KR102580224B1 - Recycled fuel composition using waste oil and emulsion fuel oil comprising the same - Google Patents

Abstract

The recycled fuel composition using waste oil according to the present invention and the emulsion-type fuel oil containing the same contain ingredients such as hydrogen peroxide, emulsifier, and activator, and thus have excellent fuel properties such as calorific value and combustion efficiency, and have excellent initial fuel properties even after long-term storage. It has the effect of demonstrating fuel characteristics. In addition, although it is environmentally friendly by reusing waste oil, it has the effect of explosively increasing combustion activity during combustion and has the effect of minimizing the generation of air pollutants during combustion.

Description

Recycled fuel composition using waste oil and emulsion fuel oil comprising the same}

The present invention relates to a recycled fuel composition using waste oil and an emulsion-type fuel oil containing the same.

In 2004, the government of the Republic of Korea completely revised the ‘Petroleum Business Act’ to the ‘Petroleum and Petroleum Alternative Fuel Business Act’ in order to ensure smooth supply and demand of petroleum resources and stabilize prices, and began the introduction of alternative petroleum fuels. Substitute for petroleum fuel refers to fuel (excluding coal and natural gas) that can be used in place of petroleum products without fundamental structural changes in petroleum product combustion facilities. The government regulates biodiesel, bioethanol, coal liquefied oil, emulsified fuel oil, and natural bitumen. It is classified into 5 categories including:

Among them, emulsified fuel oil is a fuel that is emulsified by mixing refined oil or heavy fuel with water and emulsifier. It improves the combustibility of heavy fuel and removes dust, nitrogen oxides (NO _x ), and sulfur oxides (SO ), which are the main causes of air pollution. _x ), it is a fuel that can reduce the generation of smoke and other air pollutants. This type of emulsified fuel oil does not have to rely on importing raw materials like biofuel, so when commercialized, it has the advantage of being able to expand its use more quickly than other petroleum alternative fuels.

However, emulsified fuel oil has a state in which the water phase is dispersed in the form of fine particles in the oil phase, so when left for a long time, it has the disadvantage of poor storage stability, such as agglomeration or layer separation into a water layer and an oil layer. In addition, emulsified fuel oil contains about 5 to 30% water, so it has the disadvantage of reducing the calorific value as the oil content is lower compared to 100% oil. In this way, emulsified fuel oil has the advantages of increasing combustion efficiency and suppressing air pollutants, but it is less stable and cannot exhibit excellent initial fuel characteristics as the storage period increases, and the calorific value decreases as the oil content is small. There is.

Meanwhile, industrially, the amount of waste oil generated is estimated to be about 70% of sales, based on the sales volume of new oil sold for application in automobiles and industrial fields. Since these waste oils can be used as useful resources, a significant portion is currently used. It is recycled into recycled refined oil or fuel oil.

However, when recycling it as fuel oil, the combustion characteristics are poor due to various impurities such as heavy metal compounds, chlorine compounds, and sulfur compounds, so it cannot be recycled properly.

In particular, when manufacturing emulsified fuel oil, when oil is used as waste oil, that is, when waste oil is recycled and used as emulsified fuel oil, it is not easy to apply it as fuel industrially compared to when refined bunker C oil is used. In general, when waste oil is used as fuel oil, thermal efficiency is reduced due to incomplete combustion during combustion, and it can also become a cause of other pollution.

Therefore, there is a need to develop emulsified fuel oil that can be universally recycled from waste oil and applied to emulsified fuel oil, has excellent combustion characteristics such as calorific value and combustion efficiency, as well as excellent storage stability.

Korean Patent Publication No. 10-2001-0045991 (2001.06.05)

The purpose of the present invention is to provide a recycled fuel composition using waste oil that has excellent fuel properties such as calorific value and combustion efficiency and can exhibit excellent initial fuel properties even after long-term storage, and an emulsion-type fuel oil containing the same.

Another object of the present invention is to provide a recycled fuel composition using waste oil, which is environmentally friendly by reusing waste oil and has explosively increased combustion activity during combustion, and an emulsion-type fuel oil containing the same.

Another object of the present invention is to provide a recycled fuel composition using waste oil that can minimize the generation of air pollutants and an emulsion-type fuel oil containing the same.

The present invention provides a recycled fuel composition using waste oil, and the recycled fuel composition using waste oil includes waste oil, hydrogen peroxide, and an inorganic emulsifier.

A recycled fuel composition using waste oil according to an example of the present invention may include 53 to 80% by weight of the waste oil, 17 to 45% by weight of the hydrogen peroxide solution, and 0.1 to 3% by weight of the inorganic emulsifier.

The recycled fuel composition using waste oil according to an example of the present invention may further include an activator, and the activator may include sulfated polysaccharide derived from brown algae.

In one example of the present invention, the brown algae-derived sulfated polysaccharide may include fucoidan.

A recycled fuel composition using waste oil according to an example of the present invention includes 53 to 80% by weight of the waste oil, 17 to 45% by weight of hydrogen peroxide, 0.1 to 3% by weight of the inorganic emulsifier, and 0.1 to 2% by weight of the activator. can do.

In one example of the present invention, the hydrogen peroxide solution may contain 68% by weight or more of hydrogen peroxide.

In one example of the present invention, the inorganic emulsifier may include an inorganic powder having surface activity ability based on Pickering emulsion (depletion force).

In one example of the present invention, the inorganic emulsifier may include any one or two or more selected from hydroxides, chlorides, nitrides, carbonates, and sulfur oxides of Group 1 or Group 2 metals.

The recycled fuel composition using waste oil according to an example of the present invention may further include an organic emulsifier, and the organic emulsifier may include one or two selected from ester-based emulsifiers and ether-based emulsifiers.

Additionally, the present invention provides an emulsion-type fuel oil containing a recycled fuel composition using the waste oil.

Recycled emulsion-type fuel oil using waste oil according to an example of the present invention includes an aqueous dispersed phase containing hydrogen peroxide of the fuel composition; and a continuous oil phase containing waste oil of the fuel composition.

In one example of the present invention, the average droplet size of the dispersed phase may be 1 to 10 ㎛.

In the recycled emulsion type fuel oil using waste oil according to an example of the present invention, the change in emulsion particle size may be less than 10% when the emulsion type fuel oil is left in a non-vibrating environment at 25°C and 1 atm for 20 days. there is.

The recycled fuel composition using waste oil according to the present invention and the emulsion-type fuel oil containing the same have excellent fuel properties such as calorific value and combustion efficiency, and can exhibit excellent initial fuel properties even after long-term storage.

The recycled fuel composition using waste oil according to the present invention and the emulsion-type fuel oil containing the same are environmentally friendly by reusing waste oil, but have the effect of explosively increasing combustion activity during combustion.

The recycled fuel composition using waste oil according to the present invention and the emulsion-type fuel oil containing the same have the effect of minimizing the generation of air pollutants during combustion.

Hereinafter, a recycled fuel composition using waste oil according to the present invention and an emulsion-type fuel oil containing the same will be described in detail.

Unless there is another definition in the technical and scientific terms used in this specification, they have meanings commonly understood by those skilled in the art to which this invention pertains, and the gist of the present invention is not unnecessarily explained in the following description. Descriptions of known functions and configurations that may be unclear are omitted.

The singular form of the terms used in this specification may be interpreted to also include the plural form unless otherwise specified.

Numerical ranges as used herein include lower and upper limits and all values within that range, increments logically derived from the shape and width of the range being defined, all doubly defined values, and upper and lower limits of numerical ranges defined in different forms. Includes all possible combinations of Unless otherwise specified in the specification of the present invention, values outside the numerical range that may occur due to experimental error or rounding of values are also included in the defined numerical range.

'Include' mentioned in this specification is an open description that has the same meaning as expressions such as 'comprises', 'contains', 'has', 'characterized by', etc., and includes elements that are not additionally listed, Does not exclude materials or processes.

The unit of % used without special mention in this specification means weight% unless otherwise defined.

The present invention provides a recycled fuel composition using waste oil, and the fuel composition includes waste oil, hydrogen peroxide, and an inorganic emulsifier. The fuel composition is an emulsion-type fuel oil that exists in an emulsion phase in which an oil phase and an aqueous phase are mixed.

General emulsion-type fuel oil consisting of oil, water, and emulsifier has a low calorific value and poor combustion activity, and especially when waste oil is used as an oil component, the quality of the fuel oil is very low. On the other hand, the emulsion-type fuel oil according to the present invention contains hydrogen peroxide and an inorganic emulsifier even though it reuses waste oil, so that a large amount of oxygen is generated by hydrogen peroxide during combustion, which can explosively increase combustion activity. Therefore, the present invention provides high-quality fuel oil with a higher calorific value and excellent combustion activity compared to the conventional fuel oil, even though it is a water-in-oil (W/O) emulsion fuel oil in which the main component is oil and water is the dispersed phase.

In particular, the fuel composition according to the present invention, that is, emulsion-type fuel oil, not only has excellent combustion characteristics such as calorific value and combustion activity even though it contains waste oil as a main ingredient, but also has excellent long-term storage stability through additional or specific compositions described later. . As such, the fuel composition according to the present invention generates a large amount of oxygen due to hydrogen peroxide during combustion in a high temperature environment, thereby explosively increasing combustion activity and greatly improving long-term storage stability at low temperatures.

The hydrogen peroxide solution contains hydrogen peroxide and water. Hydrogen peroxide decomposes during combustion and generates a large amount of oxygen radicals, thereby causing complete combustion of the fuel as much as possible even if the amount of oxygen flowing in from the outside is small. In addition to improving combustion activity, it is possible to suppress excessive generation of impurities such as ash that may occur due to combustion.

The composition ratio of the emulsified fuel oil may be any emulsion-type fuel oil containing 30% by weight or less of water, which is commonly used in the emulsified fuel oil field. For example, the fuel composition according to the present invention may include 53 to 80% by weight of the waste oil, 17 to 45% by weight of the hydrogen peroxide, and 0.1 to 3% by weight of the inorganic emulsifier. Specifically, the waste oil 62 to 73% by weight, 25 to 35% by weight of hydrogen peroxide, and 0.1 to 3% by weight of the inorganic emulsifier. However, this is only described as a preferred example and the present invention is not limited thereto.

At this time, the hydrogen peroxide concentration of the hydrogen peroxide water is not greatly limited, but it may be preferable to include 68% by weight or more, specifically 70% by weight or more, of hydrogen peroxide based on the total weight of the hydrogen peroxide water. Here, the upper limit value of hydrogen peroxide concentration is not greatly limited and may be, for example, 90% by weight, specifically 80% by weight. At a hydrogen peroxide concentration of 68% by weight, specifically 67% by weight or less, the heat energy generated by decomposition of hydrogen peroxide is absorbed as latent heat of vaporized water, making it difficult to increase the temperature above the boiling point of hydrogen peroxide. Therefore, all of the heat energy generated from hydrogen peroxide is not released to the outside, so the effect of improving calorific value by hydrogen peroxide may be minimal. On the other hand, when the concentration of hydrogen peroxide is 68% by weight or more, specifically 70% by weight or more, heat generation by hydrogen peroxide is added in addition to heat generated by combustion of waste oil in the fuel composition due to an exothermic reaction in which hydrogen peroxide is decomposed during combustion, thereby increasing the unit of fuel composition. The calorific value per weight can be significantly increased.

The inorganic emulsifier may be any inorganic compound capable of emulsifying oil and water. For example, Pickering emulsion technology, that is, an inorganic powder having surface activity properties based on depletion force may be used. Various types of inorganic powders can be used as long as they can act as a surfactant by adsorbing at the oil-water interface so that waste oil and hydrogen peroxide can form an emulsion.

Since the fuel composition according to the present invention is a W/O emulsion composition, it is preferable to use a lipophilic inorganic powder having a surface characteristic of a water contact angle of 90 degrees or more. The inorganic powder has a surface activity ability based on Pickering emulsion (depletion force) in the fuel composition, and more preferably, an inorganic powder that has been appropriately surface modified to have a surface activity ability can be used. As an example of surface modification, chemical grafting can be used to chemically bond organic molecules to the surface of the powder, or physical adsorption can be used. For example, when the inorganic powder has a hydrophilic surface, an inorganic powder surface modified to be hydrophobic by grafting or physically adsorbing a lipophilic (hydrophobic) organic compound to the surface of the inorganic powder may be used.

An appropriate material for modifying the surface of the inorganic powder may be used depending on the surface properties (hydrophilicity, hydrophobicity). In general, the surface of the inorganic powder itself is hydrophilic, so the surface of the inorganic powder can be treated with a material with hydrophobic properties. Examples include higher fatty acids such as stearic acid, palmitic acid, oleic acid, and linoleic acid, acrylic, epoxy, and olefin. Hydrophobic polymers such as polymers, etc. can be mentioned. However, this is only described as a preferred example and the present invention is not limited thereto.

Types of the inorganic powder may include, for example, any one or two or more selected from oxides, carbonates, and hydroxides of Group 1 or Group 2 metals. Examples of Group 1 metals, that is, alkali metals, include sodium and potassium, and examples of Group 2 metals, that is, alkaline earth metals, include magnesium and calcium. As a specific example, MgO, Mg(OH) ₂ , CaCO ₃ , MgCO ₃ , Ca(OH) ₂ , CaO, etc., which have relatively low solubility in water, may be used.

As a preferred example, when a Group 2 metal, especially a magnesium compound, is used as the inorganic powder of the inorganic emulsifier, hydrogen peroxide can act as an oxidizing agent and undergo an explosive decomposition reaction in a high temperature environment, i.e., when burned, and hydrogen peroxide can be used in a low temperature environment, i.e., when stored. The problem of continuous decomposition over a long period of time can be suppressed. Preferred specific compounds thereof include MgO and Mg(OH) ₂ , which have low solubility in water. Therefore, long-term storage is further improved and the initial excellent combustion characteristics can be maintained for a longer period of time.

As a preferred example of the inorganic emulsifier, stearic acid-coated calcium carbonate (CaCO ₃ ) or magnesium oxide (MgO) particles may be used. Inorganic powder particles surface-modified with stearic acid can be manufactured by spraying molten stearic acid at high temperature onto the inorganic powder particles and adsorbing the stearic acid on the surface of the particles. However, this is only described as a preferred example and the present invention is not limited thereto.

The average particle size of the inorganic powder may be sufficient to exhibit surface activity. For example, it can be widely applied from nano to micro sizes, but nano size may be preferable in terms of emulsion stability. As a specific example, the average size may be 10 to 500 nm, specifically 50 to 400 nm, and more specifically 100 to 350 nm. However, this is only described as a preferred example and the present invention is not limited thereto.

The average specific surface area of the inorganic powder may be sufficient to exhibit surface activity ability, for example, 5 to 500 m ² /g, specifically 10 to 300 m ² /g, more specifically 15 to 100 m ^{2 /g} . It may be g. However, this is only described as a specific example and the present invention is not limited thereto.

As mentioned above, there is a problem in that hydrogen peroxide generally decomposes continuously over time. However, when the fuel composition according to the present invention further includes an activator described later, it continues to decompose when exposed to a low temperature environment such as storage for a long period of time. It may have the effect of preventing decomposition and improving emulsification with waste oil.

That is, the recycled fuel composition using waste oil according to a preferred example may further include an activator described later along with waste oil, an inorganic emulsifier, and hydrogen peroxide. The activator not only causes an exothermic reaction in which hydrogen peroxide is not easily decomposed at low temperatures but explosively decomposes at high temperatures such as a combustion environment, and can also serve as an organic emulsifier along with the inorganic emulsifier.

As described above, the fuel composition according to the present invention may contain a significant amount of hydrogen peroxide, approximately 20% of the total weight of the fuel composition, and even if it contains a large amount of hydrogen peroxide, it may contain an activator described later, so it can be used for a long period of time. When stored, the low-temperature decomposition characteristics of hydrogen peroxide can be minimized.

The activator may include sulfated polysaccharide derived from brown algae. Specifically, the sulfated polysaccharide derived from brown algae may include fucoidan. In detail, when an activator containing sulfated polysaccharide derived from brown algae is used together with hydrogen peroxide, which is a component of the fuel composition according to the present invention, the activator not only acts as a radical scavenger to suppress the production of radicals due to decomposition of hydrogen peroxide. , It also acts as an organic emulsifier, and the emulsifying properties that may be insufficient with the inorganic emulsifier alone can be complemented by an organic emulsifier. It may be difficult to stabilize the emulsification of the oil phase and the water phase for a long period of time with the inorganic emulsifier alone, but when the activator is used together with the inorganic emulsifier, the activator can maintain the emulsion of the fuel composition more stably as an organic emulsifier.

In addition, by using the hydrogen peroxide together with the activator, there is an effect of relatively reducing the ratio of sulfur trioxide (SO ₃ ) among trace amounts of sulfur oxides that can be discharged by sulfur contained in the activator. In detail, general emulsified fuel oil can suppress nitrogen oxide emissions because the combustion temperature is lowered by atomization of water during combustion, but if the fuel oil contains sulfur, the proportion of sulfur trioxide among the sulfur oxides emitted may increase. Since sulfur trioxide can cause corrosion of the internal wall of the combustion chamber and also causes white smoke when discharged through the stack, it is desirable to reduce the proportion of sulfur trioxide among sulfur oxides. When the fuel composition according to the present invention further includes the activator together with hydrogen peroxide, not only the decomposition inhibition effect of hydrogen peroxide and the organic emulsifier effect are exhibited by the activator during storage, but also the sulfur that can be produced by the activator A complementary synergy effect can be realized in which hydrogen peroxide has the effect of relatively reducing the proportion of sulfur trioxide among oxides.

Since the brown algae-derived sulfuric acid polysaccharide has two or more sulfate groups and may cause sulfide gas as described above, it may be preferable to use the content at 2% by weight or less, specifically, at 1% by weight or less. That is, the fuel composition according to the present invention may include 0.1 to 2% by weight, specifically 0.1 to 1% by weight, of the activator.

In a preferred example, when the weight ratio of the hydrogen peroxide and the activator satisfies 100:1 to 5 within the above-mentioned composition ratio range, that is, the fuel composition contains 1 to 5 parts by weight of the activator based on 100 parts by weight of hydrogen peroxide. In this case, along with the above-described effects, the proportion of sulfur trioxide among sulfur oxides can be relatively reduced, while at the same time the amount of sulfur oxide itself generated can be minimized.

It may be desirable for the fuel composition according to the present invention to further include an organic emulsifier. When the organic emulsifier is further used, the stability of the emulsion system, which may be insufficient with the inorganic emulsifier, can be further improved. The organic emulsifier may be any organic compound capable of acting as a surfactant capable of emulsifying water and oil, and may include, for example, one or two selected from ester-based emulsifiers and ether-based emulsifiers. Specifically, examples of ester emulsifiers include one or more oleate salts selected from sorbitan monostearate, sorbitan monooleate, and sorbitan trioleate. there is. Ester compounds include esters produced by any combination of each fatty acid and higher alcohol. Among these, ester compounds of sugar alcohols may be better. Representative examples thereof include Sorbitan monooleate, Sorbitan dioleate, Sorbitan trioleate, Sorbitan tristearate, Sorbitan monostearate ( Sorbitan monostearate, Sorbitan monopalmitate, Sorbitan monolaurate, Mannitan monooleate, Mannitan dioleate, Mannitan trioleate trioleate), Mannitan tristearate, Mannitan monostearate, Mannitan monopalmitate, Polyglycol-fatty acid ester, diglycol-lau Diglycol-laurate, diglycol-oleate, diglycol-stearate, Diethylene-glycol laurate, propylene-glycol monolaurate (Propylene) -glycol monolaurate), Propylene-glycol monooleate, Propylene-glycol monostearate, Glycerol-Monostearate, Glycerol- Monooleate), glycerol-monostearate (Glycerol-Monostearate), etc. may include any one or two or more selected from the group. As a specific example, polyoxyethylene nonylphenyl ether may be used. However, this is only described as a specific example and the present invention is not limited thereto.

When the organic emulsifier is used, its content is not greatly limited, but for example, it may be included in the fuel composition at 0.1 to 3% by weight, specifically 0.1 to 2% by weight, based on the total weight of the fuel composition. However, this is only described as a preferred example and the present invention is not limited thereto.

In one example of the present invention, the fuel composition may further include other additives depending on the required purpose. Examples of the additive include stabilizers, corrosion inhibitors, dehazing agents, pH regulators, other combustion improvers, antistatic agents, antioxidants, antifoaming agents, pigments, fragrances, gelling agents, denitrifying agents, desulfurizing agents, viscosity regulators, and pour point lowering agents. It may include any one or more than two. However, this is only described as a specific example, and of course, additives for various purposes and uses that can be used in fuel oil can be used.

As described above, the recycled fuel composition using waste oil according to the present invention is an emulsion type fuel oil, and includes an aqueous dispersed phase containing hydrogen peroxide; and a continuous oil phase containing waste oil.

In the emulsion-type fuel oil, the smaller the average droplet size of the dispersed phase can be advantageous for combustion activity by improving the contact area between oil and air, for example, it can be 1 to 10 ㎛. When fuel oil is injected into the cylinder through an injector, water particles evaporate first due to the difference in boiling points between water and oil, causing a microexplosion. Under any atmospheric conditions (temperature, pressure), water evaporates before oil, and when water explodes in an atomized state, the oil surrounding the water particles is broken into small pieces. Therefore, if the average droplet size of the dispersed phase satisfies the above range, atomization of the oil can be promoted and the contact area between the oil and oxygen in the air can be improved.

Waste oil referred to in this specification is commonly known oil waste, and is defined in a broad sense to include all oily by-products that are disposed of as a mixture containing oil as a main ingredient or generated after manufacturing a product. In detail, the waste oil may be a waste whose main component is oil, containing an oil component of 80% by weight or more, preferably 90% by weight or more, more preferably 95% by weight or more. The physical properties of waste oil may vary depending on the type of waste oil and supply route, but for example, the general density of waste oil may be 0.83 to 0.99, specifically 0.87 to 0.95 g/ml, and the general low calorific value of waste oil may be 7,000. It may be from 9,000 kcal/kg, specifically 8,000 to 8,500 kcal/kg. Examples of specific types of waste oil include waste lubricating oil; Fuel oils such as heavy oil, diesel, gasoline, and by-product fuel oil; Industrial oil waste such as waste bunker C oil (waste heavy oil); Waste cooking oils such as soybean oil, corn oil, castor oil, cottonseed oil, palm oil, tung oil, and fish oil; etc. can be mentioned. However, this is an example to aid understanding, and of course, various other types of waste oil can be used.

The fuel composition according to the present invention and the recycled emulsion-type fuel oil using waste oil containing the same contain 0.5% by weight or less of sulfur, 100 mg/kg or less of lead-containing components, 1 mg/kg or less of cadmium-containing components, and 1 mg/kg or less of arsenic-containing components. 2 mg/kg or less, chromium-containing ingredients may be 50 mg/kg or less, mercury-containing ingredients may be 1.5 mg/kg or less, and chlorine-containing ingredients may be 2,000 mg/kg or less.

The recycled fuel composition using waste oil according to the present invention, that is, emulsion-type fuel oil, can maintain almost its initial emulsion state without oil-water separation even when stored for a long period of time. Specifically, when the emulsion-type fuel oil according to the present invention is left in a non-vibrating environment at 25°C and 1 atm for 20 days, the change in emulsion particle size is less than 10%, showing excellent long-term stability.

As such, the fuel composition according to the present invention has a high calorific value, excellent combustion activity, and excellent long-term storage stability without deposits or layer separation, which has the effect of continuously maintaining excellent initial combustion characteristics.

The fuel composition according to the present invention may be used for purposes within the scope of use prescribed by law, such as transportation fuel, heating fuel, industrial fuel, auxiliary fuel in a kiln, high-temperature incineration in an incinerator, and waste gas. It can be used for animal funeral purposes, etc.

The fuel composition according to the present invention may leave incineration residues after combustion, and the incineration residues may contain alumina, silica, calcium, etc., so they can be reused as cement raw materials.

Hereinafter, the method for producing the fuel composition according to the present invention will be described.

The method for producing the fuel composition according to the present invention may use various known means for mixing the above-mentioned components, preferably comprising the steps of a) removing foreign substances in waste oil and b) mixing the waste oil with the above-mentioned components. may include.

Step a) is a step of removing foreign substances in waste oil supplied from various routes. Since waste oil may contain foreign substances such as dust, sludge, lime, and heavy metals, the quality of the fuel composition can be improved by removing these. As a means of removing foreign substances, various known methods can be applied. For example, a method of removing foreign substances by passing waste oil through a filter such as a mesh net, a centrifugation method, etc. may be used. When using a filter method, large solid foreign substances can be easily removed, and when using a centrifugation method, impurities with high density can be removed.

In the method for producing a fuel composition according to an example of the present invention, a process for removing moisture in waste oil may be further performed between steps a) and b). Since the moisture in the waste oil varies depending on the supplied waste oil, it may be desirable to first remove the moisture in the waste oil and then prepare the fuel composition according to the present invention through a process of mixing the waste oil and the fuel additive components in step b). . A means of removing moisture in waste oil may be performed through various methods, for example, heat treatment at 100 to 150°C, specifically 110 to 130°C.

The method for producing a fuel composition according to an example of the present invention may further include a process for removing air pollutants that may cause environmental pollution, which may be performed before step a); Between steps a) and b); or after step b). Preferably, if the removal process is performed between steps a) and steps b), the process efficiency and removal efficiency of air pollutants may be improved.

The method for producing a fuel composition according to an example of the present invention may further include c) removing secondary foreign substances in the fuel composition. After foreign substances in the waste oil are primarily removed in step a), a process of secondarily removing foreign substances in the fuel composition in which waste oil and fuel components are mixed may be performed in step b).

The fuel composition according to the present invention can be burned and used in various ways. For example, when combusted by spraying with a nozzle, the water particles in the fuel composition rapidly expand due to high heat, causing a microexplosion, and the surrounding oil particles are sprayed more finely. By doing this, complete combustion can be promoted by increasing the contact area with oxygen in the flame.

Hereinafter, the present invention will be described in detail through examples and comparative examples. However, these are intended to illustrate the present invention in more detail, and the scope of the present invention is not limited to the following examples.

After adding hydrogen peroxide, an inorganic emulsifier prepared by the following method, and an organic emulsifier (polyoxyethylene nonylphenyl ether) (NP-5, Green Chemical) to the waste oil to achieve the composition ratio shown in Table 1 below, homogenizer and ultrasonic waves were used. A fuel composition was prepared by mixing to sufficiently emulsify using an ultrasonic generator.

The inorganic emulsifier was prepared by the following method. Fine powder was prepared by grinding calcium carbonate (CaCO ₃ ) to an average particle diameter of 250 nm and an average specific surface area of 49.4 m ² /g, and stearic acid was added to the surface of the fine powder in a wet process using a stud mill and mixer. An inorganic emulsifier was prepared by coating in the same manner as above. Specifically, stearic acid was melted in an environment maintained at 100°C, then sprayed on the entire surface of the fine powder and dried sufficiently to prepare an inorganic emulsifier that was calcium carbonate fine powder surface-modified with stearic acid.

As shown in Table 1 below, a fuel composition was prepared in the same manner as Example 1, except that the hydrogen peroxide concentration of the hydrogen peroxide solution was changed (63% → 70%).

As shown in Table 1 below, a fuel composition was prepared in the same manner as in Example 1, except that the powder type of the inorganic emulsifier was different (CaCO ₃ → MgO), that is, magnesium oxide surface-modified with stearic acid was used as the inorganic emulsifier. did.

As shown in Table 1 below, a fuel composition was prepared in the same manner as in Example 2, except that Fucoidan (Fucoidan from Undaria pinnatifida, Sigma-Aldrich), a sulfated polysaccharide derived from brown algae, was further added to the waste oil as an activator. At this time, the content of the organic emulsifier used was reduced by the amount of the activator used.

[Comparative Example 1]

As shown in Table 1 below, a fuel composition containing 100% waste oil was prepared as a control.

[Comparative Example 2]

A fuel composition was prepared in the same manner as Example 1, except that water was used instead of hydrogen peroxide to achieve the composition ratio shown in Table 1 below. At this time, the amount of hydrogen peroxide not used was replaced with water.

[Experimental Example 1] Measurement of calorific value and combustion efficiency

The fuel compositions of Examples and Comparative Examples were left in a non-vibrating environment at room temperature (25°C) and normal pressure (1 atm) for 20 days, then each was put into a cylindrical fuel tank in the same weight, and the calorific value and combustion efficiency were measured under the same conditions. . At this time, the total calorific value (error range: ± 0.5) was measured using the KSM 2057 method, and combustion efficiency was measured according to Equation 1 below using an exhaust gas analyzer (Green Line MK2). And the results are listed in Table 1 below.

[Equation 1]

(η _c : combustion efficiency, Q _r : heat of combustion, H _u : calorific value)

[Experimental Example 2] Numerical size evaluation

The fuel compositions prepared in Examples and Comparative Examples were left in a vibration-controlled environment at room temperature and pressure for 1 day, and then the droplet size of the fuel composition was evaluated.

Specifically, to measure the droplet size of the dispersed phase in the continuous phase of a fuel composition left in a vibration-controlled environment for 1 day at room temperature (25°C) and normal pressure (1 atm), the fuel composition was used as a sample and placed on a glass slide. After thin application, images were taken at 50x magnification. Then, the micro-scale image taken at the same magnification was used as the standard dimension, and the size of droplets (SMD) was measured through the image and expressed using SMD (Sauter's mean diameter) expressed in Equation 2 below.

[Equation 2]

(Ni: number of particles, Di: particle diameter (㎛))

Water-in-oil (W/O) emulsion particles combine with each other and increase in size, resulting in agglomeration. In this case, the emulsion state is not maintained for a long time and a problem occurs in which the oil, which is a continuous phase, and water, which is a dispersed phase, separate, causing agglomeration phenomenon. is the biggest threat to the stability of emulsion fuel. Therefore, the smaller the SMD, the higher the long-term storage stability of the fuel composition.

[Experimental Example 3] Long-term stability evaluation

The initial emulsion particle size of the fuel composition prepared in Examples and Comparative Examples was measured, and the change in emulsion particle size was less than 10% after being left in a non-vibrating environment at room temperature (25°C) and normal pressure (1 atm) for 20 days. Cases were evaluated as 'high', cases of more than 10% and less than 15% were evaluated as 'medium', and cases of more than 15% were evaluated as 'low'.

Composition cost (kg) Example Comparative example One 2 3 4 One 2 waste oil 68.0 68.0 68.0 68.0 100.0 68.0 hydrogen peroxide H ₂ O ₂ 19.0 21.0 21.0 21.0 - - water 11.0 9.0 9.0 9.0 - 30.0 inorganic emulsifier CaCO ₃ 1.0 1.0 - 1.0 - 1.0 MgO - - 1.0 - - - organic emulsifier NP-5 1.0 1.0 1.0 0.5 1.0 activator Fucoidan - - - 0.5 - - Low calorific value (kcal/kg) 5,650 5,870 5,940 6,190 8,300 5,120 Combustion efficiency (%) 90.1 90.3 90.5 91.6 87.3 88.7 Drop size (㎛) 5.8 5.8 5.3 3.9 - 6.9 long-term stability under under middle award - under

As a result, when comparing Comparative Example 1 and Comparative Example 2 in Table 1 below, it can be seen that combustion efficiency is increased by mixing water into waste oil.

Additionally, comparing Example 1 and Comparative Example 2, combustion efficiency and calorific value were significantly improved by mixing hydrogen peroxide with waste oil and water. In particular, comparing Example 1 and Example 2, when the hydrogen peroxide concentration of the hydrogen peroxide water was 68% by weight or more, the calorific value further increased. This result shows that hydrogen peroxide not only acts as an oxidizing agent, but also participates in an exothermic reaction in which hydrogen peroxide decomposes above a certain concentration. It is believed that the thermal energy generated is not all absorbed as the latent heat of evaporation of water and contributes to the increase in calorific value along with waste oil.

Furthermore, comparing Example 2 and Example 3, when magnesium oxide was used as the powder type of the inorganic emulsifier, combustion efficiency was higher, calorific value was further improved, and long-term stability was also improved compared to when calcium carbonate was used. From this, it can be seen that the magnesium compound has the effect of suppressing the decomposition of hydrogen peroxide in a low-temperature environment and having no negative effect on the explosive decomposition of hydrogen peroxide in a high-temperature environment (combustion).

In addition, in Example 4, in which more activators were mixed compared to Example 3, the size of the dispersed phase droplets was smaller, the calorific value and combustion efficiency were increased, and in particular, long-term stability was significantly improved. Therefore, it can be seen that Fucoidan, an activator, not only helps emulsify the oil phase (waste oil) and the water phase (hydrogen peroxide), but also suppresses the low-temperature decomposition characteristics of hydrogen peroxide by acting as a radical scavenger.

Claims (6)

53 to 80% by weight of waste oil; 17 to 45% by weight of hydrogen peroxide water containing at least 68% by weight of hydrogen peroxide; And 0.1 to 3% by weight of an inorganic emulsifier;
The inorganic emulsifier has a Pickering emulsion-based surface activity ability and includes an inorganic powder containing any one or two or more selected from oxides, carbonates, and hydroxides of Group 1 or Group 2 metals, and the surface of the inorganic powder A recycled fuel composition using waste oil in which a lipophilic organic compound is grafted or physically adsorbed and the surface is modified to be hydrophobic. delete delete delete According to paragraph 1,
A recycled fuel composition using waste oil, further comprising an activator containing sulfated polysaccharide derived from brown algae. A recycled emulsion-type fuel oil using waste oil, comprising the recycled fuel composition using the waste oil of claim 1 or 5,
The emulsion type fuel oil,
An aqueous dispersed phase containing hydrogen peroxide of the fuel composition; and
It includes a continuous oil phase containing waste oil of the fuel composition,
Recycled emulsion-type fuel oil using waste oil, wherein the average droplet size of the dispersed phase is 1 to 10 ㎛.