CS260313B1 - The way gasoline is produced - Google Patents

Abstract

Lower lead or unleaded motor gasoline is produced by a combination of distillation and catalytic reforming processes. The feedstock for catalytic reforming includes fractions with a distillation range of 60°C to 150°C and a fractional range of 90°C to 200°C, prepared by distillation of gasoline distillate with a boiling point of up to 200°C. The resulting reforming product has a favorable fractional composition and a high octane number.

Description

The invention relates to a method for producing motor gasoline with a lower lead content or without lead by combining distillation and catalytic reforming processes.

The current trend in reducing the content of leaded antiknock agents in fuels for spark-ignition engines, especially in automotive gasolines, and the gradual introduction of unleaded gasolines requires the use of high-octane components in their production, which compensate for the decrease in the octane level of gasolines. For this reason, it is necessary to further reduce the content of crude oil-based first-distillate gasolines in motor gasolines and replace them with high-octane components. Preferred components for low-lead and unleaded gasolines are isomerizate of the pentane-hexane fraction, olefinic gasolines from catalytic cracking, alkylate, oligomeric and polymer gasolines. The production of such components is very expensive, especially from an investment point of view. Another option is the use of oxygenated compounds, mainly with 4 to 7 carbon atoms in the molecule, such as ethers (MTBE, ETBE, TAME, DIPE) and alcohols (sec-butanol, isobutanol, tert-butanol), which, unlike methanol, do not separate from gasoline due to water and low temperatures. However, their increased use is limited by the relatively high price, the available amount of raw materials for their production, and international regulations and standards for the oxygen content in gasoline.

In refineries of predominantly hydroskimming type, the only process that allows the production of high-octane components for gasolines containing 0.1 to 0.25 g Pb. ^dm3 or unleaded gasolines is catalytic reforming.

In such refineries, especially at lower crude oil processing levels, there is usually free capacity in the reforming units to process other raw materials than naphtha.

The invention provides a method for producing motor gasolines containing alkyl lead antiknock agents tetramethyl lead and/or tetraethyl lead in a concentration of 0.1 to 0.25 g Pb/ /dm“ ³ or without lead by a combination of distillation and catalytic reforming processes on catalysts containing platinum or platinum and rhenium. In the production of motor gasolines according to the invention, gasoline with a fractional range of up to 200 °C is divided into fractions A, B and C. Fraction A has a distillation range of up to 85 °C, fraction B from 60 °C to 150 ^° C and fraction C from 90 °C to 200 °C. In the production of motor gasolines with a higher OCVM, it is advantageous to prepare fractions Ai with a boiling point of up to 75 °C and A2 with a fractional range of 45 °C to 85 °C instead of fraction A and to add fraction Ai to motor gasoline. Fraction A2 is then used for other purposes.

In the production of fuel for spark ignition engines according to the invention, fraction B is catalytically reformed to reformate BR with an octane number determined by a research method from 80 to 95. Preferred distillation ranges of the fraction

B is from 75 °C to 110 °C, when this fraction contains 38 — 46 mass % of cyclic hydrocarbons. The obtained BR reformate has a favorable distillation range from 30 °C to 135 °C to 150 °C, relatively good sensitivity to alkyl lead antiknock agents and a favorable difference between the octane number by the research and motor methods, which is usually referred to as the sensitivity of gasoline. The preparation of BR reformate significantly increases the octane level of the light components of motor gasoline not only by the formation of aromatics Cs and C7, but also as a result of partial cleavage, in particular, of the slightly branched low-octane alkane hydrocarbons C6 to Ce to isoalkanoic hydrocarbons Cs and Ce. This fact therefore has a very positive effect on both the course of the distillation curve and the distribution of the octane number along the distillation curve, especially in the range up to 100 °C, in which the motor gasolines produced so far from light primary gasoline and heavy gasoline reformate had a very low octane number. In addition to the reported formation of aromatics C6 and C7, as well as isoalkanes Cs and C6, the reforming of fraction B also changes the structure of other hydrocarbons, which further determines that when blending motor gasolines according to the invention, especially using fractions A, or Ai and fractions P, Q and X from the redistillation of reformate CR, a non-additive increase in the octane number by 0.7 to 2.2 octane number units is observed.

Fraction C with a preferred distillation range of 105 °C to 190 °C is reformed according to the invention to reformate CR with an octane number by the research method of 89 to 98. Part of the reformate CR is separated by distillation into fractions P, Ri, Q, R2 and X, with fraction P having a boiling point of up to 75 °C, fraction Ri having a distillation range of 60 °C to 100 °C, fraction Q having a distillation range of 90 °C to 125 °C, fraction R2 having a distillation range of 110 °C to 170 °C and fraction X having an initial boiling point of 145 °C to 165 °C. Fractions Ri and R2 are usually used for purposes other than the production of motor gasoline, but in the case of their balance surplus they are preferred components of motor gasolines according to the invention. When the CR product is distilled, LO-12 wt.% is usually obtained. fraction P, 45 to 55 wt. % fractions Rt and R2, 10 to 15 wt. % fraction Q and 20 to 35 wt. % fraction X.

Separate reforming of fraction B and fraction C to form reformates BR and CR is very advantageous for several reasons. First, these are the reforming conditions, with the reforming of fraction B taking place in a more severe regime, especially in terms of temperature, and second, these are the liquid reformate yields and the hydrogen content in the circulating gas. In the case of reforming a mixture of fractions B and C under reforming conditions optimal for fraction B, there would be significant splitting and thus a low yield of liquid reformate, large gas formation and increased energy consumption of the process. In the case of reforming under optimal conditions for fraction C, there would be low conversion of hydrocarbons of fraction B and thus the lower boiling portions of the reformate thus obtained would have a low octane number.

The motor gasolines according to the invention are prepared by mixing fractions A or Ai and fractions BR, CR, P, Q and X. In the case of production of fuel containing lead anti-knock agents, these are added in an amount of from 0.1 to 0.25 g Pb/l in the form of tetraethyl lead and/or tetramethyl lead, while when using a mixture of alkyl lead additives, the content of tetraethyl lead is preferably 50 to 80% by weight in the mixture of anti-knock additives.

As further components of the motor gasolines according to the invention, oleaginous fractions from pyrogen with a boiling point of 235 °C in an amount of 2.5 to 35% by weight and/or fraction from the raffinate after extraction of aromatics with a boiling point of up to 115 °C in an amount of 1.5 to 25% by weight and/or dialkyl ethers with 5 to 7 carbon atoms in the molecule in an amount of 3.5 to 15% by weight are used.

The method of producing motor gasoline according to the invention is documented in the examples given, but without the subject matter of the invention being limited thereby in any way.

Example 1

Gasoline with a distillation range of up to 197 degrees Celsius was distilled into 3 fractions such that fraction A had a boiling point of 70°C, fraction B ₍ had a fractional range from 65°C to 140°C, and fraction C had an initial boiling point of 90°C.

Fraction B was reformed after hydrodesulfurization on a Pt catalyst at a temperature of 510 °C and a pressure of 2.8 MPa. The ratio of the circulating hydrogen-containing gas was 2,000 m ³ / /Ira ³ of raw material. The properties of the BR reformate prepared in this way are given in Table 1.

Fraction C was hydrodesulfurized to a sulfur content below 0.5 ppm and subsequently reformed on a Pt catalyst at 505 °C to CR reformate. Part of the liquid CR reformate (52 wt. % of CR reformate) was fractionated into 5 fractions, the yields of which were 10.7 wt. % for fraction P, 50.2 wt. % for a mixture of fractions R1 and R2, 13.2 wt. % for fraction Q and 25.9 wt. % for fraction X. The properties of these fractions are given in Table 1. The remaining part of the CR reformate was used without change for the preparation of motor gasolines according to the invention.

Example 2

Gasoline with a distillation range of up to 185 degrees Celsius was separated by distillation into fractions Ai, A2, B _{and Cn} so that fraction Ai had a boiling point of up to 60 °C, fraction A2 had a distillation range of 55 ^° C to 85 °C, fraction Bn from 75 ^° C to 110 ^° C and fraction Cn had an initial boiling point of 90 °C. Fraction Bn was reformed on a Pt catalyst in the presence of hydrogen-containing gas at a temperature of 510 °C and by transferring 2 kg of raw material to 1 kg of catalyst. The properties of the obtained reformate BRn are given in Table 2. Fraction C was processed similarly to Example 1.

Example 1 3

Using the fractions and products listed in Examples 1 and 2, motor gasolines according to the invention were prepared. Table 3 shows the mixing ratios and properties of two high-octane motor gasolines with a very low lead content and two high-octane benzoyl gasolines. In the preparation of gasoline 3, a pyrogen fraction with a boiling point of up to 218 °C was used as an additional component, and in gasoline 4, methyl tert.butyl ether (MTBE) was used. It is obvious that the method of producing motor gasolines according to the invention allows the preparation of such high-octane gasolines, which in all indicators reach world-class parameters. The data in the table also show that in the production of motor gasolines according to the invention, a non-additive increase in octane number occurs, which is a consequence of the advantages of the process according to the invention.

~...........- ' a b u I k a 1

Properties of gasoline components according to the invention

Component BR, CR P R1 + R2 Q X Density, kg. m ^-3 742 775 650 780 760 865 Distillation curve start of distillation °C 35 57 30 66 92 156 10% vol. °C 52 85 32 86 98 162 50% vol. °C 83 130 42 112 105 168 90% vol. °C 125 161 59 139 113 190 end of distillation °C 155 202 73 153 124 218 OCVM 91.5 92 83 87 79 102 OCMM 86.3 83 83 78 75 89

Table 2

Properties of components according to example 2

Component Al A2 BRn Density, kg. m~ ³ 623 678 731 Distillation curve start of dest. °C 28 55 37 10% vol. °C 32 67 63 50% vol. °C 37 73 98 90 o/o vol- °C 51 78 119 end dest. °C 60 85 143 OCVM 75 58 90, OCMM 74 56 84,

Table 3

Example of composition and properties of motor gasolines according to the invention

Motor gasoline 1

Composition (% by weight)

Faction A 5

Ai faction —

Fraction P 15

BRi 45 reform

BR _n reformat —

CR 15 reform

Faction Q —

Fraction X 20

MTBE Fraction from pyrogasoline Properties of motor gasolines

Density, kg. m~ ^3,747

Distillation curve °/o vol. °C 50% vol. °C 95% vol. °C 172 end of dest. °C 210

Pb content g. dm ^-3 0.15

OCM (calculated) 94.4

OČVM (reality) 96

OČMM (reality) 90.6

2 3 4 3 4 20 7 8 — 40 35 40 — — 20 30 25 3 9 V» 5 19 13 10 — — 10 13 743 773 747 53 56 51 97 105 96 172 170 171 211 214 210 0.15 0 0 94.6 92.8 94.2 96 95 95 89.8 87.3 88.1

Claims (7)

1. A process for the production of motor gasoline with or without alkylated alkylated anti-knock agents with a concentration of up to 0,25 g Pb / dm ³ by a combination of distillation and catalytic refraction processes on platinum or platinum and rhenium containing catalysts, characterized in that a fraction range of up to 200 ° C is separated into fractions A, B and C, fraction A having a boiling point of up to 85 ° C, fraction B having a distillation range of 60 ° C to 150 ° C and fraction C of 90 ^° C to C 200 ° C fraction B is catalytically reformed in the presence of hydrogen or hydrogen-containing gas to BR reformate with an OCM of 80 to 95 and fraction C is catalytically reformed in the presence of hydrogen or hydrogen-containing gas to CR reformat with an OCM of 89 to 98, distillate into fractions P, R1, Q, R2 and X, where fraction P has a boiling point up to 75 ° C, fraction R1 has a distillation range of 60 ° C to 100 ° C, fraction Q has de a fractionation range from 90 ° C to 125 ° C, fraction R2 has a fractionation range from 110 ° C to 170 ° C, and fraction X has a boiling point from 145 ° C to 165 ° C, and motor gasoline is formed from fractions A, % Of P, Q, X and BR reformate, containing from 5 to 60 wt. from 8 to 35 wt. fraction A, from 5 to 40% w / w; fraction P, from 3 to 28 wt. fraction Q and from 2 to 38 wt. fraction X. 2. The production method according to claim 1, wherein fraction B is reformed at I invoke a temperature of 470 ° C to 530 ° C with a flow rate of 0.8 to 2.5 h ^-1 and at a pressure of 1.5 to 3.5 MPa. 3. A process according to claim 1, characterized in that fraction C is reformed at ^460: 'C to 520 ° C with a space velocity of 1.5, ¹ and the 3 hours under a pressure of 1.0 to 3.5 MPa. Process according to Claims 1 and 2, characterized in that fraction B has a preferred distillation range of 75 ^° C to 115 ° C. 5. A process according to claim 1, characterized in that fraction A is replaced by fraction Ai, which is prepared by distilling the gasoline distillate into fractions Αι, A2, B and C, fraction Ai having a boiling point of 75 ° C. , fraction A2 has a distillation range from 45 ° C to 85 ° C and fractions B and C have a distillation range as in point 1. 6. A process according to any one of claims 1 to 5, wherein the further component of motor gasoline is CR reformate in an amount of from 5 ' 7. A process according to claim 1, wherein the other components of motor gasoline are fractions R1 in an amount of 0.5 to 12% by weight, R2 in an amount of 2 to 22% by weight. and / or olefinic fractions of pyrobenzine having a boiling point of up to 235 ° C in an amount of from 2.5 to 35% by weight. and / or a raffinate fraction after the extraction of aromatics having a boiling point of up to 115 ° C in an amount of from 1.5 to 25% by weight. and / or C 5 -C 7 dialkyl ethers in an amount of from 2.5 to 15 wt%.