Different pressure distillation apparatus and process method

Abstract

The invention belongs to the field of petrochemical industry, and provides a different pressure distillation apparatus and a process method. The different pressure distillation apparatus main body comprises a pressure increase tower and a pressure reduction tower, wherein a tower bottom oil outlet of the pressure increase tower and a material inlet of the pressure reduction tower are connected through a communication pipeline, and the tower bottom oil outlet is higher than the material inlet. During a different pressure distillation process, raw material oil is heated to a set temperature through a heat exchange network and a heating furnace, and then enters the pressure increase tower, a light distillate oil product is extracted, the tower bottom oil enters the pressure reduction tower through the communication pipeline in a nature flow manner by adopting pressure difference and liquid level difference of the pressure increase tower and the pressure reduction tower, a heavy distillate oil product is extracted, and heavy oil or residue oil is extracted through bottom reduction. Compared to atmospheric and vacuum distillation, the crude oil different pressure distillation has the following characteristics that: the light component is sequentially subjected to vaporization and condensation under pressure increase and pressure reduction operation conditions so as to substantially reduce a crude oil heating temperature, reduce heating, reduce energy consumption, improve an extraction rate, and improve oil product quality; and compared to atmospheric and vacuum distillation, the heavy oil different pressure distillation has the following characteristics that: the light component in the heavy oil is extracted through the pressure increase tower so as to substantially reduce a vapor phase load of the pressure reduction tower, reduce energy consumption, and improve an extraction rate.

Description

technical field [0001] The invention belongs to the field of petrochemical industry, in particular to differential pressure distillation equipment and a process method. Background technique [0002] Crude oil distillation is the first process of petroleum processing. Distillate products such as gasoline, kerosene, diesel oil and wax oil are extracted through the process of atmospheric distillation and vacuum distillation by heating and reducing pressure. Usually, the crude oil enters the initial distillation tower through the heat exchange network to 240-260°C, and the naphtha is produced at the top of the tower, and the topped crude oil at the bottom of the tower passes through the heat exchange network to 290-310°C and enters the atmospheric furnace, and is heated to 350-350°C. Enter the atmospheric tower at 370°C to produce gasoline, kerosene, light diesel oil and heavy diesel oil fractions; the heavy oil at the bottom of the atmospheric tower is heated to 390-410°C by a ...

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Problems solved by technology

[0003] The disadvantages of the above-mentioned atmospheric and vacuum distillation process are: (1) In the atmospheric distillation process, the outlet temperature of the atmospheric furnace is restricted by both the cracking tendency of the oil product and the extraction rate of the atmospheric pressure. If the temperature is too high, the cracking of the oil product will be increased. Tendency, poor product quality, increased energy consumption, too low temperature, insufficient extraction rate at atmospheric pressure, excessive diesel components in the heavy oil at the bottom of the atmospheric pressure tower, usually the outlet temperature of the atmospheric pressure furnace is 350-370°C

(2) During the vacuum distillation process, the heavy oil at the bottom of the atmospheric tower contains a large number of lighter components that are not separated in time and enter the vacuum tower, increasing the vapor phase load of the vacuum tower, increasing the pressure drop of the whole tower, and improving the feed section. Residual pressure, increase energy consumption, reduce decompression extraction rate

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