Cement-chemicals co-production system and control method thereof

Abstract

The application discloses a cement-chemicals co-production system and a control method thereof, and belongs to the technical field of carbon emission reduction and resource utilization in the cement industry. The system comprises a water electrolysis hydrogen production unit, a microwave-assisted hydrogen calcination unit, a cement clinker sintering unit, a synthetic gas purification unit, a synthetic gas proportioning unit, a chemical synthesis unit, a waste heat recovery unit and an automatic control and data monitoring unit. The microwave-assisted hydrogen calcination technology is used to decompose calcium carbonate into CO synthesis gas, oxygen by-product of water electrolysis is used for oxygen-enriched combustion, combined with accurate proportioning of synthetic gas and DCS and artificial intelligence collaborative control, the collaborative production of cement clinker and high-value chemicals is realized. The application reduces the carbon emission of the system by more than 70% compared with the traditional process, reduces the comprehensive energy consumption by more than 30%, the thermal efficiency is greater than or equal to 85%, the synthetic gas conversion rate is greater than or equal to 80%, and the carbon resource utilization rate and production stability are significantly improved, and the application has outstanding economic and environmental benefits.

Description

Technical Field

[0001] This invention belongs to the field of carbon emission reduction and resource utilization technology in the cement industry, specifically relating to a system and control method for the synergistic production of cement clinker and high-value chemicals using microwave-assisted hydrogenation calcination technology. Background Technology

[0002] The cement industry is a major global industry One of the sources of emissions, approximately 60% of carbon emissions, comes from the decomposition of limestone (calcium carbonate). This part in traditional craftsmanship Direct emissions into the atmosphere cause serious greenhouse gas pollution. With increasing global pressure to reduce carbon emissions, the development of low-carbon or even zero-carbon cement production technologies has become an urgent need for the industry.

[0003] Existing carbon reduction technologies in the cement industry mainly include carbon capture, utilization and storage (CCUS), biomass alternative fuels, and oxy-fuel combustion. However, these technologies have significant drawbacks: CCUS technology has high energy consumption and high cost. Low utilization value; biomass fuel is limited by raw material supply, making large-scale application difficult; oxygen-enriched combustion can only reduce carbon emissions from fuel combustion to some extent, but cannot fundamentally solve the problem of carbon emissions from calcium carbonate decomposition. Emissions issues.

[0004] On the other hand, syngas ( As an important chemical raw material, syngas can be used to produce high-end chemicals such as methanol and olefins. Traditional syngas production relies on natural gas reforming or coal gasification technologies, which result in high carbon emissions and high raw material costs. Meanwhile, existing cement-chemical co-production technologies suffer from low heating efficiency, unstable syngas component ratios, insufficient intelligence in control systems, and low carbon resource utilization, making it difficult to achieve efficient synergy between cement production and chemical synthesis. Summary of the Invention

[0005] In view of this, the purpose of this invention is to overcome the shortcomings of the prior art and provide a cement-chemical co-production system and its control method, which uses microwave-assisted hydrogenation calcination technology to decompose calcium carbonate into... It is converted into CO syngas, and combined with precise syngas blending, oxygen-enriched combustion and intelligent control, it enables the synergistic production of cement clinker and high-value chemicals, significantly reducing carbon emissions and overall energy consumption, and improving resource utilization efficiency and production stability.

[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 cement-chemical co-production system, comprising:

[0008] An electrolysis water hydrogen production unit is used to electrolyze water to produce hydrogen and oxygen. The hydrogen is pressurized to 3.0-6.0 MPa, and the oxygen is used for oxygen-enriched combustion.

[0009] A microwave-assisted hydrogenation and calcination unit is connected to the hydrogen outlet of the water electrolysis and hydrogen production unit. It is used to receive raw materials containing calcium carbonate and pressurized hydrogen and react them at 800-950℃ and 3.0-6.0 MPa to produce calcium oxide and synthesis gas containing carbon monoxide. The hydrogenation and calcination unit includes a microwave generator that generates 10-100 GHz microwaves.

[0010] The cement clinker calcination unit is connected to the calcium oxide outlet of the microwave-assisted hydrogenation calcination unit and the oxygen outlet of the water electrolysis hydrogen production unit, and uses oxygen-enriched combustion technology to calcine the cement clinker.

[0011] The syngas purification unit is connected to the syngas outlet of the microwave-assisted hydrogenation and calcination unit and is used to dehydrate, remove dust, deoxygenate, denitrify and desulfurize the syngas.

[0012] The syngas proportioning unit, connected to the outlet of the syngas purification unit, is equipped with an online syngas analyzer and a hydrogen replenishment regulating valve for real-time monitoring. The system controls the CO concentration and automatically adjusts the hydrogen supply flow rate. Target ratio;

[0013] A chemical synthesis unit is connected to the outlet of the synthesis gas proportioning unit and is used to convert the proportioned synthesis gas into high-value chemicals.

[0014] The waste heat recovery unit is used to recover and recycle the waste heat generated by each unit.

[0015] The automated control and data monitoring unit is communicatively connected to the water electrolysis hydrogen production unit, microwave-assisted hydrogenation calcination unit, cement clinker calcination unit, syngas purification unit, chemical synthesis unit, and waste heat recovery unit, respectively, and is used to monitor and adjust the system operating parameters in real time.

[0016] As a further improvement to the above technical solution, the water electrolysis hydrogen production unit includes a water source treatment device, an electrolyzer, and a hydrogen compressor. The water source treatment device sequentially prepares high-purity deionized water through a multi-media filter, an ultrafiltration device, a reverse osmosis device, and an electrodeionization device. The electrolyzer electrolyzes water to produce hydrogen and oxygen, and the hydrogen compressor pressurizes the hydrogen to 3.0-6.0 MPa.

[0017] As a further improvement to the above technical solution, the microwave-assisted hydrogenation calcination unit includes a microwave resonant cavity, a hydrogenation calcination reactor, a gas distribution plate, and a heat exchange tube bundle. The hydrogenation calcination reactor is disposed inside the microwave resonant cavity, and the gas distribution plate is disposed at the bottom of the hydrogenation calcination reactor to ensure that the calcium carbonate particles are in full contact with hydrogen. The heat exchange tube bundle is used for waste heat recovery.

[0018] As a further improvement to the above technical solution, the cement clinker calcination unit includes a rotary kiln, a decomposition furnace, and a grate cooler. The oxygen-enriched combustion system of the rotary kiln controls the oxygen concentration to be 25-30%, the calcination temperature to be 1350-1450℃, and the calcination time to be 20-40 minutes.

[0019] As a further improvement to the above technical solution, the syngas purification unit includes a dehydration device, a dust removal device, a deoxygenation device, a denitrification device, and a desulfurization device connected in sequence. The purified syngas has a water content of less than 10 ppm and a dust content of less than 1 mg / Nm³. 3 The total sulfur content is less than 0.1 ppm.

[0020] As a further improvement to the above technical solution, the control method of the syngas proportioning unit includes:

[0021] Real-time detection of syngas using an online analyzer and CO concentration; calculate current Proportion;

[0022] The deviation value is obtained by comparing the current ratio with the target ratio.

[0023] The opening degree of the hydrogen replenishment regulating valve is adjusted by a control algorithm;

[0024] Feedforward control is performed based on the total syngas flow rate to adjust the hydrogen flow rate setpoint in advance.

[0025] As a further improvement to the above technical solution, the syngas proportioning unit is equipped with a safety interlock protection, when When the ratio exceeds the safety limit, the hydrogen replenishment valve will be automatically shut off.

[0026] As a further improvement to the above technical solution, the automated control and data monitoring unit includes a distributed control system and an artificial intelligence system. The distributed control system realizes automatic control of each unit, and the artificial intelligence system includes a predictive maintenance module, an intelligent optimization module, and a safety diagnosis module.

[0027] As a further improvement to the above technical solution, the automated control and data monitoring unit executes the following control method:

[0028] The hydrogen pressure control loop maintains the reactor inlet hydrogen pressure within the set value ±0.1 MPa range; the reaction temperature control loop controls the reaction temperature within the set value ±5℃ range by adjusting the microwave power and the cold hydrogen injection rate.

[0029] The oxygen concentration control loop maintains the oxygen content at the kiln tail gas within the range of 1%-3% based on the oxygen content of the rotary kiln tail gas.

[0030] As a further improvement to the above technical solution, the chemical synthesis unit adopts a Fischer-Tropsch synthesis reactor, which is a slurry bed or fixed bed reactor, uses a cobalt-based or iron-based catalyst, has a reaction temperature of 200-250℃, a pressure of 2.0-3.0 MPa, a syngas conversion rate of ≥80%, and a target chemical selectivity of ≥70%.

[0031] The second objective of this invention is to provide a control method for a cement-chemical co-production system, comprising the following steps:

[0032] S1: Utilize renewable energy to generate electricity, and electrolyze water to produce hydrogen and oxygen through a water electrolysis hydrogen production unit. The hydrogen is pressurized to 3.0-6.0 MPa, and the oxygen is transported to the cement clinker calcination unit.

[0033] S2: Raw materials containing calcium carbonate and pressurized hydrogen enter the microwave-assisted hydrogenation calcination unit, where they react under microwave assistance at 10-100 GHz at 800-950℃ and 3.0-6.0 MPa to produce calcium oxide and syngas;

[0034] S3: Calcium oxide is fed into the cement clinker calcination unit and burned in oxygen-enriched combustion to produce cement clinker.

[0035] S4: Syngas undergoes dehydration, dust removal, deoxygenation, denitrification and desulfurization treatment in sequence through the syngas purification unit;

[0036] S5: The purified syngas enters the syngas proportioning unit, which is monitored in real time. The system automatically adjusts the hydrogen supply flow rate based on CO concentration to control... The proportion has reached the target value;

[0037] S6: The blended syngas is sent to the chemical synthesis unit and converted into high-value chemicals;

[0038] S7: Waste heat from each unit is recovered through the waste heat recovery unit and used for raw material drying, equipment heating or power generation;

[0039] S8: The system operating parameters are monitored and adjusted in real time through the automated control and data monitoring unit to ensure stable and efficient system operation.

[0040] As a further improvement to the above technical solution, in step S2, the molar ratio of hydrogen to calcium carbonate is (2-4):1, the reaction time is 1-3 hours, and the reaction path includes in-situ hydrogenation decomposition of calcium carbonate and reverse water-gas shift reaction. The reaction formula for the in-situ hydrogenation decomposition is as follows: The reverse water gas shift reaction formula is: .

[0041] Compared with the prior art, the present invention has significant advantages and beneficial effects, specifically reflected in the following aspects:

[0042] The product obtained by decomposing calcium carbonate using microwave-assisted hydrogenation calcination technology It is converted into CO syngas, avoiding the problems associated with traditional processes. Direct emissions are reduced by more than 70% compared to traditional processes, achieving deep decarbonization in the cement industry. Carbon resources from cement production are converted into high-value chemicals, enabling carbon resource recycling. Simultaneously, the waste heat recovery system achieves a thermal efficiency of ≥85%, reducing overall energy consumption by more than 30%, significantly improving resource and energy utilization efficiency. Co-production of cement clinker (output ≥3000 t / d) and high-value chemicals (output ≥500 t / d) enriches the product structure and enhances economic benefits and market competitiveness. The syngas proportioning unit achieves… With precise proportional control, the automated control and data monitoring unit collaborates with DCS and artificial intelligence to achieve real-time optimization of process parameters and fault early warning, significantly improving the stability and reliability of system operation. It can be retrofitted using existing cement production lines without complete reconstruction, resulting in low retrofit costs. It is suitable for large-scale application needs in the cement industry and conforms to the national "dual carbon" policy. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the structural framework of the cement-chemical co-production system in an embodiment of the present invention;

[0044] Figure 2 This is a schematic diagram of the water treatment device in an embodiment of the present invention;

[0045] Figure 3 This is a schematic diagram of the waste heat recovery unit in an embodiment of the present invention;

[0046] Figure 4 This is a schematic diagram of the structure of the automated control and data monitoring unit in an embodiment of the present invention;

[0047] Figure 5 This is a schematic diagram of the structure of the automated control and data monitoring unit in an embodiment of the present invention;

[0048] Figure 6 This is a schematic diagram of the syngas purification and proportioning unit in an embodiment of the present invention;

[0049] Figure 7 This is a schematic diagram of the energy flow in the waste heat recovery unit in an embodiment of the present invention;

[0050] Figure 8 This is a flowchart illustrating the control logic of the automation control and data monitoring unit in this embodiment of the invention.

[0051] Figure 9 This is a comparison diagram of the effects of the embodiments of the present invention and the traditional process;

[0052] Figure 10 This is a schematic diagram illustrating the specific process of the control method for the cement-chemical co-production system in an embodiment of the present invention.

[0053] Explanation of reference numerals in the attached figures:

[0054] 1-Water electrolysis hydrogen production unit; 11-Water source treatment device; 111-Multi-media filter; 112-Ultrafiltration device; 113-Reverse osmosis device; 114-Electrodeionization device; 12-Electrolyzer; 13-Hydrogen compressor;

[0055] 2-Microwave-assisted hydrogenation calcination unit; 21-Microwave resonant cavity; 22-Hydrogenation calcination reactor; 23-Gas distribution plate; 24-Heat exchange tube bundle;

[0056] 3-Cement clinker calcination unit; 31-Rotary kiln; 32-Decomposition furnace; 33-Grate cooler;

[0057] 4-Synthesis gas purification unit; 41-Dehydration device; 42-Dust removal device; 43-Deoxygenation device; 44-Denitrification device; 45-Desulfurization device;

[0058] 5-Synthesis gas proportioning unit; 51-Synthesis gas online analyzer; 52-Supplemental hydrogen regulating valve;

[0059] 6-Chemical synthesis unit;

[0060] 7-Waste heat recovery unit; 71-Waste heat boiler; 72-Waste heat boiler; 73-Heat exchanger;

[0061] 8-Automatic control and data monitoring unit; 81-Distributed control system; 82-Artificial intelligence system; 821-Predictive maintenance module; 822-Intelligent optimization module; 823-Safety diagnosis module. Detailed Implementation

[0062] 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.

[0063] like Figure 1-4 As shown, an embodiment of the present invention provides a cement-chemical co-production system, which includes an electrolytic water hydrogen production unit 1, a microwave-assisted hydrogenation calcination unit 2, a cement clinker calcination unit 3, a syngas purification unit 4, a syngas proportioning unit 5, a chemical synthesis unit 6, a waste heat recovery unit 7, and an automated control and data monitoring unit 8, wherein:

[0064] The water electrolysis hydrogen production unit 1 is used to electrolyze water to produce hydrogen and oxygen. The hydrogen is pressurized to 3.0-6.0 MPa, and the oxygen is used for oxygen-enriched combustion.

[0065] The microwave-assisted hydrogenation calcination unit 2 is connected to the hydrogen outlet of the water electrolysis hydrogen production unit 1. It is used to receive raw materials containing calcium carbonate and pressurized hydrogen gas to react at 800-950℃ and 3.0-6.0 MPa to produce calcium oxide and synthesis gas containing carbon monoxide. The microwave-assisted hydrogenation calcination unit 2 includes a microwave generator that generates 10-100 GHz microwaves.

[0066] The cement clinker calcination unit 3 is connected to the calcium oxide outlet of the microwave-assisted hydrogenation calcination unit 2 and the oxygen outlet of the water electrolysis hydrogen production unit 1, and the cement clinker is calcined using oxygen-enriched combustion technology.

[0067] Syngas purification unit 4 is connected to the syngas outlet of microwave-assisted hydrogenation and calcination unit 2, and is used to dehydrate, remove dust, deoxygenate, denitrify and desulfurize the syngas.

[0068] The syngas proportioning unit 5 is connected to the outlet of the syngas purification unit 4, and is equipped with an online syngas analyzer 51 and a hydrogen replenishment regulating valve 52 for real-time monitoring. The system controls the CO concentration and automatically adjusts the hydrogen supply flow rate. Target ratio;

[0069] The chemical synthesis unit 6 is connected to the outlet of the synthesis gas proportioning unit 5, and is used to convert the proportioned synthesis gas into high-value chemicals.

[0070] Waste heat recovery unit 7 is used to recover and recycle the waste heat generated by each unit;

[0071] The automation control and data monitoring unit 8 is connected in communication with the above-mentioned water electrolysis hydrogen production unit 1, microwave-assisted hydrogenation calcination unit 2, cement clinker calcination unit 3, syngas purification unit 4, syngas proportioning unit 5, chemical synthesis unit 6, and waste heat recovery unit 7, and is used to monitor and adjust the system operating parameters in real time.

[0072] In this embodiment, hydrogen is produced by the water electrolysis hydrogen production unit 1 and pressurized to 3.0-6.0 MPa. Oxygen is used for oxygen-enriched combustion. In conjunction with the microwave-assisted hydrogenation calcination unit 2, calcium carbonate-containing raw materials are hydrogenated and calcined under pressurized microwave conditions of 800-950℃ and 3.0-6.0 MPa. This utilizes the high-efficiency heating characteristics of 10-100GHz microwaves to improve the calcination reaction rate and calcium carbonate decomposition efficiency. At the same time, calcium oxide and carbon monoxide-containing syngas are generated through the hydrogenation reaction, realizing the conversion of raw materials into calcium oxide, the basic raw material for cement clinker, and the co-production of syngas. The cement clinker calcination unit 3, combined with oxygen-enriched combustion technology, further improves the combustion efficiency of clinker calcination and reduces energy consumption. After impurities are removed by the purification unit 4, the syngas is precisely regulated by the proportioning unit equipped with an online syngas analyzer 51 and a hydrogen replenishment regulating valve 52. The system ensures that the chemical synthesis unit 6 can stably convert syngas into high-value chemicals, while the waste heat recovery unit 7 realizes the recycling of waste heat from each unit. The automation control and data monitoring unit 8 monitors and adjusts the parameters of the entire system in real time, ensuring the coordinated and stable operation of each unit. The overall system realizes the co-production of cement production and chemical synthesis, which greatly improves the resource utilization rate of calcium carbonate raw materials. The integrated application of technologies such as pressurized microwave hydrogenation calcination, oxygen-enriched combustion, and waste heat recovery significantly reduces the overall energy consumption of production. Furthermore, through precise syngas ratio control and full-system automation control, the system ensures the stable production of cement clinker and high-value chemicals, achieving the technical effects of comprehensive resource utilization, energy saving and consumption reduction, and production stability.

[0073] Specifically, please refer to Figure 1 As shown, in one embodiment of the present invention, the water electrolysis hydrogen production unit 1 includes a water source treatment device 11, an electrolytic cell 12, and a hydrogen compressor 13. The water source treatment device 11 sequentially treats the raw water into high-purity demineralized water through a multi-media filter 111, an ultrafiltration device 112, a reverse osmosis device 113, and an electrodeionization device 114. The electrolytic cell 12 electrolyzes water to produce hydrogen and oxygen. The hydrogen compressor 13 pressurizes the hydrogen to 3.0-6.0 MPa and supplies it to the microwave-assisted hydrogenation calcination unit 2. The oxygen is then transported to the cement clinker calcination unit 3 for oxygen-enriched combustion.

[0074] In a specific embodiment of the present invention, the water electrolysis hydrogen production unit 1 adopts a proton exchange membrane electrolyzer with a hydrogen production capacity of 24,000 Nm³. 3 / h, the water treatment device 11 sequentially produces high-purity demineralized water through a multi-media filter 111, an ultrafiltration device 112, a reverse osmosis device 113, and an electro-deionization device 114, and the hydrogen compressor 1 pressurizes the hydrogen to 4.0 MPa.

[0075] Therefore, the water electrolysis hydrogen production unit 1 is specifically configured with a water treatment device 11, an electrolyzer 12, and a hydrogen compressor 13. The water treatment device 11 purifies the raw water through a multi-media filter 111, an ultrafiltration device 112, a reverse osmosis device 113, and an electro-deionization device 114, converting the raw water into high-purity desalinated water. This provides high-quality raw material for the electrolyzer to produce hydrogen, effectively preventing impurities in the raw water from causing blockages, corrosion, or other damage to the electrolyzer, ensuring stable operation and hydrogen production efficiency. Simultaneously, it improves the purity of hydrogen and oxygen. The hydrogen is precisely pressurized to 3.0-6.0 MPa by the hydrogen compressor 13. The microwave-assisted hydrogenation calcination unit 2 is then supplied with hydrogen and oxygen, which can be directly matched to the pressurized reaction conditions of the unit without the need for additional pressurization equipment, thus reducing energy consumption and system complexity. High-purity oxygen is delivered to the cement clinker calcination unit 3 for oxygen-enriched combustion, which can improve combustion intensity and burnout rate, and reduce energy consumption and pollutant emissions during the calcination process. The refined design of the water electrolysis hydrogen production unit 1 not only ensures the efficient, stable, and long-cycle operation of its own hydrogen production process, but also provides hydrogen and oxygen with pressure and purity matching the operating conditions of the subsequent microwave-assisted hydrogenation calcination unit 2 and cement clinker calcination unit 3, achieving process synergy with the subsequent units and contributing to the energy-efficient and high-performance operation of the entire cement-chemical co-production system.

[0076] Specifically, please refer to Figure 1 As shown, in one embodiment of the present invention, the microwave-assisted hydrogenation calcination unit 2 includes a microwave resonant cavity 21, a hydrogenation calcination reactor 22, a gas distribution plate 23, and a heat exchange tube bundle 24. The hydrogenation calcination reactor 22 is disposed in the microwave resonant cavity 21, and the gas distribution plate 23 is disposed at the bottom of the hydrogenation calcination reactor 22 to ensure that the calcium carbonate particles are in full contact with hydrogen. The heat exchange tube bundle 24 is used for waste heat recovery.

[0077] In this embodiment, the microwave-assisted hydrogenation calcination unit 2 is connected to the hydrogen outlet of the water electrolysis hydrogen production unit 1. The hydrogenation calcination reactor 22 is set in the microwave resonant cavity 21. The microwave generator produces 10-100 GHz microwave-assisted heating. The gas distribution plate 23 ensures that the calcium carbonate particles are in full contact with the hydrogen. The reaction is carried out at 800-950°C and 3.0-6.0 MPa to generate calcium oxide and synthesis gas containing carbon monoxide. The molar ratio of hydrogen to calcium carbonate is (2-4):1, and the reaction time is 1-3 hours.

[0078] Specifically, in this embodiment, the microwave-assisted hydrogenation calcination unit 2 is equipped with four parallel microwave fluidized bed reactors, each with a processing capacity of 60 t / h of calcium carbonate. The microwave generator produces 30 GHz microwaves, the reaction temperature is controlled at 850±10℃, the pressure is 4.0±0.2 MPa, and the molar ratio of hydrogen to calcium carbonate is 3:1.

[0079] Therefore, by refining the microwave-assisted hydrogenation calcination unit 2 with a microwave resonant cavity 21, a hydrogenation calcination reactor 22, a gas distribution plate 23, and a heat exchange tube bundle 24, and placing the hydrogenation calcination reactor 22 inside the microwave resonant cavity 21, the reactants in the reactor can fully receive 10-100 GHz signals. Microwave energy enables direct auxiliary heating of the reaction, improving heating uniformity and energy utilization efficiency, and accelerating the reaction rate of calcium carbonate and hydrogen. The gas distribution plate 23 at the bottom allows the pressurized hydrogen to be evenly dispersed in the reactor, ensuring full and comprehensive contact between calcium carbonate particles and hydrogen, avoiding incomplete local reactions, and improving the generation efficiency and product quality of calcium oxide and syngas. At the same time, the heat exchange tube bundle 24 can recover the waste heat in the unit in a timely manner, and reuse the recovered waste heat for system production, reducing the external energy input of the system. The refined structural design of this unit not only ensures the efficient and stable progress of the hydrogenation calcination reaction through microwave directional heating and full gas-solid contact, but also realizes the on-site recovery and utilization of waste heat in the unit, further improving the energy utilization efficiency of the entire cement-chemical co-production system and reducing production energy consumption.

[0080] Specifically, please refer to Figure 1 As shown, in one embodiment of the present invention, the cement clinker calcination unit 3 is connected to the calcium oxide outlet of the microwave-assisted hydrogenation calcination unit 2 and the oxygen outlet of the water electrolysis hydrogen production unit 1. The cement clinker calcination unit 3 includes a rotary kiln 31, a decomposition furnace 32 and a grate cooler 33. The rotary kiln 31 adopts oxygen-enriched combustion technology. The oxygen-enriched combustion system of the rotary kiln 31 controls the oxygen concentration to be 25-30%, the calcination temperature to be 1350-1450℃, and the calcination time to be 20-40 minutes. Calcium oxide is calcined to form cement clinker, and the clinker is collected after being cooled by the grate cooler.

[0081] Specifically, in this embodiment, the oxygen concentration of the primary air at the kiln head of the cement clinker calcination unit 3 is controlled at 28%, the calcination temperature is 1400℃, the calcination time is 30 minutes, and the grate cooler 33 cools the clinker to 60-90℃.

[0082] Therefore, by refining the cement clinker calcination unit 3 with a rotary kiln 31, a decomposition furnace 32, and a grate cooler 33, the rotary kiln 31 and 32, in combination with the decomposition furnace, form a suitable clinker calcination process system. Simultaneously, by employing oxygen-enriched combustion technology and precisely controlling the oxygen concentration to 25-30%, the combustion intensity and heat transfer efficiency within the furnace are effectively improved compared to conventional combustion methods. Combined with a calcination temperature of 1350-1450℃ and a 20-40℃... Precise parameter control of the firing time (minutes) allows the calcium oxide from the microwave-assisted hydrogenation calcination unit 2 to fully react and form high-quality cement clinker. Oxygen-enriched combustion reduces the generation of pollutants such as nitrogen oxides during combustion. The grate cooler 33 can quickly cool the fired clinker, achieving efficient collection of the clinker. At the same time, the sensible heat of the clinker can be recovered and reused in the system during the cooling process. The structural design and process parameters of this unit are precisely matched, which not only ensures the efficient and high-quality firing of cement clinker, but also further reduces the energy consumption and pollutant emissions of the firing process through oxygen-enriched combustion and waste heat recovery, achieving efficient synergy with other units in the cogeneration system.

[0083] Specifically, please refer to Figure 1 As shown, in one embodiment of the present invention, the syngas purification unit 4 is connected to the syngas outlet of the microwave-assisted hydrogenation calcination unit 2. The syngas purification unit 4 includes a dehydration device 41, a dust removal device 42, a deoxygenation device 43, a denitrification device 44, and a desulfurization device 45 connected in sequence. The dehydration device 41 adopts molecular sieve adsorption or cryogenic separation technology, the dust removal device 42 adopts a cyclone separator or a bag filter, the deoxygenation device 43 adopts catalytic deoxygenation technology, the denitrification device 44 adopts pressure swing adsorption or cryogenic separation technology, and the desulfurization device 45 adopts zinc oxide desulfurization or activated carbon adsorption technology. The purified syngas has a water content of <10 ppm, a dust content of <1 mg / Nm3, and a total sulfur content of <0.1 ppm.

[0084] Therefore, the syngas purification unit 4 is configured as a series of interconnected devices for dehydration, dust removal, deoxygenation, denitrification, and desulfurization. Each device is matched with appropriate technologies including molecular sieve adsorption / cryogenic separation, cyclone separation / bag filter dust collection, catalytic deoxygenation, pressure swing adsorption / cryogenic separation, and zinc oxide desulfurization / activated carbon adsorption. Through a multi-stage purification process, impurities such as water, dust, oxygen, nitrogen, and sulfur are precisely removed from the syngas. The purified syngas has a water content of less than 10 ppm, a dust content of less than 1 mg / Nm³, and a total sulfur content of less than 0.1 ppm. This effectively removes impurities that could interfere with subsequent syngas proportioning and chemical synthesis, preventing inaccurate online analyzer detection in the proportioning unit, blockage of the hydrogen replenishment regulating valve, and catalyst poisoning or deactivation in the chemical synthesis unit. This ensures stable operation of subsequent units and extends catalyst lifespan. Simultaneously, the high-purity syngas also facilitates precise control... The proportion and stability of the synthesis of high-value chemicals provide a high-quality raw material base, ensuring the process continuity and product quality stability of syngas from the co-production system to the chemical synthesis stage.

[0085] Specifically, in one embodiment of the present invention, the syngas proportioning unit 5 is connected to the outlet of the syngas purification unit 4. The syngas proportioning unit 5 includes an online gas analyzer 51, a hydrogen replenishment regulating valve 52, and a mixing device 53. The online gas analyzer 51 employs an infrared analyzer or a laser analyzer to detect the syngas in real time. and CO concentration. The control methods for the syngas proportioning unit 5 include:

[0086] Real-time detection of syngas using an online analyzer and CO concentration;

[0087] Calculate the current Proportion;

[0088] The deviation value is obtained by comparing the current ratio with the target ratio.

[0089] The opening degree of the hydrogen replenishment regulating valve is adjusted by a control algorithm;

[0090] Feedforward control is performed based on the total syngas flow rate to adjust the hydrogen flow rate setpoint in advance.

[0091] Therefore, by refining the syngas proportioning unit 5 with an online syngas gas analyzer 51, a hydrogen replenishment regulating valve 52, and a mixing device, infrared or laser detection technology is matched to the analyzer to ensure the real-time and accurate detection of H2 and CO concentrations. Simultaneously, a control method is designed that includes real-time detection, proportion calculation, deviation comparison, valve opening adjustment, and feedforward control, thereby correcting the current situation in a timely manner through closed-loop regulation. The deviation between the ratio and the target ratio is addressed by using feedforward control based on the total syngas flow rate to adjust the hydrogen flow rate setpoint in advance. This achieves precise, rapid, and proactive control of the syngas ratio, effectively avoiding the lag problem of simple feedback control and ensuring the quality of the blended syngas. The ratio remains stable at the target value, providing precise and stable raw materials for the chemical synthesis unit, ensuring the efficient progress of chemical synthesis reactions and the stable production of high-value chemicals. At the same time, the mixing device allows the supplementary hydrogen to be fully mixed with the purified syngas, further improving the uniformity of the syngas ratio and contributing to the process stability and product quality consistency of the syngas utilization stage in the entire cogeneration system.

[0092] It should be noted that the syngas proportioning unit 5 is equipped with a safety interlock protection. When the ratio exceeds the safety limit, the hydrogen supply valve 52 will automatically shut off to ensure safety. The ratio stabilizes at the target value.

[0093] Specifically, please refer to Figure 3 As shown, in one embodiment of the present invention, the waste heat recovery unit 7 includes a waste heat boiler 71, a waste heat boiler 72, and a heat exchanger 73. The waste heat recovery unit recovers the waste heat from the 900°C crude syngas of the microwave-assisted hydrogenation calcination unit to generate medium-pressure steam. The waste heat boiler 72 recovers the waste heat from the 350°C kiln tail exhaust gas of the cement clinker calcination unit to generate low-pressure steam. The heat exchanger 73 is used for raw material drying and equipment heating, and the system thermal efficiency is ≥85%.

[0094] Therefore, the waste heat recovery unit 7 is further refined by setting up a waste heat boiler 71, a waste heat boiler 72, and a heat exchanger 73. The waste heat boiler 71 specifically recovers the waste heat from the 2900℃ crude syngas of the microwave-assisted hydrogenation calcination unit and generates medium-pressure steam, while the waste heat boiler 72 recovers the waste heat from the 350℃ kiln tail exhaust gas of the cement clinker calcination unit 3 and generates low-pressure steam. The recovered waste heat is then reused in the production processes of raw material drying and equipment heating through the heat exchanger 73. This achieves graded recovery and targeted efficient utilization of waste heat from different temperatures and sources within the system, enabling the system's thermal efficiency to reach a high level of ≥85%. This significantly reduces the system's dependence on external energy sources and effectively reduces the production energy consumption of the entire cement-chemicals co-production system. At the same time, the full recovery of waste heat also reduces the system's heat emissions, improves the system's comprehensive energy utilization efficiency, and further strengthens the technological advantages of energy saving and consumption reduction in the co-production system.

[0095] Specifically, please refer to Figure 4 As shown, in one embodiment of the present invention, the automation control and data monitoring unit 8 includes a distributed control system 81 and an artificial intelligence system 82. The distributed control system 81 includes a field instrument layer 811, a process control layer 812, and a factory monitoring layer 813, realizing automatic control of each unit. The artificial intelligence system 82 includes a predictive maintenance module 821, an intelligent optimization module 822, and a safety diagnosis module 823. The predictive maintenance module 821 predicts faults and issues warnings based on equipment operating data. The intelligent optimization module 822 uses a deep reinforcement learning algorithm to dynamically optimize process parameters. The safety diagnosis module 823 identifies abnormal operating conditions and executes safety interlocks based on multivariate correlation analysis, realizing real-time monitoring and optimization of more than 4,000 I / O points.

[0096] Specifically, in one embodiment of the present invention, the automation control and data monitoring unit 8 performs the following control method:

[0097] The hydrogen pressure control loop maintains the reactor inlet hydrogen pressure within the set value ±0.1 MPa range;

[0098] The reaction temperature control loop controls the reaction temperature within a set value ±5℃ by adjusting the microwave power and the amount of cold hydrogen injected.

[0099] The oxygen concentration control loop maintains the oxygen content at the kiln tail gas within the range of 1%-3% based on the oxygen content of the rotary kiln tail gas.

[0100] Specifically, in one embodiment of the present invention, the chemical synthesis unit 6 is connected to the outlet of the syngas proportioning unit 5. The chemical synthesis unit 6 adopts a Fischer-Tropsch synthesis reactor, which is a slurry bed or fixed bed reactor, using a cobalt-based or iron-based catalyst. The reaction temperature is 200-250°C and the pressure is 2.0-3.0 MPa. The syngas is converted into high-value chemicals such as methanol and olefins, with a syngas conversion rate ≥80% and a target chemical selectivity ≥70%.

[0101] Please see Figures 5-9 As shown, to further verify the effectiveness of the above-mentioned cement-chemical co-production system, the following detailed description is provided with reference to specific embodiments, the structure of which is as follows:

[0102] Electrolysis water hydrogen production unit 1: A proton exchange membrane electrolyzer is used, with a hydrogen production capacity of 24000 Nm³ / h. The water source treatment device 11 sequentially produces high-purity deionized water through a multi-media filter 111, an ultrafiltration device 112, a reverse osmosis device 113, and an electrodeionization device 114. The hydrogen compressor 13 pressurizes the hydrogen to 4.0 MPa.

[0103] Microwave-assisted hydrogenation calcination unit 2: Equipped with 4 parallel microwave fluidized bed reactors, each with a processing capacity of 60 t / h of calcium carbonate. The microwave generator produces 30 GHz microwaves, the reaction temperature is controlled at 850±10℃, the pressure is 4.0±0.2MPa, and the molar ratio of hydrogen to calcium carbonate is 3:1.

[0104] Cement clinker firing unit 3: Rotary kiln 31 adopts oxygen-enriched combustion technology, the oxygen concentration of primary air at the kiln head is controlled at 28%, the firing temperature is 1400℃, the firing time is 30 minutes, and the grate cooler 33 cools the clinker to 60-90℃.

[0105] Syngas purification unit 4: Dehydration device 41 adopts molecular sieve adsorption technology, dust removal device 42 adopts bag filter dust collector, deoxygenation device 43 adopts catalytic deoxygenation technology, denitrification device 44 adopts pressure swing adsorption technology, and desulfurization device 45 adopts zinc oxide desulfurization technology. After purification, the water content in the syngas is <8 ppm, the dust content is <0.8 mg / Nm³, and the total sulfur content is <0.08 ppm.

[0106] Syngas Proportioning Unit 4: Employs an infrared online gas analyzer for real-time detection. and CO concentration, control The ratio is 2.0±0.05, with safety interlock protection and a safety upper limit of 3.0;

[0107] Chemical synthesis unit 6: A slurry-bed Fischer-Tropsch synthesis reactor is used with a cobalt-based catalyst at a reaction temperature of 230°C and a pressure of 2.5 MPa.

[0108] Waste heat recovery unit 7: The waste heat boiler recovers the waste heat of 900℃ crude syngas to generate medium-pressure steam, and the waste heat boiler recovers the waste heat of 350℃ kiln tail exhaust gas to generate low-pressure steam. The heat exchanger is used for raw material drying. The system thermal efficiency is ≥86%.

[0109] Automation Control and Data Monitoring Unit 8: The DCS system enables automatic control of each unit, while the artificial intelligence system enables predictive maintenance, intelligent optimization, and safety diagnosis, monitoring 4200 I / O points.

[0110] Please see Figure 10 As shown, another embodiment of the present invention also provides a control method for a cement-chemical co-production system, the control method comprising the following steps:

[0111] S1: Utilize renewable energy to generate electricity, and electrolyze water to produce hydrogen and oxygen through water electrolysis hydrogen production unit 1. The hydrogen is pressurized to 3.0-6.0 MPa, and the oxygen is transported to cement clinker calcination unit 3;

[0112] S2: Raw materials containing calcium carbonate and pressurized hydrogen enter microwave-assisted hydrogenation calcination unit 2, where they react under microwave assistance at 10-100 GHz at 800-950℃ and 3.0-6.0 MPa to produce calcium oxide and syngas;

[0113] S3: Calcium oxide is fed into cement clinker firing unit 3 and is burned in oxygen-enriched combustion to produce cement clinker.

[0114] S4: Syngas undergoes dehydration, dust removal, deoxygenation, denitrification and desulfurization treatment sequentially in syngas purification unit 4;

[0115] S5: The purified syngas enters the syngas proportioning unit 5, where H2 and CO concentrations are monitored in real time, and the hydrogen replenishment flow rate is automatically adjusted and controlled. The proportion has reached the target value;

[0116] S6: The blended syngas is sent into chemical synthesis unit 6 and converted into high-value chemicals;

[0117] S7: Waste heat from each unit is recovered through waste heat recovery unit 7 and used for raw material drying, equipment heating or power generation;

[0118] S8: The system operating parameters are monitored and adjusted in real time through the automation control and data monitoring unit 8 to ensure stable and efficient system operation.

[0119] Specifically, in this embodiment, in step S2, the molar ratio of hydrogen to calcium carbonate is (2-4):1, the reaction time is 1-3 hours, and the reaction pathway includes in-situ hydrogenation decomposition of calcium carbonate and reverse water-gas shift reaction. The reaction formula for the in-situ hydrogenation decomposition is as follows: The reverse water gas shift reaction formula is: .

[0120] Specifically, in this embodiment, the method for controlling the co-production of cement and chemicals using the above system includes the following steps:

[0121] The system generates electricity using solar and wind power, and produces hydrogen and oxygen by electrolyzing water in a water electrolysis unit. The hydrogen is pressurized to 4.0 MPa, and the oxygen is delivered to the cement clinker calcination unit.

[0122] Raw materials containing calcium carbonate (limestone accounting for 91% by mass, with the remainder being corrective raw materials such as steel slag) and pressurized hydrogen are introduced into a microwave-assisted hydrogenation calcination unit. Under the assistance of a 30 GHz microwave, the reaction is carried out at 850 °C and 4.0 MPa for 1.5 hours to produce calcium oxide and syngas.

[0123] Calcium oxide is fed into the cement clinker calcination unit and calcined at 1400℃ and 28% oxygen concentration for 30 minutes to form cement clinker, which is then collected after being cooled by a grate cooler.

[0124] The syngas undergoes dehydration, dust removal, deoxygenation, denitrification, and desulfurization treatments in a syngas purification unit to obtain high-purity syngas.

[0125] The purified syngas enters the syngas proportioning unit, where it is monitored in real time by an online analyzer. The system automatically adjusts the hydrogen supply flow rate based on CO concentration to control [the system's performance]. The ratio is 2.0 ± 0.05;

[0126] The blended syngas is fed into the chemical synthesis unit, where it is catalyzed by a cobalt-based catalyst to be converted into low-carbon olefins at 230°C and 2.5 MPa.

[0127] Waste heat from crude syngas and kiln tail exhaust gas is recovered through a waste heat recovery unit and used for raw material drying and equipment heating.

[0128] The system uses an automated control and data monitoring unit to monitor parameters such as hydrogen pressure, reaction temperature, and oxygen concentration in real time, and dynamically optimizes and adjusts these parameters to ensure stable system operation.

[0129] The above method yielded the following results: cement clinker production of 25,000 t / d (300 operating days per year, annual output of 2 million tons), with quality meeting GB 175-2007 standards; annual low-carbon olefin production of 320,000 tons; and system carbon emissions reduced by 86% compared to traditional processes, resulting in annual emission reductions. Approximately 1.022 million tons; comprehensive energy consumption is reduced by 24% compared with traditional processes, saving approximately 910,000 tons of standard coal equivalent per year; the system thermal efficiency is 86.5%, the syngas conversion rate is 82%, and the low-carbon olefin selectivity is 73%.

[0130] 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 cement-chemical co-production system, characterized in that, include: An electrolysis water hydrogen production unit is used to electrolyze water to produce hydrogen and oxygen. The hydrogen is pressurized to 3.0-6.0 MPa, and the oxygen is used for oxygen-enriched combustion. A microwave-assisted hydrogenation and calcination unit is connected to the hydrogen outlet of the water electrolysis and hydrogen production unit. It is used to receive raw materials containing calcium carbonate and pressurized hydrogen and react them at 800-950℃ and 3.0-6.0 MPa to produce calcium oxide and synthesis gas containing carbon monoxide. The hydrogenation and calcination unit includes a microwave generator that generates 10-100 GHz microwaves. The cement clinker calcination unit is connected to the calcium oxide outlet of the microwave-assisted hydrogenation calcination unit and the oxygen outlet of the water electrolysis hydrogen production unit, and uses oxygen-enriched combustion technology to calcine the cement clinker. The syngas purification unit is connected to the syngas outlet of the microwave-assisted hydrogenation and calcination unit and is used to dehydrate, remove dust, deoxygenate, denitrify and desulfurize the syngas. The syngas proportioning unit, connected to the outlet of the syngas purification unit, is equipped with an online syngas analyzer and a hydrogen replenishment regulating valve for real-time monitoring. The system controls the CO concentration and automatically adjusts the hydrogen supply flow rate. Target ratio; A chemical synthesis unit is connected to the outlet of the synthesis gas proportioning unit and is used to convert the proportioned synthesis gas into high-value chemicals. The waste heat recovery unit is used to recover and recycle the waste heat generated by each unit. The automated control and data monitoring unit is communicatively connected to the water electrolysis hydrogen production unit, microwave-assisted hydrogenation calcination unit, cement clinker calcination unit, syngas purification unit, chemical synthesis unit, and waste heat recovery unit, respectively, and is used to monitor and adjust the system operating parameters in real time.

2. The cement-chemical co-production system according to claim 1, characterized in that, The water electrolysis hydrogen production unit includes a water source treatment device, an electrolyzer, and a hydrogen compressor. The water source treatment device sequentially prepares high-purity deionized water through a multi-media filter, an ultrafiltration device, a reverse osmosis device, and an electrodeionization device. The electrolyzer electrolyzes water to produce hydrogen and oxygen. The hydrogen compressor pressurizes the hydrogen to 3.0-6.0 MPa.

3. The cement-chemical co-production system according to claim 1, characterized in that, The microwave-assisted hydrogenation calcination unit includes a microwave resonant cavity, a hydrogenation calcination reactor, a gas distribution plate, and a heat exchange tube bundle. The hydrogenation calcination reactor is located inside the microwave resonant cavity, and the gas distribution plate is located at the bottom of the hydrogenation calcination reactor to ensure that the calcium carbonate particles are in full contact with hydrogen. The heat exchange tube bundle is used for waste heat recovery.

4. The cement-chemical co-production system according to claim 1, characterized in that, The cement clinker calcination unit includes a rotary kiln, a decomposition furnace, and a grate cooler. The oxygen-enriched combustion system of the rotary kiln controls the oxygen concentration to be 25-30%, the calcination temperature to be 1350-1450℃, and the calcination time to be 20-40 minutes.

5. The cement-chemical co-production system according to claim 1, characterized in that, The syngas purification unit includes a dehydration device, a dust removal device, a deoxygenation device, a denitrification device, and a desulfurization device connected in sequence. The purified syngas has a water content of <10 ppm, a dust content of <1 mg / Nm3, and a total sulfur content of <0.1 ppm.

6. The cement-chemical co-production system according to claim 1, characterized in that, The control method for the syngas proportioning unit includes: Real-time detection of syngas using an online analyzer and CO concentration; Calculate the current Proportion; The deviation value is obtained by comparing the current ratio with the target ratio. The opening degree of the hydrogen replenishment regulating valve is adjusted by a control algorithm; Feedforward control is performed based on the total syngas flow rate to adjust the hydrogen flow rate setpoint in advance.

7. The cement-chemical co-production system according to claim 1, characterized in that, The automated control and data monitoring unit includes a distributed control system and an artificial intelligence system. The distributed control system enables automatic control of each unit, and the artificial intelligence system includes a predictive maintenance module, an intelligent optimization module, and a safety diagnosis module.

8. The cement-chemical co-production system according to claim 7, characterized in that, The automated control and data monitoring unit performs the following control methods: The hydrogen pressure control loop maintains the reactor inlet hydrogen pressure within the set value ±0.1 MPa range; The reaction temperature control loop controls the reaction temperature within a set value of ±5℃ by adjusting the microwave power and the amount of cold hydrogen injected; the oxygen concentration control loop maintains the oxygen content at the kiln tail gas within the range of 1%-3% based on the oxygen content at the kiln tail gas.

9. The cement-chemical co-production system according to claim 1, characterized in that, The chemical synthesis unit employs a Fischer-Tropsch synthesis reactor, which is either a slurry bed or a fixed bed reactor, using cobalt-based or iron-based catalysts, with a reaction temperature of 200-250℃, a pressure of 2.0-3.0 MPa, a syngas conversion rate of ≥80%, and a target chemical selectivity of ≥70%.

10. A control method for a cement-chemical co-production system, employing the cement-chemical co-production system according to any one of claims 1-9, characterized in that, Includes the following steps: S1: Utilize renewable energy to generate electricity, and electrolyze water to produce hydrogen and oxygen through a water electrolysis hydrogen production unit. The hydrogen is pressurized to 3.0-6.0 MPa, and the oxygen is transported to the cement clinker calcination unit. S2: Raw materials containing calcium carbonate and pressurized hydrogen enter the microwave-assisted hydrogenation calcination unit, where they react under microwave assistance at 10-100 GHz at 800-950℃ and 3.0-6.0 MPa to produce calcium oxide and syngas; S3: Calcium oxide is fed into the cement clinker calcination unit and burned in oxygen-enriched combustion to produce cement clinker. S4: Syngas undergoes dehydration, dust removal, deoxygenation, denitrification and desulfurization treatment in sequence through the syngas purification unit; S5: The purified syngas enters the syngas proportioning unit, which is monitored in real time. The system automatically adjusts the hydrogen supply flow rate based on CO concentration to control... The proportion has reached the target value; S6: The blended syngas is sent to the chemical synthesis unit and converted into high-value chemicals; S7: Waste heat from each unit is recovered through the waste heat recovery unit and used for raw material drying, equipment heating or power generation; S8: The system operating parameters are monitored and adjusted in real time through the automated control and data monitoring unit to ensure stable and efficient system operation.

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