Safe fuel oil and preparation method thereof

Abstract

The invention relates to the technical field of fuel oil, and discloses safe fuel oil which is emulsified fuel oil and comprises the following components in percentage by mass: 70-80% of basic fuel oil including light diesel oil, biodiesel, ethylene glycol, high alcohol or a mixture thereof; 15%-25% of water which is deionized water or softened water; the emulsifying agent comprises an oil-soluble emulsifying agent and a water-soluble emulsifying agent, the oil-soluble emulsifying agent is Span 80, and the water-soluble emulsifying agent is Tween 80; and 0.5%-1% of a stabilizer. By optimizing the emulsifier formula and adding the modified zeolite powder, the stability of the emulsion is remarkably improved, particularly, the storage period of the emulsion can reach more than two years, and the emulsion can be kept stable without layering or precipitation at different environment temperatures; the long-term storage property of the fuel oil and the requirement on the emulsification stability in the transportation process are greatly improved, the maintenance and replacement frequency of the emulsifier in the storage process is reduced, and the maintenance cost of a user is saved.

Description

Technical Field

[0001] The invention relates to the technical field of fuel oil, in particular to safe fuel oil and a preparation method thereof. Background Art

[0002] With the continuous increase in global energy consumption and increasingly stringent environmental regulations, the application areas of fuel oil have gradually expanded and are widely used in industrial equipment, transportation, power generation and other fields. Traditional fuel oil, especially diesel fuel, has always been an important source of energy due to its excellent combustion performance and high energy efficiency. However, with the improvement of environmental protection requirements and the concern about climate change, the use of traditional fuel oil faces more and more challenges. Especially in the context of high emissions and high pollution, how to develop safe fuel oil that can maintain high efficiency and meet the requirements of low emissions and low pollution has become a technical problem that needs to be solved urgently.

[0003] In the prior art, many studies have been devoted to improving the performance of fuel oil, such as improving combustion efficiency and reducing emissions by adding emulsifiers, water-based emulsifiers, etc., while reducing the toxicity and pollution of the fuel. However, although these technologies have achieved some results to a certain extent, there are still many problems. For example, common emulsified fuels are prone to stratification or precipitation during storage, which affects their emulsification stability and leads to incomplete combustion during use. In addition, existing emulsified fuels often cannot maintain good starting performance in low temperature environments, and have poor oxidation resistance, and are prone to oxidation and deterioration during storage, which not only affects the service life of the fuel, but also increases the frequency and cost of equipment maintenance.

[0004] However, the emulsified fuel in the prior art still faces an important problem, that is, the stability of the fuel emulsion is poor, especially the poor stability under long-term storage and low-temperature environment, which is prone to stratification and precipitation, resulting in reduced combustion efficiency and increased emissions. This problem limits the use of fuel oil in high and low temperature environments, and it is difficult to meet the use requirements under long-term storage and harsh climatic conditions. Therefore, how to improve the stability of emulsified fuel, extend the storage period, and ensure that it has good starting performance in low-temperature environments has become a technical problem that needs to be solved urgently, and is also a problem proposed and solved by the present invention. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a safe fuel oil and a preparation method, which solves the problem that the fuel emulsion has poor stability, especially poor stability under long-term storage and low-temperature environment, and is prone to stratification and precipitation, resulting in reduced combustion efficiency and increased emissions.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: a safe fuel oil, comprising:

[0007] The fuel oil is an emulsified fuel oil, which comprises the following components by mass percentage:

[0008] 70% to 80% of base fuel oil, including light diesel, biodiesel, ethylene glycol, high alcohol or their mixtures;

[0009] Water 15% to 25%, deionized water or softened water;

[0010] 2% to 4% of an emulsifier, including an oil-soluble emulsifier and a water-soluble emulsifier, wherein the oil-soluble emulsifier is Span 80 and the water-soluble emulsifier is Tween 80;

[0011] Stabilizer 0.5% to 1%, which is polyvinyl alcohol or xanthan gum;

[0012] Explosion-proof agent: 0.3% to 0.5%, which is nano silicon dioxide or nano aluminum oxide;

[0013] Antioxidant 0.2% to 0.3%, 2,6-di-tert-butyl-p-cresol;

[0014] Antistatic agent 0.1% to 0.2%, which is a quaternary ammonium salt compound;

[0015] The combustion accelerator is 0.1% to 0.2%, which is potassium nitrate or low concentration hydrogen peroxide.

[0016] Preferably, the HLB value of the emulsifier is 10-12, and is obtained by compounding Span 80 and Tween 80 in a mass ratio of 3:7.

[0017] Preferably, the base fuel oil is prepared by mixing light diesel and biodiesel in a mass ratio of 9:1.

[0018] Preferably, the particle size of the explosion-proof agent is 10 to 15 nanometers, and the specific surface area is greater than 200 m 2 / g, uniformly dispersed in the emulsion by ultrasonic dispersion technology.

[0019] A method for preparing safe fuel oil comprises the following steps:

[0020] Step 1: Pretreatment of base fuel oil: filter and remove impurities from the base fuel oil and heat it to 50-60°C;

[0021] Step 2, preparation of water phase: heat water to 50-60°C, add stabilizer, emulsifier, antioxidant and antistatic agent in sequence, stir evenly to form a water phase;

[0022] Step 3: Preparation of oil phase: adding oil-soluble emulsifier to base fuel oil and stirring evenly to form oil phase;

[0023] Step 4: Preliminary emulsification: slowly add the water phase into the oil phase and stir at 55°C for 30 to 60 minutes to form colostrum;

[0024] Step 5, high shear emulsification: the colostrum is processed by a high shear emulsifier at a shear speed of 5000-8000 rpm for 30-60 minutes, and the droplet size is controlled at 1-5 μm;

[0025] Step 6, ultrasonic emulsification: the emulsion after high shear emulsification is placed in an ultrasonic emulsification device for treatment at a frequency of 20 to 25 kHz for 15 to 20 minutes;

[0026] Step 7: Add explosion-proof agent: slowly add the explosion-proof agent dispersion into the emulsion and stir evenly;

[0027] Step 8: Cooling and standing: Cool the emulsion to 25°C and stand for 24 hours to form safe fuel oil.

[0028] Preferably, in the high shear emulsification step, the shear rate is preferably 7000 rpm and the processing time is preferably 45 minutes.

[0029] Preferably, in the ultrasonic emulsification step, the temperature of the treatment process is controlled below 50° C. by a cooling system.

[0030] Preferably, the explosion-proof agent dispersion is prepared by dispersing nano silicon dioxide in deionized water at a mass ratio of 1:5, and dispersing the mixture by ultrasonic wave for 15 to 20 minutes.

[0031] Preferably, the cooling step uses a cooling water jacket or a circulating cooling system to reduce the temperature from 55° C. to 25° C., and during the static stage, observe through a transparent container whether there is stratification or precipitation.

[0032] Preferably, the storage stability test conditions of the safe fuel oil include storing at 25°C, 40°C and -10°C for 30 days to evaluate the stability change of the emulsion.

[0033] The present invention provides a safe fuel oil and a preparation method thereof. The invention has the following beneficial effects:

[0034] 1. The present invention significantly improves the stability of the emulsion by optimizing the emulsifier formula and adding modified zeolite powder. In particular, the storage period of the emulsion can reach more than two years, and the emulsion can remain stable without stratification or precipitation at different ambient temperatures. This improvement greatly improves the long-term storage of fuel oil and the requirements for emulsification stability during transportation, reduces the maintenance and replacement frequency of the emulsifier during storage, and saves users' maintenance costs.

[0035] 2. The emulsified fuel oil of the present invention effectively improves the combustion efficiency by optimizing the emulsifier and adding modified zeolite powder. The combustion efficiency is increased from 92% in Example 1 to 98% in Example 3, and the thermal efficiency is significantly improved. This enables the fuel to release more heat energy during the combustion process, reducing energy waste, while improving the working efficiency and operating stability of the equipment, reducing energy consumption, and having significant economic benefits.

[0036] 3. The present invention effectively reduces harmful emissions during the combustion process, especially NOx and particulate matter emissions. By optimizing the emulsifier formula, using modified zeolite powder and adding a combustion promoter, the NOx emissions of Example 3 were reduced by 35% and the particulate matter emissions were reduced by 43.75%. This improvement greatly reduces environmental pollution, meets more stringent environmental regulations, and is particularly suitable for use in industries and regions that require low emissions.

[0037] 4. The present invention improves the antioxidant performance of fuel oil by adding antioxidant BHT and modified zeolite powder to the fuel. The oxidation stability of the fuel is greatly improved, the storage period is extended, and oxidation deterioration under high temperature and long-term storage is prevented. The service life of fuel oil is extended by more than 20% compared with traditional fuel, the amount of waste fuel generated by oxidation deterioration is reduced, and it helps to reduce the maintenance frequency and cost of equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the specification of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Please see attached Figure 1 The embodiment of the present invention provides a safe fuel oil and a preparation method thereof, comprising:

[0041] Base fuel oil (70%~80%)

[0042] Light diesel: in compliance with national standard GB 19147-2016.

[0043] Biodiesel (optional): complies with GB / T 20828-2015 and can be mixed with light diesel at a mass ratio of 9:1 to improve fuel performance.

[0044] Water (15% to 25%)

[0045] Deionized water: conductivity ≤0.5μS / cm, to avoid impurities affecting the emulsification effect.

[0046] Emulsifier (2% to 4%)

[0047] Oil-soluble emulsifier: Span 80 (sorbitan monooleate), HLB value 4.3.

[0048] Water-soluble emulsifier: Tween 80, HLB value 15.

[0049] Emulsifier ratio: By adjusting the ratio of Span 80 and Tween 80, the target HLB value is 10-12, and the typical ratio is 3:7.

[0050] Stabilizer (0.5%~1%)

[0051] Polyvinyl alcohol (PVA): molecular weight of about 88,000, partial hydrolysis degree of 88%, increases the viscosity of the emulsion and prevents stratification.

[0052] Explosion-proof agent (0.3% to 0.5%)

[0053] Nano-silicon dioxide (SiO2): particle size 10-15nm, specific surface area>200m 2 / g, improving the explosion-proof performance of the fuel.

[0054] Antioxidant (0.2% to 0.3%)

[0055] 2,6-Di-tert-Butyl-p-cresol (BHT): prevents fuel from oxidative deterioration.

[0056] Antistatic agent (0.1% to 0.2%)

[0057] Quaternary ammonium compounds: improve the electrical conductivity of the fuel and prevent static electricity accumulation.

[0058] Combustion accelerator (optional, 0.1% to 0.2%)

[0059] Potassium nitrate (KNO3) or hydrogen peroxide (H2O2) (low concentration) to increase the burning rate

[0060] Stirred Reactor

[0061] Volume: 10L, stainless steel, corrosion-resistant.

[0062] Function: Equipped with temperature control system (heating and cooling), variable frequency stirrer (0~2000rpm).

[0063] High shear emulsifier

[0064] Rotation speed: 0~10,000rpm.

[0065] Function: stator / rotor structure, strong shear force and good emulsification effect.

[0066] Ultrasonic emulsification equipment

[0067] Frequency: 20kHz.

[0068] Power: 1000W.

[0069] Function: Equipped with cooling system to prevent overheating.

[0070] Measuring and Analytical Instruments

[0071] Particle size analyzer: Laser particle size analyzer, measuring range 0.01~100μm.

[0072] Viscometer: Rotational viscometer, measuring range 1~10,000mPa·s.

[0073] Flash point tester: closed cup method, in accordance with GB / T 261-2008.

[0074] Calorimeter: Oxygen bomb calorimeter, used to determine the calorific value of fuel.

[0075] Conductivity meter: Measuring range 0~200μS / cm.

[0076] Step 1: Pretreatment of base fuel oil

[0077] Filtering and removing impurities

[0078] Filter 70% to 80% of the base fuel oil through a 200-mesh filter to remove particulate impurities.

[0079] Heating to reduce viscosity

[0080] Heat the base fuel oil to 55°C to reduce the viscosity and facilitate subsequent mixing.

[0081] Step 2: Preparation of the aqueous phase

[0082] Heating water

[0083] Heat 15% to 25% deionized water to 55°C.

[0084] Dissolution stabilizer

[0085] At a stirring speed of 500 rpm, 0.5% to 1% PVA was slowly added and stirred for 1 hour until it was completely dissolved to form a uniform colloidal solution.

[0086] Add water-soluble emulsifiers and additives

[0087] Add water-soluble emulsifier Tween 80 (70% of the total amount of emulsifier) ​​and stir for 15 minutes to ensure thorough mixing.

[0088] 0.2% to 0.3% of antioxidant (BHT) and 0.1% to 0.2% of antistatic agent were added in sequence and stirred for 10 minutes to ensure uniform dispersion.

[0089] Step 3: Preparation of oil phase

[0090] Add oil-soluble emulsifier: Add oil-soluble emulsifier Span 80 (30% of the total emulsifier) ​​to the base fuel oil, stir at 300 rpm for 30 minutes to ensure that the emulsifier is fully dissolved.

[0091] Step 4: Preliminary emulsification

[0092] Mix the oil phase and the water phase. In a stirred reactor, add the oil phase first.

[0093] Adjust the stirring speed to 800 rpm and slowly add the water phase into the oil phase by dropwise addition to prevent uneven emulsification caused by adding all at once.

[0094] Stirring was continued for 45 minutes to form colostrum, which appeared as a milky white uniform liquid when observed with the naked eye.

[0095] Temperature control: the temperature is kept at 55℃ during the mixing process. Too high a temperature may cause the emulsion to break, while too low a temperature may affect the emulsification effect.

[0096] Step 5: High Shear Emulsification

[0097] Emulsification treatment: The colostrum is processed by a high shear emulsifier, the speed is set to 7000 rpm, and the processing time is 60 minutes.

[0098] Particle size monitoring: During the emulsification process, samples are taken every 15 minutes and the droplet size is measured using a laser particle size analyzer until the average particle size reaches 1 to 5 μm.

[0099] Step 6: Ultrasonic emulsification (optional)

[0100] Ultrasonic treatment: Place the emulsion after high shear emulsification in an ultrasonic emulsification device.

[0101] Parameter settings

[0102] Frequency: 20kHz.

[0103] Power: 1000W.

[0104] Duration: 20 minutes.

[0105] Temperature control, turn on the cooling system, keep the temperature below 50℃ to prevent the emulsion from being destroyed by overheating.

[0106] Step 7: Add Anti-Explosion Agent

[0107] The preparation of the explosion-proof agent dispersion is to mix 0.3% to 0.5% of nano-silicon dioxide with deionized water in a mass ratio of 1:5.

[0108] The mixture was treated with an ultrasonic disperser for 15 minutes to form a uniform nanodispersion.

[0109] Add and mix: slowly add the explosion-proof agent dispersion into the emulsion, stir at 500 rpm for 30 minutes to ensure that the nano-silica is evenly dispersed in the emulsion.

[0110] Step 8: Cooling and resting

[0111] Cool, stop heating, and use a cooling water jacket to reduce the emulsion temperature from 55°C to 25°C.

[0112] Let it stand and transfer the cooled emulsion to a clean, sealed container and let it stand for 24 hours.

[0113] Observe and check the appearance of the emulsion to ensure there is no stratification, precipitation or droplet aggregation.

[0114] Step 9: Quality Inspection

[0115] Physical properties testing

[0116] Particle size distribution: measured by laser particle size analyzer, the average particle size is 1-5μm and the particle size distribution is uniform.

[0117] Viscosity measurement: measured at 25°C using a rotational viscometer to ensure that the viscosity is suitable for the requirements of the fuel injection system.

[0118] Flash point determination: According to GB / T 261-2008 standard, the closed cup method is used for determination. The closed cup flash point is above 100 degrees.

[0119] Conductivity measurement: Use a conductivity meter to measure, the conductivity is not less than 50pS / m.

[0120] Chemical performance testing

[0121] Water content determination: Karl Fischer method is used to ensure that the water content is consistent with the designed value.

[0122] Acid value determination: Determine according to GB / T 264-1983 standard to ensure that the acid value is within the specified range to prevent corrosion to the equipment.

[0123] Combustion performance test

[0124] Calorific value determination: The lower calorific value was determined using an oxygen bomb calorimeter.

[0125] Combustion efficiency test: Test in a simulated combustion device, calculate the combustion efficiency and compare it with traditional fuel oil.

[0126] Emission test: Use an exhaust gas analyzer to measure emissions of CO, NOx, SOx, particulate matter, etc.

[0127] Safety performance testing

[0128] Explosion limit determination: Determined in accordance with GB / T 21868-2008 standard to ensure that the explosion range is narrowed.

[0129] Auto-ignition point determination: Using an auto-ignition point tester, the auto-ignition point is higher than 200°C.

[0130] Static electricity accumulation test: simulate actual operation, measure static electricity potential, and prevent static electricity risks.

[0131] Stability test

[0132] Storage stability: Store at 25°C, 40°C and -10°C for 30 days respectively, and check regularly for stratification, precipitation or emulsion aggregation.

[0133] Hot and cold cycle test: 10 hot and cold cycles (-10℃ to 50℃) were performed to evaluate the stability changes of the emulsion.

[0134] Step 10: Storage and Use

[0135] store

[0136] Container requirements: Use special anti-static and leak-proof containers.

[0137] Environmental requirements: Store in a dark, cool, well-ventilated place, avoid direct sunlight and high temperature environment.

[0138] use

[0139] Stirring: Before use after long-term storage, stir properly to ensure that the fuel is uniform.

[0140] Applicable equipment: Applicable to industrial boilers, internal combustion engines, generator sets and other equipment.

[0141] Embodiment 2:

[0142] Based on Example 1, this example successfully improves the emulsification stability and further improves the performance of safe fuel oil by optimizing the ratio of emulsifiers and adding special additives. By introducing polyether nonionic surfactants as emulsifiers, the stability, combustion efficiency and environmental adaptability of the emulsion are significantly improved. This example is superior to Example 1 in emulsification effect, combustion performance and storage stability.

[0143] Base fuel oil (70%~80%)

[0144] Light diesel: in compliance with national standard GB 19147-2016.

[0145] Biodiesel (optional): Complies with GB / T 20828-2015, mixed at a mass ratio of 10:1 to improve the biodegradability of the fuel.

[0146] Water (15% to 25%)

[0147] Deionized water: conductivity ≤0.5μS / cm, to ensure the stability of the emulsion.

[0148] Emulsifier (2% to 4%)

[0149] Oil-soluble emulsifier: Span 80 (sorbitan monooleate), HLB value 4.3.

[0150] Water-soluble emulsifier: polyether nonionic emulsifier, such as Triton X-100, HLB value 13. This emulsifier has better water solubility and emulsification stability.

[0151] Emulsifier ratio: The ratio of oil-soluble emulsifier to water-soluble emulsifier is 4:6 to optimize the emulsification effect.

[0152] Stabilizer (0.5%~1%)

[0153] Polyvinyl alcohol (PVA): molecular weight of about 88,000, partial hydrolysis degree of 88%, increases the viscosity of the emulsion and improves long-term storage stability.

[0154] Explosion-proof agent (0.3% to 0.5%)

[0155] Nano-silicon dioxide (SiO2): particle size 10-15nm, specific surface area>200m 2 / g, improving the explosion-proof performance of the fuel.

[0156] Antioxidant (0.2% to 0.3%)

[0157] 2,6-Di-tert-Butyl-p-cresol (BHT): prevents fuel oil from oxidation and deterioration, extending its service life.

[0158] Antistatic agent (0.1% to 0.2%)

[0159] Quaternary ammonium compounds: improve the electrical conductivity of the fuel and prevent static electricity accumulation.

[0160] Combustion accelerator (optional, 0.1% to 0.2%)

[0161] Potassium nitrate (KNO3) or hydrogen peroxide (H2O2) (low concentration) to increase the burning rate

[0162] The equipment used in this embodiment is basically the same as that in the first embodiment, including a stirred reactor, a high shear emulsifier, an ultrasonic emulsifier, a particle size analyzer, a viscometer, etc.

[0163] Step 1: Pretreatment of base fuel oil

[0164] Filtration and impurity removal: The base fuel oil is first filtered through a 200-mesh filter to remove particulate impurities.

[0165] Heating viscosity reduction: Heat the base fuel oil to 55°C to reduce its viscosity.

[0166] Step 2: Preparation of the aqueous phase

[0167] Heat water: Heat deionized water to 55°C.

[0168] Dissolution stabilizer: Slowly add 0.5% to 1% PVA and continue stirring for 1 hour until it is completely dissolved to form a uniform aqueous solution.

[0169] Addition of emulsifiers and other additives:

[0170] Mix a polyether nonionic emulsifier (such as Triton X-100) and Span 80, adjust the ratio to 4:6, and stir evenly.

[0171] Add antioxidant (BHT) and antistatic agent and stir for 10 minutes to ensure even dispersion.

[0172] Step 3: Preparation of oil phase

[0173] Mix the oil-soluble emulsifier (Span 80) with the base fuel oil and stir for 30 minutes to ensure that the emulsifier is completely dissolved.

[0174] Step 4: Preliminary emulsification

[0175] Mix the oil phase and the water phase: Mix the oil phase and the water phase, and pour the oil phase into the stirred reactor first.

[0176] The aqueous phase was slowly added at a stirring speed of 800 rpm, stirring was continued for 45 minutes, and the initial formation of an emulsion was observed.

[0177] Step 5: High Shear Emulsification

[0178] The colostrum was processed by a high shear emulsifier, the speed was set to 8000 rpm, the processing time was 60 minutes, and the droplet size should be controlled at 1 to 5 μm.

[0179] Step 6: Ultrasonic emulsification (optional)

[0180] Ultrasonic treatment: The emulsion after high shear emulsification was placed in an ultrasonic emulsification device, with the frequency set to 20 kHz, the power to 1000 W, and the treatment time to 20 minutes.

[0181] Step 7: Add Anti-Explosion Agent

[0182] Slowly add the nano-silica dispersion into the emulsion and stir for 30 minutes to ensure uniform dispersion.

[0183] Step 8: Cooling and resting

[0184] Cool the emulsion to 25°C and let it stand for 24 hours. Check the stability of the emulsion to ensure there is no stratification or precipitation.

[0185] Step 9: Quality Inspection

[0186] Conduct tests on particle size distribution, viscosity, flash point, combustion performance, etc. to ensure that the physical, chemical and combustion properties of the emulsion meet the standard requirements.

[0187] Step 10: Storage and Use

[0188] Ensure that the emulsified fuel oil is stored in a dedicated container, away from direct sunlight and high temperature environment, and should be properly stirred before use to ensure that the emulsion is uniform.

[0189] Table 1 Data comparison table of embodiment 1 and 2

[0190] Performance Indicators Embodiment 1 Embodiment 2 NOx emissions 100ppm 80ppm Particle emissions <![CDATA[80mg / m 3 ]]> <![CDATA[56mg / m 3 ]]> Combustion temperature(℃) 1000℃ to 1200℃ 1000℃ to 1200℃ Storage temperature adaptability 5℃ to 40℃ -10℃ to 45℃ Oil-in-water emulsion droplet size (μm) 5~10μm 1~5μm Antistatic effect <1μS / cm 0.5μS / cm Explosion-proof performance standard improve

[0191] The second embodiment has significant improvements in reducing NOx and particulate matter emissions, especially during the combustion process, where emissions are greatly reduced, meeting more stringent environmental standards.

[0192] The second embodiment not only performs better at conventional storage temperature, but also remains stable at lower temperature and is adaptable to a wider range of usage environments.

[0193] The addition of nano-silicon dioxide improves the explosion-proof performance of Example 2, and the fuel is safer under high temperature and high pressure environment.

[0194] Embodiment three:

[0195] Based on Example 1 and Example 2, this example further optimizes emulsification stability, combustion efficiency, antioxidant capacity and low temperature performance by introducing surfactant compounding technology and ultrafine powder addition. In particular, by using modified zeolite powder and compounded emulsifier, the storage stability and thermal efficiency of fuel oil during combustion are significantly improved, while harmful emissions are reduced. The improvement effect of Example 3 is more significant than that of Example 2, especially in terms of antioxidant performance and low temperature starting performance.

[0196] Base fuel oil (70%~75%)

[0197] Light diesel: in compliance with national standard GB 19147-2016.

[0198] Biodiesel: in accordance with GB / T 20828-2015, mixed at a mass ratio of 10:1.

[0199] Water (20% to 25%)

[0200] Deionized water: conductivity ≤0.5μS / cm, to ensure the stability of the emulsion.

[0201] Emulsifier (2% to 4%)

[0202] Oil-soluble emulsifier: Span 80 (sorbitan monooleate), HLB value 4.3.

[0203] Water-soluble emulsifier: polyether nonionic emulsifier Triton X-100, HLB value 13.

[0204] Compound emulsifier: Compound emulsifier is a mixture of oil-soluble emulsifier and water-soluble emulsifier in a 1:1 ratio.

[0205] Stabilizer (1%~1.5%)

[0206] Polyvinyl alcohol (PVA): molecular weight 88,000, partial hydrolysis degree 88%, improves emulsion stability.

[0207] Antioxidant (0.3% to 0.5%)

[0208] BHT: Prevents fuel from oxidation and deterioration, extending storage time.

[0209] Explosion-proof agent (0.3% to 0.5%)

[0210] Nano-silicon dioxide (SiO2): particle size 10-15nm, specific surface area>200m 2 / g, enhance explosion-proof performance.

[0211] Combustion accelerator (0.1%~0.3%)

[0212] Calcium chloride (CaCl2): Improves combustion efficiency.

[0213] Ultrafine powder additive (0.5%~1%)

[0214] Modified zeolite powder: used to improve thermal stability during combustion and reduce smoke and carbon deposits during combustion.

[0215] This embodiment is the same as the first and second embodiments, and uses the following equipment:

[0216] Stirred reactor, high shear emulsifier, ultrasonic emulsification equipment.

[0217] Particle size analyzer, viscometer, thermal stability tester.

[0218] Environmental emission testing equipment (NOx, particulate matter, CO, etc. testing equipment).

[0219] Step 1: Pretreatment of base fuel oil

[0220] Filtration and impurity removal: The base fuel oil is first filtered through a 200-mesh filter to remove impurities.

[0221] Heating to reduce viscosity: Heat the base fuel oil to 60°C to reduce its viscosity and facilitate emulsification.

[0222] Step 2: Preparation of the aqueous phase

[0223] Heat water: Heat deionized water to 60°C.

[0224] Dissolution stabilizer: Slowly add 0.8% to 1.5% PVA and stir until it is completely dissolved to form a uniform aqueous solution.

[0225] Emulsifier ratio: Add the compound emulsifier (Span 80 and Triton X-100 in a ratio of 1:1) into the water phase and stir evenly.

[0226] Add antioxidant: add 0.3% to 0.5% BHT and stir for 5 minutes.

[0227] Step 3: Preparation of oil phase

[0228] Mix the oil-soluble emulsifier (Span 80) with the base fuel oil and stir for 30 minutes to ensure that the emulsifier is completely dissolved.

[0229] Step 4: Preliminary emulsification

[0230] Mix the oil phase and the water phase: slowly add the oil phase into the stirred reactor and evenly add the water phase.

[0231] The stirring speed was set to 1000 rpm and stirring was continued for 45 minutes until an emulsion was initially formed.

[0232] Step 5: High Shear Emulsification

[0233] The primary emulsion was processed by a high shear emulsifier, the speed was set to 9000 rpm, the processing time was 60 minutes, and the droplet size should be controlled at 2 to 6 μm.

[0234] Step 6: Ultrasonic emulsification (optional)

[0235] Ultrasonic treatment: The emulsion after high shear emulsification was placed in an ultrasonic emulsification device with a frequency of 20 kHz, a power setting of 1500 W, and a treatment time of 30 minutes.

[0236] Step 7: Ultrafine powder addition

[0237] Add modified zeolite powder: Add the modified zeolite powder into the emulsion at a ratio of 0.5% to 1%, and stir for 30 minutes to ensure uniform dispersion.

[0238] Step 8: Cooling and resting

[0239] Cool the emulsion to 30°C, let it stand for 24 hours, and check the stability of the emulsion to ensure there is no stratification or precipitation.

[0240] Step 9: Quality Inspection

[0241] The emulsion is subjected to a series of tests such as particle size, viscosity, flash point, and combustion performance to ensure that it meets the relevant standards for safe fuel oil.

[0242] Step 10: Storage and Use

[0243] Store emulsified fuel oil in a dedicated container, away from direct sunlight and high temperature environment. Stir it properly before use to ensure that the emulsion is uniform.

[0244] Table 2 Data comparison table of Examples 1 and 3

[0245]

[0246]

[0247] NOx emissions: reduced from 100 ppm in Example 1 to 65 ppm in Example 3, a reduction of 35%.

[0248] Particle emission: from 80mg / m 3 Reduce to 45 mg / m 3 , a decrease of 43.75%.

[0249] Environmental protection emission standards: Example 3 meets the national first-level emission standards, and the environmental protection performance is significantly improved.

[0250] Embodiment 1: The adaptable temperature range is 5°C to 40°C.

[0251] Embodiment 2: Extend to -10℃~45℃.

[0252] Embodiment 3: Further expanded to -15°C to 50°C, suitable for more severe environmental conditions.

[0253] Improved conductivity: The conductivity of Example 3 reaches 0.8 μS / cm, and the risk of static electricity accumulation is further reduced.

[0254] Antioxidation performance: compared with Example 1, the antioxidation performance of Example 3 is improved by 20%, and the fuel is less likely to be oxidized and deteriorated.

[0255] Oxidation stability: Oxidation stability is increased from 800 hours to 960 hours, and the storage life is extended.

[0256] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A safe fuel oil, characterized in that: The fuel oil is an emulsified fuel oil, which comprises the following components by mass percentage: 70% to 80% of base fuel oil, including light diesel, biodiesel, ethylene glycol, high alcohol or their mixtures; Water 15% to 25%, deionized water or softened water; 2% to 4% of an emulsifier, including an oil-soluble emulsifier and a water-soluble emulsifier, wherein the oil-soluble emulsifier is Span 80 and the water-soluble emulsifier is Tween 80; Stabilizer 0.5% to 1%, which is polyvinyl alcohol or xanthan gum; Explosion-proof agent: 0.3% to 0.5%, which is nano silicon dioxide or nano aluminum oxide; Antioxidant 0.2% to 0.3%, 2,6-di-tert-butyl-p-cresol; Antistatic agent 0.1% to 0.2%, which is a quaternary ammonium salt compound; The combustion accelerator is 0.1% to 0.2%, which is potassium nitrate or low concentration hydrogen peroxide.

2. A safe fuel oil according to claim 1, characterized in that: The HLB value of the emulsifier is 10-12, and is obtained by compounding Span 80 and Tween 80 in a mass ratio of 3:

7.

3. A safe fuel oil according to claim 1, characterized in that: The base fuel oil is prepared by mixing light diesel and biodiesel in a mass ratio of 9:

1.

4. A safe fuel oil according to claim 1, characterized in that: The particle size of the explosion-proof agent is 10 to 15 nanometers, and the specific surface area is greater than 200 m 2 / g, uniformly dispersed in the emulsion by ultrasonic dispersion technology.

5. A method for preparing safe fuel oil, according to the safe fuel oil according to claims 1-4, characterized in that: The following steps are involved: Step 1: Pretreatment of base fuel oil: filter and remove impurities from the base fuel oil and heat it to 50-60°C; Step 2, preparation of water phase: heat water to 50-60°C, add stabilizer, emulsifier, antioxidant and antistatic agent in sequence, stir evenly to form a water phase; Step 3: Preparation of oil phase: adding oil-soluble emulsifier to base fuel oil and stirring evenly to form oil phase; Step 4: Preliminary emulsification: slowly add the water phase into the oil phase and stir at 55°C for 30 to 60 minutes to form colostrum; Step 5, high shear emulsification: the colostrum is processed by a high shear emulsifier at a shear speed of 5000-8000 rpm for 30-60 minutes, and the droplet size is controlled at 1-5 μm; Step 6, ultrasonic emulsification: the emulsion after high shear emulsification is placed in an ultrasonic emulsification device for treatment at a frequency of 20 to 25 kHz for 15 to 20 minutes; Step 7: Add explosion-proof agent: slowly add the explosion-proof agent dispersion into the emulsion and stir evenly; Step 8: Cooling and standing: Cool the emulsion to 25°C and stand for 24 hours to form safe fuel oil.

6. A method for preparing safe fuel oil according to claim 1, characterized in that: In the high shear emulsification step, the shear rate is preferably 7000 rpm and the processing time is preferably 45 minutes.

7. A method for preparing safe fuel oil according to claim 1, characterized in that: In the ultrasonic emulsification step, the temperature of the treatment process is controlled below 50° C. by a cooling system.

8. A method for preparing safe fuel oil according to claim 1, characterized in that: The explosion-proof agent dispersion is prepared by dispersing nano silicon dioxide in deionized water at a mass ratio of 1:5 and performing ultrasonic dispersion for 15 to 20 minutes.

9. A method for preparing safe fuel oil according to claim 1, characterized in that: The cooling step uses a cooling water jacket or a circulating cooling system to reduce the temperature from 55° C. to 25° C., and during the static stage, observe through a transparent container whether there is stratification or precipitation.

10. A method for preparing safe fuel oil according to claim 1, characterized in that: The storage stability test conditions of the safe fuel oil include storing at 25°C, 40°C and -10°C for 30 days to evaluate the stability change of the emulsion.

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