Hydrogenated coal tar, low-sulfur heavy marine fuel oil prepared therefrom and preparation method thereof

Abstract

The present invention belongs to the technical field of marine fuel oil, and specifically relates to a hydrogenated coal tar, and the use of high-temperature / low-quality coal tar to prepare low-sulfur heavy marine fuel oil, and further discloses its preparation method. The hydrogenated high-temperature / low-quality coal tar of the present invention is pre-treated by demulsifier sedimentation, and the high-temperature low-quality coal tar after ebullient bed hydrogenation treatment does not need to be separated and fractionated, and can be directly used as a blending component of marine residual fuel oil. The low-sulfur heavy marine residual fuel oil of the present invention uses residual oil, catalytic oil slurry, hydrogenated coal tar and diesel as blending components, and has the advantage of a low sulfur content in the product.

Description

Technical Field

[0001] The invention belongs to the technical field of marine fuel oil, and specifically relates to a hydrogenated coal tar, and the application of high-temperature / low-quality coal tar in preparing low-sulfur heavy marine fuel oil, and further discloses a preparation method thereof. Background Art

[0002] According to the current marine fuel oil standard GB17411-2015, when a ship is sailing in a general area at sea, the sulfur content of heavy marine fuel oil should not exceed 0.5%, and it should also meet the specific requirements of each port. Moreover, with the increasing severity of air pollution, it is urgent to reduce ship pollutant emissions. At present, the measures to reduce ship pollutant emissions mainly include switching to low-sulfur fuel oil, adding ship after-treatment equipment, reducing ship speed, using alternative fuels, and establishing emission control areas. Among them, the use of low-sulfur fuel oil is the most effective and simplest measure to reduce pollutant emissions.

[0003] At present, the process routes for producing low-sulfur residual marine fuel oil with a sulfur content of less than 0.5% mainly include: (1) replacing low-sulfur crude oil, that is, using atmospheric residue oil or vacuum residue oil to blend low-sulfur marine fuel oil after cutting, among which atmospheric residue oil can be produced directly; while vacuum residue oil has a high viscosity, it needs to use visbreaking devices to reduce the viscosity, or it needs to be blended with catalytic diesel, catalytic oil slurry, etc. Considering the high price of low-sulfur crude oil and limited resources, the production cost of residual marine fuel will be increased; (2) desulfurization of high-sulfur residual oil, that is, using low-sulfur secondary processed residual oil to blend and produce residual marine fuel. Although this process route is rich in resources, the desulfurization cost is relatively high. Therefore, using low-value-added products as blending components to effectively reduce the blending cost of blended marine fuel oil is an important task in the current research and development and production of marine fuel oil.

[0004] The current energy situation in my country is rich in coal and less in oil, and there is a phenomenon of excess coal tar. However, due to the complex properties and poor stability of coal tar, it is difficult to directly blend with marine fuel oil, especially high-temperature coal tar or low-quality coal tar, which has higher impurities, ash and other contents, and is more difficult to process and utilize. The prior art reports a process in which high-temperature / low-quality coal tar is pretreated and then hydrogenated in a fluidized bed, and can be directly used as a blending component oil for marine fuel oil. Due to the good low-temperature flowability and low sulfur content of hydrogenated coal tar, after adding hydrogenated coal tar, not only can the amount of catalytic raw material VRDS residue oil be reduced, and the catalytic cracking capacity be increased, but also the amount of low value-added product catalytic oil slurry can be increased, thereby improving economic benefits. It is an effective means of reusing high-temperature low-quality coal tar.

[0005] However, the difficulty of the high-temperature / low-quality coal tar hydrogenation process lies in the fact that coal tar has high density and viscosity, poor fluidity, and especially high content of residual carbon, ash, mechanical impurities, metals, etc. These impurities can easily cause the catalyst to coke and deactivate. In severe cases, they can also clog the reactor bed, shorten the device operation cycle, and seriously affect the oil product properties. Therefore, in the high-temperature low-quality coal tar dehydrogenation process, the impurity removal pretreatment process is a key step in the entire process processing. Only by ensuring the effective removal of impurities in coal tar can the production of subsequent fuel oil be provided with a basis and guarantee. Most of the existing pretreatment technologies are suitable for medium and low-temperature coal tar, but not for high-temperature low-quality coal tar.

[0006] For example, the coal tar pretreatment method disclosed in Chinese patent CN101838550A includes mixing coal tar with extractant A and heating to 50-150°C, wherein the extractant A is one or more of diesel, kerosene or an intermediate distillate oil of hydrogenated oil from a coal tar hydrogenation unit, and then separating the obtained mixed liquid into soluble matter and impurity-containing extraction insoluble matter by a sedimentation centrifuge. However, the centrifugal separation method directly used after extraction will cause the separator to be blocked and the filtration efficiency to be low, making it difficult to effectively remove impurities from coal tar. Another example is the coal tar catalytic hydrogenation treatment method for producing high-yield light clean fuel oil disclosed in Chinese patent CN101724461A. The method pre-fractionates coal tar to remove heavy components such as asphalt, heavy metal salts and solid impurities, and then cuts fractions less than 300°C and 300-380°C as hydrogenation feed oil, and then reacts the two fractions in different reactors. However, the method does not fully utilize coal tar, and the economic benefits are not ideal. Summary of the invention

[0007] To this end, the technical problem to be solved by the present invention is to provide a hydrogenated high-temperature / low-quality coal tar, which can be directly used as a blending component of marine fuel after pretreatment and ebullating bed hydrogenation treatment, and has the advantages of simple process, energy saving, convenient operation, reduced sulfur content, increased catalytic oil slurry transfer amount, reduced cost and increased efficiency;

[0008] The second technical problem to be solved by the present invention is to provide a low-sulfur heavy marine fuel oil prepared by blending high-temperature inferior coal tar with hydrogenation, which has the advantage of low sulfur content and meets increasingly stringent environmental protection requirements.

[0009] In order to solve the above technical problems, a method for preparing hydrogenated coal tar according to the present invention comprises the following steps:

[0010] (1) taking the coal tar to be processed, adding diluent oil and mixing to obtain the raw material oil, and setting aside;

[0011] (2) adding a demulsifier and a sedimentation agent to the crude oil in sequence, and heating the crude oil to 40-70° C. for treatment;

[0012] (3) Extract 95% of the raw oil from the upper layer, filter it, and introduce the entire fraction into a hydrogenation unit for hydrogenation treatment to obtain the product.

[0013] Specifically, in the method for preparing hydrogenated coal tar, in step (1):

[0014] The diluent oil includes catalytic diesel;

[0015] The mass ratio of the coal tar to the diluent oil is 1:0.1-1.0.

[0016] Specifically, in the method for preparing hydrogenated coal tar, in step (2):

[0017] The demulsifier comprises a mixture of alkylphenol formaldehyde resin polyoxypropylene polyoxyethylene ether and xylene in a mass ratio of 5%-15%:85%-95%; preferably a mixture of alkylphenol formaldehyde resin polyoxypropylene polyoxyethylene ether and xylene in a mass ratio of 10%:90%;

[0018] The added amount of the demulsifier is 100-200 ppm.

[0019] Preferably, after adding the demulsifier, stirring is performed at a medium speed for 20-30 minutes to perform demulsification treatment.

[0020] Specifically, in the method for preparing hydrogenated coal tar, in step (2):

[0021] The sedimentation agent comprises a mixture of fatty alcohol polyoxyethylene ether, polyacrylamide and glycerol in a mass ratio of 18%-24%: 65%-75%: 6%-10%; preferably a mixture of fatty alcohol polyoxyethylene ether, polyacrylamide and glycerol in a mass ratio of 22%: 70%: 8%;

[0022] The added amount of the sedimentation agent is 100-400ppm.

[0023] Preferably, after adding the sedimentation agent, high-speed stirring is performed for 30-60 minutes to carry out sedimentation treatment.

[0024] Specifically, in the step (2), the sedimentation treatment is followed by standing for 24 hours.

[0025] Specifically, in step (3), the filtration step is ceramic membrane filtration, and the effective filtration accuracy of the ceramic membrane tube is controlled to be 2-10 μm, preferably 6-10 μm.

[0026] Specifically, in step (3), the hydrogenation device is an ebullated bed hydrogenation device;

[0027] The process parameters of the hydroprocessing step include: reaction pressure of 12-14MPa, hydrogen-to-oil volume ratio of 350-450:1, reaction temperature of 330-370°C; preferably, the reaction pressure is 13MPa, the hydrogen-to-oil volume ratio is 400:1, and the reaction temperature is 350°C.

[0028] Specifically, in step (1), the coal tar includes high-temperature coal tar and / or low-quality coal tar.

[0029] The present invention also discloses a low-sulfur heavy marine fuel oil prepared based on the hydrogenated coal tar, comprising the following components in parts by weight:

[0030] 50-80 parts by weight of residual oil;

[0031] 5-20 parts by weight of catalytic slurry;

[0032] 5-25 parts by weight of hydrogenated coal tar;

[0033] 2-10 parts by weight of diesel.

[0034] Specifically, the low-sulfur heavy marine fuel oil:

[0035] The residual oil includes hydrogenated residual oil; preferably, the density at 20°C is 880-980kg / m 3 , flash point greater than 130°C, sulfur content less than 0.5%;

[0036] The diesel oil includes catalytic diesel oil, ethylene diesel oil, coking diesel oil or a mixture of the above, preferably catalytic diesel oil, preferably with a density of 920-1020 kg / m3 at 20°C. 3 , flash point greater than 45°C, aluminum silicon content less than 30 mg / kg;

[0037] The catalytic slurry preferably has a density of 1000-1200 kg / m 3 , flash point is greater than 130℃, aluminum silicon content is 100-400mg / kg.

[0038] The present invention also discloses a method for preparing the low-sulfur heavy marine fuel oil, comprising the step of blending selected amounts of the residual oil, catalytic oil slurry, hydrogenated coal tar and diesel at 50-60° C. Preferably, the blending is performed by stirring at a speed of 50-100 rpm for 50-60 minutes.

[0039] The hydrogenated high-temperature / low-quality coal tar of the present invention effectively reduces impurities, ash and carbon residue in the coal tar through a pretreatment method of demulsifier sedimentation. The high-temperature low-quality coal tar after the ebullated bed hydrogenation treatment does not need to be separated and fractionated, and can be directly used as a blending component of marine residual fuel oil, effectively solving the technical bottleneck that the high-temperature low-quality coal tar is difficult to be subsequently processed and applied due to the high solid impurity content, achieving low-quality and high-performance use of the high-temperature low-quality coal tar, and reducing production costs.

[0040] The low-sulfur heavy marine residual fuel oil of the present invention uses residual oil, catalytic oil slurry, hydrogenated coal tar and diesel as blending components. The high-temperature inferior coal tar after hydrogenation treatment can replace part of VRDS residual oil for blending marine fuel, thereby reducing the amount of VRDS regular residue, a raw material for catalytic cracking, and improving the catalytic cracking capacity. It has the advantages of simple process, energy saving and convenient operation, and can effectively reduce the sulfur content of marine fuel products and increase the amount of catalytic oil slurry added, thus meeting increasingly stringent environmental protection requirements, effectively reducing production costs and increasing benefits. DETAILED DESCRIPTION

[0041] In the following embodiments of the present invention, the components involved include:

[0042] The residual oil is hydrogenated residual oil, and its density at 20°C is 880-980kg / m 3 , flash point greater than 130°C, sulfur content less than 0.5%;

[0043] The diesel is selected from catalytic diesel, ethylene diesel or coking diesel, and its density at 20°C is 920-1020 kg / m 3 , flash point greater than 45°C, aluminum silicon content less than 30 mg / kg;

[0044] The density of the catalytic slurry at 20°C is 1000-1200 kg / m 3 , flash point greater than 130°C, aluminum silicon content of 100-400mg / kg;

[0045] The demulsifier is a mixture of 10 wt% of alkylphenol formaldehyde resin polyoxypropylene polyoxyethylene ether and 90 wt% of xylene;

[0046] The sedimentation agent is a mixture of 22 wt % fatty alcohol polyoxyethylene ether, 70 wt % polyacrylamide, and 8 wt % glycerol.

[0047] Preparation Example 1

[0048] The coal tar hydrogenation pretreatment method described in this preparation example comprises the following steps:

[0049] (1) Weigh high-temperature low-quality coal tar and catalytic diesel in a mass ratio of 1:0.1, mix them evenly, heat them to 60° C., and stir them at a medium speed for 30 minutes until they are fully mixed, to obtain a crude oil;

[0050] (2) Add 150 ppm of demulsifier to the above-mentioned crude oil, maintain the temperature at 60° C. and stir at medium speed for 20 min; continue to add 300 ppm of sedimentation agent, maintain the temperature at 60° C. and stir at high speed for 30 min until fully mixed, and let it stand for 24 hours;

[0051] (3) 95% of the crude oil in the upper layer is extracted and filtered through a 10 μm ceramic membrane filter to obtain the product.

[0052] Preparation Example 2

[0053] The coal tar hydrogenation pretreatment method described in this preparation example comprises the following steps:

[0054] (1) Weigh high-temperature low-quality coal tar and catalytic diesel in a mass ratio of 1:0.2, mix them evenly, heat them to 60° C. and stir them at a medium speed for 30 minutes until they are fully mixed, to obtain a crude oil;

[0055] (2) adding 100 ppm of demulsifier to the above-mentioned crude oil, stirring at medium speed for 30 min at 60° C. until fully mixed; continuing to add 100 ppm of sedimentation agent, stirring at high speed for 60 min at 60° C. until fully mixed, and letting stand for 24 hours;

[0056] (3) 95% of the crude oil in the upper layer is extracted and filtered through a 10 μm ceramic membrane filter to obtain the product.

[0057] Preparation Example 3

[0058] The coal tar hydrogenation pretreatment method described in this preparation example comprises the following steps:

[0059] (1) Weigh high-temperature low-quality coal tar and catalytic diesel in a mass ratio of 1:0.4, mix them, heat them to 60° C., and stir them at a medium speed for 30 minutes until they are fully mixed, to obtain a crude oil;

[0060] (2) Add 120 ppm of demulsifier to the above-mentioned crude oil, maintain the temperature at 60° C. and stir at medium speed for 30 min until fully mixed; continue to add 300 ppm of sedimentation agent, maintain the temperature at 60° C. and stir at high speed for 40 min until fully mixed, and let it stand for 24 hours;

[0061] (3) 95% of the crude oil in the upper layer is extracted and filtered through an 8 μm ceramic membrane filter to obtain the product.

[0062] Preparation Example 4

[0063] The coal tar hydrogenation pretreatment method described in this preparation example comprises the following steps:

[0064] (1) Weighing high-temperature low-quality coal tar and catalytic diesel in a mass ratio of 1:0.7, mixing them, heating them to 60° C. and stirring them at a medium speed for 30 minutes until they are fully mixed, to obtain a crude oil;

[0065] (2) Add 150 ppm of demulsifier to the above-mentioned crude oil, maintain the temperature at 60° C. and stir at medium speed for 30 minutes until fully mixed; continue to add 200 ppm of sedimentation agent, maintain the temperature at 60° C. and stir at high speed for 45 minutes until fully mixed, and let it stand for 24 hours;

[0066] (3) 95% of the crude oil in the upper layer is extracted and filtered through a 6 μm ceramic membrane filter to obtain the product.

[0067] Preparation Example 5

[0068] The coal tar hydrogenation pretreatment method described in this preparation example comprises the following steps:

[0069] (1) Weigh high-temperature low-quality coal tar and catalytic diesel in a mass ratio of 1:1.0, mix them, heat them to 60° C., and stir them at a medium speed for 30 minutes until they are fully mixed, to obtain a crude oil;

[0070] (2) Add 200 ppm of demulsifier to the above-mentioned crude oil, maintain the temperature at 60° C. and stir at medium speed for 20 min until fully mixed; continue to add 400 ppm of sedimentation agent, maintain the temperature at 60° C. and stir at high speed for 30 min until fully mixed, and let it stand for 24 hours;

[0071] (3) 95% of the crude oil in the upper layer is extracted and filtered through a 10 μm ceramic membrane filter to obtain the product.

[0072] Comparative Preparation Example 1

[0073] The coal tar hydrogenation pretreatment method described in this comparative preparation example comprises the following steps:

[0074] (1) Weighing high-temperature low-quality coal tar and catalytic diesel in a mass ratio of 1:0.7, mixing them, heating them to 60° C. and stirring them at a medium speed for 30 minutes until they are fully mixed, to obtain a crude oil;

[0075] (2) Add 200 ppm of sedimentation agent to the above-mentioned crude oil, maintain the temperature at 60° C. and stir at high speed for 30 min until fully mixed, and let it stand for 24 hours;

[0076] (3) 95% of the crude oil in the upper layer is extracted and filtered through a 10 μm ceramic membrane filter to obtain the product.

[0077] Comparative Preparation Example 2

[0078] The coal tar hydrogenation pretreatment method described in this comparative preparation example comprises the following steps:

[0079] (1) Weighing high-temperature low-quality coal tar and catalytic diesel in a mass ratio of 1:0.7, mixing them, heating them to 60° C. and stirring them at a medium speed for 30 minutes until they are fully mixed, to obtain a crude oil;

[0080] (2) Add 150 ppm of demulsifier to the above-mentioned crude oil, stir at medium speed for 20 min at 60° C. until fully mixed, and let stand for 24 hours;

[0081] (3) 95% of the crude oil in the upper layer is extracted and filtered through a 10 μm ceramic membrane filter to obtain the product.

[0082] The performance indicators of the pretreated high-temperature inferior coal tar obtained in the above preparation examples and comparative preparation examples before and after treatment were analyzed, and the results are shown in Table 1 below.

[0083] Table 1 Analysis of index properties of high temperature inferior coal tar before and after treatment

[0084]

[0085] It can be seen from the data in Table 1 that the use of the pretreatment method of the present invention to treat high-temperature low-quality coal tar can significantly reduce the residual carbon, ash, mechanical impurities, and asphaltene content therein, and the impurities of the high-temperature low-quality coal tar are effectively removed, thereby reducing the impact of these impurities on the catalyst, and providing a guarantee for the subsequent utilization of high-temperature low-quality coal tar. However, the removal rate of impurities in Comparative Examples 1 and 2 is significantly reduced, and the effective filtration cycle of the ceramic membrane is significantly shortened, which is not conducive to long-term operation and reduces production efficiency. In the method described in the present invention, after the high-temperature / low-quality coal tar is subjected to the above-mentioned pretreatment method, the whole fraction raw material can be introduced into the ebullating bed hydrogenation device for hydrogenation treatment to obtain hydrogenated coal tar.

[0086] Preparation Example 6-9

[0087] The following Preparation Examples 6-9 were respectively hydrogenated based on the whole fraction raw materials pretreated in the aforementioned Preparation Examples 1-4. The filtered whole fraction raw materials were respectively introduced into an ebullated bed hydrogenation device, the reaction pressure was controlled to be 13 MPa, the hydrogen-to-oil volume ratio was 400:1, the reaction temperature was 350°C, the hydrogenation reaction was carried out, and the hydrogenation products were collected.

[0088] Comparative Preparation Example 3-4

[0089] The following comparative preparation examples 3-4 are respectively based on the hydrogenation treatment of the whole fraction raw materials pretreated in the aforementioned comparative preparation examples 1-2, and the filtered whole fraction raw materials are respectively introduced into the ebullated bed hydrogenation device, the reaction pressure is controlled to be 13MPa, the hydrogen-oil volume ratio is 400:1, the reaction temperature is 350°C, the hydrogenation reaction is carried out, and the hydrogenation products are collected.

[0090] Table 2 below shows the pressure drop of the hydrogenation reactor in the Preparation Examples 6-9 and Comparative Preparation Examples 3-4.

[0091] Table 2 Hydrogenation reactor pressure drop

[0092]

[0093] It can be seen from Table 2 that after pretreatment of high-temperature low-quality coal tar, the rate of increase of reactor pressure drop is reduced and the operation cycle is extended. The reactor pressure drop of Comparative Examples 3 and 4 increases rapidly, which is not conducive to long-term operation of the device and is not suitable for hydroprocessing.

[0094] Example 1

[0095] Weigh 10 parts by weight of the hydrogenated coal tar obtained in Preparation Example 6 and 5 parts by weight of catalytic diesel, mix them, stir at medium speed for 30 minutes, continue to add 75 parts by weight of hydrogenated residue oil, heat to 30°C, and stir at medium speed for 30 minutes; continue to add 10 parts by weight of catalytic oil slurry, heat to 50°C, stir at medium speed for 30 minutes, and fully blend to obtain the required RMG180 low-sulfur heavy marine residual fuel oil.

[0096] Example 2

[0097] Weigh 15 parts by weight of the hydrogenated coal tar obtained in Preparation Example 6 and mix with 2 parts by weight of ethylene diesel, stir at medium speed for 30 minutes, continue to add 70 parts by weight of hydrogenated residue oil, heat to 40°C, and stir at medium speed for 30 minutes; continue to add 13 parts by weight of catalytic oil slurry, heat to 60°C, stir at medium speed for 30 minutes, and fully blend to obtain the required RMG180 low-sulfur heavy marine residual fuel oil.

[0098] Example 3

[0099] Weigh 15 parts by weight of the hydrogenated coal tar obtained in Preparation Example 6 and 5 parts by weight of catalytic diesel, mix them, stir at medium speed for 30 minutes, continue to add 65 parts by weight of hydrogenated residue oil, heat to 40°C, and stir at medium speed for 30 minutes; continue to add 15 parts by weight of catalytic oil slurry, heat to 60°C, stir at medium speed for 30 minutes, and fully blend to obtain the required RMG180 low-sulfur heavy marine residual fuel oil.

[0100] Example 4

[0101] Weigh 20 parts by weight of the hydrogenated coal tar obtained in Preparation Example 6 and 3 parts by weight of catalytic diesel, mix them, stir at medium speed for 30 minutes, continue to add 60 parts by weight of hydrogenated residue oil, heat to 40°C, and stir at medium speed for 30 minutes; continue to add 17 parts by weight of catalytic oil slurry, heat to 60°C, stir at medium speed for 30 minutes, and fully blend to obtain the required RMG180 low-sulfur heavy marine residual fuel oil.

[0102] Example 5

[0103] Weigh 5 parts by weight of the hydrogenated coal tar obtained in Preparation Example 6 and mix with 10 parts by weight of catalytic diesel, stir at medium speed for 30 minutes, continue to add 50 parts by weight of hydrogenated residue oil, heat to 40°C, and stir at medium speed for 30 minutes; continue to add 20 parts by weight of catalytic oil slurry, heat to 60°C, stir at medium speed for 30 minutes, and fully blend to obtain the required RMG180 low-sulfur heavy marine residual fuel oil.

[0104] Example 6

[0105] Weigh 25 parts by weight of the hydrogenated coal tar obtained in Preparation Example 6 and mix with 8 parts by weight of catalytic diesel, stir at medium speed for 30 minutes, continue to add 80 parts by weight of hydrogenated residue oil, heat to 40°C, and stir at medium speed for 30 minutes; continue to add 5 parts by weight of catalytic oil slurry, heat to 60°C, stir at medium speed for 30 minutes, and fully blend to obtain the required RMG180 low-sulfur heavy marine residual fuel oil.

[0106] Comparative Example 1

[0107] Weigh 15 parts by weight of the hydrogenated coal tar obtained in Preparation Example 6 and 15 parts by weight of catalytic diesel, mix them, stir at medium speed for 30 minutes, continue to add 55 parts by weight of hydrogenated residue oil, heat to 40°C, and stir at medium speed for 30 minutes; continue to add 15 parts by weight of catalytic oil slurry, heat to 60°C, stir at medium speed for 30 minutes, and fully blend to obtain the required RMG180 low-sulfur heavy marine residual fuel oil.

[0108] Comparative Example 2

[0109] Weigh 15 parts by weight of untreated high-temperature low-quality coal tar and 5 parts by weight of catalytic diesel, mix them, stir at medium speed for 30 minutes, continue to add 60 parts by weight of hydrogenated residue oil, heat to 40°C, and stir at medium speed for 30 minutes; continue to add 15 parts by weight of catalytic oil slurry, heat to 60°C, stir at medium speed for 30 minutes, and fully blend to obtain the required RMG180 low-sulfur heavy marine residual fuel oil.

[0110] In the above examples, the main performance test results of the selected raw oils such as hydrogenated residue oil, diesel, ethylene tar and slurry oil are shown in Table 3.

[0111] Table 3 Main performance test results of crude oil

[0112]

[0113] According to the current national standard GB / T 17411-2015 for marine fuel oil, the main technical index requirements and test results of the marine residual fuel oil obtained in the above Examples 1-4 and Comparative Examples 1-2 are shown in Table 4.

[0114] Table 4 Test results of low sulfur heavy marine fuel oil

[0115]

[0116] It can be seen from the data in Table 4 above that the kinematic viscosity, density, flash point, acid value, and aluminum-silicon content of the low-sulfur heavy marine fuel oil prepared by the present invention based on hydrogenated coal tar have reached the quality standards, especially the sulfur content is less than 0.4%, which is lower than the current standard of 0.5%, and meets the increasingly stringent environmental protection requirements. In the preparation process of low-sulfur heavy marine fuel oil, due to the addition of hydrogenated coal tar with abundant output, low price and low sulfur content, the blending ratio of low value-added product catalytic oil slurry can be correspondingly increased, which plays a role in reducing the sulfur content of the product, digesting the catalytic oil slurry, and reducing costs. It can be seen from the comparative effect that the density, viscosity, ash content, and calorific value of the untreated coal tar directly blended with marine fuel are all unqualified.

[0117] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for preparing hydrogenated coal tar, characterized in that: The steps include: (1) taking the coal tar to be processed and adding the diluent oil to mix to obtain the raw oil for standby use; (2) adding a demulsifier and a sedimentation agent to the crude oil in sequence, and heating the crude oil to 40-70° C. for treatment; (3) Extract 95% of the raw oil from the upper layer, filter it, and introduce the whole fraction into the hydrogenation unit for hydrogenation treatment to obtain; The mass ratio of the coal tar to the diluent oil is 1:0.1-1.0; The demulsifier comprises a mixture of alkylphenol formaldehyde resin polyoxypropylene polyoxyethylene ether and xylene in a mass ratio of 5%-15%:85%-95%; The amount of demulsifier added is 100-200ppm; The sedimentation agent comprises a mixture of fatty alcohol polyoxyethylene ether, polyacrylamide and glycerol in a mass ratio of 18%-24%: 65%-75%: 6%-10%; The added amount of the sedimentation agent is 100-400ppm.

2. The method for preparing hydrogenated coal tar according to claim 1, characterized in that: In the step (1): The diluent oil includes catalytic diesel.

3. The method for preparing hydrogenated coal tar according to claim 1 or 2, characterized in that: In the step (3), the filtration step is ceramic membrane filtration, and the effective filtration accuracy of the ceramic membrane tube is controlled to be 2-10 μm.

4. The method for preparing hydrogenated coal tar according to claim 1 or 2, characterized in that: In the step (3), the hydrogenation device is an ebullated bed hydrogenation device; The process parameters of the hydroprocessing step include: reaction pressure of 12-14 MPa, hydrogen-to-oil volume ratio of 350-450:1, and reaction temperature of 330-370°C.

5. The method for preparing hydrogenated coal tar according to claim 1 or 2, characterized in that: In the step (1), the coal tar includes high-temperature coal tar.

6. The method for preparing hydrogenated coal tar according to claim 1 or 2, characterized in that: In the step (1), the coal tar includes low-quality coal tar.

7. A method for preparing low-sulfur heavy marine fuel oil, characterized in that: The composition comprises the following components in parts by weight: 50-80 parts by weight of residual oil; 5-20 parts by weight of catalytic slurry; 5-25 parts by weight of hydrogenated coal tar; Diesel 2-10 parts by weight; The hydrogenated coal tar is prepared according to the method of claim 1.

8. The method for preparing low-sulfur heavy marine fuel oil according to claim 7, characterized in that: The residual oil includes hydrogenated residual oil; The diesel oil includes catalytic diesel oil, ethylene diesel oil, coking diesel oil or a mixture of the two or more thereof.

9. The method for preparing low-sulfur heavy marine fuel oil according to claim 7 or 8, characterized in that: The method comprises the steps of blending selected amounts of the residual oil, catalytic oil slurry, hydrogenated coal tar and diesel at 50-60°C.

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