Patent Description:
Majority of greenhouse gas emissions come directly from industrial sources, such as manufacturing, food processing, mining, and construction. On-site combustion of fossil fuels for heat and power, non-energy use of fossil fuels, and chemical processes used in iron, steel, and cement production result in direct emissions of greenhouse gases. Fossil fuels are the largest source of air pollution emissions globally. Thus, providing non-fossil fuel-based approaches to limit greenhouse gas emissions during operation of industrial processes as Carbon- dioxide (CO2) is one of the major contributors of global warming is the need of the hour. Industry plants for metal extraction from ores, cement manufacturing and the like are major industries that need to manage the greenhouse emissions.

For example, the cement industry is classified as a hard-to-abate industry from the decarbonization perspective due to its reliance on fossil fuels and the inherent release of Carbon dioxide (CO2) from limestone during calcination. Fossil fuel is used in the process to supply the energy needed for raising the temperature of the raw material (sensible heat) to the desired level and to provide the required energy for completing the endothermic reactions. Thus, in the conventional cement manufacturing process, CO2 is generated due to the burning of the fossil fuel and calcination reaction that occurs in the calciner and rotary kiln. While the emissions from the cement industry are relatively very rich in CO2 (~<NUM> volume percent), it would still require significant investments for the installation of carbon capture facilities before it can be separated and sequestered or utilized. The industry has been depending on coal or more recently pet-coke as the energy source. To mitigate the emissions of carbon footprint, some of the plants supplement the use of coal or pet-coke with alternate fuels such as plastics, tires, and municipal wastes. The use of pet-coke also poses a significant challenge in terms of sulfur-related emissions. The residual products (ash) from the combustion make the quality monitoring in cement clinker critical. Further, depending on their composition, they may aggravate the operational challenges like volatile handing and ring formation in the rotary kilns. It is estimated that the cement industry is responsible for nearly <NUM> percent of the overall CO2 emissions.

Any effort to mitigate this and weaning this industry from the use of fossil fuel shall bear significant benefits. Attempts have been made to manage CO2 emissions, specifically in cement industry. Recent works still in research phase propose usage of Thermal Energy Storage (TES) system for required energy storage and heating of the CO2 for circulation of heat by handling CO2 release in the cement process. However, the existing approach also relies on usage of flue gases for preheaters, which requires that the calciner loop be maintained separately from the flue gas loop. It could pose challenges to avoid mixing of these gaseous streams. Further, they do not completely eliminate use of fossil fuels rather partially use flue gas or fossil fuel in the cement manufacturing process. Additional TES component increases cost of the manufacturing plant require changes to current manufacturing plants and increases manufacturing costs. The complete elimination of release of CO2 into environment by managing CO2 generated during calcination and CO2 generated from fossil fuels has hardly been addressed. Moreover, providing an implementable CO2 management solution with minimal changes to existing plant set ups is a technical challenge to be addressed.

<CIT> discloses a method of producing clinker from cement raw meal, comprising the steps of:- preheating cement raw meal in a preheater string, said preheater string comprising a plurality of preheater stages,- pre-calcining preheated raw meal in a pre-calciner to obtain a pre-calcined product,- introducing the pre-calcined product into a rotary kiln for calcining the pre-calcined product to obtain cement clinker, wherein a partial flow of at least partly preheated raw meal is diverted from the preheater string, introduced into a calcination device and at least partially decarbonated in the calcination device in order to obtain an at least partially decarbonated product and CO2, wherein the calcination device is heated by electrical energy, and wherein the at least partially decarbonated product is fed into the rotary kiln and the CO2 is drawn off from the calcination device.

<CIT> discloses a process for producing portland cement clinker from at least crushed limestone and crushed sand including the steps of: Mixing the limestone, and the sand to form a mixed powder; calcining the mixed powder in a calciner reactor, wherein the calciner reactor is adapted to apply indirect heat generated from the combustion of a first fuel input to produce the mixed powder, and wherein the calciner reactor pre-heats the mixed power in a first segment, and reacts the pre-heated powder in a second segment to generate a first gas stream of carbon dioxide from the calcination of limestone and a separate second gas stream from the combustion of the first fuel input and a stream from the mixed powder; Introducing the calcined mixed powder into a kiln using direct heating to produce Portland cement clinker, where the kiln is fueled by the combustion of a second fuel input mixed with air that is pre-heated by hot Portland cement clinker exiting the kiln.

Embodiments of the present disclosure present technological improvements as solutions to one or more of the above-mentioned technical problems recognized by the inventors in conventional systems. In one embodiment a method for electrically heated gas mixture mediated industrial plant processes is provided.

It should be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative systems and devices embodying the principles of the present subject matter. Similarly, it will be appreciated that any flow charts, flow diagrams, and the like represent various processes which may be substantially represented in computer readable medium and so executed by a computer or processor, whether or not such computer or processor is explicitly shown.

Embodiments herein provide a system for electrically heated gas mixture mediated industrial plant processes providing a fossil fuel free approach. The system utilizes a gas mixture as heating medium that directly transfers heat to a raw material required for processing the raw material into an end or an intermediate product. The gases used as the heating medium may be generated as byproduct during processing, gaseous reactants needed for processing, or a combination of stable gases that are reutilized and recirculated to carry heat and dissipate the heat at various stages of processing in accordance with a heating medium flow loop. The heating medium flow loop disclosed is designed such that it eliminates the need of heat management equipment like a Thermal Energy Storage (TES) system used by existing approaches, as electric energy is directly converted to the heat energy and passed on to the circulating gas. Entire heating of the plant is carried out using electric gas heaters heated using renewable electric sources to provide the fossil fuel free design. Furthermore, the system disclosed herein also avoids the use of two heat exchangers that that are required in the TES based approaches in the art for the indirect heating of CO2 from the calciner using the flue gas. This would be a high temperature heat exchanger that can run up the cost of the installation significantly as hot side temperature can be more than <NUM>-12000C.

<FIG> illustrates an architecture of a system <NUM> for electrically heated gas mixture mediated industrial plant processes providing a fossil fuel free approach, in accordance with some embodiments of the present disclosure. The architecture of the system <NUM> depicted in <FIG> is applicable for a multitude of industrial plant processes Examples of electrically heated gas mixture mediated industrial plant processes, are discussed below, wherein cement manufacturing plant system design is detailed for better understanding of implementation of system <NUM>. Other industrial applications of this approach can be calcination of alumina, direct reduction of iron ores, calcination of limestone, etc. The process may be carried out in different contact equipment, such as rotary kilns, fixed bed reactor, moving bed reactor, or fluidized bed reactor. The specific requirements of a particular industrial plant may need minimal changes to the main system design and fall within the scope of the electrically heated gas mixture mediated industrial plant processes disclosed herein by the general architecture of the system <NUM>. Also as understood, number of electric gas heaters, gas cleaning units and other units may vary based on the plant process.

As depicted in <FIG>, the system <NUM> comprises a process equipment <NUM>, a heat recovery unit <NUM>, a plurality of electric gas heaters <NUM> A-N, a gas recovery unit <NUM>, a gas separator <NUM>, a gas storage unit <NUM> and a plurality of gas cleaning units <NUM> A-N. The process equipment <NUM> facilitates processing of a raw material for obtaining a product. The heat required for processing the raw material is derived from a gas used as a heating medium, wherein the gas is heated electrically to a predefined temperature and the heat from the gas is transferred directly to the raw material through direct contact. The raw material may be solid state or liquid state based on type of the industrial plant. The gas identified as heating medium is either chemically inactive or participates in the reactions during processing of the raw material. The gases can be at least one of: (i) involved in the processing of the raw material as a reactant and/or a byproduct and (ii) an externally introduced stable gas, or a gas mixture thereof. As understood by person having ordinary skill in the art, the gas, the processing equipment, the raw material, and the product vary based on industrial plant process under consideration.

A plurality of electric gas heaters 104A-N, powered preferably with renewable electricity source heat the gas or gas mixture to the predefined temperature. The preheating of the gas is performed at a heat recovery unit <NUM>, wherein the heat released by the heat recovery unit during cooling of the product exiting the processing equipment is utilized to raise temperature of the gas. The heating medium flow design loop comprising of the plurality of electric gas heaters reutilizes the heat carrying capacity of the gas by recirculation and eliminates need for storing heat energy from the gas, unlike the TES systems used by few existing methods. A plurality of gas cleaning units 114A-N clean the gas before the gas enters the plurality of electric gas heaters 104A-N. An optional gas recovery unit <NUM> to recover the gas exiting the processing equipment followed by a gas separator <NUM> to separate out solid particles before venting out non-harmful gases to the environment. A gas storage unit <NUM> to store the gas exiting the gas separator <NUM>. The stored gas is recirculated as a heating medium in the heating medium flow design loop and excess gas is forwarded for sequestration for longer term storage or utilization.

The gas storage unit <NUM> includes a hollow steel tank. In this unit harmful gas is pumped and stored. This storage is used to store the excess gas from process equipment unit in the circuit. Some amount of gas is extracted from this gas storage unit <NUM> and sent to the heat recovery unit as the heating medium, interchangeably referred to hereinafter as heating medium, to start the plant operation after shutdown or periodic maintenance. The gas cleaning units 114A-N, such as cyclone separators, are used to purify the heat carrier medium coming from different units. The cleaned heat carrier medium is sent to the next corresponding electrical gas heaters 104A-N. The heat carrier medium may be preheated by the product coming out from the process equipment in heat recovery unit and sent to gas cleaning unit. In the electric gas heaters 104A-N, heat is transferred to the heat carrier medium by convection and radiation heat transfer modes. The heat carrier medium from gas cleaning unit is fed into the electric gas heaters 104A-N as input, and the heat carrier medium at high temperature, from the electric gas heaters 104A-N is fed to the process equipment unit <NUM>.

The process equipment unit <NUM> could be any industrial equipment utilizing heat from gaseous medium via direct or indirect mode to accomplish the process objective. The heat carrier medium from electric gas heaters unit is fed to process equipment unit <NUM> as input. This provides the required energy supply to the material stream to execute the process reactions or physical transformations. The raw material receives the necessary heat from the heat carrier medium stream as they move forward. The byproduct gas (if any) within the process equipment unit <NUM> is added to the heat carrier medium stream while flowing through one end to another. The product is discharged from process equipment unit <NUM> and sent to heat recovery unit <NUM> when all process reaction is completed to the required product or an intermediate product.

The gas recovery unit <NUM> comprises of a container, different stream of heat carrier medium could be mixed in case of multiple similar system have been employed in parallel. The output from the gas recovery unit is sent to the gas separator unit. The gas recovery unit <NUM> is optional depending upon the use case. These units may also serve as preheating units transferring the heat in the exhaust gases to the feed solids (raw materials). The gas separator unit <NUM> includes different separator equipment based on the mixture of gases as input to the unit. The separation of harmful gases accomplished in this unit and harmless gases (no-harmful gases) exhaust to the atmosphere. Harmful gases (after separation) are sent to the gas storage unit or sequestration for longer term storage or for future use.

Provided here are few examples that can adapt to electrically heated gas mixture mediated industrial plant processes, as disclosed herein. A rotary kiln for alumina production from aluminum trihydrate precipitate that uses hot combustion gases when adapted to electrically heated gas mixture mediated industrial plant processes is explained below. The combustion gases must be heated to approx. <NUM> degrees Celsius before entering the rotary kiln. All of the steps in the alumina process, including dehydration of the feed and endothermic decomposition of the feed via reactions, are completed by supplying heat to the raw material in the process unit via heated gases. In the conventional method, the heating of the gases is accomplished by burning the fossil fuel, such as natural gas in the rotary kiln or in separate chambers and supplying only the combustion gases. By utilizing the system <NUM> as described above, the required amount of the heating media/inert gas mixture from the storage unit is sent to the heat recovery unit to recover heat via heat transfer between the heating media and product at the discharge end. Preheated heating media is forwarded to the gas cleaning unit, which is then followed by the electric heating unit, which supplies the required heat to achieve the temperature, and heated heating media is forwarded to the processing unit. The heating media will exit from the processing unit and sent to the gas separator unit where heating media get purified and then sent to the storage unit for further circulation in the process. The purification step may involve removal of moisture produced by the calcination of trihydrate. In this system, N2 or air can be used as an inert heating media.

Referring now to design of the system <NUM> for the cement manufacturing plant or dry cement clinker, conventionally in modern dry cement clinker production based on a dry process, pulverized fuel is burnt inside a rotary kiln and pre-calciner to provide the required thermal energy. The system <NUM> disclosed herein utilizes electric energy to generate heat to be supplied to a rotary kiln and a pre-calciner unit of the cement manufacturing process.

In the example cement plant, a stable gas mixture comprising a plurality of inert gases is used as a heating medium, wherein CO2 generated as a byproduct of endothermic reaction in rotary kiln is one of the major component of the inert gases (stable gas mixture). The CO2, which is a stable or inert gas does not interfere or react with the material being processed at the industrial plant. Moreover, CO2 reuse avoids the need for an expensive carbon capture facility. The stable gas mixture, interchangeably referred to hereinafter as heating medium, is s heated or reheated electrically and passed through the rotary kiln/pre-calciner, and preheaters unlike combusting pulverized coal in the kiln/pre-calciner as used by any conventional rotary kiln. The CO2 released from the calcination reactions mixes with the heating medium. If the original heating medium itself is CO2, the released CO2 from the calcination process adds to it. Thus, major component of the heating medium is the CO2, the byproduct of the calcination and clinkerization excluding any minor emissions from raw material or air entrained in a cooler unit of the plant. The system enables the sequestration or utilization of CO2 more attractive. The system has two modes of implementation, a counter current mode and a cocurrent mode based on flow of heating medium in the rotary kiln. With elimination of fossil fuel combustion in the system disclosed herein, the extra length required for burning the fossil fuel in the rotary kiln may be reduced or may result in improved throughput for existing rotary kilns and may help make-up for the reduced kinetics due to the reversible reactions in the presence of CO2.

Electric heaters, as provided by the system disclosed herein, heat the heating medium continuously to provide the heat through heating media in the calciner and rotary kiln. Direct heating utilized in electric heaters by heating elements unlike heating a solid bed first then using that heat to heat the flowing fluid as mentioned in some of the existing methods. Using solid bed heat adds constraint in the flow rate of CO2 as it is not continuously heated. After some time, the solid bed temperature is bound to reduce, thus maintaining sufficient temperature in the bed or calciner can become a challenge. Further, the high electricity demand of the system disclosed herein is sourced preferably from renewable power supply such as solar energy to eliminate carbon emissions and provide fossil fuel free industrial heating approach.

<FIG> further explain the electrically heated gas mixture mediated industrial plant processes for the cement manufacturing plant.

<FIG> is the system <NUM> depicting a cement clinker circuit <NUM> for electrically heated gas mixture mediated industrial plant processes for a cement manufacturing plant in a counter current mode operation with example flow rate and temperature values of a heating medium made up of gas mixture, in accordance with some embodiments of the present disclosure. The example system <NUM> comprises a cement rotary kiln circuit <NUM> comprising several unit operations including the processing equipment <NUM> comprising a pre-calciner <NUM> and rotary kiln <NUM>. The cement rotary kiln circuit <NUM> further comprising a gas recovery unit <NUM>, functioning as one or more preheaters <NUM>, to obtain a preheated feed from the raw material comprising a raw meal feed entering the one or more preheaters. The cement rotary kiln circuit <NUM> further comprising the pre-calciner <NUM> for calcination of the preheated feed to obtain a partially calcined raw meal, the rotary kiln <NUM> for clinkerization to obtain the product in the form of a clinker from the partially calcined raw meal, and the heat recovery unit <NUM> in form of a cooler <NUM> to obtain the product in form of a clinker product by cooling the clinker. Here movement of the heating medium and the calcined feed in the rotary kiln <NUM> is in counter current direction.

The cement rotary kiln circuit <NUM> further comprising, the gas used as the heating medium, comprising at least one of (i) Carbon dioxide (CO2) which is byproduct of the calcination and (ii) one or more inert gases. The gas storage unit <NUM> comprises a CO2 Storage-Sequestration-Utilization Storage unit <NUM> for storing the CO2 to be reutilized by the heating medium flow design loop, wherein the excess CO2 is sent for sequestration for longer term storage or utilization. Further, the plurality of electric gas heaters 104A-N comprising a first electric gas heater (214A) and a second electric gas heater 214B. The cement rotary kiln circuit <NUM> further comprising the plurality of gas cleaning units <NUM> comprising a first gas cleaner (212A), a second gas cleaner 212B and a third gas cleaner 212C using a cyclone separator.

The cement rotary kiln circuit <NUM> further comprises a controller <NUM>, depicted in <FIG>. The controller <NUM> is configured by instructions to control the temperature of the heating medium to a plurality of predefined temperatures via the first electric gas heater 214A and the second electric gas heater 214B. Further, the controller <NUM> is configured to control a flow rate or pressure of the heating medium when the heating medium is discharged through the one or more preheaters <NUM>, the pre-calciner <NUM>, and the rotary kiln <NUM> in accordance with the heating medium flow design loop. The control of the flowrate or the pressure is performed through operations of fans or blowers or compressors (not shown) in the heating medium flow design loop.

The heating medium flow design loop execution comprising:.

<FIG> is the system <NUM> depicting the cement clinker circuit <NUM> for electrically heated gas mixture mediated industrial plant processes for the cement manufacturing plant in a cocurrent mode operation, in accordance with some embodiments of the present disclosure. Here movement of the heating medium and the calcined feed in the rotary kiln <NUM> is in cocurrent direction. The cocurrent mode operation comprises setting movement of the heating medium and the calcined feed in the rotary kiln (<NUM>) in cocurrent direction, wherein heating medium exiting the rotary kiln <NUM> is mixed with another stream of the heating medium coming from (i) the cooler <NUM> after preheating, and it is split via a flow splitter <NUM>. A first split portion of the heating medium is sent back to the rotary kiln <NUM> post performing gas purification and reheating. A second spilt portion of the heating medium is sent to second gas cleaner 212B followed by post heating to the second predefined temperature to the pre-calciner <NUM>.

As depicted in <FIG>, the cyclone separator includes a vertical cylinder with conical bottom and a vertex finder. The heating medium enters the cyclone separator tangentially near the top of the cylinder. As the fluid spirals down the cylindrical and conical sections, gaseous components move upwards, exiting through the vortex finder. The solid particles move in the radial direction as they experience greater centrifugal acceleration and exit as underflow. The cleaned heating medium is sent to the next corresponding units by the gas cleaners 212A-C, to the cooler <NUM> and electric gas heaters 114A-B in the circuit. As depicted in <FIG>, the cooler unit <NUM>, which is a grate reciprocating cooler, includes a series of fixed and movable grate plates with an inlet and outlet for the gas streams. The movable grate plates between the fixed plates are driven by the transmission devices and are responsible for the forwarding motion of clinker (clinker product). The heating medium is blown from the bottom of the clinker bed to cool the hot clinker. The exhaust gas from the cooler is heated further in the electric heaters 214A-B to the desired temperatures. The exit gas from the first electric heater 214A is directed to the rotary kiln <NUM> while the exit gas from the second electric heater 214B is directed to the pre-calciner <NUM>.

As depicted in <FIG>, the electric gas heater unit <NUM> (214A-B) include heating elements in the shape of a coil or straight tube, an arrangement for electric supply, an inlet, and an exit for the gas stream. The electricity is given to the heating elements and the heating elements in turn pass the heat to the heating medium making it reach the desired temperature. The heat is transferred to the heat carrier primarily by convection and radiation heat transfer modes. The heating medium from the cooler unit is fed into the electric gas heater units 214A-B as input, and the heated medium at high temperature, from the first electric heater 214A is fed to the rotary kiln unit <NUM> and from the second electric gas heater 114B to the pre-calciner unit <NUM> for further use. In conventional cement kilns, the overall heat load in the process of clinker production in the cement industries is approximately <NUM> KJ/ kg of clinker comes from electricity and remaining from fossil fuels. However, the cement clinker circuit disclosed herein, the load from the fossil fuels is replaced by the heating medium which is heated by electricity generated from the renewable energy sources such as solar energy. This electricity generated is used to run the electric gas heater units 214A-B, which increase the temperature of the heating medium to supply the heat in rotary kiln and pre-calciner unit operations. A sample heat load calculations for electric heaters in a cement rotary circuit are given in Table <NUM>, using CO2 gas as the heating medium in the system <NUM>. Same values are also depicted in FIG.

To provide the <NUM> kJ/kg of clinker heat load on the first electric gas heater 214A, it is estimated that required heating area is <NUM> m2. This can be achieved by five electric heaters having a one-meter length of heating elements and can be arranged according to the shown configuration in <FIG>. For the second electric gas heater 214B, as seen in <FIG>, this load is <NUM> kJ/kg of clinker and that can also be achieved by the same type of configuration with more heaters in series compared to the first electric gas heater 214A. The first electric gas heater 214A provides the heat requirement for the rotary kiln <NUM> and second electric gas heater 214B provides the heat requirement for pre-calciner unit <NUM>. As depicted in <FIG>, the rotary kiln unit <NUM> includes a cylindrical drum, inlets, and exits ports for the calcined feed and clinker. In the traditional case of counter-current flow, partially calcined material is fed from one end and high-temperature gas is injected from another end of the drum to achieve the process reactions. Alternately, the cocurrent mode, may be adopted in cement plant processes, as depicted in <FIG>, where both feed material and heating medium have cocurrent flow and are fed from the same end and leave from another end. Thus, the cement clinker circuit <NUM> caters to both types of rotary kilns <NUM> setups used in the cement industry. The clinkerization reactions occurs in the rotary kiln <NUM> as the materials move from one end to another end. The hot gas from one end provides the energy required for the process reactions primarily through radiation, convection, and conduction heat transfer (some of it through the refractory linings of the kiln). As solids move in the rotary kiln <NUM> they receive the necessary heat from the heating medium, interchangeably referred to as heat carrier medium, further sharing mass with it in the form of CO2 liberated from limestone and volatiles from the solids. The clinker product is discharged from the rotary kiln unit <NUM> and sent to the cooler unit <NUM> when all process reaction is completed to the required product compositions as shown in <FIG>. The heating medium from the rotary kiln unit <NUM> is sent to electric heater unit followed by the pre-calciner unit in case of counter current. However, the cocurrent mode the output stream is first split and then sent to the pre-calciner unit <NUM>. The heating medium from the rotary kiln unit <NUM> is sent to the first electric gas heater unit 214A, it is combined at the flow splitter <NUM> with another stream of heat carrier medium coming from the cooler after preheating, and some portion of overall heating medium after reaching the desired temperature is sent to the pre-calciner unit <NUM> to heat the solid material and assist the calcination reaction to the required extent. Thus, in <FIG> gas from rotary kiln unit <NUM> first goes into flow splitter <NUM>, where it combines with the gas from cooler <NUM> then some portion of the combined flow goes into cleaner then into the heater to achieve the desired temperature before entering the rotary kiln unit <NUM>.

As depicted in <FIG>, the pre-calciner unit <NUM> includes a tank, inlets, and outlet ports for the feed and the product. The pre-calciner unit <NUM> receives its feed material from the pre-heater(s) unit <NUM> to calcine the feed material to some extent to reduce the heat load of the rotary kiln <NUM>, thereby reduce the size of the rotary kiln <NUM>, improve the production efficiency. The feed material receives the necessary heat from the heat carrier medium, fed to the pre-calciner unit <NUM> from the rotary kiln unit <NUM> and the cooler <NUM> as shown in <FIG>. The heat carrier medium from the pre-calciner <NUM> outlet is used to preheat the solid material in the one or more preheaters <NUM>. As depicted in <FIG>, the one or more preheaters <NUM> include two inlets and two outlet ports. These are essentially gas cyclones used as heat exchangers. The raw material is fed to the unit tangentially along with the heating medium exiting the pre-calciner <NUM>. The heat transfer happens between gas and solid material as shown in <FIG>. The gas stream leaves the preheater <NUM> through vortex finder. Typically, there are five to six preheaters that are arranged in series, located one on top of the other, are used. While the solids travels downwards from one preheater to another and finally to the pre-calciner <NUM>, the gas stream travels to the earlier stage of preheater. The gas stream that is exiting the first preheater is sent to the gas separator unit where CO2 gas separated from dust and other gases (when a gas mixture is used). A major part of the gas stream is recycled back to the cooler <NUM> to act as the heating medium. A portion of is recovered and sent to the storage unit <NUM> for CO2 sequestration/storage units after passing through an electrostatic precipitator (ESP) unit. As depicted in <FIG>, the electrostatic precipitator (ESP) unit includes gas distribution plates, discharge electrodes, collection surfaces (either plates or pipes), and rappers. The gas distribution plates maintain the flow distribution of the input gas, and the discharge electrode is divided into electric fields depending on the ESP capacity and energized by the set power supply, these discharge electrodes generate the ions which collide with the particles present in the gas and apply an electrical charge to them. The charged dust particles are collected on the collection surface and rappers are used to remove the dust particles from the collection surface. The clean gas leaves the circuit as shown in <FIG>.

<FIG> is a functional block diagram of the controller <NUM> that controls the temperature, pressure, or the flow rate of the heating medium of cement clinker circuit <NUM>, in accordance with some embodiments of the present disclosure.

In an embodiment, the controller <NUM> includes a processor(s) <NUM>, communication interface device(s), alternatively referred as input/output (I/O) interface(s) <NUM>, and one or more data storage devices or a memory <NUM> operatively coupled to the processor(s) <NUM>. The controller <NUM> with one or more hardware processors is configured to execute functions of one or more functional blocks of the controller <NUM>.

Referring to the components of controller <NUM>, in an embodiment, the processor(s) <NUM>, can be one or more hardware processors <NUM>. In an embodiment, the one or more hardware processors <NUM> can be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, state machines, logic circuitries, and/or any devices that manipulate signals based on operational instructions. Among other capabilities, the one or more hardware processors <NUM> are configured to fetch and execute computer-readable instructions stored in the memory <NUM>. In an embodiment, the controller <NUM> can be implemented in a variety of computing systems including laptop computers, notebooks, hand-held devices such as mobile phones, workstations, mainframe computers, servers, and the like.

The I/O interface(s) <NUM> can include a variety of software and hardware interfaces, for example, a web interface, a graphical user interface to display the heating medium temperature and flow rates acquired via a set of sensors monitoring the process of the system <NUM>. The I/O interface <NUM> can facilitate multiple communications within a wide variety of networks N/W and protocol types, including wired networks, for example, LAN, cable, etc., and wireless networks, such as WLAN, cellular and the like. In an embodiment, the I/O interface (s) <NUM> can include one or more ports for connecting to a number of external devices or to another server or devices.

The memory <NUM> may include any computer-readable medium known in the art including, for example, volatile memory, such as static random access memory (SRAM) and dynamic random access memory (DRAM), and/or non-volatile memory, such as read only memory (ROM), erasable programmable ROM, flash memories, hard disks, optical disks, and magnetic tapes. In an embodiment, the memory <NUM> includes a plurality of modules <NUM> such as modules for temperature, flow monitoring of the heating medium. The plurality of modules <NUM> further include programs or coded instructions that supplement applications or functions performed by the controller <NUM> for executing different steps involved in the process of the inert gas based direct heating for the industrial plant process, being performed by the controller <NUM>. The plurality of modules <NUM>, amongst other things, can include routines, programs, objects, components, and data structures, which performs particular tasks or implement particular abstract data types. The plurality of modules <NUM> may also be used as, signal processor(s), node machine(s), logic circuitries, and/or any other device or component that manipulates signals based on operational instructions. Further, the plurality of modules <NUM> can be used by hardware, by computer-readable instructions executed by the one or more hardware processors <NUM>, or by a combination thereof.

Further, the memory <NUM> may comprise information pertaining to input(s)/output(s) of each step performed by the processor(s) <NUM> of the controller <NUM> and methods of the present disclosure. Further, the memory <NUM> includes a database <NUM>. The database (or repository) <NUM> may include a plurality of abstracted piece of code for refinement and data that is processed, received, or generated as a result of the execution of the plurality of modules in the module(s) <NUM>.

Although the data base <NUM> is shown internal to the controller <NUM>, it will be noted that, in alternate embodiments, the database <NUM> can also be implemented external to the controller <NUM>, and communicatively coupled to the controller <NUM>. The data contained within such external database may be periodically updated. For example, new data may be added into the database (not shown in <FIG>) and/or existing data may be modified and/or non-useful data may be deleted from the database. In one example, the data may be stored in an external system, such as a Lightweight Directory Access Protocol (LDAP) directory and a Relational Database Management System (RDBMS).

The controller <NUM> configured by the instructions to control the temperature of the heating medium to the plurality of predefined temperatures via the first electric gas heater (214A) and the second electric gas heater (214B). Further is configured to control the flow rate or the pressure of the heating medium when the heating medium is discharged through the one or more preheaters <NUM>, the pre-calciner <NUM>, and the rotary kiln <NUM> in accordance with the heating medium flow design loop, wherein control of the flowrate or the pressure is performed through operations of fans or blowers in the heating medium flow design loop.

Thus, the means can include both hardware means, and software means.

Claim 1:
A method for fossil fuel free heating in a cement manufacturing plant, the method comprising:
obtaining a product by processing a raw material at a process equipment (<NUM>), wherein heat required for processing the raw material is derived from a gas used as a heating medium, wherein the gas is heated electrically to a predefined temperature, wherein the heat from the gas is transferred directly to the raw material through direct contact, wherein the gas is chemically inactive or participating in the reactions during processing of the raw material, and wherein the gas is at least one of: (i) involved in the processing of the raw material as a reactant and/or a byproduct, and (ii) an externally introduced stable gas, or a gas mixture thereof;
heating the gas to the predefined temperature at a plurality of electric gas heaters (104A-N), powered with electricity source, where preheating of the gas is performed at a heat recovery unit (<NUM>), wherein the heat released by the heat recovery unit during cooling of the product exiting the processing equipment is utilized to raise temperature of the gas, and wherein a heating medium flow design loop comprising of the plurality of electric gas heaters reutilizes the heat carrying capacity of the gas by recirculation and eliminates need for storing heat energy from the gas;
cleaning the gas before entering the plurality of electric gas heaters (104A-N) at a plurality of gas cleaning units (114A-N);
recovering the gas, at an optional gas recovery unit (<NUM>), exiting the processing equipment followed by a gas separator (<NUM>) to separate out solid particles before venting out non-harmful gases to the environment; and
storing the gas exiting the gas separator (<NUM>) at a gas storage unit (<NUM>), wherein the stored gas is recirculated as a heating medium in the heating medium flow design loop and excess gas is forwarded for sequestration for longer term storage or utilization.