Plant for production of cement with thermal energy extraction

Abstract

The invention relates to a plant (100, 200, 300, 400) for producing cement clinker from raw meal, comprising at least one heat exchanger (110, 210, 310, 410) located downstream in the gas flow direction, and at least one device (120, 220, 320, 420) following in the material flow direction for preheating, calcining and sintering raw meal, wherein this device can consist of individual and successive devices, wherein the at least one device (120, 220, 320, 420) for preheating, calcining and sintering raw meal is connected on the primary side to the at least one heat exchanger (110, 210, 310, 410) located downstream in the gas flow direction and is exposed to exhaust gas. According to the invention, the at least one heat exchanger (110, 210, 310, 410) located downstream in the gas flow direction is connected on the secondary side to a downstream plant for separating and / or storing carbon dioxide (CO2) from the exhaust gas. This plant configuration, without a raw meal preheater, allows the plant to be operated with an excess of fuel, so that the exhaust gas from the plant has enough heat to operate a coupled process for the separation and / or storage of carbon dioxide.

Description

[0001] Plant for the production of cement with thermal energy extraction

[0002] The invention relates to a plant for producing cement clinker from raw meal, comprising at least one heat exchanger located downstream in the gas flow direction and at least one device for preheating, calcining and sintering raw meal following in the material flow direction, wherein this device can also consist of individual and successive individual devices, wherein the at least one device for preheating, calcining and sintering raw meal is connected on the primary side to the at least one heat exchanger located downstream in the gas flow direction and is supplied with exhaust gas.

[0003] To produce cement clinker from raw meal made from ground, calcareous, and silicate-containing rock, the raw meal undergoes heat treatment in several sequential stages. In a first step, the raw meal is preheated using waste heat from the subsequent thermal treatment steps. The preheated raw meal is then deacidified or calcined to formally expel carbon dioxide (CO2) from the carbonate (CO3) of the calcareous raw meal. Finally, the deacidified or calcined raw meal is sintered in a rotary kiln to form cement clinker in a solid-state chemical reaction. Sintering is followed by rapid cooling to prevent desired clinker phases in the cement clinker from transforming into other phases during cooling. The entire production process is subject to continuous optimization to keep waste heat in the process.The desirable goal is to supply only as much heat to the entire production process as corresponds to the enthalpy of formation of cement clinker from raw meal. The motivation behind this process optimization, carried out over the past decades, was to consistently minimize the heat demand generated from economically expensive fuels. A later optimization of the production process involves denitrification of exhaust gases, i.e., the avoidance of nitrogen oxides (NOx) in the exhaust gases, which are recognized as the cause of acid rain observed worldwide. A further optimization step, currently the subject of innovation in the cement clinker production process, is the avoidance of carbon dioxide (CO2) emissions, which, as mentioned above, is driven out of the raw meal.Together with carbon dioxide (CO2) from the combustion of fossil fuels, the emission of carbon dioxide (CO2) from cement clinker production represents a large portion of anthropogenic carbon dioxide emissions. Carbon dioxide (CO2) is considered to be the cause of the currently observable global warming. The capture of carbon dioxide (CO2) from industrial exhaust gases and its subsequent storage are highly endothermic processes. This means that both capture and storage, be it compression and storage in underground aquifers or the chemical conversion of carbon dioxide (CO2) to non-gaseous substances in coupled processes, consume energy. If this energy is captured from further combustion processes in a subsequent process to generate heat or electricity, this immediately results in further emissions of carbon dioxide (CO2), and this carbon dioxide (CO2) should also be captured.Since current processes and the corresponding plants for producing cement clinker are largely energy-optimized, the generation of heat or electricity from such a plant is not possible to the required extent. Existing plants and processes for producing cement clinker generate more carbon dioxide emissions than can be captured with the available waste heat for operating a so-called "capture process," i.e., a downstream capture process to prevent carbon dioxide (CO2) emissions. An obvious solution for preserving heat as energy for the capture process would be to increase the fuel input in a known cement clinker production plant and the corresponding process, thus generating more waste heat. However, this additional fuel input would raise temperatures within the plant, significantly altering the plant's energy balance.As a result, the previously implemented denitrification optimization would be reversed, and the production process would become unbalanced at many points within the plant. The resulting cement clinker would, as expected, be of lower quality because the composition of the desired clinker phases would change with the increased energy input, and the quality of denitrification would be reduced.

[0004] The object of the invention is therefore to propose a plant for the production of cement clinker and a corresponding process whose energy balance allows the available waste heat to be used to operate a downstream capture process for the separation and storage of carbon dioxide (CO2) from the exhaust gases of the plant.

[0005] The object of the invention is achieved by a system according to claim 1 and a corresponding method according to claim 6. Further advantageous embodiments of the system are specified in the subclaims to claim 1. Further advantageous embodiments of the method are specified in the subclaims to claim 6.

[0006] The plant presented here and the corresponding process are based on the elimination of separate preheating of the raw meal in a cement clinker production plant. In previously known cement clinker production plants, the heat present in the exhaust gas from a calcining and sintering device is transferred to cold raw meal in a separate device, namely the preheater. As a result, the exhaust gas cools significantly, and the raw meal reaches a temperature slightly below the dissociation temperature of lime (CaCO3).This energy recovery allows the calcining and sintering device, whether it involves separate plant components such as a circulating fluidized-bed reactor, a tubular reactor, or a calciner and a rotary kiln, or a single plant component such as a long rotary kiln or a pot calciner, to be operated with far less fuel because the raw meal enters the reactor(s) already preheated. The aim of the present invention is not to keep the exhaust gas temperature low, as is the case in the prior art, but to raise it to a level that allows the heat contained in the exhaust gas to be used to operate a coupled system for the capture and / or storage of carbon dioxide (CO2).The aim of the invention is not to operate the plant and the corresponding process in an energy-efficient manner with respect to the amount of cement clinker emitted, but rather to operate it in an energy-efficient manner with respect to the amount of cement clinker emitted and the capture of carbon dioxide (CO2). The concept of the invention does not preclude the possibility of compressing the carbon dioxide (CO2) for storage using the recovered waste heat or chemically converting it into other substances. Methanol is a possible conversion, but chemical conversion to solids is also possible.

[0007] According to the concept of the invention, it is therefore provided that the at least one heat exchanger located downstream in the direction of gas flow is connected on the secondary side to a downstream system for separating and / or storing carbon dioxide (CO2) from the exhaust gas. In this case, the type of coupled process used is initially of secondary importance. For example, possible processes include scrubbing the exhaust gas with an amine scrubber and subsequent storage of the separated carbon dioxide (CO2), or producing methanol (CH3OH) from carbon dioxide (CO2) and hydrogen (H2) obtained from the electrolysis of water (H2O), wherein the electrolysis is operated using electrical current generated by steam. The aforementioned steam was generated using the heat in the exhaust gas from the plant for producing cement clinker.According to the concept presented here, the term "storage" therefore includes storage in order to leave it at the storage location or storage in the form of chemical conversion to another substance and optional use of the converted substance for other purposes.

[0008] According to the idea of ​​the invention, it can be provided that by regulating the fuel supply to at least one device for preheating, calcining and sintering, so much heat is generated by burning predominantly secondary fuels that the separation and / or storage of carbon dioxide (CO2) consumes precisely this excess heat without any residual energy remaining.

[0009] The special feature of the invention presented here is that the increased fuel consumption in the production of cement clinker, particularly when burning low-calorie or even low-value fuels, can be achieved with comparatively low emissions and at low cost. Examples of low-calorie or even low-value fuels that can be considered are processed industrial waste and / or household waste, scrap tires, solvent waste, or processed biomass. If the energy for capturing and / or storing the carbon dioxide (CO2) generated during the production of cement clinker were to be generated separately, the technology for keeping the air clean would be economically very complex if the energy were also to be generated using low-calorie or low-value fuels. Cement clinker production plants burn these in the presence of raw meal.The raw meal has a strong catalytic effect on the decomposition of nitrogen oxides (NOx), volatile organic compounds (VOCs), and hazardous air pollutants (HAPs). It is even possible to use fuels that tend to form furans and dioxins upon combustion. Such fuels can include polyvinyl chloride (PVC) waste, halogenated solvents, and other halogenated hydrocarbons. Typical cement clinker production plants usually already have technologies for denitrification and the prevention of dioxin and furan emissions. Non-volatile combustion residues, including heavy metals and pollutant-containing solid combustion residues, are adsorbed by the cement clinker and incorporated into the cement clinker, or the cement clinker encapsulates these pollutants, preventing them from being emitted into the environment with the exhaust gases.

[0010] While cement clinker production plants have sophisticated technologies for preventing emissions, in order to safely control and neutralize the increase in emissions caused by the excess fuel used, it has proven advantageous to install a reactor for the regenerative thermal oxidation (RTO) of pollutants between the heat exchanger, which is connected on the secondary side to the downstream plant for the capture and / or storage of carbon dioxide (CO2), and between the heat exchanger and the device for preheating, calcining, and sintering raw meal. This reactor oxidizes volatile organic compounds and hazardous air pollutants.To operate the reactor for regenerative thermal oxidation of pollutants, it has proven advantageous to regulate the fuel consumption in the cement clinker production plant according to the temperature of the exhaust gas at the point where the exhaust gas flows into the reactor for regenerative thermal oxidation of pollutants. Here, the temperature should be between 800°C and 900°C, preferably around 850°C with a tolerance of 20°C.

[0011] The use of non-preheated raw meal generally renders the use of a calciner of the type used, which acts as an entrained-flow reactor between a conventional raw meal preheater and a rotary kiln, unsuitable, because calciners are designed to accommodate preheated raw meal. The residence time of the cold raw meal in such calciners is insufficient to heat the raw meal and then deacidify it (calcination). In this case, it has proven advantageous to use a tubular reactor, a longer rotary kiln, or a circulating fluidized-bed reactor as the device for preheating, calcination, and sintering. In a tubular reactor, the residence time of the raw meal is significantly longer than in an entrained-flow reactor as a calciner, as commonly used today. Preheating, calcination, and sintering can all take place in a rotary kiln.Very early plants for the production of cement clinker used a longer rotary kiln to carry out the three steps of preheating, calcining, and sintering in one single process. The disadvantage of the long rotary kiln is that the exhaust gas temperature is relatively high, resulting in thermal energy loss. However, in the plant and process presented here, the goal is precisely to keep the exhaust gas temperature high in order to utilize this heat in a combined process.

[0012] Depending on the operating mode of the rotary kiln, it is advantageous to have a tubular reactor downstream of the rotary kiln in terms of gas flow. When operating with a superstoichiometric air supply (lambda > 1 ), the exhaust gas from the rotary kiln can be fed directly into a reactor for the regenerative thermal oxidation of pollutants. However, if the rotary kiln is operated with a substoichiometric air supply (lambda < 1 ), it is recommended that the exhaust gas from the rotary kiln be fed into a tubular reactor as lean gas to convert any fuel or pyrolysis gases still present in the gas space.

[0013] As mentioned above, it is possible for the secondary-side system for capturing and / or storing carbon dioxide (CO2) to generate electrical power with a steam generator for generating electrical energy, which supplies a device for electrolyzing water. The hydrogen (H2) electrolyzing device is connected on the hydrogen side to a reformer in which the exhaust gas, cooled in the heat exchanger and containing carbon dioxide (CO2), is converted into methanol (CH3OH). The invention is explained in more detail with reference to the following figures. It shows:

[0014] Fig. 1 shows a plant according to the invention for producing cement clinker in a first embodiment,

[0015] Fig. 2 shows a plant according to the invention for producing cement clinker in a second embodiment,

[0016] Fig. 3 shows a plant according to the invention for producing cement clinker in a third embodiment,

[0017] Fig. 4 a plant according to the invention for the production of cement clinker In a fourth embodiment,

[0018] Fig. 5 shows a plant according to the invention for producing cement clinker in a fifth embodiment.

[0019] Fig. 6 shows a plant according to the invention for producing cement clinker in a sixth embodiment.

[0020] Figure 1 shows a first embodiment of a plant 100 according to the invention for producing cement clinker. This first embodiment consists, viewed against the gas flow direction, of a heat exchanger 110 for dissipating heat from the exhaust gas of plant 100 to a coupled process for capturing and / or storing carbon dioxide (CO2), an RTO reactor 130 for the regenerative thermal oxidation of volatile organic compounds (VOCs) in the exhaust gas of plant 100 and for converting hazardous air pollutants (HAP). This is followed by a circulating fluidized-bed reactor 140 as a device 120 for preheating, calcining, and sintering the raw meal to produce cement clinker, with all three steps—namely, preheating, calcining, and sintering—being carried out in the circulating fluidized-bed reactor 140. Primary and / or secondary fuel is introduced into this circulating fluidized bed reactor 140, which heats the circulating fluidized bed.The circulating fluidized bed therein can flow in the direction of the exhaust gas flow toward the RTO reactor 130, with solids from the circulating fluidized bed being separated by the cyclone 141 and recirculated back into the circulating fluidized bed reactor 140. Raw meal sintered into cement clinker falls from the circulating fluidized bed reactor 140 down into line 142, where the hot cement clinker passes into the clinker cooler 150 and is rapidly cooled by quenching with atmospheric cooling air. The hot cooling air from the clinker cooler 150 is recirculated to the circulating fluidized bed reactor 140 through a tertiary air line 151. This recovers the heat in the cement clinker and returns it to the process.An optional heat exchanger 111, shown here in the tertiary air line 151, conducts heat from the hot cooling air on the secondary side to a system 1000 for the separation and / or storage of carbon dioxide (CO2), where the heat is used as process heat to support the separation and / or storage of carbon dioxide (CO2). According to the concept of the invention, it can be provided that the fuel / air supply to the circulating fluidized-bed reactor 140 is guided according to the temperature of the exhaust gas upstream of the RTO reactor 130 for regenerative thermal oxidation, specifically such that the temperature there is between 800°C and 900°C, preferably a temperature of 850°C with a tolerance of 20°C.The heat Q present in the exhaust gas of the plant and transferable by a heat exchanger 110 is sufficient for carbon dioxide (CO2) to be removed from the exhaust gas using a plant for separating and / or storing carbon dioxide (CO2) from the exhaust gas, which plant is present in the secondary circuit of the heat exchanger 110. The heat Q extracted from the exhaust gas of the plant 100 is used for separation or storage in a coupled process of the plant 1000 for separating and / or storing carbon dioxide (CO2). The separation and / or storage may also include chemical conversion to other chemical substances, such as methanol production in a reformer. Figure 2 shows a plant 200 according to the invention for producing cement clinker in a second embodiment.This second embodiment consists, viewed against the gas flow direction, of a heat exchanger 210 for dissipating heat from the exhaust gas of plant 200 to a coupled process for capturing and / or storing carbon dioxide (CO2), an RTO reactor 230 for the regenerative thermal oxidation of volatile organic compounds (VOCs) in the exhaust gas of plant 200, and for converting hazardous air pollutants (HAP). This is followed by a dust collector 252, which returns dust from the exhaust gases of the downstream rotary kiln 240 to the rotary kiln inlet chamber 260. Following the dust collector 252 is the rotary kiln 240, a device 220 for preheating, calcining, and sintering the raw meal to produce cement clinker. In the rotary kiln 240, the raw meal is both preheated, calcined, and sintered. After passing through the rotary kiln 240, the sintered cement clinker falls into a clinker cooler 250, where the cement clinker is quenched by atmospheric cooling air.The heated cooling air is passed from the clinker cooler 250 as tertiary air through the tertiary air line 251 into the exhaust gas of the rotary kiln 250. This recovers the heat present in the hot cement clinker and returns it to the process. An optional heat exchanger 211, shown here in the tertiary air line 251, transfers heat from the hot cooling air on the secondary side to a system 1000 for the capture and / or storage of carbon dioxide (CO2), where the heat is used as process heat to support the capture and / or storage of carbon dioxide (CO2). According to the concept of the invention, it can be provided that the fuel / air supply into the rotary kiln 240 is guided according to the temperature of the exhaust gas upstream of the RTO reactor 230 for regenerative thermal oxidation, in such a way that the temperature there is between 800°C and 900°C, preferably a temperature of 850°C with a tolerance of 20°C.The heat Q present in the exhaust gas of the system and transferable by a heat exchanger 210 is sufficient for carbon dioxide (CO2) to be extracted from the exhaust gas using a system for capturing and / or storing carbon dioxide (CO2) from the exhaust gas, which system is present in the secondary circuit of the heat exchanger 3210. The heat Q extracted from the exhaust gas of the system 200 is used in a coupled process of the system 1000 for capturing and / or storing carbon dioxide (CO2) for capture or storage, wherein the capture and / or storage may also include chemical conversion to other chemical substances, such as methanol production in a reformer.

[0021] Figure 3 shows a third embodiment of a plant according to the invention for producing cement clinker. This third embodiment consists, viewed against the gas flow direction, of a heat exchanger 310 for dissipating heat from the exhaust gas of plant 300 to a coupled process for capturing and / or storing carbon dioxide (CO2), an RTO reactor 330 for the regenerative thermal oxidation of volatile organic compounds (VOCs) in the exhaust gas of plant 300 and for converting hazardous air pollutants (HAP). This is followed by a dust collector 352 for passing dust expelled from tubular reactor 340 with the exhaust gas into a clinker cooler 350, past the following tubular reactor 340. The dust collector 352 is followed by a tubular reactor 340 as a device 320 for preheating, calcining and sintering, whereby these three process steps take place in the tubular reactor 340.Compared to a prior art entrained-flow reactor as a calciner, the tubular reactor 340 has the property of having a longer residence time. This residence time is thus sufficient for the raw meal to be preheated, calcined, and sintered. The cement clinker exiting the tubular reactor 340 then falls into a clinker cooler 350, where the hot cement clinker is quenched by atmospheric cooling air. The heated cooling air is fed into the tubular reactor 340 through a tertiary air line 351 to recover the heat present in the hot cement clinker and return it to the process. An optional heat exchanger 311 shown here in the tertiary air line 351 transfers heat from the hot cooling air on the secondary side to a system 1000 for separating and / or storing carbon dioxide (CO2), where the heat is used as process heat to support the separation and / or storage of carbon dioxide (CO2).According to the concept of the invention, it can be provided that the fuel / air supply to the tubular reactor 340 is guided according to the temperature of the exhaust gas upstream of the RTO reactor 330 for regenerative thermal oxidation, in such a way that the temperature there is between 800°C and 900°C, preferably a temperature of 850°C with a tolerance of 20°C. The heat Q present in the exhaust gas of the system and transferable by a heat exchanger 310 is sufficient that carbon dioxide (CO2) can be removed from the exhaust gas using a system for separating and / or storing carbon dioxide (CO2) from the exhaust gas, which system is present in the secondary circuit of the heat exchanger 310.The heat Q extracted from the exhaust gas of the plant 300 is used in a coupled process of the plant 1000 for the capture and / or storage of carbon dioxide (CO2) for capture or storage, wherein the capture and / or storage may also include the chemical conversion to other chemical substances, such as the production of methanol in a reformer.

[0022] Figure 4 shows a fourth embodiment of a plant according to the invention for producing cement clinker. This fourth embodiment consists, viewed against the gas flow direction, of a heat exchanger 410 for dissipating heat from the exhaust gas of plant 400 to a coupled process for capturing and / or storing carbon dioxide (CO2), an RTO reactor 430 for the regenerative thermal oxidation of volatile organic compounds (VOCs) in the exhaust gas of plant 400 and for converting hazardous air pollutants (HAP). The RT reactor 430 is followed by a combination of a circulating fluidized bed reactor 440 and a tubular reactor 445. Together, these two act as a device for preheating, calcining, and sintering 420. The raw meal is fed into the circulating fluidized bed reactor 440, where it is preheated and calcined.During discharge, a portion of the fluidized bed in the circulating fluidized-bed reactor 440 is recirculated via the cyclone 441 back into the circulating fluidized-bed reactor 440. Preheated and calcined raw meal then falls into a subsequent tube reactor 445 for the sintering process. The raw meal sintered into cement clinker then falls into a clinker cooler 450, where the still-hot cement clinker is quenched by rapid cooling with atmospheric air. The cooling air, which is heated in the process, is fed back into the circulating fluidized-bed reactor 440 as tertiary air via a tertiary air line 451 to recover heat from the hot cement clinker and return it to the process.An optional heat exchanger 411, shown here in the tertiary air line 451, conducts heat from the hot cooling air on the secondary side to a system 1000 for the separation and / or storage of carbon dioxide (CO2), where the heat is used as process heat to support the separation and / or storage of carbon dioxide (CO2). At the end of the clinker cooler 450, the now still moderately hot cement clinker leaves the system. According to the concept of the invention, it can be provided that the fuel / air supply is directed into the circulating fluidized bed reactor 440 and into the tubular reactor 445 according to the temperature of the exhaust gas upstream of the RTO reactor 430 for regenerative thermal oxidation, in such a way that the temperature there is between 800°C and 900°C, preferably a temperature of 850°C with a tolerance of 20°C.The heat Q present in the exhaust gas of the system and transferable by a heat exchanger 410 is sufficient for carbon dioxide (CO2) to be removed from the exhaust gas using a system for capturing and / or storing carbon dioxide (CO2) from the exhaust gas, which is present in the secondary circuit of the heat exchanger 410. The heat Q extracted from the exhaust gas of the system 400 is used in a coupled process of the system 1000 for capturing and / or storing carbon dioxide (CO2) for capture or storage, wherein the capture and / or storage may also include chemical conversion to other chemical substances, such as methanol production in a reformer.

[0023] Figure 5 shows a fifth embodiment of a plant according to the invention for producing cement clinker. This fifth embodiment consists, viewed against the gas flow direction, of a heat exchanger 510 for dissipating heat from the exhaust gas of plant 500 to a coupled process for capturing and / or storing carbon dioxide (CO2), an RTO reactor 530 for the regenerative thermal oxidation of volatile organic compounds (VOCs) in the exhaust gas of plant 500 and for converting hazardous air pollutants (HAP). The RT reactor 530 is followed by a combination of a circulating fluidized bed reactor 540 and a rotary kiln 545. Together, these two act as a device for preheating, calcining, and sintering 520. The raw meal is fed into the circulating fluidized bed reactor 540, where it is preheated and calcined.During discharge, a portion of the fluidized bed in the circulating fluidized bed reactor 540 is recirculated via the cyclone 541 back into the circulating fluidized bed reactor 540. Preheated and calcined raw meal then falls into a subsequent rotary kiln 545 for the sintering process. The raw meal sintered into cement clinker then falls into a clinker cooler 550, where the still-hot cement clinker is quenched by rapid cooling with atmospheric air. The cooling air, which is heated in the process, is fed back into the circulating fluidized bed reactor 540 as tertiary air via a tertiary air line 551 to recover heat from the hot cement clinker and return it to the process.An optional heat exchanger 511, shown here in the tertiary air line 551, conducts heat from the hot cooling air on the secondary side to a system 1000 for the separation and / or storage of carbon dioxide (CO2), where the heat is used as process heat to support the separation and / or storage of carbon dioxide (CO2). At the end of the clinker cooler 550, the now still moderately hot cement clinker leaves the system. According to the concept of the invention, it can be provided that the fuel / air supply to the circulating fluidized bed reactor 540 and to the rotary kiln 545 is guided according to the temperature of the exhaust gas upstream of the RTO reactor 530 for regenerative thermal oxidation, specifically such that the temperature there is between 800°C and 900°C, preferably a temperature of 850°C with a tolerance of 20°C.The heat Q present in the exhaust gas of the system and transferable by a heat exchanger 510 is sufficient for carbon dioxide (CO2) to be removed from the exhaust gas using a system for capturing and / or storing carbon dioxide (CO2) from the exhaust gas, which is present in the secondary circuit of the heat exchanger 410. The heat Q extracted from the exhaust gas of the system 500 is used in a coupled process of the system 1000 for capturing and / or storing carbon dioxide (CO2) for capture or storage, wherein the capture and / or storage may also include chemical conversion to other chemical substances, such as methanol production in a reformer.

[0024] Figure 6 shows a sixth embodiment of a plant 600 according to the invention for producing cement clinker. This sixth embodiment consists, viewed against the gas flow direction, of a heat exchanger 610 for dissipating heat from the exhaust gas of plant 600 to a coupled process for capturing and / or storing carbon dioxide (CO2), an RTO reactor 630 for the regenerative thermal oxidation of volatile organic compounds (VOCs) in the exhaust gas of plant 600, and for converting hazardous air pollutants (HAP). This is followed by a tubular reactor 640. In this tubular reactor 640, the hot raw meal is preheated and calcined. Following the tubular reactor 640 is a rotary kiln 645, in which the calcined raw meal is sintered. Both units, the tube reactor 640 and the rotary kiln 640, represent the device 620 for preheating, calcining and sintering.From the tubular reactor 640, the raw meal is fed directly into the rotary kiln inlet chamber 260, where dust from the air flowing out of the tubular reactor 640 is also fed back into the rotary kiln 645. In the rotary kiln 645, the previously calcined raw meal is sintered into cement clinker. After passing through the rotary kiln 645, the sintered cement clinker falls into the clinker cooler 650, where the cement clinker is quenched with atmospheric cooling air. Heated cooling air from the clinker cooler 650 is fed as tertiary air through the tertiary air line 6 upstream of the tubular reactor 640 to recover the heat from the hot cement clinker into the process.An optional heat exchanger 611, shown here in the tertiary air line 651, conducts heat from the hot cooling air on the secondary side to a system 1000 for the separation and / or storage of carbon dioxide (CO2), where the heat is used as process heat to support the separation and / or storage of carbon dioxide (CO2). According to the concept of the invention, it can be provided that the fuel / air supply to the tube reactor 640 and / or the rotary kiln 645 is guided according to the temperature of the exhaust gas upstream of the RTO reactor 630 for regenerative thermal oxidation, specifically such that the temperature there is between 800°C and 900°C, preferably a temperature of 850°C with a tolerance of 20°C.The heat Q present in the exhaust gas of the system and transferable by a heat exchanger 610 is sufficient for carbon dioxide (CO2) to be removed from the exhaust gas using a system for separating and / or storing carbon dioxide (CO2) from the exhaust gas, which system is present in the secondary circuit of the heat exchanger 110. The heat Q extracted from the exhaust gas of the system 600 is used in a coupled process of the system 1000 for separating and / or storing carbon dioxide (CO2) for separation or storage, wherein the separation and / or storage may also include chemical conversion to other chemical substances, such as methanol production in a reformer. LIST OF REFERENCE SYMBOLS E.

[0025] Appendix 300 Appendix

[0026] Heat exchanger 310 Heat exchanger

[0027] Heat exchanger 311 Heat exchanger

[0028] Device for preheating, calcining and sintering, calcining and sintering

[0029] Reactor for regenerative 330 Reactor for regenerative thermal oxidation thermal oxidation circulating fluidized bed 340 Tubular reactor reactor 350 Clinker cooler

[0030] Zyklon 351 tertiary air line

[0031] Line 352 Dust collector

[0032] Clinker cooler

[0033] 400 system

[0034] Tertiary air duct

[0035] 410 heat exchanger

[0036] System 411 Heat Exchanger

[0037] Heat exchanger 420 device for preheating

[0038] Heat exchangers, calcining and sintering

[0039] Device for preheating, calcining and sintering thermal oxidation

[0040] Reactor for regenerative 440 circulating fluidized bed thermal oxidation reactor

[0041] Rotary kiln 441 cyclone

[0042] Clinker cooler 445 tubular reactor

[0043] Tertiary air line 450 clinker cooler

[0044] Dust collector 451 tertiary air line

[0045] Rotary kiln inlet chamber 500 Plant heat exchanger 611 Heat exchanger

[0046] Heat exchanger 620 Device for preheating, calcining and sintering

[0047] Device for preheating, calcining and sintering 630 Reactor for regenerative thermal oxidation

[0048] Reactor for regenerative thermal oxidation 640 Tubular reactor circulating fluidized bed 642 Deduster reactor

[0049] 640 tube reactor

[0050] cyclone

[0051] 645 rotary kiln

[0052] Line

[0053] 650 clinker coolers

[0054] rotary kiln

[0055] 651 Tertiary air duct

[0056] Clinker cooler

[0057] 660 rotary kiln inlet chamber

[0058] Tertiary air duct

[0059] 1000 separation plant

[0060] Installation and / or storage of carbon dioxide (CO2)

[0061] heat exchanger

[0062] Q Heat

Claims

PATENT CLAIMS, Plant (100, 200, 300, 400, 400, 500, 600) for producing cement clinker from raw meal, comprising at least one heat exchanger (110, 210, 310, 410, 510, 610) located downstream in the gas flow direction and at least one device (120, 220, 320, 420, 520, 620) following in the material flow direction for preheating, calcining and sintering raw meal, wherein this device can also consist of individual and successive individual devices, wherein the at least one device (120, 220, 320, 420, 520, 620) for preheating, calcining and sintering raw meal is connected to the at least one heat exchanger located downstream in the gas flow direction (110, 210, 310, 410, 510, 610) is connected on the primary side and is supplied with exhaust gas, characterized in that the at least one heat exchanger (110, 210, 310, 410, 510, 610) located downstream in the gas flow direction is connected on the secondary side to a downstream system (1000) for separating and / or storing carbon dioxide (CO2) from the exhaust gas.

2. Plant according to claim 1, characterized in that the device for preheating, calcining and sintering is a circulating fluidized bed reactor (140), a rotary kiln (240, 340), or a tubular reactor (440).

3. Plant according to claim 2, characterized in that a tubular reactor (245) is connected downstream of the rotary kiln (240) in the gas flow direction.

4. Plant according to one of claims 1 to 3, characterized in that the secondary-side plant for separating and / or storing carbon dioxide (CO2) with a steam generator for generating electrical energy generates electrical current, which supplies a device for electrolyzing water, wherein the device for electrolyzing Hydrogen (H2) is connected on the hydrogen side to a reformer in which the exhaust gas cooled in the heat exchanger and containing carbon dioxide (CO2) is converted into methanol.

5. Plant according to one of claims 1 to 4, characterized in that a tertiary air line (151, 251, 351, 451, 551, 651), which carries hot gas from a clinker cooler (151, 251, 351, 451, 551, 651), which is arranged downstream of the at least one device (120, 220, 320, 420, 520, 620) for preheating, calcining and sintering raw meal in the material flow direction, back to the at least one device (10, 220, 320, 420, 520, 620) for preheating, calcining and sintering raw meal, with a heat exchanger (111, 211, 311, 411 , 511 , 611 ), wherein the heat exchanger (111 , 211 , 311 , 411 , 511 , 611 ) is connected on the secondary side to the downstream system (1000) for separating and / or storing carbon dioxide (CO2) from the exhaust gas.

6. Method for operating a system according to claims 1 to 5, characterized in that Device for preheating, calcining and sintering raw meal is supplied with an excess of fuel and atmospheric oxygen, which leads to an exhaust gas temperature that the exhaust gas carries exactly enough heat so that the plant for separating and / or storing carbon dioxide (CO2) receives exactly the amount of energy it needs to produce the To capture and / or store carbon dioxide (CO2) produced during the production of cement clinker from raw meal.

7. Method according to claim 6, characterized by Control of fuel supply according to the exhaust gas temperature before the preheater.

8. Method according to claim 6 or 7, characterized by Treating exhaust gas from the at least one device (120, 220, 320, 420, 520, 620) for preheating, calcining and sintering raw meal in a reactor (130, 230, 330, 430, 530, 630) for regenerative thermal oxidation, and Controlling the fuel supply according to the exhaust gas temperature present upstream of the reactor (130, 230, 330, 430, 530, 630) for regenerative thermal oxidation between 800°C and 900°C, preferably 850°C with a tolerance of 20°C.

9. Process according to one of claims 6 to 8, characterized in that the fuel consists predominantly of secondary fuels, such as processed industrial waste and / or household waste, old tires, solvent waste, or processed biomass.

10. Method according to one of claims 6 to 9, characterized in that the storage also includes the chemical conversion of carbon dioxide (CO2) to other substances.

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