RU2571114C1 - Method of producing biofuel - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: biofuel is obtained by neutralising plant oil fatty acids with an alkaline solution to obtain fatty acid salts, wherein the fatty acid salts are treated with oleum in ratio of 2:1, in the presence of jet steam at 90°C; fatty acids are separated from acidic water, rewashed with water to pH 6-7 and mixed with spent glycolic brake fuel in ratio of (8-9):(2-1).

EFFECT: obtaining biofuel with low cost and improved quality properties from industrial wastes and wider range of biofuels.

7 ex, 2 tbl

Description

The invention relates to the production of biofuels, the disposal of industrial waste, expanding the range of biofuels and can be used in the production of environmentally friendly biofuels for industrial and domestic needs.

It is known to obtain biodiesel fuel based on rapeseed oil for use in automotive engines (Ablaev A.R. Production and use of biodiesel: a reference manual / A.R. Ablaev et al. - M .: APK and PPRO, 2006. - 31 p.) in which methanol is used to neutralize rapeseed oil fatty acids.

The disadvantage of this method is the use of methanol, which is a strong poison, explosive and flammable substance, the use of only rapeseed oil and the presence of unused waste oil purification - salts of fatty acids.

The closest is the method of biofuel production based on rapeseed oil for diesel tractor engines (RF patent No. 2393209, С11С 3/04, 2010), including the neutralization of rapeseed oil fatty acids with a 20% potassium hydroxide solution, which is added in an amount of 0, 25% of the oil volume. Refined rapeseed oil is mixed with diesel fuel in a ratio of 2.5: 1, respectively.

The disadvantage of this method is the use of only rapeseed oil, expensive diesel fuel and the presence of unused waste oil cleaning - salts of fatty acids, and as a result, the high cost of the resulting fuel.

The objective of the proposed technical solution is to reduce the cost of biofuels through the use of industrial waste.

The technical result is the production of biofuels with low cost and high quality indicators from industrial waste.

The technical result is achieved due to the fact that after neutralizing the fatty acids of the vegetable oil with an alkaline solution, the obtained salts of fatty acids are treated with oleum in a ratio of 2: 1, respectively, in the presence of acute water vapor at a temperature of 90 ° C, fatty acids are separated from acidic water, washed again water to a pH of 6-7 and mixed with spent glycol brake fluid in the ratio (8-9) :( 2-1).

Distinctive features of the invention are: the treatment of alkaline salts of fatty acids with oleum under given conditions and the mixing of brake fluid with the resulting fatty acids.

One of the stages of obtaining vegetable oils is the purification of oil from free fatty acids by alkaline neutralization. In the process of purification, alkali metal salts of fatty acids (sodium or potassium carboxylates), which is a waste product, precipitate. Fatty acids have a fairly high calorific value, low viscosity and in a mixture with other components can be used as biofuels. To obtain them, the treatment of an alkali metal carboxylate with high concentration of sulfuric acid under the proposed conditions is proposed.

Brake fluids used in automobiles are mono- and polyglycols and their esters with the addition of anticorrosive, antioxidant, antifoam additives and plasticizers. They are hygroscopic. With the absorption of water, their properties deteriorate: the boiling point decreases, the viscosity increases, the lubricity of automobile parts deteriorates, and the corrosion of metals intensifies. Glycolic brake fluids accumulate up to 2-3% of water per year and they need to be changed. The frequency of replacement depending on the operation of the car is usually from 1 to 3 years. Their disposal is problematic.

A mixture of fatty acids with spent glycol liquids in the stated ratio allows you to get biofuels for industrial and domestic needs.

Thus, the set of essential features set forth in the claims provides the desired technical result, namely, the production of biofuels with low cost and high quality indicators from industrial waste.

Biofuels are obtained by mixing fatty acids with spent glycol brake fluid at a temperature of 40-45 ° C in the ratio (8-9) :( 2-1), respectively, until a stable homogeneous fluid is obtained.

Fatty acids are obtained from alkali metal carboxylates, which are a waste in the production of vegetable oils. Alkali metal carboxylates are treated with oleum in a ratio of 2: 1, respectively, at a temperature of 90 ° C for 20-25 minutes. Mixing the mixture and temperature ensures the supply of sharp water vapor with a temperature of 120 ° C. The resulting fatty acids are separated by decantation from acidic water and washed with water to a pH of 6-7. Acidic waters are neutralized with a solution of caustic soda.

The following are examples of biofuels.

The experiments were carried out in laboratory conditions. In the work, an enameled autoclave with a capacity of 20 l was used, equipped with fittings for supplying water vapor, water, draining acidic water and a sealed lid for loading components. The biofuel components were mixed in a 5 L apparatus equipped with a high-speed stirrer (up to 3000 rpm) and heated, providing a temperature of 40-45 ° C. Mixing time 30-40 minutes

The sodium salt of fatty acids (sodium carboxylate), which is a waste of the production of sunflower oil, was taken to OJSC "Yugmasloproduct", Kropotkin, Krasnodar Territory.

The resulting biofuel was determined by the conditional viscosity VZ.4 according to GOST 8420, the heat of combustion according to GOST 21261, the mass fraction of sulfur according to GOST P51947, the content of solids according to GOST 6370.

Example No. 1

2 kg of sodium carboxylate was placed in an autoclave, 1 kg of oleum was added thereto, the lid was tightly closed and superheated water vapor was supplied at a temperature of 120 ° C. When the temperature in the autoclave reached 90 ° C, the treatment of sodium carboxylate was continued for 23 minutes, the steam was turned off, the autoclave was cooled to 40 ° C and acidic water was drained. Then, 10 l of tap water was fed twice. Waste water was determined by pH. The processing conditions and the yield of fatty acids are presented in table No. 1.

1.7 kg of fatty acids (FA) and 0.3 kg of spent glycol brake fluid (TFA) were placed in an apparatus equipped with a high-speed stirrer and heating. With constant stirring, the mixture was heated to 42 ° C and stirred for another 35 minutes.

The resulting biofuel was analyzed, the results are presented in table No. 2.

Example No. 2

The method of producing biofuel is carried out according to example No. 1 with the difference that the processing of sodium carboxylate was carried out for 20 minutes. To mix the components, 1.8 kg of FA and 0.2 kg of TJ were taken, the mixture was heated to 40 ° C and stirred for 40 minutes.

The results of the experiment are presented in tables No. 1, 2.

Example No. 3

The method of obtaining biofuels is carried out according to example No. 1 with the difference that the processing of sodium carboxylate was carried out for 25 minutes. To mix the components, 1.6 kg of FA and 0.4 kg of TJ were taken, the mixture was heated to 45 ° C and stirred for 30 minutes.

The results of the experiment are presented in tables No. 1, 2.

Example No. 4 (comparative)

The method of producing biofuel is carried out according to example No. 1 with the difference that 0.8 kg of oleum was taken for processing sodium carboxylate, the treatment was carried out for 23 minutes. 1.9 kg of FA and 0.1 kg of TFA were taken to mix the components, the mixture was heated to 45 ° C and stirred for 30 minutes.

The results of the experiment are presented in tables No. 1, 2.

Example No. 5 (comparative)

The method of producing biofuel is carried out according to example No. 1 with the difference that 1.2 kg of oleum was taken for processing sodium carboxylate, the treatment was carried out for 23 minutes.

The results of the experiment are presented in tables No. 1, 2.

Example No. 6 (comparative)

The method of producing biofuels is carried out according to example No. 1 with the difference that the processing of sodium carboxylate with oleum was carried out at 85 ° C for 23 minutes.

The results of the experiment are presented in tables No. 1, 2.

Example No. 7 (comparative)

The method of producing biofuel is carried out according to example No. 1 with the difference that the processing of sodium carboxylate with oleum was carried out at 95 ° C for 23 minutes.

The results of the experiment are presented in tables No. 1, 2.

As can be seen from the presented results, the claimed ratio of salts of fatty acids to oleum, temperature and processing time provide a high yield of fatty acids (pr. No. 1-3, table. 1). When reducing the ratio of salts of fatty acids to oleum or lowering the processing temperature (pr. No. 4, 6, table. 1), it is necessary to increase the contact time to achieve a high yield of fatty acids. An increase in the ratio of salts of fatty acids to oleum and an increase in the processing temperature (pr. No. 5, 7, table. 1) do not increase the yield of fatty acids, moreover, an increase in oleum leads to an increase in the amount of washing water to achieve a neutral pH.

The quality of the obtained biofuel after mixing fatty acids with spent glycol brake fluid is presented in table No. 2. Biofuel meets the standards for fuels, and in terms of such indicators as the mass fraction of sulfur and the content of solids exceeds the requirements of existing standards. However, with a decrease in the declared amount of spent glycol brake fluid in biofuel, the calorific value of biofuel decreases (pr. No. 4).

Thus, the proposed solution provides biofuels with low cost and high quality indicators from industrial waste and expands the range of biofuels.

Claims (1)

A method of producing biofuels, including the neutralization of fatty acids of vegetable oil with an alkaline solution to obtain salts of fatty acids, characterized in that the salts of fatty acids are treated with oleum in a ratio of 2: 1, respectively, in the presence of sharp water vapor at a temperature of 90 ° C, the fatty acids are separated from acidic water , repeatedly washed with water to a pH of 6-7 and mixed with spent glycol brake fluid in the ratio (8-9) :( 2-1).