RU2349631C1 - Method of preparing fine aqueous emulsion in liquid organic medium - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to the process of preparing a fine nano-sized emulsion of the type "water in liquid fuel", and also "water in oil", and can be used in internal-combustion engines, thermal machines, boilers, ovens, and also in pharmaceuticals and food industry, for example, in the production of moist creams, gels, margarines, where ecofriendly technology watering of a liquid organic base is required. Method consists of mixing the organic phase and aqueous phase with additives or without adding surfactants under the action of UHF of an electromagnetic field. Action of the UHF field is stopped immediately after boiling of the aqueous phase, in this case the temperature of the organic phase remains practically the same. As the aqueous phase, possessing a higher density than the organic, being located at the bottom, the fast heating of the aqueous phase leads to fast boiling, steam from the water get to the organic phase, condense, and form fine emulsion water in organic phase, where the size of the water droplets is from 100 to 400 nm.

EFFECT: method does not require high power of the UHF field, it is effective, economical and safe.

3 cl, 1 ex, 5 dwg

Description

The invention relates to a process for preparing a finely dispersed emulsion of the type "water in liquid fuel or oil" and is intended for use in internal combustion engines, boilers, furnaces, heat engines, as well as in the production of colloidal and flooded polymer dispersions, in the food industry in the production of margarines, creams , beer wort, medical and perfume industry.

The use of fuel emulsified by water is good because water, when burning fuel, plays the role of an inhibitor, that is, a substance that prevents the formation of nitrogen and sulfur oxides during combustion, and thereby reduces the amount of polluting emissions. In addition, when burning an emulsion, the heat transfer of fuel increases due to explosive evaporation of water and its greater heat capacity, which leads to an increase in engine efficiency and thereby reduces fuel consumption.

Known methods and devices for producing fuel emulsions [1, 2, 3]. In these emulsions, the dispersion medium is aqueous, with possible inversion of the emulsion by dilution with the organic phase. The emulsion contains less than 20% by volume of water, and the aqueous phase forms the dispersion medium. The disadvantages of these methods include the fact that in the case of emulsified motor fuels in which the dispersion medium is water, corrosion and accelerated wear of parts of the fuel system of the engine are possible.

A finely dispersed water-in-fuel emulsion is more compatible with parts of the fuel system and engine parts, since the dispersion medium is identical to the fuel medium for which the engine is designed. In addition, the combustion of a finely dispersed emulsion of water in the fuel is preferable, since the rapid evaporation of water droplets dispersed in the fuel significantly improves the dispersion of hydrocarbons in the combustion chamber [4, 5]

Closest to the claimed technical essence is a method of preparing liquid fuel for atomization in a combustion chamber [6], which consists in adding water to the liquid fuel, mixing it, then either the aqueous component of the emulsion or the fuel component is heated. The water component of the emulsion is heated using a microwave field, and the fuel component is heated to temperatures above the boiling point at the pressure in the combustion chamber, after which either the heated emulsion is injected into the combustion chamber, or the fuel component of the emulsion is heated to the temperature of the destruction of the fuel, and then the resulting mixture injected into the combustion chamber.

The disadvantage of this method is that it requires a large microwave power to heat the emulsion to temperatures above 130-350 ° C, which leads to high pressures of 100 atmospheres, and this imposes increased requirements on the materials of the fuel system in order to avoid the danger of ignition outside the combustion chamber.

The objective of the invention is to provide an economical, effective and safe technology for the preparation of a finely dispersed emulsion of the type water in oil or water in fuel, in which the dispersion medium is identical to the medium for which the engine is designed.

The problem is solved as follows.

Water is added to the fuel or oil in a ratio of not more than 1: 2 and is exposed to the microwave field. This ratio is chosen so that the fuel phase does not have time to heat up from the aqueous phase. Since the density of water is higher than the density of fuel or oil, the aqueous phase is below. The microwave field acts simultaneously on the fuel and water phases without preliminary mixing, the aqueous phase quickly heats up to the boiling point, while the organic phase practically does not heat up. Water vapor passing through the organic phase condenses and forms a finely dispersed emulsion of water in the fuel, and the size of the water droplets in the organic phase is 100-400 nm. Large droplets from the emulsion are selected for re-treatment with a microwave field. After that, the emulsion is fed into the combustion chamber. To increase the amount of emulsion water in the organic medium, water containing surfactants is added.

The essence of the proposed method is demonstrated by the following example.

Diesel fuel and distilled water (or in other cases oil and water) were poured into a 100 ml glass container in a ratio of at least 2: 1, (the temperature of the water and fuel was initially 15-20 ° C), since the density of water is higher than the density of the fuel oil, water was at the bottom of the tank. Then, the sample, in which fuel and water were separated into two phases, was irradiated with a 2.4 GHz microwave field in a 20 L resonator with an average field power of 2.4 W / cm ³ .

The microwave field heated only the aqueous phase, the temperature of the organic phase remained practically unchanged. Rapid heating of the aqueous phase led to its rapid boiling, water vapor was driven into the fuel phase and condensed. At the moment of boiling the aqueous phase, the microwave field was turned off, the emulsion was poured into a cuvette with a size of 20 cm ³ , after which the radius of water droplets in a dispersed medium of diesel fuel or liquid paraffin was measured by the method of scattered light correlation spectroscopy described [7].

Distilled water and water with various additives of AOT (surfactant bi (2-ethylhexyl) sulfosacinate) were used as the aqueous phase in diesel fuel. Figure 1 shows the data of the measured average radius R _{cf of} water droplets in diesel fuel depending on time t after irradiation with a microwave field for the following samples: 1 - in pure water, and with AOT concentration in water: 2-3%, 3- one%. Experimental data show that after the termination of the microwave field, the size of water droplets grow within 25 minutes and reach a maximum size of 350 nm. Processing according to a special program of correlation functions made it possible to determine the size distribution of suspended water droplets in a dispersion medium. It turned out that the emulsion initially contained droplets larger than 2000 nm, which were deposited within a few minutes. Stability was maintained with water droplets ranging in size from 300 to 400 nm emulsion for more than 1 hour.

Figure 2 shows the dependence of the measured average radius R _{sr of} water droplets in diesel fuel as a function of time t after irradiation with a microwave field for samples with water drops containing AOT in the amount of 1-0.3% and 2-0.1% in water. During the microwave treatment of these samples, the field did not immediately turn off after boiling water, and diesel fuel was heated to 70 ° C due to convective flows. These data show that the steady size of the droplets of water in the heated fuel is 180 nm.

Figure 3 shows the concentration dependence of the average size of water droplets R _cf with various additives of AOT in diesel fuel, 20 minutes after irradiation with a microwave field.

Measurements of the intensity of scattered matchmaking allow us to judge the concentration of water droplets in diesel fuel. Figure 4 shows the light scattering intensity I (the intensity was measured in photomultiplier photon counts) for the same samples. 3 - in pure water, with a concentration of AOT in water: 1-3%, 2-1%.

The data show that there is an optimal concentration of AOT in water, which is 1%, at this concentration in diesel fuel contains the maximum amount of emulsified water.

The stability of the emulsion depends on the density and viscosity of the organic phase. For vaseline and transformer oil, this method can create a stable emulsion in which nanoscale drops of water do not precipitate for 1 month.

A device for emulsifying water with fuel is shown in Fig.5.

The device contains: 1 - a pan for water, 2 - a container for diesel fuel, 3, 4, 5, 6 - tubes, 7 - a microwave resonator, 8 - a pump, 9 - a sump.

 Diesel fuel or oil is supplied through a tube 3 to a container 2, which is located in the microwave cavity 7, water is supplied through a tube 4 either with additives or without additives to the tray 2 of the container 1. After irradiation of the microwave field, the organic phase is emulsified, then large drops precipitated in the sump 9, and the finished emulsion is discharged through the tube 5. Part of the fuel, together with large drops of water through the tube 6, is fed back to the tank 2 using the pump 8.

The method of emulsifying margarine with water is similar. If necessary, it is possible to preheat the oils and fats that form the basis of margarine in order to reduce viscosity to optimize emulsification conditions.

INFORMATION SOURCES

1. Patent DE 19704874.

2. Patent DD 216863.

3. Patent WO 95/33023 THE REDUCTION OF NITROGEN OXIDES EMISSIONS FROM VEHICULAR DIESEL ENGINES 05/31/1994 US.

4. Patent SAE 890449.

5. Patent SAE 920464.

6. Patent RU 2266470 (Method for preparing liquid fuel for atomization into a combustion chamber) - prototype.

7. Patent RU 2306970, Method for preparing colloidal solutions and device for its implementation.

Claims (3)

1. A method of preparing a finely dispersed emulsion of water in a liquid organic medium, which consists in adding water to the organic medium and exposing it to a microwave field, characterized in that the water and organic medium are taken in a ratio of not more than 1: 2, exposure to the microwave field simultaneously on the organic and aqueous phase until the boiling of the aqueous phase, then this effect is stopped and a finely dispersed nanoscale emulsion is selected. 2. The method according to claim 1, characterized in that the large droplets from the emulsion are fed for re-treatment with a microwave field. 3. The method according to claim 1, characterized in that water containing surfactants is added to the organic medium.

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