Method of oil refining
By hydrotreating heavy diesel fractions at elevated pressures and optimized conditions, the method enhances diesel fuel yields and reduces operational costs, addressing inefficiencies in existing oil refining processes.
Patent Information
- Authority / Receiving Office
- RU · RU
- Patent Type
- Patents
- Current Assignee / Owner
- PUBLICHNOE AKTSIONERNOE OBSHCHESTVO SLAVNEFT YAROSLAVNEFTEORGSINTEZ PAO SLAVNEFT YANOS
- Filing Date
- 2026-02-05
- Publication Date
- 2026-07-02
AI Technical Summary
Existing methods in oil refining face inefficiencies such as increased energy costs, catalyst wear, and reduced yield of marketable diesel fuels due to the presence of ballast fractions that do not require dewaxing, leading to unnecessary cracking and hydrogen consumption, and the production of summer fuel is not cost-effective.
Hydrotreating straight-run heavy diesel fractions at elevated pressures and hydrogen content, along with optimized space velocity, to separate and process fractions suitable for winter and summer diesel fuels, while utilizing excess hydrotreated light diesel fuel for winter fuel production.
Increases the yield of gasoline, light diesel, and heavy diesel fuels by 3.3-5.8%, 1.2-2.1%, and 1.5-5.0% respectively, while reducing energy costs and catalyst wear, and optimizing the production of winter and summer diesel fuels.
Smart Images
Figure 00000003_ABST
Abstract
Description
[0001] The invention relates to processes in the oil refining industry, in particular to methods for producing motor fuels.
[0002] A known method for producing diesel fuel involves crude oil distillation to separate kerosene, light and heavy diesel fuel, catalytic hydrotreating and dewaxing of the diesel fuel, compounding, and the introduction of additives. During crude oil distillation, straight-run light diesel fuel and heavy diesel fuel fractions with specific quality parameters are isolated and then processed. Thus, the straight-run light diesel fuel fraction is isolated with a cloud point ranging from 5°C above to 5°C below the standard value for the resulting commercial winter diesel fuel, and is then subjected to hydrotreating. The isolated straight-run heavy diesel fuel fraction is fully hydrotreated and subsequently catalytically dewaxed.Commercial winter diesel fuel of a given class is obtained by compounding a hydrotreated fraction of light diesel fuel and a balance amount of a fraction of heavy diesel fuel that has undergone hydrotreating and catalytic dewaxing (RU patent no. 2535492).
[0003] However, as a result, the feedstock of catalytic dewaxing units contains a significant amount (30 to 60%) of fractions that do not require dewaxing and are suitable for producing both winter and summer diesel fuel components. The presence of these ballast fractions in the feedstock, given the limited throughput of catalytic dewaxing units, reduces the contact time of heavy fractions, leads to increased energy costs for heating the feedstock and subsequent product separation, reduces the overall yield of marketable diesel fuels due to unnecessary cracking of ballast fractions, requires very strict process conditions in the dewaxing reactor and increased consumption of scarce hydrogen, which in turn leads to frequent catalyst regeneration and significant operating costs, leading to accelerated catalyst wear.
[0004] A known method of oil refining includes distillation of crude oil to separate kerosene, straight-run heavy and light diesel fractions, hydrotreating of the straight-run heavy and light diesel fractions under a hydrogen pressure of 4.0-4.5 MPa, dewaxing, and the introduction of additives. In this process, heavy diesel fuel after hydrotreating is subjected to rectification to separate winter diesel fuel and summer diesel fuel, and the distillate residue is sent for dewaxing (RU Patent No. 2675853).
[0005] However, this method does not allow obtaining a lot of cheap summer fuel, since in the process of hydrotreating the straight-run heavy fraction of diesel fuel, many fractions remain that require an expensive dewaxing process.
[0006] The closest method is oil refining, which includes distillation of 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, introducing additives, while hydrotreating of straight-run fraction of heavy diesel fuel is carried out at a pressure of 6.0-8.5 MPa of hydrogen-containing gas with a hydrogen content of 60-70% by volume.
[0007] The method is carried out as follows:
[0008] Fig. 1 shows the basic diagram of the production of fractions of gasoline, light and heavy diesel fuels.
[0009] 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). Fuel oil (7) is withdrawn from the bottom of the distillation column (2).
[0010] 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) is sent to a hydrotreating unit (11), where, at a hydrogen-containing gas pressure of 4.0-4.5 MPa with a hydrogen content of 60-70 vol.% and a temperature of 370-400 °C, a hydrotreated fraction of light diesel fuel (12) is obtained. The fraction of heavy diesel fuel (6) from the stripping column (10) with a boiling point of 95% up to 370 °C is sent to a hydrotreating unit (13), where the process is carried out at a hydrogen-containing gas pressure of 6.0-8.5 MPa with a hydrogen content of 60-70 vol.% at a temperature of 300-399 °C and a space velocity of 1.08-1.2 h -1to obtain a hydrotreated fraction of heavy diesel fuel (14) and gasoline (17). The resulting fractions of hydrotreated light diesel fuel (12) and hydrotreated heavy diesel fuel (14) are mixed so that the mixture's cloud point does not exceed minus 5°C and 95% of the volume does not boil above 360°C. Additives (15) are introduced, and commercial summer diesel fuel (16) is obtained (RU patent no. 2759740).
[0011] However, in this method, the production of gasoline is insignificant and it is not possible to obtain more fractions of light and heavy diesel fuels due to the low boiling point of 95% of the straight-run fraction of heavy diesel fuel.
[0012] The aim of the present invention is to increase the yield of gasoline, light and heavy diesel fuel fractions.
[0013] The stated objective is achieved by using a method of oil refining, 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 at an elevated pressure of hydrogen-containing gas, hydrotreating the straight-run fraction of heavy diesel fuel at an elevated pressure of hydrogen-containing gas, while the straight-run fraction of heavy diesel fuel with a boiling point of 95% of the point from 371 ° C to 380 ° C is taken for hydrotreating, and hydrotreating the straight-run fraction of heavy diesel fuel is carried out at a pressure of hydrogen-containing gas of 7.5-8.5 MPa with a hydrogen content in the gas of 95.5-99.9 vol.% and a space velocity of 0.70-1.05 h -1 .
[0014] The method is carried out as follows:
[0015] Fig. 2 shows the basic diagram of the production of fractions of gasoline, light and heavy diesel fuels.
[0016] 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) with a boiling point of 95% of the point from 371°C to 380°C 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).
[0017] 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) is sent to the hydrotreating unit (11), where, at a hydrogen-containing gas pressure of 4.0-4.5 MPa with a hydrogen content of 60-70 vol.% and a temperature of 370-400 °C, a hydrotreated fraction of light diesel fuel (12) with a cloud point of no higher than minus 22 °C is obtained. The straight-run fraction of heavy diesel fuel (6) with a boiling point of 95% of the point from 371 °C to 380 °C from the stripping column (10) is sent to the hydrotreating unit (13). In the hydrotreating unit (13), the process is carried out at a hydrogen-containing gas pressure of 7.5-8.5 MPa with a hydrogen content of 95.5-99.9 vol. %, at a temperature of 300-399°C and a space velocity of 0.70-1.05 h -1to obtain gasoline (17) and a hydrotreated fraction of heavy diesel fuel (14) with a cloud point of no more than plus 2°C. Part of the obtained fraction of hydrotreated light diesel fuel (12) and the hydrotreated heavy fraction of 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, additives (15) are introduced and commercial summer diesel fuel (16) is obtained. The excess portion of the hydrotreated fraction of light diesel fuel (12) is used to obtain commercial winter fuel (18).
[0018] Examples of the proposed invention are presented in Table 1.
[0019]
[0020]
[0021] The data presented in Table 1 show that an increase in the 95% boiling point from 371°C to 380°C of the straight-run fraction of heavy diesel fuel and a decrease in the cloud point of the heavy diesel fraction during hydrotreating under the proposed conditions leads to an increase in the yield of the straight-run fraction of heavy diesel fuel by 1.5-5.0% by weight of processed oil and an increase in the amount of hydrotreated light diesel fuel fraction for obtaining commercial winter diesel fuel by 7.6-16.8% by weight. The yield of commercial summer diesel fuel increases by 1.2-2.1% by weight and the yield of gasoline by 3.3-5.8% by weight.
Claims
A method for refining oil, 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 at an elevated pressure of hydrogen-containing gas, hydrotreating the straight-run fraction of heavy diesel fuel at an elevated pressure of hydrogen-containing gas, characterized in that the straight-run fraction of heavy diesel fuel with a boiling point of 95% of the point from 371 to 380 °C is taken for hydrotreating, and hydrotreating the straight-run fraction of heavy diesel fuel is carried out at a pressure of hydrogen-containing gas of 7.5-8.5 MPa with a hydrogen content in the gas of 95.5-99.9 vol. % and a space velocity of 0.70-1.05 h -1 .