Method for preparing low-aromatic transformer oil through medium-pressure hydrogenation of naphthenic base distillate oil

Abstract

The invention relates to a method for preparing low-aromatic transformer oil by medium-pressure hydrogenation of naphthenic base distillate oil, which comprises the following steps: 1) the naphthenic base distillate oil enters a first hydrogenation reactor and passes through a hydrofining reaction zone and a deep dearomatization reaction zone to realize hydrogenation removal of sulfur and nitrogen compounds and hydrogenation saturation of aromatic hydrocarbon in the oil product; 2) enabling the reactant flow to enter a second reactor, and respectively passing through a selective ring-opening reaction zone, an isomerization pour point depression reaction zone and a finishing reaction zone to realize selective ring opening of a polycyclic compound, isomerization of paraffin (branched chain) and saturation of cracked olefin; and 3) carrying out gas-liquid separation and rectification separation on the reaction product to obtain a low-aromatic transformer oil fraction and a clean light oil fraction. The method is suitable for upgrading and value-added processing of the transformer oil base oil from naphthenic crude oil and coal-based oil product fractions, has the characteristics of simple process flow, small device investment scale and high operation safety, and has the technical advantages of high transformer oil base oil yield, good product quality, environmental friendliness and the like.

Description

technical field

[0001] The invention belongs to the field of petrochemical industry, and in particular relates to a method for preparing low-aromatic transformer oil through medium-pressure hydrogenation of naphthenic distillate oil. Background technique

[0002] In recent years, with the development of the demand for the construction of the national power grid, projects such as the West-to-East Power Transmission, North-South Mutual Supply and National Networking have been rapidly promoted, and the quality requirements of transformer oil for power transmission and transformation equipment are getting higher and higher. Due to the comprehensive consideration of breakdown voltage, dielectric loss, viscosity, anti-gassing performance and low-temperature fluidity and other index factors, the State Grid stipulates that 110-550KV high-voltage transmission must use naphthenic transformer oil (C in carbon type composition) P value is less than 50%), but the naphthenic oil raw mater...

Examples

Embodiment 1

[0031] The normal second-line distillate produced by processing offshore naphthenic crude oil from a refinery's atmospheric and vacuum unit is used as the raw material. The properties of the raw material are shown in Table 2. After the raw material is mixed with hydrogen, it passes through the first hydrogenation reactor and the second hydrogenation reactor in sequence, and the volume space velocity of the feed is 1.0h -1 , the volume ratio of hydrogen to oil is 800:1, the hydrogen partial pressure of the system is 9.5MPa, wherein, the loading volume ratio of the pre-refining catalyst and the hydrodearomatization catalyst in the first reactor is 2:1, and the average reaction temperatures of the two catalysts are respectively 340°C and 350°C, the loading volume ratio of the selective ring-opening catalyst, isomerization decondensation catalyst and post-refining catalyst in the second reactor is 3:6:1, and the average reaction temperatures of the three catalysts are 350°C, 350°C,...

Embodiment 2

[0033] The first-line distillate oil obtained from the atmospheric and vacuum unit of a refinery processing offshore naphthenic crude oil is used as the raw material. The properties of the raw material are shown in Table 2. After the raw material is mixed with hydrogen, it passes through the first hydrogenation reactor and the second hydrogenation reactor in sequence, and the volume space velocity of the feed is 1.0h -1 , the volume ratio of hydrogen to oil is 800:1, the hydrogen partial pressure of the system is 9.5MPa, wherein, the loading volume ratio of the pre-refining catalyst and the hydrodearomatization catalyst in the first reactor is 1:1, and the average reaction temperatures of the two catalysts are respectively 350°C and 360°C, the loading volume ratio of selective ring-opening catalyst, isomerization decondensation catalyst and post-refining catalyst in the second reactor is 4:5:1, and the average reaction temperatures of the three catalysts are 350°C, 360°C and 3...

Embodiment 3

[0035] The raw material is the distillate of heavy diesel oil from coal liquefaction processed by the direct coal liquefaction unit of a certain enterprise. The properties of the raw material are shown in Table 2. After the raw material is mixed with hydrogen, it passes through the first hydrogenation reactor and the second hydrogenation reactor in sequence, and the volume space velocity of the feed is 0.5h -1 , the volume ratio of hydrogen to oil is 1200:1, the hydrogen partial pressure of the system is 9.5MPa, wherein, the loading volume ratio of the pre-refining catalyst and the hydrodearomatization catalyst in the first reactor is 1:2, and the average reaction temperatures of the two catalysts are respectively 360°C and 370°C, the loading volume ratio of the selective ring-opening catalyst, isomerization decondensation catalyst and post-refining catalyst in the second reactor is 5:4:1, and the average reaction temperatures of the three catalysts are 360°C, 365°C and 375°C,...

technical field

[0001] The invention belongs to the field of petrochemical industry, and in particular relates to a method for preparing low-aromatic transformer oil through medium-pressure hydrogenation of naphthenic distillate oil. Background technique

[0002] In recent years, with the development of the demand for the construction of the national power grid, projects such as the West-to-East Power Transmission, North-South Mutual Supply and National Networking have been rapidly promoted, and the quality requirements of transformer oil for power transmission and transformation equipment are getting higher and higher. Due to the comprehensive consideration of breakdown voltage, dielectric loss, viscosity, anti-gassing performance and low-temperature fluidity and other index factors, the State Grid stipulates that 110-550KV high-voltage transmission must use naphthenic transformer oil (C in carbon type composition) P value is less than 50%), but the naphthenic oil raw mater...

Examples

Embodiment 1

[0031] The normal second-line distillate produced by processing offshore naphthenic crude oil from a refinery's atmospheric and vacuum unit is used as the raw material. The properties of the raw material are shown in Table 2. After the raw material is mixed with hydrogen, it passes through the first hydrogenation reactor and the second hydrogenation reactor in sequence, and the volume space velocity of the feed is 1.0h -1 , the volume ratio of hydrogen to oil is 800:1, the hydrogen partial pressure of the system is 9.5MPa, wherein, the loading volume ratio of the pre-refining catalyst and the hydrodearomatization catalyst in the first reactor is 2:1, and the average reaction temperatures of the two catalysts are respectively 340°C and 350°C, the loading volume ratio of the selective ring-opening catalyst, isomerization decondensation catalyst and post-refining catalyst in the second reactor is 3:6:1, and the average reaction temperatures of the three catalysts are 350°C, 350°C,...

Embodiment 2

[0033] The first-line distillate oil obtained from the atmospheric and vacuum unit of a refinery processing offshore naphthenic crude oil is used as the raw material. The properties of the raw material are shown in Table 2. After the raw material is mixed with hydrogen, it passes through the first hydrogenation reactor and the second hydrogenation reactor in sequence, and the volume space velocity of the feed is 1.0h -1 , the volume ratio of hydrogen to oil is 800:1, the hydrogen partial pressure of the system is 9.5MPa, wherein, the loading volume ratio of the pre-refining catalyst and the hydrodearomatization catalyst in the first reactor is 1:1, and the average reaction temperatures of the two catalysts are respectively 350°C and 360°C, the loading volume ratio of selective ring-opening catalyst, isomerization decondensation catalyst and post-refining catalyst in the second reactor is 4:5:1, and the average reaction temperatures of the three catalysts are 350°C, 360°C and 3...

Embodiment 3

[0035] The raw material is the distillate of heavy diesel oil from coal liquefaction processed by the direct coal liquefaction unit of a certain enterprise. The properties of the raw material are shown in Table 2. After the raw material is mixed with hydrogen, it passes through the first hydrogenation reactor and the second hydrogenation reactor in sequence, and the volume space velocity of the feed is 0.5h -1 , the volume ratio of hydrogen to oil is 1200:1, the hydrogen partial pressure of the system is 9.5MPa, wherein, the loading volume ratio of the pre-refining catalyst and the hydrodearomatization catalyst in the first reactor is 1:2, and the average reaction temperatures of the two catalysts are respectively 360°C and 370°C, the loading volume ratio of the selective ring-opening catalyst, isomerization decondensation catalyst and post-refining catalyst in the second reactor is 5:4:1, and the average reaction temperatures of the three catalysts are 360°C, 365°C and 375°C,...

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