WO2007004789A1

WO2007004789A1 - Fuel composition containing bioethanol and biodiesel for internal combustion engine

Info

Publication number: WO2007004789A1
Application number: PCT/KR2006/002222
Authority: WO
Inventors: Yong Man Lee
Original assignee: Pure Life Co Ltd; Yong Man Lee
Priority date: 2005-07-01
Filing date: 2006-06-09
Publication date: 2007-01-11
Also published as: EP1904610A1

Abstract

Disclosed herein is a fuel composition for internal combustion engines, which comprises: a) 1-45 wt % of toluene; b) 1-45 wt % of xylene; c) 1-85 wt % of bioethanol, ethanol or a mixture thereof ; d) 10-69 wt % of industrial gasoline; e) 1-19 wt % of aromatic solvent; f) 1-13 wt % of isopropanol; and g) 1- 12 wt % of isobutanol. Also, the fuel composition can additionally contain isopentane to maximize the heating value of the composition upon burning, and can additionally contain, as an additive, a corrosion inhibitor which is conventionally added to liquid fuel in order to prevent the corrosion of internal combustion engines. The disclosed fuel shows a remarkable reduction in air pollution, compared to the existing gasoline, and, at the same time, has improved power performance, and thus is useful as alternative fuel having economic efficiency.

Description

[DESCRIPTION] [invention Title]

Fuel Composition Containing Bioethanol and Biodiesel for Internal Combustion Engine

[Technical Field]

The present invention relates to a fuel composition for internal combustion engines, and more particularly to a fuel composition as alternative fuel for internal combustion engines, which can be used not only in a gasoline engine that uses gasoline as fuel, but also in a diesel engine that uses light oil as fuel.

[Background Art] As the problem of exhaustion of petroleum resources has arisen due to the 1970s oil shock, and the problem of environmental pollution by fossil fuel has been raised as a worldwide issue, it is not too much to say that the world is now in a war with energy and environment. Particularly, countries having no petroleum resources, such as Korea, should take interest in the development of alternative energy, and should hasten the development of alternative fuel in order to cope with internal environmental regulation (the Kyoto Protocol) which is strengthened daily. Nevertheless, gasoline is widely used as fuel for internal combustion engines, and thus acts as the main cause of air pollution, because, when burned, it generates carbon oxide (CO_x) , nitrogen oxide (NO_x) and sulfur oxide (SO_x) , which are discharged into the air. To overcome the above problem, biomass alternative fuel receives attention. As a candidate group of alternative fuel, methanol, which can be prepared from natural gas, coal, wood and the like, is suitable for high-compression-ratio engines due to a high octane number of about 101.5. When it is used in diesel engines, it does not generate soot during burning, and is free of sulfur, thus contributing to a great reduction in the generation of nitrogen oxide (NOx) and sulfur oxide (SOx) . However, when bioethanol or 100% methanol alone is used in the existing gasoline engines, its heating value per unit volume is only about half that of gasoline, and thus requires a fuel tank capacity of two times that of gasoline at the same traveling distance. Also, when it is applied for diesel engines, it requires a separate ignition device due to low cetane value. Also, it can corrode gasoline engines. Thus, it is difficult to apply said bioethanol or methanol, as long as the structure of the existing internal combustion engines is changed .

According to the study of West Virginia University, USA, analysis results for methanol, bioethanol and biodiesel as alternative fuel candidate substances for internal combustion engines revealed that methanol discharged the smallest amount of nitrogen oxide, and thus received the highest evaluation score in terms of the prevention of environmental pollution. The second rank was bioethanol, followed by biodiesel. Although methanol provides the advantage of solving an environmental problem, it shows the above-mentioned shortcomings in use as fuel for internal combustion engines. For this reason, interest in ethanol, particularly bioethanol, is being raised. Actually, synthetic ethanol is frequently used in industrial applications, and bioethanol, which is alcoholic fuel extractable from plants, is similar to methanol and has reduced toxicity and exhaust gases.

Bioethanol-containing internal combustion engine fuel oil such as the inventive composition has an advantage in that it can be filled without changing the existing automobile internal combustion engine. Currently, in USA, Brazil, etc., a mixture of gasoline and bioethanol, called "gasohol" , is used as fuel. However, it has poor ignition quality, and thus is hardly used in the winter season, and bioethanol extracted from plants has a limited use in areas in which plant resources are not sufficiently secured.

Bioethanol is obtained by converting carbohydrate contained in biomass into sugar and then fermenting the sugar. When a sugar cane or sugar beet is used as a sugar source, bioethanol is obtained by extracting sugar directly therefrom and subjecting the extracted sugar to alcohol fermentation. Also, biodiesel is produced through a process in which oils organically extracted from naturally occurring plants (rape seeds, sunflower seeds, soybeans, etc.) are combined with alcohol in the presence of a catalyst to form ethyl ester or methyl ester.

Biodiesel shows a sufficient possibility as alternative fuel in terms of eco- friendly properties, and is actually used in advanced countries, including Europe. However, it is also not used as a complete fuel product, but rather is used as an additive in diesel fuel or is used in a mixture with light oil in automobiles. Thus, it is considered that the fuel dependence of diesel engines on light oil in the prior art is still high. [Disclosure] [Technical Problem]

The present invention has been made to solve the above- described problems occurring in the prior art, and it is an object of the present invention to provide an internal combustion engine fuel composition as alternative fuel which can be used not only in a gasoline engine that uses gasoline as fuel, but also in a diesel engine that uses light oil as fuel. More specifically, the present invention provides a fuel composition for internal combustion engines, which comprises bioethanol, ethanol, methanol, toluene, xylene, aromatic solvent, isopropanol, isobutanol and industrial gasoline.

Another object of the present invention is to provide a novel fuel composition, which has increased octane number by including an ethanol component, and contains a reduced amount of harmful exhaust substances, leading to a reduction in environmental pollutants.

Still another object of the present invention is to provide a novel fuel composition, which employs bioethanol as one component thereof, which can also serve as an octane enhancer so as to minimize the use of the octane improver without the use of a separate octane enhancer, thus minimizing environmental pollution. More specifically, the present invention aims to provide a fuel composition which can substitute for an existing substance (MTBE) which has been recognized as a pollutant of underground water or soil and also as an environmental pollutant due to poor biodegradability.

Still another object of the present invention is to provide a fuel composition for internal combustion engines, which can additionally contain isopentane to maximize the heating value of the composition upon burning, and can additionally contain, as an additive, a corrosion inhibitor which is conventionally added to liquid fuel in order to prevent the corrosion of internal combustion engines. Yet another object of the present invention is to provide a fuel composition containing biodiesel applicable to diesel engines.

Further another object of the present invention is to provide a universal fuel composition which can be used in all gasoline engines and diesel engines. [Technical Solution]

To achieve the above objects, in one embodiment, the present invention provides a fuel composition for internal combustion engines, which contains ethanol . In a preferred embodiment, the present invention provides a novel fuel composition for internal combustion engines, which contains bioethanol that has a high effect of reducing harmful substance emission and can increase engine performance.

In another embodiment, the present invention provides a fuel composition for internal combustion engines, which comprises: a) 1-45 wt% of toluene; b) 1-45 wt% of xylene; c) 1-85 wt% of ethanol, bioethanol or a mixture thereof; and d) 5-69 wt% of industrial gasoline.

In still another embodiment, the present invention provides a fuel composition for internal combustion engines, which comprises, in addition to the components a) to d) of said fuel composition, at least one component selected from among e) 1-19 wt% of aromatic solvent, f) 1-17 wt% of isopropanol, and g) 1-18 wt% of isobutanol. Hereinafter, each of the components of the inventive fuel composition will be described in further detail.

The toluene and xylene components in the inventive composition are used to enhance the power of engines, and the xylene component is not specifically limited, as long as it is any one of conventional isomers or mixtures thereof .

The component c) in the inventive composition, i.e., ethanol, bioethanol or a mixture thereof, is used to achieve high octane number and high compression ratio in the inventive composition, and to completely solve an environmental pollution problem and corrosion problem resulting from formaldehyde production caused by the single use of methanol, such that the fuel composition shows very excellent effects.

Industrial gasoline (KSM2611) as the component d) in the inventive composition is a fraction separated from crude petroleum, and examples thereof, which can be used in the present invention, include solvent No. 1 (benzine), solvent No. 2 (rubber solvent) , solvent No. 3 (solvent naphtha) , solvent No. 4 (mineral spirit), and solvent No. 5 (cleaning solvent) which are standardized in Korean Industrial Standard (KS) . Among them, the use of solvent No. 1 (benzine) can provide a fuel composition which shows the most excellent effect on smoke reduction and did not generate soot. Examples of the industrial gasoline include CAS#8032-32-4 (benzine) , CAS#8052- 41-3 (stoddard solvent) , CAS#8030-31-7 (aromatic solvent) , which are internationally used under the following general common names and trade names: canadol, isoparaffinic hydrocarbon, ligroin, mineral spirits, naphtha ligroin, refined solvent naphtha, VM&P naphtha, vanish marker's naphtha, naphtha solvent, naphtha stoddard solvent, White spirits, stoddard solvent naphtha, stoddard solvent organic solvent, enamel thinner, mineral thinner, rubber solvent (naphtha) , Vasol, and White spirits.

Examples of aromatic solvent as the component e) in the inventive composition include C8-C14 alkyl-substituted benzene derivatives and mixtures thereof, which are substantially free of or contain xylene and toluene in an amount of less than 3 wt% based on the total weight thereof . It is used to improve fuel combustion ratio in the inventive composition. Said aromatic hydrocarbon is a mixture of two or more selected from the group consisting of ethyl benzene, 1-methyl-3 -ethyl benzene, 1 , 3 , 5-trimethyl benzene, 1, 2, 4-trimethyl benzene, 1,2,3- trimethyl benzene, isopropyl benzene, propyl benzene, cumene, and 1-ethyl-2-methyl benzene. Specific examples thereof include: Aromatic- 100 (classified as CAS#64742-95-6 ; Exxon Mobile Corp.), Hi-Sol 10 (Ashland Inc.), Kocosol-100 (SK), Kocosol-150 (CAS#64742-94-5; SK), polyethylbenzene, Heavy aromatic naphtha, high-flash aromatic, and Shellsol R.

Hereinafter, the role and content of each component of the inventive composition will be described in further detail. Toluene as the component a) and xylene as the component b) serve to increase the explosive power of the fuel composition, and if they are used in amounts out of the above- specified ranges, it will be difficult to maintain a significant degree of explosive powder. The xylene component generally refers to a xylene component consisting of a single xylene isomer or a mixture of xylene isomers .

Also, if the component c) consisting of ethanol, bioethanol or a mixture thereof, is used in an amount of less than 1 wt% in the fuel composition, high octane number and high-compression ratio in internal combustion engines cannot be obtained. Also, industrial gasoline as the component d) enables the components of the fuel composition to be smoothly- blended with each other so as to prevent impurities from clogging nozzles attached to internal combustion engines, and also provides an improvement in engine starting ability.

Aromatic solvent as the component e) , which can be selectively used to fuel oil having the desired physical properties, serves to improve ignition quality. The content of the component e) in the composition is less than 1 wt%, it will be difficult to expect high ignition quality as desired, and if it exceeds 19 wt%, the heating value of the composition upon burning will be limited. Isopropanol as the component f) serves to reduce the interfacial tension between hydrophilic ethanol as a main component of the inventive composition and the hydropholic aromatic compound so as to enable the components of the composition to be well mixed with each other. Also, isobutanol as the component g) is used to improve low- temperature starting ability which is the shortcoming of ethanol. If the inventive composition contains the component g) in the above-specified content range, it can maintain the most excellent low-temperature starting ability, so that it can be used as internal combustion engine fuel even in the cold latitudes.

In order to maximize the heating value of the inventive fuel composition upon burning, the inventive composition may optionally contain 0.5-10 wt%, based on the total weight of the composition, of isopentanol, and/or a corrosion inhibitor which is added to liquid fuel in order to prevent the corrosion of internal combustion engines. The corrosion inhibitor can be suitably selected for use in the inventive composition, since a variety of the corrosion inhibitors (e.g., amine-based compounds such as aminophenol, poly (hydroxycarboxylic acid) amide or ester derivatives) are suggested in published documents. However, the content of the corrosion inhibitor in the inventive composition is preferably 0.05-5 wt%. If the content of the corrosion inhibitor is less than 0.05 wt%, it cannot sufficiently achieve the desired corrosion prevention effect, and if it is more than 5 wt%, it will cause problems with respect to the economy and effect of alternative fuel containing it.

In the present invention, if bioethanol is used, the bioethanol component itself can serve as an octane enhancer, and thus, high octane number can be obtained without a need to use MTBE or ETBE which has been classified as a pollutant. However, it is also within the scope of the present invention to use a small amount of MTBE or ETBE in the composition in order to slightly increase octane number. In this case, it is preferable in view of economic efficiency to use the octane enhancer in an amount of 0.1-5 wt% based on the total weight of the composition. Also, it is possible to use methanol in an amount of 1-85 wt% based on the total weight of the component c) consisting of ethanol, bioethanol or a mixture thereof. However, if methanol is used alone, it can cause problems such as formaldehyde production and engine corrosion and also can result in a reduction in engine performance compared to the use of ethanol. For this reason, methanol is preferably used in a mixture with ethanol, bioethanol or a mixture thereof in view of engine performance improvement .

As ethanol which is contained in the inventive fuel composition for internal combustion engine, synthetic ethanol having a purity of 95% can be used. Although it is not to say that an increase in ethanol purity can minimize problems such as incomplete combustion and the occurrence of engine corrosion, anhydrous ethanol is expensive, and thus has an effect on the economy of fuel . To overcome the shortcoming of synthetic ethanol, bioethanol extracted from nature can also be used. In other words, it is possible to use bioethanol which is obtained either by converting carbohydrates (corn, artichoke, etc.) contained in biomass into sugar and subjecting the sugar to alcohol fermentation, or by extracting sugar from sugar cane or sugar beet and fermenting the extracted sugar. If bioethanol is used in the inventive composition, there will be an additional advantage in that octane number is sufficiently increased without a need to use an octane enhancer such as MTBE. Thus, bioethanol does not cause environmental contamination such as water and soil contamination upon leakage, and is easily biodegraded, and thus it shows very excellent effects in terms of environmental protection and an improvement in the physical properties of the fuel composition.

In another embodiment of the present invention, the inventive composition may additionally contain biodiesel in an amount of 0.01-85 wt% based on the total weight of the composition. If it is used in an amount of 0.01-85 wt% in the inventive composition, it makes the lubricating action in gasoline engines smooth so as to exhibit effects of improving fuel consumption ratio and extending the life cycle of the engines, and thus shows a more excellent effect compared to the use of existing gasoline. In other words, it is possible to use biodiesel produced in a conventional biodiesel production process, in which oils organically extracted from naturally occurring plants (rape seeds, sunflower seeds, soybeans, etc.) are combined with alcohol in the presence of a catalyst to form ethyl ester or methyl ester. If the content of biodiesel in the inventive composition exceeds 85 wt%, it can undesirably reduce the coagulation temperature of the composition to clog an automobile oil filter, leading to a reduction in engine power.

The inventive fuel composition for internal combustion engines can be immediately used as alternative fuel for internal combustion engines. Also, the inventive composition may be used in a mixture with gasoline or diesel oil. This construction is another subject of the present invention.

The inventive fuel composition for internal combustion engines is a novel biofuel for internal combustion engines, which has reduced air pollutant emission and can solve exhaust gas reduction and environmental pollution issues (underground water and soil contamination) , particularly when it contains bioethanol . Also, the inventive composition has an advantage of substituting for an octane enhancer (typically MTBE) . Thus, another aspect of the present invention relates to a novel method of reducing waste emission from internal combustion engines, as well as an octane enhancer. The inventive fuel composition for internal combustion engines is used as internal combustion engine fuel alone or in a mixture with already known fuel.

Also, the inventive fuel composition can be used as gasoline alternative fuel or an additive.

The present invention will be described in further detail with reference to examples. It is to be understood, however, that these examples are not to be construed to limit the scope of the present invention.

The inventive fuel composition for internal combustion engines was evaluated according to European test method ECE15+EUDC which is the same method as described in Korean Patent Registration No. 10-0525362. As comparative fuel, unleaded gasoline having an octane number of 93 was used. Using fuel compositions prepared in Examples 1 to 5 below, Vehicle Volkswagen Jetta (FV7160Cix) (see Table 1) traveled 200 km, and then measurements were performed in accordance with the following standards: GB18352.2-2001 (Limits and measurement methods for pollutant emissions) , GB/T3845-93

(Limits and measurement methods for exhaust pollutants from vehicles) , GB/T12543-90 (measurement methods for acceleration performance of vehicles) , GB1495-2002 (Limits and measurement methods for noise emitted by accelerating motor vehicles) . In other words, after the Jetta vehicle injected with each of the fuel composition traveled 200 km, exhaust gas emission test during idling was carried out two times, the ECE15+EUDC test (measurement of pollutant emission) and fuel economy were measured one time, and power performance and noise were measured one time.

[Table 1] Specification of test vehicle

[Mode for Invention]

Example 1

The components below were mixed with each other to obtain the inventive fuel composition for internal combustion engines and tested for performance. The test results are shown in Tables below. It could be known that the inventive composition had a high octane number of 96, even though it did not contain a separate octane enhancer.

1) 4 wt% of Aromatic-100 as aromatic solvent 2) 16 wt% of toluene

3) 10 wt% of xylene

4) 13 wt% of bioethanol

5) 4 wt% of isopropanol

6) 2 wt% of isobutanol 7) 51 wt% of benzine as industrial gasoline

Example 2

The procedure of Example 1 was repeated, except that mixed fuel consisting of 10 wt% of the fuel composition prepared in Example 1 and 90 wt% of unleaded gasoline having an octane number of 93 was prepared and tested for performance. The test results are shown in Tables below.

Example 3 The procedure of Example 1 was repeated, except that mixed fuel consisting of 40 wt% of the fuel composition prepared in Example 1 and 60 wt% of unleaded gasoline having an octane number of 93 was prepared and tested for performance. The test results are shown in Tables below. Comparative Example 1

The procedure of Example 1 was repeated, except that unloaded gasoline having an octane number of 93 was used in place of the fuel composition of Example 1. The test results are shown in Tables below.

Comparative Example 1

The procedure of Example 1 was repeated, except that methanol was used in place of bioethanol. The test results are shown in Tables below.

Example 4

The procedure of Example 1 was repeated, except that 14 wt% of toluene, 48 wt% of industrial gasoline and 5 wt% of biodiesel were used. The test results are shown in Tables below.

Example 5

The procedure of Example 1 was repeated, except that 48 wt% of industrial gasoline and 3 wt% of MTBE as an octane enhancer were used. As a result, it could be found that the inventive fuel composition had a very excellent effect with respect to output and engine starting ability. Table 2: Results of exhaust gas emission test during idling of JETTA (VOLKSVAGEN) vehicle

As shown in Table 2 above, the results of exhaust gas emission measurement conducted according to the GB18352.2-2001 test method showed that, in Examples 1-5 and Comparative Examples 1 and 2, exhaust gas emissions during engine idling and after traveled 200 km were not increased, suggesting that these compositions all had no pollutant in exhaust gas during idling.

Table 3: Test results for pollutant emission and fuel economy in JETTA (VOLKSVAGEN) vehicle

As shown in Table 3, the inventive fuel compositions showed a remarkable reduction in hydrocarbon (HC) , carbon monoxide (CO) and NOx, compared to Comparative Example 1 (methanol) and Comparative Example 2 (unleaded gasoline having an octane number of 93) . Particularly, Example 1 using bioethanol alone and Example 4 using the bioethanol/biodiesel mixture showed a reduction of more than 25% in the emission of exhaust pollutants. Also, regarding fuel consumption, Example 1 showed a reduction of more than 5% compared to the use of methanol, and a reduction of more than 2% compared to the use of unleaded gasoline having an octane number of 93.

Table 4 : Power performance test results for JETTA (VOLKSVAGEN) vehicle (unit: sec)

As shown in Table 4 above, with respect to the time taken to shift gears to speed 4 and speed 5 after traveling 200 km, Example 1 using bioethanol alone and Example 4 using the bioethanol/biomethanol mixture showed running acceleration faster than Comparative Example 2 using methanol and Comparative Example 1 using general gasoline having an octane number of 93. Table 5 : Measurement of noise during acceleration of vehicle

(1) Test results for Comparative Example 1 after traveling 200 km

(2) Test results for Example 1 after traveling 200 km

(3) Test results for Example 2 after traveling 200 km

(4) Test results for Example 3 after traveling 200 km

As can be seen in Table 5 above, the inventive fuel composition also showed an excellent noise reduction effect, [industrial Applicability]

As described above, the inventive composition for internal combustion engines is advantageous in terms of environmental protection, because, when used as internal combustion engine fuel, it shows a remarkable reduction in the production and emission of air pollutants, compared to the existing gasoline fuel and diesel fuel. Also, the inventive fuel composition is advantageous in terms of energy, because it shows excellent power performance compared to the existing gasoline fuel and diesel fuel. In addition, the inventive fuel composition shows reduced noise.

Claims

[CLAIMS]

[Claim l]

A fuel composition for internal combustion engines, which comprises : a) 1-45 wt% of toluene; b) 1-45 wt% of xylene; c) 1-85 wt% of ethanol, bioethanol or a mixture thereof; and d) 10-69 wt% of industrial gasoline.

[Claim 2)

The fuel composition of Claim 1, which further comprises at least one selected from among 1-19 wt% of aromatic solvent, 1-13 wt% of isopropanol, and 1-12 wt% of isobutanol.

[Claim 3]

The fuel composition of Claim 1, which further comprises at least one selected from among 0.5-10 wt% of isopentane, 0.05-5 wt% of a corrosion inhibitor, and 0.01-85 wt% of biodiesel.

[Claim 4]

The fuel composition of Claim 2, which further comprises at least one selected from among 0.

5-10 wt% of isopentane, 0.05-5 wt% of a corrosion inhibitor, and 0.01-85 wt% of biodiesel.

[Claim 5j

The fuel composition of any one of Claims 1 to 4 , wherein the component c) is a mixture with methanol.

[Claim 6]

The fuel composition of Claim 2 or 4 , wherein the aromatic solvent is a mixture of two or more selected from the group consisting of ethyl benzene, 1-methyl-3 -ethyl benzene, 1, 3, 5-trimethyl benzene, 1, 2, 4-trimethyl benzene, 1,2,3- trimethyl benzene, isopropyl benzene, propyl benzene, cumene, and 1-ethyl-2 -methyl benzene.

[Claim 7]

The fuel composition of any one of Claims 1 to 4, wherein the industrial gasoline is selected from the group consisting of benzine, stoddard solvent, canadol, isoparaffinic hydrocarbon, ligroin, mineral spirits, naphtha ligroin, refined solvent naphtha, VM&P naphtha, vanish marker's naphtha, naphtha solvent, naphtha stoddard solvent, White spirits, stoddard solvent naphtha, stoddard solvent organic solvent, enamel thinner, mineral thinner, rubber solvent, and Vasol .

[Claim 8]

The fuel composition of Claim 6, wherein the industrial gasoline is selected from the group consisting of benzine, stoddard solvent, canadol, isoparaffinic hydrocarbon, ligroin, mineral spirits, naphtha ligroin, refined solvent naphtha, VM&P naphtha, vanish marker's naphtha, naphtha solvent, naphtha stoddard solvent, White spirits, stoddard solvent naphtha, stoddard solvent organic solvent, enamel thinner, mineral thinner, rubber solvent, and Vasol. [Claim 9] The fuel composition of any one of Claims 1 to 4 , which further comprises octane enhancer MTBE or ETBE in an amount of 0.1-5 wt%.

[Claim lθ]

Alternative fuel for internal combustion engines, in which a composition set forth in any one of Claims 1 to 4 is used alone or in a mixture with known internal combustion engine fuel .