RU2685255C1 - Automotive gasoline component and method for production thereof - Google Patents

Abstract

FIELD: technological processes.SUBSTANCE: invention discloses a method of producing a automotive gasoline component, characterized in that after mixing a low-boiling by-product of production of butyl alcohols and light hydrocarbon fractions with an initial boiling point of not lower than 25 °C and a final boiling point of not higher than 250 °C in a weight ratio of components of 0.2:0.8 (low-boiling by-product:light hydrocarbon fraction) water is separated by separation and anticorrosion additive is added in amount of 0.05 wt%. Automotive gasoline component is also disclosed.EFFECT: obtaining automotive gasoline component, which provides improved operational properties of commercial gasolines.2 cl, 1 dwg, 2 tbl, 2 ex

Description

The invention relates to the field of oil refining and petrochemistry, in particular, to obtain, based on the by-products of the synthesis of butyl alcohols, a component of high-octane gasolines intended for use as automobile fuel for internal combustion engines with spark ignition.

In recent decades, there has been a significant increase in the fleet of cars with petrol internal combustion engines. At the same time, vehicle manufacturers, due to the tightening of the requirements of official regulators and competition, are constantly forced to improve the engines of modern cars, increasing their efficiency, which in most cases leads to higher demands on the quality of the fuel used in terms of its knock resistance. This poses a pressing problem for fuel companies to expand the production of high-octane gasolines that meet all modern requirements.

One of the common ways to solve this problem is the use of anti-knock additives that improve the characteristics of commodity fuels and allow using low-octane components to increase the output of gasoline. As such additives, in most cases, various petrochemical products are used, containing nitrogen or oxygen atoms (oxygenates).

Known methyl tert-butyl ether (MTBE), oxygenate widely used as an additive to marketable gasolines in order to increase their octane numbers [USSR Patent No. SU 1838383 A3]. This substance is involved as an antiknock additive, both independently and in combination with other octane enhancers. The method of obtaining MTBE is the direct esterification of olefin with methyl alcohol, the ratio of reagents is 1: 2, respectively (V.M. Kapustin, M.G. Rudin. "Chemistry and technology of oil refining", M., "Chemistry", 2013, p. 445). This method involves the construction and operation of special production used to produce a single target product for a specific purpose, which leads to an increased cost of this additive. At the same time, due to the low boiling point and high pressure of saturated vapors, the use of MTBE may be limited in the production of certain types of automotive gasoline. When storing fuel in the summer periods, the octane number of the fuel may be lost as a result of the evaporation of its fuel, which can also create difficulties in the operation of vehicles.

The patent RU 2209811 is also known (Bulletin No. 22 August 10, 2003, authors: Anichkin A.I., Dobrovinsky A.L., Kolobrodov V.P., Ksenulis Periklis Aristominovich, Maksimov S.V., Pilch L.M., Smirnov V.A., Stryakhileva M.N., Kharitonov N.V., Yablonsky P.O. Patentee (s): Open Joint-Stock Company Research Institute "Yarsintez"), which proposes a method for producing a complex product containing ethanol or methanol and alkyl tert-alkyl esters of C ₄ -C ₇ . In addition to esters and alcohol, it contains unreacted C ₅₊ hydrocarbons. The presence of the latter increases the instability of the product during storage, as well as in the composition of gasoline. The specific efficiency of the product as a high-octane additive decreases, which entails the difficulty of correcting the anti-knock properties of gasolines.

The closest analogue of the invention (prototype) is to obtain an additive to motor gasoline based on Isobutanol, which also involves the involvement in the composition of the fuel composition by-products of the production of butyl alcohols or their mixture with waste to produce 2-ethylhexanol in an amount of 5% by weight. up to 30% wt. [RF patent №RU 2603644 C1]. This patent presents a method of using the by-products of the production of butyl alcohols in the composition of the additive to motor gasoline. The main disadvantage of this composition is that in addition to organic compounds, by-products contain water, which leads to a deterioration in the performance properties of commodity fuels.

The by-products of the production of butyl alcohols are formed at the stage of synthesis, they are separated from the target products by means of a rectification process. High-boiling by-products are discharged as a bottoms residue, while low-boiling by-products are separated as distillates and consist mainly of C ₄ alcohols, light esters and aldehydes. In addition to organic compounds boiling byproduct contains water in an amount of from 1% wt. up to 10 wt.%, not separated in the process of simple distillation due to the azeotropic nature of the mixture.

Water has low solubility in gasolines (71 ppm at 25 ° С [Technical Data Book - Petroleum Refining. - API. 1997]). In this regard, the use of boiling byproduct as a component of motor gasoline leads to turbidity of the final product due to the release of moisture in the form of a separate dispersed phase. This, in turn, leads to a deterioration in the performance properties of commodity fuels for the following reasons:

- water extracts water-soluble octane-raising substances (for example, alcohols) from gasoline, thereby reducing the anti-knock properties of commercial fuels;

- dissolved in the aqueous phase components boiling by-product exhibit increased corrosive activity in relation to the technological equipment of production and parts of the fuel system of the car [Irisov A.S. Alcohol as a motor fuel. - M.-L .: ONTI NKTP USSR, 1933.];

- at negative temperatures, the water frozen inside the fuel system leads to a complication or inability to start the car engine.

The task of the invention is the creation of a method of obtaining a component of gasoline based on low-boiling by-product of the production of butyl alcohols and light hydrocarbon fractions with an initial boiling point not lower than 25 ° C and a final boiling point not higher than 250 ° C (hereinafter the solvent), not causing turbidity, and deteriorating performance properties of commercial gasoline due to the presence in them of the dispersed aqueous phase.

To solve this problem, we propose a method for obtaining a component of automobile gasolines based on a low-boiling by-product of butyl alcohol production and a solvent that improves the detonation characteristics of gasolines and reduces the cost of commodity fuels by expanding the raw material base through the by-products of butyl alcohol production.

The proposed component of motor gasoline is obtained by dissolving the low-boiling by-product of the production of butyl alcohols in a solvent, followed by separating dispersed water using a gravity sedimentation separator or a centrifuge. Dissolving boiling by-product in the solvent is produced by mixing them with each other in a mass ratio of not more than 0.26: 0.74 (low-boiling by-product: solvent). Additionally, in the component of motor gasoline after the separation of dispersed water can be added anti-corrosion additive in an amount up to 0.05% of the mass.

The implementation of the proposed method consists in the sequential execution of the following operations:

1. Low-boiling by-product of the production of butyl alcohols, containing water up to 10% by weight, is mixed with the solvent in a mass ratio of not more than 0.26: 0.74 (light-boiling by-product: solvent). As a solvent, light hydrocarbon fractions are used with an initial boiling point not lower than 25 ° C and a final boiling point not higher than 250 ° C.

2. The emulsion obtained as a result of water separation is divided into separate phases (hydrocarbon and water) by settling in a gravity sedimentation separator or a centrifuge.

3. The resulting hydrocarbon phase, which is a component of motor gasoline, is diverted as a separate stream.

4. If necessary, an anticorrosive additive in the amount of up to 0.05% by weight can be added to the component of automobile gasolines, reducing the corrosive activity of substances that are part of the low-boiling by-product of the production of butyl alcohols.

The figure 1 shows the triangular Gibbs diagram with the results of the calculation of the phase equilibrium for the system solvent - low-boiling by-product (anhydrous) -water. The calculations were carried out on the basis of the NRTL phase equilibrium model at a temperature of 20 ° C. N-hexane was used as a solvent for the calculations.

Calculations of phase equilibrium showed that when the mass ratio of low-boiling by-product to solvent is no more than 0.26: 0.74, the moisture content in the obtained component of motor gasolines should not exceed the level of 205 ppm (calculated maximum concentration of dissolved water at 20 ° С).

The invention is illustrated by examples:

Example 1

To confirm the possibility of carrying out the invention and obtaining the stated result, laboratory tests were carried out to determine the residual water in the resulting component of motor gasoline. To do this, the initial low-boiling by-product containing 5% wt. water, mixed with various solvents in a mass ratio of 0.2: 0.8 (boiling by-product: solvent). The following hydrocarbon fractions were used as solvents:

- hexane fraction 26-80 ° C of the process of isomerization of light straight-run gasoline (laboratory samples No. 1, 2);

- straight-run gasoline fraction of 70-95 ° C (laboratory samples No. 3, 4).

- hydrotreated heavy fraction 130-220 ° C of catalytic cracking gasoline (laboratory samples No. 5, 6).

In the process of settling the mixtures obtained at a temperature of 20 ° C, two liquid layers were formed: hydrocarbon (upper) and water (lower). The process of settling each laboratory sample was conducted until the visual disappearance of the upper layer turbidity. Subsequently, a sample was taken from the clarified hydrocarbon layer, which was analyzed for residual moisture content by coulometric Karl Fischer titration. The results are presented in table 1.

According to Table 1, it can be seen that the moisture content in all laboratory samples is commensurate with the limiting concentration of water solubility obtained for a similar system by calculation (Fig. 1). This fact allows us to conclude that the water in the samples was predominantly in dissolved form, and the obtained samples can be used as components of motor gasoline when compounding commercial fuels.

Mixing in a mass ratio of 0.3: 0.7 (low boiling by-product: solvent) leads to an increase in the separation time into the hydrocarbon and aqueous phases (more than 48 hours), and the moisture content in the obtained laboratory samples exceeds the permissible level.

Example 2

Corrosion activity of the proposed component of automotive gasoline was determined on the basis of laboratory studies. The essence of the method used was a qualitative assessment of the corrosion of a steel rod immersed in a mixture of the test laboratory sample and distilled water. The research procedure involved keeping the polished steel rod in a mixture of 300 ml of the test sample and 30 ml of distilled water at 35 ± 1 ° C for 4 hours with constant stirring. The degree of corrosion of the rod was assessed by visual inspection of its surface with assignment of points on a scale from "0" to "3", where a score of "0" characterized the absence of visible traces of corrosion, and a score of "3" - the presence of signs of strong corrosion activity (spots and tarnishing on the surface rod occupied more than 5% of the area). The results of the research are presented in table 2.

Note: * - hexane fraction of the process of isomerization of light straight-run gasoline.

The obtained data allow us to conclude that the involvement of low-boiling by-product in the composition of motor fuels increases their corrosivity. However, the addition of an anti-corrosion additive to a component of automobile gasolines allows reducing corrosion in relation to the production process equipment and metal parts of the vehicle fuel system.

Studies have shown that the proposed method allows to obtain on the basis of low-boiling by-product of the production of butyl alcohols component of motor gasoline. The oxygenates that are part of the boiling by-product improve the detonation characteristics of the final products and help reduce their cost by reducing the amount of octane-raising additives involved and using the by-products of the production of butyl alcohols. An increase in the corrosivity of a component of automobile gasolines, associated with the involvement of a low-boiling by-product in its composition, can be prevented, if necessary, by adding an anti-corrosion additive.

Claims (2)

1. A method of producing a component of automobile gasolines, characterized in that after mixing the low-boiling by-product of the production of butyl alcohols and light hydrocarbon fractions with an initial boiling point not lower than 25 ° C and a final boiling point not higher than 250 ° C in a mass ratio of 0.2: 0.8 (low-boiling by-product: light hydrocarbon fraction); water is separated by a separation method and an anti-corrosion additive is added in an amount of 0.05% by weight. 2. Component automotive gasoline obtained by the method according to claim 1

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