JP4640550B2 - Method for producing fuel composition for lean burn engine - Google Patents

Description

The present invention relates to a method for producing a gasoline composition, and more particularly, to a method for producing a fuel composition for a gasoline engine that is less likely to misfire even when used in a lean burn engine and has little reduction in engine output.

  Automobiles are required to have less harmful substances contained in exhaust gas and to have good fuel efficiency. Examples of methods for improving fuel efficiency include (1) a method for improving the thermal efficiency by increasing the compression ratio of the engine, and (2) a method for reducing pump loss which is a mechanical loss by lean burn combustion with an increased excess air ratio. . However, engines with a high compression ratio such as (1) have the merit that high output can be obtained, so in general, many are designed for high output, and few are aimed at improving fuel efficiency. . In addition, if the compression ratio is increased, knocking is likely to occur, so gasoline with a high octane number is required. However, even if the gasoline has a high octane number, the octane number is about 100, and there is a limit to improving the compression ratio.

  For these reasons, the method (2) using the lean burn engine is often adopted as a means for reducing fuel consumption. However, when the engine is operating in the lean burn region, the excess air ratio becomes high and combustion tends to become unstable. For this reason, output reduction, drivability deterioration, and exhaust gas performance are likely to deteriorate. For this reason, the normal excess air ratio is limited to about 1.2.

  In order to obtain a fuel that is difficult to misfire, it is known that a light fuel composed mainly of aliphatic hydrocarbons may be used. However, since the amount of heat generated per volume of such a fuel decreases, there is a problem that the engine output decreases in an excess fuel region to a stoichiometric mixture ratio where engine output is required during acceleration or the like.

  In addition, demands for improving the fuel efficiency of gasoline engines are increasing, and not only lean burn engines but also ordinary engines are required to operate with a high excess air ratio. For this reason, there has been a demand for gasoline fuel that is unlikely to misfire even when the excess air ratio is increased, and that causes little reduction in engine output.

The present invention has been made to solve such a problem, and an object of the present invention is to reduce the risk of misfiring when the excess air ratio is increased in a lean burn engine and to reduce gasoline engine output . It is to provide a manufacturing method .

  In order to prevent a decrease in engine output, a fuel containing a catalytic reforming gasoline base material is essential. The present inventors examined the octane number of gasoline, the distillation properties, etc. in order to obtain a fuel having a high flame speed for such fuel. However, satisfactory results were not obtained even when parameters such as octane number and distillation properties were changed.

As the study progressed, it was found that the flame speed of a fuel prepared by mixing an alkylate gasoline base, a catalytic reformed gasoline base and a light catalytic cracked gasoline base with a specific composition was fast (low misfire). As a result of further investigation, 5 to 50 parts by volume of alkylate gasoline, 5 to 50 parts by volume of catalytic reformed gasoline, 5 to 50 of one or more kinds of gasoline selected from the group consisting of light catalytic cracked gasoline and coker light gasoline are used. a fuel obtained by blending parts by volume carbon number of 9 or more components of the catalytic reforming of gasoline fuel is, found that flame speed of the fuel is less than 15 volume% of the total fuel is earlier, to complete the present invention It was.

  The fuel of the present invention has a high flame speed in the lean burn combustion region and is difficult to misfire. Therefore, by using such fuel in a lean burn engine, the engine output is stabilized at a low load, and the air-fuel ratio is not lowered more than necessary. For this reason, it is expected that fuel efficiency can be significantly improved.

  As a base material of gasoline of the present invention, a heavy oil is used as a raw material, and a light fraction of catalytic cracking gasoline obtained by reacting in a fluid state with a finely divided catalyst in which an active metal is supported on silica-alumina oxide or the like. Mineral catalytic cracking gasoline or coke production equipment is used as a raw material for coker light gasoline or heavy naphtha obtained when pyrolyzing heavy oil such as reduced pressure residue, and mixed with hydrogen to use platinum-based granular catalyst The catalytically modified gasoline obtained in this manner or the alkylate gasoline obtained by alkylating a lower hydrocarbon such as isobutane with a lower olefin such as propylene is used. As these base materials, those which are usually available can be used. However, in order to produce the gasoline fuel of the present invention, the distillation properties of the coker light gasoline base and the catalytic cracked gasoline base are limited.

Although it is a catalytic cracking gasoline base, a light fraction having a 95% distillation temperature of about 70 to 110 ° C. is excellent in flame speed. Therefore, in the present invention, a light fraction is essential. The 95% distillation temperature of the catalytic cracking gasoline base is 70 to 110 ° C, preferably 70 to 85 ° C. In the present invention, catalytic cracking gasoline having a 95% distillation temperature of 70 to 110 ° C. is referred to as light catalytic cracking gasoline. If the 95% distillation temperature exceeds 110 ° C., the flame speed of the finally obtained gasoline composition decreases, which is not preferable. Further, when the temperature falls below 70 ° C., the lightening is progressed too much, and the finally obtained gasoline composition may deviate from the fuel standard (JIS K2202 etc.) .

On the other hand, the coker light gasoline base material used in the fuel composition of the present invention uses a 95% distillation temperature of 70 to 110 ° C., preferably 70 to 85 ° C., in order to meet the fuel specifications as described above. .

  The catalytic reforming gasoline base is not particularly limited, and a normal one can be used. The general properties of ordinary products are that the initial boiling point is 70 to 100 ° C and the 95% distillation temperature is 130 to 175 ° C.

Moreover, the fraction which mainly contains a C6-C8 component can also be used as a catalytic reforming gasoline base material. However, when a large amount of components having 9 or more carbon atoms is mixed, the flame speed tends to decrease. For this reason, the component having 9 or more carbon atoms is set to 15% by volume or less of the entire fuel .

  There is no restriction | limiting in particular about an alkylate gasoline base material, A thing with an initial boiling point of 25-45 degreeC and a 95% distillation temperature of 130-190 degreeC can be used as a general property.

The main components of the gasoline fuel of the present invention are an alkylate gasoline base, a light catalytic cracking gasoline base, a coker light gasoline base and a catalytic reformed gasoline base. If necessary, a vapor pressure adjusting component, a detergent and the like are blended to obtain a final product. In the fuel composition of the present invention, 10 parts by volume of alkylate gasoline, 5-50 parts by volume of catalytic reformed gasoline, 5-50 of one or more kinds of gasoline selected from the group consisting of light catalytic cracked gasoline and coker light gasoline. The capacity part is blended, and the component having 9 or more carbon atoms in the catalytic reformed gasoline is made 15% by volume or less of the whole fuel.

In the present invention , the alkylate gasoline is selected from the group consisting of 10 parts by volume, the catalytically modified gasoline base is 5 to 50 parts by volume, preferably 7 to 40 parts by volume, the light catalytic cracking gasoline base and the coker light gasoline base. 5 to 50 parts by volume, preferably 7 to 40 parts by volume of the one or more base materials to be mixed are blended. In this case, the ratio of the volume part of one or more base materials selected from the group consisting of a light catalytic cracking gasoline base material and a coker light gasoline base material to the capacity part of the catalytic reforming gasoline base material is 20 to 100%, The range of 25 to 100% is preferable. Within this range, a fuel composition having a high flame speed can be obtained. Accordingly, the ratio of any one of the alkylate gasoline base, the catalytic reformed gasoline base, and one or more base materials selected from the group consisting of the light catalytic cracking gasoline base and the coker light gasoline base is extremely small. As a result, the flame speed decreases.

  In addition to the above components, a fraction having 4 to 5 carbon atoms can be added in an amount of 0 to 8% by volume in order to secure a certain vapor pressure and keep the engine startability good.

Since the fuel of the present invention described above contains a catalytically reformed gasoline base material, there is little decrease in engine output even in a region where the fuel excess region is stoichiometrically mixed as in acceleration. In particular, the fuel containing a large amount of the catalytically reformed gasoline base material of the present invention is considered to be suitable as a fuel for automobiles equipped with a high-power engine because the decrease in engine output is small.

The test fuel reference fuel was an alkylate gasoline base. The test fuel used was a mixture of the following gasoline bases (a), (b) and (c) in the proportions shown in Tables 5 and 7.
(A) Alkylate gasoline base material (b) Catalytic reforming gasoline base material A or catalytic reforming gasoline base material fraction B having 9 or more carbon atoms
(C) Heavy catalytic cracking gasoline (2 types of A or B), Light catalytic cracking gasoline base (2 types of A or B) or Coker light gasoline base High-octane gasoline that is our product for comparison It was also measured for a composition of fuel (GP1 plus) and alkylate gasoline base: contact reformed gasoline base A = 1: 1. Table 1 and Table 2 show the main properties of each of the above gasoline base materials (measurement in accordance with JIS K2536).

Test apparatus and flame speed measurement method Tests were carried out using an engine of various specifications shown in Table 3. The excess air ratio was 1.1, 1.2 and 1.3, and the flame speed was measured. The flame speed was calculated by installing an ion probe on the cylinder head and measuring the delay time from ignition.

Comparative parameter of flame speed In the present invention, as a parameter for comparing the flame speed, P. of flame speed at air excess ratios 1.1, 1.2 and 1.3 is used. I. (Power Index) is measured. I. The total value of was used. P. I. The value is expressed by the following formula.

  The improvement rate of the flame speed of a certain fuel is a value obtained by dividing the flame speed of a certain fuel by the flame speed of the fuel of the alkylate gasoline alone as the reference fuel. Further, the fuel improvement ratio indicating the maximum improvement ratio is a value obtained by dividing the flame speed of the fuel indicating the maximum improvement ratio by the flame speed of the fuel of the alkylate gasoline alone as the reference fuel. In other words, the fuel P.A. I. The value is 1. Since the tests were conducted with excess air ratios 1.1, 1.2, and 1.3, the sum is 3 if a particular fuel exhibits the maximum burning rate at all excess air ratios. In the present invention, the fuel that exhibits the highest improvement rate in the excess air ratio 1.1 is that of 10 parts by volume of alkylate gasoline base, 10 parts by volume of catalytic reformed gasoline base, and 30 parts by volume of light catalytic cracking gasoline base. Met. In the excess air ratios of 1.2 and 1.3, 10 parts by volume of the alkylate gasoline base, 10 parts by volume of the catalytic reformed gasoline base A, and 30 parts by volume of the coker light gasoline base showed the highest improvement rate.

Example 1
A fuel composition was prepared by mixing 10 parts by volume of alkylate gasoline base, 10 parts by volume of catalytic reformed gasoline base A, and 30 parts by volume of light catalytic cracking gasoline base A. Table 4 shows the distillation properties of this fuel. In addition, the mixed composition of this fuel and P.I. I. Table 5 summarizes the total values. This fuel is P.I. I. The total value was 2.803, which was a very high value.

(Examples 2 to 3 )
Example except that the light catalytic cracking gasoline base material A of Example 1 is mixed with a coker light gasoline base material (Example 2) or the light catalytic cracking gasoline base material B is blended (Example 3). In the same manner as in Example 1, two fuel compositions were prepared. Table 4 shows the distillation properties of these fuels. These fuel compositions and P.P. I. Table 5 summarizes the total values. P. of these fuels. I. The total values were 2.789 and 1.898, respectively.

(Example 5)
A fuel was prepared by mixing 10 parts by volume of an alkylate gasoline base, 7.5 parts by volume of a catalytic reformed gasoline base A, and 7.5 parts by volume of a light catalytic cracking gasoline base A. Table 4 shows the distillation properties of this fuel. Also, the fuel composition and P.I. I. Table 5 summarizes the total values. P. of this fuel. I. The total value was 2.483.

(Example 6)
A fuel was prepared by mixing 10 parts by volume of an alkylate gasoline base, 30 parts by volume of a catalytic reformed gasoline base A, and 10 parts by volume of a light catalytic cracking gasoline base A. Table 4 shows the distillation properties of this fuel. Also, the fuel composition and P.I. I. Table 5 summarizes these values. P. of this fuel. I. The total value was 1.982.

(Example 7)
A fuel was prepared in the same manner as in Example 6 except that the light catalytic cracking gasoline base A of Example 6 was replaced with a coker light gasoline base. Table 4 shows the distillation properties of this fuel. Also, the fuel composition and P.I. I. Table 5 summarizes these values. P. of this fuel. I. The total value was 1.434.

(Examples 8 to 12)
Fuels having the compositions shown in Table 5 were prepared in the same manner as in Examples 1-7. In addition, these fuels are listed in Table 5 below. I. Had a total value of.

(Comparative Example 1)
A fuel was prepared by mixing 10 parts by volume of an alkylate gasoline base, 3 parts by volume of catalytic reformed gasoline base A, and 3 parts by volume of catalytic cracked gasoline base B. Table 6 shows the distillation properties of this fuel. Also, the fuel composition and P.I. I. Table 7 summarizes these values. P. of this fuel. I. The total value was 0.585.

(Comparative Example 2)
A fuel was prepared by mixing 10 parts by volume of an alkylate gasoline base, 30 parts by volume of a catalytic reformed gasoline base A, and 10 parts by volume of a catalytic cracked gasoline base A. Table 6 shows the distillation properties of this fuel. Also, the fuel composition and P.I. I. Table 7 summarizes these values. P. of this fuel. I. The total value was 0.992.

(Comparative Example 3)
A fuel composition was prepared by mixing 10 parts by volume of an alkylate gasoline base and 10 parts by volume of a catalytically modified gasoline base A. Table 6 shows the distillation properties of this fuel. Also, the fuel composition and P.I. I. Table 7 summarizes these values. P. of this fuel. I. The total value was 0.740.

(Comparative Example 4)
10 parts by volume of alkylate gasoline base and 10 parts by volume of the carbon reformed gasoline base fraction (contact reformed gasoline base B) of 10 parts by volume and 30 parts by weight of light catalytic cracking gasoline base A was mixed to prepare a fuel. Table 6 shows the distillation properties of this fuel. Also, the fuel composition and P.I. I. Table 7 summarizes these values. P. of this fuel. I. The total value was 1.228.

(Comparative Example 5)
A fuel was prepared by mixing 10 parts by volume of an alkylate gasoline base, 3 parts by volume of a catalytic reformed gasoline base A, and 3 parts by volume of a cocalite gasoline base. Table 6 shows the distillation properties of this fuel. Also, the fuel composition and P.I. I. Table 7 summarizes these values. P. of this fuel. I. The total value was 0.996.

(Comparative Examples 6-19)
Fuels having the compositions shown in Table 7 were prepared in the same manner as Comparative Examples 1-5. In addition, these fuels are listed in Table 7 below. I. Had a total value of.

(Reference Example 1)
Our high octane gasoline product (GP1 plus) was tested. P. of this fuel. I. The total value was 1.270.

  As is clear from the above Examples and Comparative Examples, by using the present invention, it is possible to obtain a fuel composition that has a high flame speed and is difficult to misfire in a lean burn combustion region where the excess air ratio is high. Even outside the scope of the present invention, for example, a fuel having a relatively high flame speed as in Comparative Example 19 shown in Table 7 may be obtained. However, outside of the scope of the present invention, P.P. I. The value often changes greatly, and it is difficult to stably supply fuel with a high flame speed.

Claims (1)

A lean burn engine containing 10 parts by volume of alkylate gasoline, 5 to 50 parts by volume of catalytic reformed gasoline, 5 to 50 parts by volume of one or more kinds of gasoline selected from the group consisting of light catalytic cracking gasoline and coker light gasoline A method for producing a fuel composition for a vehicle, comprising:
A method for producing a fuel composition for a lean burn engine, wherein the component having 9 or more carbon atoms in the catalytic reformed gasoline is blended so as to be 15% by volume or less of the whole fuel composition.