Method for measuring mixing ratio of biomass to coal in combustion

Abstract

The invention relates to the technical field of coal and biomass coupling combustion, in particular to a method for measuring the mixing proportion of biomass and coal in combustion. In a conventional method, carbon dioxide in smoke generated after biomass and coal are combusted is collected, gas obtained after smoke is filtered is directly introduced into a sodium hydroxide aqueous solution reagent bottle to be collected, it cannot be guaranteed that the carbon dioxide in the smoke is completely absorbed, and the accuracy of biomass mixing proportion testing is affected. According to the method, the carbon dioxide absorption device is self-made under laboratory conditions, carbon dioxide in flue gas is more fully absorbed and fully converted into strontium carbonate by using an air bag collection method, a graphite sample is obtained by using a graphite sample preparation system, and the method remarkably improves the precision of a biomass mixing ratio test value.

Description

Technical Field

[0001] The invention relates to the technical field of coupled combustion of coal and biomass, and in particular to a method for determining a combustion blending ratio of biomass and coal. Background Art

[0002] The coupled combustion of biomass and coal can improve the utilization rate of biomass resources, alleviate the environmental pollution caused by coal burning, and achieve energy conservation and emission reduction effects.

[0003] The co-firing technology of biomass and coal in power plants requires high-precision measurement of the biomass blending ratio to obtain the optimal blending ratio, which not only burns and utilizes the biomass, but also achieves higher combustion efficiency and more combustion heat. The co-firing technology of biomass and coal is widely used in power plants, which can effectively adjust the energy use structure and meet the "dual carbon" development concept.

[0004] At present, in order to determine the blending ratio of biomass in coal, accelerator mass spectrometry (AMS) is generally used. 14 C detection method is used for determination. This process requires that the carbon dioxide in the flue gas obtained by the complete combustion of biomass and coal be fully absorbed and completely converted into sodium carbonate, and then further converted into solid strontium carbonate powder, and then subjected to hydrochloric acid reaction and reduction reaction to finally obtain a graphite sample. In the process of converting carbon dioxide into a graphite sample, it is necessary to fully absorb the carbon dioxide in the flue gas generated by the complete combustion of biomass and coal, and prevent the incorporation of carbon dioxide in the air. Otherwise, it is impossible to more accurately calculate the mixing ratio of biomass and coal. Conventional method (the device for collecting carbon dioxide in flue gas used is as attached to the instruction manual) Figure 4 As shown in the figure, the flue gas generated by the combustion of biomass and coal is generally filtered, and the filtered gas is passed into a sodium hydroxide aqueous solution reagent bottle for collection, and then the generated sodium carbonate solution is converted into strontium carbonate. This process cannot ensure that the carbon dioxide in the flue gas is completely absorbed, and the sodium hydroxide solution is easily mixed with air during the process of absorbing carbon dioxide, which affects the accuracy of the mixing ratio test. Summary of the invention

[0005] The problem in the prior art is that in the conventional method, the carbon dioxide in the flue gas generated after the combustion of biomass and coal is collected by directly passing the gas after the flue gas is filtered into a sodium hydroxide aqueous solution reagent bottle for collection, which cannot ensure that the carbon dioxide in the flue gas is completely absorbed, affecting the accuracy of the biomass blending ratio test. In view of the above problems, the present invention provides a carbon dioxide absorption device, which includes a first absorber, a second absorber, and a third absorber;

[0006] The first absorber is located inside the second absorber, and a closed annular cavity 1 is formed between the inner wall of the second absorber and the outer wall of the first absorber; the second absorber is located inside the third absorber, and a closed annular cavity 2 is formed between the second absorber and the third absorber; the first absorber, the second absorber and the third absorber are all closed containers;

[0007] A rubber stopper is provided on the top of the first absorber, and a first connecting tube and a second connecting tube are passed through the surface of the rubber stopper. One end of the first connecting tube extends to a position close to the bottom of the first absorber, and the other end of the first connecting tube is connected to a micro vacuum pump through a hose. The micro vacuum pump is connected to the first air bag through a hose. One end of the second connecting tube is close to the top of the first absorber, and the other end of the second connecting tube extends to a position close to the bottom of the second absorber. The second connecting tube is sealed and connected to the top of the second absorber through the rubber stopper.

[0008] A rubber stopper is provided on the top of the second absorber, a third connecting tube is passed through the surface of the rubber stopper, one end of the third connecting tube is close to the top of the second absorber, the other end of the third connecting tube extends to a position close to the bottom of the third absorber, and the third connecting tube is tightly connected to the top of the third absorber through the rubber stopper;

[0009] A rubber plug is provided on the upper part of the third absorber, a fourth connecting pipe is passed through the surface of the rubber plug, one end of the fourth connecting pipe is close to the top of the third absorber, and the other end of the fourth connecting pipe is connected to the second air bag through a hose;

[0010] The bottoms of the first absorber, the second absorber and the third absorber are all filled with sodium hydroxide aqueous solution. The sodium hydroxide aqueous solution in the first absorber is above the opening at the end of the first connecting pipe, the sodium hydroxide aqueous solution in the second absorber is above the opening at the end of the second connecting pipe, and the sodium hydroxide aqueous solution in the third absorber is above the opening at the end of the third connecting pipe.

[0011] Preferably, the hose is made of silicone.

[0012] Preferably, the first absorber, the second absorber and the third absorber are made of glass.

[0013] Preferably, the first connecting tube, the second connecting tube, the third connecting tube and the fourth connecting tube are made of glass.

[0014] A method for determining the mixing ratio of biomass and coal during combustion uses the above-mentioned carbon dioxide absorption device to absorb carbon dioxide in the flue gas generated by the combustion of biomass and coal and convert it into sodium carbonate.

[0015] A method for determining the mixing ratio of biomass and coal combustion comprises the following steps:

[0016] (1) placing a sample to be tested consisting of biomass and coal in a dual-temperature vertical furnace for full combustion, and using a first air bag to collect flue gas after full combustion;

[0017] (2) continuously pumping high-purity nitrogen or inert gas into the carbon dioxide absorption device through a micro vacuum pump to evacuate the air in the first absorber, the second absorber, and the third absorber in the carbon dioxide absorption device;

[0018] (3) Afterwards, the flue gas in the first air bag is continuously pumped into the first connecting pipe through a micro vacuum pump and passed into the sodium hydroxide aqueous solution at the bottom of the first absorber, the carbon dioxide not absorbed by the sodium hydroxide aqueous solution is passed from the second connecting pipe at the top of the first absorber into the sodium hydroxide aqueous solution at the bottom of the second absorber, the carbon dioxide not absorbed by the sodium hydroxide aqueous solution is passed from the third connecting pipe at the top of the second absorber into the sodium hydroxide aqueous solution at the bottom of the third absorber, and the carbon dioxide not absorbed by the sodium hydroxide aqueous solution is passed from the fourth connecting pipe at the top of the third absorber into the second air bag;

[0019] (4) After the gas in the first air bag is completely emptied, the position of the second air bag is swapped with the first air bag, so that the gas in the second air bag is continuously pumped into the first connecting pipe by the micro vacuum pump and passed into the sodium hydroxide aqueous solution at the bottom of the first absorber. By repeatedly swapping the first air bag and the second air bag, the carbon dioxide in the flue gas collected in step (1) is fully absorbed by the sodium hydroxide aqueous solution in the carbon dioxide device and converted into sodium carbonate;

[0020] (5) After step (4), the three solutions in the first absorber, the second absorber and the third absorber are mixed to obtain a collected solution, and the pH of the collected solution is adjusted to 10-10.2 with an aqueous ammonium chloride solution, and then an excess of a saturated strontium chloride aqueous solution is added to the collected solution, and the mixture is stirred to react to obtain a solid precipitate, and after solid-liquid separation and drying, a solid strontium carbonate powder is obtained;

[0021] (6) Strontium carbonate solid powder is added to excess hydrochloric acid to react and generate carbon dioxide. The obtained carbon dioxide is completely reduced to carbon monoxide. The carbon monoxide is completely catalytically reduced to graphite under high temperature environment. The obtained graphite is analyzed by accelerator mass spectrometry. 14 The C content was determined to obtain the blending ratio of the biomass.

[0022] The present invention has the following beneficial effects:

[0023] (1) The present invention uses laboratory conditions to make a self-made carbon dioxide absorption device, and uses an air bag collection method to achieve more complete absorption of carbon dioxide in flue gas and fully convert it into strontium carbonate. Finally, a graphite sample preparation system is used to obtain a graphite sample. This method significantly improves the accuracy of the biomass blending ratio test value;

[0024] (2) The present invention uses conventional laboratory equipment to simulate the working conditions of the mixed combustion of biomass and coal in a power plant, and more efficiently converts the collected flue gas into SrCO3 samples for the preparation of graphite samples, which significantly reduces the impact of CO2 in the air and promotes the AMS-based 14 The C detection method is more widely used in the determination of the biomass blending ratio in coal, providing a reference basis for the comprehensive evaluation of coal-biomass coupled power generation systems. It is of great significance for the more rational use of biomass and coal energy and the promotion of "dual carbon" and sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 : Schematic diagram of the structure of the device for collecting carbon dioxide in flue gas generated by the complete combustion of pine wood and bituminous coal in Example 1.

[0026] Figure 2 : Schematic diagram of the principle structure of absorbing carbon dioxide gas using a carbon dioxide absorption device in Example 1.

[0027] Figure 3 : Schematic diagram of the structure of the graphite sample preparation system in Example 1.

[0028] Figure 4 : Schematic diagram of the device structure for collecting carbon dioxide in flue gas generated by the complete combustion of biomass and coal using a conventional method and converting it into sodium carbonate.

[0029] Figure 5 : Figure 2 Schematic diagram of the cross-sectional structure of the solid structure of part A in the middle.

[0030] In the figure: 1. first connecting pipe, 2. second connecting pipe, 3. third connecting pipe, 4. fourth connecting pipe, 5. first absorber, 6. second absorber, 7. third absorber, 8. rubber plug. DETAILED DESCRIPTION

[0031] The present invention is described in detail below with reference to the examples. However, it should be understood that the following examples are only illustrative of the embodiments of the present invention, and are not intended to limit the scope of the present invention.

[0032] Example 1

[0033] (1) Pine wood and bituminous coal are crushed and sieved to particle sizes of 60 mesh and 150 mesh, respectively, and the sieved raw materials are placed in a 105°C oven for drying for 12 hours. 0.3005g of pine wood and 1.7005g of bituminous coal are weighed at a biomass blending ratio of 15%, mixed evenly, and placed in a hanging basket sample tube. The hanging basket sample tube is placed in a quartz reaction tube of a double-temperature zone vertical furnace, and a temperature-raising ventilation program is used to perform a full combustion reaction. The generated flue gas is passed through a microfilter to remove solid particles. The filtered flue gas is passed through a condensation device to remove moisture from the gas, and then the gas is collected by a first air bag. The schematic diagram of collecting carbon dioxide in the flue gas during this reaction process is shown in the attached manual. Figure 1 As shown;

[0034] (2) High-purity nitrogen is continuously pumped into the carbon dioxide absorption device through a micro vacuum pump to evacuate the air in the first absorber, the second absorber, and the third absorber in the carbon dioxide absorption device. Then, the second air bag is connected to a hose connected to the fourth connecting pipe, and the hose in the first air bag connected to the micro vacuum pump is connected. Before the first air bag and the second air bag are connected to the carbon dioxide absorption device, the hose connection is sealed by a sealing clamp to ensure that no air is mixed during the connection process;

[0035] (3) The carbon dioxide gas in the first air bag is continuously pumped into the first connecting pipe through a micro vacuum pump and passed into the 1M sodium hydroxide aqueous solution at the bottom of the first absorber. The carbon dioxide that is not absorbed by the sodium hydroxide aqueous solution is passed from the second connecting pipe at the top of the first absorber into the 1M sodium hydroxide aqueous solution at the bottom of the second absorber. The carbon dioxide that is not absorbed by the sodium hydroxide aqueous solution is passed from the third connecting pipe at the top of the second absorber into the 1M sodium hydroxide aqueous solution at the bottom of the third absorber. The carbon dioxide that is not absorbed by the sodium hydroxide aqueous solution is passed from the fourth connecting pipe at the top of the third absorber into the second air bag. The structural schematic diagram of the carbon dioxide absorption device used in this process is shown in the attached manual. Figure 2 As shown;

[0036] The liquid level of the sodium hydroxide aqueous solution in the first absorber is 14 cm and the volume is 700 mL. The liquid level of the sodium hydroxide aqueous solution in the second absorber is 5 cm and the volume is 200 mL. The liquid level of the sodium hydroxide aqueous solution in the third absorber is 2.4 cm and the volume is 100 mL.

[0037] (4) After the gas in the first air bag is completely emptied, the position of the second air bag is swapped with the first air bag, so that the gas in the second air bag is continuously pumped into the first connecting pipe by the micro vacuum pump and passed into the sodium hydroxide aqueous solution at the bottom of the first absorber. By repeatedly swapping the first air bag and the second air bag, the carbon dioxide in the flue gas collected in step (3) is fully absorbed by the sodium hydroxide aqueous solution in the carbon dioxide device and converted into sodium carbonate;

[0038] (5) After step (4), the three solutions in the first absorber, the second absorber and the third absorber were mixed to obtain a collected solution, and the pH of the collected solution was adjusted to 10.08 using a 2 mol / L ammonium chloride aqueous solution. Then, an excess of a saturated strontium chloride aqueous solution was added to the collected solution, and the mixture was stirred to react to obtain a solid precipitate. After suction filtration and drying in an oven at 105° C. for 12 h, 10.175 g of strontium carbonate solid powder was obtained;

[0039] (6) Strontium carbonate solid powder is added to the graphite sample preparation system. The strontium carbonate solid powder reacts with excess hydrochloric acid to generate carbon dioxide. The obtained carbon dioxide is completely reduced to carbon monoxide. The carbon monoxide is finally completely catalytically reduced under high temperature environment to obtain 2.20 mg of graphite. The structural diagram of the graphite sample preparation system is shown in the attached manual. Figure 3 As shown;

[0040] (7) The 14C content of the obtained graphite was measured by accelerator mass spectrometry to obtain the blending ratio of biomass. The blending ratio of biomass was measured to be 15.3399%, the combustion residue was 0.4960g, the difference was 1.45% compared with the theoretical ash content of 0.4889g, the CO2 absorption rate was 95.30%, and the relative error of the obtained biomass blending ratio was 2.13%.

[0041] Example 2

[0042] (1) The bamboo chips and bituminous coal were crushed and sieved to particle sizes of 60 mesh and 150 mesh, respectively, and the sieved raw materials were placed in an oven at 105° C. and dried for 12 hours. 0.2011 g of bamboo chips and 1.8012 g of bituminous coal were weighed at a biomass blending ratio of 10%, mixed evenly, and placed in a hanging basket sample tube. The hanging basket sample tube was placed in a quartz reaction tube of a dual-temperature zone vertical furnace, and a temperature-raising ventilation program was performed to fully burn the reaction. The generated flue gas was passed through a microfilter to remove solid particles. The filtered flue gas was passed through a condenser to remove moisture from the gas, and then the gas was collected by a first air bag;

[0043] (2) High-purity nitrogen is continuously pumped into the carbon dioxide absorption device through a micro vacuum pump to evacuate the air in the first absorber, the second absorber, and the third absorber in the carbon dioxide absorption device. Then, the second air bag is connected to a hose connected to the fourth connecting pipe, and the hose in the first air bag connected to the micro vacuum pump is connected. Before the first air bag and the second air bag are connected to the carbon dioxide absorption device, the hose connection is sealed by a sealing clamp to ensure that no air is mixed during the connection process;

[0044] (3) The carbon dioxide gas in the first air bag is continuously pumped into the first connecting pipe through a micro vacuum pump and passed into the 1M sodium hydroxide aqueous solution at the bottom of the first absorber. The carbon dioxide that is not absorbed by the sodium hydroxide aqueous solution is passed from the second connecting pipe at the top of the first absorber into the 1M sodium hydroxide aqueous solution at the bottom of the second absorber. The carbon dioxide that is not absorbed by the sodium hydroxide aqueous solution is passed from the third connecting pipe at the top of the second absorber into the 1M sodium hydroxide aqueous solution at the bottom of the third absorber. The carbon dioxide that is not absorbed by the sodium hydroxide aqueous solution is passed from the fourth connecting pipe at the top of the third absorber into the second air bag.

[0045] The liquid level of the sodium hydroxide aqueous solution in the first absorber is 14 cm and the volume is 700 mL. The liquid level of the sodium hydroxide aqueous solution in the second absorber is 5 cm and the volume is 200 mL. The liquid level of the sodium hydroxide aqueous solution in the third absorber is 2.4 cm and the volume is 100 mL.

[0046] (4) After the gas in the first air bag is completely emptied, the position of the second air bag is swapped with the first air bag, so that the gas in the second air bag is continuously pumped into the first connecting pipe by the micro vacuum pump and passed into the sodium hydroxide aqueous solution at the bottom of the first absorber. By repeatedly swapping the first air bag and the second air bag, the carbon dioxide in the flue gas collected in step (3) is fully absorbed by the sodium hydroxide aqueous solution in the carbon dioxide device and converted into sodium carbonate;

[0047] (5) After step (4), the three solutions in the first absorber, the second absorber and the third absorber were mixed to obtain a collected solution, and the pH of the collected solution was adjusted to 10.11 using a 2 mol / L ammonium chloride aqueous solution. Then, an excess of a saturated strontium chloride aqueous solution was added to the collected solution, and the mixture was stirred to react to obtain a solid precipitate. After suction filtration and drying in an oven at 105° C. for 12 h, 10.346 g of strontium carbonate solid powder was obtained;

[0048] (6) Strontium carbonate solid powder is added to a graphite sample preparation system, and the strontium carbonate solid powder reacts with excess hydrochloric acid to generate carbon dioxide, and the obtained carbon dioxide is completely reduced to carbon monoxide, and the carbon monoxide is finally completely catalytically reduced under a high temperature environment to obtain 2.40 mg of graphite;

[0049] (7) The 14C content of the obtained graphite was measured by accelerator mass spectrometry to obtain the blending ratio of biomass. The blending ratio of biomass was measured to be 10.3884%, the combustion residue was 0.5271 g, the difference was 2.11% compared with the theoretical ash content of 0.5162 g, the CO2 absorption rate was 98.90%, and the relative error of the obtained biomass blending ratio was 3.47%.

[0050] Example 3

[0051] (1) Pine wood and lignite are crushed and sieved to particle sizes of 60 mesh and 150 mesh, respectively, and the sieved raw materials are placed in an oven at 105° C. and dried for 12 hours. 0.1003 g of pine wood and 1.9012 g of lignite are weighed at a biomass blending ratio of 5%, mixed evenly, and placed in a hanging basket sample tube. The hanging basket sample tube is placed in a quartz reaction tube of a dual-temperature zone vertical furnace, and a temperature-raising ventilation program is performed to fully burn the reaction. The generated flue gas is passed through a microfilter to remove solid particles. The filtered flue gas is passed through a condenser to remove moisture from the gas, and then the gas is collected by a first air bag;

[0052] (2) High-purity nitrogen is continuously pumped into the carbon dioxide absorption device through a micro vacuum pump to evacuate the air in the first absorber, the second absorber, and the third absorber in the carbon dioxide absorption device. Then, the second air bag is connected to a hose connected to the fourth connecting pipe, and the hose in the first air bag connected to the micro vacuum pump is connected. Before the first air bag and the second air bag are connected to the carbon dioxide absorption device, the hose connection is sealed by a sealing clamp to ensure that no air is mixed during the connection process;

[0053] (3) The carbon dioxide gas in the first air bag is continuously pumped into the first connecting pipe through a micro vacuum pump and passed into the 1M sodium hydroxide aqueous solution at the bottom of the first absorber. The carbon dioxide that is not absorbed by the sodium hydroxide aqueous solution is passed from the second connecting pipe at the top of the first absorber into the 1M sodium hydroxide aqueous solution at the bottom of the second absorber. The carbon dioxide that is not absorbed by the sodium hydroxide aqueous solution is passed from the third connecting pipe at the top of the second absorber into the 1M sodium hydroxide aqueous solution at the bottom of the third absorber. The carbon dioxide that is not absorbed by the sodium hydroxide aqueous solution is passed from the fourth connecting pipe at the top of the third absorber into the second air bag.

[0054] The liquid level of the sodium hydroxide aqueous solution in the first absorber is 14 cm and the volume is 700 mL. The liquid level of the sodium hydroxide aqueous solution in the second absorber is 5 cm and the volume is 200 mL. The liquid level of the sodium hydroxide aqueous solution in the third absorber is 2.4 cm and the volume is 100 mL.

[0055] (4) After the gas in the first air bag is completely emptied, the position of the second air bag is swapped with the first air bag, so that the gas in the second air bag is continuously pumped into the first connecting pipe by the micro vacuum pump and passed into the sodium hydroxide aqueous solution at the bottom of the first absorber. By repeatedly swapping the first air bag and the second air bag, the carbon dioxide in the flue gas collected in step (3) is fully absorbed by the sodium hydroxide aqueous solution in the carbon dioxide device and converted into sodium carbonate;

[0056] (5) After step (4), the three solutions in the first absorber, the second absorber and the third absorber were mixed to obtain a collected solution, and the pH of the collected solution was adjusted to 10.06 using a 2 mol / L ammonium chloride aqueous solution. Then, an excess of a saturated strontium chloride aqueous solution was added to the collected solution, and the mixture was stirred to react to obtain a solid precipitate. After suction filtration and drying in an oven at 105° C. for 12 h, 13.487 g of strontium carbonate solid powder was obtained;

[0057] (6) Strontium carbonate solid powder is added to the graphite sample preparation system, and the strontium carbonate solid powder reacts with excess hydrochloric acid to generate carbon dioxide, and the obtained carbon dioxide is completely reduced to carbon monoxide by zinc powder and hydrogen. The carbon monoxide is finally completely reduced and carbonized under high temperature environment to obtain 2.40 mg of graphite;

[0058] (7) The obtained graphite was subjected to accelerator mass spectrometry. 14 The C content was determined to obtain the blending ratio of biomass. The blending ratio of biomass was 5.2544%, the combustion residue was 0.1661g, the difference was 0.61% compared with the theoretical ash content of 0.1651g, the CO2 absorption rate was 95.42%, and the relative error of the biomass blending ratio was 4.88%.

[0059] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A carbon dioxide absorption device, characterized in that: comprising a first absorber, a second absorber and a third absorber; The first absorber is located inside the second absorber, and a closed annular cavity 1 is formed between the inner wall of the second absorber and the outer wall of the first absorber; the second absorber is located inside the third absorber, and a closed annular cavity 2 is formed between the second absorber and the third absorber; the first absorber, the second absorber and the third absorber are all closed containers; A rubber stopper is provided on the top of the first absorber, and a first connecting tube and a second connecting tube are passed through the surface of the rubber stopper. One end of the first connecting tube extends to a position close to the bottom of the first absorber, and the other end of the first connecting tube is connected to a micro vacuum pump through a hose. The micro vacuum pump is connected to the first air bag through a hose. One end of the second connecting tube is close to the top of the first absorber, and the other end of the second connecting tube extends to a position close to the bottom of the second absorber. The second connecting tube is sealed and connected to the top of the second absorber through the rubber stopper. A rubber stopper is provided on the top of the second absorber, a third connecting tube is passed through the surface of the rubber stopper, one end of the third connecting tube is close to the top of the second absorber, the other end of the third connecting tube extends to a position close to the bottom of the third absorber, and the third connecting tube is tightly connected to the top of the third absorber through the rubber stopper; A rubber plug is provided on the upper part of the third absorber, a fourth connecting pipe is passed through the surface of the rubber plug, one end of the fourth connecting pipe is close to the top of the third absorber, and the other end of the fourth connecting pipe is connected to the second air bag through a hose; The bottoms of the first absorber, the second absorber and the third absorber are all filled with sodium hydroxide aqueous solution. The sodium hydroxide aqueous solution in the first absorber is above the opening at the end of the first connecting pipe, the sodium hydroxide aqueous solution in the second absorber is above the opening at the end of the second connecting pipe, and the sodium hydroxide aqueous solution in the third absorber is above the opening at the end of the third connecting pipe.

2. A carbon dioxide absorption device according to claim 1, characterized in that: The hose is made of silicone.

3. A carbon dioxide absorption device according to claim 1, characterized in that: The first absorber, the second absorber and the third absorber are made of glass.

4. A carbon dioxide absorption device according to claim 1, characterized in that: The first connecting tube, the second connecting tube, the third connecting tube and the fourth connecting tube are made of glass.

5. A method for determining the mixing ratio of biomass and coal combustion, characterized in that: The carbon dioxide absorption device according to any one of claims 1 to 4 is used to absorb carbon dioxide in flue gas generated by the combustion of biomass and coal and convert it into sodium carbonate.

6. The method for determining the mixing ratio of biomass and coal combustion according to claim 5, characterized in that: The following steps are involved: (1) placing a sample to be tested consisting of biomass and coal in a dual-temperature vertical furnace for full combustion, and using a first air bag to collect flue gas after full combustion; (2) continuously pumping high-purity nitrogen or inert gas into the carbon dioxide absorption device through a micro vacuum pump to evacuate the air in the first absorber, the second absorber, and the third absorber in the carbon dioxide absorption device; (3) Afterwards, the flue gas in the first air bag is continuously pumped into the first connecting pipe through a micro vacuum pump and passed into the sodium hydroxide aqueous solution at the bottom of the first absorber, the carbon dioxide not absorbed by the sodium hydroxide aqueous solution is passed from the second connecting pipe at the top of the first absorber into the sodium hydroxide aqueous solution at the bottom of the second absorber, the carbon dioxide not absorbed by the sodium hydroxide aqueous solution is passed from the third connecting pipe at the top of the second absorber into the sodium hydroxide aqueous solution at the bottom of the third absorber, and the carbon dioxide not absorbed by the sodium hydroxide aqueous solution is passed from the fourth connecting pipe at the top of the third absorber into the second air bag; (4) After the gas in the first air bag is completely emptied, the position of the second air bag is swapped with the first air bag, so that the gas in the second air bag is continuously pumped into the first connecting pipe by the micro vacuum pump and passed into the sodium hydroxide aqueous solution at the bottom of the first absorber. By repeatedly swapping the first air bag and the second air bag, the carbon dioxide in the flue gas collected in step (1) is fully absorbed by the sodium hydroxide aqueous solution in the carbon dioxide device and converted into sodium carbonate; (5) After step (4), the three solutions in the first absorber, the second absorber and the third absorber are mixed to obtain a collected solution, and the pH of the collected solution is adjusted to 10-10.2 with an aqueous ammonium chloride solution, and then an excess of a saturated strontium chloride aqueous solution is added to the collected solution, and the mixture is stirred to react to obtain a solid precipitate, and after solid-liquid separation and drying, a solid strontium carbonate powder is obtained; (6) Strontium carbonate solid powder is added to excess hydrochloric acid to react and generate carbon dioxide. The obtained carbon dioxide is fully reduced to carbon monoxide. The carbon monoxide is completely catalytically reduced to graphite under high temperature environment. The obtained graphite is analyzed by accelerator mass spectrometry. 14 The C content was determined to obtain the blending ratio of the biomass.

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