Method for producing summer diesel fuel
The layered catalyst system in the hydrotreating process addresses the inefficiencies of existing diesel fuel production by enhancing gasoline yield and improving summer diesel fuel properties, leveraging a three-layer catalyst setup for efficient fraction utilization.
Patent Information
- Authority / Receiving Office
- RU · RU
- Patent Type
- Patents
- Current Assignee / Owner
- PUBLICHNOE AKTSIONERNOE OBSHCHESTVO SLAVNEFT YAROSLAVNEFTEORGSINTEZ PAO SLAVNEFT YANOS
- Filing Date
- 2025-05-16
- Publication Date
- 2026-07-01
AI Technical Summary
Existing methods for producing diesel fuel fail to efficiently utilize straight-run heavy fractions, leading to increased costs due to expensive dewaxing processes and insufficient production of gasoline and summer diesel fuel with improved low-temperature properties.
A method involving hydrotreating straight-run diesel fractions using a layered catalyst system comprising a protective catalyst, a hydrotreating catalyst, and a catalyst with additional isomerizing and splitting properties, applied at specific hydrogen pressures and temperatures, followed by mixing the treated fractions to achieve desired properties.
Enhances gasoline production by 0.8-7% and improves summer diesel fuel's low-temperature properties by 2-3 degrees, optimizing the use of previously underutilized heavy diesel fractions.
Smart Images
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Abstract
Description
[0001] The invention relates to processes in the oil refining industry, in particular to methods for producing diesel fuel.
[0002] A known method for producing diesel fuel involves distilling crude oil to separate gasoline, kerosene, and straight-run heavy and light diesel fractions, hydrotreating the straight-run heavy and light diesel fractions under a hydrogen pressure of 4.0-4.5 MPa, dewaxing, and adding additives. Following hydrotreating, heavy diesel fuel is rectified to separate winter diesel fuel and summer diesel fuel, and the distillate residue is sent for dewaxing (RU Patent No. 2675853).
[0003] However, this method does not allow obtaining a lot of cheap diesel fuel, since in the process of hydrotreating the straight-run heavy fraction of diesel fuel, many fractions remain that require an expensive dewaxing process.
[0004] The closest method for producing summer diesel fuel includes distillation of crude oil with the separation of gasoline, kerosene, straight-run fractions of heavy and light diesel fuel, hydrotreating of straight-run fractions of heavy and light diesel fuel, while hydrotreating of light straight-run fractions is carried out at a hydrogen-containing gas pressure of 4.0-4.5 MPa, straight-run fraction of heavy diesel fuel with a boiling point of 95% of the point up to 360 ° is carried out at a hydrogen-containing gas pressure of 6.0-8.5 MPa in a reactor with a nickel-molybdenum catalyst, which is loaded into it in two layers between which a space is provided for feeding hydrogen-containing gas to reduce the temperature of the gas-product mixture. The hydrogenate leaving the bottom of the reactor enters the stripping column to remove light hydrocarbons, gasoline and water from it. The resulting gasoline in an amount of up to 1.3% by weight. used as a component of commercial gasoline (RU patent No. 2759740).
[0005] However, this method does not allow obtaining a sufficient amount of gasoline and summer diesel fuel with improved low-temperature properties.
[0006] The purpose of the present invention is to increase the production of gasoline and summer diesel fuel with improved low-temperature properties on the same equipment.
[0007] The stated objective is achieved by using a method for producing summer diesel fuel, including distillation of oil with the separation of gasoline, kerosene, straight-run fractions of heavy and light diesel fuel, hydrotreating the straight-run fraction of light diesel fuel and the straight-run fraction of heavy diesel fuel in the presence of hydrotreating catalysts, wherein the straight-run fraction of heavy diesel fuel with a boiling point of 95% of the point from 361°C to 380°C is taken for hydrotreating, and the catalyst for hydrotreating the straight-run fraction of heavy diesel fuel additionally contains a layer of protective catalyst on top, and a layer of catalyst below, which has additional isomerizing and splitting properties in relation to the fraction of heavy diesel fuel.
[0008] Molybdenum-nickel hydrotreating catalysts of the following grades are used as hydrotreating catalysts: GO-117, GKD-202, NNS-66.
[0009] Molybdenum-nickel protective catalysts of brands such as НН-0304, НН-0305, НН-0306 are used as a protective catalyst.
[0010] Tungsten-nickel catalysts of the following brands are used as a catalyst layer, which has additional isomerizing and splitting properties in relation to the heavy diesel fuel fraction, for example, KGU-09, KGU-141, NNS-80.
[0011] The method is carried out as follows:
[0012] Fig. 1 shows the basic diagram of the production of summer diesel fuel.
[0013] The partially stripped oil mixture (1) prepared for distillation is fed to the main distillation column (2), where the kerosene fraction is collected into the stripping column (8), the straight-run light fraction of diesel fuel into the stripping column (9), and the straight-run heavy fraction of diesel fuel (6) into the stripping column (10). Gasoline (3) is collected from the top of the distillation column (2), and fuel oil (7) is withdrawn from the bottom of the distillation column (2).
[0014] A kerosene fraction (4) is withdrawn from the bottom of the stripping column (8). The straight-run fraction of light diesel fuel (5) from the stripping column (9) with a boiling point of 95% of the point up to 360°C is sent to the hydrotreating unit (11), where a hydrotreated fraction of light diesel fuel (12) is obtained at a hydrogen pressure of 4.0-4.5 MPa and a temperature of 395-400°C.From the stripping column (10), a straight-run fraction of heavy diesel fuel (6) with a boiling point of 95% of the point from 361°C to 380°C is taken for hydrotreating and sent to a hydrotreating unit (13), where the process is carried out at a hydrogen pressure of 6.0-8.5 MPa in a reactor into which the catalyst is loaded in three layers: an upper layer of a protective catalyst, a second layer of hydrotreating catalyst, then a free space is provided for feeding hydrogen-containing gas to reduce the temperature of the gas product mixture, which allows the chemical process to be carried out in an optimal temperature regime, then a third layer of catalyst is placed, which has additional isomerizing and splitting properties in relation to the fraction of heavy diesel fuel.
[0015] The hydrotreated product leaving the reactor bottom enters a stripping column to remove light hydrocarbons, gasoline, and water. The resulting gasoline (15), in quantities of up to 8.2% by weight, is used as a component of commercial gasoline.
[0016] The obtained fractions of hydrotreated light diesel fuel (12) and hydrotreated heavy diesel fuel (14) are mixed so that the cloud point of the mixture does not exceed minus 5°C and 95% of the volume does not boil above 360°C; if necessary, depressant, antiwear and cetane-enhancing additives (17) are added and summer diesel fuel (16) is obtained.
[0017] Examples of application of the proposed method are presented in Table 1.
[0018]
[0019] As can be seen from Table 1, the use of the proposed method for producing summer diesel fuel allows the use of an expanded straight-run fraction of heavy diesel fuel with a boiling point of 95% of the point from 361°C to 380°C for hydrotreating, part of which previously went into vacuum gas oil, to increase gasoline production by 0.8-7% and improve the low-temperature properties of summer diesel fuel by 2-3 degrees.
Claims
A method for producing summer diesel fuel, which includes distillation of petroleum with the separation of gasoline, kerosene, straight-run fractions of heavy and light diesel fuel, hydrotreating the straight-run fraction of light diesel fuel and the straight-run fraction of heavy diesel fuel in the presence of hydrotreating catalysts, characterized in that a straight-run fraction of heavy diesel fuel with a boiling point of 95% of the point from 361°C to 380°C is taken for hydrotreating, and the catalyst for hydrotreating the straight-run fraction of heavy diesel fuel additionally contains a layer of protective catalyst on top, and a layer of catalyst below, which has additional isomerizing and splitting properties in relation to the fraction of heavy diesel fuel, then the obtained fractions of hydrotreated light diesel fuel and hydrotreated heavy fuel are mixed so that the cloud point of the mixture does not exceed minus 5°C and 95% of the volume boils away no higher than 360°C.