Coal biofuel as well as preparation method and application thereof

Abstract

The embodiment of the invention relates to coal biofuel as well as a preparation method and application thereof. The coal biofuel comprises the following components in percentage by mass: 3%-8% of polyol heavy component treating fluid, 2%-5% of biodiesel treating fluid, 30%-45% of coal-based diesel oil, 25%-50% of petroleum distillate oil with the temperature of 180-300 DEG C, 5%-10% of coal-based diesel oil with the temperature of 180-300 DEG C and the balance of water. The mass ratio of the petroleum distillate oil at 180-360 DEG C is 12-20%; and the mass ratio of the high-boiling-point aromatic hydrocarbon solvent is 2-5%. According to the coal biofuel provided by the embodiment of the invention, the resource consumption of oil and gas can be reduced, the traditional energy structure is improved, the energy safety is improved, and the environmental pollution is reduced. Moreover, the coal biofuel is convenient to use, the key indexes of the coal biofuel are superior to the national standard of diesel oil, and the coal biofuel can completely replace the diesel oil.

Description

Technical Field

[0001] The present invention relates to the technical field of fuels, and particularly to a coal-based biofuel, a preparation method thereof, and an application thereof. Background Art

[0002] With the improvement of the people's economic level, the demand for automobiles is increasing. As a result, the consumption of gasoline and diesel has been steadily growing, and the external dependence on crude oil has climbed to nearly 80% in recent years. Developing multiple energy sources and reducing the dependence on crude oil is an urgent task for enhancing China's energy security.

[0003] At present, although there are some products that can replace gasoline, compression-ignition internal combustion engines still mainly use pure diesel. Heavy-duty diesel trucks and large ships are "fuel guzzlers" that consume a large amount of diesel. Their exhaust emissions are dozens of times that of gasoline vehicles, causing serious environmental pollution.

[0004] China is a country rich in coal, poor in oil, and short of gas. As coal is the main energy source in China, it is urgent to improve the comprehensive utilization efficiency of coal as a chemical raw material and promote the high-end, diversified, and low-carbon development of the coal chemical industry. This requires strengthening coal industry scientific and technological innovation, accelerating core technology research, and actively developing the research and development of coal-based special fuels, coal-based biodegradable materials, etc. Summary of the Invention

[0005] The object of the present invention is to provide a coal-based biofuel, a preparation method thereof, and an application thereof to address the deficiencies of the existing technology.

[0006] To achieve the above object, in a first aspect, the present invention provides a coal-based biofuel, which includes: a polyol heavy component treatment liquid with a mass ratio of 3% - 8%, a biodiesel treatment liquid with a mass ratio of 2% - 5%, a coal-based diesel with a mass ratio of 30% - 45%, a petroleum fraction oil at 180°C - 300°C with a mass ratio of 25% - 50%, a petroleum fraction oil at 180°C - 360°C with a mass ratio of 12% - 20%, and a high-boiling aromatic solvent with a mass ratio of 2% - 5%.

[0007] Preferably, the coal-based biofuel includes: a polyol heavy component treatment liquid with a mass ratio of 3%, a biodiesel treatment liquid with a mass ratio of 2%, a coal-based diesel with a mass ratio of 33%, a petroleum fraction oil at 180°C - 300°C with a mass ratio of 45%, a petroleum fraction oil at 180°C - 360°C with a mass ratio of 14.5%, and a high-boiling aromatic solvent with a mass ratio of 2.5%.

[0008] Preferably, the coal-based biofuel further includes: an antioxidant; the mass ratio of the antioxidant in the coal-based biofuel is: 0.02% - 0.05%.

[0009] Preferably, the antioxidant includes one or more of benzotriazole derivatives, 2,6-di-tert-butyl-4-methylphenol, and dialkyldithiophosphoric acid.

[0010] In a second aspect, the present invention provides a preparation method of the coal-based biofuel according to any one of the above first aspects, and the preparation method includes:

[0011] Rectifying and cutting the polyol to obtain a polyol heavy fraction precursor solution;

[0012] Adding a first pH adjusting substance with a first mass ratio to the polyol heavy fraction precursor solution, stirring for a first duration at a first temperature, then keeping it at a constant temperature for a second duration at a second temperature, taking the upper transparent liquid for filtration to obtain a polyol heavy fraction treatment solution;

[0013] Adding a second pH adjusting substance with a second mass ratio to the biodiesel, stirring for a third duration at a third temperature, then keeping it at a constant temperature for a fourth duration at a fourth temperature, taking the upper transparent liquid for filtration to obtain a biodiesel treatment solution;

[0014] Under normal temperature and pressure, sequentially adding petroleum fraction oil at 180°C - 300°C, high-boiling aromatic hydrocarbons, and petroleum fraction oil at 180°C - 360°C to a reaction kettle for stirring for a fifth duration, then adding the polyol heavy fraction treatment solution and the biodiesel treatment solution for stirring for a sixth duration, then adding coal-based diesel for stirring for a seventh duration, and finally adding an antioxidant for stirring for an eighth duration, and then standing for a ninth duration to obtain the coal-based biofuel.

[0015] Preferably, the first mass ratio is 2% - 5%, and the first pH adjusting substance includes one or both of potassium hydroxide and sodium hydroxide.

[0016] Preferably, the first temperature is 60°C - 80°C, the first duration is 1 - 3 hours, the second temperature is 35°C - 45°C, and the second duration is 16 - 24 hours.

[0017] Preferably, the second mass ratio is 0.3% - 0.8%, and the second pH adjusting substance includes one or both of potassium hydroxide and sodium hydroxide.

[0018] Preferably, the third temperature is 50°C - 60°C, the third duration is 1 - 3 hours, the fourth temperature is 35°C - 50°C, and the fourth duration is 3 - 8 hours.

[0019] In a third aspect, the present invention provides a use of the coal-based biofuel according to any one of the above first aspects or the coal-based biofuel prepared by the preparation method according to any one of the above second aspects, and the coal-based biofuel is applied to a compression ignition internal combustion engine.

[0020] The coal-based biofuel provided by the embodiments of the present invention. Among them, the polyol heavy component treatment liquid and the biodiesel treatment liquid can be prepared using biomass materials, meeting the conditions of being renewable, reducing the consumption of oil and gas resources, improving the traditional energy structure, and enhancing energy security. The raw material of coal-based diesel comes from coal chemical products, and the number of carbon atoms per unit mass is less than that of petrochemical products, reducing carbon emissions and thus reducing environmental pollution. Moreover, through reasonable formulation design, the key indicators of this coal-based biofuel are superior to those of diesel meeting national standards, having good fuel economy, reducing fuel consumption per unit mileage, reducing tail gas emissions, being able to completely replace diesel, and being mutually compatible with diesel meeting national standards without any modification to the vehicle. In addition, the raw materials of this coal-based biofuel are mostly coal chemical products, which are economical and affordable. There are numerous coal chemical products that can be selected as raw materials, effectively controlling the ex-factory cost and having better economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a flowchart of the preparation method of the coal-based biofuel provided by the embodiments of the present invention;

[0022] Figure 2-a It is one of the three-way catalytic sensor diagrams after a vehicle is filled with the coal-based biofuel provided by Embodiment 4 of the present invention;

[0023] Figure 2-b It is a three-way catalytic converter diagram after a vehicle is filled with the coal-based biofuel provided by Embodiment 4 of the present invention;

[0024] Figure 2-c It is a urea sensor diagram after a vehicle is filled with the coal-based biofuel provided by Embodiment 4 of the present invention;

[0025] Figure 3-a It is a three-way catalytic sensor diagram after a vehicle is filled with the coal-based biofuel provided by traditional diesel;

[0026] Figure 3-b It is a three-way catalytic converter diagram after a vehicle is filled with the coal-based biofuel provided by traditional diesel;

[0027] Figure 3-c It is a urea sensor diagram after a vehicle is filled with the coal-based biofuel provided by traditional diesel. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0029] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0030] An embodiment of the present invention provides a coal-based biofuel, which specifically may include: a polyol heavy component treatment liquid with a mass ratio of 3% - 8%, a biodiesel treatment liquid with a mass ratio of 2% - 5%, a coal-based diesel with a mass ratio of 30% - 45%, a petroleum fraction oil at 180°C - 300°C with a mass ratio of 25% - 50%, a petroleum fraction oil at 180°C - 360°C with a mass ratio of 12% - 20%, and a high-boiling aromatic solvent with a mass ratio of 2% - 5%. Preferably, the polyol heavy component treatment liquid has a mass ratio of 3%, the biodiesel treatment liquid has a mass ratio of 2%, the coal-based diesel has a mass ratio of 33%, the petroleum fraction oil at 180°C - 300°C has a mass ratio of 45%, the petroleum fraction oil at 180°C - 360°C has a mass ratio of 14.5%, and the high-boiling aromatic solvent has a mass ratio of 2.5%.

[0031] The polyol heavy component treatment liquid and the biodiesel treatment liquid have a relatively high cetane number, making the coal-based biofuel have good ignition performance, short ignition delay period, uniform combustion, and smooth engine start. Both belong to biomass materials and can be prepared from biomass materials, meeting the renewable conditions, reducing the dependence on petrochemical energy, improving the traditional energy structure, and enhancing energy security. And the biodiesel treatment liquid does not contain sulfur, which can reduce environmental pollution.

[0032] The raw material of the coal-based diesel comes from coal chemical products, and the Fischer-Tropsch process runs through the entire distillation range during the preparation process, making the coal-based diesel have low sulfur and low nitrogen, and the number of carbon atoms per unit mass is less than that of petrochemical products, reducing carbon emissions and thus reducing environmental pollution.

[0033] In this coal-based biofuel, the mass ratio of the coal-based diesel exceeds 33% and the mass ratio of the biomass material exceeds 5%, which meets the requirements of new energy.

[0034] The petroleum fraction oil at 180°C - 300°C can improve the cold start performance of the engine.

[0035] The petroleum fraction oil at 180°C - 360°C has the advantages of wide distillation range and strong combustion stability, making the coal-based biofuel have low fuel consumption.

[0036] The high-boiling aromatic solvent only needs to meet the standard of "GB / T 29497-2017 High-Boiling Aromatic Solvent". Its solubility is particularly strong, which can reduce the viscosity and freezing point of the product, and can also slow down the oxidation of the product and increase the oxidation stability of the product.

[0037] In a preferred embodiment, to slow down the oxidation of the coal-based biofuel and increase its oxidation stability, the coal-based biofuel may further include an antioxidant, and the mass ratio of the antioxidant in the coal-based biofuel may be: 0.02% - 0.05%.

[0038] Specifically, the antioxidant may include one or more of benzotriazole derivatives, 2,6-di-tert-butyl-4-methylphenol, and dialkyldithiophosphoric acid.

[0039] The coal-based biofuel provided by the embodiments of the present invention, wherein the polyol heavy fraction treatment liquid can be prepared using biomass materials, has renewable conditions, can reduce the resource consumption of oil and gas, improve the traditional energy structure, and enhance energy security. The carbon atoms per unit mass of coal-based diesel from coal chemical products are less than those of petrochemical products, reducing carbon emissions and thus reducing environmental pollution. Moreover, through reasonable formulation design, the key indicators of this coal-based biofuel are superior to those of national standard diesel, with good fuel economy, reducing fuel consumption per unit mileage, reducing tail gas emissions, being able to completely replace diesel, and being compatible with national standard diesel for use without any modification to the vehicle. Additionally, the raw materials of this coal-based biofuel are mostly coal chemical products, which are economical and practical. There are numerous coal chemical products that can be selected as raw materials, effectively controlling the ex-factory cost and having better economic benefits.

[0040] The embodiments of the present invention also provide a preparation method of a coal-based biofuel, and the process is as Figure 1 shown, including the following steps:

[0041] Step 110: Rectify and cut the polyol to obtain a polyol heavy fraction precursor solution;

[0042] Specifically, the polyol heavy fraction treatment liquid utilizes the difference in the volatility of each component of the polyol heavy fraction. Through multiple gasifications and condensations, each component is separated one by one, that is, obtained by rectifying and cutting. The rectifying and cutting can be specifically implemented using a rectification tower well-known in the art. At the top of the rectification tower, the light components are more volatile and will be preferentially separated. For example, in this application, the heavy fraction after 150°C is required. When the bottom temperature of the rectification tower reaches 180°C, the top temperature can reach 150°C. At this time, the components with a temperature lower than 150°C in the gas phase are gasified and separated, and the remaining components in the rectification tower are the polyol heavy fraction precursor solution.

[0043] Step 120: Add a first pH adjusting substance with a first mass ratio to the polyol heavy fraction precursor solution, stir for a first duration at a first temperature, then keep it at a constant temperature and stand for a second duration at a second temperature, and filter the upper transparent liquid to obtain a polyol heavy fraction treatment liquid;

[0044] Specifically, the first mass ratio can be 2% - 5%. The first pH adjustment substance includes one or both of potassium hydroxide and sodium hydroxide. It should be noted that all potassium hydroxide and sodium hydroxide involved in this application are powders. Since the acidity of polyols is relatively high, in order to prevent the coal-based biofuel from acidifying and deteriorating during transportation and storage and from corroding the parts of the internal combustion engine during use, it is necessary to adjust its pH value. In a specific example, the pH value can be 6 - 8, preferably 6.5. The first temperature can be 60°C - 80°C, preferably 60°C, the first duration can be 1 hour - 3 hours, preferably 1 hour, the second temperature is 35°C - 45°C, preferably 40°C, and the second duration is 16 hours - 24 hours, preferably 24 hours.

[0045] The static settlement is mainly based on the density difference, so that the salts and water formed by the first pH adjustment substance and the acid slowly settle to the bottom of the reaction vessel, facilitating subsequent separation.

[0046] Filtration can specifically be carried out using a filter cloth with 10,000 meshes or more. Filtration is mainly to remove the salts that have not completely settled after static settlement, ensuring the purity of the product and improving its oxidation stability.

[0047] Step 130: Add the second pH adjustment substance with the second mass ratio to the biodiesel, stir for the third duration at the third temperature, then keep it at a constant temperature for the fourth duration at the fourth temperature, and take the upper transparent liquid for filtration to obtain the biodiesel treatment liquid;

[0048] Specifically, the second mass ratio can be 0.3% - 0.8%. The second pH adjustment substance includes one or both of potassium hydroxide and sodium hydroxide. The adjusted pH value can be 6 - 8, preferably 6.5. The third temperature can be 50°C - 60°C, preferably 50°C, the third duration is 1 hour - 3 hours, preferably 1 hour, the fourth temperature can be 35°C - 50°C, preferably 40°C, and the fourth duration can be 3 hours - 8 hours, preferably 4 hours.

[0049] Filtration can specifically be carried out using a filter cloth with 10,000 meshes or more. The functions of static settlement and filtration are the same as those in step 120.

[0050] Step 140: Under normal temperature and pressure, add petroleum distillate oil at 180°C - 300°C, high-boiling aromatics, and petroleum distillate oil at 180°C - 360°C to the reaction kettle in sequence and stir for the fifth duration, then add the polyol heavy fraction treatment liquid and the biodiesel treatment liquid and stir for the sixth duration, then add coal-based diesel and stir for the seventh duration, and finally add an antioxidant and stir for the eighth duration, and then let it stand for the ninth duration to obtain the coal-based biofuel.

[0051] Specifically, the mass ratio of the antioxidant in the coal-based biofuel can be: 0.02%-0.05%. The antioxidant can specifically include one or several of benzotriazole derivatives, 2,6-di-tert-butyl-4-methylphenol, and dialkyldithiophosphoric acid.

[0052] The fifth duration can be 10 min - 15 min, preferably 10 min. The sixth duration can be 10 min - 15 min, preferably 10 min. The seventh duration can be 10 min - 15 min, preferably 10 min. The eighth duration can be 15 min - 20 min, preferably 15 min. The ninth duration can be 36 hours - 60 hours, preferably 48 hours.

[0053] The preparation method of the coal-based biofuel provided by the embodiment of the present invention obtains a polyol heavy fraction treatment liquid by rectifying and cutting the polyol, obtains a biodiesel treatment liquid by adjusting the pH value of the biodiesel, standing, and filtering, and then sequentially adds them into a reaction kettle and stirs to obtain the coal-based biofuel. The preparation process is simple and easy to operate. There is only a physical reaction and no chemical reaction throughout the process, making the coal-based biofuel easier to transport and store. It realizes that the key indicators of the coal-based biofuel are better than those of national standard diesel, can completely replace diesel, and can also be used compatibly with national standard diesel, being safe and pollution-free.

[0054] The coal-based biofuel provided by the embodiment of the present invention can be applied to machines with compression-ignition internal combustion engines such as automobiles, ships, construction machinery, and motorcycles.

[0055] To better understand the technical solution provided by the present invention, the following uses multiple specific examples to separately illustrate the specific process of preparing the coal-based biofuel by applying the method provided by the above embodiments of the present invention, as well as the properties of the prepared coal-based biofuel. It should be noted that the rectifying and cutting process involved in the following examples is carried out under normal pressure conditions.

[0056] Example 1

[0057] First step, rectify and cut the polyol. When the bottom temperature of the rectifying column reaches 180°C, collect the polyol heavy fraction precursor solution.

[0058] Second step, add potassium hydroxide powder with a mass ratio of 4% to the polyol heavy fraction precursor solution to make the pH of the polyol heavy fraction precursor solution 6.5. Stir at 80°C for 1 hour, then keep it at a constant temperature of 35°C and stand for 24 hours. Take the upper transparent liquid and filter it with a filter cloth of 15,000 meshes to obtain the polyol heavy fraction treatment liquid.

[0059] Step 3: Add potassium hydroxide powder with a mass ratio of 0.4% to the biodiesel to make the pH value of the biodiesel reach 7. Stir for 1 hour at 60 °C, then keep it at a constant temperature of 35 °C and let it stand still for 8 hours. Take the upper transparent liquid and filter it with a filter cloth of 12,000 mesh to obtain the biodiesel treatment liquid.

[0060] Step 4: Under normal temperature and pressure, add petroleum fraction oil at 180 °C - 300 °C with a mass ratio of 28%, high-boiling aromatic hydrocarbons with a mass ratio of 5%, and petroleum fraction oil at 180 °C - 360 °C with a mass ratio of 20% to the reaction kettle in sequence and stir for 12 min. Then add the polyol heavy component treatment liquid with a mass ratio of 8% and the biodiesel treatment liquid with a mass ratio of 3% and stir for 12 min. After that, add coal-based diesel with a mass ratio of 36% and stir for 12 min. Finally, add 2,6-di-tert-butyl-para-cresol with a mass ratio of 0.05% and stir for 18 min, then let it stand still for 36 hours to obtain the coal-based biofuel.

[0061] It should be noted in this step that the mass of various substances added to the reaction kettle is calculated according to the total mass of the coal-based biofuel to be finally obtained and the percentages of each substance. For example, to prepare 100 g of coal-based biofuel, 28 g of petroleum fraction oil at 180 °C - 300 °C, 5 g of high-boiling aromatic hydrocarbons, 20 g of petroleum fraction oil at 180 °C - 360 °C, 8 g of polyol heavy component treatment liquid, 3 g of biodiesel treatment liquid, 36 g of coal-based diesel, and 0.05 g of 2,6-di-tert-butyl-para-cresol are required. In addition, although the sum of the masses of various substances in the coal-based biofuel is greater than 100 g, which is 100.05 g in this example, since the addition amount of the antioxidant is relatively small, it can be ignored. The principle of this step in the following examples is the same as that in this example, so it will not be elaborated here.

[0062] Example 2

[0063] Step 1: Carry out rectification cutting on the polyol. When the bottom temperature of the rectification tower reaches 180 °C, collect the polyol heavy component precursor solution.

[0064] Step 2: Add sodium hydroxide powder with a mass ratio of 5% to the polyol heavy component precursor solution to make the pH of the polyol heavy component precursor solution 8. Stir for 2 hours at 70 °C, then keep it at a constant temperature of 45 °C and let it stand still for 16 hours. Take the upper transparent liquid and filter it with a filter cloth of 12,000 mesh to obtain the polyol heavy component treatment liquid.

[0065] In the third step, add sodium hydroxide powder with a mass ratio of 0.5% to the biodiesel to make the pH value of the biodiesel reach 7.5. Stir for 2 hours at 55°C, then keep it at a constant temperature of 50°C and let it stand for 3 hours. Take the upper transparent liquid and filter it using a filter cloth with a mesh size of 11,000 to obtain the biodiesel treatment liquid.

[0066] In the fourth step, under normal temperature and pressure, add petroleum fraction oil with a mass ratio of 25% at 180°C - 300°C, high-boiling aromatic hydrocarbons with a mass ratio of 4%, and petroleum fraction oil with a mass ratio of 15% at 180°C - 360°C to the reaction kettle in sequence and stir for 15 minutes. Then add the polyol heavy fraction treatment liquid with a mass ratio of 6% and the biodiesel treatment liquid with a mass ratio of 5% and stir for 15 minutes. After that, add coal-based diesel with a mass ratio of 45% and stir for 15 minutes. Finally, add dialkyldithiophosphate with a mass ratio of 0.04% and stir for 20 minutes, then let it stand for 60 hours to obtain the coal-based biofuel.

[0067] Example 3

[0068] In the first step, rectify and cut the polyol. When the bottom temperature of the rectification tower reaches 180°C, collect the polyol heavy fraction precursor solution.

[0069] In the second step, add sodium hydroxide powder with a mass ratio of 2.5% to the polyol heavy fraction precursor solution to make the pH of the polyol heavy fraction precursor solution 7.5. Stir for 3 hours at 65°C, then keep it at a constant temperature of 38°C and let it stand for 20 hours. Take the upper transparent liquid and filter it using a filter cloth with a mesh size of 11,000 to obtain the polyol heavy fraction treatment liquid.

[0070] In the third step, add sodium hydroxide powder with a mass ratio of 0.6% to the biodiesel to make the pH value of the biodiesel reach 7.5. Stir for 3 hours at 55°C, then keep it at a constant temperature of 45°C and let it stand for 5 hours. Take the upper transparent liquid and filter it using a filter cloth with a mesh size of 10,000 to obtain the biodiesel treatment liquid.

[0071] In the fourth step, under normal temperature and pressure, add petroleum fraction oil with a mass ratio of 50% at 180°C - 300°C, high-boiling aromatic hydrocarbons with a mass ratio of 2%, and petroleum fraction oil with a mass ratio of 12% at 180°C - 360°C to the reaction kettle in sequence and stir for 13 minutes. Then add the polyol heavy fraction treatment liquid with a mass ratio of 4% and the biodiesel treatment liquid with a mass ratio of 2% and stir for 15 minutes. After that, add coal-based diesel with a mass ratio of 30% and stir for 13 minutes. Finally, add benzotriazole derivative with a mass ratio of 0.02% and stir for 18 minutes, then let it stand for 50 hours to obtain the coal-based biofuel.

[0072] Example 4

[0073] First step, subject the polyol to rectification cutting. When the bottom temperature of the rectification column reaches 180 °C, collect the polyol heavy component precursor solution.

[0074] Second step, add potassium hydroxide powder with a mass ratio of 3% to the polyol heavy component precursor solution to make the pH of the polyol heavy component precursor solution 6.5. Stir at 60 °C for 1 hour, then keep it at a constant temperature of 40 °C and let it stand for 24 hours. Take the upper clear liquid and filter it through a filter cloth with a mesh size of 10,000 to obtain the polyol heavy component treatment liquid.

[0075] Third step, add potassium hydroxide powder with a mass ratio of 0.3% to the biodiesel to make the pH value of the biodiesel reach 6.5. Stir at 50 °C for 1 hour, then keep it at a constant temperature of 40 °C and let it stand for 4 hours. Take the upper clear liquid and filter it through a filter cloth with a mesh size of 11,000 to obtain the biodiesel treatment liquid.

[0076] Fourth step, at normal temperature and pressure, sequentially add petroleum fraction oil with a mass ratio of 45% at 180 °C - 300 °C, high-boiling aromatic hydrocarbons with a mass ratio of 2.5%, and petroleum fraction oil with a mass ratio of 14.5% at 180 °C - 360 °C to the reaction kettle and stir for 10 min. Then add the polyol heavy component treatment liquid with a mass ratio of 3% and the biodiesel treatment liquid with a mass ratio of 2% and stir for 10 min. After that, add coal-based diesel with a mass ratio of 33% and stir for 10 min. Finally, add benzotriazole derivative with a mass ratio of 0.02% and stir for 15 min, and then let it stand for 48 hours to obtain the coal-based biofuel.

[0077] First, test the coal-based biofuel prepared in Example 4 according to the national standard of "Automotive Diesel" GB 19147-2016. The test results are shown in Table 1.

[0078] Table 1 shows the test results of the coal-based biofuel prepared in Example 4 of the present invention.

[0079]

[0080] Table 1

[0081] As can be seen from Table 1, the coal-based biofuel prepared in Example 4 of the present invention meets the national standard for automotive diesel, and the sulfur content meets the requirements, which can reduce environmental pollution.

[0082] Then, the coal-based biofuels prepared in Examples 1-4 of the present invention, conventional diesel, and the coal-based biofuels prepared in Examples 1-4 and conventional diesel (national standard diesel) were mixed at various mixing ratios and then their application performance was tested using a pickup truck. The mixing ratios were all between Example 4 and conventional diesel, with mixing ratio 1 being 2:8, mixing ratio 2 being 4:6, mixing ratio 3 being 6:4, and mixing ratio 4 being 8:2.

[0083] Table 2 shows the economic test results of the coal-based biofuel, traditional diesel, and the mixture of coal-based biofuel and traditional diesel prepared in Examples 1-4 of the present application.

[0084]

[0085] Table 2

[0086] The difference between the product's road test mileage and that of conventional diesel fuel is due to repeated verification based on the data, even though the test route remains the same. Furthermore, the test route is adjusted after blending. This fuel mileage adjustment ensures the accuracy of fuel consumption throughout the test.

[0087] Average fuel consumption is the total fuel filled divided by the total fuel mileage. Fuel consumption difference is the difference between the average fuel consumption of conventional diesel and the average fuel consumption of Examples 1-4 and blend ratios 1-4. Fuel consumption ratio is the ratio of the average fuel consumption of Examples 1-4 and blend ratios 1-4 to the average fuel consumption of conventional diesel.

[0088] As shown in Table 2, the coal-based biofuel prepared by the present invention has lower average fuel consumption than traditional diesel. The coal-based biofuel of Example 4 of the present invention can save 6.87% of fuel, which is very economical.

[0089] Table 3 shows the power performance test results of the coal-based biofuel, traditional diesel, and a mixture of the coal-based biofuel and traditional diesel prepared in Example 4 of the present invention after being added to a vehicle.

[0090]

[0091]

[0092] Table 3

[0093] Among them, it can be seen from Table 3 that although the four average acceleration times of the coal-based biofuel of the present application are slightly higher than those of traditional diesel, that is, the power performance is 1% lower than that of traditional diesel, after being mixed with traditional diesel, the acceleration performance is better than that of traditional diesel, indicating that the use of coal-based biofuel will not affect the power of the vehicle.

[0094] Table 4 shows the emission test results of the coal-based biofuels prepared in Examples 1-4 of the present invention, traditional diesel, and the mixture of the coal-based biofuels and traditional diesel.

[0095]

[0096] Table 4

[0097] Among them, for the smoke density index: the degree of light blockage by the exhaust gas is measured by a smoke meter and expressed as a percentage (%), which reflects the emission of high-concentration particulate matter. 100% is the theoretical limit value, indicating that the light is completely blocked (rarely seen in practice), and 80% is a necessary item for annual vehicle inspection. In this application, the emission performance of the vehicle is tested by taking the average value of four tests.

[0098] As can be seen from Table 4, the smoke density and the content of nitrogen oxides in the vehicle exhaust after filling with the coal-based biofuel are much lower than those of traditional diesel. Especially for the coal-based biofuel in Example 4, the average value of the 100% point smoke density does not exceed 50% of traditional diesel, indicating that the coal-based biofuel of the present invention reduces carbon emissions and can reduce environmental pollution.

[0099] In summary, the coal-based biofuel of the embodiments of the present invention has advantages in terms of power performance, economy, and emission performance whether used alone or in combination with traditional diesel, and it is an environmental-friendly fuel that can completely replace traditional diesel.

[0100] Combined with Figures 2-a to 3-c It can be seen that after the vehicle travels 3000 kilometers after filling with the coal-based biofuel prepared in Example 4 of the present invention, observed by an endoscope, the effects on the three-way catalyst and urea sensor (such as corrosion, soot, and particulate matter, etc.) are not significantly different from those of traditional diesel, indicating that the coal-based biofuel of this application can replace traditional diesel.

[0101] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A coal-based biofuel, characterized in that, The coal-based biofuel includes: a polyol recombination component treatment liquid with a mass ratio of 3% - 8%, a biodiesel treatment liquid with a mass ratio of 2% - 5%, a coal-based diesel with a mass ratio of 30% - 45%, a petroleum fraction oil at 180°C - 300°C with a mass ratio of 25% - 50%, a petroleum fraction oil at 180°C - 360°C with a mass ratio of 12% - 20%, and a high-boiling aromatic solvent with a mass ratio of 2% - 5%.

2. The coal-based biofuel according to claim 1, characterized in that, The coal-based biofuel includes: a polyol recombination component treatment liquid with a mass ratio of 3%, a biodiesel treatment liquid with a mass ratio of 2%, a coal-based diesel with a mass ratio of 33%, a petroleum fraction oil at 180°C - 300°C with a mass ratio of 45%, a petroleum fraction oil at 180°C - 360°C with a mass ratio of 14.5%, and a high-boiling aromatic solvent with a mass ratio of 2.5%.

3. The coal-based biofuel according to claim 1, characterized in that, The coal-based biofuel further includes: an antioxidant; the mass ratio of the antioxidant in the coal-based biofuel is 0.02% - 0.05%.

4. The coal-based biofuel according to claim 1, wherein The antioxidant includes: one or several of benzotriazole derivatives, 2,6-di-tert-butyl-4-methylphenol, and dialkyldithiophosphoric acid.

5. The preparation method of the coal-based biofuel according to any one of claims 1-4, characterized in that, The preparation method includes: Performing rectification cutting on the polyol to obtain a polyol recombination component precursor solution; Adding a first pH adjustment substance with a first mass ratio to the polyol recombination component precursor solution, stirring for a first duration at a first temperature, then maintaining a constant temperature and standing for a second duration at a second temperature, and filtering the upper transparent liquid to obtain the polyol recombination component treatment liquid; Adding a second pH adjustment substance with a second mass ratio to the biodiesel, stirring for a third duration at a third temperature, then maintaining a constant temperature and standing for a fourth duration at a fourth temperature, and filtering the upper transparent liquid to obtain the biodiesel treatment liquid; Under normal temperature and pressure, sequentially adding a petroleum fraction oil at 180°C - 300°C, a high-boiling aromatic hydrocarbon, and a petroleum fraction oil at 180°C - 360°C to a reaction kettle and stirring for a fifth duration, then adding the polyol recombination component treatment liquid and the biodiesel treatment liquid and stirring for a sixth duration, then adding the coal-based diesel and stirring for a seventh duration, and finally adding the antioxidant and stirring for an eighth duration, and then standing for a ninth duration to obtain the coal-based biofuel.

6. The preparation method according to claim 5, characterized in that, The first mass ratio is 2% - 5%, and the first pH adjustment substance includes one or both of potassium hydroxide and sodium hydroxide.

7. The preparation method according to claim 5, characterized in that, The first temperature is 60°C - 80°C, the first duration is 1 hour - 3 hours, the second temperature is 35°C - 45°C, and the second duration is 16 hours - 24 hours.

8. The preparation method according to claim 5, characterized in that, The second mass ratio is 0.3% - 0.8%, and the second pH adjustment substance includes one or both of potassium hydroxide and sodium hydroxide.

9. The preparation method according to claim 5, characterized in that, The third temperature is 50°C - 60°C, the third duration is 1 hour - 3 hours, the fourth temperature is 35°C - 50°C, and the fourth duration is 3 hours - 8 hours.

10. Use of the coal-based biofuel according to any one of claims 1-4 above or the coal-based biofuel prepared by the preparation method according to any one of claims 5-9 above, characterized in that, The coal-based biofuel is applied to a compression-ignition internal combustion engine.

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