DE1443610A1 - Process for the production of alpha-olefins - Google Patents

Description

Process for the production of @ fon @ olefins.

The invention is based on a process for the production of # -Olefins by the "growth reaction" of a low molecular weight trialkylaluminum compound with a low molecular weight alkene.

In the process of producing + -olefins of high molecular weight by means of the growth reaction, this is achieved by converting a trialkylaluminum compound low molecular weight obtained with a low molecular weight alkene High molecular weight trialkyl aluminum in an exchange reaction with an alkene implemented low molecular weight. It is important to understand this reaction liquid phase, otherwise the alkylaluminum compounds the increased temperature of the reaction tend to decompose. The liquid phase will maintained by using a diluent or solvent. It is has been proposed for this purpose a saturated aliphatic hydrocarbon or to use a mixture of such hydrocarbons with a narrow boiling range. These solvents can then after the exchange reaction of the released Olefins are separated by distillation. In terms of preventing decomposition of the aluminum alkyl compounds show the saturated hydrocarbons satisfactory properties, but their use is due to this process unavoidable losses costly. From this round efforts have been made to find a better way of proceeding.

The invention therefore relates to the use of one in production hydrocarbon fraction recovered from # -olefins in the exchange reaction.

The invention also relates to a combination process which is the diluent required for the exchange reaction in the process elbot is formed.

Further trades and advantages of the invention will be derived from the following Description and explanation can be seen.

Invention regimen is an aluminum alkyl compound of low molecular weights with an alkene of lower molecular weights to an aluminum alkyl -Links High molecular weight including "growth product" implemented. The aluminum alkyl compounds are then in a KW-Frantion, which is above the decomposition temperature of the aluminum alkyl compound boils and prepared in the manner described below is subjected to the exchange or detachment reaction. This closes the exchange the high molecular weight alkyl group versus a low molecular weight alkene a. The # -olefin is formed from the detached alkyl radical. The one from the reaction resulting aluminum compound has a relatively low molecular weight. The reaction product is then subjected to a separation process to obtain the aluminum compound low molecular weight to remove. remaining KW material will be another Subjected to separation processes in order to obtain a high-boiling fraction, which contains the solvent used in the detachment reaction and the # -loefins. These Fraction can then be used as such as thinner amittal, or it can are subjected to a hydrogenation or isomerization reaction, by which the double bond is rehydrated b. z. ws moved from the @ position to another will.

The high boiling fraction is used as a diluent after or without treatment reused in the exchange section r.

The "growth reaction" includes the reaction of a mono-olefin or low molecular weight alkene, such as. Ethylene, propylene, butene, etc., with a trialkylaluminum whose alkyl substituents have 2 to 4 carbon atoms. The alternate product from this reaction consists of trialkyl compounds, the alkyl groups of which have a molecular weight which fluctuates over a wide range. The growth reaction can be represented by the following equation: Here x, y and z mean integers from 0 to about 14. The summer x + y + z is equal to a lower case "n". The growth reaction can then be carried out, then the mono-olefin, preferably in the presence of a diluent, is passed through the trialkylaluminum, such as triethylaluminum. The reaction conditions can be varied over a wide range.

The reaction temperature can be in the range of about 65 ibs 150 ° C and the pressure . range from about 14.2 to 352 atd. Usually an @ temperature in the Range from 90 to 120 C and a pressure between 70 and 246 atmospheres applied.

The statistical distribution of the length of the alkyl groups in the growth product is represented by Poisson's law of distribution: n-h m e p (n) nl.

Therein P (n) is the probability that by "n" additions of ethylene to the originally existing aluminum-ethyl bond a certain HC group is formed. "M" is the average number of additions of ethylene per growing chain. The table below explains that obtained in the growth reaction Distribution.

Alkyl group wt% C2 0.04 C4 0.23 C6 0.37 C8 11.79 C10 20.42 C12 22.63 C14 1.20 C16 11.61 C18 6.21 C20 3.47 C22 1.25 C24 0.59 C26 0.18 C28 0.05 Das The growth reaction diluent can be a paraffin, a cycloparaffin or a be more aromatic KW. Examples are: isooctane, cyclohexane, benzene, xylene and similar. The diluent supports the regulation of the reaction temperature, since the reaction is exothermic and serves as a solvent for the geliche at the same time Growth product. The previously mentioned treated or untreated Oefin can also be used as Diluents are used for the growth reaction. Line will be more detailed description will be given below.

The alkyl substituents of the growth product have 2 to 40 or even more carbon atoms. The growth product is in the exchange reaction with a low molecular weight Monoolefin implemented, which has 2 to 4 carbon atoms. As an example are to be mentioned : Ethylene, propene or butene. When exchanging or Detachment reaction becomes the high molecular weight alkyl group of the aluminum compound through the mono-olefin replaced. It thus follows that the product of the reaction trialkylaluminum compounds' theirs Alkyl groups have 2 to 4 carbon atoms, and # -olefins with 2 to 40 or contains more carbon atoms.

. The detachment reaction can mean in the absence of a catalyst the so-called Zurstäubtenchnit can be carried out. In such a procedure the starting material by means of known devices upon entry into the reaction zone atomized. The temperature is below 371 ° C, preferably between 37 and 371 ° C held. A temperature range of 204 to 330 ° C is particularly preferred. For the reaction is applied a pressure of below 14.1 atm. The reaction pressure can also be in the sub-atmospheric range, up to about 0.07 at. Is preferred a range from 1.42 to 7 at. The reaction time is in the range of 30 seconds up to 15 minutes, usually between 1 and 10 minutes, preferably between 3 and 7 minutes.

Various cones for atomizing the aluminum alkyl compounds Techniques are applied. For example, the conventional hollow gel spray en can be used. Dusting is achieved when there is a pressure differential along the nozzle is maintained. In some cases, the atomization of the aluminum alkyl compound supported by the use of a deadening gas. This can be done when executing of the process according to the invention be the alkene, which is used for the removal of the olefin is used. The introduction of the aluminum alkyl compound at an increased Temperature is desirable because of the reduction in viscosity. Generally will the aluminum alkyl * compound is preheated to a temperature below the reaction temperature, e.g. B. to about 343 °. Preference is given to atomization to about 87 to 320 ° C. prewarmed.

Used when the process is carried out non-catalytically without atomization of the starting material worked, a reaction temperature of 200 to 340 C preferred, with a range from 2.11 to 10.55 for the reaction pressure atü and a reaction time of 0.1 to 10 seconds is recommended.

The detachment reaction can also be carried out in the presence of a catalyst will. In this case, they are used as a precaution Reaction conditions a temperature of 50 to 150 ° C, a pressure of 21.1 to 105 atmospheres and a reaction time between 1 and 30 minutes. Suitable catalysts include the so-called Reduction catalysts such as nickel, cobalt, palladium and iron compounds. The preferred catalyst is a nickel compound which interacts with the trialkylaluminum compound reacted. The following may be mentioned: finely divided nickel metal, Raney nickel, nickel acetylacetonate, Nickel naphthenate etc., the amount of catalyst can vary over a wide range will. Usually, however, the catalyst is used in amounts of about 0.001 to 0.1 % used, based on the weight of the growth productase used in the reaction In the exchange reaction, the amount of alkene or mono-olefin used low molecular weight chosen so that the alkyl groups of the aluminum alkyl compound high molecular weight can be completely replaced. Correspondingly, the hono-olefin can be used in stoichiometric amounts, but the use of a stoichiometric Excess of 200 to 1000 mol% mono-olefin per mole of growth product with thermal Exchange or correspondingly 10 to 100 mol% preferred in the case of catalytic exchange.

There is also the possibility. part of the growth product in To convert alcohols. For this purpose, the growth product becomes the appropriate Aluminum alcoholates are oxidized, which are then subsequently hydrolyzed to the alcohols will. Any ot-olefins contained in the growth product can prevent oxidation be stripped off, the oxidation can be carried out using an oxygen-containing one Gas, i.e. air, oxygen, etc. can be carried out. The oxidation reaction can be done with or without the use of a solvent, but facilitated the use of a solvent makes the reaction run significantly. As a solvent is one (or more) of the above in connection with the growth or Exchange reaction mentioned inert hydrocarbon solvents can be used. However, it is for economic reasons it is advisable to use the same solvent for the oxidation to use which was previously used in the growth or exchange reaction. The use of a kerosene fraction with an initial boiling point is preferred from 176 to 204 ° C and an end boiling point of 259 to 271 C according to ASTM-borm. the Oxidation of the aluminum compound with an oxygen-containing gas can be used a temperature of 9 to 59 ° C, usually 18.4 to 68 ° C, and a pressure from 0.7 to 4.2, usually about 2.8 8 atm. These conditions can as well as the amount of oxygen-containing gas used for the gas according to the invention Verahran also considerably beyond the specified ranges can be varied.

The amount of oxygen used for the oxidation Gauss is determined on the basis of oxygen and normal conditions (0 ° C, 760 mm Hg).

A range from 27430 to 33080 is usually considered suitable vos 28700 to 31200 l / kg mole trialkylaluminum.

Following the oxidation treatment, the oxidation product can be used are hydrolyzed to the alcohols. The hydrolyzing agent can, for. Legs Mineral acid, such as sulfuric acid, or a basic agent, such as sodium or potassium hydroxide. The hydrolysis can also be carried out using water vapor but dilute sulfuric acid is preferred as the hydrolyzing agent. the Dilute sulfuric acid can contain about 20 to 30% by weight, preferably 24 to 26% by weight Sulfuric acid containm The oxidation product or the trialkoxides are 100 up to 120% gel%, usually treated with 103% to 110% by weight dilute sulfuric acid, based on the weight of the aluminum compounds. The hydrolysis is carried out at a Temperature from 71 to 100 ° C, usually from 79 to 78 ° C, and under a pressure of 0 to 7.5 atm, usually from 0 to 0.7.

In general, the reaction time is 0.25 to 2, as a rule but 0.25 to 0.3 hours. It can vary depending on the degree of conversion desired of alkoxy groups in alcohol molecules can be varied considerably.

Following the exchange reaction, the reaction product kit is a Subjected to separation processes to recover the # -olefins. The T of in the reaction product present # -olefins is determined by the Poisson's number. an "m" value of 3.5 to 4.5, which is common when carrying out the process of the invention it is found that about 3 to 5% of the # -olefins have at least 18 carbon atoms own. This fraction can be used as a diluent or solvent for the exchange reaction be used. For commercial reasons it may be desirable to have a parliamentary group to use which has at least 20 or so-called 22 carbon atoms per molecule. How to decide depends on the respective economic situation. The upper limit for the number of carbon atoms in the olefin is of course dependent on the "m" value. However, the number of carbon atoms can be 40 or. amount even more. Generally contains the fraction # -OIlefine with 18 to 40, 9 usually 20 to 40, but preferably 22 to 30 carbon atoms. # -olefins formed during processes can be used without further @treatment can be used as a diluent or solvent.

However, since the c-olsfins are somewhat reactive, they can also be isomerized will move the double bond from the # position to one further inside the molecule to move lying position. For this purpose, the fraction is referred to as isomerization treated with a catalyst containing alumina. This can be: clay gel, activated Tonewda, bauxite, etc., or a Silka clay, both synthetic than from natural vol-. such as acid-treated bentonite clay, silica-alumina gel etc., the latter substances containing about 0.5 to 30% by weight of silicon. The leomerization can at temperatures from 226 to 482 ° C, usually from 371 to 454 ° C and one Pressure from 0 to 7.4 atmospheres, usually from 0 to 0.7 atmospheres. The process can be carried out be carried out by means of a fixing or a moving bed. It will the starting material in an amount from 100 to 1000 or usually from 500 to 5000 kg introduced into the reaction zone per hour and per kg of catalyst.

Likewise, the # -olefins can also become saturated compounds be hydrogenated. For this purpose, the fraction with a hydrogen containing Gas, such as hydrogen, treated in the presence of a hydrogenation catalyst. Here you can any suitable catalysts are used, e.g. B. about nickel, chromium oxide, molybdenum oxide, Chromium ausflid, cobalt oxide, cobalt oxide, cobalt molybdate, nickel wofremat, etc., The Hydrogenation can be carried out in a moving or stationary bed, the hydrogen is in quantities of 70.8 to 283.3 m3 (at 0 ° C and 760 mm Hg) per hour into the reaction zone introduced. The introduction of the # -olefin into the reaction zone takes place in quantities from 0.05 to 10 kg per hour and kg of catalyst. The catalyst will either OAlB conditions are used in finely divided form or in the form of granules or pellets The ranges from 259 to 510 ° C and 7.4 to 745 apply to temperature and pressure atü.

The treated or untreated 40-olefins boil in an area that allows this spawns from the other process products to separate. This olefin fraction is used as a solvent for the exchange reaction in an amount of 10 to 50, usually 20 to 30 parts by volume per part by weight Aluminum alkyl compound used. The same amount can be used in the growth reaction can be used if desired. The solvent is used as part of the reaction product, containing the newly formed olefins, recovered. Part of the solvent however, it is lost and is replaced by sloping -olefin. All (-olefins, which about the Gained beyond the need of the mentioned betrayed are obtained as a bed product before they are, as described above, be treated.

The special performance when using a nickel catalyst. Gate for the isomerization of the high molecular weight O-olefins was established by a Preliminary test determined according to Example 1.

Example 1 The soil residue of a fractionated product a thermal: exchange reaction was used as the starting material. This consisted of 85% # -olefins. The lowest boiling point contained about 18 (the one on hochet = boiling about 40 carbon atoms. The rest of the material consisted of interior and branched olefins and from paraffins.

100 ml of this material were mixed with an H mixture of nickel naphthanate, activated with about 2% by volume of triethylaluminum, treated (Ni content 25 ppm).

The treatment time at 140 ° C. was about 1 hour. After this side the # -olsfin was almost completely isomerized so that the double bond was in one place was shifted inside the molecule.

The invention is best illustrated by the accompanying drawings According to Fig. 1, about 2.27 kg of fresh triethylaluminum are from stock 5 per hour countersunk and with trithylaluminum to be used again in the reaction, which over 6 is fed in amounts of about 43 kg per hour, mixed. This mixture is fed to the growth reactor 9 via line 7 via line 10 in the 49.9 kg of ethylene and via line 11 45.3 kg of one as a solvent serving ismerized fration. The growth rack gate is under a pressure of 105.5 atü kept at a temperature of 118 ° C. The residence time for the reaction mixture amounts to 3 hours, an "m" value 4 results for the urge to move.

The Wucha product leaves the reactor via line 14 and is in given a reactor 15 for the thermal exchange reaction. In this @eaktor 367.4 kg of ethylene are imported from stock 16 per hour. In the reactor for The catalytic exchange creation is a pressure of 31.7 atü and a temperature kept at 110 ° C. The reaction tray has a residence time of 3 minutes. Under Under these conditions in reactor 15, all of the alkyl groups in the aluminum alkyl compounds become of the growth product exchanged for ethylene. The product leaves the reactor 15 via line 17 and enters the device 18 for removal of triethylaluminum. This procedure is described in detail below with reference to Fig. 2 described. It should be noted that these are used as solvents isomerized fraction has a higher boiling point than triethylaluminum, so that its separation can take place. The recovered triethylaluminum is returned to the usury reactor via line-6. The rest of the product passes from the device 18 via line 19 into the distillation column @@ 21.

The olefins, which have no more than 20 carbon atoms, leave the distillation column as the Obenaus fraction via line 22. The olefins with at least 22 carbon atoms and the isomerized fraction are discharged via the bottom line 23. The top temperature in the column is 231.degree. C. and the bottom temperature is 330.degree held.

A part of the # -lefins with at least 22 C-atoms from this system is discharged via line 25. The remaining part is via line 26 into an isomerization reactor 27 given. This contains granulated bauxite.

The Ulefine is fed in at a rate of 4.53 kg / hour. This corresponds to a throughput of 100 kg / hour and kg of catalyst. The reaction temperature is 121 ° C at 0 atmospheric pressure. The isomerized product is tubez line 11 from discharged from the reactor 26 and returned to the growth reactor.

Fig. 1 also shows 2 additional and modified embodiments of the Invention. In one embodiment, the high molecular weight fraction is the Olefins from distillation column 21 as solvents for the exchange reaction used without additional treatment. The transfer into the reactor takes place lengthways the dashed line 28. In the other embodiment, said olefin fraction given from the distillation column 21 via line 23 into the hydrogenation reactor 29, where the olefires in the presence of a nickel @ aphthaneate catalyst at 140 ° C approximately be hydrogenated for one hour. The product of the hydrogenation is via line 30 (dashed) given in the growth reactor.

If part of the growth product is used for the production of alcohols, the system is preferably operated in such a way that the isomerization action only for the exchange reaction is used. The solvent for the growth reaction can then a saturated aliphatic hydrocarbon, e.g. B. kerosene, so can the solvent as such in the Oxidation used will. In this reaction, the alkyl compounds of aluminum are converted into corresponding Converted alkoxy compounds. This system is illustrated by FIG.

In Fig. 2, kerosene has an initial boiling point of 149C and a final boiling point of 218 ° C via line 31 in amounts of 45.3 kg / hour. in n a growth reactor 30 given. 2. k27 kg of triethylaluminum from 32 are put into the reactor as a substitute amount introduced. Via line 33 you give 43 k'i. trumza .. and a izewinu. gso stu. iy she. de t be ac. z t. the e. r r! 34 united. 'be si "' crda. g k. y c ° uacie 1.. a dn Fa, r @? ae x3a ° u a ak. d t E ° z or ruk li ~ twa ts 5 e Da U eE; r7. o! °° & a 'a3tug ~ to Tel will be:. Tr;,. ~ av $ szrd r Leizarrr: . n qh gt; ); ; abri; a. ! : - '; f. W ate ° uxa. e il 'Naap = o e; ia igen from 45.3 kg in Dar hour in Strippe 40. In this, a Drek lz:, sz t I. r p. j'96C. exaaas. s i: 7e; xae r'r saa =. Cna-ti $:, aB,. : ir, er £ ir 1-. n @@ onn that is desired, an ordinary gaseous HC material as Can be used from @@ reifgam. the kerosene solvent is sucked off via line 41, the solvent-free growth product via line 42. The growth product is ukt now with the isomized fraction, change via line 43 in Mewngen of 11.3 kg is brought up in the hour, united and over Le g as C e; 3. a. et: 4 f hs. The thermal exchange reaction is now in the presence of the isomerized # -olofin fraction and not in the presence of the krosine solution medium executed. Usually, kerosene has a boiling range that is too wide to be used by don en olefins formed in the exchange reaction to be able to be separated. In the Reactor 46 is introduced via line 48 ethylene (72.48 kg / hour) into reactor 46 the temperature is gehlten at 121 ° C and the pressure at 31.6 atü. The reaction proceeds within 3 minutes. This is sufficient, M all alkyl groups of the aluminum alkyl compound replaced by ethylene. The reaction product pass through line 49 from the Reactor 46 in lie device 50 for the recovery of triethylaluminum, where the latter ab - @@ separates.

The device 50 consists of two deetillation columns connected in series. In the first column the # -olefin is separated into two fractions with taine urate the olefins, which have 10 or fewer carbon atoms, and a second, which aua part of the C10 olefin, the high forming olefins and triethylaluminum consists. In the second distillation kettle, the above fraction consists of one Yeil of the C12 - @ - olefin and triethylaluminum, while the bottom fraction is the # -olefins contains which are difficult to sine than the C14 olefin. In the first Kolenxe lies the Lpp temperature at 101 ° C and the bottom temperature at 110 ° C. At the wide column if the top temperature is 110 ° C, the bottom temperature is 330 ° C. These colonies is kept under vacuum. The device 50 becomes the # -olefin stream, which is heavier than C12, discharged via line 51. The faction that is in a hurry which contains C12 olefins and triethylaluminum is discharged via line 33 and returned to the growth reactor.

The # -olefin fraction in line 51 goes to a distillation column 54.Drau, as Obanaus fraction, the olefin fraction is discharged via line 55, which contain the olefins with not more than 20 carbon atoms The heavier olefins are obtained as the bottom fraction via line 56.

A portion of the heavier olefins is removed from the system (at 9.6 kg / hour) removed. The remaining part reaches the isomer reactor 59 via line 58. The operating conditions for the distillation column 54 and the isomerization reactor 59 are practically the same as for the distillation column 21 and d 4 * tor 26 in general the execution of the process macs Fig. 1. The isomerized olefins from the reactor 59 was via line 43 in the reactor 46 for the thermal exchange reaction leads back.

Claims (11)

Patentasmpr @ che @ 1. Method of making 040lefinthereby characterized that a trialkylaluminum compound of low molecular weights with an alkene of low molecular weights in a growth reaction to a trialkylaluminum compound high molecular weights implemented the trialkylaluminum compound of high molecular weight in the presence of a solvent designated below in an exchange reaction with an alkene of lower molecular weights to an outer one of a trialkylaluminum compound lower molecular weights, # -olefins lower and # -olefins higher molecular weights The remaining product is reacted and the trialkylaluminium V @@ bond has low molecular weights is separated from the reaction product, whereupon a Low molecular weight fraction of # -olefins and a fraction of # -olefins can be separated with high molecular weight and the latter as dolce or after partial or more complete = hydrogenation or isomerization than the solvent mentioned is used for the exchange reaction. 2. The method according to claim 1, characterized in that said LU-solvent for the exchange reaction at least 20 carbon atoms in the molecule Owns. 3. The method according to claim 1, characterized in that the exchange reaction is a thermal reaction. 4. The method according to claim 1, characterized in that for the A solvent is used in the growth reaction. 5. The method according to claim 4, characterized in that the Loaungmittel is a saturated aliphatic hydrocarbon, which prior to corrosion of the product the growth reaction is separated into the exchange reaction. 6. The method according to claim 5, characterized in that the saturated aliphatic hydrocarbon is a kerosene fraction. 7. The method according to claim 1 and 4, characterized in that the Solvent for the growth reaction said solubilizing agent for the exchange reaction is. 8. The method according to claim 1, characterized in that the in the growth reaction used trialkylaluminum compound is triethylaliminium. 9. The method according to claim 1q, characterized in that in the The low molecular weight alkene used in the growth reaction is ethylene. 10. The method according to claim 1, characterized in that the in the low molecular weight alkene used in the exchange reaction is ethylene. 11. The method according to claim 1, 2, 8, 9 and 10, characterized in that that triethylaluminum with ethylene to a growth product with 2 to 40 carbon atoms the growth product obtained is reacted in the alkyl groups with ethylene in the presence of an isomerized # -olefin with at least 22 carbon atoms in the molecule Triethylaluminum and olefins with 2 to 40 carbon atoms in the molecule is, from the reaction product triethylaluminum and the «-olefins with 6 to 10 Carbon atoms are separated and from the remaining reaction product the Olefin fraction with more than 22 carbon atoms in the molecule separated, then isomerized and reused as a solvent for the exchange reaction.