System and method for coupling cement production with methanol promoted decomposition to produce olefins

Abstract

The application discloses a system and method for coupling cement production and methanol to promote decomposition to produce olefins, which comprises a cement clinker production module, a methanol supply module, a hydrogen-oxygen preparation module and a chemical synthesis module. Through multi-module collaborative coupling, carbon resource high-value conversion is realized on the basis of cement production. Methanol is introduced as a reducing medium in the carbonate decomposition link of cement production, so that the carbon components in the carbonate decomposition products are directly converted into carbon-containing chemical raw material gas, without the need for an additional carbon capture process. The oxygen produced by the hydrogen-oxygen preparation module is used for cement calcination strengthening combustion, and the hydrogen is used for chemical synthesis, forming a material and energy recycling in the system. The application breaks through the end-of-pipe treatment idea of traditional cement production carbon emission reduction, realizes the source conversion of "process carbon emission" to "chemical raw material", greatly simplifies the process, reduces energy consumption, synchronously produces cement and high-value olefins, and has significant environmental and economic benefits.

Description

Technical Field

[0001] This invention relates to the interdisciplinary field of cement manufacturing and carbon resource chemical engineering, specifically to a system and method for coupling cement production with methanol-promoted decomposition to produce olefins. Background Technology

[0002] The cement industry is one of the world's leading sources of carbon dioxide emissions, with approximately 60% of its carbon emissions originating from limestone. Process emissions from decomposition () This part of the emissions is inevitable and cannot be fundamentally eliminated by improving energy efficiency or using alternative fuels.

[0003] Traditional carbon capture and storage (CCS) technology, while capable of reducing carbon emissions, suffers from high investment costs, high energy consumption, and a lack of economic viability, hindering large-scale commercial application. Carbon capture and utilization (CCU) technology, although capable of […], […]. It can be converted into chemicals, but often requires first treating the low concentrations in cement flue gas. The process of capturing, compressing, purifying, and then reducing and converting is complex and energy-intensive, resulting in poor overall economic efficiency.

[0004] Methanol, as an important C1 chemical platform molecule, can be used as a fuel and can also be used to produce syngas through reforming, cracking, and other reactions. This process then leads to the production of high-value chemicals such as olefins. The Fischer-Tropsch synthesis technology is a mature process for converting syngas into hydrocarbons, but its economic viability is highly dependent on the cost and purity of the syngas. Currently, there is no known technology that directly introduces methanol into the cement decomposition process, using a chemical reaction to convert the end products of limestone decomposition from... Switching to CO allows us to bypass energy-intensive processes. The capture process provides a systematic solution for directly obtaining high-value chemical raw materials. Meanwhile, existing cement carbon reduction technologies mostly focus on carbon reduction from single-product production, failing to achieve deep integration of cement production with high-value chemical product production, resulting in limited resource utilization efficiency and economic benefits. Summary of the Invention

[0005] In view of this, the present invention aims to overcome the shortcomings of the prior art and provide a system and method for cement production coupled with methanol-promoted decomposition to produce olefins. Through deep integration and reaction coupling of multiple units, it fundamentally changes the direction of carbon flow in cement production from a chemical reaction perspective, thus transforming "waste" into... "Transforming into "raw material CO" saves on high energy consumption The capture and conversion process simultaneously achieves stable production of cement clinker and efficient synthesis of low-carbon olefins, thus achieving a balance between carbon emission reduction and economic benefits.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0007] The first objective of this invention is to provide a system for cement production coupled with methanol-promoted decomposition to produce olefins, comprising:

[0008] The cement clinker production module is used to complete the preheating of raw materials, decomposition of carbonates, high-temperature calcination and cooling of clinker, and to produce cement clinker.

[0009] A methanol supply module is used to store methanol and supply methanol to the carbonate decomposition stage of the cement clinker production module, wherein the methanol participates in the carbonate decomposition reaction as a reducing medium.

[0010] The hydrogen and oxygen preparation module is used to generate hydrogen and oxygen. The oxygen is supplied to the calcination stage of the cement clinker production module, and the hydrogen is supplied to the chemical synthesis module.

[0011] The chemical synthesis module is used to receive carbon-containing raw material gas generated by the cement clinker production module and hydrogen gas generated by the hydrogen-oxygen preparation module, and react them to produce olefins.

[0012] In the carbonate decomposition process, methanol undergoes a reduction reaction with carbonate, converting the carbon components in the carbonate decomposition products into a gas containing carbon monoxide.

[0013] As a further improvement to the above technical solution, the cement clinker production module includes a preheating unit, a decomposition unit, a calcination unit and a cooling unit in sequence along the material flow direction. The decomposition unit is a decomposition furnace or a conversion furnace, and the output end of the methanol supply module is connected to the decomposition unit.

[0014] As a further improvement to the above technical solution, the carbonate is calcium carbonate, and the reduction reaction between methanol and calcium carbonate is as follows: The reaction temperature is 500-900℃.

[0015] As a further improvement to the above technical solution, the hydrogen and oxygen preparation module is a water electrolysis device, which includes an alkaline electrolysis cell, a solid oxide electrolysis cell, or a proton exchange membrane electrolysis cell. The oxygen output end of the water electrolysis device is connected to the calcination unit, and the hydrogen output end is connected to the chemical synthesis module.

[0016] As a further improvement to the above technical solution, the chemical synthesis module includes a gas purification unit, a gas proportioning unit, and a synthesis reaction unit connected in sequence. The synthesis reaction unit is a Fischer-Tropsch synthesis reactor, used to convert carbon monoxide and hydrogen into olefins.

[0017] As a further improvement to the above technical solution, the calcination unit is a rotary kiln, in which oxygen is co-combusted with methanol or other fuels, the oxygen concentration in the rotary kiln is ≥90%, and the calcination temperature is 1400~1600℃.

[0018] As a further improvement to the above technical solution, a heat recovery module is also included, which is used to recover the waste heat generated by the calcination unit and the decomposition unit. The waste heat is used to preheat the raw materials, methanol or to power the hydrogen and oxygen preparation module.

[0019] As a further improvement to the above technical solution, the gas purification unit includes a dust removal device, a dehydration device, and an impurity removal device, and the carbon monoxide purity in the purified carbon-containing raw material gas is ≥95%.

[0020] A second objective of this invention is to provide a method for cement production coupled with methanol-promoted decomposition to produce olefins based on the system described above, comprising the following steps:

[0021] S1: After preheating, the raw material is fed into the carbonate decomposition stage, and methanol is introduced at the same time. The methanol reacts with the carbonate in the raw material to produce solid material containing metal oxides and carbon-containing raw material gas.

[0022] S2: The carbon-containing raw material gas generated in step S1 is purified and then mixed with the hydrogen gas generated in the hydrogen-oxygen preparation module in a preset ratio.

[0023] S3: The solid material generated in step S1 is sent to the calcination stage, and oxygen generated by the hydrogen-oxygen preparation module is introduced for combustion and heating to produce cement clinker. The waste heat generated during calcination is recovered and utilized.

[0024] S4: The gas mixed in step S2 is introduced into the chemical synthesis process, where it undergoes a catalytic reaction to produce olefin products;

[0025] S5: Collect the cement clinker produced in step S3 after cooling to complete the co-production of cement and olefins.

[0026] Compared with the prior art, the present invention has significant advantages and beneficial effects, specifically reflected in the following aspects:

[0027] By using in-situ reduction reactions in the decomposition unit, 60% of the process carbon emissions in cement production are directly converted into carbon monoxide, a chemical raw material. This fundamentally changes the direction of carbon flow and overcomes the limitations of traditional end-of-pipe treatment. Emission reduction can reach over 0.35 t / t of calcium carbonate; it eliminates energy-intensive processes such as flue gas carbon capture, compression, purification, and carbon reduction to carbon monoxide, reducing energy consumption and equipment investment in carbon utilization. The overall energy consumption of the system is significantly lower than the traditional "cement production + CCU to olefins" process; the oxygen produced by the hydrogen-oxygen preparation module enhances calcination efficiency and reduces pollutant emissions, while hydrogen precisely matches the olefin synthesis requirements, forming a closed-loop material system; waste heat recovery and utilization in the calcination and decomposition stages achieve cascaded energy utilization and improve the overall energy utilization rate of the system; while stably producing cement clinker, it also co-produces high-value, low-carbon olefins (ethylene and propylene) in high demand in the market, transforming cement plants from single building material producers into comprehensive material and chemical producers, achieving a high degree of unity between economic and environmental benefits and significantly shortening the investment payback period; it can be modified based on existing cement production lines without completely reconstructing the production process, the modification cost is controllable, it is suitable for cement production enterprises of different sizes, and its application prospects are broad. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the system process flow for cement production and methanol-promoted decomposition coupled to produce olefins in an embodiment of the present invention.

[0029] Figure 2 This is a schematic diagram of the specific process flow of the cement production and methanol-promoted decomposition coupled olefin production system in one embodiment of the present invention;

[0030] Figure 3 This is a cross-sectional view of a rotary kiln in one embodiment of the present invention;

[0031] Figure 4 This is a three-dimensional structural schematic diagram of a rotary kiln in one embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of the main structure of the decomposition furnace in one embodiment of the present invention;

[0033] Figure 6 This is a top view of the decomposition furnace in one embodiment of the present invention;

[0034] Figure 7 This is a schematic diagram of the process flow for the coupling of cement production and methanol-promoted decomposition to produce olefins in an embodiment of the present invention.

[0035] Explanation of reference numerals in the attached figures:

[0036] 1-Cement clinker production module; 11-Preheating unit; 12-Decomposition unit; 13-Calcination unit; 14-Cooling unit;

[0037] 2-Methanol supply module; 21-Methanol storage tank; 22-Transfer pump; 23-Distribution pipeline;

[0038] 3-Hydrogen and oxygen preparation module;

[0039] 4-Chemical synthesis module; 41-Gas purification unit; 411-Dust removal device; 412-Dehydration device; 413-Impurity removal device; 42-Gas proportioning unit; 43-Synthesis reaction unit;

[0040] 5-Heat recovery module. Detailed Implementation

[0041] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Furthermore, unless otherwise specified, the above embodiments and features described herein can be combined with each other.

[0042] like Figure 1 As shown, an embodiment of the present invention provides a system for cement production coupled with methanol-promoted decomposition to produce olefins. The system includes a cement clinker production module 1, a methanol supply module 2, a hydrogen and oxygen preparation module 3, and a chemical synthesis module 4, wherein:

[0043] Cement clinker production module 1 is used to complete raw meal preheating, carbonate decomposition, high-temperature calcination and clinker cooling to produce cement clinker;

[0044] Methanol supply module 2 is used to store methanol and supply methanol to the carbonate decomposition stage of cement clinker production module 1. Methanol participates in the carbonate decomposition reaction as a reducing medium.

[0045] The hydrogen and oxygen preparation module 3 is used to generate hydrogen and oxygen. The oxygen is supplied to the calcination stage of the cement clinker production module 1, and the hydrogen is supplied to the chemical synthesis module 4.

[0046] The chemical synthesis module 4 is used to receive carbon-containing raw material gas generated by the cement clinker production module 1 and hydrogen gas generated by the hydrogen-oxygen preparation module 3, and then react to produce olefins.

[0047] In the carbonate decomposition process, methanol undergoes a reduction reaction with carbonate, converting the carbon components in the carbonate decomposition products into a gas containing carbon monoxide.

[0048] This system uses methanol as a reducing medium in the carbonate decomposition stage of cement clinker production, converting the carbon components in the carbonate decomposition products into carbon monoxide-containing gas. This reduces the reaction energy barrier of carbonate decomposition by leveraging the reducing effect of methanol, thereby reducing energy consumption in the cement production process, and also generates carbon-containing raw material gas. Simultaneously, oxygen produced by the hydrogen-oxygen preparation module 3 is supplied to the calcination stage to ensure the oxidation reaction requirements of high-temperature calcination of cement clinker, while hydrogen is supplied to the chemical synthesis module 4 to further synthesize olefins in conjunction with the carbon-containing raw material gas generated in cement production. This achieves process coupling between cement clinker production, methanol decomposition, and olefin synthesis, which not only improves the resource utilization efficiency of carbon components in cement production but also simultaneously produces olefin chemical products, achieving synergistic production of building materials and chemical synthesis. This significantly improves the overall resource utilization rate and economic added value of the process. In addition, the material and energy supply of each module is matched and supplied to each other, optimizing the material and energy flow of the overall process and reducing the input of external raw materials and the emission of waste.

[0049] Specifically, please refer to Figure 1 As shown, in one embodiment of the present invention, the cement clinker production module 1 includes a preheating unit 11, a decomposition unit 12, a calcination unit 13 and a cooling unit 14 in sequence along the material flow direction. The decomposition unit 12 is a decomposition furnace or a conversion furnace, and the output end of the methanol supply module 2 is connected to the decomposition unit 12.

[0050] Specifically, the cement clinker production module 1 is arranged along the material flow direction with a preheating unit 11, a decomposition unit 12, a calcination unit 13, and a cooling unit 14, forming the main cement clinker production line. The preheating unit 11 uses a cyclone preheater or other conventional preheating equipment to preheat the raw materials using the high-temperature waste gas discharged from the calcination unit 13; the decomposition unit 12 is a decomposition furnace or conversion furnace, which is the core site for the reduction reaction of methanol and carbonates; the calcination unit 13 is a rotary kiln, used to calcine the decomposition products into clinker; and the cooling unit 14 is a grate cooler, etc., used to cool the clinker and recover waste heat.

[0051] In decomposition unit 12, methanol undergoes a reduction reaction with carbonates (taking calcium carbonate as an example), and the overall reaction formula is: This reaction couples carbonate decomposition and carbon reduction in situ, with the reaction temperature controlled at 500–900℃ and the mass ratio of methanol to calcium carbonate at 1:10–4:10, ensuring efficient carbonate conversion and full conversion of carbon components into carbon monoxide.

[0052] In the calcination unit 13, the oxygen generated by the hydrogen-oxygen preparation module 3 is co-combusted with methanol or other auxiliary fuels, with an oxygen concentration of ≥90%, which significantly improves combustion efficiency, reduces nitrogen oxide emissions, and generates a high temperature of 1400-1600℃ to meet the calcination requirements of cement clinker; the waste heat generated by calcination is recovered through the heat recovery module 5 to achieve energy cascade utilization.

[0053] Specifically, please refer to Figure 1 As shown, in one embodiment of the present invention, the methanol supply module 2 includes a methanol storage tank 21, a transfer pump 22 and a distribution pipeline 23. Methanol is transported to the decomposition unit 12 through the pipeline and participates in the carbonate decomposition reaction as a reducing medium. Its supply can be dynamically adjusted according to the carbonate content in the raw material.

[0054] Therefore, the methanol supply module 2, through the matching configuration of methanol storage tank 21, transfer pump 22 and distribution pipeline 23, realizes the stable delivery of methanol to the carbonate decomposition unit. At the same time, it can dynamically adjust the methanol supply according to the carbonate content in the raw material. This ensures that the reduction reaction between methanol and carbonate as a reducing medium is fully and efficiently carried out, and that the carbon components in the carbonate decomposition products are stably converted into carbon monoxide-containing raw material gas, providing sufficient and qualified carbon-containing raw materials for subsequent olefin synthesis. It also avoids the problems of excessive methanol supply causing raw material waste and increased load on subsequent gas treatment, or insufficient supply leading to incomplete carbonate decomposition and affecting cement clinker production efficiency. This achieves precise matching and efficient utilization of methanol raw materials, while ensuring the stable and continuous operation of the coupled process of cement clinker production and olefin synthesis.

[0055] Specifically, in one embodiment of the present invention, the carbonate is calcium carbonate, and the reduction reaction between methanol and calcium carbonate is as follows: The reaction temperature is 500-900℃, which matches the conventional process temperature for carbonate decomposition in cement production, eliminating the need for additional temperature control equipment and reducing process modification costs. Simultaneously, the reaction directly decomposes calcium carbonate into CaO, required for cement clinker production, while generating a high proportion of CO-containing carbonaceous feedstock gas, thus eliminating the need for traditional calcium carbonate calcination. The subsequent reduction to CO step reduces energy consumption and process steps, and provides high-purity, high-utilization carbon-containing feedstock gas for subsequent olefin synthesis, improving the feedstock supply efficiency of olefin synthesis. In addition, methanol, as the reducing medium, fully participates in the reaction without generating additional impurities, and will not adversely affect the quality of cement clinker or subsequent chemical synthesis reactions. Under the premise of ensuring normal cement clinker production, the integration of carbonate decomposition and carbon-containing feedstock gas preparation is realized, which greatly improves the feedstock conversion efficiency and overall operating economy of the coupled process.

[0056] Specifically, in one embodiment of the present invention, the hydrogen and oxygen preparation module 3 is a water electrolysis device. The hydrogen and oxygen preparation module 3 includes an alkaline electrolysis cell, a solid oxide electrolysis cell, or a proton exchange membrane electrolysis cell. The oxygen output end of the water electrolysis device is connected to the calcination unit, and the hydrogen output end is connected to the chemical synthesis module 4.

[0057] Specifically, the hydrogen and oxygen preparation module 3 employs water electrolysis technology, including but not limited to alkaline water electrolysis devices, solid oxide electrolyzers (SOEC), and proton exchange membrane electrolyzers (PEM), to produce high-purity hydrogen and oxygen. Oxygen is transported to the calcination unit 13 for enhanced combustion, while hydrogen is transported to the chemical synthesis module 4 as a synthesis raw material.

[0058] Specifically, please refer to Figure 1 As shown, in one embodiment of the present invention, the chemical synthesis module 4 includes a gas purification unit 41, a gas proportioning unit 42, and a synthesis reaction unit 43 connected in sequence. The gas purification unit 41 is used to remove dust, moisture, and trace impurities from the carbon-containing raw material gas generated by the decomposition unit 12. The gas proportioning unit 42 is used to adjust the ratio of carbon-containing raw material gas to hydrogen to meet the requirements of the synthesis reaction. The synthesis reaction unit 43 is a Fischer-Tropsch synthesis reactor, used to convert carbon monoxide and hydrogen into olefins. The purified carbon monoxide and hydrogen are mixed at a molar ratio of 1.8 to 2.2. In the Fischer-Tropsch synthesis reactor, under the catalysis of iron-based or cobalt-based catalysts, at 200 to 350°C and 1.5 to 3.5 MPa, mainly low-carbon olefins such as ethylene and propylene are generated, with a product selectivity of ≥80%.

[0059] In this embodiment, the chemical synthesis module 4 is designed with gas purification, proportioning, and synthesis reaction in a modular, sequential manner. First, the purification unit removes dust, moisture, and trace impurities from the carbon-containing raw material gas, effectively preventing the poisoning of subsequent catalytic reactions and equipment wear, ensuring catalyst activity and stable synthesis reaction. Then, the proportioning unit precisely adjusts the molar ratio of purified carbon monoxide to hydrogen to 1.8–2.2, accurately matching the raw material ratio requirements for Fischer-Tropsch synthesis, laying the raw material foundation for efficient olefin synthesis. Subsequently, in the Fischer-Tropsch synthesis reactor, an iron-based or cobalt-based catalyst is used as the catalytic medium, at 200–350°C and 1.5–3.5 MPa. The synthesis reaction is completed under specific process conditions, which can not only adapt to the characteristics of the raw materials in the coupled process to achieve efficient conversion of carbon monoxide and hydrogen into olefins, but also achieve high selectivity in the production of low-carbon olefins such as ethylene and propylene (product selectivity ≥80%), significantly improving the output efficiency of the target chemical products. The process parameters and unit functions of the entire chemical synthesis module are precisely matched with the raw material supply characteristics of cement production coupled to olefin production, realizing efficient and highly selective conversion of carbon-containing raw material gas into low-carbon olefins. This ensures the stable operation of the chemical synthesis link in the coupled process and the high-quality output of high-value-added products, further improving the process economy and resource utilization value of the entire cement production and methanol-promoted decomposition coupled olefin production system.

[0060] Specifically, in one embodiment of the present invention, the calcination unit 13 is a rotary kiln, in which oxygen is co-combusted with methanol or other fuels, the oxygen concentration in the rotary kiln is ≥90%, and the calcination temperature is 1400~1600℃.

[0061] This scheme sets up the calcination unit 13 as a rotary kiln, which is used in conjunction with the oxygen supplied by the hydrogen-oxygen preparation module 3 and methanol or other fuels for co-combustion. The oxygen concentration in the rotary kiln is controlled to be ≥90%, and the calcination temperature is 1400-1600℃. The high oxygen concentration can significantly improve the fuel combustion efficiency, quickly reach and stably maintain the high temperature conditions required for cement clinker calcination, and ensure the calcination quality and production efficiency of cement clinker. At the same time, the full combustion in the high oxygen environment can reduce the generation of harmful gases such as nitrogen oxides, reduce the tail gas treatment load, and methanol as fuel can further realize the resource utilization of raw materials in the coupled process and avoid raw material waste. The equipment form of the rotary kiln is adapted to the high oxygen and high temperature calcination conditions, which can ensure the continuous and stable operation of the calcination link. It not only meets the process requirements of cement clinker production, but also matches the material and energy supply of the entire coupled system, realizing efficient and clean production in the calcination link, and further optimizing the energy utilization efficiency and environmental protection of the overall system.

[0062] Specifically, please refer to Figure 1 As shown, in one embodiment of the present invention, the cement production and methanol-promoted decomposition coupled olefin production system further includes a heat recovery module 5, which is used to recover the waste heat generated by the calcination unit 13 and the decomposition unit 12. This heat can be used to preheat raw materials and methanol, or to provide energy for the hydrogen-oxygen preparation module 3, thereby improving the system's energy utilization efficiency.

[0063] By recovering the waste heat generated by the calcination unit 13 and the decomposition unit 12, and reusing this waste heat in the energy supply links of the raw material preheating, methanol preheating, and hydrogen-oxygen preparation module 3, the low-grade waste heat of each core unit of cement production is effectively recovered, reducing heat loss within the system and external energy input, and significantly improving the energy utilization efficiency and energy self-sufficiency rate of the entire coupled system. Furthermore, by preheating the raw materials and methanol, the reaction start-up energy consumption of the carbonate decomposition and fuel combustion links is reduced, which helps the efficient operation of each link of the coupled process. At the same time, it provides energy support for the hydrogen-oxygen preparation module 3, further strengthening the recycling of materials and energy within the system, making the coupled process of cement production and methanol decomposition to olefins more energy-efficient and economical.

[0064] Specifically, please refer to Figure 1 As shown, in one embodiment of the present invention, the gas purification unit 41 includes a dust removal device 411, a dehydration device 412 and an impurity removal device 413, and the carbon monoxide purity in the purified carbon-containing raw material gas is ≥95%.

[0065] In this embodiment, the gas purification unit 41 achieves refined purification of carbon-containing raw material gas through step-by-step purification processes involving dust removal, dehydration, and impurity removal devices. This ensures that the purified carbon monoxide purity is ≥95%, effectively removing dust, moisture, and various impurities from the raw material gas. This prevents these impurities from interfering with the accuracy of subsequent gas proportioning, poisoning the synthesis catalyst, or clogging the equipment, thus guaranteeing catalyst activity and the stable and efficient progress of the synthesis reaction. Furthermore, it provides high-purity carbon monoxide raw material for Fischer-Tropsch synthesis. Combined with precisely proportioned hydrogen, this further enhances the synthesis efficiency and product selectivity of low-carbon olefins such as ethylene and propylene. At the same time, the high-purity carbon-containing raw material gas also reduces the occurrence of side reactions in the synthesis reaction, lowers the process load for subsequent product separation, and makes the process connection between chemical synthesis and cement production smoother. Overall, this improves the raw material conversion efficiency and production economy of the coupled olefin production system.

[0066] Please see Figure 7 As shown, another embodiment of the present invention also provides a method for cement production coupled with methanol-promoted decomposition to produce olefins based on the above-described system, the method comprising the following steps:

[0067] S1: After preheating, the raw material is fed into the carbonate decomposition stage, and methanol is introduced at the same time. The methanol reacts with the carbonate in the raw material to produce solid material containing metal oxides and carbon-containing raw gas.

[0068] In this step, the raw material is preheated to above 450°C by the preheating unit 11 and then sent to the decomposition unit 12. At the same time, methanol is introduced into the decomposition unit 12 through the methanol supply module 2. A reduction reaction occurs at 500-900°C to generate solid materials containing metal oxides (mainly CaO) and carbon-containing raw gas containing carbon monoxide. The carbonate conversion rate is ≥90%.

[0069] S2: The carbon-containing raw material gas generated in step S1 is purified and then mixed with the hydrogen gas generated in the hydrogen-oxygen preparation module 3 in a preset ratio.

[0070] In this step, the carbon-containing raw material gas undergoes dust removal, dehydration, and removal of trace impurities (such as sulfur and nitrogen oxides) in sequence through the gas purification unit 41 to obtain carbon monoxide gas with a purity of ≥95%; this gas is then mixed evenly with the hydrogen gas generated by the hydrogen and oxygen preparation module 3 in the gas mixing unit 42 according to a preset molar ratio.

[0071] S3: The solid material generated in step S1 is sent to the calcination stage, and oxygen generated by the hydrogen-oxygen preparation module 3 is introduced for combustion and heating to produce cement clinker. The waste heat generated during calcination is recovered and utilized.

[0072] In this step, solid materials containing metal oxides enter the calcination unit 13 and are co-combusted with oxygen and auxiliary fuel generated by the hydrogen-oxygen preparation module 3 to produce cement clinker at 1400-1600℃. The waste heat generated by calcination is recovered through the heat recovery module 5 and used for raw material preheating, methanol preheating or to supply energy to the hydrogen-oxygen preparation module 3. The waste heat recovery efficiency is ≥70%.

[0073] S4: The gas mixed in step S2 is introduced into the chemical synthesis process, where it undergoes a catalytic reaction to produce olefin products.

[0074] In this step, the mixed carbon monoxide and hydrogen are introduced into the Fischer-Tropsch synthesis reactor, where a synthesis reaction occurs under the action of a catalyst to produce olefin products, mainly ethylene and propylene. After separation and storage, the finished product is obtained.

[0075] S5: Collect the cement clinker produced in step S3 after cooling to complete the co-production of cement and olefins.

[0076] In this step, the high-temperature clinker enters the cooling unit 14 for rapid cooling, and the cooled clinker is stored in the warehouse to complete the co-production of cement and olefins.

[0077] More specifically, in one embodiment of the present invention, the method simultaneously produces two products: cement clinker and low-carbon olefins, mainly composed of ethylene and propylene. For every 1 ton of calcium carbonate consumed, 0.28-0.32 tons of methanol and 75-80 kWh of electricity are consumed simultaneously, generating 0.78-0.82 tons of cement clinker and 0.58-0.62 tons of low-carbon olefins, with a CO2 emission reduction of not less than 0.38 tons.

[0078] More specifically, in one embodiment of the present invention, in step S2, the molar ratio of hydrogen to carbon monoxide in the carbon-containing feed gas is 1.8 to 2.2, and in step S4, the olefin products are mainly ethylene and propylene, with a total selectivity of ≥80%.

[0079] More specifically, in one embodiment of the present invention, the combustion thermal efficiency of the calcination stage in step S3 is ≥85%, the waste heat recovery efficiency is ≥70%, and the recovered waste heat is used for raw material preheating or energy replenishment of the hydrogen-oxygen preparation module 3.

[0080] More specifically, in one embodiment of the present invention, the catalyst for the catalytic reaction in step S4 is an iron-based catalyst or a cobalt-based catalyst, the reaction pressure is 1.5 to 3.5 MPa, and the reaction temperature is 200 to 350°C.

[0081] To verify the above method, such as Figure 2 As shown, a preferred embodiment will be described in detail below:

[0082] Cement clinker production module 1: Preheating unit 11 adopts a five-stage cyclone preheater, decomposition unit 12 is a jet-type decomposition furnace, and calcination unit 13 is... The rotary kiln has a third-generation grate cooler in cooling unit 14.

[0083] Methanol Supply Module 2: Methanol storage tank with a volume of 500m³ 3 It is equipped with two variable frequency delivery pumps, and the decomposition furnace has four methanol atomizing nozzles. Figure 3 , Figure 4 , Figure 5 , Figure 6 The atomized particles are evenly distributed around the furnace circumference and have a particle size ≤50μm.

[0084] Hydrogen and oxygen production module 3: Employs a solid oxide water electrolysis device with a rated hydrogen production capacity of 1000 Nm³. 3 / h, oxygen production is 500 Nm³ 3 / h, with a matching 100m 3 Oxygen buffer tank and 200m 3 Hydrogen buffer tank;

[0085] Chemical synthesis module 4: Gas purification unit 41 includes a pulse bag filter, a molecular sieve dehydration device, and a hydrodesulfurization device. Gas proportioning unit 42 is equipped with an automatic proportioning valve and a flow monitoring device. The Fischer-Tropsch synthesis reactor is a fixed-bed reactor, filled with an iron-based catalyst, with a loading of 50m³. 3 ;

[0086] Heat recovery module 5: includes a waste heat boiler and heat exchange pipelines, which recover waste heat from the rotary kiln and the decomposition furnace respectively.

[0087] Raw materials are conveyed from the raw material silo into a five-stage cyclone preheater, where they are preheated to over 500°C by high-temperature exhaust gas from the rotary kiln (approximately 1000°C). The preheated raw materials, along with methanol from the methanol storage tank, then enter the decomposition furnace.

[0088] Inside the decomposition furnace, the raw materials... and The core reaction occurs at approximately 900°C: The generated solids (mainly CaO) enter the rotary kiln, while the gases (rich in CO and containing a small amount of H2O) enter the subsequent processing unit.

[0089] Inside the rotary kiln, another portion of the methanol from the methanol storage tank mixes with methanol from... The oxygen in the storage tank (generated by a water electrolysis device) undergoes oxygen-enriched combustion, producing a high temperature of approximately 1500℃, which causes CaO to react with other oxides to form cement clinker minerals. , (etc.). The high-temperature clinker then enters a grate cooler for rapid cooling, and the hot air generated during cooling is returned to the system for reuse. Finally, the clinker is stored in the warehouse.

[0090] The CO-rich gas discharged from the decomposition furnace first enters the CO purification and pressurization system, where it undergoes dust removal, dehydration, and removal of trace impurities, and is pressurized to the pressure required for Fischer-Tropsch synthesis (e.g., 2.0-3.0 MPa). The purified CO then mixes with gas from... The hydrogen in the storage tank (generated by a water electrolysis device) is added in a certain proportion (e.g.) After mixing, the mixture enters the Fischer-Tropsch synthesis reactor. Under the action of an iron-based or cobalt-based catalyst, the syngas undergoes a Fischer-Tropsch synthesis reaction, primarily producing low-carbon olefins (…). , (etc.), the products are stored in storage tanks.

[0091] The water electrolysis unit is the energy and material hub of this system. The oxygen produced, after being buffered in a storage tank, provides the oxidant for oxygen-enriched combustion in the rotary kiln, significantly improving combustion efficiency and flame temperature while reducing the total amount of flue gas. The hydrogen produced, after being buffered in a storage tank, serves as an essential feedstock for Fischer-Tropsch synthesis, perfectly matching the CO produced in the decomposition furnace. Methanol plays a triple role in this system: as a chemical reducing agent in the decomposition furnace; as a clean fuel in the rotary kiln; and its carbon and hydrogen molecules are ultimately partially converted into olefin products.

[0092] Through the aforementioned deep integration and innovation, this system has constructed a brand-new "cement-methanol-olefins" industrial chain, which not only solves the carbon emission problem of the cement industry, but also creates huge economic value and provides a practical and feasible technical path for achieving green and sustainable industrial development.

[0093] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the scope of protection of this invention.

Claims

1. A system for coupling cement production with methanol-promoted decomposition to produce olefins, characterized in that, include: The cement clinker production module is used to complete the preheating of raw materials, decomposition of carbonates, high-temperature calcination and cooling of clinker, and to produce cement clinker. A methanol supply module is used to store methanol and supply methanol to the carbonate decomposition stage of the cement clinker production module, wherein the methanol participates in the carbonate decomposition reaction as a reducing medium. The hydrogen and oxygen preparation module is used to generate hydrogen and oxygen. The oxygen is supplied to the calcination stage of the cement clinker production module, and the hydrogen is supplied to the chemical synthesis module. The chemical synthesis module is used to receive carbon-containing raw material gas generated by the cement clinker production module and hydrogen gas generated by the hydrogen-oxygen preparation module, and react them to produce olefins. In the carbonate decomposition process, methanol undergoes a reduction reaction with carbonate, converting the carbon components in the carbonate decomposition products into a gas containing carbon monoxide.

2. The system for cement production coupled with methanol-promoted decomposition to produce olefins according to claim 1, characterized in that, The cement clinker production module includes a preheating unit, a decomposition unit, a calcination unit, and a cooling unit in sequence along the material flow direction. The decomposition unit is a decomposition furnace or a conversion furnace, and the output end of the methanol supply module is connected to the decomposition unit.

3. The system for cement production coupled with methanol-promoted decomposition to produce olefins according to claim 1, characterized in that, The carbonate is calcium carbonate, and the reduction reaction between methanol and calcium carbonate is as follows: The reaction temperature is 500-900℃.

4. The system for cement production coupled with methanol-promoted decomposition to produce olefins according to claim 1, characterized in that, The hydrogen and oxygen preparation module is a water electrolysis device, which includes an alkaline electrolysis cell, a solid oxide electrolysis cell, or a proton exchange membrane electrolysis cell. The oxygen output end of the water electrolysis device is connected to the calcination unit, and the hydrogen output end is connected to the chemical synthesis module.

5. The system for cement production coupled with methanol-promoted decomposition to produce olefins according to claim 1, characterized in that, The chemical synthesis module includes a gas purification unit, a gas proportioning unit, and a synthesis reaction unit connected in sequence. The synthesis reaction unit is a Fischer-Tropsch synthesis reactor, used to convert carbon monoxide and hydrogen into olefins.

6. The system for cement production coupled with methanol-promoted decomposition to produce olefins according to claim 2, characterized in that, The calcination unit is a rotary kiln, in which oxygen is co-combusted with methanol or other fuels, the oxygen concentration in the rotary kiln is ≥90%, and the calcination temperature is 1400~1600℃.

7. The system for cement production coupled with methanol-promoted decomposition to produce olefins according to claim 1, characterized in that, It also includes a heat recovery module for recovering waste heat generated by the calcination and decomposition units, which is used to preheat raw materials, methanol, or to power the hydrogen-oxygen production module.

8. The system for cement production coupled with methanol-promoted decomposition to produce olefins according to claim 5, characterized in that, The gas purification unit includes a dust removal device, a dehydration device, and an impurity removal device. The carbon monoxide purity in the purified carbon-containing raw gas is ≥95%.

9. A method for cement production coupled with methanol-promoted decomposition to produce olefins based on the system described in any one of claims 1-8, characterized in that, Includes the following steps: S1: After preheating, the raw material is fed into the carbonate decomposition stage, and methanol is introduced at the same time. The methanol reacts with the carbonate in the raw material to produce solid material containing metal oxides and carbon-containing raw material gas. S2: The carbon-containing raw material gas generated in step S1 is purified and then mixed with the hydrogen gas generated in the hydrogen-oxygen preparation module in a preset ratio. S3: The solid material generated in step S1 is sent to the calcination stage, and oxygen generated by the hydrogen-oxygen preparation module is introduced for combustion and heating to produce cement clinker. The waste heat generated during calcination is recovered and utilized. S4: The gas mixed in step S2 is introduced into the chemical synthesis process, where it undergoes a catalytic reaction to produce olefin products; S5: Collect the cement clinker produced in step S3 after cooling to complete the co-production of cement and olefins.

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