SU1313846A1 - Method for removing acetylene hydrocarbons from butadiene fractions - Google Patents

Abstract

The invention relates to petrochemistry, in particular, to a method for purifying oil containing fractions from acetyl hydrocarbons by catalytic hydrogenation, and can be used in the management of butadiene obtained by butane dehydrogenation. Reduced loss of butadiene, i.e. an increase in the selectivity of the process is achieved due to the fact that hydrogen is divided into two streams in a mass ratio of 1: 4-20. The first stream of hydrogen is fed to the mixer, where the butadiene-containing fraction is also sent. The latter, with dissolved hydrogen from the mixer, is fed to the hydrogenation reactor. The second stream of hydrogen is introduced into the hydrogenation reactor either in one zone or evenly distributed in several zones. From the hydrogenation reactor, hydrocarbons and unreacted hydrogen: are diverted for further processing. Moisture accumulating in the mixer to increase the service life of the hydrogenation catalyst is removed. Hydrogenation is carried out using nickel on diatomaceous earth as a catalyst, containing 50 wt.% Nickel or 0.5 wt.% Palladium on alumina at a temperature of 10 and 20 ° C, respectively, and a molar ratio of hydrogen and acetylene hydrocarbons 50: 1. The method allows to reduce the loss of butadiene by 6.8 kg per 1 ton of marketable butadiene (0.15-0.2 abs.%). 1 silt, 1 tab. (L from: from from 00 4 О5

Description

113

The invention relates to petrochemical synthesis, in particular to the purification of butadiene-containing fractions from acetylenic hydrocarbons by catalytic hydrogenation, and can be used in the isolation of butadiene produced by butane dehydrogenation.

The aim of the invention is to reduce the loss of butadiene by increasing the selectivity of the process.

The drawing is a schematic diagram of the implementation of the proposed method.

Pipeline 1 sends the butadiene-containing fraction to mixer 2. On line 3, a portion of the hydrogen is introduced into the same apparatus. Most of the hydrogen through line 4 is fed to the hydrogenation reactor 5. Along line 6, the butadiene-containing fraction with dissolved hydrogen is sent to the hydrogenation reactor 5. Through pipeline 7, hydrocarbons and unreacted hydrogen are diverted to further processing. The accumulated moisture in apparatus 2 is removed via line 8. This prolongs the service life of the hydrogenation catalyst.

The invention is illustrated by the examples below.

PRI me R s 1-3. The butadiene-containing fractions are purified according to the proposed method in accordance with the above scheme. The process is carried out at a total molar ratio of hydrogen: hydrogenated fraction of 0.0245: 1 (total hydrogen consumption in the mixer and the hydrogenation reactor is 3.5 kg / h), the molar ratio of hydrogen: acetylene hydrocarbons is 50: 1. Nickel on kieselgur is used as catalyst. brand H, the Nickel content of 50 wt.%. The mass ratio of the streams of aide to the mixer and the hydrogenation reactor for examples 1-3 is 1: 4, 1:12, and 1:20, respectively. The hydrogenation reaction is carried out at a space velocity of 2 to 5 hours and a temperature of 10 ° C.

Examples 4-5. The cleaning process is carried out as in examples 1-3, with the difference that the mass ratio of hydrogen flows to the mixer and the hydrogenation reactor for example 4 is 1: 3, and dp of example 5 is 1:25.

The main indicators of the cleaning process in examples 1-5 are shown in the table.

It follows from the table that at the optimum ratio of hydrogen streams sent to the mixer and the hydrogenation reactor, 1:12 (example 2), the loss of butadiene during hydrogenation will be 52.4 kg per 1 ton of butadiene withdrawn from the hydrogenation reactor. When the entire hydrogen stream is fed into the hydrogenation reactor, the loss of butadiene is 62 kg per ton of butadiene withdrawn from the reactor.

The loss of butadiene per ton of commodity butadiene is 37.4 kg. Reducing the loss of butadiene compared with the supply of the entire hydrogen stream to the hydrogenation reactor of 6.8 kg per 1 ton of marketable butadiene.

EXAMPLE 6 The process is carried out as in Examples 1-3, with the difference that 0.5% by weight of palladium on alumina is used as a catalyst with a preliminary dissolution of 0.18 mol / h of hydrogen in a butadiene detector. - the feed fraction in the mixer and the supply of the remaining hydrogen in the amount of 0.72 mol / h to the inlet of the hydrogenation reactor. Hydrogenation is carried out at 20 C and a pressure of 7 atm. In this case, the loss of butadiene is reduced compared with the supply of the total amount of hydrogen to the hydrogenation reactor from 4.4 to 4.1 rel.%.

Example 7. The process is carried out under the conditions of example 6 with the distribution: and the total amount of hydrogen.

1.7 mol / h as follows: 0.13 mol / h into the mixer, the rest of the amount is evenly distributed into 8 zones of the hydrogenation reactor. With

this loss of hydrogen is reduced to

1.8 vol.% Compared with the supply of the total amount of hydrogen in 8 zones of the reactor (2.0 rel.%),

Claims (1)

jg formula invented The method of purification of butadiene-containing fractions from acetylene hydrocarbons by catalytic hydrogenation of hydrogen, characterized in that, in order to reduce the loss of butadiene, hydrogen is divided into two streams in a mass ratio of 1: 4-20, the first stream of hydrogen is preceded by It is dissolved in butadiene hydrogenation, and a second stream of hydrogen from the holding fraction is fed to the hydrogenation before being fed. I Indicators of the process of purification of butadiene-containing hydrocarbons Acetylene hydrocarbons 1.92 0.32 0.32. 0.32 0.32 0.32