RU2329294C1 - Method of obtaining motor petrol - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention pertains to the oil refining industry, and more specifically to the method of obtaining a component of motor petrol with low content of benzol. The proposed method involves splitting a catalysate of catalytic reforming into low-boiling and high-boiling fractions, hydrogenation of the low-boiling fraction with subsequent mixing of the hydrogenated fraction with the high-boiling fraction of catalysate. The method is differentiated by that, from the low-boiling fraction of the catalysate, through extra distillation, a fraction is separated, with boiling point in the 30-90°C interval, which is hydrogenated in a reactor, consisting of 2-5 contact zones for the raw material and catalyst. To the fraction obtained through mixing the separated hydrogenated fraction with the high-boiling fraction of the catalysate, an extra benzene fraction from different processes is added, with obtaining of commercial grade motor petrol.

EFFECT: proposed method allows improving technological effectiveness of the process due to release a hydrogenated fraction from ballast fractions of light hydrocarbons, obtaining a component of motor petrol, containing not more than 0,5% mass of benzol with minimal lowering of the octane number (not more than 0.5 IM units), obtaining high octane commercial grade petrol with benzol content of not more than 1% of the mass.

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Description

The invention relates to the refining industry, and specifically to a method for producing automobile gasoline with a reduced content of benzene.

A known method of producing automotive gasoline with a reduced content of benzene by alkylating benzene contained in light gasoline fractions with light olefins, for example propylene.

Alkylation of benzene with propylene leads to the formation of predominantly isopropylbenzene, which helps to reduce the concentration of benzene and increase the octane number of gasoline. Due to the addition of propylene to benzene molecules, the volume of gasoline fractions increases by an average of 20-30%. The degree of conversion of benzene is 92% (Kaminsky E.F., Khavkin V.A. et al. Promising technologies for the production of gasolines with improved environmental characteristics, TsNIITEneftekhim, M., 1995, p. 46).

The disadvantage of this method is the high content in the resulting product of aromatic hydrocarbons With ₉ and higher, which have, like benzene, significant toxicity (although to a lesser extent than benzene).

Given the current requirements for gasoline, limiting the total content of aromatic hydrocarbons, this method cannot be considered sufficiently effective.

Closest to the claimed is a method for producing motor gasoline with a low benzene content, comprising separating the catalytic reforming catalysis into low boiling (N.K. - 90 ° C) and high boiling (90 ° C - K.K.) fractions, selective hydrogenation of the low boiling fraction, mixing the hydrogenated fraction with a high boiling point of catalysis to obtain the target product.

The process of hydrogenation of the low-boiling fraction is carried out at a pressure of 3 MPa, temperature> 200 ° C, a volumetric feed rate of 1.5 h ^-1 , a hydrogen / feed ratio of 1000 nl / l in the presence of a catalyst based on noble metals (Kaminsky E.F., Khavkin V.A. et al. Russian Chemical Journal (Journal of the Russian Chemical Society named after D.I. Mendeleev), 1997, vol. XLI, p. 58).

The disadvantage of this method is the significant loading of the catalytic system with recycle "ballast" fractions (fr. N.K. - 90 ° C reforming, directed to selective hydrogenation, contains 23 wt.% Benzene, the rest is paraffinic and naphthenic hydrocarbons that do not need to be refined, including light hydrocarbons), which leads to an unjustified increase in the reaction volume of the system, increased metal consumption of the equipment and the deterioration of the technical and economic indicators of the process.

The objective of the invention is to develop a method for producing automotive gasoline with a low benzene content, which allows to improve the processability while maintaining high anti-knock characteristics of the fuel.

To solve this problem, a method for producing automobile gasoline is proposed, which includes the separation of catalytic reforming catalysis into low boiling and high boiling fractions, hydrogenation of the low boiling fraction, followed by mixing of the hydrogenated fraction with a high boiling catalysis fraction. The method is characterized in that a fraction boiling out within the temperature range of 30-90 ° C is isolated from the boiling fraction by further rectification, which is subjected to hydrogenation in a reaction apparatus consisting of 2-5 contact zones of the feedstock and the catalyst.

To obtain commercial motor gasoline, gasoline fractions of various processes are added to the fraction obtained by mixing the separated hydrogenated catalysate fraction with a high boiling catalysis fraction: the isomerization process and / or the light gasoline fraction of direct distillation of oil, etc. Methyltretbutyl ether can also be added to obtain high octane gasoline.

The hydrogenation process is carried out at a temperature of 200-330 ° C, a pressure of 2-5 MPa, a volumetric feed rate of 0.5-3.0 hour ^-1 in the presence of a catalyst based on noble metals.

A feature of the method is that the fraction subjected to boiling inside the temperature range of 30-90 ° C is subjected to hydrogenation, which avoids loading the catalyst system with recirculating "ballast" fractions of light hydrocarbons. The resulting hydrogenated fraction is then mixed with a high boiling point catalysate fraction (90 ° C - K.K.) followed by the addition of various processes gasoline fractions: automotive gasoline isomerization fraction, light gasoline direct distillation fraction, etc. It is also possible to add methyl tert-butyl ether.

In the proposed method, the hydrogenation process is carried out in a reaction apparatus, consisting of 2-5 zones of contact of the feedstock and the catalyst, which makes it possible to uniformly bring cold hydrogen to the reacting mixture to maintain a given process temperature.

The proposed method allows to improve the processability by freeing the hydrogenated fraction from the "ballast" fractions of light hydrocarbons, to obtain a component of motor gasoline containing not more than 0.5 wt.% Benzene with a minimum reduction in octane number (not more than 0.5 units I. M.), and when mixing the hydrogenated fraction with a high boiling point of catalysis, as well as the gasoline fractions of various processes (gasoline fraction of the isomerization process, methyl tert-butyl ether, light gasoline fraction, direct per oil transportation, etc.), to obtain high-octane commercial automobile gasoline with a benzene content of not more than 1 wt.%.

The following are specific examples of the proposed method.

Example 1

The catalytic reforming catalyst is divided into low boiling - N.K. - 90 ° С, yield - 26 wt.%, Octane number - 73 (I.M.) and high boiling point - 90 ° С - K.K., yield - 74 wt.%, Octane number - 98 (I.M. ) fractions. From boiling fraction containing 18 wt.% Benzene, by additional distillation allocate: fraction N.K. - 30 ° С - yield - 25 wt.%, Benzene content - traces, and the fraction boiling in the temperature range 30-90 ° С - yield - 75 wt.%, Benzene content - 25 wt.%, Octane number - 80 (THEM.).

The fraction boiling in the temperature range 30-90 ° C is subjected to hydrogenation at a temperature of 200 ° C, a pressure of 5 MPa, a bulk feed rate of 0.5 h ^-1 in the presence of an alumina-platinum catalyst in two consecutive contact zones of the raw material and catalyst.

The result is a hydrogenated fraction with a benzene content of less than 0.4 wt.% And characterized by an octane number of 79.5 (I.M.) with a yield of 99 wt.% To the starting fraction.

The resulting hydrogenated fraction is mixed with a high boiling fraction of the reforming catalyst.

To obtain commercial gasoline, a gasoline fraction of the isomerization process (FR ₅ -C ₆ ) and a light gasoline fraction of direct distillation of oil are additionally added to the mixed fraction.

The result is commercial gasoline AI-93 containing less than 1 wt.% Benzene.

Example 2

The catalytic reforming catalyst is divided into low boiling - N.K. - 90 ° С, yield - 23 wt.%, Octane number - 72 (I.M.) and high boiling point - 90 ° С - K.K., yield - 77 wt.%, Octane number - 97 (I.M. ) fractions. From boiling fraction containing 25 wt.% Benzene, by additional distillation allocate: fraction N.K. - 60 ° С - yield - 50 wt.%, Benzene content - traces, and the fraction boiling in the temperature range 60-90 ° С, yield - 50 wt.%, Benzene content - 45 wt.%, Octane number - 81 ( THEM.).

The fraction boiling in the temperature range 60-90 ° C is subjected to hydrogenation at a temperature of 260 ° C, a pressure of 3.5 MPa, a feed space velocity of 1.5 h ^-1 in the presence of an aluminum-palladium catalyst in three consecutive contact zones of the raw material and catalyst.

The result is a hydrogenated fraction with a benzene content of 0.3 wt.% And characterized by an octane rating of 80.5 (I.M.) with a yield of 98.5 wt.% On the starting fraction.

The resulting hydrogenated fraction is mixed with a high boiling fraction of the reforming catalyst.

To obtain commercial motor gasoline, the gasoline fraction of the isomerization process (FR ₅ -C ₆ ) and methyl tert-butyl ether (MTBE) are additionally added to the obtained mixed fraction.

The result is commercial gasoline AI-95 containing less than 1 wt.% Benzene.

Example 3

The catalytic reforming catalyst is divided into low boiling - N.K. - 90 ° С, yield - 27 wt.%, Octane number - 74 (I.M.) and high boiling point - 90 ° С - K.K., yield - 73 wt.%, Octane number - 99 (I.M. ) fractions. From boiling fraction containing 26.5 wt.% Benzene, by additional distillation emit: fraction N.K. - 40 ° С - yield - 35 wt.%, Benzene content - traces, and the fraction boiling in the temperature range 40-90 ° С, yield - 65 wt.%, Benzene content - 35 wt.%, Octane number - 83 ( THEM.).

The fraction boiling in the temperature range 40-90 ° C is subjected to hydrogenation at a temperature of 330 ° C, a pressure of 2 MPa, a bulk feed rate of 3 h ^-1 in the presence of an alumina-platinum catalyst in five consecutive contact zones of the raw material and catalyst.

The result is a hydrogenated fraction with a benzene content of 0.5 wt.% And characterized by an octane number of 82 (I.M.) with a yield of 98 wt.% Of the starting fraction.

The resulting hydrogenated fraction is mixed with a high boiling fraction of the reforming catalyst.

To obtain commercial motor gasoline, the gasoline fraction of the isomerization process (FR ₅ -C ₆ ) and methyl tert-butyl ether (MTBE) are additionally added to the obtained mixed fraction.

The result is commercial gasoline AI-95 containing less than 1 wt.% Benzene.

Claims (4)

1. A method of producing automobile gasoline, comprising separating the catalytic reforming catalysis into a low boiling and high boiling fraction, hydrogenating the low boiling fraction, followed by mixing the hydrogenated fraction with a high boiling catalysis fraction, characterized in that a fraction boiling off within the temperature range 30 is isolated from the low boiling fraction of catalysis -90 ° C, which is subjected to hydrogenation in a reaction apparatus, consisting of 2-5 zones of contact of raw materials and catalyst, and to the fraction Obtained by mixing the selected fraction with a hydrogenated high boiling fraction catalyzate further added petroleum fractions of various processes, to produce motor gasoline. 2. The method according to claim 1, characterized in that to the fraction obtained by mixing the selected hydrogenated fraction with a high boiling point of catalysis, methyl tert-butyl ether is additionally added. 3. The method according to claim 1, characterized in that the gasoline fraction of the isomerization process and / or the light gasoline fraction of direct distillation of oil are used as gasoline fractions of various processes. 4. The method according to claim 1, characterized in that the hydrogenation is carried out at a temperature of 200-330 ° C, a pressure of 2-5 MPa, a volumetric feed rate of 0.5-3.0 h ^-1 in the presence of a catalyst based on noble metals.