Low-temperature calcium carbonate catalytic decomposition method and system

Abstract

The invention discloses a low-temperature calcium carbonate catalytic decomposition method and system, and relates to the technical field of cement production, the system comprises a pyrolysis subsystem, a phase change heat storage subsystem, a cyclone separation system, a cooling dust removal subsystem and a storage tank subsystem, the pyrolysis subsystem comprises a coupling electrolytic furnace and a control system, the control system is used for controlling the reaction of the coupling electrolytic furnace; the phase change heat storage subsystem is used for providing a heat source for the reaction of the pyrolysis subsystem; a first air inlet of the first-stage cyclone separator is communicated with the top of the coupling electrolytic furnace through a first connecting pipe, and a first air outlet of the first-stage cyclone separator is communicated with a second air inlet of the second-stage cyclone separator through a second connecting pipe; one end of the cooling dust removal subsystem is communicated with a second air outlet of the secondary cyclone separator; and the storage tank subsystem is connected to the other end of the cooling dust removal subsystem. According to the cement production system for producing synthesis gas based on carbonate hydrogenation coupling, energy-saving production of cement is realized by selecting heat storage particles for heat supply and methanol as reaction gas.

Description

Technical Field

[0001] The invention relates to the technical field of cement clinker production, and in particular to a low-temperature calcium carbonate catalytic decomposition method and system. Background Art

[0002] In recent years, experimental studies have found that the main gas product of the hydrogenation pyrolysis reaction of carbonates such as limestone and magnesium carbonate in a hydrogen supply gas atmosphere such as H2 and CH4 is not CO2, but a synthesis gas of CO and CH4. Limestone hydrogenation has great emission reduction potential, but limestone decomposition is a strong endothermic reaction. In traditional industries, it is mainly heated by coal powder combustion.

[0003] Currently, H2 and CH4 are mainly used as hydrogen supply gases. However, in industrial applications, there are serious safety hazards due to airtightness issues. In addition, unreacted gases are difficult to separate, which affects the concentration of gas products.

[0004] In addition, some of the patents select methanol as the hydrogen donor molecule.

[0005] Methanol not only has the hydrogen supply effect of H2, CH4, etc., but also has a series of advantages such as better safety, lower transportation and storage costs, and easy separation.

[0006] The Chinese invention patent with application number 202210038687.2 discloses a multi-combustion mode ammonia fuel engine and its control method, which introduces a technical solution of using an ignition agent for the pre-combustion chamber and ammonia for the main combustion chamber. However, this solution requires the replenishment and storage of at least two types of fuel, which significantly complicates the system. Summary of the invention

[0007] In view of this, the present invention provides a low-temperature calcium carbonate catalytic decomposition method and system to solve the technical problems of safety, cost and gas separation difficulty of the limestone hydrogenation supporting industrial process in the existing cement clinker production process, so as to achieve energy-saving cement production.

[0008] To solve the above problems, the first object of the present invention is to provide a low-temperature calcium carbonate catalytic decomposition system, comprising:

[0009] The pyrolysis subsystem includes a coupled electrolytic furnace and a control system, wherein methanol vapor, cement raw material and catalyst are added to the coupled electrolytic furnace, and the control system is used to control the chemical reaction of the coupled electrolytic furnace;

[0010] A phase change heat storage subsystem, which is arranged on one side of the pyrolysis subsystem and is used to provide a heat source for the reaction of the pyrolysis subsystem;

[0011] The cyclone separation system comprises a primary cyclone separator, a secondary cyclone separator and a connecting pipe, wherein the first air inlet of the primary cyclone separator is connected to the top of the coupled electrolytic furnace through the first connecting pipe, and the first air outlet of the primary cyclone separator is connected to the second air inlet of the secondary cyclone separator through the second connecting pipe.

[0012] A cooling and dust removal subsystem, one end of which is connected to the second air outlet of the secondary cyclone separator through a third connecting pipe;

[0013] The storage tank subsystem is connected to the other end of the cooling and dust removal subsystem.

[0014] As a further improvement of the above technical solution, it also includes a return material subsystem, the top end of which is connected to the first discharge port of the primary cyclone separator, and the bottom end of which is connected to the return material feed port of the bottom pyrolysis furnace.

[0015] As a further improvement of the above technical solution, the coupled electrolytic furnace comprises a bottom pyrolysis furnace and a top pyrolysis furnace connected in parallel up and down, wherein:

[0016] The bottom pyrolysis furnace comprises a bottom pyrolysis furnace body and a bottom shell installed on the outer periphery of the bottom pyrolysis furnace, and a first gas air inlet and a return feeder feed port are provided at the bottom of the bottom pyrolysis furnace body;

[0017] The top pyrolysis furnace also includes a top pyrolysis furnace body and a top shell installed on the outer periphery of the top pyrolysis furnace body, and the bottom of the top pyrolysis furnace body is connected to the top opening of the bottom pyrolysis furnace body, and a second gas inlet is also opened on one side, and a synthesis gas outlet is opened on the top of the top pyrolysis furnace body.

[0018] As a further improvement of the above technical solution, the pyrolysis subsystem also includes a preheating furnace installed at the bottom of the bottom pyrolysis furnace, a preheating port is provided on one side of the top of the preheating furnace, a hydrogen supply port for connecting with the hydrogen supply gas is provided at the bottom of the preheating furnace, and a heat storage particle inlet is provided on the side wall of the preheating furnace close to the phase change heat storage subsystem.

[0019] As a further improvement of the above technical solution, the phase change heat storage subsystem includes a storage tank and a heat storage particle flow pipe, a heating device and a second heat insulation layer located in the storage tank, the first inlet of the heat storage particle flow pipe passes through the top wall of the storage tank and is connected to the feed port of the return feeder of the bottom pyrolysis furnace, and the first outlet of the heat storage particle flow pipe passes through the side wall of the storage tank and is connected to the heat storage particle inlet of the preheating furnace; the second heat insulation layer is suitable for filling the internal space between the storage tank and the heat storage particle flow pipe;

[0020] Heat storage particles are placed in the heat storage particle flow pipe, and the heating device is suitable for heating the heat storage particles.

[0021] As a further improvement of the above technical solution, the cooling and dust removal subsystem includes a water-cooling chamber and a serpentine tube located in the water-cooling chamber, a first air inlet of the serpentine tube passes through a top side wall of the water-cooling chamber and is connected to a second air outlet of the secondary cyclone separator, and a first air outlet of the serpentine tube passes through a bottom side wall of the water-cooling chamber and is connected to the storage tank subsystem;

[0022] The water cooling chamber is also provided with a first cooling water inlet and a first cooling water outlet, respectively. The first cooling water inlet is located on the bottom wall of the water cooling chamber, and the first cooling water outlet is located on the side wall of the water cooling chamber away from the first air inlet.

[0023] As a further improvement of the above technical solution, the heating device is an electric heating tube.

[0024] As a further improvement of the above technical solution, the return material subsystem includes a return material and an air distribution plate arranged on the inner bottom of the return material, a vertically arranged return material feed port and an inverted and inclined return material outlet port are provided on one side of the top of the return material, a return material replenishment port is provided on the return material near the air distribution plate, and a return material air inlet is provided on the bottom of the return material facing the return material feed port and the return material outlet port.

[0025] As a further improvement of the above technical solution, the heat storage particles include an Al2O3 packaging shell and a core-shell heat storage capsule arranged in the Al2O3 packaging shell, and an Al-based alloy is arranged inside the core-shell heat storage capsule.

[0026] The second object of the present invention is to provide a low-temperature calcium carbonate catalytic decomposition method, using the above-mentioned catalytic decomposition system, the catalytic decomposition method comprises the steps of:

[0027] Step S 100 : Methanol vapor is introduced into the coupled electrolytic furnace, and the methanol vapor is fully mixed and reacted with the cement raw material and the catalyst under the action of the control system, thereby decomposing the carbonate in the raw material into a solid product of calcium oxide and a mixed gas of CO and CH4;

[0028] Step S 200 : The phase change heat storage subsystem heats the low-temperature heat storage particles into high-temperature heat storage particles, and the high-temperature heat storage particles enter the pyrolysis subsystem to provide heat source for the reaction;

[0029] Step S 300: The mixed gas of solid product calcium oxide and CO, CH4 enters the cyclone separation system through the connecting pipe, and the synthesis gas and solid product are gradually separated in the primary cyclone separator and the secondary cyclone separator. The synthesis gas is transported out of the separation system and enters the cooling and dust removal subsystem, and the solid product enters the rotary kiln through the discharge pipe of the cyclone separation system;

[0030] Step S 400 : Filter the dust in the synthetic gas under the action of the cooling and dust removal subsystem;

[0031] Step S 500 : The filtered and cooled gas flows into the storage tank subsystem, and the unreacted methanol vapor is condensed into liquid through the cooling and dust removal subsystem, and is collected and reused.

[0032] Compared with the prior art, the present invention has significant advantages and beneficial effects, which are specifically embodied in the following aspects:

[0033] The low-temperature calcium carbonate catalytic decomposition system of the present invention is composed of a pyrolysis subsystem, a phase change heat storage subsystem, a cyclone separation system, a cooling and dust removal subsystem and a storage tank subsystem. In the catalytic decomposition system, methanol vapor is fully mixed with cement raw materials and catalysts in the pyrolysis subsystem, thereby decomposing carbonates in the raw materials into solid products of calcium oxide and a mixed gas of CO and CH4, thereby reducing CO2 emissions; the phase change heat storage subsystem heats the low-temperature heat storage particles into high-temperature heat storage particles, and the high-temperature heat storage particles enter the heating furnace in the pyrolysis subsystem to provide a heat source for the reaction. The gas products in the carbonate decomposition process are converted from CO2 to CO and CH4, which reduces CO2 emissions from the perspective of chemical reaction mechanism. In addition, the use of methanol as a hydrogen raw material is conducive to ensuring safety and reducing costs. The heat storage system and heat storage particles in the phase change heat storage subsystem provide the necessary heat for the reaction. The cyclone separation system consists of a first-stage cyclone separator and a second-stage cyclone separator. The two-stage cyclone system allows the synthesis gas to be fully separated from the solid (quicklime, catalyst and heat storage particles). This system provides a new technical solution for the low-carbon transformation of traditional industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of the structure of a low-temperature calcium carbonate catalytic decomposition system in an embodiment of the present invention;

[0035] Figure 2 Schematic diagram of the internal structure of the coupled electrolytic furnace in an embodiment of the present invention;

[0036] Figure 3 It is a schematic diagram of the connection structure of the cyclone separation system, the coupled electrolytic furnace and the cooling and dust removal subsystem in an embodiment of the present invention;

[0037] Figure 4This is a schematic structural diagram of a primary cyclone separator in an embodiment of the present invention;

[0038] Figure 5 It is a schematic diagram of the structure of the phase change heat storage subsystem in an embodiment of the present invention;

[0039] Figure 6 A schematic diagram of the structure of a cooling and dust removal subsystem in an embodiment of the present invention;

[0040] Figure 7 Schematic diagram of the structure of the material return subsystem in an embodiment of the present invention.

[0041] Description of reference numerals:

[0042] 1- Pyrolysis subsystem;

[0043] 11-preheating furnace; 111-preheating port; 112-hydrogen supply port; 113-heat storage particle inlet;

[0044] 12-coupled electrolytic furnace;

[0045] 121- bottom pyrolysis furnace; 1211- bottom pyrolysis furnace body; 1212- bottom shell; 1213- first gas air inlet; 1214- feed inlet of return feeder;

[0046] 122-top pyrolysis furnace; 1221-top pyrolysis furnace body; 1222-top shell; 1223-second gas air inlet; 1224-synthesis gas air outlet;

[0047] 123- first insulation layer;

[0048] 13- Control system;

[0049] 2- Cyclone separation system;

[0050] 21-first cyclone separator; 211-first separation cylinder; 2111-first discharge port; 2112-ash poking hole; 212-first air outlet; 213-first air inlet;

[0051] 22-secondary cyclone separator; 221-second air outlet; 222-second air inlet; 223-second material discharge port;

[0052] 23-connecting pipe; 231-first connecting pipe; 232-second connecting pipe; 233-third connecting pipe;

[0053] 3-Phase change heat storage subsystem;

[0054] 31-storage tank; 311-check valve; 312-base;

[0055] 32-heat storage particle flow pipe; 321-first inlet; 322-first outlet;

[0056] 33-heating equipment; 331-electric heating tube;

[0057] 34- second thermal insulation layer;

[0058] 4-Cooling and dust removal subsystem;

[0059] 41- water cooling chamber; 411- first cooling water inlet; 412- first cooling water outlet;

[0060] 42-serpentine tube; 421-first air inlet; 422-first air outlet;

[0061] 5-Storage tank subsystem;

[0062] 6-Return material subsystem;

[0063] 61-returning device; 611-returning device air inlet; 612-returning device feeding port; 613-returning device feeding pipe; 614-returning device discharging pipe;

[0064] 62- Wind distribution board. DETAILED DESCRIPTION

[0065] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0066] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0067] In the description of the present invention, if there are words such as "several", it means one or more, "more" means more than two, greater than, less than, exceed, etc. are understood as not including the number, and above, below, within, etc. are understood as including the number.

[0068] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0069] In the absence of conflict, the above embodiments and features in the embodiments may be combined with each other.

[0070] In the existing technology, cement clinker processing is an important part of the cement industry, and cement clinker is generally made from cement raw materials. For example, the main components of cement raw materials are limestone, MgCO3, SiO2, Al2O3, etc. After high-temperature reaction, carbonates are decomposed to burn into clinker. In this process, carbonates such as limestone and magnesium carbonate are decomposed by heat, and coal powder is used for heating, which produces a large amount of CO2 emissions.

[0071] In addition, there is a large amount of energy waste in the cement clinker synthesis process, accompanied by a series of problems such as incomplete reaction of raw materials, incomplete utilization of reaction heat, and insufficient utilization of reaction waste gas. Therefore, reducing energy waste in this process, coordinating resource utilization, and rationally utilizing waste gas are of great significance to energy conservation and emission reduction.

[0072] like Figure 1-7 As shown, an embodiment of the present invention provides a low-temperature calcium carbonate catalytic decomposition system, which includes a pyrolysis subsystem 1, a phase change heat storage subsystem 3, a cyclone separation system 2, a cooling and dust removal subsystem 4 and a storage tank subsystem 5, wherein:

[0073] The pyrolysis subsystem 1 includes a coupled electrolytic furnace 12 and a control system 13. Cement raw materials and catalysts are added to the coupled electrolytic furnace 12. The control system 13 is used to control the reaction of the coupled electrolytic furnace 12. The air outlet pipe at the upper end of the pyrolysis furnace contains solid products, synthesis gas and catalyst particles.

[0074] The phase change heat storage subsystem 3 is arranged on one side of the pyrolysis subsystem 1 and is used to provide a heat source for the reaction of the pyrolysis subsystem 1;

[0075] The cyclone separation system 2 includes a primary cyclone separator 21, a secondary cyclone separator 22 and a connecting pipe 23. The primary cyclone separator 21 is used to separate the catalyst, iron particles from the synthesis gas and solid products, and the secondary cyclone separator 22 is similar to the primary cyclone separator 21, except that the first connecting pipe 231 is connected to the primary cyclone separator 21, and the secondary cyclone separator 22 is connected to the primary cyclone separator 21 through the second connecting pipe 232. At this time, the solid product in the cylinder is separated from the synthesis gas, and the synthesis gas enters the cooling and dust removal subsystem 4 through the third connecting pipe 233, and the solid product enters the rotary kiln through the second discharge port 223.

[0076] Preferably, the first-stage cyclone separator 21 in this embodiment is composed of a first separation cylinder 211, and a first air outlet 212 is provided on the top of the first separation cylinder 211 for conveying solid products and synthesis gas into the second-stage cyclone separator 22 for further separation; a first air inlet 213 is provided on the upper side wall of the first separation cylinder 211 for receiving solid products, synthesis gas and catalyst particles flowing into the coupled electrolytic furnace 12; an ash poking hole 2112 is also provided on the bottom side wall of the first separation cylinder 211, and the ash poking hole 2112 plays a role in smooth material discharge and airtight air locking.

[0077] The first air inlet 213 of the primary cyclone separator 21 is connected to the top of the coupled electrolytic furnace 12 through the first connecting pipe 231, and the first air outlet 212 of the primary cyclone separator 21 is connected to the second air inlet 222 of the secondary cyclone separator 22 through the second connecting pipe 232. Under the action of the primary cyclone separator 21, the solid product and the synthesis gas enter the secondary cyclone separator 22 through the first air outlet 212 and the second connecting pipe 232. Under the action of the secondary cyclone separator 22, the solid product enters the rotary kiln through the second discharge port 223 of the secondary cyclone separator 22 for subsequent processing, and the synthesis gas flows into the cooling and dust removal subsystem 4 through the second air outlet 221 of the secondary cyclone separator 22 for dust removal.

[0078] One end of the cooling and dust removal subsystem 4 is in communication with the second air outlet 221 of the secondary cyclone separator 22;

[0079] The storage tank subsystem 5 is connected to the other end of the cooling and dust removal subsystem 4 , and the synthesis gas is cooled and dust removed by the cooling and dust removal subsystem 4 and then enters the storage tank subsystem 5 for storage.

[0080] Since limestone decomposition is a strong endothermic reaction, the heat of the reaction is mainly provided by the heat storage particles. Compared with other heat storage media, solid particles have high operating temperatures, simple conditions and low costs.

[0081] It should be noted that the hydrogen supply gas introduced into the pyrolysis subsystem 1 is methanol vapor. Compared with other hydrogen supply gases such as H2 and CH4, methanol has the advantages of strong safety and low transportation cost. In the methanol atmosphere, the product of limestone thermal decomposition is no longer CO2, but synthesis gas with CO and CH4 as the main components.

[0082] For further information, see Figure 1 , 4As shown in , 7, the low-temperature calcium carbonate catalytic decomposition system also includes a return material subsystem 6, the top of the return material subsystem 6 is connected to the first feed port 2111 of the primary cyclone separator 21, and the bottom of the return material subsystem 6 is connected to the return material feed port 1214 of the bottom pyrolysis furnace 121. In this way, the catalyst and heat storage particles in the primary cyclone separator 21 can be returned to the bottom pyrolysis furnace 121 through the return material subsystem 6.

[0083] For further information, see Figure 1 , 2 As shown, the coupled electrolytic furnace 12 includes a bottom pyrolysis furnace 121 and a top pyrolysis furnace 122 connected in parallel up and down, wherein:

[0084] The bottom pyrolysis furnace 121 includes a bottom pyrolysis furnace body 1211 and a bottom shell 1212. The bottom shell 1212 is installed on the outer periphery of the bottom pyrolysis furnace 121. The bottom of the bottom pyrolysis furnace body 1211 is provided with a first gas air inlet 1213 and a return feeder feed port 1214.

[0085] The top pyrolysis furnace 122 includes a top pyrolysis furnace body 1221 and a top outer shell 1222. The top outer shell 1222 is installed on the periphery of the top pyrolysis furnace body 1221, and the bottom of the top pyrolysis furnace body 1221 is connected to the top opening of the bottom pyrolysis furnace body 1211, and a second gas inlet 1223 is also opened on one side. A synthesis gas outlet 1224 is opened on the top of the top pyrolysis furnace body 1221, and solid products, synthesis gas and catalyst particles come out of the synthesis gas outlet 1224.

[0086] Specifically in the embodiment of the present invention, the coupled electrolytic furnace 12 is the main place for clinker synthesis. In the coupled electrolytic furnace 12, most of the carbonates are pyrolyzed into metal oxides and CO, CH4 synthesis gas under a hydrogen supply gas atmosphere, and the hydrogen supply gas can be hydrogen, methane, etc. The gas and solid are evenly mixed in the bottom pyrolysis furnace 121, and the heat of the reaction is provided by the frequency conversion coil.

[0087] The first gas inlet 1213 is the main way for the hydrogen supply gas to enter the pyrolysis furnace. Under the action of the lower fan, the hydrogen supply gas enters the pyrolysis furnace evenly and continuously to participate in the pyrolysis reaction; the return feed port 1214 is the main entry route for the catalyst, iron particles and heat storage particles to enter the bottom pyrolysis furnace 121, wherein the catalyst is mainly used to accelerate the reaction rate and improve the selectivity of the synthesis gas, the iron particles are mainly used for heat conduction to ensure uniform temperature in the pyrolysis furnace, and the heat storage particles mainly provide heat source for the reaction; the catalyst and iron particles entering the pyrolysis furnace mainly come from the first-stage cyclone separator 21 and the feed in the return subsystem 6, and the heat storage particles come from the storage tank 31.

[0088] Part of the hydrogen supply gas enters the top pyrolysis furnace 122 from the second gas inlet 1223 of the hydrogen supply gas, and is evenly mixed with the gas-solid products in the bottom pyrolysis furnace 121 at the bottom of the top pyrolysis furnace 122. The gas-solid products further react in the top pyrolysis furnace 122 at the upper layer, and finally enter the primary cyclone separator 21 from the synthesis gas outlet 1224.

[0089] In addition, a first thermal insulation layer 123 is provided inside the bottom pyrolysis furnace 121 and the top pyrolysis furnace 122 . The first thermal insulation layer 123 can optimize wall heat transfer so that the temperature inside the coupled electrolytic furnace 12 is uniform.

[0090] For further information, see Figure 1 As shown, the pyrolysis subsystem 1 also includes a preheating furnace 11, which is installed at the bottom of the bottom pyrolysis furnace 121, wherein a preheating port 111 is provided on one side of the top of the preheating furnace 11, a hydrogen supply port 112 for connecting to the hydrogen supply gas is provided at the bottom of the preheating furnace 11, and a heat storage particle inlet 113 is provided on the side wall of the preheating furnace 11 close to the phase change heat storage subsystem 3.

[0091] Specifically in the embodiment of the present invention, the preheated raw material is preheated from the preheating port 111 (i.e., the attached Figure 1 The left end of the preheating furnace 11 enters the preheating furnace 11, the predetermined temperature of the limestone is about 800 degrees, the catalyst enters the preheating furnace 11 from the right end through the return subsystem 6, and the hydrogen supply gas and high-temperature heat storage particles enter the preheating furnace 11 from the hydrogen supply port 112 of the preheating furnace 11 (located at the bottom of the preheating furnace 11).

[0092] For further information, see Figure 1 , 5 As shown, the phase change heat storage subsystem 3 includes a storage tank 31, a heat storage particle flow pipe 32, a heating device 33 and a second heat insulation layer 34. The heat storage particle flow pipe 32, the heating device 33 and the second heat insulation layer 34 are all located in the storage tank 31, and the first inlet 321 of the heat storage particle flow pipe 32 passes through the top wall of the storage tank 31 and is connected to the return feed port 1214 of the bottom pyrolysis furnace 121, and the first outlet 322 of the heat storage particle flow pipe 32 passes through the side wall of the storage tank 31 and is connected to the heat storage particle inlet 113 of the preheating furnace 11. In actual operation, the heat storage particles are moved along the heat storage particle flow pipe 31. From the first inlet 321 to the first outlet 322, the material of the heat storage particle flow pipe 32 is mainly heat transfer material, and a transmission device is arranged in the heat storage particle flow pipe 32 to facilitate the particles to enter and exit the phase change heat storage subsystem 3; the second thermal insulation layer 34 is suitable for filling the internal space between the storage tank 31 and the heat storage particle flow pipe 32, mainly for heat preservation of the heat storage particles to avoid energy loss; the heat storage particles are placed in the heat storage particle flow pipe 32, the heating device 33 is suitable for heating the heat storage particles, and the second thermal insulation layer 34 can optimize the wall heat transfer to make the temperature in the reaction furnace uniform.

[0093] Specifically, the low-temperature heat storage particles in the primary cyclone separator 21 enter the heat storage particle flow pipe 32 inside the storage tank 31 from the first discharge port 2111 through the first inlet 321. Since the heating device 33 is arranged at the heat storage particle flow pipe 32, the low-temperature heat storage particles are heated by the heating device 33 and become high-temperature heat storage particles. Then, they enter the preheating furnace 11 from the first outlet 322 of the heat storage particle flow pipe 32 to provide heat for subsequent reactions in the preheating furnace 11.

[0094] Preferably, a check valve 311 and a base 312 are also provided on the storage tank 31, wherein the check valve 311 is located in the middle of the top of the storage tank 31 for inspection when a failure occurs in the phase change heat storage subsystem 3; the base 312 is symmetrically arranged at the bottom of the storage tank 31 for providing installation support for the storage tank 31.

[0095] Preferably, the heating device 33 may be an electric heating tube 331, through which

[0096] For further information, see Figure 1 , 6 As shown, the cooling and dust removal subsystem 4 includes a water cooling chamber 41 and a serpentine tube 42. The serpentine tube 42 is located in the water cooling chamber 41. The first air inlet 421 of the serpentine tube 42 passes through a top side wall of the water cooling chamber 41 and is connected to the second air outlet 221 of the secondary cyclone separator 22. The first air outlet 422 of the serpentine tube 42 passes through a bottom side wall of the water cooling chamber 41 and is connected to the storage tank subsystem 5.

[0097] The water cooling chamber 41 is further provided with a first cooling water inlet 411 and a first cooling water outlet 412 , wherein the first cooling water inlet 411 is located on the bottom wall of the water cooling chamber 41 , and the first cooling water outlet 412 is located on the side wall of the water cooling chamber 41 away from the first air inlet 421 .

[0098] Specifically in the embodiment of the present invention, the pipe opening of the cooling and dust removal subsystem 4 is provided with an ash filter device and an electrostatic dust removal device to ensure that the incoming synthesis gas is dust-free.

[0099] The cooling water is stored in the water cooling chamber 41. The cooling water enters the water cooling chamber 41 from the first cooling water inlet 411 and leaves the water cooling chamber 41 from the first cooling water outlet 412. The cooled synthesis gas leaves the cooling and dust removal subsystem 4 from the first cooling water outlet 412 and enters the gas storage tank for storage.

[0100] The synthesis gas at this time should mainly be a synthesis gas of CO and CH4, in which CO is the main component, and a small amount of CO2 and a very small amount of air may be mixed in the components, which has application value.

[0101] In addition, a dust filter is provided in the cooling and dust removal subsystem 4 to filter dust in the synthesis gas. The filtered and cooled gas enters the storage tank subsystem 5 through the air outlet pipe. The unreacted methanol vapor is condensed into liquid through the cooling and dust removal subsystem 4 and can be reused after being collected.

[0102] For further information, see Figure 1 , 7 As shown, the material return subsystem 6 includes a material return device 61 and an air distribution plate 62, wherein:

[0103] The air distribution plate 62 is arranged on the inner bottom of the return material 61, and a vertically arranged return material feed pipe 613 and an inverted and inclined return material discharge pipe 614 are provided on one side of the top of the return material 61. A return material replenishment port 612 is provided on the return material 61 near the air distribution plate 62, and a return material inlet 611 is provided on the bottom of the return material 61, facing the return material feed pipe 613 and the return material discharge pipe 614.

[0104] Specifically in the embodiment of the present invention, the returner 61 is mainly used to collect the separated catalyst and iron particles, and mix them with the supplemented catalyst and iron particles, and finally send them to the bottom pyrolysis furnace 121 in the coupled electrolytic furnace 12 for reuse. The returner feed pipe 613 is connected to the primary cyclone separator 21. After the catalyst and iron particles are separated by the primary cyclone separator 21, they enter the returner 61 through the returner feed pipe 613. The returner air inlet 611 is connected to the blower, and hydrogen supply gas is continuously blown into the returner 61 to ensure the fluidized state inside the returner 61; the returner feed port 612 is used to supplement the catalyst and iron particles into the returner 61 to ensure the smooth reaction. The air distribution plate 62 blows the mixed particles into the returner discharge pipe 614 by evenly distributing the air. The returner discharge pipe 614 is directly connected to the bottom pyrolysis furnace 121 to convey the mixed catalyst and iron particles.

[0105] Preferably, the returner 61 in the embodiment of the present invention is designed to be concave, wherein the air is evenly distributed below the returner 61, and a returner feeding port 612 is opened on the side to achieve the function of replenishing catalyst and iron powder.

[0106] Furthermore, the heat storage particles include an Al2O3 encapsulation shell and a core-shell heat storage capsule arranged in the Al2O3 encapsulation shell, and the interior of the core-shell heat storage capsule is provided with Al-based alloy.

[0107] The catalytic particles of the reaction are mainly Ni-based and Co-based catalysts, in addition to which some iron particles are added to achieve uniform heat transfer.

[0108] Another embodiment of the present invention provides a low-temperature calcium carbonate catalytic decomposition method, using the above-mentioned catalytic decomposition system, the catalytic decomposition method comprises the steps of:

[0109] Step S100 : Methanol vapor is introduced into the coupled electrolytic furnace 12, and the methanol vapor is fully mixed and reacted with the cement raw material and the catalyst under the action of the control system 13, thereby decomposing the carbonate in the raw material into a solid product of calcium oxide and a mixed gas of CO and CH4;

[0110] Step S 200 : The phase change heat storage subsystem 3 heats the low-temperature heat storage particles into high-temperature heat storage particles, and the high-temperature heat storage particles enter the pyrolysis subsystem 1 to provide a heat source for the reaction;

[0111] Step S 300 : The mixed gas of solid product calcium oxide and CO, CH4 enters the cyclone separation system 2 through the connecting pipe, and the synthesis gas and solid product are gradually separated in the primary cyclone separator 21 and the secondary cyclone separator 22. The synthesis gas is transported out of the separation system and enters the cooling and dust removal subsystem 4, and the solid product enters the rotary kiln through the discharge pipe of the cyclone separation system 2;

[0112] Step S 400 : Filtering dust in the synthetic gas under the action of the cooling and dust removal subsystem 4;

[0113] Step S 500 : The filtered and cooled gas flows into the storage tank subsystem 5, and the unreacted methanol vapor is condensed into liquid through the cooling and dust removal subsystem, and is collected and reused.

[0114] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A low-temperature calcium carbonate catalytic decomposition system, characterized in that: include: The pyrolysis subsystem includes a coupled electrolytic furnace and a control system, wherein methanol vapor, cement raw material and catalyst are added to the coupled electrolytic furnace, and the control system is used to control the chemical reaction of the coupled electrolytic furnace; A phase change heat storage subsystem, which is arranged on one side of the pyrolysis subsystem and is used to provide a heat source for the reaction of the pyrolysis subsystem; A cyclone separation system, comprising a primary cyclone separator, a secondary cyclone separator and a connecting pipe, wherein a first air inlet of the primary cyclone separator is connected to the top of the coupled electrolytic furnace through a first connecting pipe, and a first air outlet of the primary cyclone separator is connected to a second air inlet of the secondary cyclone separator through a second connecting pipe; A cooling and dust removal subsystem, one end of which is connected to the second air outlet of the secondary cyclone separator through a third connecting pipe; The storage tank subsystem is connected to the other end of the cooling and dust removal subsystem.

2. The low-temperature calcium carbonate catalytic decomposition system according to claim 1, characterized in that: The coupled electrolytic furnace comprises a bottom pyrolysis furnace and a top pyrolysis furnace connected in parallel up and down, wherein: The bottom pyrolysis furnace comprises a bottom pyrolysis furnace body and a bottom shell installed on the outer periphery of the bottom pyrolysis furnace, and a first gas air inlet and a return feeder feed port are provided at the bottom of the bottom pyrolysis furnace body; The top pyrolysis furnace also includes a top pyrolysis furnace body and a top shell installed on the outer periphery of the top pyrolysis furnace body, and the bottom of the top pyrolysis furnace body is connected to the top opening of the bottom pyrolysis furnace body, and a second gas inlet is also opened on one side, and a synthesis gas outlet is opened on the top of the top pyrolysis furnace body.

3. The low-temperature calcium carbonate catalytic decomposition system according to claim 2, characterized in that: It also includes a material return subsystem, the top end of which is connected to the first material discharge port of the primary cyclone separator, and the bottom end of which is connected to the material return device feed port of the bottom pyrolysis furnace.

4. The low-temperature calcium carbonate catalytic decomposition system according to claim 3, characterized in that: The pyrolysis subsystem also includes a preheating furnace installed at the bottom of the bottom pyrolysis furnace, a preheating port is provided on one side of the top of the preheating furnace, a hydrogen supply port for connecting with the hydrogen supply gas is provided at the bottom of the preheating furnace, and a heat storage particle inlet is provided on the side wall of the preheating furnace close to the phase change heat storage subsystem.

5. The low-temperature calcium carbonate catalytic decomposition system according to claim 4, characterized in that: The phase-change heat storage subsystem includes a storage tank and a heat storage particle flow pipe, a heating device and a second heat insulation layer located in the storage tank. The first inlet of the heat storage particle flow pipe passes through the top wall of the storage tank and is connected to the feed port of the return feeder of the bottom pyrolysis furnace. The first outlet of the heat storage particle flow pipe 32 passes through the side wall of the storage tank and is connected to the heat storage particle inlet of the preheating furnace. The second heat insulation layer is suitable for filling the internal space between the storage tank and the heat storage particle flow pipe. Heat storage particles are placed in the heat storage particle flow pipe, and the heating device is suitable for heating the heat storage particles.

6. The low-temperature calcium carbonate catalytic decomposition system according to claim 1, characterized in that: The cooling and dust removal subsystem includes a water-cooling chamber and a serpentine tube located in the water-cooling chamber, wherein a first air inlet of the serpentine tube passes through a top side wall of the water-cooling chamber and is connected to a second air outlet of the secondary cyclone separator, and a first air outlet of the serpentine tube passes through a bottom side wall of the water-cooling chamber and is connected to the storage tank subsystem; The water cooling chamber is also provided with a first cooling water inlet and a first cooling water outlet, respectively. The first cooling water inlet is located on the bottom wall of the water cooling chamber, and the first cooling water outlet is located on the side wall of the water cooling chamber away from the first air inlet.

7. The low-temperature calcium carbonate catalytic decomposition system according to claim 5, characterized in that: The heating device is an electric heating tube.

8. The low-temperature calcium carbonate catalytic decomposition system according to claim 3, characterized in that: The return material subsystem includes a return material returner and an air distribution plate arranged on the inner bottom of the return material returner, a vertically arranged return material returner feed pipe and an inverted and inclined return material returner discharge pipe are provided on one side of the top of the return material returner, a return material return material replenishment port is provided near the air distribution plate, and a return material return material air inlet is provided at the bottom of the return material returner facing the return material return material feed pipe and the return material discharge pipe.

9. The low-temperature calcium carbonate catalytic decomposition system according to claim 5, characterized in that: The heat storage particles include an Al2O3 encapsulation shell and a core-shell heat storage capsule arranged in the Al2O3 encapsulation shell, and an Al-based alloy is arranged inside the core-shell heat storage capsule.

10. A low-temperature calcium carbonate catalytic decomposition method, using the catalytic decomposition system according to any one of claims 1 to 9, characterized in that: The catalytic decomposition method comprises the steps of: Step S 100 : Methanol vapor is introduced into the coupled electrolytic furnace, and the methanol vapor is fully mixed and reacted with the cement raw material and the catalyst under the action of the control system, thereby decomposing the carbonate in the raw material into a solid product of calcium oxide and a mixed gas of CO and CH4; Step S 200 : The phase change heat storage subsystem heats the low-temperature heat storage particles into high-temperature heat storage particles, and the high-temperature heat storage particles enter the pyrolysis subsystem to provide heat source for the reaction; Step S 300 : The mixed gas of solid product calcium oxide and CO, CH4 enters the cyclone separation system through the connecting pipe, and the synthesis gas and solid product are gradually separated in the primary cyclone separator and the secondary cyclone separator. The synthesis gas is transported out of the separation system and enters the cooling and dust removal subsystem, and the solid product enters the rotary kiln through the discharge pipe of the cyclone separation system; Step S 400 : Filter the dust in the synthetic gas under the action of the cooling and dust removal subsystem; Step S 500 : The filtered and cooled gas flows into the storage tank subsystem, and the unreacted methanol vapor is condensed into liquid through the cooling and dust removal subsystem, and is collected and reused.

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