Extraction amount regulation and control method based on distillation range analysis

Abstract

The invention discloses an extraction amount regulation and control method based on distillation range analysis, and relates to the technical field of petroleum processing, and the method comprises the following steps: based on historical distillation range adjustment data, obtaining a fraction product yield before distillation range adjustment and a distillation volume percentage before and after distillation range adjustment, and according to the data obtained in the step 1, determining the extraction amount of the fraction product; calculating a yield adjustment value for current distillation range adjustment and adjusting operation parameters of the fractionation system based on the yield adjustment value calculated in the step 2 to enable the yield of the fraction product in the current distillation range adjustment process to reach a target yield; according to the method, the dynamic mapping model of the fraction cutting point and the temperature gradient is established by utilizing a distillation range analysis technology, and the operation parameters of the fractionation system are rectified by analyzing the influence rule of different distillation range intervals on the extraction amount of the intermediate product, so that the yield of the fraction product in the current distillation range adjustment process reaches the target yield; the flexible adjustment of the diesel oil / gasoline output ratio is realized, the yield of high-added-value products can be improved, and the inventory overstock risk is reduced.

Description

Technical Field

[0001] This invention relates to the field of petroleum processing technology, and in particular to a method for controlling the extraction rate based on distillation range analysis. Background Technology

[0002] Heavy traffic asphalt units are important equipment in the petroleum processing industry used to extract and process crude oil and produce asphalt for heavy traffic roads. After desalting and dehydration, the crude oil is heated to a suitable temperature through a heat exchanger. The feedstock then enters an atmospheric distillation tower for preliminary fractionation. The top of the tower produces light components such as gasoline, kerosene, and diesel. The bottom residue is heated in a vacuum furnace and then enters a vacuum distillation tower for further separation of wax oil and residual oil. The bottom residue is then processed through oxidation, blending, and other processes to adjust the component ratios, ultimately producing heavy traffic asphalt that meets the standards.

[0003] With the increase in the capacity of heavy-duty asphalt plants, traditional production models, relying on fixed process parameters, are struggling to adapt to fluctuations in feedstock composition and changes in market demand. Currently, refineries generally face the problem of rigidly fixed proportions of finished products such as diesel and gasoline. For example, the correlation between distillation range parameters and intermediate product extraction rates during crude oil cracking lacks dynamic modeling, causing product structure adjustments to lag behind market cycles. Especially against the backdrop of intensified fluctuations in the asphalt market supply and demand, the inability to optimize fractionation tower operations in real time through distillation range characteristics will result in losses in high-value-added product yields and inventory buildup. Therefore, this invention proposes an extraction rate control method based on distillation range analysis to address the shortcomings of existing technologies. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a method for adjusting the extraction rate based on distillation range analysis. By utilizing distillation range analysis technology to establish a dynamic mapping model between the fraction cut-off point and the temperature gradient, and by analyzing the influence of different distillation ranges on the extraction rate of intermediate products, the operating parameters of the fractionation system are adjusted to ensure that the fraction product output during the current distillation range adjustment process reaches the target output. This achieves flexible adjustment of the diesel / gasoline production ratio, which can improve the yield of high value-added products and reduce the risk of inventory backlog.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for controlling extraction rate based on distillation range analysis includes the following steps: Step 1: Based on historical distillation range adjustment data, obtain the fraction product yield before distillation range adjustment and the distillate volume percentage before and after distillation range adjustment; Step 2: Based on the data obtained in Step 1, calculate the production adjustment value for the current distillation range; Step 3: Based on the production adjustment value calculated in Step 2, adjust the operating parameters of the fractionation system so that the production of the fraction product in the current distillation range adjustment process reaches the target production.

[0006] A further improvement is that: the step one of obtaining the distillation volume percentage before and after the distillation range adjustment specifically includes: obtaining the first distillation volume percentage corresponding to the distillation temperature before the distillation range adjustment and obtaining the second distillation volume percentage corresponding to the distillation temperature after the distillation range adjustment.

[0007] A further improvement is made in that, in step one, when obtaining the output of the distillate product before the distillation range adjustment, data is collected by high-precision flow meters installed on each distillate product pipeline.

[0008] A further improvement is made in the following step: when obtaining the first distillate volume percentage corresponding to the distillation temperature before distillation range adjustment and the second distillate volume percentage corresponding to the distillation temperature after distillation range adjustment in step one, temperature sensors set at different heights of the fractionation column are used to monitor the temperature changes at each tray or side stream extraction position. Then, based on the standard distillation range analysis method, the first distillate volume percentage and the second distillate volume percentage are obtained.

[0009] The further improvement lies in the following: before obtaining the fraction product yield before distillation adjustment and the distillation volume percentage before and after distillation adjustment based on historical distillation range adjustment data in step one, the data preprocessing of historical distillation range adjustment data is also included, specifically: data cleaning, data transformation, data integration, data reduction and data verification of historical distillation range adjustment data.

[0010] A further improvement is made in step two, where the yield adjustment value for the current distillation range is calculated. The distillation temperature before the range adjustment is set to T1, with the corresponding first distillation volume percentage being V1%. The distillation temperature after the range adjustment is set to T2, with the corresponding second distillation volume percentage being V2%. For a specific fraction, the yield before the range adjustment is Q1, the total feed volume is F, and according to the definition of distillation volume percentage, the theoretical content of this fraction in the feed is V1%, and after adjustment it is V2%. The yield adjustment value ΔQ for the fraction can be expressed as: ΔQ = F × (V2% - V1%) Introducing a correction factor k, the adjusted production value ΔQ for the distillate product is: ΔQ' = ΔQ × k A further improvement is made in step three, which involves adjusting the operating parameters of the fractionation system by constructing a dynamic matrix control (DMC) model for the fractionation tower, incorporating the variables in the operating parameters into the control loop, and calculating the optimal combination of operating parameters every 5 minutes through a rolling optimization strategy.

[0011] A further improvement is made in step three, where variables in the operating parameters are incorporated into the control loop. This involves analyzing the key operating parameters in the fractionation system that affect the yield of the distillate products, and then determining the quantitative relationship between each parameter and the yield of the distillate products to form a digital model.

[0012] A further improvement is made in step three, when analyzing the key operating parameters affecting the yield of distillate products in the fractionation system, using sensitivity analysis to determine the degree of influence of the parameters on the yield of distillate products, and prioritizing the adjustment of parameters with a greater degree of influence.

[0013] The further improvement lies in the following: In step three, the operating parameters of the fractionation system are gradually changed by gradient adjustment. During the parameter adjustment process, the yield and quality of the fraction products and various operating parameters of the fractionation system are monitored in real time, and the adjustment effect is recorded in a timely manner.

[0014] The beneficial effects of this invention are as follows: This invention focuses on the coupling mechanism between the feedstock distillation range characteristics and the fractionation process of heavy-duty asphalt plants. It uses distillation range analysis technology to establish a dynamic mapping model between the fractionation cut-off point and the temperature gradient. By analyzing the influence of different distillation ranges on the extraction of intermediate products, the operating parameters of the fractionation system are adjusted to ensure that the fraction product output in the current distillation range adjustment process reaches the target output. This achieves flexible adjustment of the diesel / gasoline production ratio, which can improve the yield of high value-added products, reduce the risk of inventory backlog, and enhance the overall economic benefits and market competitiveness of heavy-duty asphalt plants. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the method flow of the present invention. Detailed Implementation

[0016] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0017] according to Figure 1 As shown, this embodiment proposes a method for adjusting the extraction rate based on distillation range analysis, including the following steps: Step 1: Perform data cleaning, transformation, integration, reduction, and verification on historical distillation range adjustment data. Then, based on the historical distillation range adjustment data, collect data using high-precision flow meters installed on each fraction product pipeline. The collected fraction product yield data before distillation range adjustment is calibrated in conjunction with changes in tank farm inventory to ensure the accuracy and reliability of the collected fraction product yield data before distillation range adjustment. When obtaining the first distillation volume percentage corresponding to the distillation temperature before distillation range adjustment and the second distillation volume percentage corresponding to the distillation temperature after distillation range adjustment, temperature sensors installed at different heights of the fractionation column are used to monitor temperature changes at each tray or side stream extraction position. Then, based on standard distillation range analysis methods, obtain the first distillation volume percentage and the second distillation volume percentage.

[0018] Step 2: Based on the data obtained in Step 1, calculate the production adjustment value for the current distillation range; Let the distillation temperature before range adjustment be T1, with a corresponding first distillate volume percentage of V1%, and the distillation temperature after range adjustment be T2, with a corresponding second distillate volume percentage of V2%. For a specific fraction, its yield before range adjustment is Q1, the total feed volume is F, and according to the definition of distillate volume percentage, the theoretical content of this fraction in the feed is V1%, and after adjustment it is V2%. The yield adjustment value ΔQ for the fraction can be expressed as: ΔQ = F × (V2% - V1%) Introducing a correction factor k, the adjusted production value ΔQ for the distillate product is: ΔQ' = ΔQ × k.

[0019] Step 3: Based on the production adjustment value calculated in Step 2, adjust the operating parameters of the fractionation system so that the production of the distillate product in the current distillation range adjustment process reaches the target production. This includes constructing a dynamic matrix control (DMC) model for the distillation tower, incorporating variables from the operating parameters into the control loop, and calculating the optimal combination of operating parameters every 5 minutes through a rolling optimization strategy; When the variables in the operating parameters are incorporated into the control loop, the key operating parameters affecting the yield of distillate products in the fractionation system are analyzed, and then the quantitative relationship between each parameter and the yield of distillate products is determined to form a digital model. When analyzing the key operating parameters affecting the yield of distillate products in a fractionation system, sensitivity analysis is used to determine the degree of influence of the parameters on the yield of distillate products, and parameters with a greater degree of influence are adjusted first. The operating parameters of the fractionation system are gradually changed using a gradient adjustment method. During the parameter adjustment process, the yield and quality of the fraction products and various operating parameters of the fractionation system are monitored in real time, and the adjustment effect is recorded in a timely manner.

[0020] Taking a 1 million tonnes / year heavy asphalt unit in a refinery as an example, the production process faces challenges such as fluctuations in feedstock composition (e.g., crude oil API gravity varying between 25 and 32) and dynamic adjustments in market demand for diesel and gasoline (fluctuating between 1.5:1 and 2.5:1). Traditional fixed-parameter production methods result in rigid product ratios, failing to respond promptly to market changes and leading to low yields of high-value-added products (e.g., diesel yield below 65%) and inventory backlogs (diesel inventory reaching up to 30,000 tons). To address these issues, a distillation range analysis-based extraction rate control method is employed for production optimization.

[0021] Step 1: Install high-precision mass flow meters (accuracy ±0.1%) on each distillate product (diesel, gasoline, etc.) pipeline to collect real-time distillate product output data before and after distillation range adjustment. For example, before a certain distillation range adjustment, the diesel output Q1 was 60 tons / hour and the gasoline output was 30 tons / hour.

[0022] Distillate volume percentage data acquisition: Temperature sensors (accuracy ±0.5℃) were installed at different heights of the fractionation column (a total of 10 monitoring points) to monitor temperature changes at each tray or side stream extraction point. The distillate was analyzed using a laboratory distillation range analyzer. Before range adjustment, at a distillation temperature T1 = 250℃, the corresponding first distillate volume percentage V1% = 40%. After range adjustment, at a distillation temperature T2 = 260℃, the corresponding second distillate volume percentage V2% = 45%. The total feed throughput F = 100 tons / hour.

[0023] Step Two: Based on the formula ΔQ=F×(V2%−V1%), the theoretical production adjustment value ΔQ=100×(45%−40%)=5 tons / hour is calculated. Then, the impact of crude oil quality (sulfur content, density, etc.) and equipment operating status (fractionation tower tray efficiency, heat exchanger heat exchange efficiency, etc.) on production adjustment is considered. For example, when the sulfur content of crude oil increases by 1%, the output of distillate products may decrease by 0.5%. Through historical data regression analysis, a mathematical model of the correction coefficient k and each influencing factor is established, and the correction coefficient k is calculated to be 0.95. The corrected production adjustment value is calculated as follows: ΔQ′=ΔQ×k=5×0.95=4.75 tons / hour. That is, after considering various influencing factors, the actual production adjustment required is 4.75 tons / hour.

[0024] Step 3: Using orthogonal experimental design, sensitivity analysis was conducted on key operating parameters of the fractionation column, including feed temperature, feed rate, reflux ratio, top pressure, and bottom temperature, to determine the degree of influence of each parameter on the distillate product yield, as shown in the table below: Table 1

[0025] The operating parameters of the fractionation system are gradually changed using a gradient adjustment method. For example, the feed temperature is set to be adjusted by no more than 2°C each time, and the feed rate is set to be adjusted by no more than 1 ton / hour each time. During the parameter adjustment process, the yield and quality of the fraction products (such as the cetane number of diesel and the octane number of gasoline) and various operating parameters of the fractionation system (such as the top pressure and bottom temperature of the column) are monitored in real time, and the adjustment effect is recorded in a timely manner.

[0026] This invention focuses on the coupling mechanism between the feedstock distillation range characteristics and fractionation process of heavy-duty asphalt plants. It utilizes distillation range analysis technology to establish a dynamic mapping model between the fraction cut-off point and the temperature gradient. By analyzing the influence of different distillation ranges on the extraction of intermediate products, the operating parameters of the fractionation system are adjusted to ensure that the fraction product output during the current distillation range adjustment process reaches the target output. This enables flexible adjustment of the diesel / gasoline production ratio, which can improve the yield of high-value-added products, reduce the risk of inventory backlog, and enhance the overall economic benefits and market competitiveness of heavy-duty asphalt plants.

[0027] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A distillation range analysis-based extraction amount regulation method characterized by comprising: The method comprises the following steps: Step 1: based on historical distillation range adjustment data, obtaining the distillate product yield before distillation range adjustment and the distillation volume percentage before and after distillation range adjustment; Step 2: according to the data obtained in step 1, calculating the yield adjustment value for the current distillation range adjustment; Step 3: based on the yield adjustment value calculated in step 2, adjusting the operating parameters of the fractionation system to make the distillate product yield of the current distillation range adjustment process reach the target yield.

2. The method according to claim 1, wherein the method is characterized by: In step 1, the distillation volume percentage before and after distillation range adjustment is obtained, specifically including: obtaining the first distillation volume percentage corresponding to the distillation temperature before distillation range adjustment and obtaining the second distillation volume percentage corresponding to the distillation temperature after distillation range adjustment.

3. The method according to claim 2, wherein the method is characterized by: In step 1, when obtaining the distillate product yield before distillation range adjustment, data is collected through high-precision flow meters installed on each distillate product pipeline.

4. The method according to claim 2, wherein: In step 1, when obtaining the first distillation volume percentage corresponding to the distillation temperature before distillation range adjustment and the second distillation volume percentage corresponding to the distillation temperature after distillation range adjustment, temperature sensors arranged at different heights of the fractionation tower are used to monitor the temperature changes of each tray or side line extraction position, and then based on the standard distillation range analysis method, the first distillation volume percentage and the second distillation volume percentage are obtained.

5. The method of claim 1, wherein the method is based on distillation range analysis. Before the operation of step 1, the historical distillation range adjustment data is preprocessed, specifically including data cleaning, data conversion, data integration, data reduction and data verification.

6. The method of claim 1, wherein the method is based on distillation range analysis. In step 2, when calculating the yield adjustment value for the current distillation range adjustment, the distillation temperature before distillation range adjustment is set as T1, the corresponding first distillation volume percentage is V1%, the distillation temperature after distillation range adjustment is T2, the corresponding second distillation volume percentage is V2%, for a specific distillate product, the yield before distillation range adjustment is Q1, the total processing capacity of the raw material is F, according to the definition of the distillation volume percentage, the theoretical content of the distillate in the raw material is V1% before adjustment and V2% after adjustment, the yield adjustment value ΔQ of the distillate product can be expressed as: ΔQ = F × (V2% - V1%) A correction coefficient k is introduced, and the corrected yield adjustment value of the distillate product is: ΔQ' = ΔQ × k.

7. The method of claim 1, wherein the method is based on distillation range analysis. In step 3, when adjusting the operating parameters of the fractionation system, a fractionation tower dynamic matrix control (DMC) model is constructed, the variables in the operating parameters are included in the control loop, and the optimal operating parameter combination is calculated once every 5 minutes through a rolling optimization strategy.

8. The method according to claim 7, wherein the method is characterized by: In step 3, when the variables in the operating parameters are included in the control loop, the key operating parameters affecting the yield of the distillate product in the fractionation system are analyzed, and then the quantitative relationship between each parameter and the yield of the distillate product is determined to form a digital model.

9. The method according to claim 8, wherein the method is characterized by: In step 3, when analyzing the key operating parameters affecting the yield of the distillate product in the fractionation system, sensitivity analysis is used to determine the influence degree of the parameters on the yield of the distillate product, and the parameters with greater influence degree are adjusted preferentially.

10. The method according to claim 9, wherein the method is characterized by: The step three gradually changes the operation parameters of the fractionation system in a gradient adjustment mode, and in the parameter adjustment process, the yield and quality of the fraction product and the operation parameters of the fractionation system are monitored in real time, and the adjustment effect is recorded in time.

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