RU2635664C1 - Method of producing hydrated fuel - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention describes a method of producing hydrated diesel fuel with the addition of water and an emulsifier by treatment in a vibrocavitational homogenizer with a rotating operating element - rotor with a perforated surface and a stationary operating element - stator, wherein diesel fuel is pre-mixed with the surfactant, which is a high-temperature condensation product of a mixture of vegetable oils and mono- or diethanolamine in an amount of 1.0-1.5 wt %, the resulting mixture is fed into a vibrocavitational homogenizer at a specific consumption of the mixture not more than 2.5 g/cm² of the rotor working surface per second and the peripheral speed of its rotation is not less than 20 m/s, after which an aqueous phase in an amount of 10-20 wt % of the total amount of fuel with surfactant with pre-dissolved carbamide in the aqueous phase in an amount of 30-35 wt %, after which the mixture is fed in a stream to the homogenizer in batches not exceeding 10% per pass with the parameters specified above.

EFFECT: producing stable fuel emulsions resistant to low temperatures.

2 cl, 2 ex, 2 tbl

Description

The invention relates to new fuel emulsions, in which the dispersion medium is hydrocarbon fuel, and the dispersed phase is water, the primary field of application of which is the internal combustion engines of vehicles.

A method is being developed for producing water-fuel emulsions, which are motor fuel, in which the dispersion medium is represented by diesel fuel and various grades of gasoline.

The relevance of obtaining stable water-fuel emulsions and their use is explained by the need to solve the problems of energy conservation and environmental safety during the operation of energy fuel machines.

Numerous experiments have established that water has the following effects on the working process in internal combustion engines (ICE):

- reduces the combustion temperature and the burning rate of the air-fuel mixture;

- inhibits the development of flame oxidation of hydrocarbons;

- accelerates the conversion of the released carbon monoxide into neutral dioxide;

- reduces the content of nitrogen oxides in the exhaust gases;

- evaporating, increases the pressure in the cylinders;

- interacting with the surface of the working chamber, cleans it of carbon deposits by means of microexplosive action;

- increases the completeness of combustion of the air-fuel mixture;

- equalizes the change in torque in the angle of rotation of the engine and thereby contributes to an increase in engine power.

This is associated with numerous attempts to supply water in various ways to the engine cylinders. As indicated in patents US 1701621 and US 4696638, science recognized the ability to produce an initial concentrated emulsion of water with heavy bicarbonate oil and then dilute motor fuel such as gasoline with this emulsion in order to obtain the final fuel composition.

The use of water-fuel emulsions is possible provided that the water-fuel emulsion is stable for 72 hours during the operation of the vehicle, for at least a month - with periodic downtime of the vehicle, or at least 3 months - during storage.

In addition, the water-fuel emulsion should have significantly higher environmental performance compared to clean fuel and preferably lower cost than clean fuel.

The use of surface-active substances (surfactants) is a fairly proven approach to obtaining effective emulsifying systems and water-fuel emulsions. Currently, there are many surfactant compositions intended for use in the food and cosmetic industries, as well as in the production of detergents. Some of them are also used to obtain water-fuel emulsions. In addition, there are patents in which emulsions are designed specifically for use as motor fuel. Examples are US patents: 1498340; 1,533,158; 1,701,691; 3,587,581; 3807973; 3,876,391; 4,199,316; 4,244,702; 4696638, in which surfactants include any emulsifier or mixture of emulsifiers used in the art. In more detail, US Pat. No. 3,527,581 describes a water emulsion in gasoline. The surfactant mixture used consists of at least two components, one of which is dissolved mainly in water, the other in the hydrocarbon phase. As a surfactant, a mixture of C12-C20 fatty acids, amines, C3-C5 alkylamino alcohols and C8-C12 alkyl phenols in the alkyl group is used. US patent 3807973 contains a surfactant - fatty acid diethanolamide, triethanolamine monoester and triethanolamine fatty acid and triethanolamine fatty acids.

Other patents include the following. Patent SU 699005 contains a surfactant - a mixture of pentaerythritol diester and oleic acid with polyethylene glycol ether of anhydrosorbate and oleic acid or with tetraethylene glycol ether of isooctyl phenol.

From patent RU 2213768 a method for preparing an emulsifier for producing water-fuel emulsions by mixing a surfactant with water is known, the resulting mixture is heated to a temperature not exceeding 90 ° C, followed by stirring in an apparatus using the principle of an electromagnetic vortex layer of ferromagnetic elements at a speed a magnetic field of 1400-3000 rpm and an energy intensity of 2-5 kW / dm ³ in the working area. There are options for mixing surfactants with aliphatic alcohol.

Patent No. 2365618 describes a water-fuel emulsion intended for internal combustion engines operating on liquid hydrocarbon fuel.

A method of obtaining a water-fuel emulsion consists in mixing a dispersion medium — hydrocarbon fuel and a dispersed phase — water. An emulsifying system for producing said water-fuel emulsion comprises: a first group of components, represented by a low molecular weight anionic surfactant and a nonionic surfactant in a ratio of 3: 1 to 6: 1, respectively, a component or mixture of components from the second group represented by water repellent and a high molecular weight surfactant, a substance from the third group selected from betaine, propanol-2, sorbitol, oil distillates, and a substance or mixture of a substance TV from the fourth group, which are oil-compensating agents. EFFECT: obtaining stable water-fuel emulsions for at least 72 hours.

A known method of producing water-based emulsion fuel according to patent No. 2566306 dated October 20, 2015. The method consists in circulating a mixture of hydrocarbons with water through a vibrocavitation homogenizer at least three times with a relative centrifugal acceleration of the rotor of at least 1200 g and a gap between the rotor and stator of not more than 0.25 mm .

The closest in technical essence and taken as a prototype is a method of producing a water-fuel emulsion, comprising mixing fuel, water and a stabilizer-surfactant. Mixing is carried out in the emulsification unit with the same initial mass ratio of fuel and water or excess water with forced circulation of the formed emulsion with the gradual introduction of fuel into it to a predetermined ratio of fuel and water. (RF patent No. 2100413 dated 12/27/1997)

The separation of the emulsion of diesel fuel prepared by the proposed method is not observed for 4 months, a mixture of emulsion and gasoline for 1 month.

The disadvantages of the methods for producing said reverse fuel emulsions include the instability of the obtained emulsion of hydrated fuel at negative temperatures. All known emulsions at low temperatures are destroyed, because in this case, a phase transition of water occurs - it freezes. The surfactant layer is destroyed at the water-fuel interface and upon thawing, the emulsion is stratified into components.

The objective of the invention is to develop a method for producing highly efficient hydrated water-based fuel emulsion with good performance.

The technical result from the use of the invention is the development of methods for producing stable fuel emulsions, resistant to a temperature of -10 ° C.

The problem is solved and the technical result is achieved by using a surfactant obtained by high-temperature condensation of a mixture of vegetable oils and mono- or diethanolamine, as well as carbamide (urea), which together provide an environmentally friendly exhaust gas to obtain highly efficient hydrated fuel. when using fuel, and also make it possible to obtain stable emulsions up to a temperature of -10 ° C.

The developed method for producing hydrated fuel consists in the fact that a high-temperature condensation product of a mixture of vegetable oils and mono- or diethanolamine, which is in the amount of 1.0-1.5 mass, is used as a surfactant. % are pre-mixed with diesel fuel and processed in a vibro-gravity homogenizer with a rotating working element - a rotor with a perforated surface and a stationary working element - stator with a specific mixture flow rate of not more than 2.5 g / cm ² of the rotor working surface per second and its peripheral speed rotation of at least 20 m / s, after which the aqueous phase is introduced into the resulting mixture in an amount of 10-20 mass. % of the total amount of fuel with a surfactant, with previously dissolved in an amount of 30-35 mass. % urea, and the total mixture is fed in stream to the said homogenizer in portions not exceeding 10% in one pass with the above parameters.

For diesel fuel with a low cetane number, simultaneously with a surfactant, it is additionally introduced as a combustion promoter, for example, cyclohexyl nitrate in an amount of 0.05-0.5 mass. %

The procedure for introducing components into the composition in the developed method is due to the need to obtain a high-quality emulsion with a simultaneous reduction in the technological cycle. In addition, urea is a solid crystalline substance and it cannot be introduced into water while water is introduced into diesel fuel (DT), because it is insoluble in non-polar solvents. It is necessary to preliminarily introduce a surfactant into a diesel fuel for its uniform distribution over the volume of the composition.

As a surfactant, a high-temperature condensation product of a mixture of vegetable oils and mono- or diethanolamine is used.

From the literary source "Bulletin of the Voronezh State University, SERIES: CHEMISTRY. BIOLOGY. PHARMACY, 2013, No. 2, pp. 39-41), IE Karpeeva and others" Synthesis of amides of fatty acids of sunflower oil "there is a known method for producing surfactants by high-temperature condensation of a mixture of vegetable oils and mono- or diethanolamine.

Monoethanolamides are obtained by heating triglycerides and monoethanolamine at a molar ratio of 1: 3 for 3 hours at 120-130 ° C. The monoethanolamides obtained at the end of heating contain glycerin (about 10%). Glycerin is a substance widely used in various cosmetics, detergents, and other products as an emollient.

From the patent of the Russian Federation No. 2451666 there is also known a catalytic method for producing alkylolamides from triglycerides of fatty acids and mono- or diethanolamine in the presence of sodium hydroxide.

Get monoethanolamides with the following quality indicators: the content of the basic substance 86.7-87.2 wt. %, monoethanolamine content 0.7-1.0 wt. % glycerol content 10.0-10.5 wt. %

The following are examples of the preparation of hydrated fuel using the developed method.

EXAMPLE 1

Hydrated fuel is prepared as follows. Diesel fuel of grade L or Z is mixed with the product of high-temperature condensation of a mixture of vegetable oils and mono- or diethanolamine, which is taken in an amount of 1.0-1.5 mass. %, the resulting mixture is sent to a vibro-cavitation homogenizer with a rotating working element - a rotor with a perforated surface and a stationary working element - stator at a specific mixture flow rate of 2.5 g / cm ^{2 of the} working surface of the rotor per second and its peripheral speed of rotation of 20 m / s. After processing in a homogenizer, the resulting mixture is introduced into the aqueous phase in an amount of 10-20 mass. % of the total amount of fuel with a surfactant, with previously dissolved in an amount of 30-35 mass. % carbamide.

The total mixture is fed in a stream in portions not exceeding 10% in one pass with the above parameters, the specific consumption of the mixture is 2.5 g / cm ^{2 the} working surface of the rotor per second and the peripheral speed of its rotation of 20 m / s.

Samples of hydrated fuel with a water content of 5.0-30.0%, containing surfactants in an amount of 0.5-2.0%, have been accumulated. Their properties are shown in summary table 1.

The stability of the obtained samples varies significantly and ranges from 1 day to 90 days or more, which allows the synthesis of emulsions with various properties. The most optimal are emulsions of hydrated fuel with a water content of 10-20% and a surfactant content of 1.0-1.5%.

EXAMPLE 2

The method of producing hydrated fuel is similar to example 1.

Samples of hydrated fuel with a water content in the range of 5-30% have been accumulated. In water, the maximum amount (30-35%) of urea was previously dissolved. The resulting samples were tested in a freezer at -10 ° C for 4 days. Hydrated fuel is a white, opaque, oily liquid with a characteristic odor.

The flash point of hydrated fuel (GT) is 2-5 degrees Celsius above the flash point of the original diesel fuel.

The maximum size of water drops in GT before and after exposure at a temperature of -10 degrees Celsius does not exceed 2 microns

The stability of the emulsions has not changed.

The introduction of cyclohexyl nitrate in an amount of up to 1.0% does not affect the properties of such emulsions. (M.O. Lerner. Chemical regulators of the combustion of motor fuels, Moscow, ed. Chemistry, 1979)

In preliminary tests, the performance of the 2CH8.5 / 11 engine was tested while working on hydrated fuel of various formulations. In all modes, including during hot starts, the engine worked stably.

The use of compositions with tested formulations can reduce the specific effective fuel consumption of up to 15% by weight.

The use of hydrated fuel with tested formulations can significantly improve the environmental characteristics of a diesel installation, a particularly significant effect is observed in reducing the emission of nitrogen oxides (up to 45%).

Claims (2)

1. A method of producing hydrated fuel based on diesel fuel with the addition of water and an emulsifier by processing in a vibro-cavitation homogenizer with a rotating working element-rotor with a perforated surface and a stationary working element-stator, characterized in that diesel fuel is pre-mixed with a surfactant surfactant representing the product of high temperature condensation of a mixture of vegetable oils and mono - or diethanolamine in an amount of 1.0-1.5 mass. %, the resulting mixture is fed into a vibro-cavitation homogenizer with a specific mixture consumption of not more than 2.5 g / cm ^{2 of the} working surface of the rotor per second and a peripheral speed of rotation of at least 20 m / s, after which the aqueous phase is introduced in the amount of 10- 20 mass. % of the total amount of fuel with a surfactant, with urea pre-dissolved in the won phase in an amount of 30-35 mass. %, after which the mixture is fed in a stream to the said homogenizer in batches not exceeding 10% in one pass with the above parameters. 2. The method of producing hydrated fuel according to claim 1, characterized in that for diesel fuel with a low cetane number, simultaneously with a surfactant, cyclohexyl nitrate is additionally introduced as a combustion promoter in an amount of 0.05-0.5 mass. %