DE2223513A1 - Process for the removal of butene-1 from hydrocarbon mixtures - Google Patents

Description

'Cologne, May 12th, 1972 Kl / Ax

Britannic House, Moor Lane, London, E.C.2Y 9BU (England) Process for removing butene-1 from hydrocarbon

mix

The invention relates to a method for removing 1-olefins, which contain more than 3 carbon atoms, from olefinic Hydrocarbons by simultaneous hydrogenation and isomerization, especially for the removal of 1-butene from mixtures containing 2-butene.

In certain cases it is desirable to increase the concentration of 1-olefins in olefinic hydrocarbon mixtures reduce to a minimum. For example, in the production of 2-methylbutene-2, an isoprene precursor, by codismutation of isobutene and butene-2 it is desirable to remove butene-1 contained in the starting material, and even more efforts are made to remove by isomerization of the double bond to butene-2 in order to To largely eliminate side reactions in the codismutation process. For isomerization of the double bond various methods have already been proposed. For the most part, however, these procedures are proportionate carried out at high temperatures, the displacement of the double bond due to equilibrium considerations is limited, so that the yield of 2-olefin is reduced «,

209848/1198

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The invention is a "at low temperature carried out process for the removal of 1-olefins from olefinic hydrocarbon mixtures by simultaneous Hydrogenation and isomerization, with the favorable equilibrium conversions of 1-olefins at low Temperatures can be used advantageously.

The process according to the invention for removing 1-olefins having more than 3 carbon atoms from hydrocarbon mixtures is characterized in that the starting material containing the 1-olefins is in the presence of hydrogen with a catalyst which is a noble metal of group VIII of the periodic Contains system according to Mendeleev, brought together at a temperature in the range from 0 ° to -70 ⁰ C.

As 1-olefins for which the process according to the invention butene-1, pentene-1, Hexene-1 and higher homologues, 3-methylpentene-1, 4-methylhexene-1, 4-phenylhexene-1 etc. in question. The procedure according to the invention is particularly suitable for the removal of butene-1, partly by isomerization to butene-2, from starting mixtures containing butene-2. Typical hydrocarbon mixtures produced by the method according to the invention can be treated contain saturated hydrocarbons, isobutene, butene-2 in the cis- and trans form, butene-1 and small amounts of other diolefins,

As noble metals of group VIII of the periodic system after Mendeleev come ruthenium, rhodium, osmium, iridium and platinum in question, with palladium being preferred. For the method according to the invention the metal is preferred applied to a suitable inert support. Aluminum oxide, for example, is suitable as a carrier. Palladium on aluminum oxide is preferred as the catalyst

209848/1198

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The catalyst advantageously contains 0.005 to 1.0 wt .- ^, preferably about 0.01 to 0.1 wt VIII «Group on the carrier. One for the purpose of the invention suitable commercial catalyst containing about 0.03 wt .- ^ palladium on aluminum oxide is from by Girdler Corporation, Louisville, Kentucky, USA (trade name "Catalyst G-55" described in Data Sheet G-55-562).

Another commercially available catalyst suitable for the purposes of the invention, which is about 0.05 wt .- ^ palladium on alumina is manufactured by Catalysts and Chemicals, Inc., Louisville, Kentucky (trade name "Catalyst C-31" described in Bulletin No. 0-31-053.

Hydrogen must be added to the starting material of the process according to the invention. The hydrogen will preferably admixed with the hydrocarbon mixture before being brought together with the catalyst. The mixed The amount of hydrogen is expediently in the range from 1 to 10 mol- ^, preferably 2 to 6 mol-? ».

The method according to the invention can be applied to any Pressures in the range from 0 to 14-0 bar (gauge pressure) can be carried out. Preferably at pressures im Range from 0 to 30 bar (gauge pressure) worked. The process can be carried out in the vapor phase or in the liquid phase will.

Is preferably carried out at temperatures in the range of +25 ⁰ C to -40 ° C. Surprisingly, as the temperature falls, the hydrogenation activity of the catalysts for olefins is suppressed and an effective isomerization of the double bond of the 1-olefins is achieved «

The room flow velocities calculated for the liquid state are expediently in the range from 0.1 to 30, preferably 1 "to 10 V / V / hour. Those for the gas state 209848/1138 - ^> H ^:.

calculated room flow velocities are expedient in the range from 20 to 6000, preferably 200 to 2000 V / V / hour "

example 1

A hydrogenated mixture of raffinate polyisobutene and raffinate butadiene containing less than 10 parts of butadiene per Million parts was used with a palladium-alumina catalyst (Girdler G-55A) among the following Treated reaction conditions:

Reaction pressure 21 bar (gauge pressure).

Space flow velocity

(calculated for liquid state) 2.0 V / V / hour.

Added amount of hydrogen: 4 mol # in the starting mixture Catalyst: 3 mm tablets, to a particle size of Ground 0.71 to 1.68 mm.

The results in the form of the composition of the starting mixture and the content of 1-butene in the n-butenes according to different running times and at different temperatures are given in Table 1 below.

Table 1

Reaction temperature, 0 0 product
after
589 hours -30 0.4 - mission Use product
after·
545 h - Components in ° / ° 0.4 2.2 propane 0.4 - 0.4 11.9 Propylene 0.1 2.4 0.1 0.5 Isobutane 2.0 14.1 2.0 41.1 η-butane 10.8 0.6 10.8 30.9 Butene-1 3.7 39.6 3.7 13.0 Isobutene 40.7 32.2 40.7 trans-butene-2 28.6 10.7 28.6 cis-butene-2 13.8 13.8

Butene-1 in the den

n-butenes 8.0 1.4 8.0 1.1

209848/1138

The results indicate that as the temperature decreases, the The proportion of 1-butene in the n-butenes is lower and the Proportion of butene-2 increases «,

Example 2

This example illustrates the effect of reaction pressure on butene-1 removal. In Table 2 are the composition of the starting material, the reaction conditions and the composition of the product two different reaction pressures are given.

Table 2

Influence of the reaction pressure on the removal of butene-1. Reaction temperature -10 ° C

Room flow velocity (based on liquid state) 2.0 V / V / hour.

Components in fo Mission, Product, 9b 1162 h running time 1107 h 7th Reaction pressure, bar
(Pressure gauge) 21st 0.5 C, + propane 0.5 0.5 2.3 i-C- + isobutane 2.0. 2.6 13.5 n-C. + n-butane 11.7 13.5 0.6 C.-1 butene-1 3.4 0.6 43.6 i-C. isobutene 44.3 44.2 28.7 -?
tC. trans-butene-2 25.5 28.5 10.8 _2
cC. cis-butene-2 12.6 10.1 1.5 Butene-1 in the
n-butenes, ° / o 8.2 1.5 83.7 Whole Butene, ^c / o 85.8 83.4 15.8 Total butane, ^c /> 13.7 16.1

Hydrogenation of butenes,

# 2.9 2.5

These results show that hydrogenation to butanes is less at a lower reaction pressure, while the content of remaining butene-1 remains unchanged »

2 0 9848/1198

Example 3

This example illustrates the influence of the space velocity on isomerization and hydrogenation. The composition of the raw material, the reaction conditions and the composition of the product at different space velocities are given in Table 3 below.

The results show that with decreasing space air velocity butene-1 removal increases and percent hydrogenation decreases.

209848/1198

Table 3

Influence of space flow velocity on isomerization and hydrogenation
Reaction temperature: " ^{λ0 /}
Reaction pressure:

-10 ^BC

Bar (gauge pressure)

3.0 M0I-9S E ₀ in the starting mixture

mission product mission
* product
ok mission product mission
ok product • 2.0 Room flow velocity
speed (calculated as gas),
V / V / h 2.0 3.5 5.0 7.6 7.8 Running time, hours 1162 1366 1502 1646 1.9 Components 50.1 propane 0.5 0.5 0.6 0.5 1.0 0.3 0.3 0.2 25.9 Propylene - - - - - - 0.2 12.1 Isobutane 2.0 2.3 2.1 2.1 2.3 1.6 2.3 4.8 n-butane 11.7 13.5 11.6 12.7 11.1 12.5 6.7 90.0 Butene-1 3.4 0.6 3.5 0.9 3.7 1.7 3.4 9.8 Isobutene 44.3 43.6 45.3 44.3 47.6 41.2 54.5 0.9 trans-butene-2 25.5 28.7 24.9 27.6 23.5 28.6 22.4 cis-butene-2 12.6 10.8 12.0 11.9 10.8 14.1 10.2 Butene-1 in total
bute ne η, ^c / o 8.2 1.5 8.7 2.4 9.7 3.8 9.5 Total butene, ok 85.8 83.7 85.7 84.7 85.6 85.6 90.5 Total butane, io 13.7 15.8 13.7 14.8 13.4 14.1 9.0 Hydrogenation of the butenes, $ - 2.5 - 1.3 - 0.8 -

Claims (13)

Patent claims Process for removing 1-olefins with more than 3 C atoms from hydrocarbon mixtures, characterized in that the outlet mixture containing the olefins in the presence of hydrogen with a catalyst which is a noble metal of the VIIIo group of the periodic System according to Mendelejef contains, "at one temperature merges in the range of 0 Ms -70 C. 2) Method according to claim 1, characterized in that mixtures "are treated, the butene-1, pentene-1, hexene-1, 3-methylpentene-1, 4-methylhexene-1 and 4-phenylhexene-1 as 1-olefins. 3) Process according to claims 1 and 2, characterized in that starting mixtures, the 1-butene as 1-olefin contain, "are treated. 4) Process according to Claims 1 to 3, characterized in that hydrocarbon mixtures are treated, the saturated hydrocarbons, isobutene, butene-2 in the cis and trans forms, butene-1 and small amounts of others Contain diolefins. 5) Process according to Claims 1 to 4, characterized in that catalysts are used which are used as noble metal of the VIII group contain ruthenium, rhodium, palladium, osmium, iridium or platinum, preferably palladium. 6) Process according to claims 1 to 5, characterized in that catalysts are used, which on a inert carrier are applied. 7) Process according to claims 1 to 6, characterized in that catalysts containing aluminum oxide as inert Carrier included, can be used. 2098Λ8 / 1193 8) Process according to Claims 1 to 7 »characterized in that catalysts are used which are 0.005 to 1.0 wt .- $, preferably 0.01 "to 0.1 wt .-? ·» Noble metal of the VIIIo group, based on the weight of the wearer, contain" 9) Process according to claims 1 to 8, characterized in that the starting mixture 1 to 10 M0I-7O, preferred ¹ jise 2 to 6 MoI- ^ hydrogen are added. 10) Process according to claims 1 to 9 »characterized in that that at a pressure in the range from O to HO bar, preferably 0 to 30 bar is worked. 11) Process according to claims 1 to 10, characterized in that it is carried out at a temperature in the range from 0 to -4O ⁰ C. 12) Process according to Claims 1 to 11, characterized in that the spatial flow velocity related to the liquid state in the range from 0.1 to 30, preferably in the range from 1 to 10 V / V / hour. lies. 13) Method according to claims 1 to 12, characterized in that the spatial flow velocity based on the gas state in the range from 20 to 6000, preferably from 200 to 2000 V / V / hour. lay 209848/1193