Apparatus and method for manufacturing cement and separating carbon dioxide

Abstract

The present invention relates to a method and corresponding equipment for manufacturing cement clinker (110) from raw meal (120), the method comprising the following steps: preheating (10) the raw meal (120) to make it hot feed (122), separating (20) the hot feed (122) in a cyclone separator (161), introducing the hot feed (122) into a fluidized bed reactor (170) through a hot feed pipeline (163), calcining (30) the hot feed (122) in the fluidized bed reactor (170) as a calciner to make it deacidified raw meal (121), separating (40) the deacidified raw meal (121) in a cyclone separator (177) following the fluidized bed reactor (170) as a calciner in the gas flow direction, and sintering (50) the separated deacidified raw meal (121) in a rotary kiln (130) to make it cement clinker (110). According to the present invention, the raw material (120) is preheated (10) in the fluidized bed reactor (160) which is the first fluidized bed reactor, and is made into a hot material (122), and the exhaust gas of the rotary kiln (130) is applied to the first fluidized bed reactor (160) (55).

Description

Technical Field

[0001] This invention relates to a method and corresponding equipment for manufacturing cement clinker from raw materials. The method comprises the following steps: preheating the raw materials to make them hot materials; separating the hot materials in a cyclone separator; introducing the hot materials into a fluidized bed reactor through a hot material pipeline; calcining the hot materials in the fluidized bed reactor, which serves as a calciner, to make them deacidified raw materials; separating the deacidified raw materials in a cyclone separator following the fluidized bed reactor, which serves as a calciner, in the direction of gas flow; and sintering the separated deacidified raw materials in a rotary kiln to make them cement clinker. Background Technology

[0002] In the known process of manufacturing cement clinker from raw materials composed of silicate and carbonate rock aggregates, carbon dioxide (CO2) is similarly generated from two unrelated sources. On one hand, CO2 is produced during the combustion of fossil fuels and also during the combustion of alternative secondary fuels used in highly endothermic processes; on the other hand, CO2 is produced during the calcination of carbonate rock aggregates, where CO2 is expelled from the carbonates to obtain quicklime (CaO) as an intermediate product. CO2 from both sources is conventionally released into the open atmosphere as exhaust gas. The amount of CO2 in Earth's atmosphere has been identified as a cause of currently observed climate change on Earth. Therefore, current efforts are focused on preventing or at least reducing CO2 emissions into the atmosphere.

[0003] Separating carbon dioxide (CO2) from waste gas is a highly endothermic process and requires thermal energy. Therefore, it is conceivable to use the waste heat from cement production to perform CO2 separation. However, the available waste heat in cement clinker manufacturing is insufficient to separate all the CO2. Cement production using current methods produces more CO2 than can be separated by the available waste heat. One possibility for obtaining the missing thermal energy is to use a heat pump. However, heat pumps require electricity to operate, and the conversion of electricity from thermal energy is inefficient. Another possibility for generating the necessary thermal energy for separating and storing CO2 is a separate hot gas generator, but this incurs additional equipment costs and generates additional CO2 when operating with fossil fuels, with fuel ash accumulating as waste. This waste itself poses a disposal problem. Therefore, it is necessary to design the hot gas generator to minimize the accumulation of problematic ash as waste. The setup and operation of such equipment is also economically costly. Summary of the Invention

[0004] Therefore, the object of this invention is to modify known methods for manufacturing cement clinker to ensure sufficient waste heat is available during the manufacturing process. Conventional methods for manufacturing cement clinker aim to optimize the entire process to generate as little or no associated waste heat as possible, since heat loss is associated with lower economic efficiency. The object of this invention anticipates the opposite: the method discards as much waste heat as possible that could be used to operate a carbon dioxide (CO2) separation process. If known methods for manufacturing cement clinker are modified to generate as much waste heat as possible, then other process features that would render ash post-processing redundant can be utilized. The proposed method fundamentally changes the requirements for process design. If associated waste heat should have been avoided as much as possible previously, then now the equivalent amount of waste heat required for CO2 separation from the exhaust gas should be purposefully generated. Nevertheless, the manufacturing of cement clinker remains the primary objective.

[0005] The initial understanding is that it is impossible to operate known equipment for manufacturing cement clinker with excessive fuel and the associated excessive waste heat, as this could lead to equipment overheating. The solution to the problem of the present invention lies in altering the known manufacturing process, which consists of preheating raw meal, calcining preheated raw meal, sintering raw meal, and subsequently cooling and sintering cement clinker, so that the waste heat generated during cooling and in the sintering furnace is not used for the endothermic calcination stage, and the waste heat generated during calcination is not redirected for preheating. Instead, this waste heat is first used for preheating, and only after this is the excess heat applied to calcination, wherein any remaining heat energy is subsequently added for calcination by burning, preferably waste-based, secondary fuel. According to the concept of the invention, the order of waste heat utilization during preheating, calcination, and sintering is changed. This firstly makes operation with a larger excess fuel possible, thereby generating as much waste heat as possible. Specifically, the problem of the invention is solved by preheating a portion of the raw meal in a fluidized bed reactor, which serves as a first fluidized bed reactor, and by applying hot waste gas from a rotary kiln to this first fluidized bed reactor. Other advantageous designs of this method are given in the dependent claims of claim 1. The method according to the invention can be implemented in the apparatus according to claim 10. Other advantageous designs of this apparatus are given in the dependent claims of claim 10.

[0006] To achieve the ideal implementation of the concept according to the invention, it is advantageous to replace the well-established cyclone heat exchanger with a fluidized bed reactor, which functions as a preheater. Two requirements exist for the calcination in the subsequent reactor, originating from both the gas flow direction and the waste heat flow direction. The temperature necessary for igniting the fuel there must be transferred to the feed stream in the first fluidized bed reactor, which acts as a heat carrier in this second step, thereby enabling ignition of the fuel in the subcooled atmosphere composed of raw material, air, and oxygen. A long residence time in the fluidized bed reactor, which functions as a calciner, is necessary to heat the tertiary air, fuel, and raw materials, and to achieve complete combustion, whereby the heat used for preheating can optionally be extracted from the tertiary air. Those skilled in the art can achieve these requirements through corresponding optimization designs of the method.

[0007] Besides the method of reversing the gas flow direction and waste heat flow direction, the waste heat from the rotary kiln is first used to preheat the material in the preheating section (20-50%) and the remaining heat is used for CO2 separation. According to the invention, there is also the possibility of generating more waste heat in this method, namely, cooling cement clinker in a clinker cooler connected to the rotary kiln in the material flow direction, and introducing heated cooling air (as tertiary air) from the cooler head shell of the clinker cooler through a tertiary air pipeline into a second fluidized bed reactor that functions as a calciner. The heat energy in the tertiary air is then used to ignite fuel during calcination. To further increase the availability of waste heat, waste heat can be extracted from the tertiary air through a heat exchanger connected to the tertiary air pipeline. The tertiary air carries high heat, which can be well utilized as operating energy in other methods of carbon dioxide (CO2) separation. The tertiary air is intensely cooled here. To offset this heat loss, far more fuel can now be added to the fluidized bed reactor that functions as a calciner.

[0008] To utilize more waste heat from cement clinker manufacturing processes, waste heat can be extracted from heated, cooled air (which serves as exhaust air) via a heat exchanger connected to a gas line used to remove the exhaust air from the cooler. This waste heat is low-temperature and suitable for drying fuel or heating catalysts required for the chemical conversion of carbon dioxide (CO2). In existing cement clinker manufacturing methods, the extraction of waste heat from the cooler requires no additional thermal compensation.

[0009] The heat energy remaining in the exhaust gas of the rotary kiln after the preheating of the raw materials can be directly utilized by extracting waste heat from the heated exhaust gas separated by a cyclone separator from the first fluidized bed reactor, which acts as a preheater. This is done through a heat exchanger connected to a gas pipeline for discharging the exhaust gas from the first fluidized bed reactor.

[0010] In order to utilize more waste heat from the process of manufacturing cement clinker, waste heat can be extracted from the heated waste gas separated by a cyclone separator from the fluidized bed reactor that functions as a calciner, and the heat exchanger is connected to a gas pipeline for discharging waste gas from a second fluidized bed reactor.

[0011] This method generates more waste heat by introducing another fluidized bed reactor, which also functions as a calciner. This third fluidized bed reactor is connected in the gas flow direction after the second fluidized bed reactor, which also functions as a calciner. Waste heat can then be extracted from the heated waste gas separated by a cyclone separator from the fluidized bed reactor, which functions as a calciner, via a heat exchanger connected to a gas pipeline for discharging waste gas from the second fluidized bed reactor. Attached Figure Description

[0012] The invention is further illustrated with reference to the following figures. In the figures:

[0013] Figure 1 The apparatus for carrying out the method according to the invention is shown in the first design.

[0014] Figure 2 The second design shows the apparatus for implementing the method according to the invention.

[0015] Figure 3 A flowchart of the method according to the invention in the first design scheme is shown.

[0016] Figure 4 A flowchart illustrating the method according to the invention in the second design scheme is shown. Detailed Implementation

[0017] Figure 1A sketch illustrates an apparatus 100 for carrying out the method according to the invention in a first design. This apparatus 100 is preferably designed for producing cement clinker 110 from raw meal 120, but unlike known apparatus, it should generate as much waste heat as possible. Like other known apparatus, this apparatus 100 has at least one rotary kiln 130 for sintering deacidified raw meal 121 into cement clinker 110. The rotary kiln is fueled by a burner, which itself is supplied with primary fuel 200 and primary air 202. In the material flow direction, at least one clinker cooler 140 for cooling the cement clinker 110 is connected after the rotary kiln 130, wherein the clinker cooler 140 shown here has a tertiary air conduit 150 for removing cooling air 147, which is heated in the cooler head housing 149 of the clinker cooler 140, as tertiary air 151. Atmospheric cooling air 147 is blown into the clinker cooler 140 and flows below the cement clinker 110, cooling the hot clinker 110, which has a temperature of approximately 1400°C when discharged from the rotary kiln 130. The heated cooling air 147 experiences a temperature of approximately 1250°C near the head of the rotary kiln, i.e., near the portion of the rotary kiln 130 that protrudes into the cooler 140. Part of the hot cooling air 151 generated in the cooler head housing 149 is further guided into the device 100 via a tertiary air duct 150, which is used to recover heat contained in the hot cooling air. Here, heat originally intended for recovery can be removed from the tertiary air 150 as waste heat Q via a heat exchanger 155. Another portion of the hot cooling air generated there is introduced into the rotary kiln 130 as secondary air 203. The cooling air 147, flowing further away from the head of the rotary kiln, contacts the already cooled cement clinker 110 and is subjected only to the lower temperature of the cement clinker 110 located there. At the end of the clinker cooler 140, the heated cooling air only reaches a temperature between 200°C and 300°C.

[0018] In the device 100, in a gas flow direction largely opposite to the material flow direction, a first fluidized bed reactor 160 is connected as a heat exchanger after the rotary kiln 130, in which raw material 120 is preheated into hot material 122 by the hot exhaust gas from the rotary kiln 130. A first cyclone separator 161 for separating the hot material 122 follows the fluidized bed reactor 160 in the gas flow direction. The cyclone separator 161 separates the hot material 122 from the now cooled exhaust gas from the rotary kiln 130. A first hot material conduit 163 leads the hot material 122 into a second fluidized bed reactor 170, which functions as a calciner. This second fluidized bed reactor is itself connected to and supplied with tertiary air 151 by the tertiary air conduit 150. Feed line 179 introduces deacidified raw meal 121 from second fluidized bed reactor 170, which functions as a calciner, into rotary kiln 130, wherein the deacidified raw meal 121 is separated from the process gas in fluidized bed reactor 170 by cyclone separator 177.

[0019] The device 100 contains multiple locations where heat energy can be extracted from waste gas or process gas. The extracted heat energy, which is lacking in the process of producing cement clinker, can then be compensated for by adding more fuel to other equipment. The first location capable of extracting a large amount of waste heat Q is the gas line 168. It draws waste gas from the aforementioned cyclone separator 161, carrying valuable waste heat extracted by a heat exchanger 165 connected to this gas line 168. A dot is shown above the waste heat Q in the figure, indicating the presence of heat flow. To remove the waste gas from the cyclone separator 161, a compressor 166 is installed downstream of the heat exchanger 165. This compressor supports the gas flow from the rotary kiln 130 to the heat exchanger 165 by removing cooled waste gas 169 carrying carbon dioxide (CO2).

[0020] The second fluidized bed reactor 170, functioning as a calciner, is designed for a residence time of 4 to 8 seconds, and thus typically has a longer residence time than known calciners. This longer residence time facilitates safer and more reliable ignition and burnout of the secondary fuel 201 supplied to the fluidized bed reactor 170 via the fuel inlet 171. The flammability of the secondary fuel 201 is somewhat reduced due to the supply of cooled tertiary air 150 to the fluidized bed reactor 170. Nevertheless, for ignition, the secondary fuel is fed into the fluidized bed reactor, which functions as a calciner, along with the hot feed 122, which provides the necessary ignition energy. The fluidized bed reactor 170, which functions as a calciner, is introduced not only with the hot feed 122 from the first fluidized bed reactor 160, which functions as a heat exchanger, but also with cold raw feed supplied to the fluidized bed reactor via the raw feed inlet 172. By supplying cold raw feed, the temperature in the fluidized bed reactor 170 can be controlled. Hot feedstock 122 is separated by cyclone separator 177. The hot feedstock is calcined into deacidified raw feedstock 121 in the fluidized bed reactor 170, and as previously described, the hot feedstock is guided to the rotary kiln through feed line 179. Waste gas 189 generated in the fluidized bed reactor 170 and separated by cyclone separator 177 exits the equipment 100 through gas line 188. However, before leaving the equipment 100 as cooled waste gas 189, waste heat Q is extracted from the waste gas 189 in the gas line 188 via heat exchanger 185.

[0021] The exhaust gas from the second fluidized bed reactor 170, which functions as a calciner, passes through the combustion chamber 175 to ensure safe and reliable combustion of the fuel. The feed / gas suspension generated in the fluidized bed reactor 170 then enters the cyclone separator 177 via a descending branch line 176.

[0022] Figure 2 A second design embodiment is shown, comprising a device 200 for implementing the method according to the invention. This device is related to… Figure 1The device 100 differs from the one described above in that it includes an additional third fluidized bed reactor 180. In the gas flow direction, this third fluidized bed reactor 180 follows the second fluidized bed reactor 170, which functions as a calciner. This third fluidized bed reactor has a fuel feed 181 for secondary fuel 201 and a raw material feed 182 for raw material 120. This third fluidized bed reactor 180 also functions as a calciner, wherein feed line 183 guides the deacidified raw material 121, separated by a cyclone separator 187, from the third fluidized bed reactor 180 into the rotary kiln 130. Exhaust gas from the second fluidized bed reactor 170, which functions as a calciner, is introduced into the third fluidized bed reactor 180, which also functions as a calciner, with an oxygen content of 10%–15%. There, additional secondary fuel 201 is fed along with a portion of the raw material 120. The raw material 120 is also used for temperature control in this fluidized bed reactor 180. After the secondary fuel 201 is ignited, the remaining raw material 120 is added, heated, and calcined. This third fluidized bed reactor, which also functions as a calciner, is designed for a residence time of 4 to 8 seconds and has a combustion chamber 185 in its deflection section to support complete combustion of the secondary fuel 201. For the remaining components of the apparatus 200, please refer to [reference needed]. Figure 1 Explanation.

[0023] Figure 3 A flowchart of the method according to the invention in the first design embodiment is shown. The method for producing cement clinker 110 from raw meal 120 includes the following steps: starting with the preparation of raw meal, a mixture of silicate and carbonate rocks; preheating the raw meal 120 10 to make it hot feed 122; then separating the hot feed 122 20 in a cyclone separator 161; and introducing the hot feed 122 into a fluidized bed reactor 170 through a hot feed line 163. After this, the hot feed 122 is calcined 30 in the fluidized bed reactor 170, which functions as a calciner, to become deacidified raw meal 121. After deacidification, the deacidified raw meal 121 is separated 40 in a cyclone separator 177 following the fluidized bed reactor 170 in the gas flow direction. From there, the separated deacidified raw meal 121 is sintered 50 in a rotary kiln 130 to become cement clinker 110.

[0024] According to the concept of the present invention, a method is defined as follows: the raw material 120 is preheated 10 in a fluidized bed reactor 160, which serves as a first fluidized bed reactor, to become a hot material 122, and the exhaust gas from the rotary kiln 130 is applied to the first fluidized bed reactor 160. Here, this method differs from known methods for manufacturing cement clinker 110 in that the exhaust gas from the rotary kiln 130 is not used for calcination but for the preheating 10, and the preheating occurs in the fluidized bed reactor 160 to withstand the high exhaust gas temperature of the rotary kiln 130.

[0025] Following the sintering, a known method step may be performed to cool the cement clinker 110 in a clinker cooler 140 following the rotary kiln 130 in the material flow direction, and then heated cooling air, which serves as tertiary air 151, is introduced from the cooler head shell 149 of the clinker cooler 140 into the second fluidized bed reactor 170 via a tertiary air line 150.

[0026] In order to extract waste heat from this method, there are four specific locations that are suitable.

[0027] The first separation point for waste heat Q is located in the gas path after separator 161 of the first fluidized bed reactor 160 used for preheating the raw material 120, in method step 20 "Separation".

[0028] The second separation location for waste heat Q is located in the gas path after separator 177 of the second fluidized bed reactor 170 for calcining raw / hot feed, in method step 40 "Separation".

[0029] The third removal location for waste heat Q is located in the gas path after cooling in the clinker cooler 140, in method step 60 "Cooling".

[0030] The fourth extraction point for waste heat Q is located in the gas path of the tertiary air 150, i.e., in the tertiary air pipeline, in method step 65 "Import".

[0031] The waste heat Q that can be extracted at the aforementioned extraction locations can be used to operate another method for separating carbon dioxide (CO2), the generation of which is unavoidable in the manufacture of cement clinker 110.

[0032] at last, Figure 4 A flowchart illustrating the method according to the invention in the second design scheme is shown. According to this flowchart, this method is similar to that according to... Figure 3The difference in the flowchart method lies in another method step, calcination 70. This method step is placed after the first calcination step 30 and the separation step 40. This second calcination step increases the capacity of the second fluidized bed reactor 170, which functions as a calciner. This is because the second fluidized bed reactor 170, which functions as a calciner, operates at a reduced temperature to supply it with tertiary air.

[0033] List of reference numerals

[0034] 10. Preheating

[0035] 20 Separation

[0036] 25 Extraction

[0037] 30 calcination

[0038] 40 Separation

[0039] 45 Extraction

[0040] 50 Sintering

[0041] 60 Cooling

[0042] 65 Import

[0043] 66 Extraction

[0044] 67 Extraction

[0045] 70 calcination

[0046] 75 Extraction

[0047] 100 devices

[0048] 110 Cement Clinker

[0049] 120 raw materials

[0050] 121 Deacidified raw meal

[0051] 122 Hot Materials

[0052] 130 rotary kiln

[0053] 131 Feeding Room

[0054] 140 Clinker Cooler

[0055] 145 heat exchanger

[0056] 146 Expel air

[0057] 147 Cooling Air

[0058] 148 Gas Piping

[0059] 149 Cooler head housing

[0060] 150 tertiary air piping

[0061] 151 Third Air

[0062] 155 heat exchanger

[0063] 160 First fluidized bed reactor

[0064] 161 Cyclone Separator

[0065] 162 Raw Material Supply Section

[0066] 163 Hot material piping

[0067] 165 heat exchanger

[0068] 166 compressor

[0069] 168 Gas Piping

[0070] 169 Exhaust Gas

[0071] 170 Second fluidized bed reactor

[0072] 171 Fuel supply department

[0073] 172 Raw Material Supply Department

[0074] 175 Combustion Chamber

[0075] 176 Downward branch

[0076] 177 Cyclone Separator

[0077] 179 Material Pipeline

[0078] 180 Third-stage fluidized bed reactor

[0079] 181 Fuel supply department

[0080] 182 Raw Material Supply Department

[0081] 183 Material Pipeline

[0082] 185 heat exchanger

[0083] 186 Downward branch

[0084] 187 Cyclone Separator

[0085] 188 Gas Pipeline

[0086] 189 Exhaust Gas

[0087] 186 compressor

[0088] 200 fuel per charge

[0089] 201 Secondary fuel

[0090] 202 First-time air

[0091] 203 Secondary Air

[0092] Q Waste heat

[0093] B fuel

Claims

1. A method for producing cement clinker (110) from raw meal (120), comprising the following steps: - The raw material (120) is preheated (10) to become hot material (122). - The hot material (122) is separated (20) in a cyclone separator (161) and introduced into the fluidized bed reactor (170) through a hot material pipeline (163). - In the fluidized bed reactor (170) that serves as a calciner, the hot feed (122) is calcined (30) to become a deacidified raw feed (121). - The deacidified raw material (121) is separated (40) in a cyclone separator (177) following the fluidized bed reactor (170) as a calciner in the direction of gas flow. - The separated deacidified raw meal (121) is sintered (50) in a rotary kiln (130) to become cement clinker (110). Its features are, - The raw material (120) is preheated (10) in the fluidized bed reactor (160), which serves as the first fluidized bed reactor, to make it a hot material (122). - The exhaust gas from the rotary kiln (130) is applied to the first fluidized bed reactor (160) (55).

2. The method according to claim 1, Its features are, - The cement clinker (110) is cooled (60) in a clinker cooler (140) which is connected to the rotary kiln (130) in the material flow direction. - The heated cooling air is introduced as tertiary air (151) from the cooler head shell (149) of the clinker cooler (140) through the tertiary air pipe (150) into the second fluidized bed reactor (65).

3. The method according to claim 2, Its features are, Waste heat (Q) is extracted (66) from the tertiary air (151) through a heat exchanger (155) connected to the tertiary air line (150).

4. The method according to claim 2 or 3, Its features are, Waste heat (Q) is extracted (67) from heated cooling air (147) which is exhaust air (146) via a heat exchanger (145), wherein the heat exchanger is connected to a gas line (148) for discharging exhaust air (146) from the cooler (140).

5. The method according to any one of claims 2 to 4, Its features are, - Waste heat (Q) is extracted (25) from the heated waste gas (169) separated by cyclone separator (161) from the first fluidized bed reactor (160) via a heat exchanger (165), wherein the heat exchanger is connected to a gas line (168) for discharging the waste gas (169) from the first fluidized bed reactor (160).

6. The method according to any one of claims 2 to 5, Its features are, - Waste heat (Q) is extracted (45) from heated waste gas (189) separated by cyclone separator (177) from the fluidized bed reactor (170) which functions as a calciner, via a heat exchanger (185), wherein the heat exchanger is connected to a gas line (188) for discharging the waste gas (189) from the second fluidized bed reactor (170).

7. The method according to any one of claims 1 to 5, Its features are, - In the gas flow direction, a third fluidized bed reactor (180), which acts as another calciner, is connected after the fluidized bed reactor (170), which functions as a calciner. - In the third fluidized bed reactor (180), the additional raw material (120) is calcined (70) to become deacidified raw material (121). - The raw material (121) that has been deacidified in the third fluidized bed reactor (180) is separated (80) in a cyclone separator (187). - The separated deacidified raw material (121) from the cyclone separator (187) is introduced into the rotary kiln (130).

8. The method according to claim 7, Its features are, - Waste heat (Q) is extracted (85) from the heated waste gas (189) separated by a cyclone separator (187) from the third fluidized bed reactor (180) via a heat exchanger (185), wherein the heat exchanger is connected to a gas line (188) for discharging the waste gas (189) from the third fluidized bed reactor (180).

9. The method according to any one of claims 3 to 6 and claim 8, Its features are, The extracted waste heat (Q) is applied to run another method for separating and / or storing carbon dioxide (CO2) from the waste gas generated in the method according to any one of claims 1 to 8.

10. An apparatus (100) for producing cement clinker (110) from raw materials (120), comprising, according to the method of claims 1 to 9: - At least one rotary kiln (130) for sintering deacidified raw meal (121) into cement clinker (110). - At least one clinker cooler (140) for cooling the cement clinker (110), wherein, The clinker cooler (140) is connected downstream of the rotary kiln (130) in the material flow direction. - At least one tertiary air line (150) for taking away cooling air (147) heated in the cooler head housing (149) of the clinker cooler (140) as tertiary air (151). Its features are, A first fluidized bed reactor (160), serving as a heat exchanger, is connected after the rotary kiln (130) in the gas flow direction. In this first fluidized bed reactor, raw material (120) is preheated to become hot material (122), while a first cyclone separator (161) for separating the hot material (122) follows the first fluidized bed reactor in the gas flow direction. The first hot material pipeline (163) introduces the hot material (122) into the second fluidized bed reactor (170), which serves as a calciner. This second fluidized bed reactor is connected to the tertiary air pipeline (150) and is supplied with tertiary air (151) by the tertiary air pipeline. The feed line (179) introduces the deacidified raw meal (121) from the second fluidized bed reactor (170), which functions as a calciner, into the rotary kiln (130).

11. The device according to claim 10, Its features are, The second fluidized bed reactor (170), which functions as a calciner, has a fuel inlet (171) for secondary fuel (201).

12. The device according to claim 10 or 11, Its features are, The second fluidized bed reactor (170), which functions as a calciner, has a raw material feed section (172).

13. The device according to any one of claims 10 to 12, Its features are, The third fluidized bed reactor (180) follows the second fluidized bed reactor (170), which functions as a calciner, in the gas flow direction. The third fluidized bed reactor has a fuel feed section (181) for secondary fuel (201) and a raw material feed section (182) for raw material (120), wherein a feed line (183) introduces the deacidified raw material (121) from the third fluidized bed reactor (180) into the rotary kiln (130).

14. The device according to any one of claims 10 to 13, Its features are, Each heat exchanger (145, 165) is connected in the gas path of the clinker cooler (140) and / or the first fluidized bed reactor (160) in the gas flow direction in the gas line (148, 168), through which heat (Q) for operating another device for separating carbon dioxide (CO2) is separated.

15. The device according to any one of claims 10 to 14, Its features are, A heat exchanger (155) is connected to the tertiary air line (150), through which heat (Q) for operating another device for separating carbon dioxide (CO2) is separated.

16. The device according to claim 13, Its features are, A heat exchanger (185) is connected in the gas path of the third fluidized bed reactor (180) in the gas flow direction in the gas pipeline (188), through which heat (Q) for operating another device for separating carbon dioxide (CO2) is separated.

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