Process optimization method for improving conversion rate of dodecanol in sodium flotation reagent and reducing COD (Chemical Oxygen Demand) of wastewater

Abstract

The invention relates to the technical field of sodium flotation reagents, and discloses a process optimization method for improving the conversion rate of dodecanol in a sodium flotation reagent and reducing the COD (Chemical Oxygen Demand) of wastewater, which comprises the following steps: preparing three reaction kettles, transforming a No.3 reaction kettle, namely transforming a gas phase system of the reaction kettle, additionally installing a temperature monitoring device, and carrying out a pressure resistance experiment. A segmented control strategy is adopted: the dripping speed of morpholine and the reaction temperature of a No.3 reaction kettle are regulated and controlled, the stirring speed, the catalyst dosage and the hydrogen flow are regulated and controlled, a condensate discharge control experiment is carried out, finally, a rectification system experiment is carried out, and parameters of a dehydration tower rectification system are monitored. According to the present invention, the condenser, the gas phase pipe, the thermometer, the sight glass and the like of the reaction kettle are transformed so as to ensure the safe and stable experiment, provide the good foundation for the process optimization, and significantly improve the conversion rate and the grade of the product by adjusting the morpholine dropping speed and time, the stirring speed, the reaction kettle temperature, the catalyst consumption and other parameters.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sodium flotation reagent, in particular to a process optimization method for improving the conversion rate of dodecanol in sodium flotation reagent and reducing the COD of wastewater. BACKGROUND

[0002] The production of sodium flotation reagent of Jingcheng Chemical Company includes two major processes of reaction synthesis and rectification recovery. The raw material dodecanol is pumped into the synthesis reaction kettle, the catalyst is added, the nitrogen is replaced, the hydrogen is passed to activate the temperature, and then the morpholine is passed according to the flow to synthesize dodecyl morpholine. The water, morpholine and dodecyl alcohol generated in the gas phase in the reaction are dehydrated by the dehydration tower, separated and recovered by the separation tower, and then recycled.

[0003] Although the product can meet the demand of potassium fertilizer company, there are still some problems: First, the conversion rate of the product is low, and the production capacity does not reach the design value. Second, the separation liquid in the synthesis process is large, which leads to the increase of the load of the rectification system, the exceeding of the organic matter in the wastewater, the increase of the unit consumption of public engineering such as nitrogen, electricity and steam, and the high cost of disposing the high COD wastewater by the third party. Therefore, a process optimization method for improving the conversion rate of dodecanol in sodium flotation reagent and reducing the COD of wastewater is proposed to solve the above problems. SUMMARY

[0004] (I) Technical problems to be solved In view of the shortcomings of the prior art, the present application provides a process optimization method for improving the conversion rate of dodecanol in sodium flotation reagent and reducing the COD of wastewater, which aims to improve the synthesis conversion rate through technical optimization, solve the problems of heavy load of rectification system, long treatment time and incomplete treatment, reduce the energy consumption of public engineering and the cost of wastewater disposal, make the wastewater discharge meet the environmental protection requirements, and finally realize the energy saving, cost reduction and efficiency increase of sodium flotation reagent production, and provide technical support for sustainable production of enterprises.

[0005] (II) Technical solutions In order to achieve the above purpose of improving the synthesis conversion rate, the present application provides the following technical solutions: a process optimization method for improving the conversion rate of dodecanol in sodium flotation reagent and reducing the COD of wastewater, comprising the following steps: Step 1: prepare three reaction kettles, which are marked as No. 1 reaction kettle, No. 2 reaction kettle and No. 3 reaction kettle in turn, and modify the No. 3 reaction kettle, wherein the gas phase system of the reaction kettle is modified: a first condenser and a second condenser are installed at the top of the No. 3 reaction kettle, the pipe diameter of the gas phase is expanded from DN100 to DN150, and the pipe height is increased from 1 meter to 1.6 meters; Step 2: temperature monitoring device is installed: a temperature gauge with a range of 0-300℃ is installed at the head of the gas phase pipe of the No. 3 reaction kettle, which is convenient for observing the influence of process parameters on the temperature of the gas phase pipe and the separation liquid; Step 3: Pressure test: 3MPa pressure test on the installed first and second condensers and their pipeline equipment, the test duration is more than 2 hours, the system pressure drop is required to be less than 0.05MPa / hour, after the test is qualified, check the modified equipment and pipelines to exclude safety hazards before the experiment can be carried out; Step 4: Adopting a segmented control strategy: controlling the dropping speed of morpholine and the reaction temperature of the No. 3 reactor, and adjusting the stirring speed, catalyst dosage and hydrogen flow rate; Step 5: Conducting a condensate discharge control experiment to control the discharge speed of the first-stage condensate of the No. 3 reactor into the condensate tank; Step 6: Conducting a rectification system experiment to monitor the parameters of the dehydration tower rectification system, including time, tower top temperature, tower bottom temperature, feed rate, reflux rate, tower top output, reflux ratio, tower load, wastewater COD and wastewater color.

[0006] Preferably, the temperature gradient control is achieved by the following way: constant 210℃ for the first 2 hours, linear temperature rise to 220℃ for the last 2 hours, and real-time adjustment of heating power through gas phase pipe temperature feedback.

[0007] Preferably, the segmented flow control needs to meet the following requirements: the dropping speed of morpholine is adjusted at 80kg / h for 0-30 minutes, 120kg / h for 31-60 minutes, 160kg / h for 61-180 minutes, and 185kg / h for 181-240 minutes.

[0008] Preferably, the catalyst intensification includes: using bagged solid catalyst, the dosage is 200% of the conventional process, and the catalyst is added synchronously with the raw materials after nitrogen replacement.

[0009] Preferably, the stirring intensity optimization needs to ensure that the stirring speed is stabilized at 40±1HZ, and the contrast experiment conditions of 30HZ and 40HZ are formed with the No. 1-2 reactors.

[0010] Preferably, the hydrogen flow rate control includes: maintaining a constant flow rate of 2NM³ / H during the reaction stage, and adjusting to 1.5NM³ / H during the temperature rising and activation stage.

[0011] Preferably, the raw material ratio adjustment control of the No. 3 reactor adjusts the dodecanol dosage to 1250kg and the morpholine dosage to 610kg, and the mass ratio of dodecanol to morpholine in the raw material ratio is 1250:610≈2.05:1, and the actual added dodecanol to recovered dodecanol ratio needs to be ≥4:1.

[0012] Preferably, the rectification system operating parameters need to meet the following requirements: feed rate 0.17-0.8m³ / h, reflux rate 0.1-0.3m³ / h, and tower load control within the range of 38-60%.

[0013] Preferably, the condensate discharge control includes: observing the gas phase state through a glass sight glass, dynamically adjusting the discharge rate according to the pressure change in the vessel, and ensuring a stable temperature gradient throughout the condenser.

[0014] (III) Beneficial Effects Compared with existing technologies, this invention provides a process optimization method for improving the conversion rate of dodecanol in sodium flotation reagents and reducing COD in wastewater, which has the following beneficial effects: This process optimization method for improving the conversion rate of dodecyl alcohol in sodium flotation reagents and reducing the COD of wastewater, through modifications to the condenser, gas phase pipe, thermometer, and sight glass of the reactor, ensured the safe and stable conduct of the experiment, providing a good foundation for process optimization. By adjusting parameters such as morpholine dropping rate and time, stirring speed, reactor temperature, and catalyst dosage, the product conversion rate and grade were significantly improved. Among them, the comprehensive adjustment of multiple parameters and doubling of catalyst had a significant effect on improving product grade. Specifically, the single-pass conversion rate of dodecyl alcohol increased from 67.78% to over 82%, the single-batch processing capacity of the distillation system increased by 60%, the COD content of wastewater decreased to below 800 ppm, the grade of dodecylmorpholine product increased to 95%, the total amount of separated liquid decreased by 15-23%, and the load of the distillation column decreased by over 36%. Attached Figure Description

[0015] Figure 1 This is a process flow diagram illustrating the conversion rate of dodecanol and the reduction of COD in wastewater using the sodium flotation reagent of this invention. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please see Figure 1 A process optimization method for improving the conversion rate of dodecanol in sodium flotation reagents and reducing COD in wastewater includes the following steps: Step 1: Prepare three reactors, numbered No. 1, No. 2 and No. 3 respectively, and modify No. 3. The modification of the gas phase system of the reactor is as follows: add a primary condenser and a secondary condenser to the top of No. 3, expand the diameter of the gas phase pipe from DN100 to DN150, and increase the pipe height from 1 meter to 1.6 meters. Step 2: Temperature monitoring device installation: Install a thermometer with a range of 0-300℃ at the head of the gas phase tube of reactor No. 3 to facilitate observation of the influence of process parameters on the gas phase tube temperature and the separated liquid. Step 3: Pressure withstand test: Conduct a 3MPa pressure withstand test on the added primary and secondary condensers and their pipeline equipment. The test duration shall exceed 2 hours. The system pressure drop shall be less than 0.05MPa / hour. After the test is passed, inspect all modified equipment and pipelines and eliminate any safety hazards before the test can be carried out. Step 4: Adopt a segmented control strategy: Adjust the dropping rate of morpholine and the reaction temperature of reactor No. 3, and regulate the stirring speed, catalyst dosage and hydrogen flow rate; Step 5: Conduct a condensate discharge control experiment to control the discharge rate of the first stage of condensate phase from reactor No. 3 into the condensate tank; Step 6: Conduct distillation system experiments and monitor the parameters of the dehydration tower distillation system, including time, top temperature, bottom temperature, feed rate, reflux rate, top output, reflux ratio, tower load, wastewater COD, wastewater color, and other indicators.

[0018] The following is the actual experiment of this scheme. I. Experimental Basis 1.1 Current Status of Original Process Production In the process design, the target single-pass conversion rate of dodecyl alcohol was 94%, and the yield of dodecylmorpholine was 89.9%. However, in actual industrial production, monitoring of the water volume in the distillation system and the recovery of dodecyl alcohol and morpholine revealed that the design targets were not met. Data from 12 consecutive batches of production (data sourced from the main control log and shift handover logs) showed that the total dodecyl alcohol consumption was 50,661.2 kg, with an average consumption of 4,221.77 kg per batch; the total newly added dodecyl alcohol weight was 34,340 kg, with an average newly added weight of 2,861.67 kg per batch; and the total weight recovered in the distillation tank was 16,321.2 kg, with an average recovery weight of 1,360.1 kg per batch. Based on the formula for calculating the single-pass conversion rate of dodecyl alcohol (single-pass conversion rate = newly added dodecyl alcohol / (newly added dodecyl alcohol + total recovered material) × 100%), the actual single-pass conversion rate was calculated to be 67.78%. Each batch contained 1360.1 kg of unconverted dodecanol, far exceeding the designed unconverted amount of 210.4 kg. These unconverted substances form gas-liquid mixtures with other components and enter subsequent processes, which is the main reason for the low conversion rate, high distillation load, and high energy consumption.

[0019] 1.2 Experimental Objectives Technical specifications include a single-pass conversion rate of 75% for dodecyl alcohol, a yield of more than 75% for dodecylmorpholine, a single-batch distillation system capacity of more than 1000 kg, and a COD content in wastewater of less than 1000 ppm.

[0020] The overall goal is to achieve stable operation of the distillation system through process optimization, reduce energy consumption and costs, and ensure that wastewater discharge meets environmental protection requirements.

[0021] II. Experimental Setup and Modification 2.1 Selection of Experimental Apparatus Reactor No. 3 was selected as the experimental device to avoid affecting the original production process and pipelines.

[0022] 2.2 Equipment Modification Content Condenser and vapor phase pipe modification: To reduce the carryover of liquid dodecanol by the vapor phase, a brand-new primary and secondary condenser was installed in reactor No. 3. The diameter of the vapor phase pipe was changed from DN100 to DN150, and the height of the vapor phase pipe was increased from 1 meter to 1.6 meters. Temperature monitoring device installation: A thermometer with a range of 0-300℃ was installed at the head of the vapor phase pipe in reactor No. 3 to facilitate observation of the impact of process parameters on the vapor phase pipe temperature and the separated liquid. Visual monitoring device installation: A sight glass was installed between the primary and secondary condensers to observe the impact of changes in process parameters on the production process. Pressure withstand test: A 3MPa pressure withstand test was conducted on the newly installed primary and secondary condensers and their pipeline equipment. The test duration exceeded 2 hours, and the system pressure drop was required to be less than 0.05MPa / hour. After passing the test, all modified equipment and pipelines were inspected, and any safety hazards were eliminated before further testing could proceed.

[0023] III. Experimental Content, Phenomena, and Conclusions 3.1 Equipment Safety Verification Experiment After inspecting all equipment and pipelines in Reactor No. 3 following the process modification, potential safety hazards were eliminated, and a batch of products was subsequently produced. Experimental observations: During production, data such as reactor temperature, reactor pressure, separated liquid temperature, total separated liquid volume, product quality, and product yield were consistent with those of Reactors No. 1 and No. 2. Experimental conclusions: All production data of the modified Reactor No. 3 are normal and meet the requirements for safe production.

[0024] 3.2 Experiment on process consistency and temperature change observation The experiment aimed to ensure consistent production processes across reactors 1-3. Two key aspects were observed: first, the relationship between the temperature at the head of the vapor phase tube in reactor 3 and the morpholine dropping time; second, the normality of the operating temperatures of the newly installed primary and secondary condensers. This was repeated three times, and data were recorded. Experimental observations showed that key data such as temperature and pressure in reactor 3 were consistent with those in reactors 1 and 2. The temperature at the head of the vapor phase tube in reactor 3 decreased from 205℃ to 130℃ from the start to the end of morpholine dropping. The amount of separated liquid was higher in the first two hours after morpholine dropping, and significantly decreased in the following two hours. The experimental conclusions were that all production data for reactor 3 were normal; the reaction was vigorous in the early stages of morpholine dropping, resulting in a high temperature at the head of the vapor phase tube and a large amount of separated liquid; the temperature at the head of the vapor phase tube gradually decreased throughout the entire morpholine dropping process.

[0025] 3.3 Experiment on Adjusting the Dropping Acceleration of Morpholine 3.3.1 Initial deceleration and subsequent acceleration experiment The initial dropping rate of morpholine in reactor No. 3 was reduced, while the subsequent dropping rate was increased. The temperature of the gas phase tube was controlled to not exceed 160℃, and other processes were kept consistent with those in reactors No. 1 and No. 2. The effect on the volume of the separated liquid and product quality was observed, and this was repeated for three batches. After the morpholine dropping was completed, the volume of the separated liquid decreased slightly. The experimental conclusion is that this dropping rate adjustment method has a relatively small impact on the volume of the separated liquid.

[0026] 3.3.2 Experiment with reduced speed and extended total dropping time The initial dropping rate of morpholine in reactor No. 3 was reduced, and the total dropping time was extended, while other processes remained the same as in reactors No. 1 and No. 2. The effects on the amount of separated liquid and product quality were observed, and this was repeated for three batches. Experimental findings: The amount of separated liquid was significantly reduced in the initial dropping phase. After the morpholine addition was completed, the separated liquid in reactor No. 3 was essentially the same as that in reactors No. 1 and No. 2, and the product quality improved from 89.6% to 93.2%. Experimental conclusion: Reducing the initial dropping rate and extending the reaction time can improve product quality.

[0027] 3.4 Experiment on Adjusting Stirring Speed The stirring speed of reactor No. 3 was increased to 40 Hz, while reactors No. 1 and No. 2 were kept at 30 Hz, with other processes remaining the same. The effects on the quality of the separated liquid and the product were observed, and the experiment was repeated for three batches. Experimental results: Product quality in reactor No. 1 was 90.03%, in reactor No. 2 it was 90.39%, and in reactor No. 3 it was 92.9%. Other production data were basically consistent. Increasing the stirring speed of reactor No. 3 to 40 Hz improved product quality.

[0028] 3.5 Reactor Temperature Adjustment Experiment 3.5.1 Experiment with the reactor temperature reduced to 215℃ The temperature of reactor No. 3 was lowered to 215℃, while reactors No. 1 and No. 2 were kept at 220℃. Other processes remained the same. The effect on the amount of separated liquid and product quality was observed, and this was repeated for three batches. Experimental phenomena: In the first batch, during the dropwise addition, the amount of separated liquid in reactor No. 3 was 0% less than that in reactor No. 1 and 8% less than that in reactor No. 2, with a total separated liquid content of 160%. The product mass of No. 1 was 92.6%, No. 2 was 90.3%, and No. 3 was 92.6%. In the second batch, the amount of separated liquid in reactor No. 3 was 15% less than that in reactor No. 2, with a total separated liquid content of 160%. Reactor No. 1 underwent maintenance, and the mass of No. 2 and No. 3 was 93%. In the third batch, the amount of separated liquid in reactor No. 3 was 3% less than that in reactor No. 1 and 12% less than that in reactor No. 2, with a total separated liquid content of 160%. The mass of No. 1 was 91%, No. 2 was 93%, and No. 3 was 93%. Experimental conclusion: Lowering the reactor temperature to 215℃ resulted in a slight decrease in the amount of separated liquid.

[0029] 3.5.2 Experiment with the reactor temperature reduced to 210℃ The temperature of reactor No. 3 was lowered to 210℃, while reactors No. 1 and No. 2 were kept at 220℃, with other processes remaining the same. The effect on the amount of separated liquid and product quality was observed, and the experiment was repeated for three batches. During the dropwise addition, the amount of separated liquid in reactor No. 3 was 18% less than that in reactor No. 1 and 23% less than that in reactor No. 2, with a total separated liquid content of 160%. The product quality of reactors No. 1 and No. 2 was 92%, while that of reactor No. 3 decreased to 86%. Experimental conclusion: Lowering the reactor temperature to 210℃ significantly reduced the amount of separated liquid, but also significantly reduced the product quality.

[0030] 3.6 Hydrogen Flow Control Experiment The hydrogen flow rate during the reaction stage of reactor No. 3 was controlled at 1.5 standard cubic meters per hour, with other parameters consistent with those of reactors No. 1 and No. 2. Production data remained largely consistent. At this hydrogen flow rate, production was stable with no significant impact.

[0031] 3.7 Staged Temperature Control Experiment The temperature of reactor No. 3 was controlled at 210℃ for the first 2 hours after morpholine addition and 220℃ for the next 2 hours, with other parameters consistent with those of reactors No. 1 and No. 2. No relevant phenomena were recorded. No relevant conclusions were drawn.

[0032] 3.8 Multi-parameter integrated adjustment experiment The parameters of reactor No. 3 were adjusted as follows: dodecanol 1250 kg, reactor temperature 215℃, morpholine 610 kg, hydrogen flow rate 2 NM³ / H. The morpholine dropping rate was controlled in stages (0-30 minutes 80 kg / h; 31-60 minutes 120 kg / h; 61-180 minutes 160 kg / h; 181-240 minutes 185 kg / h). Changes in the volume of separated liquid and product quality were observed. An increase in condensate in reactor No. 3 significantly improved the product grade: condensate in reactor No. 1 was 148.77% with a product grade of 91%; condensate in reactor No. 2 was 148.48% with a product grade of 91%; and condensate in reactor No. 3 was 169.21% with a product grade of 95%. Changing the morpholine dropping rate and time increased the condensate volume and significantly improved the product grade; other data remained consistent.

[0033] 3.9 Catalyst Dosage Adjustment Experiment Double the amount of catalyst (2 bags) in reactor No. 3, while keeping other parameters the same as No. 1 and No. 2. The condensate volume remains basically the same, but the product quality improves: No. 1 94%, No. 2 92%, and No. 3 95%. Doubling the catalyst amount improves the product quality but has no significant impact on the condensate volume.

[0034] 3.10 Condensate Discharge Control Experiment Control the discharge rate of the first-stage condensate phase from reactor No. 3 into the condensate tank, monitor the reactor pressure and the temperature throughout the condenser, observe the gas phase through the sight glass, and ensure safety throughout the process. No relevant phenomena were recorded. No relevant conclusions were drawn.

[0035] IV. Experimental Data of the Distillation System 4.1 Data Collection Status The parameters of the dehydration tower distillation system were monitored, and data were collected from September 20 to October 5, 2025, covering indicators such as time, top temperature, bottom temperature, feed rate, reflux rate, top product, reflux ratio, tower load, wastewater COD, and wastewater color. Specific data are shown in the table below: 4.2 Data Trend Analysis The data shows that the top temperature fluctuated between 81.42 and 92.42℃, and the bottom temperature varied between 108.15 and 135.85℃. The feed rate, reflux rate, top product rate, and reflux ratio all fluctuated to some extent. The column load showed an overall downward trend, decreasing from 60.48 to 38.45, indicating that the processing efficiency of the distillation system has changed, which may be related to process optimization and adjustments.

[0036] V. Completion Status of Planned Tasks 5.1 Indicator Comparison The various indicators achieved in the experiment were compared with those stipulated in the contract, as shown in the table below: 5.2 Completion Status Analysis All technical indicators were exceeded. The single-pass conversion rate of dodecyl alcohol increased by more than 7% compared to the agreed value, the yield of dodecylmorpholine increased by 5%, the single-batch distillation capacity was 1.6 times the agreed value, and the wastewater COD was 200 ppm lower than the agreed value. This fully demonstrates that the process optimization experiment has achieved remarkable results and realized the goals of improving conversion rate, reducing energy consumption, and improving environmental protection indicators.

[0037] In summary, the process optimization method for improving the conversion rate of dodecanol in sodium flotation reagents and reducing wastewater COD involved modifications to the condenser, vapor phase pipe, thermometer, and sight glass of reactor No. 3. This ensured the safe and stable conduct of the experiment and provided a solid foundation for process optimization. By adjusting parameters such as morpholine dropping rate and time, stirring speed, reactor temperature, and catalyst dosage, the product conversion rate and grade were significantly improved. The comprehensive adjustment of multiple parameters and doubling the catalyst dosage had a particularly significant effect on improving product grade. The single-batch distillation throughput increased substantially, while the column load decreased, indicating improved operating efficiency and reduced energy consumption in the distillation system. The wastewater COD was reduced to 800 ppm, meeting environmental protection requirements and reducing wastewater treatment costs.

[0038] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0039] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A process optimization method for improving the conversion of dodecanol in sodium flotation reagents and reducing the COD of wastewater, characterized by: Comprising the following steps: Step 1: Prepare three reactors, labeled No. 1 reactor, No. 2 reactor and No. 3 reactor in turn, and modify No. 3 reactor, wherein the gas phase system of the reactor is modified: a first condenser and a second condenser are installed at the top of No. 3 reactor, the gas phase pipe diameter is expanded from DN100 to DN150, and the pipe height is increased from 1 meter to 1.6 meters; Step 2: Temperature monitoring device installation: a temperature gauge with a range of 0-300℃ is installed at the head of the gas phase pipe of No. 3 reactor to facilitate observation of the influence of process parameters on the temperature of the gas phase pipe and the separated liquid; Step 3: Pressure resistance experiment: conduct a 3MPa pressure resistance experiment on the installed first and second condensers and their pipeline equipment, the experiment lasts more than 2 hours, and the system pressure drop is required to be less than 0.05MPa / hour, after the experiment is qualified, check the modified equipment and pipelines, and exclude safety hazards before the experiment can be carried out; Step 4: Adopt a segmented control strategy: control the dropping speed of morpholine and the reaction temperature of No. 3 reactor, and control the stirring speed, catalyst dosage and hydrogen flow; Step 5: Conduct a condensate discharge control experiment to control the discharge speed of the first condensate phase of No. 3 reactor into the condensate tank; Step 6: Conduct a rectification system experiment to monitor the parameters of the dehydration tower rectification system, including time, tower top temperature, tower bottom temperature, feed rate, reflux rate, tower top yield, reflux ratio, tower load, wastewater COD and wastewater color.

2. The process optimization method for improving the conversion rate of dodecanol in sodium flotation reagents and reducing the COD of wastewater according to claim 1, characterized in that: The temperature gradient control is achieved by the following way: constant 210℃ for 2 hours before morpholine dropping, linear temperature rise to 220℃ for 2 hours, and real-time adjustment of heating power through gas phase pipe temperature feedback.

3. The process optimization method for improving the conversion rate of dodecanol in sodium flotation reagents and reducing the COD of wastewater according to claim 1, characterized in that: The segmented flow control needs to meet: the dropping speed of morpholine is adjusted at 80kg / h for 0-30 minutes, 120kg / h for 31-60 minutes, 160kg / h for 61-180 minutes, and 185kg / h for 181-240 minutes.

4. The process optimization method for improving the conversion rate of dodecanol in sodium flotation reagents and reducing the COD of wastewater according to claim 1, characterized in that: The catalyst intensification includes: using bagged solid catalyst, the dosage is 200% of the conventional process, and the catalyst is added synchronously with the raw material after nitrogen replacement.

5. The process optimization method for improving the conversion of dodecanol in a sodium flotation reagent and reducing the COD of wastewater according to claim 1, characterized in that: The stirring intensity optimization needs to ensure: the stirring speed is stable at 40±1HZ, and the comparison experiment conditions of 30HZ and 40HZ are formed with No. 1-2 reactors.

6. The process optimization method for improving the conversion of dodecanol in a sodium flotation reagent and reducing the COD of wastewater according to claim 1, characterized in that: The hydrogen flow control includes: maintaining a constant flow of 2NM³ / H during the reaction stage, and adjusting to 1.5NM³ / H during the temperature rising and activation stage.

7. The process optimization method for improving the conversion of dodecanol in sodium flotation reagents and reducing the COD of wastewater according to claim 1, characterized by: The raw material ratio adjustment control of No. 3 reactor includes: the dosage of dodecanol is 1250kg, and the dosage of morpholine is 610kg, the mass ratio of dodecanol to morpholine in the raw material ratio is 1250:610≈2.05:1, and the actual added dodecanol to recovered dodecanol ratio needs to be ≥4:

1.

8. The process optimization method for improving the conversion of dodecanol in sodium flotation reagents and reducing the COD of wastewater according to claim 1, characterized by: The rectification system operating parameters need to meet: the feed rate is 0.17-0.8m³ / h, the reflux rate is 0.1-0.3m³ / h, and the tower load is controlled within the range of 38-60%.

9. The process optimization method for improving the conversion of dodecanol in a sodium flotation reagent and reducing the COD of wastewater according to claim 1, characterized in that: The condensate discharge control includes: observing the gas phase state through the glass sight glass, dynamically adjusting the discharge speed according to the change of the kettle pressure, and ensuring the stability of the temperature gradient of the whole condenser.

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