Method and apparatus for filtered combustion

Abstract

A method of producing clinker includes placing a pre-clinker mixture including a source of CaO into a starting material feed port in a vertically oriented reaction chamber of a vertical reactor. The method includes placing a gaseous combustion mixture into a combustion mixture inlet. The method includes combusting a gaseous combustion mixture within a vertical reactor to heat a pre-clinker mixture, releasing CO2 therefrom, and forming clinker therefrom. The method further includes removing clinker from the product outlet.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 391,632, filed on July 22, 2022, the disclosure of which is incorporated herein by reference in its entirety. Background Art

[0003] Cement manufacturing remains one of the most energy-intensive and CO2-emitting industrial processes. Clinker combustion is a mature industrial process invented more than a century ago, with most modern clinker combustion systems consisting of a cyclone-based preheating and calcining system, a rotary kiln that sintered the calcined material at approximately 1450°C, and a clinker cooler. Over the past four decades, the efficiency of cement rotary kilns has been gradually improved through separation of raw calcination and clinkerization processes, gas bypass systems, and waste heat recovery systems. In summary, segmentation of the process and optimization of each step can increase improvements in efficiency. However, this is achieved at the expense of scale and additional capital costs. Due to the large-scale nature of current cement plants and technologies, it is common for cement companies to build at peak capacity and often in excess of supply. As a result, local cement prices have fallen, and cement companies across regions are operating at a loss due to insufficient plant productivity. Therefore, there is a long-standing unmet need to be able to deploy cement production incrementally and capital efficiently.

[0004] In addition, there are several long-standing and growing business issues for the current cement industry, such as increased carbon regulations. Pressure from governments has created an increasing but unmet demand for the cement industry to find low-carbon and low-cost ways to reduce the carbon footprint of cement production.

[0005] Previous attempts to address these long-standing and growing overcapacity and carbon footprint issues have largely failed to address them on a commercial scale, both technically and economically. The reasons for these failures are many, but they do not present the following combination of the necessary criteria: 1) a path to net-zero emissions, 2) low-cost cement production, 3) no regulatory barriers (through production of ordinary Portland cement), and 4) modularity / adaptability, to name a few.

[0006] At the beginning of the 20th century, small vertical kilns of the order of magnitude of 5 tons / day to 200 tons / day were common for cement manufacturing. However, compared with modern large rotary kilns producing about 2000 tons / day to about 3000 tons / day, these previous small kilns have several problems, defects and shortcomings, such as restrictions on solid fuels, lower operating efficiency, poorer product quality, poorer product consistency and more emissions and higher operating costs. They are the main producers of CO2 and greenhouse gases, and particularly with respect to their productivity, small kilns are very major polluters. Therefore, they have not been widely used since the 1970s.

[0007] Vertical shaft kilns have been used for cement clinker manufacturing since the 19th century. However, due to challenges with scaling, clinker quality and air emission control, VSKs have not been widely used since the 1970s. Summary of the invention

[0008] Various aspects of the present invention provide a method for producing clinker. The method includes placing a pre-clinker mixture including a source of CaO into a starting material feed port in a reaction chamber of a vertical reactor. The vertical reactor includes a vertically oriented longitudinal axis of the reaction chamber, a product outlet, a gaseous combustion mixture inlet into the reaction chamber, and one or more exhaust ports. The method includes placing the gaseous combustion mixture into the gaseous combustion mixture inlet. The method includes burning the gaseous combustion mixture in the vertical reactor to heat the pre-clinker mixture, releasing CO2 therefrom, and forming clinker therefrom. The method also includes removing clinker from the product outlet.

[0009] Various aspects of the present invention provide a method for producing a product. The method includes placing a starting material mixture into a starting material feed port in a reaction chamber of a vertical reactor. The vertical reactor includes a vertically oriented longitudinal axis of the reaction chamber, a product outlet in the reaction chamber, a gaseous combustion mixture inlet into the reaction chamber, and one or more exhaust ports in the reaction chamber. The method includes placing the gaseous combustion mixture into the gaseous combustion mixture inlet. The method includes burning the gaseous combustion mixture in the vertical reactor to heat the starting material mixture and form products therefrom. The method also includes removing the product from the product outlet.

[0010] Various aspects of the present invention provide an apparatus. The apparatus comprises a reaction chamber having a vertically oriented longitudinal axis. The apparatus comprises a starting material feed port. The apparatus also comprises a gaseous combustion mixture inlet into the reaction chamber for injecting a gaseous combustion mixture therein.

[0011] Porous media combustion is a fuel oxidation process in which a solid porous media within the burner is able to recover heat from the combustion products and preheat the incoming reactants. This internal heat recovery extends the limits of standard flammability and enables the combustion of ultra-lean and ultra-rich fuel-oxidant mixtures. Research on porous media combustion (primarily on a university laboratory scale) has focused on hydrogen or syngas production, efficient water heating systems, VOC dispersion, and / or heat sources for thermoelectric generation.

[0012] Various aspects of the present invention are different from other methods and apparatus for porous media combustion using inert media. Conventional porous burner media combustion processes utilize inert media to maintain combustion, such as alumina spheres or monolithic porous foams. The methods and apparatus of the present invention can maintain combustion without adding any inert media such as inert porous media or inert burner media to maintain combustion. The starting material mixture (e.g., pre-clinker mixture) and its intermediates and products in the reactor can maintain combustion in the reactor without applying an external heat source. In various aspects, the methods of the present invention and the apparatus for performing the methods can provide products (e.g., clinker) at higher efficiency and lower cost than conventional methods, such as compared to rotary kiln methods. In various aspects, the methods and apparatus of the present invention can reduce or eliminate the emission of pollutants generated by solid combustion mixtures (e.g., coal) used in conventional clinker production processes.

[0013] In various aspects, the methods and apparatus of the present invention can be used in various processes and are not limited to clinker production. For example, the methods and apparatus of the present invention can be used to calcine a source of CaO (e.g., CaCO3) to produce lime, calcining to desorb CO2 from any carbonate rock in a direct air capture system, sintering refractory materials, producing lithium through spodumene, or direct reduction iron processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The drawings generally illustrate various aspects of the invention by way of example and not limitation.

[0015] Figure 1A A vertical reaction chamber including a calcination zone and a clinkering zone according to various aspects is shown.

[0016] Figure 1BA vertical reaction chamber including a calcining zone and a clinkering zone according to various aspects is shown.

[0017] Figure 1C A vertical reaction chamber including a single combustion wave according to various aspects is shown.

[0018] Figure 2 An apparatus for producing clinker according to various aspects is shown.

[0019] Figure 3 Diagrams showing reaction chambers filled with porous media according to various aspects.

[0020] Figure 4 The efficiency and V_inlet of a simulated reactor at an equivalence ratio of 0.7 are shown according to various aspects.

[0021] Figure 5 The efficiency and equivalence ratio of simulated reactors according to various aspects are shown at a V-inlet of 0.5 m / s. DETAILED DESCRIPTION

[0022] Reference will now be made in detail to certain aspects of the disclosed subject matter, examples of which are partially illustrated in the accompanying drawings.While the disclosed subject matter will be described in conjunction with the enumerated claims, it will be understood that the illustrated subject matter is not intended to limit the claims to the disclosed subject matter.

[0023] In this article, the values ​​expressed in the range format should be interpreted in a flexible manner to include not only the numerical values ​​clearly recorded as range limits, but also all individual numerical values ​​or sub-ranges contained in the range, as if each numerical value and sub-range were clearly recorded. For example, the range of "about 0.1% to about 5%" or "about 0.1% to 5%" should be interpreted as not only including about 0.1% to about 5%, but also including the individual values ​​(e.g., 1%, 2%, 3% and 4%) and sub-ranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within the indicated range. Unless otherwise specified, the expression of "about X to Y" has the same meaning as the expression of "about X to about Y". Similarly, unless otherwise specified, the expression of "about X, Y or about Z" has the same meaning as the expression of "about X, about Y or about Z".

[0024] In this article, unless the context clearly stipulates otherwise, the terms "one", "an" or "the" are used to include one or more. Unless otherwise specified, the term "or" is used to refer to a non-exclusive "or". The expression "at least one of A and B" or "at least one of A or B" has the same meaning as the expression "A, B, or A and B". In addition, it should be understood that the words or terms used in this article and not otherwise defined are used for description only and not for limitation. The use of any section headings is intended to assist in reading this article and is not to be interpreted as a limitation; information related to the section headings may appear within or outside the particular section. All publications, patents, and patent documents mentioned herein are incorporated herein in their entirety by reference, as if incorporated herein by reference alone. In the event of inconsistency between the usage of this article and the documents incorporated by reference, the usage in the incorporated references should be considered to supplement the usage of this article; for irreconcilable inconsistencies, the usage in this article shall prevail.

[0025] In the methods described herein, unless a time or sequence of operations is explicitly listed, actions may be performed in any order without departing from the principles of the invention. In addition, specific actions may be performed simultaneously unless the explicit claim language states that they may be performed separately. For example, an action required to do X and an action required to do Y may be performed simultaneously in a single operation and the resulting process will fall within the literal scope of the required process.

[0026] As used herein, the term "about" can allow for a certain degree of variability in values ​​or ranges, for example, within 10%, within 5%, or within 1% of a specified value or specified range limit and including the exact specified value or range. As used herein, the term "substantially" refers to a majority or a large portion, such as at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more, or 100%. As used herein, the term "substantially free" may mean free of or containing trace amounts such that the amount of material present does not affect the material properties of the composition comprising the material, such that about 0% to about 5% by weight of the composition is the material, or about 0% to about 1% by weight, or about 5% by weight or less, or less than or equal to about 4.5%, 4%, 3.5%, 3%, 2.5%, 2%, 1.5%, 1%, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, 0.1%, 0.01%, or about 0.001% by weight or less, or about 0% by weight is the material.

[0027] Method for producing clinker

[0028] Various aspects of the present invention provide a method for producing clinker. The method may include placing a pre-clinker mixture including a source of CaO into a starting material feed port in a reaction chamber of a vertical reactor, wherein the vertical reactor includes a vertically oriented longitudinal axis of the reaction chamber, a product outlet, a gaseous combustion mixture inlet into the reaction chamber, and one or more exhaust ports. The method includes placing the gaseous combustion mixture into the gaseous combustion mixture inlet. The method includes burning the gaseous combustion mixture in the vertical reactor to heat the pre-clinker mixture, releasing CO2 therefrom, and forming clinker therefrom. The method also includes removing clinker from the product outlet.

[0029] The vertical reactor can be a gravity feed reactor. The vertically oriented longitudinal axis of the reaction chamber can form an angle of 45 ° to 90 ° with the horizontal axis, or 70 ° to 90 °, or 80 ° to 90 °, or 85 ° to 90 °. The starting material feed port can be located at any suitable part of the reaction chamber, such as the top or bottom of the reaction chamber. One or more exhaust ports can be located at any suitable part of the reaction chamber, such as the top, the middle part, the bottom or a combination thereof. The product outlet can be located at any suitable part of the reaction chamber, such as the top of the reaction chamber or the bottom of the reaction chamber.

[0030] The method for producing clinker is a filtered combustion method. Filtered combustion can include superadiabatic combustion, non-superadiabatic combustion, or a combination thereof. Filtered combustion, also known as porous media combustion, is a method for partial or complete oxidation of a fuel in the presence of a solid phase, for example wherein the solid phase and the fuel flow in a counter-current manner.

[0031] In various aspects, the method may include superadiabatic combustion of a gaseous combustion mixture in a vertical reactor. As used herein, "superadiabatic combustion" of a gaseous composition in a reactor refers to a starting material mixture (e.g., a pre-clinker mixture), an intermediate formed thereby, and / or a product formed thereby (e.g., clinker) that obtains a temperature in the reactor that exceeds the adiabatic flame temperature of the gaseous combustion mixture. The superadiabatic combustion of the gaseous combustion mixture is sufficient to maintain combustion without applying any external heat source to the reactor, so that internal heat recovery is sufficient to maintain combustion. The external heat source is a heat source outside the vertical reactor and / or the reaction chamber, wherein heat is transferred into the reaction chamber. The external heat source may include, for example, a burner, an electric heater, etc. The method may not apply external heat to the reaction chamber. In some embodiments, it may be necessary to initially apply external heat to start combustion, but once combustion is started, combustion is self-sustaining without any external heat source. Superadiabatic combustion may occur on a pre-clinker mixture and / or in a pre-clinker mixture. The preclinker mixture may sustain superadiabatic combustion at least by achieving a temperature in and / or on the preclinker mixture that is higher than the adiabatic flame temperature of the gaseous combustion mixture.

[0032] In other aspects, the method can be non-superadiabatic (e.g., subadiabatic) combustion of a gaseous combustion mixture in a vertical reactor, so that the starting material mixture (e.g., preclinker mixture), the intermediates formed therefrom and / or the products formed therefrom (e.g., clinker), if measured in the absence of an external heat source, obtain a temperature in the reactor equal to or lower than the adiabatic flame temperature of the gaseous combustion mixture. The non-superadiabatic combustion of the gaseous combustion mixture is sufficient to maintain combustion without applying any external heat source to the reactor, so that internal heat recovery is sufficient to maintain combustion. The method can be without applying external heat to the reaction chamber. In some embodiments, it may be necessary to initially apply external heat to start the non-superadiabatic combustion, but once the combustion is started, the combustion is self-sustaining without any external heat source. Non-superadiabatic combustion can occur on and / or in the preclinker mixture. The preclinker mixture can maintain non-superadiabatic combustion at least by achieving a temperature high enough to maintain the combustion of the gaseous combustion mixture without applying an external heat source.

[0033] The preclinker mixture includes a source of CaO. The source of CaO may include CaCO3. The source of CaO may include limestone (e.g., inorganic or fossiliferous sedimentary limestone, metamorphic rock, and igneous carbonate rock), calcium silicate minerals (e.g., wollastonite) and / or calcium aluminosilicate (e.g., slag or calcium feldspar). The preclinker mixture may include other sources of CaO. The preclinker mixture may also include SiO2, Al2O3, Fe2O3, SO3, MgO, P2O5, or a combination thereof. The preclinker mixture may optionally include impurities such as Na2O, K2O, TiO2, oxides of Mn, oxides of Cr, etc., or a combination thereof. The preclinker mixture may include raw preclinker materials and / or calcined intermediates formed before clinker.

[0034] Conventional porous media combustion processes include the use of inert porous burner media that achieves high temperatures and maintains combustion of the combustion composition without the application of external heating. A unique feature of the present method and apparatus is that combustion can occur without the addition of an inert porous burner media. The method and apparatus can dispense with the addition of an inert porous burner media and can include placing only a starting material mixture (e.g., a preclinker mixture) and a gaseous combustion mixture into a reaction chamber. The starting material mixture, such as a preclinker mixture, and its intermediates and products generated within the column when the starting material mixture is heated in the reaction chamber, provide the same functionality as conventional inert porous burner media and maintain combustion in the reaction chamber without the application of external heat. The heat of combustion can be absorbed by the starting material mixture and the intermediates and products formed therefrom, and / or the walls of the reaction column, and the absorbed heat is sufficient to preheat and maintain combustion of the incoming gaseous combustion mixture without the application of external heat.

[0035] The gaseous combustion mixture can be any suitable gaseous combustion mixture that can withstand continuous combustion in the reaction chamber without an external heat source. The gaseous combustion mixture can include a mixture of a fuel and an oxidant (e.g., one or more fuels and one or more oxidants). The gaseous combustion mixture may not contain solid fuels. In addition to the pre-clinker mixture, the reaction chamber may not contain solid fuels (e.g., may not contain coal or other conventional solid fuels for clinker production). The gaseous combustion mixture may include C1-C5 hydrocarbons, H2, O2, N2, CO2, CO or a combination thereof. The gaseous combustion mixture may include N2, CO2, O2 or a combination thereof. The gaseous combustion mixture may include biogas, synthesis gas, another gaseous fuel or a combination thereof. The gaseous combustion mixture may include air (e.g., 20.9% O2 and balance N2), oxygen-enriched air (e.g., 21% to 50% O2 and balance N2), synthetic air (e.g., 20.9% O2 and balance CO2), oxygen-depleted synthetic air (e.g., 17% to 20% O2, balance CO2), or oxygen-enriched synthetic air (e.g., 21% to 50% O2, balance CO2), or a combination thereof. In some embodiments, the method may further include placing a solid fuel (e.g., coal) into the reaction chamber. In some embodiments, the method has no solid fuel in the reaction chamber other than the starting material mixture (e.g., preclinker mixture).

[0036] The preclinker mixture can have any suitable physical form. The preclinker mixture can be particulate or granular. The preclinker mixture can have a particle size (e.g., the number average of the maximum size of the free-flowing particles) of about 1 mm to about 50 mm, or about 3 mm to about 15 mm, or less than or equal to 50 mm and greater than or equal to 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 22 mm, 24 mm, 26 mm, 28 mm, 30 mm, 32 mm, 34 mm, 36 mm, 38 mm, 40 mm, 42 mm, 44 mm, 46 mm or 48 mm. The preclinker mixture and the produced clinker can form a packed bed in the reaction chamber, which moves downward at a speed approximately the same as the speed at which the combustion wave moves upward through the reaction chamber, producing an approximately stationary combustion wave. The preclinker mixture may be granulated by any suitable process, for example by agglomeration, briquetting, compaction and granulation and / or extrusion granulation. The preclinker mixture may be agglomerates or lumps having a particle size of about 1 mm to about 50 mm, or about 3 mm to about 15 mm. The preclinker mixture particulate matter or particles may be agglomerated or agglomerated from smaller particles (e.g., particles formed by grinding and / or comminution), such as particles having a particle size of about 0.001 microns to about 100 microns, or about 1 micron to about 100 microns, or less than or equal to 100 microns and greater than or equal to 0.001 microns, 0.005 microns, 0.01 microns, 0.05 microns, 0.1 microns, 0.5 microns, 1 micron, 2 microns, 3 microns, 4 microns, 5 microns, 6 microns, 8 microns, 10 microns, 12 microns, 14 microns, 16 microns, 18 microns, 20 microns, 25 microns, 30 microns, 35 microns, 40 microns, 45 microns, 50 microns, 55 microns, 60 microns, 65 microns, 70 microns, 75 microns, 80 microns, 85 microns, 90 microns or 95 microns. The particles or agglomerates may be held together by compression (extrusion), a binder, moisture, or a combination thereof. In various embodiments, the particles may fill about 70% to about 100% of the reaction chamber of the vertical reactor. The particles or agglomerates may be of any suitable shape, such as spherical, oval, cubic, or other shapes, such as shapes with increased or optimized surface area and physical integrity. The increased surface area may increase the rate of heat transfer to the particles or agglomerates.

[0037] The preclinker material may be preheated by upwardly rising gaseous products from the combustion of gases occurring below in the reaction column. Preheating may be provided without the application of any external heat source.

[0038] Forming clinker from the preclinker mixture may include forming CaO from CaCO3 with the concomitant release of CO2. Forming clinker from the preclinker mixture may include forming products from the produced CaO and other materials in the preclinker mixture, such as (for example) forming products such as 2CaO·SiO2, 3CaO·SiO2, 3CaO·Al2O3, 4CaO·Al2O3·Fe2O3, CaO·Al2O3, 12CaO7·Al2O3, 2CaO·Al2O3, 4CaO3·Al2O3SO3 or combinations thereof. Forming clinker from the preclinker mixture may include calcining (e.g., releasing CO2), clinkering (e.g., producing 2CaO·SiO2, 3CaO·SiO2, 3CaO·Al2O3, 4CaO·Al2O3·Fe2O3, CaO·Al2O3, 12CaO7·Al2O3, 2CaO·Al2O3, 4CaO3·Al2O3SO3, or combinations thereof), or combinations thereof. Clinker or clinker phases may include other oxides as impurities; for example, a 2CaO·SiO2 phase may be present in the produced clinker or cement in the form of (2-x)CaO.yMgO.(1-z)SiO2·mAl2O3·nFe2O3·pNa2O·qK2O, where x, y, z, m, n, p, q are 0 or very small integers. Such phases may also include other minor impurities, such as (but not limited to) oxides of Ti, Mn, Cr, and Zn.

[0039] The heating of the preclinker mixture for combustion to form clinker therefrom may be performed at any suitable temperature so that clinker is formed. For example, the heating may include heating the preclinker mixture to 2282°F (1250°C) to 2732°F (1500°C), or 1472°F (800°C) to 3632°F (2000°C). In various aspects, the heating may be at or below 3632°F (2000°C), for example to accommodate various raw material mixtures and / or other processes.

[0040] The bottom of the vertical reactor may cool the clinker before it is removed from the product outlet. The cooling of the clinker may include absorbing heat from the clinker by the pre-clinker mixture.

[0041] While flowing through the clinker cooling zone, the gaseous combustion mixture is preheated to the ignition temperature required to start combustion of the gaseous combustion mixture. The combustion process generated is sufficient to generate heat and maintain the operating temperature required for the clinkering process. The heat released during the combustion and clinkering process can move through the porous bed as a heat wave, allowing the combustion wave to move upward through the reaction chamber at the same speed and in the opposite direction as the porous bed moves from the top of the kiln down to the discharge at the bottom of the kiln. From the observer's reference frame, the result may be a stationary combustion wave. The heat generated during the fuel combustion and clinkering process is used for raw material preheating and calcining.

[0042] The combustion process can be started in any suitable manner. In one embodiment, the combustion mixture can flow through the porous medium and ignite at one end of the reactor. The combustion mixture can then be adjusted to allow the combustion wave to enter the body of the reactor. In another embodiment, an external heat source can be used to preheat a portion of the porous medium to above the autoignition temperature of the combustion mixture. The combustion mixture can then flow into the reactor to initiate combustion in the porous medium. Once the reactor reaches a steady-state operating mode, the method and apparatus can maintain the combustion of the gaseous combustion material therein and the clinker production of the pre-clinker starting material without applying an external heat source.

[0043] The parameters of SAC, including the combustion zone / combustion wave temperature and the combustion wave propagation velocity, are mainly determined by the oxygen concentration in the oxidant, the ratio of oxidant to fuel (usually expressed as the equivalence ratio (A V / F V ) stoic / (A V / F V ) act , where (A V / F V ) stoic is the stoichiometric oxidant to fuel ratio (volume basis) and (A V / F V ) act is the actual oxidant to fuel ratio (volume basis)), the filtration velocity v of the combustion reactant mixture f Alternatively, it may be determined by the structure and thermal properties of the porous medium (eg, starting material mixture or preclinker mixture) including medium density, particle size, thermal conductivity.

[0044] The equivalence ratio of the combustion mixture introduced at the bottom of the Super Adiabatic Kiln (SAK) can be maintained in the range of 0.3 to 5 and the combustion wave is expected to travel at a speed of 0.1 mm to 10 mm per minute. If necessary, additional fuel and / or oxidant can be introduced into the secondary zone downstream of the clinkering process to provide additional heat for the calcining process, which is also called staged combustion. The combustion in the secondary zone can be superadiabatic or non-superadiabatic.

[0045] The shape, maximum temperature and position of the temperature profile produced by the primary and secondary combustion waves can be optimized for efficient and high quality clinker production. The combustion wave parameters and the resulting temperature profile can be effectively controlled by the air-fuel ratio, filter rate, oxidant composition to compensate for changes in the raw material composition and / or changes in the original size of the starting material mixture particles or granules / agglomerates. Shrinkage caused by the calcination process resulting in changes in particle density, particle shape, particle porosity, bulk density (packing density) and / or void space ratio can also be compensated.

[0046] The reaction chamber may include a combustion zone (e.g., a combustion wave). In some aspects, the reaction chamber includes one and no more than one combustion wave, wherein calcination and clinkering may occur in the same combustion wave. In some aspects, the reaction chamber includes two or more combustion waves. In one example, a reaction chamber having two combustion waves includes: a first combustion wave including a calcination zone and a second combustion wave including a clinkering zone. The second combustion wave may be below the first combustion wave. In various embodiments, the method includes maintaining a temperature at or below about 3632℉ (2000℃). In some aspects, the calcination zone may have a temperature of about 1472℉ (800℃) to about 2012℉ (1100℃). In some aspects, the clinkering zone or a combined calcination and clinkering zone may have a temperature of about 2282℉ (1250℃) to 2912℉ (1600℃), or 2282℉ (1250℃) to 3632℉ (2000℃).

[0047] The reaction chamber may include a single combustion mixture inlet or multiple combustion mixture inlets. The gaseous combustion composition injected into each separate injection inlet may be a combination of fuel and oxidant, or just fuel, or just oxidant, as long as the fuel and oxidant are combined in the column. In some aspects, the reaction chamber includes a combustion mixture inlet at the bottom of the reaction chamber and a combustion mixture inlet at the center of the reaction chamber. Multiple combustion mixture inlets can be used to control whether there is a single combustion wave or multiple combustion waves in the reaction chamber.

[0048] The method may include operating the vertical reactor in batch mode. The method may include operating the vertical reactor in continuous mode. In batch mode, the reactor may be fully loaded with green particles of a preclinker mixture, combustion is initiated at the bottom of the reactor, a combustion wave travels from the bottom to the top of the particle bed, thereby converting the starting material mixture into clinker, and the clinker is then discharged from the bottom of the reaction chamber. In batch mode, the combustion wave moves through a fixed bed of the preclinker mixture.

[0049] In various aspects, the combustion wave is maintained as a stationary combustion wave as the preclinker mixture moves downward through the reaction chamber. In other aspects, the propagation speed of one or more combustion waves can be controlled individually or switched in unison. Individual control can be produced by changing parameters at more local injection points (e.g., secondary injection, tertiary injection, etc.). By changing parameters at more global injection points (mainly the main injection point), the speed can be switched in unison. Typically, the speed does exceed 20 mm / min. For the clinkering process, the speed can take any value in the range of 0.001 mm to 10 mm per minute, such as 0.1 mm to 10 mm per minute or 1 mm to 10 mm per minute.

[0050] The combustion wave can be oriented perpendicular to the central vertical axis of the reaction chamber. In other aspects, the combustion wave can be tilted by locally changing a propagation velocity parameter.

[0051] The combustion wave can span the entire inner diameter of the reaction chamber. In some aspects, the combustion wave or combustion wave can be less than the entire cross-sectional area of ​​the reaction chamber, such as by localizing the combustion wave around the fuel injection point so that combustion occurs before the combustible gas is evenly diffused throughout the cross-sectional area.

[0052] Figure 1A A vertical reaction chamber including a calcination zone and a clinkering zone according to various aspects is shown. Figure 1B A vertical reaction chamber including a calcining zone and a clinkering zone according to various aspects is shown. Figure 1C A vertical reaction chamber including a single combustion wave according to various aspects is shown.

[0053] The method may include monitoring the temperature and position of the combustion wave. Monitoring may include high resolution spectrometry (for applications greater than 1700°C) or the use of ceramic sheathed thermocouples. Regardless of the method, the maximum temperature and position of the combustion wave may be determined using temperature sensors oriented along the length of the kiln. Thermocouples oriented around the periphery of the kiln may be used to determine the angle of the combustion wave. Various aspects of the present invention including maintaining multiple combustion waves (e.g., using separate waves to control calcination and clinkering / sintering) may include locating and characterizing each combustion wave / combustion zone.

[0054] Additional injection locations (e.g., for fuel, oxidant, or both) may also be used to assist in maintaining the combustion wave. By introducing process gas at different locations, it is possible to: control the local equivalence ratio, stabilize the combustion wave and promote uniform wave propagation through the material bed, and / or form multiple combustion waves.

[0055] For example, the first (upstream) wave can be run rich (with a high equivalence ratio). A secondary injection of oxidant above the first wave (downstream) can form a second wave with unreacted fuel. A similar effect can be achieved with a lean first wave and secondary injection of fuel. This process can be repeated for any number of combustion waves.

[0056] The manner in which the process gas is introduced also contributes to the control of the combustion wave. Variable velocity gas injection can be used to induce turbulence in the filtered gas and promote uniform mixing of the reactants. This effect can be synthesized by injecting the gas non-radially (off-center), thereby creating a vortex effect within the reactor.

[0057] Examples of aspects of the present method that may improve or optimize feedstock preheating, calcination, clinker combustion and / or cooling may include controlling: filtration rate, combustion rate, equivalence ratio, oxygen concentration in the oxidant, secondary air and fuel injection, feedstock feed rate, feedstock particle size and thermophysical properties, and / or feedstock composition and preparation process.

[0058] In various aspects, the method for producing clinker can be operated at an efficiency of 50% to 95%, or 65% to 90%, or less than or equal to 95% and greater than or equal to 50%, and less than, equal to or greater than 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 88%, 90%, 92% or 94%. The method can be performed using an equivalence ratio of fuel to air in the gas combustion mixture of 0.1 to 0.9, or 0.5 to 0.8, or less than or equal to 1 and greater than or equal to 0, and less than, equal to, or greater than 0.1, 0.2, 0.3, 0.4, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9 or 0.95. The method can be carried out using a suitable velocity of the gaseous combustion mixture relative to the wall of the reactor, for example 0.1 m / s to 20 m / s, or 0.4 m / s to 5 m / s, or 0.5 m / s to 2.5 m / s, or less than or equal to 20 m / s and greater than or equal to 0.1 m / s, and a velocity less than, equal to or greater than 0.5 m / s, 1 m / s, 1.5 m / s, 2 m / s, 2.5 m / s, 3 m / s, 4 m / s, 5 m / s, 6 m / s, 7 m / s, 8 m / s, 9 m / s, 10 m / s, 12 m / s, 14 m / s, 16 m / s or 18 m / s.

[0059] Methods of producing other materials

[0060] In various aspects, the present invention provides a method for producing a product. The method may include placing a starting material mixture into a starting material feed port in a reaction chamber of a vertical reactor. The vertical reactor may include a product outlet in the reaction chamber (e.g., at the bottom of the reaction chamber), a gaseous combustion mixture inlet into the reaction chamber, and one or more exhaust ports in the reaction chamber (e.g., at the top of the reaction chamber). The method may include placing a gaseous combustion mixture into a gaseous combustion mixture inlet. The method may include burning a gaseous combustion mixture in a vertical reactor to heat the starting material mixture and form a product therefrom. The method may also include removing the product from the product outlet.

[0061] The method can be a method for cement production (e.g., producing clinker from a preclinker mix as described above), or a method for calcining a source of CaO (e.g., CaCO3 or any source of CaO described herein) to produce lime, calcining to desorb CO2 from any carbonate rock (e.g., limestone) in a direct air capture system, sintering refractory materials, producing lithium via spodumene, or direct reduced iron processing.

[0062] equipment

[0063] Various aspects of the present invention provide an apparatus for performing the method of the present invention. The apparatus may be any suitable apparatus capable of performing the method. For example, the apparatus may include a vertically oriented reaction chamber. The apparatus may include a starting material feed port in the reaction chamber. The starting material feed port may be located at the top of the reaction chamber, or in another suitable part of the reaction chamber. The apparatus may include a gaseous combustion mixture inlet for entering the reaction chamber into which the gaseous combustion mixture is injected.

[0064] The apparatus may be an apparatus for producing clinker from a preclinker mixture, wherein the apparatus is configured to combust a gaseous combustion mixture in a vertical reactor to heat the preclinker mixture, release CO2 therefrom, and form clinker therefrom. The apparatus may be an apparatus for calcining a source of CaO (e.g., CaCO3) to produce lime, calcining to desorb CO2 from carbonates (e.g., limestone) in a direct air capture system, sintering refractory materials, producing lithium from spodumene, or direct reduced iron processing.

[0065] Figure 2 An apparatus for producing clinker according to various aspects is shown.

[0066] Example

[0067] Various embodiments of the invention may be better understood by reference to the following examples which are provided by way of illustration.The invention is not limited to the examples given herein.

[0068] Example 1. Bench-scale reactor

[0069] A bench-scale reactor with subadiabatic filtered combustion using methane as fuel and air as oxidant was used. Figure 2 The design shown in .

[0070] During the test, a maximum temperature of 1568°C was achieved. X-ray diffraction (XRD) analysis was performed on the product to confirm that the commercial quality clinker produced was comparable to that produced by conventional rotary kilns. Table 1 illustrates the phase distribution of the clinker produced.

[0071] Table 1. Phase distribution of clinker. OPC refers to Ordinary Portland Cement.

[0072] Mutually Typical Type I / II OPC clinker Example 1 Clinker C3S 50% to 70% 67％ C2S 10% to 25% 9.3％ C3A <10％ 3.3％ C4AF <15％ 10.4％

[0073] Example 2. Efficiency simulation

[0074] Based on both the bench-scale testing performed in Example 1 and other laboratory-scale testing that has been performed, Figure 2 The efficiency of the reactor shown in is estimated.

[0075] like Figure 3 As shown in the diagram of , the premixed fuel-air mixture enters the reaction chamber filled with porous media and is preheated until it reaches its ignition temperature. Q_in, the energy of the incoming fuel mixture, is equal to Q_utilized + Q_surface + Q_out, where Q_surface is the energy lost to the environment from the surface of the reactor, Q_out is the energy lost to the environment through heat removal, and Q_utilized is the energy consumed by the clinkering reaction. The efficiency is equal to Q_utilized / Q_in. The following assumptions are made in the simulation: (1) The thermodynamic properties of the fuel-air mixture and the combustion products are functions of temperature and concentration; (2) There is thermal equilibrium between the gas phase and the solid phase; (3) The pressure drop on both sides of the flame is negligible; (4) The particles comprising the porous media are uniformly distributed; (5) The flow is one-dimensional and incompressible; (6) The gas radiation is negligible compared to the solid radiation; (7) The particles comprising the porous media are non-catalytic. Figure 4 The efficiency at a constant fuel / air equivalence ratio of 0.7 is shown versus V_inlet, which is the velocity of the gas relative to the walls of the reactor. V_inlet is proportional to the total volume of gas divided by the cross-sectional area of ​​the reactor. The estimated efficiency is approximately 82% to 83.5%. Figure 5 The efficiency and equivalence ratio at a constant V_inlet of 0.5 m / s are shown, with a predicted efficiency of about 68% to 86%.

[0076] The terms and expressions used are used as descriptive terms rather than limiting terms, and the use of such terms and expressions is not intended to exclude any equivalents of the features shown and described or parts thereof, but it should be recognized that various modifications may be made within the scope of the various aspects of the present invention. Therefore, it should be understood that although the present invention has been specifically disclosed through specific aspects and optional features, modifications and variations of the concepts disclosed herein may be adopted by those of ordinary skill in the art, and such modifications and variations are considered to be within the scope of the various aspects of the present invention.

[0077] Exemplary Aspects

[0078] The following exemplary aspects are provided, the numbering of which is not to be construed as designating a level of importance:

[0079] Aspect 1 provides a method for producing clinker, the method comprising:

[0080] A preclinker mixture including a source of CaO (e.g., wherein the source of CaO includes CaCO3) is placed into a starting material feed port in a vertically oriented reaction chamber of a vertical reactor (e.g., at the top of the reaction chamber of the vertical reactor), wherein the vertical reactor includes:

[0081] a product outlet in the reaction chamber (e.g., at the bottom of the reaction chamber),

[0082] an inlet for the gaseous combustion mixture into the reaction chamber, and

[0083] one or more exhaust ports in the reaction chamber (e.g., at the top of the reaction chamber);

[0084] placing a gaseous combustion mixture into a gaseous combustion mixture inlet;

[0085] burning the gaseous combustion mixture in a vertical reactor to heat the preclinker mixture, release CO2 therefrom, and form clinker therefrom;

[0086] The clinker is removed from the product outlet.

[0087] Aspect 2 provides the method of aspect 1, wherein the method does not involve applying external heat to the reaction chamber.

[0088] Aspect 3 provides the method of any of aspects 1 to 2, wherein the combustion of the gaseous combustion mixture is superadiabatic combustion, and wherein the superadiabatic combustion is self-sustaining (ie, no external heat is applied to the reaction chamber).

[0089] Aspect 4 provides the method of any one of aspects 1 to 3, wherein the combustion occurs on and / or in the preclinker mixture.

[0090] Aspect 5 provides the method of any one of aspects 1 to 4, wherein the combustion of the gaseous combustion mixture is non-superadiabatic combustion, and wherein the non-superadiabatic combustion is self-sustaining (ie, no external heat is applied to the reaction chamber).

[0091] Aspect 6 provides the method described in any one of Aspects 1 to 5, wherein the preclinker mixture further includes SiO2, Al2O3, Fe2O3, SO3, MgO, P2O5 or a combination thereof.

[0092] Aspect 7 provides the method of any one of aspects 1 to 6, wherein the gaseous combustion mixture comprises C1-C5 hydrocarbons, H2, O2, N2, CO2, CO, or a combination thereof.

[0093] Aspect 8 provides the method of aspect 7, wherein the gaseous combustion mixture comprises N2, CO2, O2, or a combination thereof.

[0094] Aspect 9 provides the method of any one of aspects 1 to 8, wherein the gaseous combustion mixture comprises biogas, syngas, or a combination thereof.

[0095] Aspect 10 provides the method of any one of aspects 1 to 9, wherein the gaseous combustion mixture comprises air, oxygen-enriched air, synthetic air, oxygen-depleted synthetic air, oxygen-enriched synthetic air, or a combination thereof.

[0096] Aspect 11 provides the method of any one of aspects 1 to 10, wherein the preclinker mixture is particulate and comprises a maximum dimension of about 1 mm to about 50 mm.

[0097] Aspect 12 provides the method of any aspect 11, wherein the preclinker mixture comprises a maximum dimension of about 3 mm to about 15 mm.

[0098] Aspect 13 provides the method of any one of aspects 1 to 12, wherein the preclinker mixture in the reaction chamber is preheated by heat from gaseous products produced by combustion in a lower portion of the reaction chamber.

[0099] Aspect 14 provides the method of aspect 13, wherein preheating is provided without applying any external heat source.

[0100] Aspect 15 provides the method of any one of aspects 1 to 14, wherein forming clinker from the preclinker mixture includes forming CaO from a source of CaCO3 (e.g., limestone (e.g., inorganic or fossiliferous sedimentary limestone, metamorphic rock, and igneous carbonate rock), calcium silicate minerals (e.g., wollastonite), and / or calcium aluminosilicates (e.g., slag or anorthite). Forming CaO from a source of CaO may include forming a calcined intermediate product prior to forming the clinker.

[0101] Aspect 16 provides a method described in any one of Aspects 1 to 15, wherein forming clinker from the preclinker mixture includes: forming 2CaO·SiO2, 3CaO·SiO2, 3CaO·Al2O3, 4CaO·Al2O3·Fe2O3, CaO·Al2O3, 12CaO7·Al2O3, 2CaO·Al2O3, 4CaO3·Al2O3SO3 or a combination thereof.

[0102] Aspect 17 provides the method of any one of aspects 1 to 16, wherein forming clinker from the preclinker mixture comprises calcining, clinkerizing, sintering, or a combination thereof.

[0103] Aspect 18 provides the method of any one of aspects 1 to 17, wherein the gas combustion mixture cools the clinker at the bottom of the vertical reactor before the clinker is removed from the product outlet.

[0104] Aspect 19 provides the method of aspect 18, wherein cooling the clinker comprises: absorbing heat from the clinker by the pre-clinker mixture.

[0105] Aspect 20 provides the method of any of aspects 1 to 19, wherein heating the preclinker mixture to form clinker therefrom comprises heating the preclinker mixture to a temperature of 1472°F (800°C) to 3632°F (2000°C).

[0106] Aspect 21 provides the method of any of aspects 1 to 20, wherein heating the preclinker mixture to form clinker therefrom comprises heating the preclinker mixture to a temperature of 2282°F (1250°C) to 2732°F (1500°C).

[0107] Aspect 22 provides the method of any of aspects 1 to 21, wherein the reaction chamber comprises a single combustion wave.

[0108] Aspect 23 provides the method of aspect 22, wherein the reaction chamber has no more than a single combustion wave.

[0109] Aspect 24 provides the method of any one of aspects 1 to 21, wherein the reaction chamber comprises two or more combustion waves.

[0110] Aspect 25 provides the method of any one of Aspects 1 to 24, wherein the reaction chamber comprises two combustion waves, wherein the first combustion wave comprises a calcining zone, and wherein the second combustion wave comprises a clinkering zone, wherein the second combustion wave is below the first combustion wave.

[0111] Aspect 26 provides the method of any one of aspects 1 to 25, wherein the reaction chamber comprises a plurality of gaseous combustion mixture inlets, wherein the method comprises injecting the gaseous combustion mixture into each gaseous combustion mixture inlet.

[0112] Aspect 27 provides the method of any one of aspects 1 to 26, comprising operating the vertical reactor in batch mode.

[0113] Aspect 28 provides the method of any one of aspects 1 to 26, comprising operating the vertical reactor in a continuous mode.

[0114] Aspect 29 provides a method for producing a product, the method comprising:

[0115] The starting material mixture is placed into a starting material feed port (e.g., at the top of the reaction chamber) in a vertically oriented reaction chamber of a vertical reactor, wherein the vertical reactor comprises:

[0116] a product outlet in the reaction chamber (e.g., at the bottom of the reaction chamber),

[0117] an inlet for the gaseous combustion mixture into the reaction chamber, and

[0118] one or more exhaust ports in the reaction chamber (e.g., at the top of the reaction chamber);

[0119] placing a gaseous combustion mixture into a gaseous combustion mixture inlet;

[0120] combusting the gaseous combustion mixture in a vertical reactor to heat the starting material mixture and form products therefrom;

[0121] The product is removed from the product outlet.

[0122] Aspect 30 provides the method described in Aspect 29, wherein the method is a method for cement production, calcining a source of CaO (e.g., CaCO3) to produce lime, calcining to desorb CO2 from carbonates (e.g., limestone) in a direct air capture system, sintering refractory materials, producing lithium via spodumene, or direct reduced iron processing.

[0123] Aspect 31 provides a device, comprising:

[0124] a vertically oriented reaction chamber;

[0125] a starting material feed port in the reaction chamber (e.g., at the top of the reaction chamber); and

[0126] A gaseous combustion mixture inlet is provided into the reaction chamber for injecting the gaseous combustion mixture therein.

[0127] Aspect 32 provides the apparatus of aspect 31, wherein the apparatus further comprises one or more exhaust ports at the top of the reaction chamber.

[0128] Aspect 33 provides the apparatus described in any one of Aspects 31 to 32, wherein the apparatus is used to produce clinker, wherein the apparatus is configured to combust the gaseous combustion mixture in a vertical reactor to heat the pre-clinker mixture, release CO2 therefrom, and form clinker therefrom.

[0129] Aspect 34 provides a method or apparatus according to any one or any combination of aspects 1 to 33, optionally configured so that all elements or options described may be used or selected.

Claims

1. A method for producing clinker, the method comprising: A preclinker mixture including a source of CaO is placed into a starting material feed port in a vertical reactor, wherein the vertical reactor comprises: a vertically oriented longitudinal axis of the reaction chamber, Export of products, an inlet for the gaseous combustion mixture into the reaction chamber, and one or more exhaust ports; placing a gaseous combustion mixture into the gaseous combustion mixture inlet; combusting the gaseous combustion mixture in the vertical reactor to heat the preclinker mixture, release CO2 therefrom, and form the clinker therefrom; and The clinker is removed from the product outlet.

2. The method according to claim 1, wherein: The vertically oriented longitudinal axis of the reaction chamber forms an angle of 45° to 90° with the horizontal axis.

3. The method according to claim 1, wherein: The starting material feed port is located at the top of the reaction chamber, the one or more exhaust ports are located at the top of the reaction chamber, and wherein the product outlet is located at the bottom of the reaction chamber.

4. The method according to claim 1, wherein: The sources of CaO include CaCO3, limestone, calcium silicate minerals and / or calcium aluminosilicate.

5. The method according to claim 1, wherein: The preclinker mixture also includes SiO2, Al2O3, Fe2O3, SO3, MgO, P2O5 or a combination thereof.

6. The method according to claim 1, wherein: The gaseous combustion mixture includes C1-C5 hydrocarbons, H2, O2, N2, CO2, CO, oxygen-enriched air, synthetic air, oxygen-depleted synthetic air, oxygen-enriched synthetic air, biogas, synthesis gas, or a combination thereof.

7. The method according to claim 1, wherein: The preclinker mixture is in the form of particles, granules, and / or agglomerates and includes a maximum dimension of about 1 mm to about 50 mm.

8. The method according to claim 1, wherein: The preclinker mixture in the reaction chamber is preheated by heat from gaseous products of combustion in the lower part of the reaction chamber.

9. The method according to claim 1, wherein: Forming the clinker from the pre-clinker mix comprises forming CaO from a source of CaO.

10. The method according to claim 1, wherein: Forming the clinker from the pre-clinker mixture includes: forming 2CaO·SiO2, 3CaO·SiO2, 3CaO·Al2O3, 4CaO·Al2O3·Fe2O3, CaO·Al2O3, 12CaO7·Al2O3, 2CaO·Al2O3, 4CaO3·Al2O3SO3 or a combination thereof.

11. The method according to claim 1, wherein: The gaseous combustion mixture cools the clinker before the clinker is removed from the product outlet.

12. The method according to claim 1, wherein: Heating the preclinker mixture to form the clinker therefrom includes heating the preclinker mixture to a temperature of 1472°F (800°C) to 3632°F (2000°C).

13. The method according to claim 1, wherein: Heating the preclinker mixture to form the clinker therefrom includes heating the preclinker mixture to a temperature of 2282°F (1250°C) to 2732°F (1500°C).

14. The method according to claim 1, wherein: The reaction chamber includes a single combustion wave.

15. The method according to claim 1, wherein: The reaction chamber includes two or more combustion waves.

16. The method according to claim 1, wherein: The reaction chamber comprises a plurality of gaseous combustion mixture inlets, wherein the method comprises injecting the gaseous combustion mixture into each gaseous combustion mixture inlet.

17. A method for producing a product, the method comprising: The starting material mixture is placed into a starting material feed port in a reaction chamber of a vertical reactor, wherein the vertical reactor comprises: a vertically oriented longitudinal axis of the reaction chamber, a product outlet in the reaction chamber, an inlet for the gaseous combustion mixture into the reaction chamber, and one or more exhaust ports in the reaction chamber; placing a gaseous combustion mixture into the gaseous combustion mixture inlet; combusting the gaseous combustion mixture within the vertical reactor to heat the starting material mixture and form the product therefrom; and The product is removed from the product outlet.

18. The method according to claim 17, wherein: The process is a process for cement production, calcining a source of CaO (e.g., CaCO3) to produce lime, calcining to desorb CO2 from carbonates in direct air capture systems, sintering refractory materials, producing lithium via spodumene, or direct reduced iron processing.

19. A device comprising: a reaction chamber including a vertically oriented longitudinal axis; Starting material feed port; as well as A gaseous combustion mixture inlet is provided into the reaction chamber for injecting a gaseous combustion mixture therein.

20. The apparatus of claim 19, wherein: The apparatus is configured to combust the gaseous combustion mixture in the presence of a pre-clinker mixture to form clinker in the absence of any added inert burner medium.

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