MIXED FUEL SUITABLE FOR DIESEL ENGINES

Abstract

The present invention a mixed fuel suitable for diesel engines, which consists of the following components by volume percentage: 35% to 37.5% of diesel, 35% to 37.5% of ethanol and 25% to 30% of PODE, wherein the diesel is petroleum diesel having a cetane number not less than 48; the purity of the ethanol by mass percentage is not less than 99.5%; and, the PODE is a mixture of two fuels shown by molecular formulae CH.sub.3O(CH.sub.2O).sub.3CH.sub.3 and CH.sub.3O(CH.sub.2O).sub.4CH.sub.3. The use of this fuel is advantageous for emission reduction.

Claims

1. A mixed fuel suitable for diesel engines, consisting of the following components by volume percentage: 35% to 37.5% of diesel, 35% to 37.5% of ethanol and 25% to 30% of PODE; the diesel is petroleum diesel having a cetane number not less than 48; the purity of the ethanol by mass percentage is not less than 99.5%; and the PODE is a mixture of two fuels shown by molecular formulae CH.sub.3O(CH.sub.2O).sub.3CH.sub.3 and CH.sub.3O(CH.sub.2O).sub.4CH.sub.3.

2. The mixed fuel suitable for diesel engines according to claim 1, wherein the volume percentage of the fuel shown by the molecular formula CH.sub.3O(CH.sub.2O).sub.3CH.sub.3 in the PODE is 50% to 80%.

3. The mixed fuel suitable for diesel engines according to claim 1 or 2, wherein the mixed fuel consists of the following components by volume percentage: 36% of diesel, 36% of ethanol and 28% of PODE.

4. The mixed fuel suitable for diesel engines according to claim 3, wherein the content of sulfur in the diesel is less than 10 ppm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1 shows the miscibility of diesel and ethanol at different temperatures;

[0018] FIG. 2 shows the miscibility of diesel/ethanol/PODE in different proportions under the temperature of 20° C.; and

[0019] FIG. 3 shows the miscibility of diesel/ethanol/PODE in different proportions under the temperature of 30° C.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0020] The following implementations are used for describing the present invention, rather than limiting the scope of the present invention.

[0021] The present invention provides a mixed fuel suitable for diesel engines, which consists of the following components by volume percentage:

[0022] 35% to 37.5% of diesel, 35% to 37.5% of ethanol and 25% to 30% of PODE.

[0023] The diesel is petroleum diesel having a cetane number not less than 48 and is commercially available. The purity of the ethanol by mass percentage is not less than 99.5%.

[0024] The PODE is a mixture of two fuels shown by molecular formulae CH.sub.3O(CH.sub.2O).sub.3CH.sub.3 and CH.sub.3O(CH.sub.2O).sub.4CH.sub.3.

[0025] Preferably, the volume percentage of the fuel shown by the molecular formula CH.sub.3O(CH.sub.2O).sub.3CH.sub.3 in the PODE is 50% to 80%.

[0026] Preferably, the mixed fuel consists of the following components by volume percentage: 36% of diesel, 36% of ethanol and 28% of PODE.

[0027] Preferably, the content of sulfur in the diesel is less than 10 ppm. It can be seen from FIG. 1 that, when the ethanol proportion of the mixed fuel is 10% to 90%, the miscibility of diesel and ethanol cannot be realized at the normal temperature of 25° C. and can only be realized at a high temperature, but the ambient temperature often cannot reach the miscibility temperature. However, it can be seen from FIGS. 2 and 3 that there are a miscibility area above the curve and a layering area below the curve and the miscibility of diesel/ethanol can be realized at a low temperature by titrating the PODE. Under the temperature of 20° C., the miscibility of diesel/ethanol can be realized by at most 26% of PODE by volume percentage; and, under the temperature of 30° C., the miscibility of diesel/ethanol can be realized by at most 13% by volume percentage.

[0028] Apparently, the respective proportion of the diesel/ethanol/PODE needs to satisfy the miscibility principle.

[0029] A method for preparing the fuel of the present invention includes the following steps of: preparing the components in volume proportion, adding ethanol in the diesel to form a mixed solution of incomplete mutual solubility, adding PODE in the mixed solution while stirring, and mixing uniformly to obtain a mixed fuel.

[0030] The cetane number of the mixed fuel provided by the present invention is within the range from 45 to 55.

[0031] In the mixed fuel provided by the present invention, the diesel/ethanol/PODE has good miscibility, so the mixed fuel can be stored for a long term without layering.

Embodiment 1

[0032] The mixed fuel consists of 37.5 L of diesel, 37.5 L of ethanol and 25 L of PODE.

[0033] The diesel is petroleum diesel having a cetane number not less than 48. The purity of the ethanol by mass percentage is 99.5%.

[0034] The PODE is a mixture of two fuels shown by molecular formulae CH.sub.3O(CH.sub.2O).sub.3CH.sub.3 and CH.sub.3O(CH.sub.2O).sub.4CH.sub.3.

[0035] The volume percentage of the fuel shown by the molecular formula CH.sub.3O(CH.sub.2O).sub.3CH.sub.3 in the PODE is 50%.

[0036] The content of sulfur in the diesel is less than 10 ppm.

[0037] The method for preparing the fuel of the embodiment 1 of the present invention includes the following steps of: preparing the components in volume proportion, adding ethanol in the diesel to form a mixed solution of incomplete mutual solubility, adding PODE in the mixed solution while stirring, and mixing uniformly to obtain a mixed fuel. The preparation methods in the following embodiments are the same as that in Embodiment 1.

Embodiment 2

[0038] The mixed fuel consists of 37 L of diesel, 37 L of ethanol and 26 L of PODE.

[0039] The diesel is petroleum diesel having a cetane number not less than 48. The purity of the ethanol by mass percentage is 99.5%.

[0040] The PODE is a mixture of two fuels shown by molecular formulae CH.sub.3O(CH.sub.2O).sub.3CH.sub.3 and CH.sub.3O(CH.sub.2O).sub.4CH.sub.3.

[0041] The volume percentage of the fuel shown by the molecular formula CH.sub.3O(CH.sub.2O).sub.3CH.sub.3 in the PODE is 60%.

[0042] The content of sulfur in the diesel is less than 10 ppm.

Embodiment 3

[0043] The mixed fuel consists of 36.5 L of diesel, 36.5 L of ethanol and 27 L of PODE.

[0044] The diesel is petroleum diesel oil having a cetane number not less than 48. The purity of the ethanol by mass percentage is 99.5%.

[0045] The PODE is a mixture of two fuels shown by molecular formulae CH.sub.3O(CH.sub.2O).sub.3CH.sub.3 and CH.sub.3O(CH.sub.2O).sub.4CH.sub.3.

[0046] The volume percentage of the fuel shown by the molecular formula CH.sub.3O(CH.sub.2O).sub.3CH.sub.3 in the PODE is 70%.

[0047] The content of sulfur in the diesel is less than 10 ppm.

Embodiment 4

[0048] The mixed fuel consists of 36 L of diesel, 36 L of ethanol and 28 L of PODE.

[0049] The diesel is petroleum diesel having a cetane number not less than 48. The purity of the ethanol by mass percentage is 99.5%.

[0050] The PODE is a mixture of two fuels shown by molecular formulae CH.sub.3O(CH.sub.2O).sub.3CH.sub.3 and CH.sub.3O(CH.sub.2O).sub.4CH.sub.3.

[0051] The volume percentage of the fuel shown by the molecular formula CH.sub.3O(CH.sub.2O).sub.3CH.sub.3 in the PODE is 80%.

[0052] The content of sulfur in the diesel is less than 10 ppm.

Embodiment 5

[0053] The mixed fuel consists of 35 L of diesel, 35 L of ethanol and 30 L of PODE.

[0054] The diesel is petroleum diesel having a cetane number not less than 48. The purity of the ethanol by mass percentage is 99.5%. The PODE is a mixture of two fuels shown by molecular formulae CH.sub.3O(CH.sub.2O).sub.3CH.sub.3 and CH.sub.3O(CH.sub.2O).sub.4CH.sub.3.

[0055] The volume percentage of the fuel shown by the molecular formula CH.sub.3O(CH.sub.2O).sub.3CH.sub.3 in the PODE is 65%.

[0056] The content of sulfur in the diesel is less than 10 ppm.

[0057] When the four mixed fuels obtained in Embodiments 1 to 5 are tested by a heavy-duty diesel engine having a displacement of 8.42 L, the results indicate that the smoke emission of the novel mixed fuel provided by the present invention is obviously lower (above 50%) than that of the diesel or the mixed fuel of diesel/PODEn and the emission of CO and THC is reduced to different extents.

[0058] The foregoing embodiments are merely preferred implementations of the present application and not intended to limit the scope of the present application. Various transformations and improvements made to the technical solutions of the present invention by a person of ordinary skill in the art without departing from the design spirit of the present invention shall fall into the protection scope defined by the appended claims of the present application.