaction process, increase the gas production rate, and achieve a dual increase in the production and quality of synthesis gas.

[0039] The technical effects of the present invention are as follows:

[0040] (1) The present invention innovatively applies electromagnetic induction heating technology to biomass gasification reaction, and designs and builds a set of magnetic thermal catalytic biomass gasification reaction device, such as Figure 2As shown, heat is directly induced on the magnetic material and quickly generated without heating the entire reactor, overcoming the problems of slow heating / cooling rate, uneven heating, and low energy efficiency. The electromagnetic induction heating method accelerates the chemical reaction rate at the local surface hot spots of the magnetic material, effectively shortens the biomass gasification reaction cycle, reduces the reaction barrier, and allows the biomass to undergo gasification reaction at a lower temperature, at least 100°C lower than conventional reactions.

[0041] (2) The magnetic field synergistic catalyst enhanced biomass gasification method proposed in the present invention can effectively improve the biomass conversion rate. The magnetic field can activate the magnetic catalyst, change its electronic spin properties, and synergistically enhance the deoxygenation and quality improvement of the biomass gasification product, effectively reducing the tar content. The specific principle is as follows Figure 3 In the process of high-temperature chemical reactions, uneven heating and temperature overshoot can easily lead to catalyst deactivation due to carbon deposition and sintering, making it difficult to maintain its cyclic stability. The use of magnetic field synergistic catalysis can effectively solve the above problems.

[0042] (3) The "sandwich" bed material structure designed by the present invention, such as Figure 4 As shown in the figure, the heat and mass transfer efficiency is improved. The nickel mesh and the reactants are stacked alternately, which helps the tar macromolecules volatilized during the gasification process to undergo secondary cracking and deep conversion. As a medium for electromagnetic induction heating, the nickel mesh can quickly respond and convert a small amount of input energy into high-temperature thermal energy; as a catalyst for biomass gasification reaction, the nickel mesh can catalyze tar cracking and increase the yield of synthesis gas. At the same time, in the reducing atmosphere of the biomass gasification reaction, the nickel mesh will not be oxidized and can be recycled. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A schematic diagram of the device for evaluating the performance of the magnetic thermal catalytic biomass gasification of the present invention;

[0044] Figure 2 It is a schematic diagram of the device for evaluating the performance of the magnetic thermal catalytic biomass gasification of the present invention;

[0045] Figure 3 This is a schematic diagram of the magnetic response of a material excited by an energized coil according to the present invention;

[0046] Figure 4 This is a schematic diagram of a "sandwich" structure bed material composed of a porous nickel mesh carrier and a catalyst-biomass of the present invention;

[0047] Figure 5 This is a schematic diagram of a magnetothermal catalytic biomass gasification reactor of the present invention;

[0048] Figure 6 This is an exploded view of the magnetothermal catalytic biomass gasification reactor of the present invention;

[0049] Figure 7The ratio of three-phase products of biomass magnetothermal catalytic gasification under different Ni / Fe molar ratios in the catalyst in the embodiment;

[0050] Figure 8 The proportion of three-phase products of biomass gasification under different electromagnetic induction heating powers of the present invention in the embodiment;

[0051] Fig. 9 The gas concentration and synthesis gas yield of biomass magnetothermal catalytic gasification under different Ni / Fe molar ratios in the catalyst in the embodiment;

[0052] Fig.10 The biomass gasification gas concentration and synthesis gas yield under different electromagnetic induction heating powers in the embodiment;

[0053] Fig.11 The low calorific value and energy utilization efficiency of biomass magnetothermal catalytic gasification synthesis gas at different Ni / Fe molar ratios in the catalyst in the embodiment;

[0054] Fig.12 The low calorific value and energy utilization efficiency of biomass gasification synthesis gas under different electromagnetic induction heating powers in the embodiment. DETAILED DESCRIPTION

[0055] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and technical solutions.

[0056] like Figure 1 , Figure 2 , Figure 5 and Figure 6 As shown, a magnetic thermal catalytic biomass gasification device is characterized in that it includes a reactor 1, and the reactor 1 is a cylindrical quartz tube; the upper and lower ends of the reactor 1 are sealed and fixed by a support platform 2 and screws;

[0057] The thermocouple 3 extends from the small hole at the top of the reactor 1 into the reactor 1 to measure the real-time temperature in the reactor 1; the top cover of the reactor 1 is provided with a small hole 4, through which water vapor and nitrogen are introduced;

[0058] The reactor 1 is provided with a coil 6 connected to a high-frequency induction heater 12, which utilizes the magnetocaloric effect to heat the reactants in the reactor 1. Figure 3 ;like Figure 4 A plurality of layers of nickel mesh 7 are arranged in the reactor 1, and a mixture of biomass and catalyst 8 is arranged between two adjacent layers of nickel mesh 7; a gas outlet 5 is arranged at the bottom of the reactor 1, and the gas outlet 5 is connected to a washing bottle 9, a drying bottle 10 and an air bag 11 in sequence.

[0059] The nitrogen bottle 13 is connected to the small hole 4 through a flow meter 14 and a valve; the water source inputs steam from the small hole 4 through a water pump 15 and a heating belt 16.

[0060] The specific embodiments of the magnetic thermal catalytic biomass gasification method of the present invention are as follows:

[0061] 1) Mix the biomass and the catalyst evenly in a mortar;

[0062] 2) The mixture 8 obtained in step 1) is evenly laid on the nickel mesh 7 having a magnetic response effect, and is alternately stacked with the nickel mesh 7 to form a "sandwich" structure;

[0063] 3) loading the "sandwich" structure bed material obtained in step 2) into the reactor 1, sealing and debugging the device;

[0064] 4) Turn on the water pump 15 to allow water to flow into the bypass, and turn on the heating belt 16;

[0065] 5) After the water in the pipeline is completely vaporized, close the bypass and open the air inlet valve of reactor 1 to allow the water vapor and nitrogen to mix evenly and then flow into reactor 1;

[0066] 6) At the same time as step 5), the high-frequency induction heater 12 is turned on to energize the coil 6 and excite the magnetic field, so that the biomass in the reactor 1 is almost completely converted in a short time;

[0067] Preferably, the temperature of the magnetic thermal catalytic biomass steam gasification process is 450-650°C;

[0068] Preferably, the heat required in the magnetothermal catalytic biomass steam gasification process is provided by an external magnetic field.

[0069] Preferably, the external magnetic field input power is 450-900W.

[0070] Preferably, the water vapor flow rate required for the reaction is 0-0.03 mL / min;

[0071] 7) The gas discharged from the gas outlet 5 of the reactor 1 passes through two gas washing bottles 9 filled with acetone and a drying bottle 10 filled with anhydrous calcium sulfate powder, and is collected by an air bag 11, and the components and concentrations are detected by a gas chromatograph;

[0072] 8) After the acetone is removed from the liquid product by a rotary evaporator, the liquid product is ultrasonically mixed with anhydrous sodium sulfate powder to remove water, thereby obtaining bio-oil.

[0073] Example 1

[0074] 1) Mix the biomass and the catalyst evenly in a mortar (the molar ratio of Ni-Fe in the catalyst is 1:1);

[0075] 2) The mixture obtained in step 1) is evenly laid on a nickel mesh with a magnetic response effect (specification: 20 ppi, thickness: 5 mm, diameter: 48 mm), and alternately stacked with the nickel mesh to form a "sandwich" structure;

[0076] 3) loading the "sandwich" structure bed material obtained in step 2) into the reactor, sealing and debugging the device;

[0077] 4) Turn on the water pump to allow water to flow into the bypass, and turn on the heating belt (the water flow rate is set to 0.02 mL / min);

[0078] 5) After the water in the pipeline is completely vaporized, close the bypass, open the reactor air inlet valve, and allow the water vapor and nitrogen (40 mL / min) to mix evenly and then flow into the magnetic-thermal reactor;

[0079] 6) At the same time as step 5), a high-frequency induction heater is turned on, the coil is energized and the magnetic field is excited, the electromagnetic induction heating power is 755 W, the reaction temperature is maintained at 530° C., and the biomass in the reactor is almost completely converted in a short time;

[0080] 7) The gas at the reactor outlet passes through two gas washing bottles filled with acetone and a drying bottle filled with anhydrous calcium sulfate powder, and is collected by a gas bag. The components and concentrations are detected by gas chromatography. The yield of gasification synthesis gas and the concentrations of various components in the product gas are measured. The results are shown in Figure 7-Figure 12 .

[0081] 8) After the acetone is removed from the liquid product by a rotary evaporator, the liquid product is ultrasonically mixed with anhydrous sodium sulfate powder to remove water, thereby obtaining bio-oil.

[0082] Example 2

[0083] Compared with Example 1, the only difference is that the molar ratio of Ni-Fe elements in the catalyst is 1:2.

[0084] 1) Mix the biomass and the catalyst evenly in a mortar (the molar ratio of Ni-Fe in the catalyst is 1:2);

[0085] 2) The mixture obtained in step 1) is evenly laid on a nickel mesh with a magnetic response effect (specification: 20 ppi, thickness: 5 mm, diameter: 48 mm), and alternately stacked with the nickel mesh to form a "sandwich" structure;

[0086] 3) loading the "sandwich" structure bed material obtained in step 2) into the reactor, sealing and debugging the device;

[0087] 4) Turn on the water pump to allow water to flow into the bypass, and turn on the heating belt (the water flow rate is set to 0.02 mL / min);

[0088] 5) After the water in the pipeline is completely vaporized, close the bypass, open the reactor air inlet valve, and allow the water vapor and nitrogen (40 mL / min) to mix evenly and then flow into the magnetic-thermal reactor;

[0089] 6) At the same time as step 5), a high-frequency induction heater is turned on, the coil is energized and the magnetic field is excited, the electromagnetic induction heating power is 755 W, the reaction temperature is maintained at 530° C., and the biomass in the reactor is almost completely converted in a short time;

[0090] 7) The gas at the reactor outlet passes through two gas washing bottles filled with acetone and a drying bottle filled with anhydrous calcium sulfate powder, and is collected by a gas bag. The components and concentrations are detected by gas chromatography. The yield of gasification synthesis gas and the concentrations of various components in the product gas are measured. The results are shown in Figure 7-Figure 12 .

[0091] 8) After the acetone is removed from the liquid product by a rotary evaporator, the liquid product is ultrasonically mixed with anhydrous sodium sulfate powder to remove water, thereby obtaining bio-oil.

[0092] Example 3

[0093] Compared with Example 1, the only difference is that the molar ratio of Ni-Fe elements in the catalyst is 2:1.

[0094] 1) Mix the biomass and the catalyst evenly in a mortar (the molar ratio of Ni-Fe in the catalyst is 2:1);

[0095] 2) The mixture obtained in step 1) is evenly laid on a nickel mesh with a magnetic response effect (specification: 20 ppi, thickness: 5 mm, diameter: 48 mm), and alternately stacked with the nickel mesh to form a "sandwich" structure;

[0096] 3) loading the "sandwich" structure bed material obtained in step 2) into the reactor, sealing and debugging the device;

[0097] 4) Turn on the water pump to allow water to flow into the bypass, and turn on the heating belt (the water flow rate is set to 0.02 mL / min);

[0098] 5) After the water in the pipeline is completely vaporized, close the bypass, open the reactor air inlet valve, and allow the water vapor and nitrogen (40 mL / min) to mix evenly and then flow into the magnetic-thermal reactor;

[0099] 6) At the same time as step 5), a high-frequency induction heater is turned on, the coil is energized and the magnetic field is excited, the electromagnetic induction heating power is 755 W, the reaction temperature is maintained at 530° C., and the biomass in the reactor is almost completely converted in a short time;

[0100] 7) The gas at the reactor outlet passes through two gas washing bottles filled with acetone and a drying bottle filled with anhydrous calcium sulfate powder, and is collected by a gas bag. The components and concentrations are detected by gas chromatography. The yield of gasification synthesis gas and the concentrations of various components in the product gas are measured. The results are shown in Figure 7-Figure 12 .

[0101] 8) After the acetone is removed from the liquid product by a rotary evaporator, the liquid product is ultrasonically mixed with anhydrous sodium sulfate powder to remove water, thereby obtaining bio-oil.

[0102] Example 4

[0103] Compared with Example 1, the only difference is that the electromagnetic induction heating power is 455W.

[0104] 1) Mix the biomass and the catalyst evenly in a mortar (the molar ratio of Ni-Fe in the catalyst is 1:1);

[0105] 2) The mixture obtained in step 1) is evenly laid on a nickel mesh with a magnetic response effect (specification: 20 ppi, thickness: 5 mm, diameter: 48 mm), and alternately stacked with the nickel mesh to form a "sandwich" structure;

[0106] 3) loading the "sandwich" structure bed material obtained in step 2) into the reactor, sealing and debugging the device;

[0107] 4) Turn on the water pump to allow water to flow into the bypass, and turn on the heating belt (the water flow rate is set to 0.02 mL / min);

[0108] 5) After the water in the pipeline is completely vaporized, close the bypass, open the reactor air inlet valve, and allow the water vapor and nitrogen (40 mL / min) to mix evenly and then flow into the magnetic-thermal reactor;

[0109] 6) At the same time as step 5), a high-frequency induction heater is turned on, the coil is energized and the magnetic field is excited, the electromagnetic induction heating power is 455W, the reaction temperature is maintained at 480°C, and the biomass in the reactor is almost completely converted in a short time;

[0110] 7) The gas at the reactor outlet passes through two gas washing bottles filled with acetone and a drying bottle filled with anhydrous calcium sulfate powder, and is collected by a gas bag. The components and concentrations are detected by gas chromatography. The yield of gasification synthesis gas and the concentrations of various components in the product gas are measured. The results are shown in Figure 7-Figure 12 .

[0111] 8) After the acetone is removed from the liquid product by a rotary evaporator, the liquid product is ultrasonically mixed with anhydrous sodium sulfate powder to remove water, thereby obtaining bio-oil.

[0112] Example 5

[0113] Compared with Example 1, the only difference is that the electromagnetic induction heating power is 884W.

[0114] 1) Mix the biomass and the catalyst evenly in a mortar (the molar ratio of Ni-Fe in the catalyst is 1:1);

[0115] 2) The mixture obtained in step 1) is evenly laid on a nickel mesh with a magnetic response effect (specification: 20 ppi, thickness: 5 mm, diameter: 48 mm), and alternately stacked with the nickel mesh to form a "sandwich" structure;

[0116] 3) loading the "sandwich" structure bed material obtained in step 2) into the reactor, sealing and debugging the device;

[0117] 4) Turn on the water pump to allow water to flow into the bypass, and turn on the heating belt (the water flow rate is set to 0.02 mL / min);

[0118] 5) After the water in the pipeline is completely vaporized, close the bypass, open the reactor air inlet valve, and allow the water vapor and nitrogen (40 mL / min) to mix evenly and then flow into the magnetic-thermal reactor;

[0119] 6) At the same time as step 5), a high-frequency induction heater is turned on, the coil is energized and the magnetic field is excited, the electromagnetic induction heating power is 884W, the reaction temperature is maintained at 580°C, and the biomass in the reactor is almost completely converted in a short time;

[0120] 7) The gas at the reactor outlet passes through two gas washing bottles filled with acetone and a drying bottle filled with anhydrous calcium sulfate powder, and is collected by a gas bag. The components and concentrations are detected by gas chromatography. The yield of gasification synthesis gas and the concentrations of various components in the product gas are measured. The results are shown in Figure 7-Figure 12 .

[0121] 8) After the acetone is removed from the liquid product by a rotary evaporator, the liquid product is ultrasonically mixed with anhydrous sodium sulfate powder to remove water, thereby obtaining bio-oil.

[0122] Comparative Example 1

[0123] Compared with Example 1, the only difference is that only Ni is used as the catalyst active component.

[0124] 1) Mix the biomass and the catalyst evenly in a mortar (the catalyst only contains Ni);

[0125] 2) The mixture obtained in step 1) is evenly laid on a nickel mesh with a magnetic response effect (specification: 20 ppi, thickness: 5 mm, diameter: 48 mm), and alternately stacked with the nickel mesh to form a "sandwich" structure;

[0126] 3) loading the "sandwich" structure bed material obtained in step 2) into the reactor, sealing and debugging the device;

[0127] 4) Turn on the water pump to allow water to flow into the bypass, and turn on the heating belt (the water flow rate is set to 0.02 mL / min);

[0128] 5) After the water in the pipeline is completely vaporized, close the bypass, open the reactor air inlet valve, and allow the water vapor and nitrogen (40 mL / min) to mix evenly and then flow into the magnetic-thermal reactor;

[0129] 6) At the same time as step 5), a high-frequency induction heater is turned on, the coil is energized and the magnetic field is excited, the electromagnetic induction heating power is 755 W, the reaction temperature is maintained at 530° C., and the biomass in the reactor is almost completely converted in a short time;

[0130] 7) The gas at the reactor outlet passes through two gas washing bottles filled with acetone and a drying bottle filled with anhydrous calcium sulfate powder, and is collected by a gas bag. The components and concentrations are detected by gas chromatography. The yield of gasification synthesis gas and the concentrations of various components in the product gas are measured. The results are shown in Figure 7-Figure 12 .

[0131] 8) After the acetone is removed from the liquid product by a rotary evaporator, the liquid product is ultrasonically mixed with anhydrous sodium sulfate powder to remove water, thereby obtaining bio-oil.

[0132] Comparative Example 2

[0133] Compared with Example 1, the only difference is that only Fe is used as the catalyst active component.

[0134] 1) Mix the biomass and the catalyst evenly in a mortar (the catalyst only contains Fe);

[0135] 2) The mixture obtained in step 1) is evenly laid on a nickel mesh with a magnetic response (specification: 20 ppi, thickness: 5 mm, diameter: 48 mm), and alternately stacked with the nickel mesh to form a "sandwich" structure;

[0136] 3) loading the "sandwich" structure bed material obtained in step 2) into the reactor, sealing and debugging the device;

[0137] 4) Turn on the water pump to allow water to flow into the bypass, and turn on the heating belt (the water flow rate is set to 0.02 mL / min);

[0138] 5) After the water in the pipeline is completely vaporized, close the bypass, open the reactor air inlet valve, and allow the water vapor and nitrogen (40 mL / min) to mix evenly and then flow into the magnetic-thermal reactor;

[0139] 6) At the same time as step 5), a high-frequency induction heater is turned on, the coil is energized and the magnetic field is excited, the electromagnetic induction heating power is 755 W, the reaction temperature is maintained at 530° C., and the biomass in the reactor is almost completely converted in a short time;

[0140] 7) The gas at the reactor outlet passes through two gas washing bottles filled with acetone and a drying bottle filled with anhydrous calcium sulfate powder, and is collected by a gas bag. The components and concentrations are detected by gas chromatography. The yield of gasification synthesis gas and the concentrations of various components in the product gas are measured. The results are shown in Figure 7-Figure 12 .

[0141] 8) After the acetone is removed from the liquid product by a rotary evaporator, the liquid product is ultrasonically mixed with anhydrous sodium sulfate powder to remove water, thereby obtaining bio-oil.

[0142] Comparative Example 3

[0143] Compared with Example 1, the only difference is that only foamed Ni mesh is used as a carrier, and no metal catalyst active phase is used.

[0144] 1) The biomass is evenly laid on a nickel mesh with magnetic response (specification: 20ppi, thickness: 5mm, diameter: 48mm), and alternately stacked with the nickel mesh to form a "sandwich" structure;

[0145] 2) loading the "sandwich" structure bed material obtained in step 1) into the reactor, sealing and debugging the device;

[0146] 3) Turn on the water pump to allow water to flow into the bypass, and turn on the heating belt (the water flow rate is set to 0.02 mL / min);

[0147] 4) After the water in the pipeline is completely vaporized, close the bypass, open the reactor air inlet valve, and allow the water vapor and nitrogen (40 mL / min) to mix evenly and then flow into the magnetic-thermal reactor;

[0148] 5) At the same time as step 5), a high-frequency induction heater is turned on, the coil is energized and the magnetic field is excited, the electromagnetic induction heating power is 755 W, the reaction temperature is maintained at 530° C., and the biomass in the reactor is almost completely converted in a short time;

[0149] 6) The gas at the reactor outlet passes through two gas washing bottles filled with acetone and a drying bottle filled with anhydrous calcium sulfate powder, and is collected by an air bag. The components and concentrations are detected by gas chromatography. The yield of gasification synthesis gas and the concentrations of various components in the product gas are measured. The results are shown in Figure 7-Figure 12 .

[0150] 7) After the acetone is removed from the liquid product by a rotary evaporator, the liquid product is ultrasonically mixed with anhydrous sodium sulfate powder to remove water, thereby obtaining bio-oil.

[0151] Comparative Example 4

[0152] Compared with Example 1, the only difference is that the heating method is changed to resistance wire heating.

[0153] 1) Mix the biomass and the catalyst evenly in a mortar (the molar ratio of Ni-Fe in the catalyst is 1:1);

[0154] 2) placing the mixture obtained in step 1) into a quartz tube, using a resistance wire heating furnace, setting the heating rate to be consistent with electromagnetic induction heating, and sealing and debugging the device;

[0155] 3) Turn on the water pump to allow water to flow into the bypass, and turn on the heating belt (the water flow rate is set to 0.02 mL / min);

[0156] 4) After the water in the pipeline is completely vaporized, close the bypass, open the reactor air inlet valve, and allow the water vapor and nitrogen (40 mL / min) to mix evenly and then flow into the magnetic-thermal reactor;

[0157] 5) simultaneously with step 4), the resistance heating furnace is started, the reaction temperature is maintained at 530° C., and the gasification time is consistent with the electromagnetic induction heating reaction time;

[0158] 6) The gas at the reactor outlet passes through two gas washing bottles filled with acetone and a drying bottle filled with anhydrous calcium sulfate powder, and is collected by an air bag. The components and concentrations are detected by gas chromatography. The yield of gasification synthesis gas and the concentrations of various components in the product gas are measured. The results are shown in Figure 7-Figure 12 .

[0159] 7) After the acetone is removed from the liquid product by a rotary evaporator, the liquid product is ultrasonically mixed with anhydrous sodium sulfate powder to remove water, thereby obtaining bio-oil.

[0160] Table 1 Gasification test results of step 6 of the embodiment and the comparative example

[0161]

[0162] Compared with the working condition without catalyst (Comparative Example 3), the addition of Ni-Fe alloy significantly improves the yield of gasification synthesis gas and the utilization rate of hydrogen atoms. Among them, the working condition of adding Ni alone (Comparative Example 1) has the highest syngas yield, which can reach 44.10mmol / g biomass. The addition of Ni helps to break the CC bonds of macromolecules in biomass, promotes the balance of methane dry reforming reaction and water gas shift reaction to move towards hydrogen production. Since the CH4 content in biomass gasification synthesis gas is low, the gasification result under the synergistic effect of multiple factors is reflected in the increase of CO2 and H2 production in synthesis gas. Adding Fe alone helps the production of bio-oil. When both are added at the same time, the utilization rate of hydrogen atoms and the yield of synthesis gas are improved to varying degrees. It may be due to the synergistic effect of Ni and Fe elements in the process of magnetothermal catalytic biomass gasification, which produces higher reaction activity and stronger sintering resistance, which helps to improve the biomass conversion rate. It can be seen from Examples 1, 2, and 3 that, when the total amount of catalyst is the same, the catalyst with a Ni-Fe element molar ratio of 1:1 has the best performance and the highest production of syngas and H2, so this element ratio catalyst is selected for subsequent experiments. It can be seen from Examples 1, 4, and 5 that with the increase of input power, the reaction temperature gradually increases, and the syngas yield increases linearly. Compared with traditional resistance wire heating (Comparative Example 4), magnetic heat synergistic biomass gasification can effectively increase the syngas production.

Claims

1. A magnetic thermal catalytic biomass gasification device, characterized in that: The invention comprises a reactor (1), wherein the reactor (1) is a cylindrical quartz tube; The upper and lower ends of the reactor (1) are sealed and fixed by using a support platform (2) and screws; A thermocouple (3) extends from a small hole at the top of the reactor (1) into the reactor (1) to measure the real-time temperature in the reactor (1); The top cover of the reactor (1) is provided with a small hole (4), and water vapor and nitrogen are introduced through the small hole (4); The reactor (1) is provided with a coil (6) connected to a high-frequency induction heater (12) outside the reactor to heat the reactants in the reactor (1) by utilizing the magnetocaloric effect; A plurality of layers of nickel mesh (7) are arranged in the reactor (1), and a mixture (8) of biomass and catalyst is arranged between two adjacent layers of nickel mesh (7); The bottom of the reactor (1) is provided with a gas outlet (5), and the gas outlet (5) is sequentially connected to a gas washing bottle (9), a drying bottle (10) and an air bag (11).

2. The magnetic thermal catalytic biomass gasification device according to claim 1, characterized in that: The nitrogen bottle (13) is connected to the small hole (4) through a flow meter (14) and a valve; the water source inputs steam from the small hole (4) through a water pump (15) and a heating belt (16).

3. The magnetic thermal catalytic biomass gasification device according to claim 1, characterized in that: The high-frequency induction heater (12) provides stable and uniform magnetic field distribution concentrated on the catalyst-biomass-water vapor interface, and the magnetic field energy is concentrated on providing interface magnetic field and interface heating, and the heating temperature range is 450-650°C.

4. The magnetic thermal catalytic biomass gasification device according to claim 1, characterized in that: The catalyst is one or a mixture of two or more single metal or composite metal oxides.

5. The magnetic thermal catalytic biomass gasification device according to claim 1, characterized in that: The catalyst is one or a mixture of two or more of Ni3Fe, Ni, Fe, Mn, Cu, W, Mg, V, Mo, NiFe2O4, Ca2Fe2O5, Ca2Fe2O4, Fe2O3 or Fe3O4.

6. The magnetic thermal catalytic biomass gasification device according to claim 1, characterized in that: The biomass is at least one of straw, wood, fruit shell and bamboo.

7. The magnetic thermal catalytic biomass gasification device according to claim 1, characterized in that: The mass ratio of the biomass to the catalyst is 1:0.25-0.

75.

8. A method for magnetic thermal catalytic biomass gasification, characterized in that: Using a magnetic thermal catalytic biomass gasification device as claimed in any one of claims 1 to 7, the method comprises: Biomass, catalyst and water vapor are transported to a gasification reactor (1), and the reactants are heated by magnetocaloric effect to capture oxygen ions in the biomass gasification intermediate products, while participating in the activation and dissociation of water molecules, completing the replacement of electrons and adsorbed oxygen and the production of hydrogen by water vapor cracking, thereby achieving deep deoxygenation and directional gasification of the products.

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