KR101353895B1 - Method of making biodiesel with good low-temperature performance from palm oil - Google Patents

Abstract

The present invention relates to a method for producing biodiesel having good low temperature fluidity from palm oil, and more specifically, C16 palm biodiesel (or C16 palm fatty acid) by distilling palm biodiesel (or palm fatty acid) prepared from palm oil. And C18 palm biodiesel (or C18 palm fatty acid), hydrogenated C16 palm biodiesel (or C16 palm fatty acid) with low temperature fluidity, and converted into a C15 / C16 paraffin mixture to be used as a gas oil blend. It is about.

Vegetable oil, rapeseed oil, soybean oil, palm oil, biodiesel, fatty acid, ester, paraffin, filter plugging point, pour point, hydrolysis, hydrogenation, diesel oil, blended material, low temperature fluidity

Description

Method of making biodiesel with good low temperature fluidity from palm oil {Method of making biodiesel with good low-temperature performance from palm oil}

1 is a domestic biodiesel production process using soybean oil

2 is a flow chart of biodiesel having good low temperature fluidity using palm oil.

3 is a block diagram of a hydrogenation reaction test apparatus of C16 palm fatty acid.

FIG. 4 is a graph showing filter plugging points according to diesel fuel mixing ratios of C16 palm biodiesel and C15 / C16 n-paraffin mixtures.

Figure 5 is a graph showing the price trend by plant classification.

The present invention relates to a method for producing biodiesel having good low temperature fluidity from palm oil, and more specifically, palm biodiesel (or palm fatty acid) prepared from palm oil may be C16 palm biodiesel (or C16 palm fatty acid) and C18. Separation to palm biodiesel (or C18 palm fatty acid), C16 palm biodiesel (or C16 palm fatty acid) having low temperature fluidity is hydrogenated to convert to a paraffin mixture to use as a gas oil blend.

Biodiesel is a fatty acid methyl ester produced by transesterification of vegetable oil (triglyceride) to methanol under a base catalyst. It can reduce emissions of carbon monoxide, nitrogen oxides, fine dust, and carbon dioxide. There is a growing interest as an alternative.

Currently, the raw material of domestic biodiesel is imported soybean oil or recovered oil containing most of soybean oil. As shown in FIG. 5, soybean oil price is cheaper than rapeseed oil, but is usually 20-25% higher than palm oil.

Therefore, palm biodiesel made from palm oil is the most advantageous in terms of production cost, but palm biodiesel has a problem that it is difficult to be used in winter due to low temperature fluidity. Among the components of biodiesel, methyl palmitate (C16: 0) and methyl stearate (C18: 0) deteriorate low temperature fluidity. The percentage is higher than biodiesel made from other vegetable oils.

 Proportion of Biodiesel by Plant Oil Pour Point,
℃ Rapeseed
Bio
diesel Big head
Bio
diesel Palm
Bio
diesel C16: 0 (Methyl Palmitate) 30-32 6% 11% 44.0% C18: 0 (Methyl Stearate) 37-41 1.9% 4 % 4.5% C18: 1 (Methyl Oleate) -20 62.1% 24% 39.2% C18: 2 (Methyl Linoleate) -35 20.2% 54% 10.1% C18: 3 (Methyl Linoenate) -57 8.5% 7% 0.4%

A simple notation of fatty acids such as C18: 1 or C18: 2 shown in the table above, for example, C18: 2 has 18 carbons and 2 unsaturated bonds in the carbon chain. It is present.

 Main Properties of Biodiesel by Plant Type European standard Rapeseed
Biodiesel Big head
Biodiesel Palm
Biodiesel Iodine, g / 100 g <120 98 129 55 Pour point, ℃ <0
(Domestic standard) -12 -2 13 10% residual carbon, wt% <0.30 0.25 0.65 0.10 Oxidation Stability, hr > 6.0 5.5 3.6 6.9 Cetanean > 51 58 50 65

As shown in Tables 1 and 2 above, there is a difference in physical properties of biodiesel for each vegetable oil as a difference in the proportion of ingredients constituting the vegetable oil. Soybean biodiesel contains methyl linoleate (18: 2), which has good low temperature fluidity but poor oxidation stability.

Of the biodiesel components, methyl oleate (18: 1) is most preferred as a biodiesel component because of its low temperature fluidity and excellent oxidation stability. Therefore, rapeseed biodiesel, whose main component is methyl oleate, is the best in terms of physical properties. However, rapeseed oil is relatively expensive and does not have much trade between countries, so it is not easy to secure stable quantities except in some parts of Europe where rapeseed is produced.

An alternative is palm biodiesel, and unless there is a low temperature fluidity problem as described above, palm biodiesel is most suitable in terms of price and quality in countries where most of biodiesel vegetable oils, such as Korea, must be imported from abroad. .

Regarding the low temperature fluidity of palm biodiesel, US Patent Publication No. 2004-0231234 discloses C18 palm biodiesel having good low temperature fluidity after removing C16 palm biodiesel (C16: 0) by distilling or crystallizing palm biodiesel. (C18: 0, C18: 1, C18: 2, C18: 3) are used as diesel blends, and C18 palm biodiesel has a low pour point and can be used as a by-product as a biodiesel in temperate climates. It is mentioned that the resulting C16 palm biodiesel or C16 palm fatty acid can be sold as Oleo chemicals and used as a raw material for alpha-sulphonated methyl esters.

However, the market size of the above-mentioned oleo compounds is not large enough to absorb both C16 palm biodiesel or C16 palm fatty acid and is already saturated. Therefore, the above-described prior art has a problem that C16 palm biodiesel can be practically applied only when there is a use that can be consumed at an appropriate value or more.

In general, C16 palm biodiesel having a pour point of 30 ° C. significantly lowers the low temperature fluidity of diesel fuel.

Meanwhile, according to US Patent No. 4,992,605, a method of converting vegetable oil into a mixture of C15 / C16 / C17 / C18 n-paraffins through a reactor filled with a CoMo type catalyst at high temperature with hydrogen of high pressure is used as a cetane number improver for diesel. Presented. However, according to this, the pour point of the mixture has a problem that the low-temperature fluidity is higher than the pour point of palm biodiesel above 20 ℃, in particular, C18 palm biodiesel is converted to the C17 / C18 n-paraffin mixture when hydrogenated In this case, the pour point becomes much higher (less than 0 ℃ → 25 ℃).

In addition, C18 palm biodiesel has a disadvantage in that 30 to 40% more hydrogen is consumed in the hydrogenation reaction because unsaturated carbon is included in the carbon chain of fatty acids, compared to C16 palm biodiesel. Because hydrogen prices are high, it is important to reduce the hydrogen consumption as much as possible.

Accordingly, in the present invention, as a result of extensive research in order to solve the above-mentioned problems, palm biodiesel is separated into C16 palm biodiesel and C18 palm biodiesel, and C18 palm biodiesel has good low temperature fluidity and is thus used as a diesel fuel formulation. Although it was judged that it could be used, C16 palm biodiesel, which occupies a large portion of palm biodiesel, was poor in low temperature fluidity, and in-depth investigation was conducted to find out how to use it as a diesel blend. When the reaction is converted into a C15 / C16 paraffin mixture, the fatty acid carbon chain constituting the C16 palm biodiesel has almost no unsaturated bonds, and thus, hydrogen consumption in the hydrogenation reaction is relatively small. It has been found that it can be used as a formulation and the present invention has been completed based on this.

Accordingly, it is an object of the present invention to provide a method for producing biodiesel having good low temperature fluidity from palm oil.

It is another object of the present invention to provide a diesel product comprising the biodiesel (C15 / C16 paraffin mixture).

Manufacturing method according to the present invention for achieving the above object,

a) distilling palm biodiesel (or palm fatty acid) to separate C16 palm biodiesel (or C16 palm fatty acid) and C18 palm biodiesel (or C18 palm fatty acid);

b) hydrolyzing the C16 palm biodiesel to C16 palm fatty acid and methanol; And

c) hydrogenating the C16 palm fatty acid or C16 palm biodiesel of step a) to convert to C15 / C16 paraffin mixture.

The diesel fuel containing the biodiesel according to the present invention for achieving the above another object,

Biodiesel (C15 / C16 paraffin mixture) having good low-temperature fluidity prepared by the above production method is contained in diesel fuel at 2 to 10% by volume.

Hereinafter, the present invention will be described in detail.

The present invention provides a method for producing biodiesel having good low temperature fluidity from palm oil. The production method according to the present invention comprises a) distillation of palm biodiesel (or palm fatty acid) to C16 palm biodiesel (or C16 palm fatty acid) and C18. Separating into palm biodiesel (C18 palm fatty acid); b) hydrolyzing the C16 palm biodiesel to C16 palm fatty acid and methanol; And c) hydrogenating the C16 palm fatty acid or the C16 palm biodiesel of step a) to convert to C15 / C16 paraffin mixture.

Hereinafter will be described in more detail according to each step of the production method of the present invention.

a) distilling palm biodiesel (or palm fatty acid) to separate C16 palm biodiesel (or C16 palm fatty acid) and C18 palm biodiesel (C18 palm fatty acid);

Palm biodiesel (or palm fatty acid) consists mainly of C16: 0 (methyl palmitate or palmitic acid) and C18: 1 (methyl oleate or oleic acid), which can be separated by distillation according to the difference in boiling point. Do. Distillation is carried out at a temperature of 180 to 230 ° C. at a pressure of 5 to 20 torr.

C18 palm biodiesel, which is separated into one component of palm biodiesel, has a similar component ratio to rapeseed biodiesel. Therefore, in terms of physical properties, oxidation stability and 10% residual carbon are slightly better than rapeseed biodiesel. Although slightly disadvantageous, it is equivalent to soybean biodiesel, so even if it is used as a diesel blend, there is no problem in low temperature fluidity.However, in the case of C16 palm biodiesel, as shown in Tables 3 and 4, it is suitable for use as a blend If not, it is hydrolyzed to C16 palm fatty acid and methanol and then hydrogenated C16 palm fatty acid.

C18 palm fatty acid, which is isolated as one component of palm fatty acid, can be converted to C18 palm biodiesel while being esterified with methanol under an acid catalyst.

b) hydrolyzing C16 palm biodiesel to C16 palm fatty acid and methanol;

For hydrolysis, water is mixed at a weight ratio of 1/15 or more relative to C16 palm biodiesel, and then a base catalyst is added at least 0.1% by weight relative to the mixture. At this time, if the addition ratio of water to C16 palm biodiesel is less than 1/15, there is a problem that some fatty acids remain without hydrolysis.

There is no particular limitation on the type of base catalyst, but preferably sodium methoxide may be used.

If the content of the base catalyst is added less than 0.1 wt%, there is a problem that the reaction time required for hydrolysis is too long.

As a result of the hydrolysis, C16 biodiesel is separated into C16 palm fatty acid and methanol, and the methanol is recovered through a vacuum evaporator.

c) hydrogenating the C16 palm fatty acid or the C16 palm biodiesel of step a) to convert to a C15 / C16 paraffin mixture;

In the hydrogenation reaction, C16 palm biodiesel can be converted to a C15 / C16 paraffin mixture by hydrogenation.However, while one molecule of C16 palm biodiesel requires at least four molecules of hydrogen, it can be hydrolyzed to C16 palm fatty acid and methanol. In this case, methanol can be recovered and the C16 palm fatty acid reduces the hydrogen required for hydrogenation to three molecules.

Most of the C16 palm fatty acid is converted into a C15 / C16 paraffin mixture through a hydrogenation reaction. The C18 fatty acid mixture, which is included as an impurity, is converted into a C17 / C18 paraffin component by a hydrogenation reaction, but the amount is very small. .

The hydrogenation reaction was carried out with respect to the catalyst volume in a continuous reactor filled with a CoMo or NiMo catalyst, and the hourly passage drainage (LHSV) of the liquid input of C16 palm biodiesel or C16 palm fatty acid was 2hr ^{- 1} or less, and the volume ratio of hydrogen and liquid input (H ₂ to Oil Ratio) is performed at 3 m3 / kL or more, hydrogen partial pressure is 30 bar or more, and the average temperature (BAT) of the catalyst bed is performed at 330 ° C or more.

Direct hydrogenation of C16 palm biodiesel may also occur under these conditions, in which case the hydrogen consumption will be higher than that of C16 palm fatty acids.

When the volume ratio of hydrogen and liquid input is less than 3, the hydrogen necessary for the reaction cannot be sufficiently supplied, and when the LHSV is 2 hr ^{- 1} or more, the hydrogen partial pressure is 30bar or less, and the BAT is less than 330 ° C, the reaction of converting fatty acids into paraffins is prevented. It will not work smoothly.

The catalyst used for the hydrogenation of C16 palm fatty acid may use both a NiMo catalyst or a CoMo catalyst used for desulfurization of diesel fuel.

Physical properties when converted to n-paraffins are as shown in the following table. As shown in the table below, C16 palm fatty acids are converted to n-C15 and n-C16 through hydrogenation, which have a lower pour point compared to n-C17 and n-C18 converted from C18 palm fatty acids. It can be preferably used as a fuel additive.

Conversion of Palm Oil, Palm Fatty Acids, and Palm Biodiesel to n-paraffins Biodiesel C16: 0 C18: 0 C18: 1 C18: 2 C18: 3 Pour point, ℃ 30-32 37-41 -20 -35 -57 Cetanean 74.5 86.9 55 42.2 22.7 importance 0.852 - 0.879 0.889 0.895 n-paraffin n-C15 n-C16 n-C17 n-C18 Pour point, ℃ 9.9 18 22-24 29.5 Cetanean 95 100 105 110 importance 0.769 0.773 0.777 0.777

 As described above, the n-paraffin mixture converted from C16 palm fatty acid or C16 palm biodiesel can be used in admixture with gas oil without reducing cold flowability.

In general, the diesel fuel for winter season is a mixture of kerosene of 150-250 ° C. in boiling point and light gas oil of 250-360 ° C. in boiling point at a ratio of about 3: 7. When added in this amount, it will generally meet domestic and international standards for cold pour point.

When the C15 / C16 n-paraffin mixture according to the present invention is mixed at 2 to 10% by volume in the automotive diesel, the improvement in low temperature fluidity is more pronounced than when the same amount of C16 palm biodiesel is mixed with diesel. . When the C15 / C16 n-paraffin mixture is mixed in excess of 10% by volume of the diesel, it is not preferable in view of the filter plugging point, which is the basis of low temperature fluidity.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited thereto.

Example

Distillation stage

Composition and physical properties of 3,000 g of palm biodiesel separated from C16 palm biodiesel and C18 palm biodiesel in a ratio of 4: 6 in a distillation apparatus at 10 torr and 185 ° C are shown in the table below.

Composition Ratio of Palm C16 / C18 Biodiesel Boiling Point,
℃ C16 Palm
Biodiesel C18 farm
Biodiesel Palm
Biodiesel C16: 0
(Methyl Palmitate) 338 90.5% 8.1% 43.5% C18: 0
(Methyl Stearate) 352 2.2% 5.9% 4.3% C18: 1 (Methyl Oleate) 349 6.8% 65.9% 39.8% C18: 2
(Methyl Linoleate) 366 0.2% 18.3% 10.2% C18: 3
(Methyl Linolenate) - 0.1% 0.5% 0.3%

Main Properties of Palm C16 / C18 Biodiesel European standard C16 Palm
Biodiesel C18 farm
Biodiesel Palm
Biodiesel Iodine, g / 100 g <120 7 88 55 Pour point, ℃ <0
(Domestic standard) 30 -One 13 10% residual carbon, wt% <0.30 0.05 or less 0.15 0.10 Oxidation Stability, hr > 6.0 > 20 6.0 6.9 Cetanean > 51 72 55 65

Hydrolysis stage

470 g of C16 palm biodiesel, 45 g of water and 1 g of Sodium Metoxide are placed in a 1,000 cc round flask and the round flask is attached to a vacuum evaporator.

The vacuum evaporator is operated for 45 minutes at a temperature of 200 torr in a round flask and a temperature of 60 캜 in a water bath. At this time, the methanol generated during the hydrolysis is removed in a vacuum evaporator, and C16 palm biodiesel is converted to C16 palm fatty acid. Lower the pressure of the vacuum evaporator to 40 torr to remove unreacted water and residual methanol. After depressurizing, the obtained C16 palm fatty acid solution was passed through a paper filter at 50 ° C. to remove the base catalyst.

C16 Palm Biodiesel and C16 Palm Fatty Acid C16 Palm
Biodiesel C18 farm
fatty acid constitutional formula RCOOCH ₃ RCOOH Iodine, g / 100 g below 10 below 10 Acid value, mgKOH / g 0.5 202

Hydrogenation Step

While passing the C16 palm fatty acid (100 cc / hr) and hydrogen (0.5 Nℓ / hr) to the catalytic reactor filled with 100cc of CoMo catalyst as shown in FIG. 3, the average temperature of the catalyst layer was gradually raised to 370 ° C, and then 4 After the hour the liquid product began to collect and the liquid product was collected for a total of 10 hours. Water was separated off from the collected product and the components of the remaining liquid product were analyzed.

Comparison of Hydrogen Reactor Liquid Inputs and Liquid Products Liquid input Liquid products division C16 Palm Fatty Acid C15 / C16
n-paraffin mixture water Volume (weight)
yield 995 cc (850 g)
100% 935 cc (720 g)
84.7% (99 g)
11.6% Composition, wt% Fatty acid mixtures
C16: 0 90.5
C18: 0 2.2
C18: 1 6.8
C18: 2 0.2
C18: 3 0.1 n-paraffin mixture
Lighters 1
n-C15 27
n-C16 62
n-C17 2.5
n-C18 5.5
Heaviers 1.5 importance 0.85 0.77 Pour point, ℃ 30 14 Cetanean 72 98

Impact Assessment for Liquidity Enhancers

When the C16 palm biodiesel and the C15 / C16 n-paraffin mixture were mixed in diesel fuel, the filter clogging points according to the injection concentration of the Wax Anti-settling Flow Improver were measured and compared. The filter plugging point is an important indicator of the low temperature fluidity of diesel oil, and the winter quality standard of domestic refiners is "-20 ℃ or less".

Table 8. Effect of C16 Palm Biodiesel and n-paraffin Mixtures on Performance of Fluid Enhancers

Sample name Diesel fuel mix ratio, v% By fluid concentration
Filter clogging point, ℃ Kerosene reshuffle
Gas oil C16 Palm
Bio
diesel C15 / C16
n-paraffin
mixture liquidity
Enhancer
0 ppm liquidity
Enhancer
600 ppm liquidity
Enhancer
1,000 ppm standard 30 70 0 0 -7 -21 -24 1-1 30 68 2 0 -8 -19 -21 1-2 30 65 5 0 -9 -17 -18 1-3 30 60 10 0 -6 -10 -10 2-1 30 68 0 2 -8 -21 -24 2-2 30 65 0 5 -9 -21 -22 2-3 30 60 0 10 -10 -19 -20

As shown in the table and FIG. 4, in the case of C16 palm biodiesel, even if only 2% is mixed, the filter clogging point is increased to meet the filter clogging criteria (-20 ° C. or lower). It was observed to increase. However, in the case of C15 / C16 n-paraffin mixture, the filter clogging point did not change until it was blended with 5% of diesel oil. Was observed.

As described above, the biodiesel according to the present invention utilizes palm oil which is cheaper than soybean oil, which is a raw material of conventional soybean biodiesel, and can achieve low-temperature fluidity that satisfies domestic and international standards through proper processing thereof. For this reason, it is possible to use the environment more actively.

Claims (5)

a) distilling palm biodiesel to separate C16 palm biodiesel and C18 palm biodiesel; b) hydrolyzing the C16 palm biodiesel to convert to C16 palm fatty acid and methanol; And c) converting the C16 palm fatty acid or the C16 palm biodiesel of step a) into a C15 / C16 paraffin mixture; A method of producing biodiesel having good low temperature fluidity from palm oil, comprising: a. The method of claim 1, wherein the distillation is performed at a temperature of 180 ° C. to 230 ° C. at a pressure of 5 to 20 torr. The method of claim 1, wherein the hydrolysis reaction is characterized in that from the palm oil, characterized in that the water is mixed in a weight ratio of 1/15 or more relative to the C 16 palm biodiesel, and the base catalyst is added at least 0.1% by weight based on the mixture A method for producing biodiesel having good low temperature fluidity. The method of claim 1, wherein the hydrogenation reaction is CoMo based or NiMo catalyst is with respect to the catalyst volume in the filled continuous reactor, C16 Palm biodiesel or C16 palm fatty acid per hour passing through a multiple (LHSV) of the liquid phase inputs is 2 hr ^{- 1} or less , The volume ratio of hydrogen and the liquid input (H ₂ to Oil Ratio) is 3 ㎥ / ㎘ or more, hydrogen partial pressure is more than 30bar, the average temperature (BAT) of the catalyst bed is characterized in that the palm is carried out under the conditions A process for producing biodiesel with good low temperature fluidity from oil. The diesel fuel containing biodiesel characterized in that the biodiesel having good low temperature fluidity prepared according to any one of claims 1 to 4 is contained in diesel fuel at 2 to 10% by volume.

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