Cement production system

Abstract

Embodiments of the present invention disclose a cement production system, a preheating assembly of the system has a first inlet for receiving cement raw materials and a first outlet for discharging the cement raw materials preheated by the preheating assembly; a first cylinder is in communication with the first outlet to receive the preheated cement raw materials discharged from the preheating assembly, a combustion assembly is arranged on the outer wall of the first cylinder, the combustion assembly is used for heating and decomposing calcium carbonate in the cement raw materials into semi-clinker and carbon dioxide gas, the first cylinder has a second outlet for discharging the semi-clinker and a third outlet for discharging the carbon dioxide gas; a part of a sintering assembly is in communication with the second outlet to receive the semi-clinker discharged from the first cylinder and sinter the semi-clinker into clinker; a carbon capture assembly is in communication with the third outlet to receive the carbon dioxide gas discharged from the first cylinder and capture and recycle the carbon dioxide gas. The cement production system of the embodiments of the present invention significantly reduces the energy consumption of carbon capture.

Description

Technical Field

[0001] This invention relates to the field of cement production technology, and more specifically to a cement production system. Background Technology

[0002] Cement production is one of the major sources of global carbon emissions, primarily from "process emissions" of limestone decomposition and "energy emissions" of fuel combustion. Current mainstream dry-process cement production tightly couples raw material decomposition and fuel combustion within a precalciner, resulting in a high degree of mixing between process-emitted CO2 and combustion flue gas. This leads to low CO2 concentrations (typically below 30%) and complex composition in the flue gas, necessitating the processing of massive amounts of mixed gas for subsequent carbon capture, utilization, and storage (CCUS), which presents challenges such as high energy consumption, large equipment size, and high costs. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the related art.

[0004] Therefore, embodiments of the present invention propose a cement production system that can directly process high-purity carbon dioxide gas, significantly reducing the amount of gas processed by the carbon capture system, reducing equipment size and energy consumption. Due to the high concentration and simple composition of carbon dioxide gas, the energy consumption of carbon capture is significantly reduced.

[0005] The cement production system of this invention includes a preheating component, a first cylinder, a combustion component, a calcination component, and a carbon capture component. The preheating component has a first inlet and a first outlet. The first inlet is used to receive cement raw meal, and the first outlet is used to discharge the cement raw meal preheated by the preheating component. The first cylinder is connected to the first outlet to receive the preheated cement raw meal discharged from the preheating component. The combustion component is disposed on the outer wall of the first cylinder and is used to heat and decompose calcium carbonate in the cement raw meal entering the first cylinder into semi-clinker and carbon dioxide gas. The first cylinder has a second outlet for discharging semi-clinker and a third outlet for discharging carbon dioxide gas. A portion of the calcination component is connected to the second outlet to receive the semi-clinker discharged from the first cylinder and calcinate it into clinker. The carbon capture component is connected to the third outlet to receive and capture and recover the carbon dioxide gas discharged from the first cylinder.

[0006] In the cement production system of this invention, the raw cement meal first enters the preheating assembly for preheating to improve the energy efficiency of the subsequent decomposition process. The preheated raw meal then enters the first cylinder and is heated by a combustion assembly located on the outer wall of the cylinder. The key to this design is placing the combustion assembly on the outside of the first cylinder, so that the flue gas generated by combustion is separated from the carbon dioxide gas generated by the decomposition of calcium carbonate. The first cylinder has two outlets: the second outlet discharges the semi-cooked meal after decomposition, and the third outlet is specifically for discharging the carbon dioxide gas generated by the decomposition of calcium carbonate. The semi-cooked meal enters the calcining assembly through the second outlet and is finally calcined into clinker. The high concentration of carbon dioxide gas directly enters the carbon capture assembly through the third outlet for capture and recovery.

[0007] Compared to related technologies, this method achieves high-concentration carbon dioxide emissions by separating the raw material decomposition and fuel combustion processes. This avoids the mixing of carbon dioxide with combustion flue gas in traditional processes, allowing the carbon capture unit to directly process high-purity carbon dioxide. This significantly reduces the gas volume processed by the carbon capture system, decreasing equipment size and energy consumption. Due to the high concentration and simple composition of carbon dioxide, the energy consumption of carbon capture is significantly reduced. The combustion unit is located on the outside of the cylinder, resulting in more efficient heat utilization, and the preheating unit improves overall energy efficiency.

[0008] In some embodiments, the cement production system of the present invention further includes a first pipeline and a second pipeline. The first pipeline is connected between the third outlet and the carbon capture component to introduce carbon dioxide gas into the carbon capture component. One end of the second pipeline is connected to the first pipeline, and the other end of the second pipeline is connected to the first cylinder to circulate a portion of the carbon dioxide gas in the first pipeline into the first cylinder.

[0009] In some embodiments, the second pipeline of the cement production system of the present invention has a gas inlet for replenishing and delivering carbon dioxide gas into the first cylinder.

[0010] In some embodiments, the calcination component of the cement production system of the present invention includes a rotary kiln connected to a second outlet to receive semi-clinker discharged from the first cylinder and calcinate it into clinker.

[0011] In some embodiments, the calcination component of the cement production system of the present invention further includes a grate cooler, which is connected to the rotary kiln for receiving and cooling clinker discharged from the rotary kiln.

[0012] In some embodiments, the cement production system of the present invention further includes a third pipe body, which is connected between the grate cooler and the combustion assembly, for introducing hot air heated by high-temperature clinker in the grate cooler into the combustion assembly.

[0013] In some embodiments, the preheating component of the cement production system of the present invention has a second inlet, and the combustion component has a fourth outlet, the fourth outlet being connected to the second inlet for sending hot flue gas generated by combustion in the combustion component into the preheating component.

[0014] In some embodiments, the cement production system of the present invention further includes a second cylinder, wherein the first cylinder is sleeved on the second cylinder to form an annular jacket structure between the second cylinder and the first cylinder, and the combustion assembly is disposed between the second cylinder and the first cylinder.

[0015] In some embodiments, the combustion assembly of the cement production system of the present invention has a third inlet for injecting fuel into the combustion assembly.

[0016] In some embodiments, the external heat source for the combustion component of the cement production system of the present invention may be either pulverized coal or natural gas. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the cement production system according to an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the second inlet of the cement production system according to an embodiment of the present invention.

[0019] Reference numerals: 1. Preheating assembly; 101. First inlet; 102. First outlet; 103. Second inlet; 2. First cylinder; 201. Second outlet; 202. Third outlet; 3. Combustion assembly; 301. Fourth outlet; 302. Third inlet; 4. Firing assembly; 401. Rotary kiln; 402. Grate cooler; 5. Carbon capture assembly; 6. First pipeline; 7. Second pipeline; 701. Gas inlet; 8. Third pipe; 9. Second cylinder. Detailed Implementation

[0020] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0021] Reference Figures 1-2As shown, the cement production system of this embodiment includes a preheating component 1, a first cylinder 2, a combustion component 3, a calcination component 4, and a carbon capture component 5. The preheating component 1 has a first inlet 101 and a first outlet 102. The first inlet 101 is used to receive cement raw meal, and the first outlet 102 is used to discharge the cement raw meal preheated by the preheating component 1. The first cylinder 2 is connected to the first outlet 102 to receive the preheated cement raw meal discharged from the preheating component 1. The combustion component 3 is disposed on the outer wall of the first cylinder 2 and is used to heat and decompose the calcium carbonate in the cement raw meal introduced into the first cylinder 2 into semi-clinker and carbon dioxide gas. The first cylinder 2 has a second outlet 201 for discharging semi-clinker and a third outlet 202 for discharging carbon dioxide gas. A portion of the calcination component 4 is connected to the second outlet 201 to receive the semi-clinker discharged from the first cylinder 2 and calcinate it into clinker. The carbon capture component 5 is connected to the third outlet 202 to receive and capture and recover the carbon dioxide gas discharged from the first cylinder 2.

[0022] In the cement production system of this embodiment, the cement raw meal first enters the preheating component 1 for preheating to improve the energy efficiency of the subsequent decomposition process. The preheated raw meal then enters the first cylinder 2 and is heated by the combustion component 3 located on the outer wall of the cylinder. The key to this design is placing the combustion component 3 on the outside of the first cylinder 2, so that the flue gas generated by combustion is separated from the carbon dioxide gas generated by the decomposition of calcium carbonate. The first cylinder 2 has two outlets: the second outlet 201 discharges the semi-cooked meal after decomposition, and the third outlet 202 is specifically for discharging the carbon dioxide gas generated by the decomposition of calcium carbonate. The semi-cooked meal enters the calcining component 4 through the second outlet 201 and is finally calcined into clinker. The high concentration of carbon dioxide gas directly enters the carbon capture component 5 through the third outlet 202 for capture and recovery.

[0023] Compared with related technologies, by separating the raw material decomposition and fuel combustion processes, high-concentration carbon dioxide emissions are achieved, avoiding the mixing of carbon dioxide with combustion flue gas in traditional processes. This allows the carbon capture component 5 to directly process high-purity carbon dioxide, significantly reducing the gas volume processed by the carbon capture system, reducing equipment size and energy consumption. Due to the high concentration and simple composition of carbon dioxide, the energy consumption of carbon capture is significantly reduced. The combustion component 3 is located on the outside of the cylinder, making heat utilization more efficient, and the preheating component 1 improves the overall energy utilization efficiency.

[0024] Optionally, the preheating component 1 is mainly a raw material preheater, used to preheat the raw material.

[0025] In some embodiments, such as Figures 1-2As shown, the cement production system of this embodiment of the invention also includes a first pipeline 6 and a second pipeline 7. The first pipeline 6 is connected between the third outlet 202 and the carbon capture assembly 5 to introduce carbon dioxide gas into the carbon capture assembly 5. One end of the second pipeline 7 is connected to the first pipeline 6, and the other end of the second pipeline 7 is connected to the first cylinder 2 to circulate a portion of the carbon dioxide gas in the first pipeline 6 into the first cylinder 2. The system guides the carbon dioxide gas generated during the production process from the third outlet 202 to the carbon capture assembly 5 through the first pipeline 6. The second pipeline 7 realizes the internal circulation of part of the carbon dioxide, reintroducing a portion of the captured gas into the first cylinder 2. This method captures carbon dioxide while retaining a portion of the gas for optimizing the production process. This circulation loop pressurizes a portion of the CO2 gas flow through a fan and adjusts it to a suitable temperature before reintroducing it into the rotary decomposition zone of the first cylinder 2 as a protective gas to prevent air infiltration, while simultaneously enhancing gas flow within the kiln and improving heat transfer efficiency.

[0026] The system realizes carbon capture and partial recycling in the cement production process, embodying the concept of circular economy, while taking into account both environmental protection and production efficiency, thus achieving dual benefits.

[0027] In some embodiments, such as Figures 1-2 As shown, the second pipeline 7 of the cement production system in this embodiment of the invention has a gas inlet 701 for supplying carbon dioxide gas to the first cylinder 2.

[0028] During the initial operation of the system, the CO2 concentration inside the first cylinder 2 is very low, and CO2 circulation has not yet been established. Therefore, a certain amount of CO2 needs to be added to the system through gas inlet 701 until the CO2 concentration in the gas output to the carbon capture assembly 5 reaches a higher level. Simultaneously, after the system reaches a stable state, gas leakage may occur. To maintain system stability, gas can be added through gas inlet 701 to compensate for this loss.

[0029] In some embodiments, such as Figures 1-2 As shown, the calcination component 4 of the cement production system in this embodiment of the invention includes a rotary kiln 401. The rotary kiln 401 is connected to a second outlet 201 to receive the semi-clinker discharged from the first cylinder 2 and sinter it into clinker. The rotary kiln 401 is used to receive the semi-clinker after reaction and decomposition, and further complete the cement sintering process at about 1450°C to form cement clinker.

[0030] In some embodiments, such as Figures 1-2As shown, the calcination component 4 of the cement production system in this embodiment of the invention further includes a grate cooler 402. The grate cooler 402 is connected to the rotary kiln 401 to receive and cool the clinker discharged from the rotary kiln 401. The outlet of the rotary kiln 401 is connected to the inlet of the grate cooler 402. The sintered clinker enters the grate cooler 402 for cooling, and the grate cooler 402 can produce sintered cement clinker.

[0031] In some embodiments, such as Figures 1-2 As shown, the cement production system of this embodiment of the invention also includes a third pipe 8, which connects the grate cooler 402 and the combustion assembly 3, for introducing hot air heated by the high-temperature clinker in the grate cooler 402 into the combustion assembly 3. The high-temperature clinker in the grate cooler 402 is rapidly cooled by the cold air, and the temperature of the cold air after heating can reach 800-1200 ℃. This portion of hot air is sent from the third pipe 8 into the combustion assembly 3 to assist the combustion of fuel in the combustion assembly 3.

[0032] In some embodiments, such as Figures 1-2 As shown, the preheating component 1 of the cement production system in this embodiment of the invention has a second inlet 103, and the combustion component 3 has a fourth outlet 301. The fourth outlet 301 is connected to the second inlet 103 to send the hot flue gas generated by combustion in the combustion component 3 into the preheating component 1. The hot flue gas generated by combustion in the combustion component 3 is extracted from the fourth outlet 301 and sent into the preheating component 1 through the second inlet 103. The flue gas moves from bottom to top and exchanges heat with the raw material in a countercurrent manner, so that the temperature of the raw material in the preheating component 1 reaches about 800°C.

[0033] In some embodiments, such as Figures 1-2As shown, the cement production system of this embodiment of the invention also includes a second cylinder 9, with a first cylinder 2 fitted onto the second cylinder 9 to form an annular jacket structure between the second cylinder 9 and the first cylinder 2. A combustion assembly 3 is disposed between the second cylinder 9 and the first cylinder 2. The second cylinder 9 and the first cylinder 2 constitute a pre-decomposition module. The core of the pre-decomposition module is a jacketed external heating rotary kiln 401, which is divided into a second cylinder 9 and a first cylinder 2. The interior of the first cylinder 2 is a rotary decomposition zone, which is a sealed material channel. The second cylinder 9 is a fixed structure, forming an annular jacket structure with the first cylinder 2. The combustion assembly 3 is arranged between the first cylinder 2 and the second cylinder 9, physically isolated from the inner cylinder rotary decomposition zone. Combustion assembly 3 injects fuel and burns it in the combustion zone to heat rotary kiln 401. The heat is efficiently conducted through the inner cylinder wall to the internal rotary decomposition zone, where the raw material is rapidly and uniformly heated to 850-950℃. Calcium carbonate in the raw material decomposes rapidly within minutes, with a decomposition rate exceeding 95%. Through the jacketed external heating rotary kiln 401 design, pure collection of process-emitted CO2 is achieved, with a concentration exceeding 90%, reducing subsequent carbon capture energy consumption and costs by more than 60% compared to traditional technologies.

[0034] In some embodiments, such as Figures 1-2 As shown, the combustion assembly 3 of the cement production system in this embodiment of the invention has a third inlet 302, which is used to inject fuel into the combustion assembly 3. Combustion in the combustion assembly 3 heats the first cylinder 2, and the heat is efficiently conducted through the cylinder wall of the first cylinder 2 to the internal rotary decomposition zone. The raw material in the decomposition zone is rapidly and uniformly heated to 850-950°C, and the calcium carbonate in the raw material decomposes rapidly within minutes, with a decomposition rate of over 95%.

[0035] In some embodiments, such as Figures 1-2 As shown, the external heat source of the combustion component 3 of the cement production system in this embodiment of the invention can be either pulverized coal or natural gas, to meet actual production needs.

[0036] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0038] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0039] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0040] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0041] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A cement production system, characterized in that, include: A preheating assembly (1) has a first inlet (101) and a first outlet (102), the first inlet (101) being used to receive cement raw meal, and the first outlet (102) being used to discharge cement raw meal preheated by the preheating assembly (1); The first cylinder (2) and the combustion assembly (3) are connected to the first outlet (102) to receive preheated cement raw material discharged from the preheating assembly (1). The combustion assembly (3) is disposed on the outer wall of the first cylinder (2). The combustion assembly (3) is used to heat and decompose calcium carbonate in the cement raw material introduced into the first cylinder (2) into semi-clinker and carbon dioxide gas. The first cylinder (2) has a second outlet (201) for discharging semi-clinker and a third outlet (202) for discharging carbon dioxide gas. A sintering assembly (4), a portion of which is connected to the second outlet (201) for receiving semi-cooked material discharged from the first cylinder (2) and sintering it into cooked material; A carbon capture assembly (5) is connected to the third outlet (202) for receiving and capturing carbon dioxide gas emitted from the first cylinder (2).

2. The cement production system according to claim 1, characterized in that, Also includes: The first pipeline (6) is connected between the third outlet (202) and the carbon capture assembly (5) to introduce carbon dioxide gas into the carbon capture assembly (5). The second pipeline (7) has one end connected to the first pipeline (6) and the other end connected to the first cylinder (2) to circulate some of the carbon dioxide gas in the first pipeline (6) into the first cylinder (2).

3. The cement production system according to claim 2, characterized in that, The second pipeline (7) has a gas inlet (701) for supplying carbon dioxide gas into the first cylinder (2).

4. The cement production system according to claim 1, characterized in that, The firing assembly (4) includes a rotary kiln (401) connected to the second outlet (201) to receive semi-cooked material discharged from the first cylinder (2) and sinter it into cooked material.

5. The cement production system according to claim 4, characterized in that, The firing assembly (4) also includes a grate cooler (402) connected to the rotary kiln (401) for receiving and cooling the clinker discharged from the rotary kiln (401).

6. The cement production system according to claim 5, characterized in that, It also includes a third tube (8) which is connected between the grate cooler (402) and the combustion assembly (3) for introducing hot air heated by high-temperature clinker in the grate cooler (402) into the combustion assembly (3).

7. The cement production system according to claim 1, characterized in that, The preheating component (1) has a second inlet (103), and the combustion component (3) has a fourth outlet (301), which is connected to the second inlet (103) for feeding hot flue gas generated by combustion in the combustion component (3) into the preheating component (1).

8. The cement production system according to claim 1, characterized in that, It also includes a second cylinder (9), the first cylinder (2) being sleeved on the second cylinder (9) to form an annular jacket structure between the second cylinder (9) and the first cylinder (2), and the combustion assembly (3) being disposed between the second cylinder (9) and the first cylinder (2).

9. The cement production system according to claim 1, characterized in that, The combustion assembly (3) has a third inlet (302) for injecting fuel into the combustion assembly (3).

10. The cement production system according to any one of claims 1-9, characterized in that, The external heat source of the combustion assembly (3) can be either pulverized coal or natural gas.

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