Raw oil for naphthalene distillation apparatus and production process using the same as raw material

Abstract

The application discloses raw material oil for naphthalene distillation device and a production process using the same as raw material, the raw material oil comprises dephenol naphthalene oil and naphthalene residue, the weight ratio of the dephenol naphthalene oil and the naphthalene residue is (90-105):1, the naphthalene content of the raw material oil is controlled to be 72-76%, the dephenol naphthalene oil is obtained by dephenolizing naphthalene oil collected from a side line of a distillation column of a tar distillation device, and the naphthalene residue is a by-product generated by a phthalic anhydride device; the production process using the raw material oil for naphthalene distillation device as raw material combines the naphthalene distillation device and the phthalic anhydride device, uses the raw material oil as raw material, and prepares high-quality industrial naphthalene by optimizing process parameters, so that the additional value of the naphthalene residue is improved, the raw material cost is reduced, and the comprehensive benefits are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of industrial naphthalene production technology, specifically to the feedstock oil used in naphthalene distillation equipment and the production process using it as a feedstock. Background Technology

[0002] The main production unit for industrial naphthalene is the naphthalene distillation unit. The naphthalene distillation process is a single-furnace, double-tower, pressurized continuous distillation process. The raw material is dephenolized naphthalene oil. The product wash oil is collected from the bottom of the distillation unit, and the product industrial naphthalene is collected from the top. The phthalic anhydride unit uses industrial naphthalene as raw material to produce phthalic anhydride. During the production process, naphthalene slag is generated as a byproduct, which is sold to manufacturers of water-reducing agents for blending. The naphthalene slag produced from phthalic anhydride production is sold directly for approximately 1500-2000 yuan per ton, with low added value. In contrast, the dephenolized naphthalene oil used in the naphthalene distillation unit has a comprehensive price of approximately 5500-6000 yuan per ton, resulting in higher costs. Currently, Baohua Zhanjiang's phthalic anhydride unit has an annual phthalic anhydride production of 40,000 tons, of which approximately 35 tons of naphthalene slag are produced monthly. This amount is only enough for one truckload of external sales, requiring dedicated personnel and procedures for delivery, resulting in a large workload and low economic efficiency. Therefore, the overall cost-effectiveness of selling naphthalene slag externally is low. Summary of the Invention

[0003] To address the aforementioned problems, the purpose of this invention is to provide a feedstock oil for a naphthalene distillation unit and a production process using it as a feedstock. This feedstock oil is obtained by scientifically proportioning raw naphthalene oil and naphthalene residue. Through the naphthalene distillation unit, process parameters are optimized to produce high-quality industrial naphthalene. At the same time, the industrial naphthalene is supplied to the phthalic anhydride unit as a feedstock. The two units are combined and balanced to improve overall efficiency.

[0004] Therefore, the present invention adopts the following technical solution:

[0005] This invention provides a feedstock oil for a naphthalene distillation unit, comprising dephenolized naphthalene oil and naphthalene residue, wherein the weight ratio of the dephenolized naphthalene oil to the naphthalene residue is (90-105):1, and the naphthalene content of the feedstock oil is controlled at 72-76%. The dephenolized naphthalene oil is obtained by removing phenol from naphthalene oil taken from the side stream of the distillation tower of the tar distillation unit, and the naphthalene residue is a byproduct of the phthalic anhydride unit.

[0006] Preferably, the weight ratio of the dephenolized naphthalene oil to the naphthalene residue is (95-100):1.

[0007] Preferably, the weight ratio of the dephenolized naphthalene oil to the naphthalene residue is 100:1.

[0008] Preferably, the naphthalene content of the de-powdered naphthalene oil is 68-72%.

[0009] Preferably, the naphthalene residue contains 90%-94% naphthalene.

[0010] The present invention also provides a production process for feedstock oil using a naphthalene distillation unit, comprising the following steps:

[0011] 1) Add naphthalene residue through a pipeline to the dephenolized naphthalene oil tank and mix it in proportion to prepare raw material oil;

[0012] 2) The feedstock oil is fed into the single furnace double tower of the naphthalene distillation unit. After heat exchange with the bottom oil and the top industrial naphthalene, the primary distillation tower is heated at atmospheric pressure, and then pressurized in the rectification tower. The product wash oil is collected from the bottom of the rectification tower, and the product industrial naphthalene is collected from the top of the rectification tower.

[0013] 3) The above-mentioned industrial naphthalene is fed into the phthalic anhydride unit to produce phthalic anhydride, generating naphthalene residue as a by-product. The naphthalene residue is then fed into the dephenolized oil tank through a pipeline to produce raw material oil, and the process is repeated.

[0014] Preferably, after the heat exchange temperature between the feed oil and the bottom oil of the tower is set to 90-100℃, the heat exchange temperature between the feed oil and the industrial naphthalene at the top of the tower is set to 160-170℃.

[0015] Preferably, the outlet temperature of the reboiler in the primary distillation column is set to 235-245℃.

[0016] Preferably, the heating temperature of the furnace in the distillation column is set to 312°C.

[0017] Preferably, the return flow rate is set to 8m³ / s. 3 / h.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] This invention uses a scientifically proportioned mixture of naphthalene residue and dephenolized naphthalene oil as raw material for the naphthalene distillation unit, thereby increasing the industrial value of the naphthalene residue. The industrial naphthalene produced is then used as a new raw material for the phthalic anhydride unit to produce phthalic anhydride. This not only reduces raw material costs but also combines the naphthalene distillation unit and the phthalic anhydride unit, greatly improving overall efficiency.

[0020] This invention controls the ratio of raw naphthalene oil to naphthalene residue to maintain the naphthalene content of the prepared raw oil at 72-76%, and adjusts the process parameters of the naphthalene distillation unit to precisely control the temperature and reflux flow of the distillation column, ensuring that the product quality meets 100% standards.

[0021] Currently, Baosteel Chemical Zhanjiang Co., Ltd. is the only chemical plant in China that shares both phthalic anhydride and naphthalene plants. It can directly transport materials via pipeline, which further saves transportation costs, allows for timely adjustments to the quality of raw materials and products for both plants, improves the flexibility of material allocation, reduces raw material costs, and enhances economic efficiency. Attached Figure Description

[0022] Figure 1This is a flow chart of the single-furnace, double-tower pressurized continuous distillation production process of Embodiment 1 of the present invention. Detailed Implementation

[0023] The specific implementation methods of the technical solution described herein will be further described below with reference to the accompanying drawings and specific embodiments. These embodiments are for the purpose of describing the technical solution in detail, and not for limiting the technical solution. Based on the embodiments in this description, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this description.

[0024] This application provides a feedstock oil for a naphthalene distillation unit, comprising dephenolized naphthalene oil and naphthalene residue, wherein the weight ratio of the dephenolized naphthalene oil to the naphthalene residue is (90-105):1. The dephenolized naphthalene oil is obtained by removing phenol from naphthalene oil drawn from the side stream of the distillation tower of a tar distillation unit, and the naphthalene residue is a byproduct of a phthalic anhydride unit.

[0025] Preferably, the weight ratio of the dephenolized naphthalene oil to the naphthalene residue is (95-100):1.

[0026] Preferably, the weight ratio of the dephenolized naphthalene oil to the naphthalene residue is 100:1.

[0027] Preferably, the naphthalene content of the de-powdered naphthalene oil is 68-72%.

[0028] Preferably, the naphthalene residue contains 90%-94% naphthalene.

[0029] Preferably, the naphthalene content of the raw oil is controlled at 72-76%.

[0030] This application also provides a production process for feedstock oil using a naphthalene distillation unit, comprising the following steps:

[0031] 1) Add naphthalene residue through a pipeline to the dephenolized naphthalene oil tank and mix it in proportion to prepare raw material oil;

[0032] 2) The feedstock oil is fed into the single furnace double tower of the naphthalene distillation unit. After heat exchange with the bottom oil and the top industrial naphthalene, the primary distillation tower is heated at atmospheric pressure, and then pressurized in the rectification tower. The product wash oil is collected from the bottom of the rectification tower, and the product industrial naphthalene is collected from the top of the rectification tower.

[0033] 3) The above-mentioned industrial naphthalene is fed into the phthalic anhydride unit to produce phthalic anhydride, generating naphthalene residue as a by-product. The naphthalene residue is then fed into the dephenolized oil tank through a pipeline to produce raw material oil, and the process is repeated.

[0034] Preferably, the temperature of the feed oil after heat exchange with the bottom oil of the distillation column is set to 90-100℃, and the temperature after heat exchange with the industrial naphthalene at the top of the column is set to 160-170℃. The outlet temperature of the reboiler of the primary distillation column is set to 235-245℃, the heating temperature of the furnace of the distillation column is set to 312℃, and the reflux flow rate is set to 8m³ / s. 3 / h.

[0035] Example 1

[0036] A feedstock oil for a naphthalene distillation unit comprises dephenolized naphthalene oil and naphthalene residue, wherein the weight ratio of the dephenolized naphthalene oil to the naphthalene residue is 100:1. The dephenolized naphthalene oil is obtained by removing phenol from naphthalene oil drawn from the side stream of the distillation tower of a tar distillation unit, and the naphthalene residue is a byproduct of a phthalic anhydride unit.

[0037] The naphthalene content of the above-mentioned dephenolized naphthalene oil is 72%, and the naphthalene content of the naphthalene residue is 90%.

[0038] like Figure 1 As shown in the figure, the specific steps of the production process using the feedstock oil of the naphthalene distillation unit provided in this embodiment are as follows:

[0039] 1) Add naphthalene residue to the dephenolized naphthalene oil tank through a pipeline and mix at a ratio of 100:1 to prepare raw material oil, thus obtaining raw material dephenolized naphthalene oil No. 2;

[0040] 2) The raw material, dephenolized naphthalene oil No. 2, is fed into the single-furnace double-tower naphthalene distillation unit. After exchanging heat with the bottom wash oil of the rectification tower to 95°C, it is then exchanging heat with the top industrial naphthalene of the rectification tower to 170°C before entering the primary distillation tower. The primary distillation tower is an atmospheric distillation unit, and the outlet temperature of the reboiler in the primary distillation tower is set to 245°C. The intermediate product, phenol oil, is collected from the top of the tower, and the bottom oil enters the rectification tower. The rectification tower is heated to 312°C by a heater, and the reflux flow rate is set to 8 m³ / s. 3 / h, the product collected from the bottom of the tower is wash oil, and the product collected from the top of the tower is industrial naphthalene;

[0041] 3) The above-mentioned industrial naphthalene is fed into the phthalic anhydride unit to produce phthalic anhydride, generating naphthalene residue as a by-product. The naphthalene residue is then fed into the dephenolized oil tank through a pipeline to produce raw material oil, and the process is repeated.

[0042] Comparative Example 1

[0043] The difference from Example 1 is that the weight ratio of dephenolized naphthalene oil and naphthalene residue in the raw material oil is 50:50, while all other aspects are the same.

[0044] Comparative Example 2

[0045] The difference from Example 1 is that the raw material oil is only dephenolized naphthalene oil, while everything else is the same.

[0046] Comparative Example 3

[0047] The difference from Example 1 is that in the production process using the feedstock oil for the naphthalene distillation unit, in step 2): the distillation column is heated to 305°C via a heater, and the reflux flow rate is set to 9m³ / h. 3 / h, everything else is the same.

[0048] Comparative Example 4

[0049] The difference from Example 1 is that in the production process of the feed oil used in the naphthalene distillation unit, in step 2), the outlet temperature of the reboiler of the primary distillation column is set to 230°C, and the temperature of the rectification column is heated to 305°C by a heating furnace. All other aspects are the same.

[0050] Benefit statistics:

[0051] Baosteel Chemical Zhanjiang Co., Ltd. produces 3,500 tons of dephenolized naphthalene oil and 35 tons of naphthalene residue per month, which are then blended. Based on the value of the dephenolized naphthalene oil, the price per ton increases by 4,000 yuan compared to before the improvement, resulting in a total benefit of 140,000 yuan per month. At the same time, the work related to loading and shipping and logistics processes have been optimized and eliminated, improving labor efficiency. Specific test results are shown in Table 1.

[0052] Table 1. Statistical Results of Comprehensive Benefits

[0053]

[0054] As shown in Table 1, using the raw material oil provided by this invention and using it as raw material for single-furnace double-tower pressurized continuous distillation can significantly reduce production costs, increase labor productivity, and improve economic benefits, and the product qualification rate reaches 100%.

[0055] Although embodiments of the present description 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 present description, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A feedstock oil for a naphthalene distillation apparatus, characterized in that, It is composed of a mixture of dephenolized naphthalene oil and naphthalene residue, wherein the weight ratio of the dephenolized naphthalene oil to the naphthalene residue is (90-105):1, and the naphthalene content of the mixture is controlled at 72-76%. The dephenolized naphthalene oil is obtained by dephenolizing naphthalene oil taken from the side stream of the distillation tower of the tar distillation unit. The naphthalene residue is a by-product of the phthalic anhydride unit.

2. The feedstock oil for the naphthalene distillation apparatus according to claim 1, characterized in that, The weight ratio of the dephenolized naphthalene oil to the naphthalene residue is (95-100):

1.

3. The feedstock oil for the naphthalene distillation apparatus according to claim 2, characterized in that, The weight ratio of the dephenolized naphthalene oil to the naphthalene residue is 100:

1.

4. The feedstock oil for the naphthalene distillation apparatus according to claim 1, characterized in that, The naphthalene content of the dephenolized naphthalene oil is 68-72%.

5. The feedstock oil for the naphthalene distillation apparatus according to claim 1, characterized in that, The naphthalene residue contains 90%-94% naphthalene.

6. The production process of feedstock oil using the naphthalene distillation apparatus according to any one of claims 1-5, characterized in that, Includes the following steps: 1) Add naphthalene residue to the dephenolized naphthalene oil tank through a pipeline and prepare it into feedstock oil according to the specified ratio; 2) Send the feedstock oil into the single furnace double tower of the naphthalene distillation unit, exchange heat with the bottom oil and the top industrial naphthalene, heat the primary distillation tower at atmospheric pressure, and then pressurize it in the rectification tower. The product wash oil is collected from the bottom of the rectification tower and the product industrial naphthalene is collected from the top of the rectification tower; 3) Use the above-mentioned industrial naphthalene as raw material to produce phthalic anhydride in the phthalic anhydride unit, generating by-product naphthalene residue. The naphthalene residue is then fed into the dephenolized oil tank through a pipeline to prepare feedstock oil, and the cycle is repeated.

7. The production process of feedstock oil using a naphthalene distillation unit according to claim 6, characterized in that, After the heat exchange temperature between the feed oil and the bottom oil of the tower is set to 90-100℃, the heat exchange temperature between the feed oil and the industrial naphthalene at the top of the tower is set to 160-170℃.

8. The production process of feedstock oil using a naphthalene distillation unit according to claim 6, characterized in that, The outlet temperature of the reboiler in the primary distillation column is set to 235-245℃.

9. The production process of feedstock oil using a naphthalene distillation unit according to claim 6, characterized in that, The heating temperature of the furnace in the distillation column is set to 312℃.

10. The production process of feedstock oil using a naphthalene distillation unit according to claim 6, characterized in that, The reflux rate of the distillation column is set to 8 m³ / h.

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