WO2003002694A1

WO2003002694A1 - Low-pollution synthetic liquid fuel for internal combustion engine

Info

Publication number: WO2003002694A1
Application number: PCT/JP2001/005730
Authority: WO
Inventors: Akihiro Azuma
Original assignee: Akihiro Azuma
Priority date: 2001-06-27
Filing date: 2001-07-02
Publication date: 2003-01-09
Also published as: JPWO2003002694A1

Abstract

A low-pollution synthetic liquid fuel for internal combustion engines which comprises one or more saturated or unsaturated hydrocarbons having up to 12 carbon atoms, one or more alcohols, and one or more ethers, wherein the ethers comprise an ether having at least two ether bonds per molecule. In the fuel, the hydrocarbon ingredient is prevented from separating from the alcohol ingredient even when a relatively long-chain ether is employed.

Description

Description Low-pollution synthetic liquid fuel for internal combustion engines

Technical field

The present invention provides the same or higher efficiency and output as conventional gasoline without changing the structure or material of the existing gasoline internal combustion engine, and provides carbon monoxide (CO) in exhaust gas. And low-pollution synthetic liquid fuels for internal combustion engines whose hydrocarbon (HC) concentration is significantly reduced compared to conventional gasoline. Background art

As part of our efforts to address environmental issues in recent years, the issue of air pollution due to vehicle emissions has become even more important. Carbon monoxide (CO) and hydrocarbons in these vehicle emissions have become increasingly important. As a fuel for an internal combustion engine that can be used as a substitute for conventional gasoline by significantly lowering the concentration of (HC), alcohol and ether are mixed with light naphtha as previously filed by the present inventors. The product has been commercialized and already sold.

As described above, the synthetic liquid fuel obtained by mixing alcohol and ether with these light naphthas, together with carbon monoxide (CO) and hydrocarbons (HC), has a higher sulfur content in alcohols than in light naphthas. Although it is preferable because it can reduce SO x etc. because it has a very small amount of components, it is preferable because the fuel temperature is higher than that of conventional gasoline fuel. There was a problem that the amount of emissions from gasoline fuel might be about three times depending on the content of blending.

Therefore, as a result of studying various formulations in order to reduce the emission of NOx, the emission of N 低下 x was reduced when the alkyl ether group of the ether molecule used was relatively long as the ether to be added. However, since these alkyl groups have relatively low-chain ethers, the polarity of these ethers becomes lower, so that by adding these ethers, separation of the light naphtha and alcohol can be prevented. Summer However, when water flows into the fuel due to water absorption, etc., when these alkyl groups use relatively long-chain ethers, light naphtha and alcohol are separated, and good fuel characteristics are obtained. There was a problem of disappearing.

Accordingly, the present invention has been made in view of the above problems, and a low-pollution synthetic liquid fuel for an internal combustion engine which does not cause separation of light naphtha and alcohol even when relatively long-chain ether is used. It is intended to provide. Disclosure of the invention

In order to achieve the above object, a low-pollution synthetic liquid fuel for an internal combustion engine according to the present invention includes a low-pollution synthetic liquid for an internal combustion engine, which contains at least a saturated or unsaturated hydrocarbon having 12 or less carbon atoms, an alcohol and an ether. A liquid fuel, wherein the ether includes an ether having at least two ether bonds in its molecule.

According to this feature, even if the alkyl group in the ether molecule has a relatively long chain by containing an ether having at least two ether bonds in the ether molecule in the ether component, the polarity of the ether is high. Since the decrease in water content is alleviated and the affinity with alcohol is not impaired, light naphtha and alcohol do not separate even if some water flows into the fuel.

In the low-pollution synthetic liquid fuel for an internal combustion engine of the present invention, the number of carbon atoms in the ether molecule having at least two ether bonds is preferably 4 or more.

In this way, by using an ether having 4 or more carbon atoms, it is possible to significantly reduce the amount of NO x emissions as compared with the conventional one.

In the low-pollution synthetic liquid fuel for an internal combustion engine of the present invention, it is preferable that the ether having at least two ether bonds is ethylene glycol dimethyl ether.

In this way, ethylene glycol dimethyl ether is suitable for use as an ether having at least two ether bonds because it is industrially manufactured in large quantities and can be obtained at low cost.

The low-pollution synthetic liquid fuel for an internal combustion engine of the present invention comprises methyl ether as the ether. It is preferably free of butyl ether (M.T.B.E.).

In this way, methyl butyl butyl ether (M.T.B.E.) has been used as an additive to gasoline fuel, but has recently caused environmental problems due to groundwater pollution and the like. Therefore, by not using these methyl tertiary butyl ethers (MTBE), it is possible to avoid environmental pollution due to the residual methyl tertiary butyl ether (MTBE).

The low-pollution synthetic liquid fuel for an internal combustion engine according to the present invention comprises: 15 to 75% by weight of aliphatic monohydric alcohol as the alcohol; and 20 to 8 of saturated or unsaturated hydrocarbon having 9 or less carbon atoms. 0% by weight, and preferably contains 5 to 20% by weight of an ether containing an ether having at least two ether bonds in the molecule.

In this way, it is possible to obtain a suitable low-pollution synthetic liquid fuel for an internal combustion engine that achieves both the calorific value (power) of the synthetic liquid fuel and low-pollution life. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a flowchart showing a method for producing a low-pollution liquid fuel for an internal combustion engine in an embodiment of the present invention.

FIG. 2 is a graph showing the relationship between the ratio of alcohol and hydrocarbon components in liquid fuel and the concentration of pollutant gas in exhaust gas.

FIG. 3 is a graph showing the relationship between the specific gravity of the obtained fuel and the fuel efficiency.

Fig. 4 is a graph showing the number of carbon atoms in the ether molecules used and the change in NOx in the exhaust gas. BEST MODE FOR CARRYING OUT THE INVENTION

For each of the above-mentioned alcohols, straight-chain hydrocarbons and ethers to be blended, the content ratio in the obtained synthetic liquid fuel, those which can be suitably used, and the reasons thereof will be described below.

First, as the alcohol, a linear or non-linear alcohol having 2 to 9 carbon atoms in the alcohol molecule can be suitably used. These alcohols have more carbon atoms than ethyl alcohol, which has 2 carbon atoms in the molecule. The use of low alcohol and the elimination of methanol, which is a highly polar alcohol with 1 carbon atom, increases the overall polarity of the resulting synthetic liquid fuel and increases the polarity of these highly polar methanol. Can be prevented from separating and swelling the fuel supply rubber pipe and the like.

Examples of these alcohols include glycols having a plurality of hydroxyl groups in the molecule, but these secondary and tertiary polyhydric alcohols are expensive and difficult to obtain. Therefore, it is preferable to use first-class alcohol.

In addition, when the number of carbon atoms in the molecular chain contained in these alcohol molecules is 10 or more, the volatility at ordinary room temperature is greatly reduced, and the combustion time in combustion tends to be short. However, since the difference with the combustion rate of hydrocarbons is likely to occur, and the fuel becomes unsuitable as a gasoline substitute fuel, the carbon number is preferably 9 or less.

Further, as these alcohols, an appropriate alcohol is selected in a range of 2 to 5 types depending on the price, availability, brand ability and the like, and the plurality of alcohols can be mixed and used. By using two or more different but not more than five different alcohols in this manner, the specific gravity of the synthetic fuel varies due to variations in the composition of the light naphtha and recycled hydrocarbons used, and the ratio of these alcohols can be adjusted appropriately. Not only can it be adjusted by changing it, but also its burning rate is slightly different for each alcohol, so by combining these alcohols, the burning rate can be adjusted to gasoline, and From the viewpoint of work when using facilities for soline, it is preferable from the viewpoint of work. From the viewpoint of price and volatility, combinations of these alcohols include ethanol, isopropyl alcohol (IPA), isobutyl alcohol (IBA), and butyl alcohol. , Pen, octanol, etc. It is preferable to use a non-linear aliphatic monohydric alcohol in particular, since the octane value of the obtained fuel can be improved, but the present invention is not limited to this.

If the ratio of these alcohols in the synthetic fuel is lower than 15% by weight, the concentration of CO and HC in the exhaust gas increases as shown in FIG. When the obtained fuel is used as a fuel for gasoline engines when the alcohol ratio exceeds about 55% by weight, the gasoline engine has a large change in acceleration (acceleration / deceleration), and the amount of fuel supplied is large. In some cases, the engine cannot keep up with the increase in engine speed, and the resulting combustion speed of the fuel tends to be in a rotation range that is not synchronized between hydrocarbons and alcohol, so that unburned fuel and burning fuel are discharged into the exhaust system. If the ratio exceeds 75% by weight, the asynchronous phenomenon of combustion may become more intense and hinder the driving. The range may be from 15 to 75% by weight, more preferably from 25 to 55% by weight.

Next, when the number of carbon atoms contained in the hydrocarbon molecule exceeds 10 as the hydrocarbon, the volatility of the hydrocarbon decreases and the igniting ability of the igniter decreases. Since the concentration of CO and HC in the solution increases, it is sufficient to use a saturated or unsaturated hydrocarbon having 9 or less carbon atoms. Among them, light naphtha, which is a mixture of linear hydrocarbons, is expensive. Can be suitably used because of its low cost.

Many of these light naphthas contain aromatic hydrocarbons such as B (benzene), T (toluene), and X (xylene), but when the concentration of these aromatic hydrocarbons is high, gasoline fuel Similarly, the concentration of CO and HC in the exhaust gas rises, and the harmful aromatic hydrocarbons such as B (benzene), T (toluene), and X (xylene) themselves are emitted into the exhaust gas. Since they may be removed, use those purified so that the content of each of these aromatic hydrocarbons such as B (benzene), T (toluene) and X (xylene) is 1% or less. Is preferred.

In addition, these light naphthas have significantly different intrinsic sulfur concentrations depending on the crude oil producing regions.However, when these sulfur concentrations are high, SOx in the exhaust gas increases, so that it is less than 0.01%. It is preferable to desulfurize so that

Along with these light naphthas, waste plastics, which are currently in large quantities, are being recycled in the form of oil, which is an integral part of the recycling process, with an initial boiling point of 38 to 60 ° C and an end point of 180 to 2 Regenerated oil fractionated to 20 ° C can also be used. Since these re-refined oils are desulfurized at the stage of naphtha, which is the raw material for plastics, SO x in the gas can be further reduced.

When using these recycled oils, if the initial boiling point is lower than 38 ° C, startability will be significantly reduced in low temperatures and in cold regions, and the same startability as gasoline will not be obtained. If the end point is higher than 220 ° C, the engine will not be able to generate the engine power as designed at high engine speeds. C, It is preferable to use a re-refined oil fractionated to an end point of 180 to 220 ° C.

As for the ratio of these hydrocarbon components in the synthetic fuel, when the hydrocarbon ratio is 20% by weight or less, the alcohol component and the ether component are increased, and the combustion speed is lower than that of the conventional gasoline, as in the case where the alcohol amount is large. As a result, the combustion speed becomes far apart from that of the internal combustion engine, and the speed of the internal combustion engine, such as a car, whose rotation speed changes frequently, is poor in following the acceleration. On the other hand, if the hydrocarbon ratio exceeds 80% by weight, the effect of reducing CO, HC and NOx in the exhaust gas is reduced. 'Next, as the ether component, at least one kind of ether having 12 or less carbon atoms in the molecule and having at least one ether bond in the molecule can be used.

As for the ratio of these ether components in the synthetic fuel, if the ether ratio is 5% by weight or less, the hydrocarbon component and the alcohol component become associated with the elapse of storage time and the absorption of moisture in the air. If the ether ratio is more than 20% by weight, ether odor will be generated as fuel, and volatility will be improved, the amount of evaporation will increase, and the loss in stockpiling as fuel will increase. The content may be 5 to 20% by weight.

As the ether to be compounded, any ether having at least an ether bond in the molecule can be used, and the number of carbon atoms in the ether molecule used (the number of hydrogen atoms bonded to the carbon) Changes the amount of NO x in the exhaust gas. Figure 4 shows the number of carbon atoms in the ether molecule and the change in NOx in the exhaust gas. In this test, acetyl ether was used as the ether having 4 carbon atoms as the ether of Formulation Example 7 described later, and methyl tertiary butyl ether (M. T. B. E) is converted to an ether having 6 carbon atoms. Diethylene glycol dimethyl ether, ethylene glycol dimethyl ether as an ether having 8 carbon atoms, tertiary annealed methyl ether (TAME) as an ether having 9 carbon atoms, and ethylene glycol as an ether having 12 carbon atoms. Using dibutyl ether, the NOx amount of each fuel obtained was measured.

From these results, it can be seen that the NOx amount decreases as the number of carbon atoms in the ether increases, and it can be said that the use of an ether having a relatively large number of carbon atoms is effective in reducing the amount of NOx. When the number of carbon atoms is larger than 12 of the ethylene glycol dibutyl ether, not only the volatility of the ether is reduced, but also the price is high, and it is difficult to obtain a quantity as a fuel. It should be less than 1 2.

In addition, these ethers having a relatively large number of carbon atoms have a smaller polarity than ethers having a relatively small number of carbon atoms, and their ability to prevent the separation of a hydrocarbon from alcohol, which is originally intended for adding the ether, is reduced. The separation of hydrocarbons and alcohols tends to occur easily due to the absorption of water during long-term storage and the like. Like dimethyl ether and ethylene glycol getyl ether

By using two or more ether bonds in the molecule or using a compound having a hydroxyl group (OH) in addition to the ether bond in the molecule, such as ethylene glycol monoethyl ether, It is preferable to avoid the separation of hydrocarbons and alcohols due to a decrease in polarity. By using a compound having a plurality of ether bonds or a hydroxyl group (OH) in addition to these ether bonds in these molecules, the conventional low-molecular-weight method can be used. It is possible to obtain a separation prevention effect equal to or higher than that of ether having carbon number. Further, as these ethers, not only a single ether but also an ether having a high ability to prevent separation between a hydrocarbon and an alcohol and a low carbon number for the purpose of separating the hydrocarbon and the alcohol and reducing NOx, The ether having a relatively large number of carbon atoms may be used as a mixture.

In addition, as these ether components, methyl butyl ether (M.T.B.E.) which has recently become a problem in the United States, etc., even if it is inexpensive, is used. It is preferable not to include these MTBEs in the fuel.

As these ethers, besides the above-mentioned ethylene glycol dimethyl ether (molecular weight 90), diethylene glycol dimethyl ether (molecular weight 134), tertiary annealed methyl ether (TAME) and the like can also be suitably used. .

(Example)

FIG. 1 is a flowchart showing a method for producing a liquid fuel for an internal combustion engine of the present embodiment. The liquid fuel for an internal combustion engine of the present invention comprises at least two kinds of aliphatic primary alcohols, a saturated or unsaturated hydrocarbon having 9 or less carbon atoms, and a compound having 9 or less carbon atoms in the molecule. And a single component or a mixed ether containing an ether having at least two ether bonds, and each of these raw fuels is weighed to a predetermined weight percent, and has a relatively large weight ratio, First, ether having a polarity smaller than that of the aliphatic primary alcohol is added to and mixed with the lightest naphtha as the hydrocarbon having the smallest value.

At this time, when two or more aliphatic primary alcohols are used as the alcohol, the alcohol is gradually added in the order of small alcohol having a small number of carbon atoms, and then the alcohol having a small number of carbon atoms is added. Is preferred.

After the addition of the alcohol, the specific gravity of the mixed liquid fuel is measured, and if the specific gravity is 0.735 or more and a predetermined specific gravity (in this embodiment, 0.755) or less, The alcohol is appropriately added to adjust the specific gravity so that the specific gravity becomes 0.755.

Figure 3 shows the relationship between the specific gravity of these fuels and fuel efficiency. From this result, when the specific gravity is less than 0.735, the fuel efficiency is significantly worse than the fuel efficiency of conventional gasoline (7.83 Km / liter), whereas it is 0.775 or more. As a result, the slope of the change curve of the fuel efficiency decreases, and it becomes almost similar to the fuel efficiency of the conventional gasoline.Therefore, by setting the specific gravity of these obtained fuels to 0.735 or more, It turns out that it is possible to obtain fuel efficiency that is almost equal to gasoline or more. As described above, it is preferable that raw fuels can be prevented from being separated by mixing those having similar polarities sequentially, and efficient mixing can be performed. However, the present invention is not limited to this. Further, in the above, the ether and the alcohol are sequentially charged and mixed into the low-polarity light-weight naphtha, but conversely, the ether and the light-weight naphtha may be sequentially charged into the high-polarity alcohol.

Hereinafter, examples of blending of the fuel for an internal combustion engine manufactured by the above-described manufacturing method are shown below.

《Formulation Example 1》

25% by weight of isobutyl alcohol (IBA), 10% by weight of ethanol, 13% by weight of isopropyl alcohol (IPA) as the aliphatic monohydric alcohol, and 13% by weight of diethylene glycol dimethyl as the ether component 7% by weight of ether, and 45% by weight of straight-chain hydrocarbons such as light naphtha, gasoline, or oil-regenerated hydrocarbon oil of waste plastics.

《Formulation Example 2》

25% by weight of n-butyl alcohol, 13% by weight of isopropyl alcohol (IPA), 10% by weight of ethanol, diethylene glycol as ether component Dimethyl ether is 7% by weight, and the linear hydrocarbon is 45% by weight of light naphtha, gasoline, or waste plastics.

<< Formulation Example 3 >>

35% by weight of ethanol, 13% by weight of isopropyl alcohol (IPA) as the aliphatic monohydric alcohol, 7% by weight of diethylene glycol dimethyl ether as the ether component, and the linear hydrocarbon Of 45% by weight of light naphtha, gasoline, or regenerated hydrocarbon oil from waste plastics.

《Formulation Example 4》

25% by weight of n-propanol, 13% by weight of n-butanol, 10% by weight of ethanol, and 7% of diethylene glycol dimethyl ether as the ether component. % By weight, as the straight-chain hydrocarbon Of 45% by weight of light naphtha, gasoline, or regenerated hydrocarbon oil from waste plastics.

《Formulation Example 5》

As aliphatic monohydric alcohols, 25% by weight of n-butanol, 10% by weight of ethanol, and 13% by weight of another one are 2-ethyl-1-propanol. Diethylene glycol dimethyl ether was 7% by weight as the tellurium component, and 45% by weight of any of light naphtha, gasoline, and regenerated hydrocarbon oil from waste plastic was used as the linear hydrocarbon.

<< Formulation Example 6 >>

As aliphatic monohydric alcohols, one is n-octal 25% by weight, ethanol is 10% by weight, the other is n-pentanol 13% by weight, and ethanol is an alcohol component. Diethylene glycol dimethyl ether is 7% by weight, and the linear hydrocarbon is 45% by volume of any of light naphtha, gasoline, and regenerated hydrocarbon oil of waste plastic.

<< Formulation Example 7 >>

25% by weight of normal alcohol (NBA), 7% by weight of isopropyl alcohol (IPA), 16% by weight of ethanol, and 7% by weight of diethylene glycol dimethyl ether as an ether component as aliphatic monohydric alcohol % Of any of light naphtha, gasoline, and waste plastic oil reclaimed hydrocarbon oil as the linear hydrocarbon.

《Formulation Example 8》

As aliphatic monohydric alcohols, one was 20% by weight of isobutyl alcohol (IBA), the other was 10% by weight of isopropyl alcohol (IPA), and 5% by weight of diethylene glycol dimethyl ether was used as an ether component. Either light naphtha, gasoline, or petroleum regenerated hydrocarbon oil from waste plastics is used as the chain hydrocarbon at 65% by weight.

《Formulation Example 9》

20% by weight of n-butyl alcohol and 10% by weight of isopropyl alcohol (IPA) as ether component 5% by weight of diethylene glycol dimethyl ether, and 65% by weight of any of light naphtha, gasoline, and regenerated hydrocarbon oil of waste plastic as the linear hydrocarbon.

<< Formulation Example 10 >>

As aliphatic monohydric alcohols, one is 20% by weight of ethanol, the other is 10% by weight of isopropyl alcohol (IPA), 5% by weight of ethylene glycol dimethyl ether is an ether component, A hydrocarbon containing 65% by weight of light naphtha, gasoline, or regenerated hydrocarbon oil from waste plastics.

《Formulation Example 1 1》

20% by weight of n-propanol as one of the aliphatic monohydric alcohols, 10% by weight of n-butanol as the other one, 5% by weight of diethylene glycol dimethyl ether as an ether component, the linear hydrocarbon Either light naphtha, gasoline, or waste plastic oil reclaimed hydrocarbon oil is 65% by weight.

《Formulation example 1 2》

As aliphatic monohydric alcohols, one is 20% by weight of n-butanol, the other is 10% by weight of 2-ethyl-1-propanol, and 5% by weight of diethylene glycol dimethyl ether is an ether component. A straight-chain hydrocarbon containing 65% by weight of light naphtha, gasoline, or regenerated hydrocarbon oil from waste plastic.

《Formulation Example 1 3》

As aliphatic monohydric alcohols, one is 20% by weight of n-octal, the other is 10% by weight of n-pentanol, 5% by weight of diethylene glycol dimethyl ether as an ether component, and the linear chain. Either light naphtha, gazolin, or oil-regenerated hydrocarbon oil from waste plastics is used as 65% by volume. Comparative Example 1>

43% by volume of methyl alcohol, 5% by volume of isopropyl alcohol (IPA) and 4% by volume of methyl tertiary butyl ether (MTB E) as ether component The linear hydrocarbon Light naphtha gasoline is 48% by volume.

Comparative Example 2>

25% by weight of normal alcohol (NBA), 7% by weight of isopropyl alcohol (IPA), 16% by weight of ethanol as another aliphatic monohydric alcohol, and MTBE 7 as a hybrid ether % By weight, wherein the linear hydrocarbon is 45% by weight of light naphtha, gasoline, or waste plastic oil regenerated hydrocarbon oil.

Comparative Example 3>

25% by weight of normal butanol (NBA), 7% by weight of isopropyl alcohol (IPA), 16% by weight of ethanol and 7% by weight of getyl ether as aliphatic monohydric alcohols Either light naphtha, gasoline, or oil-recycled hydrocarbon oil from waste plastics is used as a linear hydrocarbon at 45% by weight. As a test to confirm the long-term storage stability of each of the following formulations using each of these formulations, the results of experiments comparing the amounts of water that would cause separation to occur by sequentially adding water to each formulation are shown below. Show.

X: Separation 〇: No separation

From this test result, it can be seen that in the case of Compound 7, which contains three ether bonds inside the ether molecule and contains diethylene glycol dimethyl ether having the number of carbon atoms in the ether molecule of 7, the water absorbs water after long-term storage. However, it can be seen that separation is less likely to occur at or above the level of conventional synthetic fuels.

Although the embodiments of the present invention have been described in the above embodiments, the present invention is not limited to these embodiments, and changes and additions without departing from the gist of the present invention, namely, It is optional to add other raw fuels and additives (including metals, etc.) as long as the characteristics of the fuel for an internal combustion engine of the invention do not significantly change. Needless to say, fuel for an internal combustion engine is also included in the present invention.

Claims

The scope of the claims

1. A low-pollution synthetic liquid fuel for an internal combustion engine containing at least a saturated or unsaturated hydrocarbon having 12 or less carbon atoms, an alcohol and ether, wherein the ether has at least two ether bonds in its molecule. A low-pollution synthetic liquid fuel for an internal combustion engine, comprising an ether having the formula:

2. The low-pollution synthetic liquid fuel for an internal combustion engine according to claim 1, wherein the number of carbon atoms in the ether molecule having at least two ether bonds is 4 or more.

3. The low-pollution synthetic liquid fuel for an internal combustion engine according to claim 2, wherein the ether having at least two ether bonds is ethylene glycol dimethyl ether.

4. The low-pollution synthetic liquid fuel for an internal combustion engine according to any one of claims 1 to 3, wherein the ether does not contain methyl isobutyl butyl ether (M.T.B.E.).

5. As the alcohol, 15 to 75% by weight of an aliphatic monohydric alcohol, 20 to 80% by weight of a saturated or unsaturated hydrocarbon having 9 or less carbon atoms, and The low-pollution synthetic liquid fuel for an internal combustion engine according to any one of claims 1 to 5, comprising 5 to 20% by weight of an ether containing an ether having at least two ether bonds.