CN112526033B - Performance evaluation system and method for thermochemical fuel production based on high temperature reactor - Google Patents

Abstract

The system comprises a gas pretreatment part for inputting gas required by reaction, a tubular furnace part for placing reactants and carrying out high-temperature thermochemical fuel reaction, a vacuumizing part before the reaction, a condenser part for condensing mixed gas, a gas-liquid separator part for separating gas and liquid, a dryer part for preventing water vapor from entering a chromatograph and drying, and a gas component detection part. The invention is specially designed for preparing hydrogen or carbon monoxide by high-temperature water cracking or carbon dioxide, the fuel gas generation rate is more stable, no by-product is generated, and the purity is high; a steam generating unit is designed independently aiming at hydrogen production by high-temperature thermochemical cracking water, and measures such as heating and heat preservation are taken for a pipeline through which high-temperature steam flows, so that the steam is prevented from being liquefied.

Description

Performance evaluation system and method for thermochemical fuel production based on high temperature reactor

technical field

The invention relates to a performance evaluation system and method thereof, in particular to a performance evaluation system and method for thermochemical fuel production based on a high-temperature reactor.

Background technique

Today's energy structure is undergoing a major transformation. Fossil fuels are increasingly being replaced by various renewable energy sources. Among them, wind energy and solar energy are the best performers, and solar energy contains huge heat. The solar energy on the earth is very abundant. Every year The energy absorbed by the earth is about 120,000 TW, which is nearly 4 orders of magnitude higher than the annual energy consumption of 15 TW. At present, all countries in the world are studying the utilization of solar energy radiated to the ground, among which the utilization of heat storage is the most impressive, and the technology of photovoltaic power generation is produced accordingly. This technology converts solar energy into electrical energy and then uses it for power supply. However, as materials such as cobalt and rare earth elements in energy storage batteries, there is not much storage on the earth, and this technology is difficult to be widely used.

From the perspective of reaction principle, the simplest conversion method is to use the heat generated by concentrated solar energy to decompose water or carbon dioxide directly at ultra-high temperature (usually greater than 1700 ° C) to obtain hydrogen and carbon monoxide. Using this technology, the energy level can be relatively low The solar energy is converted into high-grade chemical energy, etc., so as to realize the maximum utilization of renewable energy. It is manifested as the decomposition of thermochemical water and carbon dioxide by concentrated solar energy. CO and H ₂ can be obtained through this technology, and then converted into liquid hydrocarbon fuel by Fischer-Tropsch method, so that solar energy is converted into chemical energy to replace fossil fuels. However, this method has high requirements on the reaction temperature and poses great challenges to the physical and chemical properties of the material.

Direct use of concentrators to concentrate solar energy for heat supply has relatively high conditions to reach the decomposition temperature of water or carbon dioxide, and the reaction conversion efficiency is not high. Therefore, a two-step high-temperature thermochemical decomposition of related oxides to obtain fuel gas has been studied. The first step is to reduce the oxide at a higher temperature to release oxygen, and the second step is to pass water or carbon dioxide at a lower temperature to generate the corresponding gaseous fuel through an oxidation reaction. And the present invention is invented based on such a principle, reducing oxygen-deficient oxides at high temperature, and then reacting with water vapor or carbon dioxide in a tube furnace to generate hydrogen or carbon monoxide.

The current methods for evaluating the performance of high-temperature thermochemical fuel-making reactions are usually on a laboratory scale. An experimental scheme and a corresponding set of systems are designed, and then the system is used to evaluate the performance of high-temperature thermochemical fuel-making reactions. The scheme has the following deficiencies:

(1) The pipeline path is single, and only one fuel gas such as hydrogen or carbon monoxide can be prepared, and multiple fuels cannot be prepared, and the reaction temperature of most experimental systems is not high enough to carry out high-temperature thermochemical cracking oxide fuel experiments.

(2) Pipelines, etc. are exposed to the air, and they are not fixed well, so there are problems such as potential safety hazards and inconvenient operation; during the operation of the reaction, it is confusing and not well marked.

(3) Most of them are cracking reaction systems for preparing fuel gas from gaseous raw materials. Because the system of cracking water to produce hydrogen is more complicated, few people consider it, and it is difficult to comprehensively evaluate the experimental performance of high-temperature thermochemical fuel production reactions.

In addition, a prior art of the applicant (application number: CN2019106489368) discloses a system and method for evaluating the performance of thermochemical hydrogen production reaction based on a solar concentrating simulator. The method includes a raw material input part, an evaporator/preheating device, micro multi-channel reactor, condenser, chromatograph, flow piping system and solar concentration simulator; the raw material input part includes a liquid input part and a gas input part, and the liquid input part and the gas input part are in the evaporator/pre Convergence in front of the heater; the evaporator/preheater is a large chamber tank heated by electricity or solar energy, and a spray device is installed inside; the preheater initially heats the gas at the same time; the micro multi-channel reactor and the evaporator/ The preheater and the condenser are connected through pipelines; the chromatograph is used to detect the composition of the mixed gas generated; the solar concentration simulator includes a high-power xenon lamp light source and an elliptical high-reflectivity reflector. Although this document is also a kind of evaluation system and method thereof, the hardware equipments such as condenser, chromatograph, flow pipeline system etc. that it adopts are identical with the present invention, but because this prior art and the technical scheme of the present invention and to solve Therefore, those skilled in the art cannot apply it to the present invention to further solve the technical problems to be solved by the present invention, that is, this document does not provide any "enlightenment" or "combined enlightenment" to achieve the present invention. purpose of the invention.

Contents of the invention

The invention proposes a method for evaluating the reaction performance of thermochemical fuel production based on a high-temperature reactor. Its purpose is to overcome the shortcomings in the background technology, provide a general system for all high-temperature thermochemical fuel production reactions within 700-1600 ° C, and at the same time ensure the overall safety and reliability of the system, easy to operate, and can also be used for the reaction of the obtained The remaining reactants and mixed gas components are analyzed comprehensively and accurately, and the specific performance of the high-temperature thermochemical fuel system can be evaluated more comprehensively.

Its technical scheme is as follows:

A reaction performance evaluation system for thermochemical fuel production based on a high-temperature reactor, including a gas pretreatment part, a high-temperature reactor part, a flow control and pipeline part, a condensation part, a drying part, and a gas component detection part;

The gas pretreatment includes two parts: the direct input part of the gas and the part where the original phase is converted from liquid to gas input; the direct input part of the gas is provided with carrier gas/protection gas or reaction gas by the gas cylinder, and the gas is fully mixed in the mixer 12 After entering the main pipeline, the liquid phase conversion gas phase is carried by the carrier gas into the main pipeline.

The high-temperature reactor part: the main pipe is connected with the high-temperature reactor 24 to carry out corresponding chemical reactions; the main body is a high-temperature tube furnace with electric heating or infrared heating, in which corundum tubes and the like that withstand high temperatures are designed inside to accommodate the reaction The size of the tube furnace matches the size of the used corundum tube, etc.; the reactor is connected with a vacuum pump 31 and a condenser 10.

The flow control and pipeline part: one-way switches are set in each control part of the pipeline; corresponding one-way valves, vacuum gauges, gas flow meters, thermocouples, etc. are configured in different pipeline sections; the types of pipelines include but are not limited to high temperature and corrosion resistant Stainless steel tubes, PTFE tubes, etc., and the connection parts are fastened with stainless steel to ensure airtightness.

The condensing part: the condenser 10 and the high-temperature reactor 24 are connected by 3mm stainless steel pipes, and the steel pipes are protected and insulated, and a one-way valve is arranged on the steel pipes to prevent the high-temperature gas from flowing back into the reactor; a vacuum gauge is equipped behind the one-way valve , used for real-time monitoring of the pressure of the mixed gas after the reaction; the bottom of the condenser 10 is connected with the gas-liquid separator 26 through a stainless steel pipe to collect the condensed liquid substance.

The drying part: the condensed gas is passed into the dryer 27, the main body is one to two drying columns, and the pipeline in front of the dryer is equipped with a one-way valve to prevent the mixed gas from flowing backward; the dryer is connected with a one-way switch and gas flow rate A total of 17 are connected.

The gas component detection part: the dried mixed gas is connected to the gas chromatograph 5 through the gas flow meter 17, to detect the type and rate of the generated mixed gas, and to evaluate the overall fuel performance of the experimental system, and at the same time Equipped with a computer to receive and process data from the chromatograph and flowmeters.

The present invention also discloses an evaluation method of a thermochemical fuel production reaction performance evaluation system based on a high temperature reactor, the steps of which include:

Step 1: Power on the test bench, check that the status of each component is normal, check that the status of all switching instruments is correct, put the catalyst material used into the corundum crucible and put it into the pipeline of the high-temperature reactor, after filling the catalyst, place the plug , Tighten the quick-connect flange behind the reactor pipe; turn on the circulating water pump, and pass in cooling water.

Step 2: Turn on the vacuum pump to vacuumize the pipeline, then open the gas cylinder containing the carrier gas/protection gas, use the pressure reducing valve to adjust the pressure, use the gas flow meter to adjust the gas flow, and blow the various pipe parts of the test bench system Sweep; turn on the high-temperature tube furnace, adjust the corresponding program to control the heating rate to a suitable temperature, and at the same time continue to feed the carrier gas/protection gas, the catalyst undergoes a reduction reaction in the high-temperature thermochemical fuel production to generate oxygen, and time control the first step The time for the reduction reaction to proceed;

Step 3: Control the tube furnace program to cool down, open the gas cylinder with the reaction gas, control the pressure through the pressure reducing valve, control the flow rate of the reaction gas through the gas flow meter, and cooperate with the introduction of the carrier gas/protection gas, the two gases After passing through the mixer, it enters the main pipeline, and then enters the reactor, where it undergoes a second-step fuel oxidation reaction with the material; if the reactant is in the gas phase at room temperature, it can be controlled by a high-pressure gas cylinder connected to a gas flow meter, if the reactant is For water, it is necessary to control the generation of water vapor through the water vapor generation unit of the gas pretreatment part to participate in the reaction.

Step 4: The unreacted gas oxides, as well as the hydrogen or carbon monoxide generated by the reaction, are driven by the carrier gas/protective gas, and then enter the condenser after leaving the reactor, where the mixed gas is cooled to reduce the gas temperature and prevent Damage to the instrument; liquid reactants at normal temperature are condensed into liquid and separated and collected in the gas-liquid separator, and other mixed gases enter the dryer to be dried;

Step 5: The dried mixed gas at normal temperature enters the gas chromatograph through the gas flow meter, and its components are detected and analyzed in detail, and the data obtained are processed by computer to evaluate the performance of the entire high-temperature thermochemical cracking oxide fuel system and efficiency.

The type of carrier gas/protection gas can be selected according to the specific chemical reaction, including but not limited to nitrogen, argon, etc.; raw materials that are gaseous reactants at room temperature include but not limited to carbon dioxide, methane, and liquid at room temperature The reactant is generally water; the fuel gas generated is carbon monoxide or hydrogen; the temperature range of the high-temperature reactor is 700 degrees Celsius to 1600 degrees Celsius;

Beneficial effect:

(1) The thermochemical reaction temperature that can be carried out is higher, and it is specially designed for high-temperature cracking of water or carbon dioxide to produce hydrogen or carbon monoxide, and the rate of fuel gas production is more stable without by-products, and the purity is high;

(2) By fixing different parts of the experimental devices in the form of a cabinet as a whole, all wires and other lines are placed behind the cabinet, which is easy to operate, solves potential safety hazards, and ensures stable experiments and stable data generation;

(3) Separately design the water vapor generation unit for high-temperature thermochemical cracking of water to produce hydrogen, and add heat tracing and insulation measures for the pipelines through which high-temperature water vapor flows to prevent water vapor from liquefying.

Description of drawings

Fig. 1 is an explanatory diagram of the structure of the thermochemical fuel production reaction performance evaluation system based on the high temperature reactor of the present invention;

Fig. 2 is a time-varying diagram of the amount of hydrogen produced in a high-temperature cracking water hydrogen production reaction in Example 1 of the high-temperature reactor-based thermochemical fuel production reaction performance evaluation system of the present invention.

Fig. 3 is a time-varying diagram of the amount of carbon monoxide produced in a high-temperature cracking carbon dioxide to carbon monoxide reaction in Example 2 of the high-temperature reactor-based thermochemical fuel production reaction performance evaluation system of the present invention.

Explanation of reference signs:

1, 23, 25- vacuum gauge, 2, 3, 4, 6, 7, 11, 14, 15, 16, 19, 21, 22, 30- switch, 5- gas chromatograph, 8- evaporator, 9- Safety valve, 10-condenser, 12-mixer, 13-thermocouple, 17, 18, 20-flow meter, 24-high temperature reactor, 26-gas-liquid separator, 27-dryer, 28, 29-high pressure Cylinder, 31 - vacuum pump.

Detailed ways

In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

The invention discloses a thermochemical fuel reaction performance evaluation system based on a high-temperature reactor, which includes a gas pretreatment part, a high-temperature reactor part, a flow control and pipeline part, a condensation part, a drying part, and a gas component detection part;

The gas pretreatment part: the direct input part of the gas and the part where the original phase is converted from liquid to gas input. The direct input part of the gas is provided with carrier gas/protective gas or reaction gas by the gas cylinder, and the carrier gas is used as a gas source to drive the whole experiment The gas of the system flows, and can be used as a protective gas to purge the air and oxygen in the reactor to protect the reaction from being disturbed by impurity gases. Generally, inert gases such as nitrogen, argon, etc. are selected; used in high-temperature thermochemical fuel production The reaction gas is generally carbon dioxide, methane, etc. The reaction gas and carrier gas/protection gas can be controlled by the gas flow meter and mixed evenly in the mixer, and then enter the main pipeline for corresponding reactions. The pressure reducing valve of the gas cylinder is connected to the 6mm pipe and the experimental The PTFE tube of the platform is connected to the gas flow meter; the liquid phase conversion gas phase part is generally converted from water to water vapor. This part is composed of a syringe pump and a water vapor generator placed up and down in the cabinet. The two cooperate to realize water vapor. Precise control of the amount of generation, the generated water vapor is carried by the carrier gas/protection gas into the main pipeline.

The high-temperature reactor part: the main body is a custom-made ultra-high temperature tube furnace, the tube furnace is 950mm long, 500mm wide, and 1230mm high, of which the heating section is 300mm long, using single temperature control, the constant temperature zone is 150mm long, and the middle constant temperature zone The temperature required for the reaction can be effectively controlled to ensure the progress of the reaction; the furnace is made of 1900-type alumina polycrystalline fiber board, which has the advantages of small shrinkage, low thermal conductivity, good heat preservation effect, durability and energy saving; The corundum tube with an outer diameter of 40mm and a length of 1000mm is used to place the reactants. The corundum material can withstand high temperature conditions and will not react with reactants and catalyst materials. The design with an inner diameter of 30mm can not only ensure the normal progress of the reaction , It is also convenient for the installation of the fast flange when sealing the front and rear; the heating furnace and the stainless steel pipe are connected in the form of a quick flange with a diameter of 40mm and a sealing ring, which is convenient for operation and ensures the tightness of the joint, and the valve close to the high temperature part, etc. All use 316L steel material to ensure the high temperature corrosion resistance of the parts; the operating temperature of the tube furnace is less than or equal to 1700°C, the heating rate below 300°C is 3-5°C min, and the heating rate above 300°C is maintained at 5-8°C /min, the cooling rate is generally less than or equal to 10°C/min, such a heating and cooling rate can reduce the damage to the heating furnace due to the rapid temperature difference change, and can ensure the smooth progress of the reaction; Vacuum operation and removal of impurity gases.

The flow control and pipeline part: set a one-way switch in each control part of the pipeline to control the switch state required for the corresponding reaction. The material of the switch includes but is not limited to 316L steel; different pipeline sections are equipped with corresponding one-way valves to prevent gas backflow damage Components, equipped with a vacuum gauge to monitor the pressure of the pipeline section in real time, and equipped with a quick pressure relief valve to prevent accidents due to excessive gas pressure in the pipeline; the types of pipelines include but are not limited to high temperature and corrosion resistant stainless steel pipes, polytetrafluoroethylene pipes, etc.; gas All the main pipes of the pretreatment part are made of 6mm stainless steel pipes, while the pipes of the condenser dryer part are made of 3mm stainless steel pipes, and the connecting parts are fastened with stainless steel, fast flanges, etc. For example, the pipe connecting the steam generator and the main pipe is equipped with heating tape to maintain the temperature of the water vapor, and this part of the pipe is treated with multi-layer insulation, including the pipe plus a heater to ensure the temperature of the water vapor to prevent the water vapor from entering the high temperature reaction. Accidents and destruction reactions caused by liquefaction before the device, and these insulation materials can effectively isolate the temperature and prevent people from being injured by touching; all the small instruments and other components mentioned above are fixed by fixing methods including but not limited to stainless steel clamps, nylon cable ties, etc. On the cabinet placed horizontally on the experimental table, it is easy to operate and can effectively prevent the occurrence of safety accidents; all flow meters, check valves, etc. are connected to the main pipeline with stainless steel pipes including but not limited to 3mm and 6mm; in the high temperature reactor The last pipe section and the pipe section before the gas enters the gas flow meter are equipped with thermocouples to monitor the temperature in real time and grasp the temperature status of these two important pipe sections.

The condensing part: includes a condenser and a gas-liquid separator that are cooled by circulating water. The condenser is connected to the high-temperature reactor with a 3mm stainless steel tube. The stainless steel tube is used for protection and heat insulation. The high-temperature gas flows back into the reactor; a vacuum gauge is equipped behind the one-way valve to monitor the pressure of the mixed gas after the reaction in real time, and a quick pressure relief valve is equipped at the inlet switch of the condenser to prevent the pressure of the high-temperature gas in the tube from being too high during the experiment. Large accidents occur; the condenser adopts a circulating water cooling method, the circulating condensed water flows through the spiral stainless steel tube containing high-temperature gas, the condensed water flows from bottom to top, and is connected to the external cold water source through a plastic water pipe with an inner diameter of 2mm; the condenser The lower part is connected to the gas-liquid separator through a 3mm stainless steel pipe to collect the condensed liquid substance. The bottom of the gas-liquid separator is equipped with a valve. After the experiment is over, the collected liquid can be discharged through the control valve.

The drying part: the main body is one or two drying columns, and the pipeline in front of the dryer is equipped with a one-way valve to prevent the mixed gas from flowing backward; the drying column is easy to disassemble and easy to replace, and the ingredients in the drying column include but are not limited to calcium sulfate, calcium chloride , to completely absorb the water vapor in the mixed gas to prevent the water vapor from entering the chromatograph and damage the instrument; the dryer is connected with a one-way switch connected to the gas flow meter to realize real-time monitoring of the flow rate of the reacted mixed gas before entering the chromatograph .

The gas component detection part: the main body is a high-precision micro-gas chromatograph, the model is Agilent 990, which is used to accurately detect the composition and generation rate of the mixed gas after the reaction, and realize the fuel production performance of the test bench system At the same time, it is equipped with a computer to accept and analyze the data of the chromatograph and each flowmeter; the inlet of the chromatograph is an imperial 1/16 pipe, which can be connected with the 3mm stainless steel pipe behind the gas flowmeter with the corresponding connection method ; The chromatograph is equipped with corresponding standard gas in order to realize the calibration of the gas types detected by the chromatograph.

The invention discloses an evaluation method of a thermochemical fuel production reaction performance evaluation system based on a high-temperature reactor: the method includes the following steps:

Step 1: Power on the test bench, check that the status of each component is normal, check that the status of all switch instruments is correct, put the catalyst material used into the corundum crucible and put it into the pipeline of the high temperature reactor, after filling the catalyst, put it with the tube type Put the plug supporting the furnace into the corundum tube to prevent the temperature in the tube from being too high and melt the sealing ring at the same time to play the role of heat insulation, and then tighten the quick-connect flange behind the reactor pipe to seal the entire pipeline; turn on the circulating water pump , and pass into the cooling water.

Step 2: This step is the first step reaction of the high-temperature thermochemical fuel system reaction, that is, the catalyst material carries out a reduction reaction in a reducing atmosphere at a high temperature, and with ceria as a catalyst, the reduction reaction that occurs is described in the following equation:

This step releases oxygen, thereby generating oxygen vacancies for the second step reaction; turn on the vacuum pump to vacuumize the pipeline, then open the gas cylinder containing the carrier gas/protective gas, and use the pressure reducing valve to adjust the pressure at 0.1-0.2MPa , use the gas flow meter to adjust the gas flow, and purge each pipe section of the test bench system; turn on the high-temperature tube furnace, and adjust the corresponding program to control the temperature in sections to the reaction temperature of 1400 ° C, so that the catalyst can carry out the corresponding reduction reaction , the heating rate is 5-8°C/min to prevent the temperature of the heating furnace from changing too much and reduce the life of the instrument. At the same time, continue to feed the carrier gas/protection gas, the catalyst undergoes a reduction reaction in the high-temperature thermochemical fuel production, generates oxygen, and Timing controls the time for the first step of the oxygen release reaction;

Step 3: This step is the second-step oxidation reaction of high-temperature thermochemical fuel production. At a lower temperature, the oxygen-deficient catalyst material and the corresponding reactant (water or carbon dioxide) undergo an oxidation reaction to generate hydrogen or carbon monoxide. Due to the final reaction It is to generate gaseous fuel, so the reaction of this step is the key reaction in the process of high-temperature thermochemical fuel production. The second-step oxidation reaction of generating hydrogen with cerium dioxide as a catalyst and water as a raw material is described in the following equation:

After the first step of the reaction is completed, the program controls the cooling rate of the tube furnace within 10°C/min, lowers the temperature to 1000°C for the corresponding oxidation reaction, opens the cylinder containing the reaction gas, and controls it through the pressure reducing valve. The gas pressure is 0.1-0.2MPa, and the flow rate of the reaction gas is controlled by the gas flow meter. At the same time, with the introduction of the carrier gas/protection gas, the two gases enter the main pipeline after passing through the mixer, and then enter the reactor, where the first reaction occurs with the catalyst. Two-step fuel oxidation reaction, and control the reaction time; if the reactant is in the gas phase at room temperature, it can be controlled by a high-pressure gas cylinder connected to a gas flow meter, and if the reactant is water, it needs to be generated by the water vapor in the gas pretreatment part The unit controls the generation of water vapor to participate in the reaction.

Step 4: The carrier gas and reaction gas are continuously introduced, and the unreacted gas oxides and the hydrogen or carbon monoxide generated by the reaction, etc., are driven by the carrier gas/protective gas, leave the reactor and enter the condenser through a 3mm stainless steel tube. Among them, the high-temperature mixed gas is cooled by air and circulating water after passing through the pipeline and condenser to reduce the gas temperature and prevent damage to the instrument; if there are reactants that are liquid at normal temperature and pressure, such as water vapor, they will be condensed into liquid. , is collected through the gas-liquid separator and the gas is separated, and other mixed gases enter the dryer to be dried;

Step 5: The mixed gas after cooling and drying enters the gas chromatograph through the gas flow meter, and its components and production rates are detected and analyzed in detail. Fuel system performance and efficiency.

The type of carrier gas/protection gas can be selected according to the specific chemical reaction, including but not limited to nitrogen, argon, etc.; raw materials that are gaseous reactants at room temperature include but not limited to carbon dioxide, methane, and liquid at room temperature The reactant is generally water; the fuel gas generated is carbon monoxide or hydrogen; the temperature range of the high-temperature reactor is 700 degrees Celsius to 1600 degrees Celsius;

Embodiment one

Using water as a reactant, hydrogen is produced by using a thermochemical fuel production reaction performance evaluation system based on a high temperature reactor, and the corresponding performance evaluation is carried out. The specific implementation method is as follows:

(1) Pre-experiment preparation and feeding: power on the test bench, check that the status of each component is normal, check the status of all switches and valves in the pipeline to ensure that the experiment can be carried out smoothly, and power on the flowmeter and other control parts for accurate control; Fill 500mg of catalyst material into a corundum pot matching the size of the corundum tube in the reactor, and send the crucible into the high-temperature reactor 24 along the corundum tube until the crucible is in the constant temperature zone of the tube furnace to ensure the reaction of each step After the catalyst is placed, put the plug matching the tube furnace into the corundum tube, and tighten the fast flange behind the reactor; pour high-purity water into the syringe of the syringe pump in the evaporator 8 to generate water The steam provides the raw material; the circulating water pump of the condenser 10 is opened, and cooling water is introduced.

(2) Purging heating and reduction reaction: turn on the vacuum pump 31 to vacuumize the pipeline, then turn on the gas cylinder 29 filled with high-purity nitrogen, adjust the pressure reducing valve to make the outlet pressure 0.2MPa, and use a computer to control the gas flow meter 20 Adjust the flow rate of nitrogen to 100ml/min, purge the pipeline and various components for 30 minutes, and continue to feed nitrogen without changing the flow rate after the purge is completed; turn on the high-temperature tube furnace, and control the heating rate by programming the temperature in sections, first at 5°C The temperature was raised to 300°C at a heating rate of /min, and then to 1400°C at a heating rate of 8°C/min. During this process, the reduction reaction in the high-temperature thermochemical fuel production occurred to generate oxygen, and kept at 1400°C for 1 hour.

(3) Cooling and oxidation reaction: Control the tube furnace through the program to cool down to 1000°C at a cooling rate of 10°C/min to reach the temperature of the second oxidation reaction, and adjust the pipeline valve to allow nitrogen to flow into the steam generator to carry water vapor into the main pipeline; turn on the water vapor generator and syringe pump in the evaporator 8, adjust the perfusion flow rate of the syringe pump to 32 μl/min, and adjust the outlet temperature of the water vapor generator and the temperature of the heating belt to 120°C. Nitrogen carries water vapor into the main pipeline and enters the tube furnace, where it reacts with the catalyst to generate hydrogen, and keeps the reaction at 1000°C for 1 hour to complete the oxidation reaction.

(4) Cooling and drying: The high-temperature mixed gas after reaction is cooled by circulating water in the cooler 10, where the water vapor is condensed into liquid water and left in the gas-liquid separator 26, which can be opened by opening the valve below the gas-liquid separator Clear; and remaining gas such as hydrogen enters in the desiccator 27 by one-way valve, removes unnecessary water vapour.

(5) Data collection and component analysis: After the reacted mixed gas is cooled and dried, the flow rate is monitored in real time by the gas flow meter 17, and then enters the gas chromatograph 5 for component analysis, and the data is collected and processed by the computer to obtain oxygen and hydrogen The generation rate and amount of generation, to evaluate the reaction performance of high-temperature thermochemical cracking of carbon dioxide to fuel.

As shown in Figure 2, it is the data of the amount of hydrogen produced over time during a high-temperature thermochemical cracking of water to produce hydrogen. Collect data after the reaction. As shown in Figure 2, after the reaction system is fed with water vapor, hydrogen is generated, and it reaches a stable value of about 235 μmol/g after about 40 minutes. Then the production rate is stable, and no by-products are detected, and the hydrogen purity is relatively high.

To sum up, this system and method can generate a relatively large amount of stable fuel production data in a chemical reaction, the time for the system to reach stability is short, and compared with other thermochemical hydrogen production systems, the purity of hydrogen produced is higher, without By-product generation, hydrogen can be stably produced by continuously carrying out the corresponding chemical cycle.

Embodiment two

Using carbon dioxide as a reactant, carbon monoxide is produced by using a thermochemical fuel production reaction performance evaluation system based on a high temperature reactor, and the corresponding performance evaluation is carried out. The specific implementation method is as follows:

(1) Pre-experiment preparation and feeding: power on the test bench, check that the status of each component is normal, check the status of all switches and valves in the pipeline to ensure that the experiment can be carried out smoothly, and power on the flowmeter and other control parts for accurate control; Fill 500 mg of catalyst material into a corundum pot matching the size of the corundum tube in the reactor, and send the crucible into the high-temperature reactor 24 along the corundum tube until the crucible is in the constant temperature zone of the tube furnace to ensure that all steps are carried out. Reaction temperature, after the catalyst is placed, put the plug matching the tube furnace into the corundum tube, tighten the fast flange behind the reactor; turn on the circulating water pump of the condenser 10, and feed cooling water.

(2) Purge heating and reduction reaction: prepare for the first reduction reaction, turn on the vacuum pump 31 to vacuumize the pipeline, then open the gas cylinder 29 filled with high-purity nitrogen, and adjust the pressure reducing valve so that the outlet pressure is 0.2MPa , use a computer to control the gas flow meter 20 to adjust the flow rate of nitrogen to 100ml/min, purge the pipeline and various components for 30 minutes, and continue to feed nitrogen without changing the flow rate after the purge is completed; open the high-temperature tube furnace, and increase the temperature in sections through the program Control the heating rate, first raise the temperature to 300°C at a heating rate of 5°C/min, and then raise the temperature to 1400°C at a heating rate of 8°C/min. During this process, the catalyst undergoes a reduction reaction in high-temperature thermochemical fuel production to generate oxygen. And keep it at 1400°C for 1h.

(3) Cooling and oxidation reaction: Control the tube furnace through the program to cool down to 1000°C at a cooling rate of 10°C/min to reach the temperature of the second oxidation reaction, and then open the gas cylinder 28 filled with carbon dioxide to adjust the decompression The valve makes the outlet pressure 0.2MPa, and the gas flow meter 18 is controlled to adjust the gas flow rate of carbon dioxide to 100 ml/min. The carbon dioxide and nitrogen are uniformly mixed in the mixer 12, and the nitrogen is used as a carrier gas to carry carbon dioxide into the tube furnace, where it reacts with the catalyst. The oxidation reaction generates carbon monoxide, and the reaction is maintained at 1000°C for 1 hour to complete the oxidation reaction.

(4) Cooling: Incompletely reacted carbon dioxide and high-temperature mixed gases such as carbon monoxide are cooled by circulating water in the cooler 10 and then dried in the drier 27 .

(5) Data collection and component analysis: the dried mixed gas is monitored by the gas flow meter 17 in real time, and enters the gas chromatograph 5 for component analysis, and the data is collected and processed by the computer to obtain the generation rate and Yield to evaluate the reactivity of high-temperature thermochemical cracking of carbon dioxide to fuel.

The final experimental data are shown in Figure 3. The general trend is similar to the generation of hydrogen. Since carbon dioxide is gaseous at room temperature, the system reaches stability and the reaction speed is faster, and the time to start generating carbon monoxide is shorter, and the amount of carbon monoxide generated is relatively stable and higher than that of hydrogen. The output is high, the stable value is about 265 μmol/g, the data error is small, and the carbon monoxide purity is high, no side reactions occur, and the performance is better than other experimental evaluation systems for thermochemical fuel production.

A high-temperature reactor-based thermochemical fuel reaction performance evaluation system and method involved in the present invention are not limited to the structures and steps described in the above embodiments. The above is only a basic description under the inventive concept, and any equivalent transformation or combined use made according to the technical solution of the present invention shall belong to the protection scope of the present invention.

Claims (1)

1. A method for evaluating a reaction performance evaluation system of thermochemical fuel based on a high-temperature reactor comprises the reaction performance evaluation system of thermochemical fuel based on the high-temperature reactor, wherein the system comprises a gas pretreatment part, the high-temperature reactor part, a flow control and pipeline part, a condensation part, a drying part and a gas component detection part; the gas pretreatment part: comprises a gas direct input part and a liquid phase conversion gas phase part; the gas direct input part provides carrier gas/protective gas or reaction gas by a gas cylinder, and the gas is fully mixed in a mixer and then enters a main pipeline; the liquid phase conversion gas phase part is carried by carrier gas to enter a main pipeline; the high temperature reactor section: the output end of the high-temperature reactor is connected with a vacuum pump and a condenser; the flow control and pipeline part: arranging one-way switches at each control node of the pipeline; different pipe sections are provided with corresponding one-way valves, vacuum meters, gas flow meters and thermocouples; the condensing part: the condenser is connected with the high-temperature reactor through a stainless steel pipe, and a check valve is arranged on the stainless steel pipe to prevent high-temperature gas from flowing back to enter the reactor; a vacuum meter is arranged behind the one-way valve and used for monitoring the pressure of the mixed gas after reaction in real time; the lower part of the condenser is connected with a gas-liquid separator through a stainless steel pipeline for collecting liquid substances condensed into liquid substances; the drying part: introducing the condensed gas into a dryer, wherein one to two drying columns are arranged inside the dryer, and a one-way valve is arranged in a pipeline in front of the dryer to prevent the mixed gas from flowing backwards; the back of the dryer is connected with a one-way switch and connected with a gas flowmeter; the gas component detection section: the dried mixed gas is connected with a chromatograph through a gas flow meter, and a computer is equipped to receive and process data of the chromatograph and each flow meter; the high-temperature reactor main body is an electric heating or infrared heating high-temperature tube furnace, wherein a corundum tube bearing high temperature is designed inside the high-temperature tube furnace; the flow control and pipeline part comprises a stainless steel pipe, a polytetrafluoroethylene pipe and a connecting joint between pipelines, wherein the types of the pipelines comprise but are not limited to high-temperature-resistant and corrosion-resistant stainless steel pipes, and the tightness is ensured in a stainless steel fastening mode; the condenser in the condensing part is connected with the high-temperature reactor through a 3mm stainless steel pipe, and the steel pipe is subjected to protection and heat insulation treatment; the chromatograph detects the type and the rate of the generated mixed gas and is used for overall evaluation of the reaction performance of the thermochemical fuel of the evaluation system;

it is characterized in that: the method comprises the following steps:

step 1: putting the used catalyst material into a corundum crucible, putting the corundum crucible into a pipeline of a high-temperature reactor, filling the corundum crucible with the catalyst, putting a plug, and screwing a quick-connection flange behind the pipeline of the reactor; opening a circulating water pump, and introducing cooling water;

step 2, opening a vacuum pump to vacuumize the pipeline, then opening a gas cylinder with carrier gas/protective gas, adjusting pressure by using a pressure reducing valve, adjusting gas flow by using a gas flowmeter, and purging each pipe section part of the experiment table system; opening the high-temperature tube furnace, adjusting the corresponding program to control the heating rate to a proper temperature, simultaneously continuing to introduce carrier gas/protective gas, performing a first-step reduction reaction in the high-temperature thermochemical fuel preparation to generate oxygen, and timing to control the running time of the reduction reaction;

and step 3: controlling the tubular furnace to reduce the temperature, opening a gas cylinder storing reaction gas, controlling the pressure by a pressure reducing valve, controlling the flow of the reaction gas by a gas flowmeter, simultaneously matching with the introduction of carrier gas/protective gas, and enabling the two gases to enter a main pipeline after passing through a mixer and then enter a reactor to perform a second-step oxidation reaction with the material; when gas enters the reactor, a second-step oxidation reaction is carried out on the gas and the material, wherein if the reactant is in a gas phase at normal temperature, the reactant can enter the reactor under the control of a high-pressure gas cylinder connected with a gas flow meter, and if the reactant is water, the reactant needs to be controlled to generate steam through a steam generation unit of a gas pretreatment part so as to participate in the reaction;

and 4, step 4: the gas oxide which is not completely reacted and the hydrogen or carbon monoxide generated by the reaction are pushed by the carrier gas/protective gas to leave the reactor and then enter a condenser; when the mixed gas is cooled, the reactant which is liquid at normal temperature is condensed into liquid, the liquid is separated and collected in a gas-liquid separator, and other mixed gas enters a dryer to be dried;

and 5: the dried mixed gas enters a gas chromatograph through a gas flowmeter, each component of the mixed gas is subjected to detailed detection and analysis, and the obtained data is processed by a computer to evaluate the performance and efficiency of the whole fuel system prepared by high-temperature thermochemical cracking of oxides;

the temperature range of the high-temperature reactor is 700-1600 ℃; the method comprises the steps of taking water as a reactant, preparing hydrogen by using a thermochemical fuel preparation reaction performance evaluation system based on a high-temperature reactor, and carrying out corresponding performance evaluation, or taking carbon dioxide as a reactant, preparing carbon monoxide by using the thermochemical fuel preparation reaction performance evaluation system based on the high-temperature reactor, and carrying out corresponding performance evaluation.

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