RU2138536C1 - Method for production of petroleum fractions - Google Patents

Abstract

FIELD: petroleum processing. SUBSTANCE: fractions are produced by feeding preheated hydrogenate into feed zone of the first rectification column, into bottom of which hot jet and steam are fed. Top vapors of column are partly condensed in condenser and transferred into reflux tank, from the top of which vapors and from the bottom of which gasoline fraction are withdrawn. Hot jet is combined with hot hydrogenate and fed into feed zone of the first column. First-column side stream is fed into feed zone of the second rectification column. From the bottom of the latter, light fraction is withdrawn and top vapors are combined with those from the first column to be then condensed and collected in reflux tank. Part of gasoline fraction produced is used for refluxing the second column. EFFECT: increased yield of gasoline and reduced power consumption. 1 dwg, 1 tbl

Description

 The invention relates to the field of oil refining and petrochemical industries, specifically to methods for producing oil fractions.

 A known method of producing oil fractions, comprising introducing an unstable hydrogenate into a distillation column for stripping gas and gasoline fractions from hydrotreated diesel fuel (Smidovich E.V. Oil and gas processing technology, part 2-II, vol. 3, M .: Chemistry, 1980, p. 244).

 The prototype of the invention is a method for producing oil fractions by introducing heated hydrogenate into the feed zone of a distillation column, which works by supplying a hot stream and water vapor to the bottom of the column with output from the top of the steam column, partially condensing it in a condenser and feeding it to the irrigation tank with output from the top the last gas, and from the bottom - the gasoline fraction with the supply of part of it for column irrigation, with obtaining from the bottom of the column a stable diesel fraction (A. Fintrut et al. Chemistry and technology of fuels and oils. 1981, 11 , p. 34-37). With this method, there is a low selection of gasoline, high energy consumption and a new and high-quality distillate fraction is not obtained.

 The aim of the invention is to increase the selection of gasoline, reducing energy consumption and obtaining new and high-quality distillate fractions.

 This goal is achieved by the fact that in the method of producing oil fractions by introducing heated hydrogenate into the feed zone of the first distillation column, which works by supplying a hot stream and water vapor to the bottom of the column with the output from the top of the vapor column, partially condensing it in a condenser and feeding it to an irrigation tank with the conclusion from the top of the last gas, and from the bottom - the gasoline fraction with the supply of part of it for column irrigation, with the receipt of a stable diesel fraction from the bottom of the column, the hot stream is mixed with heated hydrogenate and put into the feed zone of the first column, from which lateral overhead is withdrawn and fed into the feed zone of the second distillation column, which works by supplying water vapor to the bottom of the column and withdrawing a light oil fraction from the bottom of the column, pairs from the top of the second column are mixed with pairs from the top of the first column and for the irrigation of the second column serves part of the gasoline fraction from the irrigation tank.

 The difference of the invention is that the hot stream is mixed with heated hydrogenate and introduced into the feed zone of the first column, from which the side stream is removed and fed to the feed zone of the second distillation column, which works by supplying water vapor to the bottom of the column and light oil withdrawal from the bottom of the column fractions, vapors from the top of the second column are mixed with vapors from the top of the first column, and a portion of the gasoline fraction from the irrigation tank is supplied for irrigation of the second column.

 In contrast to the methods known in science and technology, the proposed method by mixing a hot jet with heated hydrogenate and introducing the first column into the feed zone, withdrawing from the last side stream and feeding a second distillation column into the feed zone, working with water vapor being fed into the bottom of the column and the withdrawal of the light oil fraction from the bottom of the column, mixing the vapors from the top of the second column with vapors from the top of the first column and supplying part of the gasoline fraction from the irrigation tank for irrigation of the column allows to increase the extraction of gasoline, reduce energy consumption and get a new and high-quality distillate fraction without large additional capital costs.

 The drawing provides a diagram illustrating a method for producing oil fractions. Hydrotenizate feedstock is heated in heat exchangers 1 and introduced via line 2 into the feed zone of the first distillation column 3. Water vapor is supplied to the bottom of column 3 through line 4 for stripping light fractions. A stable diesel fraction is obtained from the bottom of column 3 through line 5, part of which is heated in heater 6 and returned to column 3 as a hot stream through line 7. Steam is discharged from the top of the column 3 through line 8, partially condensed in a condenser 9 and fed into the mixing vessel 10. Gas is discharged from the top of the tank 10 through line 11, and the gasoline fraction from the bottom along line 12, part of which is fed for irrigation columns 3. A hot stream (line 7) is mixed with heated hydrogenate (line 2) and introduced via line 14 into the feed zone of the first column 3, from which lateral overhead is withdrawn and fed through line 15 to the feed zone of the second distillation column 16, to the bottom of which line 17 serves water vapor. A light oil fraction is withdrawn from the bottom of column 16 through line 18. From the top of the second column 16 along the line 19, pairs are led out and mixed with pairs from the top of the first column 3 (line 8). For irrigation of the second column 16 through line 20 serves part of the gasoline fraction from the tank irrigation 10.

 The invention is illustrated by the following examples.

Calculations were carried out according to the proposed method and the prototype with the same total number of plates in the rectification system equal to 61. The mass and heat transfer efficiency of the plates was taken to be 0.5, which corresponds to a coefficient of efficiency relative to the theoretical plate 0.35. Raw material consumption 120 t / h. Its temperature after heat exchangers is 150 ^o C. The temperature of entry into the irrigation column is 60 ^o C, the hot stream is 244 ^o C, water vapor is an evaporating agent 340 ^o C. The top pressure of the column is 0.14 MPa.

Example 1 (by the proposed method). The numbering of input and output plates is shown in the drawing. Hydrogenated heated in heat exchangers in an amount of 120 t / h is introduced into the feed zone (between 15 and 16 plates, counted from the bottom) of the first distillation column, in which 41 plates are installed. The column operates with a flow of 100 t / h of a hot stream with a temperature of 244 ^o C. 2.5 t / h of water vapor are supplied to the bottom of the column. Steam is removed from the top of the column, partially condensed in a condenser at a temperature of 60 ^° C. and fed to an irrigation tank. From the top of the latter, 1.25 t / h of gas are discharged, and from the bottom 2.0 t / h of the gasoline fraction with a supply of 10.04 t / h of it for column irrigation. From the bottom of the column receive 110.75 t / h of a stable diesel fraction. A hot stream in an amount of 100 t / h with a temperature of 244 ^o C after the heater is mixed with heated hydrogen exchangers in a heat exchanger to a temperature of 150 ^o C; they are introduced into the feed zone of the first column, from 24 plates of which the side stream is removed and fed into the feed zone (between 13 and 14 plates) of the second distillation column. There are 20 plates in the column, and it works by supplying 0.5 t / h of water vapor to the bottom and withdrawing from the bottom 6.01 t / h of a light oil fraction (kerosene fraction). Vapors from the top of the second column are mixed with vapors from the top of the first column, and 1 t / h of the fraction from the irrigation tank is supplied for irrigation of the second column.

 The main operating parameters of the unit for stabilizing the hydrogenate of example 1 are presented in table.

 Example 2 (prototype). The process is carried out under the conditions of example 1 with the exception of mixing the hot stream with the heated hydrogenate and entering into the feed zone of the first column, withdrawing side stream from it and feeding into the feed zone of the second distillation column. The process is carried out in one distillation column having 61 plates, which is equal to the total number of plates in two columns according to the proposed method. A hot stream is introduced into the bottom of the column, from where a stable diesel fraction is removed in an amount of 116.98 t / h. 1.22 t / h of gas are discharged from the top of the column irrigation tank, and 1.8 t / h of gasoline fraction from the bottom.

 The main operating parameters of the unit for stabilizing the hydrogenate of example 2 are presented in table.

From the presented data it follows that in example 1 compared with example 2, the selection of gasoline increases from 1.8 to 2 t / h, that is, by 11.1%, energy consumption is reduced. The thermal load of the furnace for heating a hot stream decreases from 15.84 to 14.62 GJ / h, i.e. by 7.7%, the total consumption of water vapor for stripping light fractions decreases from 3.5 to 3.0 t / h, then there is 14.3%. It turns out a new light (kerosene) oil fraction in an amount of 6.01 t / h. In addition, the quality of the oil fractions improves. If in the prototype the gasoline fraction, despite the lower selection, was of poor quality at the end of boiling temperature (the content in it fr. 190 ^o C - since it was 13.41%), then in the proposed method it became qualitative (the content in it fr. 190 ^o C - KK decreased from 13.41 to 4.29 wt.%, More than 3 times). The content of light fractions in stable diesel fuel also decreased (H ₂ S from 7.1 • 10 ^-5 to 2.2 • 10 ^-5 , more than 3 times, fr.n.k.-190 ^o C from 6.47 up to 5.11%, 1.3 times, fr.n.k.-230 ^o C - from 31.25 to 27.98%, 1.1 times).

 Increasing the selection of gasoline, reducing energy consumption and obtaining new and high-quality distillate fractions makes it advisable to use the inventive method for producing oil fractions when producing oil fractions by mixing a hot stream with heated hydrogenate and introducing the first column into the feed zone, withdrawing from the last side stream and feeding into the feed zone of the second distillation column, which works by supplying water vapor to the bottom of the column and withdrawing a light (kerosene) fraction from the bottom of the column, mixing the vapors with PXA second column with the vapors from the top of the first column and feeding the second column for irrigation part of the gasoline fraction from the irrigation container.

 For example, the organization of work of only one hydrotreating unit according to the proposed method allows to obtain additionally up to 16 thousand tons / year of high-quality gasoline fraction and up to 48 thousand tons / year of light oil (kerosene) fraction and reduce energy costs.

Sources used
1. Smidovich E.V. Oil and gas processing technology. hours 2-11. Petroleum cracking and hydrocarbon gas processing. 3rd edition per. and add. -M .: Chemistry, 1980, p. 244.

 2. Fintrut A.I., Rudin N.G., Vasiliev A.V. Experience in the development and operation of LK-6u installations. Chemistry and technology of tops and oils. N1, 1981, p. 34-37.

Claims (1)

 A method of producing oil fractions by introducing a heated hydrogenate into the feed zone of the first distillation column operating with a hot stream and water vapor supplying to the bottom of the column, with steam output from the top of the column, its partial condensation in the condenser and supplying the last gas to the irrigation tank with the outlet from the top and from the bottom - the gasoline fraction with the supply of part of it for column irrigation, with obtaining from the bottom of the column a stable diesel fraction, characterized in that the hot stream is mixed with heated hydrogenate and introduced into the feed zone the first column, from which lateral overhead is withdrawn and fed into the feed zone of the second distillation column, which works by supplying water vapor to the bottom of the column and withdrawing a light oil fraction from the bottom of the column, the vapors from the top of the second column are mixed with vapors from the top of the first column, and for irrigation the second column serves part of the gasoline fraction from the irrigation tank.

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