CN114437754B - Method for producing low-sulfur marine residue fuel oil by using low-sulfur paraffin-based crude oil - Google Patents

Abstract

The invention provides a method for producing low-sulfur marine residual fuel oil by using low-sulfur paraffin-based crude oil, which includes: mixing low-sulfur paraffin-based crude oil with secondary processed inferior heavy oil and then performing atmospheric distillation to obtain naphtha and straight-run oil respectively. Diesel oil, light wax oil and normal pressure residual oil; after the normal pressure residual oil is separated by vacuum flash evaporation, heavy wax oil and deep-drawn normal pressure residual oil are obtained; and the deep-drawn normal pressure residual oil and straight-run diesel oil are mixed to obtain Low sulfur marine residual fuel oil. The low-sulfur marine residual fuel oil obtained by this method has the advantages of high yield, low pour point, and low paraffin content. It can effectively solve the problem that low-sulfur paraffin-based crude oil cannot be used to produce low-sulfur standard-compliant crude oil because it is rich in paraffin and has a high freezing point. The problem of marine residual fuel oil has low production cost and good application prospects.

Description

Method for producing low-sulfur marine residual fuel oil using low-sulfur paraffin-based crude oil

Technical field

The invention relates to the technical field of petrochemical industry, and specifically relates to a method for producing low-sulfur marine residual fuel oil using low-sulfur paraffin-based crude oil.

Background technique

On and after January 1, 2020, according to the provisions of the MAPPOL Convention, the sulfur content of marine fuel used by ships should not exceed 0.5%. At the same time, the Marine Fuel Oil Standard of the People's Republic of China GB17411-2015 stipulates various index requirements for low-sulfur marine residual fuel oil. Among them, the index of RMG180 requires that the sulfur content should not exceed 0.5%, the pour point should not exceed 30°C, and the ash content (mass fraction) Not more than 0.1%, vanadium content not more than 350mg/kg, kinematic viscosity not more than 180mm ² /s.

Crude oil is classified according to sulfur content and can be divided into four categories: ultra-low sulfur crude oil, low sulfur crude oil, sulfur crude oil and high sulfur crude oil. Ultra-low sulfur crude oil and some low-sulfur crude oil can theoretically be used to produce fuel oil with a sulfur content of less than 0.5% without desulfurization process, but they also need to meet other indicators stipulated in the current marine fuel oil standards.

The hydrocarbon components in crude oil are mainly divided into alkanes, cycloalkanes, and aromatic hydrocarbons. According to the different hydrocarbon components, it can be divided into three categories: paraffin-based petroleum, naphthenic-based petroleum and intermediate-based petroleum. Paraffin-based petroleum contains more alkanes; naphthenic-based petroleum contains more naphthenes and aromatic hydrocarbons; intermediate-based petroleum is somewhere in between. Currently, most of the crude oil that has been mined in China is based on low-sulfur paraffin, and crude oil from Daqing and other places falls into this category. Among them, the most representative Daqing crude oil has low sulfur content, high wax content and high pouring point. It can produce high-quality kerosene, diesel, solvent oil, lubricating oil and commercial paraffin, but it cannot produce low-quality crude oil that meets the marine fuel oil standards. Sulfur marine residual fuel oil is mainly due to the high wax content and high freezing point of low-sulfur paraffin-based crude oil. Therefore, it is often used in conventional atmospheric distillation towers (normal pressure towers in refineries) and vacuum distillation towers (in refineries). The normal pressure residue and vacuum residue cut out from the vacuum tower also have high freezing points and cannot be used in large quantities as low-sulfur marine residue fuel oil. If a process can be developed to directly produce low-sulfur marine residual fuel oil from low-sulfur paraffin-based crude oil through one-time processing, it will greatly increase the capacity of my country's refineries to produce marine residual fuel oil. Currently, there are very few refineries that can produce low-sulfur marine residual fuel oil that meets the latest standards. There is a large gap in the low-sulfur fuel oil market, and companies are extremely urgent for low-sulfur fuel oil production technology.

Patent application CN110872533A discloses a low-sulfur heavy marine fuel oil and its preparation method: including the following raw materials in parts by weight: 40 to 65 parts of residual oil, 5 to 15 parts of catalytic slurry, and 5 to 20 parts of styrene tar. , 5 to 20 parts of ethylene tar, 5 to 20 parts of diesel, 0.2 to 1 part of additive OP-10, 0.1 to 0.5 part of additive AES, stir and mix according to the corresponding preparation steps to obtain low-sulfur heavy marine fuel oil. The residual oil described therein is hydrogenated residual oil, which is a secondary processing product of normal pressure residual oil and vacuum residual oil, and the production cost is high.

Patent application CN110982561A discloses a residual ship fuel oil and its production method, which is prepared from raw materials including the following components: 35 to 60 parts by weight of vacuum residual oil; 25 to 32 parts by weight of medium-temperature coal tar. ; Coal and diesel oil 5 to 15 parts by weight; refined wax oil 10 to 25 parts by weight; lubricating oil regeneration oil 2 to 10 parts by weight. It contains a large amount of secondary processing oil, such as refined wax oil. The production cost is high and there are many blending components.

The published literature currently focuses on using residual oil or hydrogenated residual oil to directly blend with a large amount of secondary processing oil to produce marine residual fuel oil. Either the production cost is high or there are many blending components, and it is impossible to solve the problem of how to use low-sulfur fuel oil. Problems in producing marine residual fuel oil from paraffin-based crude oil.

It should be noted that the information disclosed in the foregoing background section is only for enhancement of background understanding of the invention and therefore it may contain information that does not constitute the prior art that is already known to a person of ordinary skill in the art.

Contents of the invention

A main purpose of the present invention is to overcome at least one defect of the above-mentioned prior art and provide a method for producing low-sulfur marine residual fuel oil using low-sulfur paraffin-based crude oil, so as to solve the problem of low-sulfur paraffin-based crude oil having a high freezing point. Issues for producing compliant low sulfur marine residual fuel oil.

In order to achieve the above objects, the present invention adopts the following technical solutions:

The invention provides a method for producing low-sulfur marine residual fuel oil using low-sulfur paraffin-based crude oil, which includes: mixing low-sulfur paraffin-based crude oil with secondary processed inferior heavy oil and then performing atmospheric distillation to obtain naphtha and straight-run oil respectively. Diesel oil, light wax oil and normal pressure residual oil; after the normal pressure residual oil is separated by vacuum flash evaporation, heavy wax oil and deep-drawn normal pressure residual oil are obtained; and the deep-drawn normal pressure residual oil and straight-run diesel oil are mixed to obtain Low sulfur marine residual fuel oil.

According to one embodiment of the present invention, atmospheric distillation is performed in an atmospheric distillation tower, and the atmospheric furnace outlet temperature of the atmospheric distillation tower is 370°C to 390°C.

According to an embodiment of the present invention, the pressure of reduced pressure flash evaporation is 7 kpa to 20 kpa.

According to one embodiment of the present invention, the aromatic content of the secondary processed inferior heavy oil is 37wt%-75wt%, the sulfur content is less than 0.5wt%, and the distillation range is 330°C-480°C.

According to one embodiment of the present invention, the secondary processed inferior heavy oil is selected from one of catalytic cracking diesel, coked diesel, catalytic cracking recycled oil, desolidified catalytic cracking oil slurry, hydrogenated catalytic cracking diesel and coal tar, or Various.

According to one embodiment of the present invention, the sum of the colloid and asphaltene contents in the low-sulfur paraffin-based crude oil is less than 10wt%, the wax content of the low-sulfur paraffin-based crude oil is 25wt% to 35wt%, and the sulfur content is less than 0.35wt%. , the freezing point is 30℃~36℃, and the pour point is 33℃~40℃.

According to one embodiment of the present invention, the mass ratio of low-sulfur paraffin-based crude oil to secondary processed inferior heavy oil is 95:5 to 85:15.

According to one embodiment of the present invention, the mass ratio of deep-drawn atmospheric pressure residual oil and straight-run diesel oil is 90:10 to 70:30.

According to an embodiment of the present invention, the distillation range of naphtha is 30-250°C, the distillation range of straight-run diesel is 200-350°C, the distillation range of light wax oil is 330-390°C, and the distillation range of atmospheric residual oil is The distillation point temperature of 5% volume is not less than 370℃.

According to one embodiment of the present invention, the distillation range of the heavy wax oil is 370-460°C, and the distillation range of the deep-drawn atmospheric pressure residual oil is 5% volume. The distillation point temperature is not less than 390°C.

According to an embodiment of the present invention, the sulfur content of the low-sulfur marine residual fuel oil is less than 0.5wt%, and the pour point is less than 30°C.

According to one embodiment of the present invention, after the deep-drawn atmospheric pressure residual oil is mixed with straight-run diesel oil, other marine residual fuel oils are added and mixed to obtain low-sulfur marine residual fuel oil; wherein the other marine residual fuel oils are selected from hydrogenation One or more of heavy oil, hydrogenated diesel, catalytically cracked diesel, coked diesel, catalytically cracked recycled oil, desolidified catalytic cracked oil slurry, hydrogenated catalytically cracked diesel and coal tar.

It can be seen from the above technical solutions that the beneficial effects of the present invention are:

The present invention proposes a method for producing low-sulfur marine residual fuel oil by using low-sulfur paraffin-based crude oil. This method can reduce atmospheric distillation and vacuum flash evaporation by introducing secondary processing of inferior heavy oil and mixing it with low-sulfur paraffin-based crude oil. The residual amount of wax in the atmospheric pressure residue and deep-drawn atmospheric pressure residue obtained after separation is reduced to reduce the overlap of wax oil and obtain deep-drawn atmospheric pressure residue with lower wax content and pour point. At the same time, part of the straight-run diesel obtained after the distillation of low-sulfur paraffin-based crude oil is mixed with the deep-drawn atmospheric residual oil. The resulting low-sulfur marine residual fuel oil has the advantages of high yield, low pour point, and low paraffin content, and solves the problem. Low-sulfur paraffin-based crude oil cannot be used to produce low-sulfur marine residual fuel oil that meets the RMG180 index specified in GB17411-2015 because it is rich in paraffin and has a high freezing point. The investment cost is low and other secondary processing costs are reduced. It has Good application prospects.

Description of the drawings

The following drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but do not constitute a limitation of the present invention.

Figure 1 is a process flow diagram for producing low-sulfur marine residual fuel oil from low-sulfur paraffin-based crude oil according to one embodiment of the present invention;

Figure 2 is a schematic connection diagram of the process flow and device for producing low-sulfur marine residual fuel oil from low-sulfur paraffin-based crude oil according to one embodiment of the present invention.

Among them, the reference symbols are explained as follows:

1: Low sulfur paraffin-based crude oil

2: Secondary processing of inferior heavy oil

3: Always be angry

4: Naphtha

5: Straight run diesel

6: Light wax oil

7: Normal pressure residual oil

8: Heavy wax oil

9: Deep pulling of atmospheric residual oil

10: Low sulfur marine residual fuel oil

40: Heating furnace

50: Normal pressure distillation tower

60: Pressure reduction flash tank

70: Fuel oil mixing tank

Detailed ways

The following content provides different embodiments or examples so that those skilled in the art can implement them according to the text of the description. Of course, these are merely examples and are not intended to limit the invention. The endpoints of ranges and any values disclosed in this disclosure are not limited to the precise range or value, but these ranges or values are to be understood to include values approximating those ranges or values. For numerical ranges, the endpoint values of each range, the endpoint values of each range and individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges. These values The scope should be deemed to be specifically disclosed herein.

Figure 1 shows a process flow diagram for producing low-sulfur marine residue fuel oil from low-sulfur paraffin-based crude oil according to one embodiment of the present invention. As shown in Figure 1, the present invention provides a method for producing low-sulfur marine residue from low-sulfur paraffin-based crude oil. The method of fuel oil includes: mixing low-sulfur paraffin-based crude oil with secondary processed inferior heavy oil and then performing atmospheric distillation to obtain naphtha, straight-run diesel, light wax oil and atmospheric residual oil respectively; the atmospheric residual oil is processed by After separation by flash evaporation under reduced pressure, heavy wax oil and deep-drawn atmospheric pressure residue are obtained; and the deep-drawn atmospheric pressure residue is mixed with straight-run diesel to obtain low-sulfur marine residual fuel oil.

Those skilled in the art know that pour point refers to the lowest temperature at which a cooled sample of oil can flow under specified test conditions. That is, the lower the pour point, the better the low-temperature fluidity of the oil. The inventor's research has found that after directly distilling low-sulfur paraffin-based crude oil through a conventional atmospheric distillation tower, the atmospheric residue cut out has a pour point greater than 50°C. Even if the atmospheric residue is mixed with -10 No. catalytic diesel is mixed in a 50:50 ratio, and the pour point is still greater than 45°C. After crude oil is distilled, the yield of atmospheric residual oil is generally 40% to 70%. As the most important primary processing product, it accounts for nearly half. However, the atmospheric residual oil obtained by existing methods has a high pour point and poor oil fluidity, making it difficult for refineries to prepare a large amount of other secondary processing oils (such as catalytic diesel, slurry, hydrogenated diesel, etc.) to blend with it. Produces low sulfur marine residual fuel oil.

At the same time, further research found that when low-sulfur paraffin-based crude oil is refined and cut into sections, the components with higher freezing points and pour points are mainly concentrated in light wax oil with a distillation range of 330°C to 370°C and a distillation range of 370°C. Among the heavy wax oils at ~460°C, the wax content is the highest among these two fractions. If separated, the pour point of atmospheric residual oil can be significantly reduced. After further experimental research, the low-sulfur paraffin-based crude oil can indeed increase the production of light wax oil with a distillation range of 330°C to 370°C and heavy wax oil with a distillation range of 370°C to 460°C after atmospheric distillation and flash evaporation under reduced pressure. The extraction rate increases the 5% distillation point temperature of the remaining atmospheric residue and reduces the wax content in the atmospheric residue. However, whether it is a laboratory distillation device or an industrial atmospheric pressure device and a pressure reducing device, during the distillation and cutting process, there are temperatures with overlapping distillation ranges of two adjacent components, that is, they will always remain in the atmospheric pressure residue. A certain amount of light wax oil components with a distillation range of 330°C to 370°C, and deep-drawing atmospheric pressure residual oil will always retain a certain amount of heavy wax oil components with a distillation range of 370°C to 460°C, which is helpful for reducing the atmospheric pressure residual oil. pour point, further production of low-sulfur marine residual fuel oil that meets the requirements is very unfavorable.

To this end, the present invention provides a new method for producing low-sulfur marine residual fuel oil from low-sulfur paraffin-based crude oil. This method uses secondary-processed inferior heavy oil and low-sulfur paraffin-based crude oil to be mixed as raw materials. The introduced secondary-processed inferior heavy oil The distillation range overlaps with the distillation range of light wax oil and heavy wax oil in crude oil. During the normal pressure distillation and vacuum flash evaporation process, under the same overlap condition, the secondary processing of inferior heavy oil can convert part of the light wax oil from normal Part of the heavy wax oil is replaced from the pressure residue oil, and part of the heavy wax oil is replaced from the deep-drawn atmospheric pressure residue oil; at the same time, due to the high aromatic content of secondary processing of inferior heavy oil, the aromatic hydrocarbon content in the atmospheric pressure residue and deep-drawn atmospheric pressure residue oil According to the similar compatibility principle, secondary processed inferior heavy oil is more likely to remain in the deep-drawn atmospheric pressure residue oil, replacing the heavy wax oil. The obtained deep-drawn atmospheric residue with reduced wax content and pour point is further mixed with the straight-run diesel cut out in the atmospheric distillation in a certain proportion. Since the pouring point and sulfur content of straight-run diesel in low-sulfur paraffin-based crude oil are relatively Low sulfur marine residual fuel oil can be directly mixed with deep-drawn atmospheric pressure residual oil to obtain low-sulfur marine residual fuel oil, thus greatly increasing the production of low-sulfur marine residual fuel oil.

Figure 2 shows a schematic connection diagram of the process flow and equipment for producing low-sulfur marine residual fuel oil from low-sulfur paraffin-based crude oil according to one embodiment of the present invention. The method of producing low-sulfur marine residual fuel oil from low-sulfur paraffin-based crude oil will be described in detail below in conjunction with Figures 1 and 2. Methods for sulfur marine residual fuel oil.

As shown in Figure 2, first, low-sulfur paraffin-based crude oil 1 and secondary processed inferior heavy oil 2 are premixed through the pipeline. Among them, the properties of low-sulfur paraffin-based crude oil 1 are that the sum of the content of gum and asphaltene is less than 10wt%, for example, 1wt%, 2wt%, 5wt%, 7wt%, 8wt%, 8.5wt%, 9wt%, etc. The wax content of low-sulfur paraffin-based crude oil is 25wt% to 35wt%, for example, 25wt%, 27wt%, 29wt%, 30wt%, 32wt%, 34wt%, 35wt%, etc., and the sulfur content is less than 0.35wt%, for example, 0.05 wt%, 0.1wt%, 0.2wt%, 0.3wt%, etc., the freezing point is 30°C to 36°C, for example, 30°C, 31°C, 34°C, 35°C, etc., and the pour point is 33°C to 40°C, for example, 33℃, 34℃, 35℃, 36℃, 38℃, 39℃, etc. The aromatics content of the secondary processed inferior heavy oil 2 is preferably 37wt% to 75wt%, for example, 40wt%, 45wt%, 50wt%, 60wt%, 70wt%, etc., and the sulfur content is less than 0.5wt%, for example, 0.1wt%, 0.2wt %, 0.3wt%, 0.4wt%, etc., the distillation range is preferably 330°C to 480°C, for example, 330°C, 350°C, 400°C, 420°C, 460°C, 470°C, 480°C, etc.

In some embodiments, the secondary processed low-quality heavy oil 2 is selected from one or more of catalytically cracked diesel, coked diesel, catalytically cracked recycled oil, desolidified catalytic cracked oil slurry, hydrogenated catalytically cracked diesel, and coal tar. kind. By mixing the aforementioned secondary processed inferior heavy oil 2 with the low-sulfur paraffin-based crude oil 1 as a distillation raw material, the wax in the atmospheric residue obtained after atmospheric distillation and vacuum flash separation and the deep-drawn atmospheric residue can be reduced The residual amount reduces the overlap of wax oil, thereby obtaining deep-drawn atmospheric pressure residual oil with lower wax content and pour point.

In some embodiments, in order to achieve the above purpose, it is necessary to control the mixing ratio of low-sulfur paraffin-based crude oil 1 and secondary processed inferior heavy oil 2, wherein the mass ratio of the two is preferably 95:5 to 85:15, for example, 95 :5, 90:10, 80:5, 80:15, etc. Too high a proportion of secondary processed inferior heavy oil 2 will increase the load of atmospheric distillation and vacuum flash evaporation, and reduce the production of low-sulfur paraffin-based crude oil 1 , and more importantly, although the solidification point and pour point of secondary processed inferior heavy oil 2 are lower (such as catalytic cracking heavy cycle oil, catalytic cracked heavy diesel oil), its viscosity is also low. If the proportion of secondary processed inferior heavy oil 2 is too If the value is high, the low-viscosity components remaining in the deep-drawn atmospheric pressure residue after distillation will increase, which will affect the viscosity properties of the deep-drawn atmospheric pressure residue. The viscosity properties are also important indicators of low-sulfur marine residue fuel oil, so it is necessary to control the appropriate effects. The blending ratio of secondary processed inferior heavy oil 2.

As shown in FIG. 2 , next, the aforementioned mixed low-sulfur paraffin-based crude oil 1 and secondary processed inferior heavy oil 2 enter the heating furnace 40 to be heated and then introduced into the atmospheric distillation tower 50 . The normal pressure distillation tower 50 is distilled and cut and drawn through pipelines to obtain the normal overhead gas 3, naphtha 4, straight-run diesel oil 5, light wax oil 6 and normal pressure residual oil 7 respectively.

Among them, the distillation range of the aforementioned naphtha is 30-250°C, the distillation range of straight-run diesel is 200-350°C, the distillation range of light wax oil is 330-390°C, and the distillation range of atmospheric residual oil is 5% by volume. The distillation point temperature is not less than 370℃.

In addition, those skilled in the art know that the atmospheric pressure distillation tower generally achieves the distillation of oil products in the tower by heating the atmospheric pressure furnace therein. For the present invention, the atmospheric pressure furnace outlet temperature of the atmospheric pressure distillation tower 50 is preferably 370°C. ~390℃, for example, 370℃, 375℃, 380℃, 388℃, 390℃, etc.

As shown in Figure 2, further, after atmospheric distillation, it also includes directly connecting the atmospheric residue extraction line at the bottom of the atmospheric distillation tower 50 to the newly installed vacuum flash tank 60 to perform vacuum flash separation. The heavy wax oil 8 is produced, and the wax content of the atmospheric pressure residue 7 is further reduced to obtain the deep-drawn atmospheric pressure residue 9, which can significantly reduce the pour point of the deep-drawn atmospheric pressure residue.

Specifically, the pressure of decompression flash evaporation is 7kpa to 20kpa, for example, 7kpa, 10kpa, 12kpa, 15kpa, 20kpa, etc., where the aforementioned "pressure" refers to absolute pressure. The distillation range of the heavy wax oil 8 is 370-460°C, and the distillation range of the deep-drawn atmospheric pressure residue oil 9 is 5% volume distillation point with a temperature of not less than 390°C, preferably not less than 400°C.

Finally, as shown in Figure 2, the above-obtained deep-drawn atmospheric pressure residual oil 9 and a part of the above-described straight-run diesel oil 6 obtained by distillation are mixed in proportion in the fuel oil mixing tank 70 to obtain low-sulfur marine residual fuel oil 10. Since the freezing point and sulfur content of straight-run diesel oil with a medium distillation range of 200 to 350°C in low-sulfur paraffin-based crude oil 1 is relatively low, it can be directly mixed with deep-drawn atmospheric residual oil 9 to obtain low-sulfur marine residual fuel oil, which greatly improves the Production of low sulfur marine residual fuel oil.

Among them, the mass ratio of deep-drawn atmospheric residual oil and straight-run diesel oil is 90:10 to 70:30, for example, 90:10, 80:10, 80:20, 70:10, 70:15, 70:30, etc. . The low-sulfur marine residual fuel oil obtained by this method has a sulfur content of less than 0.5wt% and a pour point of less than 30°C.

In some embodiments, optionally, it also includes mixing the aforementioned low-sulfur marine residual fuel oil 10 with other marine residual fuel oil blending components to further increase the production of marine residual fuel oil, wherein other marine residual fuel oil The fuel oil is selected from one or more of hydrogenated heavy oil, hydrogenated diesel, catalytically cracked diesel, coked diesel, catalytically cracked recycled oil, desolidified catalytic cracked oil slurry, hydrogenated catalytically cracked diesel and coal tar.

In summary, the present invention obtains atmospheric residual oil by mixing paraffin-rich low-sulfur paraffin-based crude oil and secondary processed inferior heavy oil in a certain proportion and performing atmospheric distillation. The atmospheric residual oil is further subjected to vacuum flash separation to obtain deep-seated crude oil. To extract atmospheric residual oil, the distillation range of introduced secondary processing inferior heavy oil rich in aromatics overlaps with the distillation range of light wax oil and heavy wax oil in crude oil. In the process of atmospheric distillation and vacuum flash evaporation, Under the same degree of overlap, this secondary processing of inferior heavy oil can replace part of the light wax oil from the atmospheric residual oil, and replace part of the heavy wax oil from the deep drawn atmospheric residual oil, thereby reducing the amount of atmospheric residual oil and The remaining amount of wax in the deep-drawn atmospheric pressure residue is reduced to reduce the overlap of the wax oil, and a deep-drawn atmospheric pressure residue with lower wax content and pour point is obtained. At the same time, part of the straight-run diesel obtained after the distillation of low-sulfur paraffin-based crude oil is mixed with the deep-drawn atmospheric pressure residual oil to obtain low-sulfur marine residual fuel oil. The low-sulfur marine residual fuel oil obtained by this method has the advantages of high yield, low pour point, and low paraffin content. It solves the problem that low-sulfur paraffin-based crude oil cannot be used to produce RMG180 in compliance with GB17411-2015 because it is rich in paraffin and has a high freezing point. The low-sulfur marine residual fuel oil specified in the index has low investment costs, reduces other secondary processing costs, and has good application prospects.

The present invention will be further described below through examples, but the present invention is not limited thereby. Unless otherwise specified, the reagents or materials used in the present invention can all be purchased from the market.

In the following examples, a medium-sized normal pressure distillation device and a medium-sized vacuum flash evaporation device are used in combination. Among them, the distillation section of the atmospheric distillation unit has an inner diameter of 50 mm and a height of 1500 mm. It is equipped with packing and the bottom column kettle adopts electric heating mode; the distillation section of the vacuum flash evaporation unit has an inner diameter of 50 mm and a height of 1500 mm. There is no filler. The top outlet of the tower is connected to a mechanical vacuum pump. The vacuum pressure can be as low as 0.1Kpa. The bottom kettle adopts electric heating mode to achieve decompression flash evaporation.

Example 1

1) Mix low-sulfur paraffin-based crude oil and secondary processed inferior heavy oil evenly at a mass ratio of 90:10 at 70°C. Among them, the low-sulfur paraffin-based crude oil used is the low-sulfur paraffin-based crude oil from the Subei Oilfield, and its properties are shown in Table 1; the secondary processing of inferior heavy oil uses light oil slurry after desolidification, and its properties are shown in Table 2. The mixed low-sulfur paraffin-based crude oil and secondary processed inferior heavy oil are sent to the bottom column kettle of the atmospheric distillation device, heated and distilled under normal pressure conditions, and naphtha, straight-run diesel oil, and light wax oil are cut out in sequence, and the remaining The bottom of the kettle is residual oil under normal pressure. Among them, the operating conditions of the atmospheric distillation unit are: the atmospheric furnace outlet temperature is 380°C, and the tower top pressure is 101kpa (absolute pressure).

2) The atmospheric pressure residue obtained in step 1) is further sent to a decompression flash evaporation device, heated and a mechanical vacuum pump is used to control the distillation pressure, and the heavy wax oil is cut out. The remaining bottom of the kettle is deep-drawn atmospheric pressure residue. Among them, the operating conditions of the vacuum flash evaporation device are: the outlet temperature of the bottom tower kettle is 380°C, and the top pressure is 9kpa (absolute pressure).

3) Mix the deep-drawn atmospheric pressure residual oil obtained in step 2) and the straight-run diesel oil obtained in step 1) at a mass ratio of 85:15 at 70°C to obtain low-sulfur marine residual fuel oil.

The specific operating conditions, raw materials and properties of the obtained low-sulfur marine residual fuel oil of Example 1 are shown in Table 3.

Example 2

The experimental device, method and crude oil of Example 2 are the same as those of Example 1. The main difference is that the secondary processing of inferior heavy oil uses catalytic cracking heavy cycle oil produced through a catalytic cracking unit. The properties are shown in Table 2. The specific operating conditions, raw materials and properties of the obtained low-sulfur marine residual fuel oil of Example 2 are shown in Table 3.

Example 3

The experimental device, method and crude oil of Example 3 are the same as those of Example 1. The main difference is that the secondary processing of inferior heavy oil uses desolidified oil slurry produced by a catalytic cracking unit and catalytically cracked heavy diesel oil. The two are mixed in a ratio of 1:1. The properties are shown in Table 2. The specific operating conditions, raw materials, and properties of the obtained low-sulfur marine residual fuel oil of Example 3 are shown in Table 3.

Comparative example 1

Experiments were conducted using a medium-sized atmospheric distillation device. Among them, the distillation section of the atmospheric distillation unit has an inner diameter of 50 mm and a height of 1500 mm. It is equipped with packing and the bottom kettle adopts electric heating mode. Compared with the previous embodiments, Comparative Example 1 only uses a normal pressure distillation device to perform distillation under normal operating conditions. Before the low-sulfur paraffin-based crude oil enters the normal pressure distillation device, it is not mixed with secondary processed inferior heavy oil. Specifically, :

1) Send the low-sulfur paraffin-based crude oil into the bottom column kettle of the atmospheric distillation unit, heat and distill under normal pressure conditions, and cut out naphtha, straight-run diesel, and light wax oil in sequence, and the remaining bottom of the kettle is atmospheric residual oil. . Among them, the operating conditions of the atmospheric distillation unit are: the atmospheric furnace outlet temperature is 360°C, and the tower top pressure is 101kpa (absolute pressure).

2) Mix normal pressure residual oil and straight-run diesel oil at a mass ratio of 85:15 at 70°C to obtain low-sulfur marine residual fuel oil.

The specific operating conditions, raw materials, and properties of the obtained low-sulfur marine residual fuel oil of Comparative Example 1 are shown in Table 3.

Comparative example 2

Experiments were conducted using a medium-sized device with atmospheric pressure distillation. Among them, the distillation section of the atmospheric distillation unit has an inner diameter of 50 mm and a height of 1500 mm. It is equipped with packing and the bottom kettle adopts electric heating mode.

1) Send the low-sulfur paraffin-based crude oil into the bottom column kettle of the atmospheric distillation unit, heat and distill under normal pressure conditions, and cut out naphtha, straight-run diesel, and light wax oil in sequence, and the remaining bottom of the kettle is atmospheric residual oil. . Among them, the operating conditions of the atmospheric distillation unit are: the atmospheric furnace outlet temperature is 380°C, and the tower top pressure is 101kpa (absolute pressure).

2) Mix normal pressure residual oil with straight-run diesel and secondary processed inferior heavy oil at a mass ratio of 80:15:5 at 100-200°C to obtain low-sulfur marine residual fuel oil.

The specific operating conditions, raw materials, and properties of the obtained low-sulfur marine residual fuel oil of Comparative Example 2 are shown in Table 3.

Comparative example 3

The experimental device, method, crude oil and specific operating conditions of Comparative Example 3 are the same as those in Example 1. The difference is that the outlet temperature of the atmospheric furnace of the atmospheric distillation tower is 360°C.

Table 1

Table 2

table 3

As can be seen from Table 3 above, Example 1 uses the low-sulfur paraffin base from the Subei Oilfield as raw material. Through the method of the present invention, low-sulfur marine residual fuel oil that meets the RMG180 index in GB17411-2015 can be produced, with a sulfur content of no more than 0.5 % by weight, the pour point is not greater than 30°C; in Comparative Example 1, the low-sulfur marine residual fuel oil produced by using the low-sulfur paraffin base from the Subei Oilfield as raw material and using conventional distillation cutting and blending methods has a pour point greater than 30°C. It cannot leave the factory. In Comparative Example 2, the low-sulfur marine residual fuel oil produced by using the low-sulfur paraffin base from the Subei Oilfield as raw material and using improved conventional distillation, cutting and blending methods still has a pour point greater than 30°C and cannot leave the factory. In Examples 2 and 3, by using the method provided by the present disclosure and using the low-sulfur paraffin base from the Subei Oilfield as raw material, it is also possible to produce low-sulfur marine residual fuel oil that meets the RMG180 index in GB17411-2015.

Comparative Example 3 uses the same method as Example 1, but the outlet temperature of the atmospheric furnace of the atmospheric distillation tower is 360°C, which is lower than the optimal range, resulting in part of the heavy wax oil remaining in the deep-drawn atmospheric pressure residue oil, causing the mixing Although the pour point of the later low-sulfur marine residual fuel oil has been reduced, it cannot meet the index pour point of RMG180 specified in GB17411-2015 of not greater than 30°C.

Those skilled in the art should note that the described embodiments of the present invention are exemplary only, and various other substitutions, changes and improvements can be made within the scope of the present invention. Therefore, the present invention is not limited to the above-described embodiments, but only by the claims.

Claims (3)

1. A method for producing low-sulfur marine residual fuel oil using low-sulfur paraffin-based crude oil, which is characterized by including: Mix low-sulfur paraffin-based crude oil with secondary processed inferior heavy oil and perform atmospheric distillation to obtain naphtha, straight-run diesel, light wax oil and atmospheric residual oil respectively; The sum of the colloid and asphaltene contents in the low-sulfur paraffin-based crude oil is less than 10wt%, the wax content of the low-sulfur paraffin-based crude oil is 25wt% to 35wt%, the sulfur content is less than 0.35wt%, and the freezing point is 30 ℃～36℃, pour point is 33℃～40℃; The mass ratio of the low-sulfur paraffin-based crude oil to the secondary-processed inferior heavy oil is 95:5 to 85:15; The atmospheric distillation is carried out in an atmospheric distillation tower, and the atmospheric furnace outlet temperature of the atmospheric distillation tower is 370°C to 390°C; The aromatic content of the secondary processed inferior heavy oil is 37wt% to 75wt%, the sulfur content is less than 0.5wt%, and the distillation range is 330°C to 480°C; The secondary processed inferior heavy oil is selected from one or more of catalytic cracking diesel, coked diesel, catalytic cracking recycled oil, desolidified catalytic cracking oil slurry, hydrogenated catalytic cracking diesel and coal tar; After the atmospheric pressure residue oil is separated by flash evaporation under reduced pressure, heavy wax oil and deep-drawn atmospheric pressure residue oil are obtained; and Mix the deep-drawn atmospheric pressure residual oil with the straight-run diesel oil to obtain the low-sulfur marine residual fuel oil; The mass ratio of the deep-drawn atmospheric residual oil and the straight-run diesel oil is 90:10 to 70:30; The distillation range of the naphtha is 30-250°C, the distillation range of the straight-run diesel oil is 200-350°C, the distillation range of the light wax oil is 330-390°C, and the distillation range of the atmospheric residual oil is The distillation point temperature of 5% volume is not less than 370℃; The distillation range of the heavy wax oil is 370-460°C, and the distillation range of the deep-drawn atmospheric pressure residual oil is 5% volume distillation point with a temperature not less than 390°C. 2. The method according to claim 1, characterized in that the pressure of the reduced pressure flash evaporation is 7kpa～20kpa. 3. The method according to claim 1, characterized in that after the deep-drawn atmospheric pressure residue oil is mixed with straight-run diesel oil, it also includes adding other marine residual fuel oil and mixing to obtain the low-sulfur marine residual fuel oil; Wherein, the other marine residual fuel oil is selected from the group consisting of hydrogenated heavy oil, hydrogenated diesel, catalytically cracked diesel, coked diesel, catalytically cracked refining oil, desolidified catalytic cracked oil slurry, hydrogenated catalytically cracked diesel and coal tar. of one or more.