JP5748408B2 - Biodiesel fuel - Google Patents

Description

  Biodiesel fuel

  Biodiesel is an alternative diesel fuel derived from vegetable oil or animal fat. Transesterification of oils or fats with alcohols (usually methanol, but in some cases, longer chain alcohols) converts fatty acid methyl esters (FAMEs) known as biodiesel. Bring.

  Biodiesel can be used by itself, but it is also mixed with a conventional diesel fuel base (diesel fuel base) to form a biodiesel blend. However, adding a relatively high proportion of biodiesel to a diesel fuel base results in a blend with poor cold flow properties. In cold climates, such fuels can lead to blockage of diesel injection nozzles with particles, primarily wax crystals. This places a limit on the amount and type of fatty acid methyl esters (FAME) that can be added to the biodiesel blend. This is especially true for fatty acid methyl esters which are mostly saturated. Cold filter plugging point (clogging point, CFPP) additives are used to improve CFPP, but such additives do not work well in the presence of FAMEs and blends thereof.

  The object of the present invention is to address the above problems.

[Summary of the present invention]
According to the present invention,
Biodiesel typically containing fatty acid methyl or ethyl esters,
And an added alcohol component that is not a natural component of the biodiesel,
An alternative diesel fuel is provided.

  The biodiesel is composed of fatty acid methyl esters, in particular fatty acid methyl esters having poor low temperature fluidity above -5 ° C, such as soya methyl ester (soybean oil methyl ester) (-2 ° C) and / or palm. Oil methyl ester (10 ° C.) and / or Jatropha oil methyl ester.

  The alcohol component includes higher alcohols having 3 or more carbon atoms, typically alcohols having 3 to 15, preferably 3 to 9, and most preferably 3 to 6 carbon atoms. Is preferred.

  The alternative diesel fuel preferably contains 0.2% to 5% v / v alcohol component, most preferably 0.5% to 3% v / v alcohol component.

The above alternative diesel fuels are:
A diesel fuel derived from a Fischer-Tropsch (FT) reaction and including or may contain a crude-derived diesel fuel;
Biodiesel typically comprising fatty acid methyl or ethyl esters; and one alcohol or alcohols;
Can be a diesel fuel blend.

  Typically, this diesel fuel blend comprises 60% to 90%, preferably about 70% v / v diesel fuel, and 10% to 40%, preferably about 30% v / v biodiesel. Including.

  The diesel fuel blend may be a GTL derived diesel fuel, for example, FT diesel by conversion of olefins to distillate (COD).

  The present invention relates to a method for improving the plugging point of alternative diesel fuel, in which an alcohol component is added to biodiesel fuel (typically containing fatty acid methyl or ethyl esters).

  The biodiesel is composed of fatty methyl esters, in particular fatty methyl esters having poor cold flow properties higher than −5 ° C., such as soya methyl ester (soybean oil methyl ester) (−2 ° C.) and / or palm. Oil methyl ester (10 ° C.) and / or Jatropha oil methyl ester.

  The alcohol component is an alcohol (s) that is a higher alcohol (s) having 3 or more carbon atoms, typically 3-15, preferably 3-9, most preferably 3-9. It is preferable to include alcohols having 6 carbon atoms. The alcohol component can be at least 20% v / v, preferably at least 50% v / v branched alcohols.

  Preferably, the alcohol component comprises 0.2% to 5% v / v, most preferably 0.5% to 3% v / v of the alternative diesel fuel.

  The alternative diesel fuel is typically a diesel fuel blend, further comprising a diesel fuel derived from a Fischer-Tropsch (FT) reaction, and may or may contain a crude-derived diesel fuel. .

  Typically, 60% -80%, preferably about 70% v / v diesel fuel is blended with 20-40%, preferably about 30% v / v biodiesel.

  The diesel fuel is preferably derived from a Fischer-Tropsch (FT) reaction, most preferably from a GTL FT reaction.

FIG. 1 is a graph showing the effect of higher alcohols on the Clog Filter Plugging Point (CFPP) (° C.) in a diesel fuel blend. FIG. 2 is a graph showing the effect of higher alcohols on the flash point of a diesel fuel blend. FIG. 3 is a graph showing the effect of higher alcohols on the cetane number of diesel fuel blends. Figure 4 is a graph showing the effect of higher alcohols to NO _x vehicle emissions diesel fuel blends. FIG. 5 is a graph showing the effect of higher alcohols on the CO vehicle emissions of a diesel fuel blend. FIG. 6 is a graph showing the effect of higher alcohols on the CO ₂ vehicle emissions of diesel fuel blends. FIG. 7 is a graph showing the effect of higher alcohols on both HC + NO _x emissions of diesel fuel blends. FIG. 8 is a graph showing the effect of higher alcohols on PM vehicle emissions of a diesel fuel blend.

[Detailed Description of the Invention]
The present invention relates to the production of alternative fuels. Alternative fuels are substantially non-crude fuels such as biodiesel, Fischer-Tropsch derived fuel, COD diesel, and their diesel fuel blends.

  Fischer-Tropsch (FT) synthesis involves the conversion of carbon monoxide and hydrogen (synthesis gas) to higher hydrocarbon products.

  For low temperature Fischer-Tropsch (LTFT) synthesis, wax is the penultimate product. Waxes are converted by hydrocracking into short chains for use as high quality transportation fuels, primarily diesel fuel. For high temperature Fischer-Tropsch (HTFT) synthesis, distillates and naphtha are produced. These are reformed to diesel fuel and gasoline. During both FT steps, alcohols of various chain lengths are produced.

  The FT catalyst is typically supported on a variety of refractory supports such as alumina, silica, titania and the like. Group VIII refractory-supported metals are used to catalyze the FT reaction. These include cobalt, iron, ruthenium, etc., or mixtures of two or more thereof. Promoters may be added to the catalyst, including ruthenium, palladium, platinum, rhenium, lanthanum, and zirconium.

  Syngas can be obtained from coal by gasification and from natural gas by reforming or catalytic partial oxidation. Gas to Liquid (GTL) technology is the formation of a liquid product in an FT reaction from synthesis gas produced from natural gas. Overall, such a GTL process can be considered to be composed of three main elements, namely, the reforming of natural gas into syngas, the further synthesis gas into Fischer-Tropsch products Conversion, and hydrocarbon post-treatment to produce diesel, gasoline, olefins, and alcohols, mainly derived from FT, among others.

  A preferred diesel fuel is a synthetically derived diesel fuel derived from the COD method described in WO06069407, according to which light olefins (C3 to C10) are oligomerized on a zeolite-type catalyst. It becomes. The distillate fractionated from this COD product can be in the boiling range of 150-360 ° C, with a boiling range of 180-360 ° C being preferred. Such distillate is hydrotreated and fractionated to the preferred diesel boiling range. The hydrocarbon composition may be composed of the following components: n-paraffin (<10%), isoparaffin (50-80%), cyclic paraffin (5-30%), and monoaromatic (3-15% ). Monoaromatics (single ring) can be converted to cyclic paraffins by hydrogenation, resulting in almost zero aromatic content. Depending on the COD feed, some oxygenates may be present (<10%) (feeds containing oxygenates can affect this, but hydrogenation can convert them). This diesel fuel is sulfur free and has excellent low temperature fluidity (CFPP (clogging point) of less than -35 ° C and even less than -45 ° C, as tested by IP309).

We advantageously use palm oil methyl ester as a biodiesel blend component in a diesel blend because it is readily available and more per acre (4047 m ² ) than other vegetable oils. I found out the fact that it produces yield. However, for biodiesel fuel, when “heavy” fatty acid methyl esters (FAME) having CFPP higher than −5 ° C. are used as biodiesel components, problems related to low temperature fluidity (pour point, cloud point) , And clogging points (Cold Filter Plugging Point, CFPP). A problem inherent in palm oil methyl ester (PME) as a biofuel blend component is that it has poor low-temperature fluidity (CFPP (clogging point) at 10 ° C.), which is used as a fuel as it is. When used, it means that it cannot be used easily in weather below 10 ° C. and therefore has only a severely limited market potential. Although still better, soya (soy) methyl ester has a CFPP of -2 ° C, which is also problematic in colder climates (typically -15 ° C CFPP is required in European winters, On the other hand, -5 ° C CFPP is necessary in Europe summer).

  In accordance with the present invention, the inventors have been able to address the high CFPP problem by adding higher alcohols as a component to improve the low temperature fluidity of the blend. “Higher alcohol” means an alcohol having 3 or more carbon atoms.

  In accordance with the present invention, the improved diesel fuel blend comprises a diesel fuel, preferably a diesel fuel derived from a Fischer-Tropsch (FT) reaction, fatty acid methyl esters, and an alcohol component. This alcohol component is added and is not a natural component of biodiesel or diesel fuel.

  Diesel fuel (which may be a GTL derived diesel fuel) is typically included at about 70% v / v of the blend. The blend may include a portion of crude-derived diesel fuel.

  Fatty acid methyl esters (FAME) are typically included at about 30% v / v of the blend and can be derived from vegetable oils such as palm oil methyl ester (PME) and / or soybean oil. It may be methyl ester (SME).

  Table 1 below lists the types of vegetable oils used to prepare FAMEs suitable for use in the present invention.

  The alcohol component added to the blend typically includes a higher alcohol ("include" is greater than 80% v / v, preferably greater than 90% v / v of the alcohol component is composed of a higher alcohol. Added to the blend at a low percent volume, for example 0.2% to 5% v / v of the blend, typically 0.5% to 3% v / v Is done. The alcohol component can be at least 20%, preferably at least 50%, branched alcohols, the branches being predominantly (ie more than 50%) methyl branches.

  As is apparent from the examples, the addition of 0.5% of Mostanol 120 120 alcohol resulted in a significant improvement in the CFPP of the test blend from −2 ° C. to −11 ° C., this 9 ° C. The drop in is much better than that reported in the prior art. In addition, this is achieved without compromising other required fuel specifications. This higher alcohol improves the low temperature fluidity of the blend by a 9 ° C. reduction per 0.5-1% v / v (volume / volume) alcohol added.

  Another advantage of adding higher alcohols is that it reduces diesel foaming and also reduces diesel haze (water) because alcohol can eliminate water droplets suspended in the diesel. is there.

From FIGS. 4-7 it is also clear that the addition of higher alcohols indicates the following:
Most diesel emissions, such as carbon monoxide (CO), carbon dioxide (CO ₂ ), hydrocarbons (HC), and particulate matter (PM), are significantly reduced. Nitrogen oxide (NO _x ) emissions, which normally increase when biocomponents (FAME) are added to the fuel, have the opposite effect. The final combined NO _x + HC emissions meet the Euro 4 Vehicle Emission Specification of less than 0.3 g / kg for blends containing up to 27% v / v FAME (9% PME; 18% SME; 70% GTL, and 3% heavy alcohol).

The blends of the present invention comprising higher alcohols or higher alcohols have the following advantages over diesel and FAME blends that do not include the higher alcohols or higher alcohols:
-Improved CFPP (for use at lower temperatures)
-Improved cloud point (use at lower temperatures)
-Reduced particulate matter emissions from the exhaust pipe-Slightly increased cetane number (better combustion properties)
-Reduced diesel foaming (easier tank filling)
Reduced diesel haze in the presence of water (clarification of the presence of water that may be present from the FAME process)
Reduce the need for expensive low temperature flow performance additives

  Although the present invention described above relates to a diesel fuel blend, the present invention is widely deployed in the improvement of CFPP in biodiesel fuel by adding alternative diesel fuel and the above-described alcohol component in the above-mentioned amounts.

  The invention is explained in more detail on the basis of the following non-limiting examples.

  A series of biodiesel fuel blends were prepared using Fischer-Tropsch / Gas-to-Liquid derived diesel as the base fuel. For this test, an olefin conversion FT diesel (Conversion of Olefins (COD)) was used. FT-COD diesel has essentially good cold flow properties due to its high isoparaffinic properties. FT-COD diesel is generally similar to other FT diesels that have been upgraded to diesel by cracking and isomerizing FT derived waxes.

  The FAME used in the blend contained palm oil methyl ester (PME) and soybean oil methyl ester (SME).

  Low volume percent higher alcohols (3 to 6 carbon atoms) were added to the blend.

  The aim is to create an alternative biodiesel fuel that can be used in the existing transportation market without any further modification. In addition, this fuel maximizes the use of PME and provides excellent operating performance and excellent exhaust. Finally, this fuel can be blended with crude derived diesel.

  The blend was prepared in the volume ratio shown in Table 2 below.

  Table 3 below provides a typical composition of Moststanol P®.

  Table 4 below shows a typical composition of Mosstanol 120®.

[CFPP, flash point, and cetane number tests]
Table 5 below lists the composition and fuel properties of the blends used in the CFPP, flash point, and cetane number tests.

  The composition of the fuel blends A-F is shown in Table 2 above.

  Figures 1-3 graphically illustrate the cold filter plugging point (CFPP), flash point, and cetane number of base blend A compared to blends B and D-F of the present invention.

  Significant improvement was observed for CFPP with the addition of higher alcohols. The CFPP of base blend A (PME: SME: GTL diesel = 9: 20: 70) decreased from −2 ° C. to −12 ° C. with the addition of 0.5% v / v Mosstanol 120. The addition of 1% v / v Mosstanol P lowered the CFPP of the same base blend A from -2 ° C to -11 ° C, and the addition of 5% v / v lowered the CFPP to -15 ° C. . Please refer to FIG.

  The addition of higher alcohols does not lower the flash point to the point where the fuel cannot meet the 65 ° C standard. Addition of 1% v / v Mosstanol P® to the base blend results in a flash point of 89.5 ° C. FIG. 2 shows the effect of flash point on the addition of two higher alcohol blends.

  The cetane number increased with the addition of a small percentage of alcohol between 0.5 and 3% v / v. A high cetane number is desirable for diesel vehicle performance. Addition of 0.5% Mosstanol P® (C5 alcohol) increases the cetane number from 53.3 to 54.9 while adding 1% Mosstanol P® Resulted in an increase in cetane number from 53.3 to 57.4.

Blend D has been found to meet all modern diesel fuel standards and has the following additional advantages:
Improved CFPP reported over the base case
・ Reduced particulate matter (Particulate Matter), carbon monoxide, carbon dioxide, particulate matter from the exhaust port. Compliant with Euro4 vehicle emission standards.
• Nitrogen oxide emissions of blends containing higher alcohols were lower than similar blends without these alcohols.
-Increased cetane number-Reduced diesel foaming (easy tank filling)
Reduced need for expensive low temperature fluidity and other diesel performance additives.

[Vehicle test results]
The tests were conducted at the Volkswagen Exhaust Laboratory, South Africa, using the established exhaust emission test methods at the Euro 3 and 4 levels. The test vehicle was a Volkswagen Jetta A5 1.9 liter TDi (77kW) with an automatic transmission. The vehicle was built according to Euro4 level emissions. The staff of Stellenbosch Automotive Engineering (Pty) Ltd. independently tested.

  The test fuel was compared to CEC standard diesel, which was tested at the beginning and end of each batch.

  Table 6 below shows the composition and fuel properties of the blends used in this vehicle emissions test.

  The results of the exhaust test of the fuel H-N are shown in FIGS. In the figure, the emission reduction is graphed as a percentage increase / decrease relative to the standard CEC standard diesel used for the Euro4 type exhaust test.

For each figure, the actual emission values (g / km) for the specific emissions of the tested CEC standard diesel are shown along with the Euro4 limit value.
FIG. 4: NOx was 0.253 g / km against the CEC reference fuel. The limit value for Euro4 is 0.25 g / km.
FIG. 5: CO was 0.123 g / km relative to CEC reference fuel. The limit value for Euro4 is 0.5 g / km.
FIG. 6: CO ₂ was 167.3 g / km relative to the CEC reference fuel.
FIG. 7: HC + NOx was 0.275 g / km against the CEC reference fuel. The limit value for Euro4 is 0.3 g / km.
Figure 8: PM was 0.026g / km against CEC reference fuel. The limit value for Euro4 is 0.025 g / km.

As can be seen in FIGS. 4-8, a remarkable vehicle exhaust port exhaust were recorded CO, PM, and the CO _2. NO _x emissions for blends containing higher alcohols were lower than similar blends without these alcohols. Euro 4 exhaust emissions for CO, PM, CO ₂ , HC + NO _x were compatible with the given fuel blend.

Claims (17)

60% -85% v / v Fischer-Tropsch (FT) reaction / GTL derived diesel fuel;
Fatty acid methyl esters comprising soya methyl ester (soybean oil methyl ester) and / or palm oil methyl ester and / or jatropha (nanyo abragi) oil methyl ester, having a clogging point higher than −5 ° C. 10% ~30% v / v biodiesel fuel containing esters; and of 0.2% ~3% v / v, the alcohol component having 3 to 15 carbon atoms seen including,
An alternative diesel fuel blend having a flash point of 65 ° C or higher and a clogging point of -11 ° C or lower .   The alternative diesel fuel blend of claim 1, wherein the biodiesel fuel comprises palm oil methyl ester. 3. An alternative diesel fuel blend according to claim 1 or 2 , wherein the alcohol component comprises higher alcohol (s) having from 3 to 9 carbon atoms. The alternative diesel fuel blend of claim 3 , wherein the alcohol component comprises alcohol (s) having 3 to 6 carbon atoms. The alternative diesel fuel blend according to any one of claims 1 to 4 , wherein the alcohol component is an alcohol which is branched at least 20% v / v. 6. The alternative diesel fuel blend of claim 5 , wherein the alcohol component is an alcohol that is branched at least 50% v / v. The alternative diesel fuel blend according to any one of claims 1 to 6 , wherein the diesel fuel from the Fischer-Tropsch reaction is a COD diesel fuel. Including diesel fuel 70% v / v, alternative diesel fuel blend according to any one of claims 1-7. Containing biodiesel 30% v / v containing fatty acid methyl esters, alternative diesel fuel blend according to any one of claims 1-8. 60% -85% v / v Fischer-Tropsch (FT) reaction / GTL derived diesel fuel; and
Fatty acid methyl esters comprising soya methyl ester (soybean oil methyl ester) and / or palm oil methyl ester and / or jatropha (nanyo abragi) oil methyl ester, having a clogging point higher than −5 ° C. look containing biodiesel of 10% ~30% v / v containing esters have a flash point above 65 ° C., and, -11 ° C. with the following plugging point, eye alternative diesel fuel blends A method for improving the clogging point,
A method wherein an alcohol component having 3 to 15 carbon atoms is added to the alternative diesel fuel blend in an amount of 0.2% to 3% v / v. The method of claim 10 , wherein the biodiesel fuel comprises palm oil methyl ester. 12. The method according to claim 10 or 11 , wherein the alcohol component comprises alcohol (s) having 3 to 9 carbon atoms. The method of claim 12 , wherein the alcohol component comprises alcohol (s) having 3 to 6 carbon atoms. The method according to any one of claims 10 to 13 , wherein the alcohol component is an alcohol having at least 20% v / v branched. 15. The method of claim 14 , wherein the alcohol component is an alcohol that is branched at least 50% v / v. The method according to any one of claims 10 to 15 , wherein the diesel fuel is a COD diesel fuel. 17. A method according to any one of claims 10 to 16 , wherein 70% v / v diesel fuel is blended with 30% v / v biodiesel fuel comprising fatty acid methyl esters.

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