Energy-saving and carbon-reducing process for raw coal

Abstract

The invention relates to the technical field of modern coal chemical industry, and discloses an energy-saving and carbon-reducing process for raw coal, which comprises the following steps: step 1, raw material treatment: waste collection and pretreatment; step 2, classification detection: classifying the taken RDF alternative fuel samples according to types; step 3, sampling detection: establishing an incoming RDF alternative fuel sampling detection system, and carrying out sampling detection on chloride ions, total chromium and a heat value on the incoming fuel of each vehicle; 4, optimizing and adjusting the fuel proportion: replacing the fuel blending proportion through the screened RDF, and then introducing an intelligent control system to monitor the combustion state and heat value output in real time; step five, production process optimization: a chloride ion regulation and control and kiln preheater optimization process and a total chromium content control and hexavalent chromium conversion inhibition process are included; through a chloride ion removal process and in combination with a real-time monitoring and intelligent feedback regulation system, the content of chloride ions in the RDF alternative fuel can be accurately controlled, and the problems that the kiln preheater crusts and the content of chloride ions in clinker exceeds the standard are effectively prevented.

Description

Technical Field

[0001] The invention relates to the technical field of modern coal chemical industry, and in particular to a raw coal energy-saving and carbon-reducing process. Background Art

[0003] Currently, the price of raw coal, the main fuel in cement production, continues to rise, directly pushing up the cost of clinker production, accounting for about one-third of the total cost. This not only increases the operating burden of enterprises, but also limits their competitiveness in the market. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the shortcomings of the prior art, the present invention provides a raw coal energy-saving and carbon-reducing process, which has the advantages of environmental protection, low carbon, low cost and low consumption, and solves the problems that a large amount of carbon dioxide will be generated in the raw coal combustion process, causing environmental pollution, and the high cost and high consumption of raw coal.

[0006] (II) Technical solution

[0007] To achieve the above object, the present invention provides the following technical solution: a raw coal energy-saving and carbon reduction process, comprising the following steps:

[0008] Step 1. Raw material processing: waste collection and pretreatment;

[0009] Step 2: Classification and testing: Classify the retrieved RDF alternative fuel samples according to their types;

[0010] Step 3: Sampling and testing: Establish a sampling and testing system for RDF alternative fuels entering the factory, and conduct sampling and testing of chloride ions, total chromium and calorific value on each truck of fuel entering the factory;

[0011] Step 4: Optimize and adjust the fuel ratio: select the RDF alternative fuel blending ratio, and then introduce an intelligent control system to monitor the combustion status and calorific value output in real time;

[0012] Step 5: Optimize production process: including chloride ion regulation and kiln preheater optimization process, total chromium content control and hexavalent chromium conversion inhibition process.

[0013] Preferably, the raw material processing in step 1 is:

[0014] S1.1. Waste collection: waste cloth, waste plastic, pine needles, cotton cloth, sponge and leather are collected as RDF alternative fuel for cement production;

[0015] S1.2 Pretreatment: Preliminary treatment of the collected waste, such as crushing, cleaning and drying.

[0016] Preferably, the classification detection process in step 2:

[0017] S2.1. Classification: The retrieved RDF alternative fuel samples are classified in detail according to different types. Waste cloth and cotton belong to the textile category; waste plastic belongs to the plastic category; pine needles belong to the plant fiber category; sponges belong to the synthetic material category; leather belongs to the animal fiber category;

[0018] S2.2. Preliminary testing: Determine the moisture content of the classified samples and set the safety threshold of the moisture content below 10%.

[0019] Preferably, the sampling detection process in step 3:

[0020] S3.1, Stratified sampling: Divide the incoming fuel of each vehicle into four vertical columns;

[0021] S3.2. Multi-height sampling: Take samples at 5cm*10cm, 5cm*30cm, 5cm*60cm and 5cm*100cm above the bottom of each vertical column for sampling and testing of chloride ions, total chromium and calorific value.

[0022] Preferably, the harmful substances and calorific value control process in step 4 is:

[0023] S4.1. Return or environmentally friendly recycling: Based on the test results, the RDF alternative fuel samples with excessive harmful substances and poor calorific value estimation will be returned or environmentally friendly recycled;

[0024] S4.2. Adjust the blending ratio: adjust the blending ratio of the screened RDF alternative fuel, and combine it with a calorific value enhancer to increase the calorific value of the RDF alternative fuel;

[0025] S4.3. Introduce intelligent control system: real-time monitoring of combustion status and calorific value output, automatic adjustment of combustion parameters;

[0026] S4.4. Data analysis and prediction model: to achieve early prediction and effective response to calorific value fluctuations.

[0027] Preferably, the harmful substances and their exceeding standard values ​​in S4.1 are: chloride ion content greater than 0.6%, and total chromium content greater than 300 mg / kg.

[0028] Preferably, in the calorific value estimation in S4.1: the calorific value of the RDF alternative fuel sample is measured and estimated using an oxygen bomb calorimeter, and the calorific value enhancer in S4.2 is iron slag and carbide slag in a weight ratio of 3:1.

[0029] Preferably, the production process is optimized in step 5:

[0030] S5.1. Chloride ion control and kiln preheater optimization process: Combine real-time monitoring and intelligent feedback regulation system to control the chloride ion content in RDF alternative fuel;

[0031] S5.2. Total chromium content control and hexavalent chromium conversion inhibition process: Use stabilizing additives to reduce the hexavalent chromium content.

[0032] Preferably, in S5.1, an ion selective electrode is used to monitor the chloride ion content in the RDF alternative fuel entering the factory in real time. Based on the real-time monitoring data, an intelligent control system is set to automatically adjust the excess air coefficient and the combustion temperature, and the chemical precipitation method and the adsorption method are combined to further reduce the chloride ion content in the RDF alternative fuel.

[0033] Preferably, calcium phosphate and calcium sulfate are added as stabilizing additives in a weight ratio of 2:1 in S5.2.

[0034] Compared with the prior art, the present invention provides a raw coal energy-saving and carbon-reducing process, which has the following beneficial effects:

[0035] 1. The present invention can accurately control the chloride ion content in the RDF alternative fuel through the chloride ion removal process, combined with real-time monitoring and intelligent feedback adjustment system, effectively prevent the kiln preheater from crusting and excessive chloride ion content in the clinker. At the same time, the kiln preheater design is optimized, which helps to enhance its anti-scaling ability and ensure stable production operation.

[0036] 2. The present invention implements source screening and pretreatment strategies through total chromium content control and hexavalent chromium conversion inhibition technology, reduces the mixing of high-chromium raw materials, and reduces the hexavalent chromium content through stabilizing additives, which can further inhibit the formation of hexavalent chromium during the combustion process and ensure the quality of clinker. At the same time, the optimized combustion process can also reduce hexavalent chromium emissions while meeting environmental protection requirements.

[0037] 3. The present invention uses intelligent control technology for calorific value enhancement and stabilization to screen high calorific value components and optimize the ratio, combined with the addition of calorific value enhancers, which helps to improve the calorific value of RDF alternative fuels. At the same time, the introduction of an intelligent control system helps to monitor the combustion state and calorific value output in real time, thereby automatically adjusting the combustion parameters to maintain a stable and efficient combustion process. Finally, through data analysis and prediction models, early prediction and effective response to calorific value fluctuations can be achieved to ensure maximum production benefits.

[0038] 4. The present invention uses waste cloth, waste plastic, pine needles, cotton cloth, sponge and leather as RDF alternative fuel for cement production, thereby solving the problems of large amount of carbon dioxide generated in the combustion process of raw coal causing environmental pollution, and high cost and large consumption of raw coal. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] See also Figure 1 , a raw coal energy-saving and carbon-reducing process, comprising the following steps:

[0042] Step 1. Raw material processing: waste collection and pretreatment;

[0043] Step 2: Classification and testing: Classify the retrieved RDF alternative fuel samples according to their types;

[0044] Step 3: Sampling and testing: Establish a sampling and testing system for RDF alternative fuels entering the factory, and conduct sampling and testing of chloride ions, total chromium and calorific value on each truck of fuel entering the factory;

[0045] Step 4: Optimize and adjust the fuel ratio: Through the selected RDF alternative fuel blending ratio (conduct statistical analysis on sampling test data, evaluate the applicability of different types of alternative fuels, select high-quality alternative fuels suitable for the company's production process, continuously adjust the RDF alternative fuel matching ratio, optimize combustion performance, reduce the content of harmful substances, and improve calorific value utilization), then introduce an intelligent control system to monitor the combustion state and calorific value output in real time;

[0046] Step 5: Optimize production process: including chloride ion regulation and kiln preheater optimization process, total chromium content control and hexavalent chromium conversion inhibition process.

[0047] Specifically, evaluate and provide feedback on the effects of steps one to five above: regularly evaluate the effects of alternative fuel use, including coal consumption reduction, product quality stability, and environmental impact.

[0048] Specifically, the raw material processing in step 1:

[0049] S1.1. Waste collection: waste cloth, waste plastic, pine needles, cotton, sponge and leather are collected as RDF alternative fuel for cement production;

[0050] S1.2 Pretreatment: Preliminary treatment of the collected waste, such as crushing, cleaning and drying, to improve its combustion efficiency and quality.

[0051] Specifically, the classification detection process in step 2:

[0052] S2.1. Classification: The retrieved RDF alternative fuel samples are classified in detail according to different types. Waste cloth and cotton belong to the textile category; waste plastic belongs to the plastic category; pine needles belong to the plant fiber category; sponges belong to the synthetic material category; leather belongs to the animal fiber category;

[0053] S2.2, Preliminary testing: Determine the moisture content of the classified samples and set the safety threshold of the moisture content below 10%. This step determines whether the RDF alternative fuel samples need to be secondary dried to prepare for the next step.

[0054] Specifically, the chloride ion control and kiln preheater optimization process: Combine real-time monitoring and intelligent feedback adjustment system to control the chloride ion content in the RDF alternative fuel, use ion selective electrodes to monitor the chloride ion content in the RDF alternative fuel entering the factory in real time, and combine the real-time monitoring data to set up an intelligent control system to automatically adjust the excess air coefficient and combustion temperature to reduce the emission concentration of chloride ions. Combine the chemical precipitation method and the adsorption method to further reduce the chloride ion content in the RDF alternative fuel, thereby effectively preventing the kiln preheater crusting and excessive chloride ion content in the clinker.

[0055] Example 1

[0056] Sampling testing process:

[0057] Stratified sampling: Divide each truckload of incoming fuel into four vertical columns. This stratified method helps obtain samples at different levels, thus providing a more comprehensive understanding of the properties of the entire batch of fuel;

[0058] Multi-height sampling: Sampling is performed at 5cm*10cm, 5cm*30cm, 5cm*60cm and 5cm*100cm above the bottom of each vertical column for spot testing of chloride ions, total chromium and calorific value. This multi-height sampling can take into account the differences in fuel at different depths.

[0059] Comparative Example 1

[0060] Sampling testing process:

[0061] Samples are taken from 5cm*10cm, 5cm*30cm, 5cm*60cm and 5cm*100cm above the bottom of each truckload of incoming fuel for random testing of chloride ions, total chromium and calorific value. Such multi-height sampling can take into account the differences in fuel at different depths.

[0062] Take one set of data for analysis and comparison, the data is as follows Table 1:

[0063] Table 1

[0064] Sampling Method Chloride ion (mg / L) Total chromium (mg / L) Calorific value (kJ / kg) Example 1 100±10 5.0±0.5 18000±500 Comparative Example 1 120±15 5.5±0.7 17500±600

[0065] As can be seen from Table 1, the measurement results of Example 1 show lower variability in chloride ion and calorific value, which is because its sampling method can better reflect the uniformity of the entire batch of fuel, while the results of Comparative Example 1 have a larger variability, which is due to the sampling method being not comprehensive enough, resulting in insufficient representativeness of the results.

[0066] Example 2

[0067] Return or environmentally friendly recycling: Based on the test results, the retrieved RDF alternative fuel samples with excessive harmful substances (harmful substances and their excessive values ​​are: chloride ion content greater than 0.6%, total chromium content greater than 300 mg / kg) and poor calorific value estimation (calorific value estimation: use an oxygen bomb calorimeter to measure and estimate the calorific value of RDF alternative fuel samples) will be returned or recycled in an environmentally friendly manner.

[0068] Comparative Example 2

[0069] The product will proceed directly to the next stage without being returned or recycled.

[0070] Table 2

[0071]

[0072]

[0073] Table 2 provides information on the different strategies and potential impacts of Example 2 and Comparative Example 2 in processing RDF alternative fuel samples. Example 2 processes the excessive fuel by return or environmental recycling. Although it increases the processing cost and time, it can ensure the quality of the fuel and reduce the impact on the environment. It is suitable for occasions with high requirements on fuel quality. Comparative Example 2 directly enters the next stage, saving processing time, but there will be unstable fuel quality and environmental risks. It is suitable for occasions with low requirements on fuel quality.

[0074] Example 3

[0075] Adjust the blending ratio: adjust the blending ratio of the screened RDF alternative fuel, and combine it with a calorific value enhancer (the calorific value enhancer is iron slag and carbide slag in a weight ratio of 3:1) to improve the calorific value of the RDF alternative fuel;

[0076] Comparative Example 3

[0077] Adjust the blending ratio: adjust the blending ratio of the screened RDF alternative fuel to increase the calorific value of the RDF alternative fuel;

[0078]

[0079] From the analysis of Table 3, we can get:

[0080] Example 3 improves the calorific value of RDF alternative fuel by adding a calorific value enhancer (iron slag and carbide slag are mixed in a ratio of 3:1). Carbide slag is an industrial waste residue containing a large amount of calcium hydroxide, which has high reactivity and can be used as an excellent secondary calcium-based resource for building material preparation. It also meets environmental protection requirements, and the mixed use of iron slag and carbide slag helps to improve the calorific value and combustion performance of RDF. Comparative Example 3 does not use a calorific value enhancer, but improves the calorific value of RDF alternative fuel by adjusting the blending ratio, which results in low combustion efficiency.

[0081] Example 4

[0082] Introducing intelligent control system: real-time monitoring of combustion status and calorific value output, automatic adjustment of combustion parameters to maintain a stable and efficient combustion process;

[0083] Data analysis and prediction model: to achieve early prediction and effective response to calorific value fluctuations to ensure maximum production efficiency.

[0084] Chloride ion control and kiln preheater optimization process: Combined with real-time monitoring and intelligent feedback regulation system, the chloride ion content in RDF alternative fuel is controlled, thereby effectively preventing kiln preheater crusting and excessive chloride ion content in clinker.

[0085] Comparative Example 4

[0086] No intelligent control system was introduced and the combustion process was carried out according to traditional process methods.

[0087] Table 4

[0088]

[0089] Example 4 introduces an intelligent control system, which can monitor the combustion state and calorific value output in real time, and automatically adjust the combustion parameters to maintain a stable and efficient combustion process. This intelligent control method can achieve early prediction and effective response to calorific value fluctuations, thereby ensuring the maximization of production benefits, and the intelligent control system also helps to reduce pollutant emissions, improve energy efficiency, and reduce costs. Comparative Example 4 uses a traditional process method without introducing an intelligent control system. This method relies on periodic detection or the operator's experience to adjust the combustion parameters, which will have lags and inaccuracies. Due to the difficulty in predicting calorific value fluctuations, the response measures will not be timely, resulting in production benefits that may be limited by the instability of combustion efficiency. In addition, this method will result in low energy efficiency, high costs, and increased pollutant emissions due to insufficient combustion or improper control.

[0090] Example 5

[0091] Total chromium content control and hexavalent chromium conversion inhibition process: Use stabilizing additives (calcium phosphate and calcium sulfate in a weight ratio of 2:1 as stabilizing additives) to reduce the hexavalent chromium content, further inhibit the formation of hexavalent chromium during the combustion process, and ensure the quality of clinker.

[0092] Comparative Example 5

[0093] Total chromium content control and hexavalent chromium conversion inhibition process: No stabilization additives are used to reduce the hexavalent chromium content.

[0094] In order to compare Example 5 with Comparative Example 5, a factory measured the total chromium content and hexavalent chromium content under the two processes in different time periods. The result data are shown in Table 5:

[0095] Table 5

[0096]

[0097] Note: Time point: the specific time of monitoring, from the beginning to 24 hours later; Total chromium content: the total chromium concentration at each time point, in mg / kg; Hexavalent chromium content: the hexavalent chromium concentration at each time point, in mg / kg.

[0098] It can be seen from Table 5 above that the total chromium content and hexavalent chromium content of Example 5 using the stabilizing additive at each time point are lower than those of Comparative Example 5 not using the stabilizing additive, indicating that the stabilizing additive effectively reduces the formation of hexavalent chromium and inhibits its further conversion, thereby ensuring the quality of the clinker, and this effect becomes more obvious over time, showing the long-term effectiveness of the stabilizing additive.

[0099] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A raw coal energy-saving and carbon-reducing process, characterized in that: The following steps are involved: Step 1. Raw material processing: waste collection and pretreatment; Step 2: Classification and testing: Classify the retrieved RDF alternative fuel samples according to their types; Step 3: Sampling and testing: Establish a sampling and testing system for RDF alternative fuels entering the factory, and conduct sampling and testing of chloride ions, total chromium and calorific value on each truck of fuel entering the factory; Step 4: Optimize and adjust the fuel ratio: select the RDF alternative fuel blending ratio, and then introduce an intelligent control system to monitor the combustion status and calorific value output in real time; Step 5: Optimize production process: including chloride ion regulation and kiln preheater optimization process, total chromium content control and hexavalent chromium conversion inhibition process.

2. The process for energy saving and carbon reduction of raw coal according to claim 1, characterized in that: Raw material processing in step 1: S1.

1. Waste collection: waste cloth, waste plastic, pine needles, cotton, sponge and leather are collected as RDF alternative fuel for cement production; S1.2 Pretreatment: Preliminary treatment of the collected waste, such as crushing, cleaning and drying.

3. A raw coal energy-saving and carbon-reducing process according to claim 2, characterized in that: The classification detection process in step 2: S2.

1. Classification: The retrieved RDF alternative fuel samples are classified in detail according to different types. Waste cloth and cotton belong to the textile category; waste plastic belongs to the plastic category; pine needles belong to the plant fiber category; sponges belong to the synthetic material category; leather belongs to the animal fiber category; S2.

2. Preliminary testing: Determine the moisture content of the classified samples and set the safety threshold of the moisture content below 10%.

4. The process for energy saving and carbon reduction of raw coal according to claim 1, characterized in that: The sampling and testing process in step 3: S3.1, Stratified sampling: Divide the incoming fuel of each vehicle into four vertical columns; S3.

2. Multi-height sampling: Take samples at 5cm*10cm, 5cm*30cm, 5cm*60cm and 5cm*100cm above the bottom of each vertical column for sampling and testing of chloride ions, total chromium and calorific value.

5. The process for energy saving and carbon reduction of raw coal according to claim 1, characterized in that: The harmful substances and calorific value control process in step 4: S4.

1. Return or environmentally friendly recycling: Based on the test results, the RDF alternative fuel samples with excessive harmful substances and poor calorific value estimation will be returned or environmentally friendly recycled; S4.

2. Adjust the blending ratio: adjust the blending ratio of the screened RDF alternative fuel, and combine it with a calorific value enhancer to increase the calorific value of the RDF alternative fuel; S4.

3. Introduce intelligent control system: real-time monitoring of combustion status and calorific value output, automatic adjustment of combustion parameters; S4.

4. Data analysis and prediction model: to achieve early prediction and effective response to calorific value fluctuations.

6. A raw coal energy-saving and carbon-reducing process according to claim 5, characterized in that: The harmful substances and their exceeding standard values ​​in S4.1 are: chloride ion content greater than 0.6%, and total chromium content greater than 300 mg / kg.

7. The process for energy saving and carbon reduction of raw coal according to claim 5, characterized in that: Calorific value estimation in S4.1: the calorific value of the RDF alternative fuel sample is measured and estimated using an oxygen bomb calorimeter, and the calorific value enhancer in S4.2 is iron slag and carbide slag in a weight ratio of 3:

1.

8. The process for energy saving and carbon reduction of raw coal according to claim 1, characterized in that: Optimize the production process in step 5: S5.

1. Chloride ion control and kiln preheater optimization process: Combine real-time monitoring and intelligent feedback regulation system to control the chloride ion content in RDF alternative fuel; S5.

2. Total chromium content control and hexavalent chromium conversion inhibition process: Use stabilizing additives to reduce the hexavalent chromium content.

9. A raw coal energy-saving and carbon-reducing process according to claim 8, characterized in that: In the S5.1, an ion selective electrode is used to monitor the chloride ion content in the RDF alternative fuel entering the factory in real time. Based on the real-time monitoring data, an intelligent control system is set to automatically adjust the excess air coefficient and the combustion temperature, and the chemical precipitation method and the adsorption method are combined to further reduce the chloride ion content in the RDF alternative fuel.

10. The process for energy saving and carbon reduction of raw coal according to claim 8, characterized in that: In the S5.2, calcium phosphate and calcium sulfate are added in a weight ratio of 2:1 as stabilizing additives.

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