Cement kiln O2 / H2O combustion carbon dioxide trapping system
By using O2/H2O combustion and carbon dioxide capture system in cement kilns, the problems of low decomposition rate and high decomposition temperature under the existing O2/CO2 combustion technology are solved, and efficient and economical carbon capture and energy consumption are achieved.
Patent Information
- Application Number
- CN202421488431.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-27
- Publication Date
- 2025-04-08
- Estimated Expiration
- 2034-06-27
AI Technical Summary
Under the existing O2/CO2 combustion carbon capture technology of cement kilns, the decomposition rate of raw materials is low and the decomposition temperature is high, resulting in increased energy consumption and operating safety risks, limiting the industrialization process of cement kilns carbon dioxide capture technology.
The O2/H2O combustion capture system is adopted to burn under O2/H2O atmosphere in the decomposition furnace and rotary kiln respectively. The carbon dioxide is captured through the circulating fan and the carbon dioxide capture module, avoiding the difficulty of decomposing raw materials under high concentrations of CO2.
While ensuring the decomposition rate and decomposition rate of calcium carbonate in raw materials, efficient and economical carbon capture is achieved, reducing energy consumption and improving operational safety.
Smart Images
Figure CN222733306U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of cement production, in particular to a system for capturing carbon dioxide by burning O2 / H2O in a cement kiln. Background Art
[0002] The greenhouse effect caused by CO2 emitted by human activities has become a severe ecological challenge facing mankind. With the rapid development of my country's economy, my country's CO2 emissions exceeded those of other countries in the world in 2006, and its per capita carbon emissions exceeded the world average in 2010. To this end, in 2020, my country declared at the 75th United Nations General Assembly that it would strive to peak carbon dioxide emissions before 2030 and strive to achieve carbon neutrality before 2060.
[0003] Analysis of my country’s carbon emission structure shows that the power, steel, cement and other industries are the main sources of emissions. In 2020, my country’s cement industry CO2 emissions reached 13.75×10 8 t, accounting for 13.5% of the country's total emissions. The cement industry has become the third largest source of carbon emissions after the power and steel industries. Reducing carbon emissions in the cement industry is of great significance to achieving the dual carbon strategic goals.
[0004] The CO2 emitted during cement production mainly comes from the decomposition of limestone and the combustion of fossil fuels, which accounts for 90-95% of the total carbon emissions from cement production. Currently, technicians have reduced carbon emissions from cement production to a certain extent through energy efficiency improvement, fuel or raw material substitution, and other means, which has promoted the low-carbon development of the cement industry. However, the above means are difficult to fundamentally solve the problem of carbon emissions.
[0005] Carbon capture, utilization and storage (CCUS) is considered to be the last mile to control greenhouse gas emissions and achieve carbon neutrality. CCUS technology captures and utilizes carbon dioxide generated during cement production, thereby significantly reducing carbon emissions in the cement industry. Cement kiln CCUS technology mainly includes combustion carbon capture technology (O2 / CO2 combustion) and post-combustion carbon capture technology. Post-combustion carbon capture technology uses the principle of chemical adsorption to capture CO2 in flue gas through adsorbents. It has the advantage of high process maturity, but it has the disadvantages of high energy consumption of adsorbent capture and easy deactivation of adsorbents. Combustion carbon capture uses oxygen obtained from air separation to replace air and burn with fuel in rotary kilns and decomposition furnaces to increase the concentration of carbon dioxide in flue gas. However, under O2 / CO2 combustion, raw materials decompose in a high concentration of carbon dioxide atmosphere. High concentrations of carbon dioxide cause the decomposition reaction of calcium carbonate to proceed in the reverse direction, which inhibits the decomposition of calcium carbonate and reduces the decomposition rate of calcium carbonate. O2 / CO2 combustion requires a higher decomposition reaction temperature, such as 1100°C, which greatly increases the energy consumption of raw material decomposition. The increase in decomposition temperature can easily cause local melting of the raw material, affecting the overall fluidity of the material, leading to thermal system disorders and posing risks to operational safety.
[0006] The above-mentioned deficiencies have also fundamentally restricted the industrialization process of cement kiln carbon dioxide capture technology and hindered the realization of carbon emission reduction targets in the cement industry.
[0007] Therefore, how to efficiently and economically capture carbon while ensuring the decomposition rate and decomposition rate of calcium carbonate in the raw material is a difficult problem that cannot be avoided in the low-carbon development of cement kilns. Utility Model Content
[0008] The technical problem to be solved by the utility model is to provide a system for capturing carbon dioxide by O2 / H2O combustion in a cement kiln in view of the deficiencies of the above-mentioned prior art. The decomposition furnace and the rotary kiln in the system for capturing carbon dioxide by O2 / H2O combustion in a cement kiln both burn in an O2 / H2O atmosphere, thereby achieving the purpose of capturing carbon dioxide during combustion and avoiding the problems of low raw material decomposition rate and high decomposition temperature under the existing O2 / CO2 combustion carbon capture technology.
[0009] In order to solve the above technical problems, the technical solution adopted by the utility model is:
[0010] A system for capturing carbon dioxide by burning O2 / H2O in a cement kiln comprises a pure oxygen supply component, a steam generator, a rotary kiln, a grate cooler, a decomposition furnace, a preheating component, a raw material supply component, a circulating fan, a pulverized coal supply component, a first carbon dioxide capture component and a second carbon dioxide capture component.
[0011] The pure oxygen supply assembly can provide pure oxygen to the rotary kiln and the decomposition furnace respectively.
[0012] The steam generator can provide steam for the rotary kiln and the decomposition furnace respectively;
[0013] The raw material supply assembly can supply cement raw meal to the calciner.
[0014] The pulverized coal supply assembly can provide pulverized coal to the rotary kiln and the decomposition furnace respectively.
[0015] The decomposition furnace can burn coal powder in an O2 / H2O atmosphere and decompose cement raw materials to form cement decomposition materials and CO2.
[0016] The rotary kiln can burn pulverized coal in an O2 / H2O atmosphere, and calcine the cement decomposition material formed by the decomposition furnace into cement clinker, and form high-temperature flue gas containing H2O and CO2.
[0017] Grate cooler is used for cooling cement clinker and has cooling air inlet and hot air outlet.
[0018] The circulating fan can form a circulating air path for the high-temperature flue gas containing H2O and CO2 generated by the rotary kiln.
[0019] The air inlet of the circulation fan is connected with the raw material supply component, the preheating component and the high-temperature flue gas outlet of the rotary kiln in sequence.
[0020] The air outlet of the circulation fan is divided into two routes, namely a first air outlet and a second air outlet; wherein the first air outlet is directly connected to the carbon dioxide capture component 1.
[0021] The second air outlet is connected to the cooling air inlet of the grate cooler.
[0022] The grate cooler has three hot air outlets, namely the first hot air outlet, the second hot air outlet and the third hot air outlet; wherein the first hot air outlet is connected to the oxygen inlet of the rotary kiln, the second hot air outlet is connected to the oxygen inlet of the decomposition furnace; the third hot air outlet is connected to the coal powder supply component and the carbon dioxide capture component 2 in sequence.
[0023] The pure oxygen supply assembly includes an air separator, an oxygen storage tank and a nitrogen storage tank; the air separator is provided with an air inlet, an O2 outlet and a N2 outlet; wherein, the air inlet of the air separator is connected to the atmosphere; the O2 outlet of the air separator is connected to the inlet of the oxygen storage tank, and the N2 outlet of the air separator is connected to the nitrogen storage tank; the oxygen outlet of the oxygen storage tank is respectively connected to the oxygen inlet of the rotary kiln and the oxygen inlet of the decomposition furnace.
[0024] The raw material supply assembly includes a raw material mill and a raw material dust collector.
[0025] The raw material mill is provided with a gas inlet, a solid inlet and a gas-solid outlet; the cement kiln raw materials are added to the solid inlet of the raw material mill.
[0026] The raw material dust collector is provided with a gas-solid inlet, a gas outlet and a solid outlet; the gas-solid inlet of the raw material dust collector is connected with the gas-solid outlet of the raw material mill; the gas outlet of the raw material dust collector is connected with the gas inlet of the circulating fan, and the solid outlet of the raw material dust collector is connected with the preheating component.
[0027] The preheating component includes a waste heat boiler and five preheaters; the five preheaters are respectively a fifth preheater, a fourth preheater, a third preheater, a second preheater and a first preheater.
[0028] The waste heat boiler is provided with a gas inlet and a gas outlet; the gas outlet of the waste heat boiler is connected with the gas inlet of the raw material mill.
[0029] The fifth preheater is provided with a gas inlet, a solid outlet and a gas outlet, and the gas outlet of the fifth preheater is connected to the gas inlet of the fourth preheater.
[0030] The fourth preheater is provided with a gas inlet, a solid outlet and a gas outlet, and the gas outlet of the fourth preheater is connected to the gas inlet of the third preheater.
[0031] The third preheater is provided with a gas inlet, a solid outlet and a gas outlet. The gas outlet of the third preheater is connected to the gas inlet of the second preheater, and the solid outlet of the third preheater is connected to the gas outlet of the fifth preheater.
[0032] The second preheater is provided with a gas inlet, a solid outlet and a gas outlet. The second preheater gas outlet is connected to the first preheater gas inlet, and the second preheater solid outlet is connected to the fourth preheater gas outlet; wherein the second preheater gas outlet is also connected to the solid outlet of the raw material dust collector.
[0033] The first preheater is provided with a gas inlet, a solid outlet and a gas outlet. The gas outlet of the first preheater is connected to the gas inlet of the waste heat boiler, and the solid outlet of the first preheater is connected to the gas outlet of the third preheater.
[0034] The decomposition furnace is provided with a fuel inlet, a gas inlet, a gas outlet, a solid inlet and a solid outlet.
[0035] The fuel inlet of the calciner is connected to the pulverized coal supply assembly.
[0036] The decomposition furnace gas outlet is connected to the fifth preheater gas inlet.
[0037] The solid inlet of the decomposition furnace is connected to the solid outlet of the fourth preheater.
[0038] The rotary kiln is provided with a rotary kiln burner, a gas outlet, a solid inlet and a solid outlet; the rotary kiln burner is connected to the coal powder supply assembly; the rotary kiln gas outlet is connected to the decomposition furnace gas inlet; the rotary kiln solid inlet is respectively connected to the decomposition furnace solid outlet and the fifth preheater solid outlet.
[0039] The pulverized coal supply components include a coal mill and a pulverized coal dust collector.
[0040] The coal mill is provided with a gas inlet, a coal feeding port and a gas-solid outlet; the coal feeding port of the coal mill is used for adding coal; the gas-solid outlet of the coal mill is connected to the inlet of the coal powder dust collector; the coal mill is provided with a gas inlet connected to the third hot air outlet of the grate cooler.
[0041] The pulverized coal dust collector is provided with an inlet, a gas outlet and a solid outlet; the gas outlet of the pulverized coal dust collector is connected to the second carbon dioxide capture component; the solid outlet of the pulverized coal dust collector is respectively connected to the inlet of the rotary kiln burner and the fuel inlet of the decomposition furnace.
[0042] The second carbon dioxide capture assembly includes a second condenser, a second water tank and a second CO2 storage tank.
[0043] The second condenser is provided with an inlet, a gas outlet and a liquid outlet; the gas outlet of the second condenser is connected to the second CO2 storage tank; the liquid outlet of the second condenser is connected to the inlet of the second water tank; the inlet of the second condenser is connected to the gas outlet of the coal powder dust collector.
[0044] The carbon dioxide capture assembly 1 includes a first condenser, a first water tank and a first CO2 storage tank.
[0045] The first condenser is provided with an inlet, a gas outlet and a liquid outlet; the first condenser gas outlet is connected to the first CO2 storage tank; the first condenser liquid outlet is connected to the first water tank inlet; the first condenser inlet is connected to the first air outlet of the circulating fan.
[0046] The first water tank is also provided with an outlet; the first water tank outlet is connected to the steam generator inlet.
[0047] The utility model has the following beneficial effects: the decomposition furnace and rotary kiln in the present application both burn in an O2 / H2O atmosphere, and while achieving the purpose of capturing carbon dioxide during combustion, the problems of low raw material decomposition rate and high decomposition temperature under the existing O2 / CO2 combustion carbon capture technology can be avoided. BRIEF DESCRIPTION OF THE DRAWINGS
[0048] Figure 1 The utility model shows a structural schematic diagram of a system for capturing carbon dioxide by O2 / H2O combustion in a cement kiln.
[0049] Among them are: 1-air separator; 2-nitrogen storage tank; 3-oxygen storage tank; 4-grate cooler; 5-steam generator; 6-coal mill; 7-rotary kiln; 8-decomposition furnace; 9-fifth preheater; 10-fourth preheater; 11-third preheater; 12-second preheater; 13-first preheater; 14-waste heat boiler; 15-raw material mill; 16-raw material dust collector; 17-circulating fan; 18-first condenser; 19-first carbon dioxide storage tank; 20-first water tank; 21-coal powder dust collector; 22-second condenser; 23-first carbon dioxide storage tank; 24-second water tank.
[0050] Among them, A-air; B-nitrogen; C-oxygen; D-coal; E-H2O / CO2 flue gas; F-cement raw meal; G-water vapor; H-cement clinker. DETAILED DESCRIPTION
[0051] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific preferred embodiments.
[0052] In the description of the present invention, it should be understood that the terms "left side", "right side", "upper part", "lower part", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. "First", "second", etc. do not indicate the importance of the components, and therefore cannot be understood as a limitation on the present invention. The specific dimensions used in this embodiment are only for illustrating the technical solution, and do not limit the scope of protection of the present invention.
[0053] like Figure 1 As shown, a system for capturing carbon dioxide by burning O2 / H2O in a cement kiln includes a pure oxygen supply component, a steam generator, a rotary kiln, a grate cooler, a decomposition furnace, a preheating component, a raw material supply component, a circulating fan, a pulverized coal supply component, a carbon dioxide capture component 1 and a carbon dioxide capture component 2.
[0054] The pure oxygen supply assembly can provide pure oxygen to the rotary kiln and the decomposition furnace respectively.
[0055] The steam generator can provide steam for the rotary kiln and the decomposition furnace respectively.
[0056] The raw material supply assembly can supply cement raw meal to the calciner.
[0057] The pulverized coal supply assembly can provide pulverized coal to the rotary kiln and the decomposition furnace respectively.
[0058] The decomposition furnace can burn coal powder in an O2 / H2O atmosphere and decompose cement raw materials to form cement decomposition materials and CO2.
[0059] The rotary kiln can burn pulverized coal in an O2 / H2O atmosphere, and calcine the cement decomposition material formed by the decomposition furnace into cement clinker, and form high-temperature flue gas containing H2O and CO2.
[0060] Grate cooler is used for cooling cement clinker and has cooling air inlet and hot air outlet.
[0061] The circulating fan can form a circulating air path for the high-temperature flue gas containing H2O and CO2 generated by the rotary kiln.
[0062] The air inlet of the circulation fan is connected with the raw material supply component, the preheating component and the high-temperature flue gas outlet of the rotary kiln in sequence.
[0063] The air outlet of the circulation fan is divided into two routes, namely a first air outlet and a second air outlet; wherein the first air outlet is directly connected to the carbon dioxide capture component 1.
[0064] The second air outlet is connected to the cooling air inlet of the grate cooler.
[0065] The grate cooler has three hot air outlets, namely the first hot air outlet, the second hot air outlet and the third hot air outlet; wherein the first hot air outlet is connected to the oxygen inlet of the rotary kiln, the second hot air outlet is connected to the oxygen inlet of the decomposition furnace; the third hot air outlet is connected to the coal powder supply component and the carbon dioxide capture component 2 in sequence.
[0066] The pure oxygen supply assembly includes an air separator, an oxygen storage tank and a nitrogen storage tank; the air separator is provided with an air inlet, an O2 outlet and a N2 outlet; wherein, the air inlet of the air separator is connected to the atmosphere; the O2 outlet of the air separator is connected to the inlet of the oxygen storage tank, and the N2 outlet of the air separator is connected to the nitrogen storage tank; the oxygen outlet of the oxygen storage tank is respectively connected to the oxygen inlet of the rotary kiln and the oxygen inlet of the decomposition furnace.
[0067] The raw material supply assembly includes a raw material mill and a raw material dust collector.
[0068] The raw material mill is provided with a gas inlet, a solid inlet and a gas-solid outlet; the cement kiln raw materials are added to the solid inlet of the raw material mill.
[0069] The raw material dust collector is provided with a gas-solid inlet, a gas outlet and a solid outlet; the gas-solid inlet of the raw material dust collector is connected with the gas-solid outlet of the raw material mill; the gas outlet of the raw material dust collector is connected with the gas inlet of the circulating fan, and the solid outlet of the raw material dust collector is connected with the preheating component.
[0070] The preheating component includes a waste heat boiler and five preheaters; the five preheaters are respectively a fifth preheater, a fourth preheater, a third preheater, a second preheater and a first preheater.
[0071] The waste heat boiler is provided with a gas inlet and a gas outlet; the gas outlet of the waste heat boiler is connected with the gas inlet of the raw material mill.
[0072] The fifth preheater is provided with a gas inlet, a solid outlet and a gas outlet, and the gas outlet of the fifth preheater is connected to the gas inlet of the fourth preheater.
[0073] The fourth preheater is provided with a gas inlet, a solid outlet and a gas outlet, and the gas outlet of the fourth preheater is connected to the gas inlet of the third preheater.
[0074] The third preheater is provided with a gas inlet, a solid outlet and a gas outlet. The gas outlet of the third preheater is connected to the gas inlet of the second preheater, and the solid outlet of the third preheater is connected to the gas outlet of the fifth preheater.
[0075] The second preheater is provided with a gas inlet, a solid outlet and a gas outlet. The second preheater gas outlet is connected to the first preheater gas inlet, and the second preheater solid outlet is connected to the fourth preheater gas outlet; wherein the second preheater gas outlet is also connected to the solid outlet of the raw material dust collector.
[0076] The first preheater is provided with a gas inlet, a solid outlet and a gas outlet. The gas outlet of the first preheater is connected to the gas inlet of the waste heat boiler, and the solid outlet of the first preheater is connected to the gas outlet of the third preheater.
[0077] The decomposition furnace is provided with a fuel inlet, a gas inlet, a gas outlet, a solid inlet and a solid outlet.
[0078] The fuel inlet of the calciner is connected to the pulverized coal supply assembly.
[0079] The decomposition furnace gas outlet is connected to the fifth preheater gas inlet.
[0080] The solid inlet of the decomposition furnace is connected to the solid outlet of the fourth preheater.
[0081] The rotary kiln is provided with a rotary kiln burner, a gas outlet, a solid inlet and a solid outlet; the rotary kiln burner is connected to the coal powder supply assembly; the rotary kiln gas outlet is connected to the decomposition furnace gas inlet; the rotary kiln solid inlet is respectively connected to the decomposition furnace solid outlet and the fifth preheater solid outlet.
[0082] The pulverized coal supply components include a coal mill and a pulverized coal dust collector.
[0083] The coal mill is provided with a gas inlet, a coal feeding port and a gas-solid outlet; the coal feeding port of the coal mill is used for adding coal; the gas-solid outlet of the coal mill is connected to the inlet of the coal powder dust collector; the coal mill is provided with a gas inlet connected to the third hot air outlet of the grate cooler.
[0084] The pulverized coal dust collector is provided with an inlet, a gas outlet and a solid outlet; the gas outlet of the pulverized coal dust collector is connected to the second carbon dioxide capture component; the solid outlet of the pulverized coal dust collector is respectively connected to the inlet of the rotary kiln burner and the fuel inlet of the decomposition furnace.
[0085] The second carbon dioxide capture assembly includes a second condenser, a second water tank and a second CO2 storage tank.
[0086] The second condenser is provided with an inlet, a gas outlet and a liquid outlet; the gas outlet of the second condenser is connected to the second CO2 storage tank; the liquid outlet of the second condenser is connected to the inlet of the second water tank; the inlet of the second condenser is connected to the gas outlet of the coal powder dust collector.
[0087] The carbon dioxide capture assembly 1 includes a first condenser, a first water tank and a first CO2 storage tank.
[0088] The first condenser is provided with an inlet, a gas outlet and a liquid outlet; the first condenser gas outlet is connected to the first CO2 storage tank; the first condenser liquid outlet is connected to the first water tank inlet; the first condenser inlet is connected to the first air outlet of the circulating fan.
[0089] The first water tank is also provided with an outlet; the first water tank outlet is connected to the steam generator inlet.
[0090] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical scheme of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.
Claims
1. A system for capturing carbon dioxide by O2 / H2O combustion in a cement kiln, characterized in that: It includes a pure oxygen supply component, a steam generator, a rotary kiln, a grate cooler, a decomposition furnace, a preheating component, a raw material supply component, a circulating fan, a pulverized coal supply component, a carbon dioxide capture component 1 and a carbon dioxide capture component 2; The pure oxygen supply component can provide pure oxygen to the rotary kiln and the decomposition furnace respectively; The steam generator can provide steam for the rotary kiln and the decomposition furnace respectively; The raw material supply assembly can supply cement raw meal to the calciner; The pulverized coal supply assembly can provide pulverized coal to the rotary kiln and the decomposition furnace respectively; The calciner can burn the pulverized coal in an O2 / H2O atmosphere and decompose the cement raw material to form cement decomposer and CO2; The rotary kiln can burn pulverized coal in an O2 / H2O atmosphere, calcine the cement decomposition material formed by the decomposition furnace into cement clinker, and form high-temperature flue gas containing H2O and CO2; The grate cooler is used for cooling cement clinker and has a cooling air inlet and a hot air outlet; The circulating fan can form a circulating air path for the high-temperature flue gas containing H2O and CO2 generated by the rotary kiln; The air inlet of the circulation fan is connected to the raw material supply component, the preheating component and the high-temperature flue gas outlet of the rotary kiln in sequence; The air outlet of the circulation fan is divided into two routes, namely the first air outlet and the second air outlet; wherein the first air outlet is directly connected to the carbon dioxide capture component 1; The second air outlet is connected to the cooling air inlet of the grate cooler; The grate cooler has three hot air outlets, namely the first hot air outlet, the second hot air outlet and the third hot air outlet; wherein the first hot air outlet is connected to the oxygen inlet of the rotary kiln, the second hot air outlet is connected to the oxygen inlet of the decomposition furnace; the third hot air outlet is connected to the coal powder supply component and the carbon dioxide capture component 2 in sequence.
2. The system for capturing carbon dioxide by O2 / H2O combustion in a cement kiln according to claim 1, characterized in that: The pure oxygen supply assembly includes an air separator, an oxygen storage tank and a nitrogen storage tank; the air separator is provided with an air inlet, an O2 outlet and a N2 outlet; wherein, the air inlet of the air separator is connected to the atmosphere; the O2 outlet of the air separator is connected to the inlet of the oxygen storage tank, and the N2 outlet of the air separator is connected to the nitrogen storage tank; the oxygen outlet of the oxygen storage tank is respectively connected to the oxygen inlet of the rotary kiln and the oxygen inlet of the decomposition furnace.
3. The system for capturing carbon dioxide by O2 / H2O combustion in a cement kiln according to claim 1, characterized in that: The raw material supply assembly includes a raw material mill and a raw material dust collector; The raw material mill is equipped with a gas inlet, a solid inlet, and a gas-solid outlet; the solid inlet of the raw material mill is used to add cement kiln raw materials; The raw material dust collector is provided with a gas-solid inlet, a gas outlet and a solid outlet; the gas-solid inlet of the raw material dust collector is connected with the gas-solid outlet of the raw material mill; the gas outlet of the raw material dust collector is connected with the gas inlet of the circulating fan, and the solid outlet of the raw material dust collector is connected with the preheating component.
4. The system for capturing carbon dioxide by O2 / H2O combustion in a cement kiln according to claim 3, characterized in that: The preheating assembly includes a waste heat boiler and five preheaters; the five preheaters are respectively a fifth preheater, a fourth preheater, a third preheater, a second preheater and a first preheater; The waste heat boiler is provided with a gas inlet and a gas outlet; the gas outlet of the waste heat boiler is connected to the gas inlet of the raw material mill; The fifth preheater is provided with a gas inlet, a solid outlet and a gas outlet, and the gas outlet of the fifth preheater is connected to the gas inlet of the fourth preheater; The fourth preheater is provided with a gas inlet, a solid outlet and a gas outlet, and the gas outlet of the fourth preheater is connected to the gas inlet of the third preheater; The third preheater is provided with a gas inlet, a solid outlet and a gas outlet, the gas outlet of the third preheater is connected to the gas inlet of the second preheater, and the solid outlet of the third preheater is connected to the gas outlet of the fifth preheater; The second preheater is provided with a gas inlet, a solid outlet and a gas outlet, the gas outlet of the second preheater is connected to the gas inlet of the first preheater, and the solid outlet of the second preheater is connected to the gas outlet of the fourth preheater; wherein the gas outlet of the second preheater is also connected to the solid outlet of the raw material dust collector; The first preheater is provided with a gas inlet, a solid outlet and a gas outlet. The gas outlet of the first preheater is connected to the gas inlet of the waste heat boiler, and the solid outlet of the first preheater is connected to the gas outlet of the third preheater.
5. The system for capturing carbon dioxide by O2 / H2O combustion in a cement kiln according to claim 4, characterized in that: The decomposition furnace is provided with a fuel inlet, a gas inlet, a gas outlet, a solid inlet and a solid outlet; The fuel inlet of the calciner is connected to the pulverized coal supply assembly; The decomposition furnace gas outlet is connected to the fifth preheater gas inlet; The solid inlet of the decomposition furnace is connected to the solid outlet of the fourth preheater.
6. The system for capturing carbon dioxide by O2 / H2O combustion in a cement kiln according to claim 5, characterized in that: The rotary kiln is provided with a rotary kiln burner, a gas outlet, a solid inlet and a solid outlet; the rotary kiln burner is connected to the coal powder supply assembly; the rotary kiln gas outlet is connected to the decomposition furnace gas inlet; the rotary kiln solid inlet is respectively connected to the decomposition furnace solid outlet and the fifth preheater solid outlet.
7. The system for capturing carbon dioxide by O2 / H2O combustion in a cement kiln according to claim 6, characterized in that: The pulverized coal supply components include a coal mill and a pulverized coal dust collector; The coal mill is provided with a gas inlet, a coal feeding port and a gas-solid outlet; the coal feeding port of the coal mill is used to add coal; the gas-solid outlet of the coal mill is connected to the inlet of the coal powder dust collector; the coal mill is provided with a gas inlet connected to the third hot air outlet of the grate cooler; The pulverized coal dust collector is provided with an inlet, a gas outlet and a solid outlet; the gas outlet of the pulverized coal dust collector is connected to the second carbon dioxide capture component; the solid outlet of the pulverized coal dust collector is respectively connected to the inlet of the rotary kiln burner and the fuel inlet of the decomposition furnace.
8. The system for capturing carbon dioxide by O2 / H2O combustion in a cement kiln according to claim 7, characterized in that: The second carbon dioxide capture assembly includes a second condenser, a second water tank, and a second CO2 storage tank; The second condenser is provided with an inlet, a gas outlet and a liquid outlet; the gas outlet of the second condenser is connected to the second CO2 storage tank; The liquid outlet of the second condenser is connected to the inlet of the second water tank; the inlet of the second condenser is connected to the gas outlet of the coal powder dust collector.
9. The system for capturing carbon dioxide by O2 / H2O combustion in a cement kiln according to claim 1, characterized in that: The carbon dioxide capture assembly 1 includes a first condenser, a first water tank and a first CO2 storage tank; The first condenser is provided with an inlet, a gas outlet and a liquid outlet; the gas outlet of the first condenser is connected to the first CO2 storage tank; The first condenser liquid outlet is connected to the first water tank inlet; the first condenser inlet is connected to the first air outlet of the circulating fan.
10. The system for capturing carbon dioxide by O2 / H2O combustion in a cement kiln according to claim 9, characterized in that: The first water tank is also provided with an outlet; the first water tank outlet is connected to the steam generator inlet.