DE3042124A1 - FUEL EMULSIONS AND METHOD FOR THEIR PRODUCTION - Google Patents

Description

Diesel fuel emulsions and processes for their preparation

The invention relates to new diesel fuel emulsions and a process for their preparation, in particular on water-in-oil emulsions, which are a diesel fuel, comprise an alcohol, water and an emulsifier.

The use of substitute fuels to reduce the Consumption of crude oil has gained considerable importance in recent years. Research work in this area was directed in particular to gasoline engines or engines with ignition by spark plugs. There is an attractive solution in the use of mixtures of gasoline and alcohols; Methanol and ethanol can work with gasoline in all proportions are mixed and have a high octane number (about 87 to 90).

130024 / 072S

However, the incorporation of alcohols into diesel fuels creates some difficulties. As is well known, the trouble-free running of diesel engines (or engines with spontaneous ignition) requires the use of fuels with a cetane number of at least 26. But the cetane numbers of methanol and ethanol are low (3 and 8 respectively), and the cetane number of a diesel fuel, in particular
of gas oil and light heating oil, is between 34 and 55. Therefore, the range of mixtures with a diesel fuel and alcohol that show a suitable cetane number is
relatively small. Also are methanol and ethanol
Practically immiscible with diesel fuel, and mixtures of these components cannot be prepared beforehand. The only solution proposed is to use a bimodal delivery system. Such a system requires mechanical modifications, ie two tanks, a monitoring or control device for the "alcohol"
etc.

The invention aims to create diesel fuel emulsions, who overcome this deficiency. It should also be stable substitute fuels with a suitable cetane number as well as water-in-oil emulsions with a diesel fuel and an alcohol. Furthermore, it should also become a Process for the preparation of these emulsions lead.

The combustible water-in-oil emulsions of the present invention include

97 to 90 vol .-% of a mixture, which is a major proportion of

a diesel fuel from the gas oil and light group Contains heating oil and a smaller amount of an aqueous solution of methanol and / or ethanol, and.

3 to 10% by volume of an emulsifying mixture, the sorbitan monooleate and contains a water-soluble, non-ionic, ethoxylated surfactant.

130024 / 072S

According to one embodiment of the invention, in which gas oil as Diesel fuel is used, the emulsion comprises 55 to 92 vol .-% gas oil, 5 to 35 vol .-% of an aqueous alcohol solution, wherein the volume percentage of water in the solution is between 43 + 0.20 S and 74, where S is the Volume percentage of ethanol based on the total volume of alcohol, and 3 to 10 volume% emulsifying Mixture on.

According to a further embodiment, in which light heating oil is used as diesel fuel, the emulsion has 45 to 92% by volume of light fuel oil, 5 to 45% by volume of an aqueous alcohol solution, the percentage by volume being Water in the solution is between 45.7 + 0.229 S and 74.3, where S is the percentage by volume of ethanol based on the total volume of alcohol, and 3 to 10% by volume emulsifying mixture.

The alcohol is preferably methanol and / or ethanol. These alcohols may contain a small amount of another aliphatic Low molecular weight alcohol or a denaturant such as methyl ethyl ketone. Thus, denatured alcohols, which generally contain up to 3% denaturing agent, in the invention Agents or emulsions are used.

These new agents are stable water-in-oil emulsions that have low viscosity and a suitable cetane number. Therefore, they can be used as substitute fuels for diesel engines and for heating purposes. Furthermore, they are stable and do not give rise to segregation and settling of water in the bottom of the container, the settling of Water is a serious problem and this water would be injected into the prime mover or the burner first and would lead to a standstill. The term "stable emulsion" is intended to mean that there is practically none for at least 72 hours

130024/0725

Segregation occurs; a ring made of diesel fuel can however, occur insofar as the amount of segregated fuel is not greater than 3% by volume of that present in the emulsion Fuel. In the event of separation, the emulsion can easily be restored by stirring.

The stability of the emulsions according to the invention depends on many factors, such as the type of diesel fuel, the type and amount of the emulsifying agent, the hydrophilic / lipophilic Equilibrium '(hIG value) of the emulsifying mixture, the respective amounts of alcohol and Water, the type of alcohol, the type of manufacture.

If the emulsion is used for diesel engines, the maximum amount of the aqueous solution of the alcohol in the emulsion is determined with regard to the cetane number. It Amounts of aqueous solution up to 45% by volume can be used, but in general emulsions are no more more suitable than 40% by volume aqueous alcohol solution if the diesel fuel is light heating oil.

If the emulsion is made from gas oil, the The amount of aqueous alcohol solution generally does not exceed 35% by volume. If the emulsions for heating purposes are used, the calorific value is the main limiting factor, and emulsions up to 45% by volume are aqueous Alcohol solutions can be used. On the other hand, there are emulsions containing an aqueous alcohol solution below 5% by volume not very attractive as the fuel saving is negligible.

The hIG value of the emulsifying mixture also plays a role in the stability of the emulsion. Preferably the The hIG value of the emulsifying mixture is at least 5, but generally does not go beyond about 7 when the The emulsifying fuel is light heating oil, or in the case of gas oil even about 6.5. The type of emulsifying mixture

130024/0725

is also another factor, and the mixture preferably contains sorbitan monooleate together with a water-soluble, non-ionic, ethoxylated surfactant. Examples of surfactants are ethoxylated sorbitan monooleate with 20 up to 40 moles of ethylene oxide (or ÄO), ethoxylated sorbitan monolaurate with 11 to 40 AO, ethoxylated nonylphenol with 8 to 50 AO, ethoxylated fatty alcohols with 6 to 50 AO, Polyethylene glycol monooleate with a molecular weight between about 480 and 1200. The choice of surfactant depends on some factors such as availability, price and effectiveness. The stability of the emulsion also depends on the type of fuel to be emulsified, e.g. Emulsions made from gas oil are more stable than similar emulsions made from light fuel oil when ethoxylated Fatty alcohols can be used as surfactants.

The required hIG value can be determined by varying the respective Amounts of sorbitan monooleate and surfactant can be achieved. The quantities to be used are by the experienced skilled worker easy to determine.

The stability of the emulsion also depends on the proportion of water in the aqueous alcohol solution. This share varies with the type of alcohol (methanol, ethanol or their mixtures) and the type of fuel to be emulsified. For the production of emulsions based on light heating oil, the volume percentage of water is in of the aqueous solution generally between 45.7 + 0.229 S and 74.3, where S is the percentage by volume of ethanol on the total volume of alcohol, is. For gas oil based emulsions, the volume percentage of water is in the aqueous solution generally between 43 + 0.20 S and 74. Aqueous alcohol solutions with outside amounts of water these limit values are generally less suitable for the production of stable emulsions.

130024/0725

That to be used for the preparation of the emulsions according to the invention It has been found that the process has an influence on the stability of the emulsion. After another Emulsions are an embodiment of the invention produced by a process in which i) first a mixture of diesel fuel and emulsifying mixture, ii) the aqueous solution of the alcohol is prepared and iii) the aqueous solution is added to the first mixture with stirring will. Other manufacturing methods have certain disadvantages. For example, the addition of the first results Mixing with the aqueous alcohol solution results in less stable emulsions. The addition of separate streams of water and Alcohol to the first mixture requires the use of high-shear stirrers, which increases the temperature of the Mixture and some evaporation of the alcohol with it.

To further illustrate the invention the following non-limiting examples are given:

example 1

Various emulsions were prepared by adding an aqueous solution of 15 cm ^{3 of} methanol and 20 cm ^{3 of} water with stirring to a mixture of 61 cm ^{3 of} light heating oil and 4 cm ^{3 of an} emulsifying mixture.

The emulsifying mixtures were as follows:

A: Sorbitan monooleate + ethoxylated sorbitan monooleate

(20 ÄO)
3: Sorbitan monooleate + ethoxylated sorbitan monolaurate (20 ÄO)

C: Sorbitan monooleate + polyethylene glycol monooleate (MW 600) D: sorbitan monooleate + ethoxylated nony! Phenol (15 ÄO)

130024/0726

The hIG values of these mixtures were between 4.3 and 8.5. These different hIG values were obtained by varying the respective amounts of the ingredients in these mixtures.

The stability of the emulsions obtained was after 96 h their manufacture determined. The results are shown in Table 1 below:

Table 1

Emulsify-
of the mixture 4.3 hlG index
5 5.5 6 6.5 7 7.5 8 8.5 A. + _{++ ++ ++ ++ ++ +} - B. + ++ ++ ++ ++ ++ + - C. + ++ ++ ++ ++ ++ + - D. ⁺ _{++ ++ ++ ++ ++} + -

(++: stable; +: partial separation; -: complete separation)

The following emulsifying mixtures were used for comparison:

X: polyethylene glycol monooleate (MW 200) + polyethylene glycol monooleate (MG 600)

Υ: ethoxylated fatty alcohol (2 ÄO) + ethoxylated Fatty alcohol (5 AO)

Various mixtures were prepared, the respective amounts of surfactants were adjusted so that they one covered a wide range of hIG values. With these mixtures emulsions were made but they were not stable.

130024/0725

Example 2

The procedure described in Example 1 was used to prepare emulsions with various contents emulsifying mixtures and various hIG values repeated.

The total volume of each emulsion was 100 cm ³ and the compositions were as follows:

Methanol: 15 cm ^3, water: 20 cm ³

emulsifying mixture: 1 to 10 cm ³ (mixture A of Example 1) light heating oil: 55 to 64 cm ³

The results of the stability tests were as follows (Table 2):

Table 2

hlG emulsifying mixture (Vol. -%) 1 0 12 3 4 5 6 8th + + 5 - _{++ ++} + + ++ _{+ +} + + 5.5 + ++ + + + + 6th + ++ ++ + + 6.5 + ++ ++ + + 7th + ++ ++

(++: stable after 96 h; -: segregation)

The same results were obtained using emulsifying mixtures B and C described in Example 1.

T30024 / 072S

Example 3

^{An aqueous solution containing 15 cm 3 of} methanol and 20 cm ^{3 of} water was added to a stirred mixture of 61 cm ^{3 of} light heating oil and 4 cm ^{3 of} emulsifying mixture A (hIG = 6).

The emulsion obtained was stable after 96 hours.

Another part of this emulsion was cooled 96 hours at -2O ⁰ C; he remained stable.

For comparison, the same amounts of ingredients were used, but a different procedure was used:

a) Separate streams of methanol and water were added to the stirred mixture of fuel and emulsifying mixture given: after 72 h complete separation had occurred;

b) a mixture of fuel and emulsifying mixture was added to the stirred aqueous methanol solution: complete separation after 24 hours.

Example 4

Different emulsions were made with different amounts of methanol and water, but the total volume of Methanol + water was the same in each emulsion.

The emulsifying mixture (mixture A of example 1). would have a hlG value. from 6.

The compositions (in% by volume) of the emulsions and the results of the stability tests are summarized in Table 3.

130024/0725

4th 4th 4th 4th 4th 4th 4th 4th 8th 7th 8th 9 16 17th 18th 19th 20th 20th 28 27 26th 19th 18th 17th 16 15th 15th

Table 3

Light heating oil 61 61 61 61 61 61 61 61

emulsifying mixture

Methanol water

Stability - ++ ++ ++ ++ ++ -

Example 5

Different emulsions have been made with different amounts of light fuel oil. For each emulsion was that Amount of water in the aqueous methanol solution 57.1% by volume.

The emulsifying mixture (Mixture A of Example 1) had an hlG value of 6.

The compositions (in% by volume) of the emulsions and the results of the stability tests are given in Table 4.

Light heating oil

emulsifying mixture

Methanol + water stability

Example 6

Various mixtures were ^{prepared from 61 cm 3 of} light fuel oil and 4 cm ³ each of the emulsifying mixtures A to D of Example 1. The hIG values of these mixtures ranged from 4.3 to 8.5.

An aqueous ethanol solution was made from 25% by volume of water and 10% by volume of ethanol.

130024/0725

Tabel 4th 71 51 1 81 4th 4th 4th 4th 25th 45 5 15th

The procedure described in Example 1 was used to prepare the emulsions; the total volume of each emulsion was 100 cm ³ .

The results of the stability tests (after 96 hours) are shown in Table 5.

Table 5

emulsifying
mixture hlG
4.3 5 5.5 6 6.5 7 7.5 8 8.5 A.
B.
C.
D. - ♦♦ ♦♦ «♦♦ ♦♦ - -. - ·

Example 7

Various emulsions were prepared from light heating oil, emulsifying mixture A of Example 1 (HIG: 5 to 7), water and ethanol. The total volume of each emulsion was 100 cm ³ . The emulsions contained 25 cm ^{3 of} water, 10 cm ^{3 of} ethanol, 1 to 10 cm ^{3 of} emulsifying mixture and 54 to 64 cm ^{3 of} fuel each.

The stability results are given in Table 6:

130024 / 072S

Table 6

hlG emulsifying mixture (Vol.- ?;) 12 3 4 5 6 8

Example 8

Various emulsions were made from light fuel oil, emulsifying Mixture A of Example 1 (hIG = 7) and an aqueous ethanol solution (% by volume of water: 73.4).

The compositions (% by volume) and results of the stability tests are given in Table 7:

91 Table 7 71 51 light heating oil 4th 81 4th 4th emulsifying
mixture 5 4th 25th 45 aqueous ethanol
solution ++ 15th ++ ++ stability ++ Example 9

Various emulsions were made with aqueous solutions containing methanol and ethanol.

The table shows the respective volumes of the constituents and the results of the stability tests

130024/0725

Table 8

attempt

light heating oil 61

emu! greedy Mixture A (hIG = 7) methanol ethanol water stability

16.6

0.9

[17.5

61

14.0 1.75 19.25

61

14.0 3.5 17.5!

61

10.5 1.75 22.75

61

4 7

3.5 24.5

26.25

61

1.75 8.75

24.5

61

3.5 10.5 21

Experiments 3 and 8 are comparative experiments. The amount of water is less than the minimum required. In experiment 3, the amount of water in the aqueous alcohol solution is 50% and the minimum amount should be 45.7 + (0/229 χ 20) or 50.28%. In experiment 8, the amount of water is in the
aqueous alcohol solution 60%, and the minimum amount should be 45.7 + (0.229 χ 75) or 62.87%.

Example 10

Various emulsions were made. A mixture of 36 cm ^{3 of} methanol and 16 cm ^{3 was used for each emulsion}
Water was added with stirring to a mixture with 64 cm ^{3 of} gas oil and 4 cm ^{3 of} emulsifying mixture. The emulsifying mixtures used were mixtures A to D of Example 1 and mixture E with sorbxtan monooleate and ethoxylated fatty alcohol (9 AO). The hIG values of these mixtures (from 5 to 12) were obtained by varying the respective amounts of the ingredients.

The results are shown in Table 9:

130024/0725

- 16 Table 9

Emulsifying agent
mixture 5 5.5 6th .hlG
6.5 7 8th 10 12 A. ₊₊ . ₊₊ ++ ₊₊ + - - - B. f ++ ++ ++ + - - - C. f ++ ++ ++ + - " - - D. ++ ++ ++ ++ + - - - E. f ++ ++ ·: ■ ++ + - -

(++: stable after 96 h; +: partial separation; -: complete separation).

For comparison, the following emulsifying mixtures were used to make similar emulsions.

F: sorbitan monooleate + polyethylene glycol monooleate (MG: 300) (not soluble in water)

G: Sorbitan monooleate + ethoxylated nonylphenol (4 ÄO) (insoluble)

H: sorbitan monooleate + ethoxylated fatty alcohol (3 ÄO) (insoluble)

I: Sorbitan monolaurate + ethoxylated sorbitan monolaurate (20 AO) (soluble)

J: polyethylene glycol monooleate (MW: 200) + polyethylene glycol monooleate (MG 600) (soluble)

K: ethoxylated nonylphenol (4 ÄO) + ethoxylated nonylphenol (15 ÄO)

L: ethoxylated fatty alcohol (3.ÄO) + ethoxylated fatty alcohol (9 ÄO).

The emulsions made with these emulsifying mixtures were not stable.

130024 / 072S

Example 11

An emulsion was made from gas oil (64% by volume), emulsifying agent Mixture A of Example 1 (4% by volume), methanol (16% by volume) and water (16% by volume) prepared. The cetane number of the Emulsion was 26.

The emulsion was used in a diesel engine.

A road test (80 km) was carried out and the emulsion The consumption was 48.3 1 or the gas oil consumption was 30.9 The same test was carried out on gas oil: the consumption was 39.3 1.

Example 12

Emulsions with various amounts of emulsifying mixture (mixture A; hIG between 5.5 and 6.5) were prepared.

Each emulsion had a total volume of 100 cm ³ . It contained 22.5 cm ^{3 of} water and 12.5 cm ^{3 of} ethanol. The amount of the emulsifying mixture varied between 1 and 10 cm ³ and the amount of gas oil between 55 and 64 cm ³ .

The results of the stability tests are shown in Table 10:

Table 10

repay 1 emulsifying
2 3 mixture
4th (Vol.
5 6th 8th 10 5.5
6th
6.5 - Il ♦♦ ■ + 1-

130024/0725

Claims (6)

Claims 1. Water-in-oil type diesel fuel emulsions with 97 to 90 vol .-% of a mixture with a main amount of conventional diesel fuel and a smaller amount of at least 5% by volume, based on the volume of the emulsion, of an aqueous solution of methanol and / or ethanol and 3 to 10% by volume of an emulsifying mixture of sorbitan monooleate and water soluble ethoxylated nonionic surfactant. 2. Diesel fuel emulsions according to claim 1 with 55 to 92% by volume gas oil, 5 to 35% by volume aqueous methanol and / or ethanol solution, where the volume percentage of water in the solution is between 43 + 0.20 S and 74, where S is the percentage by volume of ethanol, based on the total volume of alcohol, and with 3 to 10 vol .-% emulsifying mixture with an hIG value between 5 and 6.5. 130024/07 25 ORIGINAL INSPECTED 3Q4212A 3. Diesel fuel emulsion according to claim 2, whose surfactant is an ethoxylated sorbitan monooleate with 20 to 40 moles of ethylene oxide, an ethoxylated sorbitan monolaurate with 11 to 40 moles of ethylene oxide, an ethoxylated nonylphenol with '8 to 50 moles of ethylene oxide, an ethoxylated fatty alcohol with 6 to 50 moles of ethylene oxide and / or monooleate of polyethylene glycol with a molecular weight between 480 and 1200. 4. Diesel fuel emulsions according to claim 1 with 45 to 92 vol .-% light fuel oil, 5 to 45 vol .-% of an aqueous solution of methanol and / or ethanol, the The volume percentage of water in the solution is between 45.7 + 0.229 S and 74.3, where S is the volume percentage of ethanol, based on the total volume of alcohol, and with 3 to 10 vol .-% emulsifying mixture with a hlG value between 5 and 7. 5. Diesel fuel emulsions according to claim 4 with an ethoxylated sorbitan monooleate with 20 to. 40 moles of ethylene oxide, an ethoxylated sorbitan monolaurate with 11 to 40 moles of ethylene oxide, an ethoxylated nonylphenol with 8 to 50 moles of ethylene oxide and / or a monooleate of Polyethylene glycol with a molecular weight between 1200 and 1200 as a surfactant. 6. Process for the preparation of the emulsions according to one of the preceding claims, characterized in that the aqueous alcohol solution is added to a mixture of fuel and emulsifying mixture with stirring. 130024 / 072S