CN102240563B

CN102240563B - Alpha-olefin oligomerization immobilized catalyst and preparation and application thereof

Info

Publication number: CN102240563B
Application number: CN201010174749XA
Authority: CN
Inventors: 黄付玲; 米普科; 王斯晗; 韩雪梅; 张宝军; 钱锦华; 刘敏; 江玲; 李建忠; 张祥良; 陈谦; 高飞; 谷振生; 卢攀峰; 王桂芝; 刑士轩; 韩云艳; 王亚丽; 孙淑坤; 高宇新
Original assignee: East China University of Science and Technology; Petrochina Co Ltd
Current assignee: East China University of Science and Technology; Petrochina Co Ltd
Priority date: 2010-05-12
Filing date: 2010-05-12
Publication date: 2013-04-24
Anticipated expiration: 2030-05-12
Also published as: CN102240563A

Abstract

本发明涉及一种α-烯烃齐聚固载催化剂及其制备和应用；该催化剂以γ-氧化铝为载体，负载有三氯化铝和第Ⅷ族过渡金属盐，按重量百分比催化剂成分如下：铝：2.5～6.0％、氯：6.0～12.0％、第Ⅷ族过渡金属：0.5～5.0％、扣除SO₄ ^2-和/或NO₃ ^-外其余为γ-氧化铝；第Ⅷ族过渡金属为铁、钴、镍或铜；该固载催化剂催化1-癸烯或1-辛烯的齐聚反应表现出高活性和高稳定性，克服了三氯化铝催化剂的强腐蚀性，易与产物分离，避免了三氯化铝催化剂所产生的大量污水及环境污染问题。The invention relates to an α-olefin oligomerization immobilized catalyst and its preparation and application; the catalyst uses γ-alumina as a carrier, loaded with aluminum trichloride and Group VIII transition metal salt, and the catalyst components are as follows in weight percentage: aluminum : 2.5～6.0%, Chlorine: 6.0～12.0%, Group VIII transition metal: 0.5～5.0%, except SO ₄ ^2- and/or NO ₃ ^- , the rest is γ-alumina; Group VIII transition metal is iron , cobalt, nickel or copper; the solid-supported catalyst catalyzes the oligomerization reaction of 1-decene or 1-octene, exhibits high activity and high stability, overcomes the strong corrosion of aluminum trichloride catalyst, and is easy to separate from the product , to avoid a large amount of sewage and environmental pollution problems produced by the aluminum trichloride catalyst.

Description

A kind of supported catalyst for alpha-olefin oligomerization and preparation thereof and application

Technical field

The present invention relates to gama-alumina solid-carried catalyst of a kind of 1-of being applicable to decene or the oligomerisation of 1-octene and its preparation method and application.

Background technology

AlCl ₃Catalyst is a kind of lewis acid catalyst, has in catalysis alpha-olefin oligomerisation reaction that polymer yield is high, a narrow molecular weight distribution, the selective characteristics such as good; But AlCl ₃Catalyst has severe corrosive, easily the devices such as reactor is damaged, and affects the service life of device, thereby has reduced utilization rate, simultaneously AlCl ₃Catalyst can produce large amount of sewage, such as untimely processing meeting serious environment pollution, and reacted AlCl ₃Catalyst is difficult to reclaim, and needs through post processing, otherwise can produce a large amount of corrosivity waste materials.

In order to reach the requirement of Green Chemistry, replace AlCl at solid acid catalysts such as exploitation load metal oxides ₃, BF ₃Etc. the traditional catalyst time, also making great efforts research AlCl ₃Solid-supported catalyst.Hope can keep AlCl ₃Under the prerequisite of good characteristic, the problems such as the corrosion that solution exists and environmental protection make it change environment amenable catalyst into.Support type AlCl ₃Catalyst is a kind of efficient, eco-friendly novel solid acid catalyst, owing to having higher catalytic activity and gentle reaction condition, receives much concern in recent years, is widely used in the research of polymerization and alkylated reaction.

Patent US 2,927, and 087 proposes the earliest, can pass through AlCl ₃Steam with make AlCl with the reaction of the refractory oxides such as the aluminium oxide of surface hydroxyl, silica ₃Solid-supported catalyst purges with carrier gas being higher than under 300 ℃ the temperature after emphasizing to react, and removes unreacted AlCl ₃Necessity.

USP 4,929, and 800 with CCl ₄, CH ₃Cl or CH ₂Cl ₂Deng being solvent, the alchlor dissolving wherein, add the carriers such as silica or aluminium oxide, at 50～80 ℃ and N ₂Protection, lucifuge condition flow a few hours next time to a few days, can make the very high catalyst of alkane isomerization or lytic activity.

Patent USP 6,002, and 060 points out, take the support type alchlor as catalyst, organo-aluminum compound is auxiliary agent, can make alpha-olefin generation oligomerisation or copolyreaction.

CN1156338 and CN1939590 utilize the gas phase solid support method under the N2 carrier band, fresh alchlor to be brought into to have mesoporous and reaction tube that the granularity macropore double-pore structure is 20～200 order aluminium oxide in react, prepare AlCl ₃Solid-supported catalyst, wherein chlorinty is 6.0～9.0 ω %.This carried catalyst has good catalytic activity and selective in isobutene polymerisation, show good stability.But in the fixed bed reaction of filling finely grained catalyst, there is obvious Pressure Drop problem.

Summary of the invention

The objective of the invention is gama-alumina solid-carried catalyst that discloses a kind of 1-of being applicable to decene or the oligomerisation of 1-octene and its preparation method and application.Supported catalyst catalysis 1-decene of the present invention or 1-octene oligomerisation reaction activity are high, and product separation is easy, the recyclable recycling of catalyst, environmental contamination reduction; Avoid the corrosion of homogeneous catalyst to reactor, also avoided halid existence in the 1-decene oligomerization product simultaneously.

Catalyst component is as follows by weight percentage:

Aluminium: 2.5～6.0%

Chlorine: 6.0～12.0%

VIII group 4 transition metal: 0.5～5.0%

Deduction SO ₄ ^2-Or/and NO ₃ ^-All the other are gama-alumina outward;

The VIII group 4 transition metal is iron, cobalt, nickel or copper.

The preparation method of supported catalyst of the present invention is as follows:

1) gamma-aluminium oxide carrier is carried out the acidifying impregnation process: actual conditions is: under the room temperature, gamma-aluminium oxide carrier was flooded 4～12 hours in hydrochloric acid, sulfuric acid, nitric acid or their mixture solution of 0.5～2.0M, then 80～100 ℃ of vacuum drying 2～12 hours;

2) gamma-aluminium oxide carrier with acidifying carries out VIII group 4 transition metal salt impregnation process: actual conditions is: under the room temperature, the gamma-aluminium oxide carrier of acidifying was soaked 6～12 hours in the sulfate of VIII group 4 transition metal iron, cobalt, nickel or the copper of 0.5-3.0M or nitrate solution, then 80～100 ℃ of vacuum drying 2～12 hours; Under 300～800 ℃, carry out again high-temperature roasting 6～16 hours;

3) alchlor is carried out solution immobilized: will 5～10g aluminum trichloride (anhydrous) add in 100ml carbon tetrachloride, chloroform or the dichloromethane solvent and make solution, join in the gamma-aluminium oxide carrier after 10～20g activates, under reflux temperature, kept 6～24 hours, desolventizing, wash with n-hexane, obtain after the vacuum drying take gama-alumina as carrier, load has the catalyst of alchlor and VIII group 4 transition metal salt.

In the preparation of supported catalyst of the present invention, gamma-aluminium oxide carrier is ball-aluminium oxide carrier or bar shaped alumina support; Spherical gamma-aluminium oxide carrier diameter is 1.3～2.3mm, preferred 1.5～2.0mm, specific area 100～180m ²/ g, preferred 120～160m ²/ g, total pore volume 〉=1.0ml/g, strip carrier diameter 3mm, length is 4～10mm, preferred 5～8mm, its specific area is 100～200m ²/ g, preferred 140～180m ²/ g, total pore volume 〉=0.6ml/g.

Optimum acid is hydrochloric acid during the gamma-aluminium oxide carrier acid treatment, and suitable concentration of hydrochloric acid is 0.5～1.5M, and suitable dip time is 4～8 hours; Optimum transition metal salt was nickel nitrate or nickelous sulfate when the gamma-aluminium oxide carrier of acidifying flooded the VIII group 4 transition metal, suitable nickel nitrate solution concentration is 0.5-3.0M, or nickel sulfate solution concentration is 0.25-1.5M, and suitable dip time is 6～12 hours.Then 80～100 ℃ of vacuum drying 2～12 hours; Under 300～800 ℃, carry out again high-temperature roasting 6～16 hours.400 ℃ of optimum calcination temperatures, roasting time 12 hours.

In the preparation of supported catalyst of the present invention, optimum solvent is that carbon tetrachloride or carbon tetrachloride and chloroform volume ratio are 1: 1 mixed solvent during the load aluminum trichloride (anhydrous), best return time 12 hours.

Utilize the preparation method of supported catalyst of the present invention, the chlorinity of the load aluminum trichloride catalyst that finally makes is 6.0～12 ω %, aluminium: 2.5～6.0 ω %, VIII group 4 transition metal (iron, cobalt, nickel, copper): 0.5～5.0 ω %, deduction SO ₄ ^2-, NO ₃ ^-All the other are gama-alumina outward.

In the preparation of this catalyst, all courses of reaction all are to carry out under the inert gas shielding condition, and inert gas is nitrogen or argon gas.

Supported catalyst of the present invention is applied to catalysis 1-decene or 1-octene oligomerisation reaction, makes 1-decene or 1-octene oligomer.Its principle is according to the cationic oligomer reaction principle, adopts Lewis acid catalyst and promoter to form the complex catalysis system.The present invention is used as 1-decene or 1-octene oligomerisation reaction catalyst; 1-decene or 1-octene oligomerisation reaction are take n-hexane as solvent, and 1-decene or 1-octene and n-hexane volume ratio (3: 8)～(4: 1) are to react under 0.8～1.4MPa condition 5～6 hours in 80 ℃～120 ℃ of temperature, reaction pressure; Then stop reaction, filtering catalyst, air-distillation desolventizing n-hexane, unreacted monomer 1-decene or 1-suffering and part dimer are removed in decompression distillation, obtain the oligomer of final 1-decene or 1-octene.

1-decene conversion ratio 〉=50 ω %, 100 ℃ of kinematic viscosity 〉=3.46mm ²/ s.

The 1-decylene oligomer that the present invention obtains meets the requirement of lube base oil viscosity, and the quality of oil product is high.

The present invention can reduce the chlorinity in the product by heterogeneousization of polymerization system, makes catalyst can separate, recycle and reuse, environmental contamination reduction with product.

The specific embodiment

Embodiment 1

Spherical gamma-aluminium oxide carrier carries out the acidifying impregnation process: at room temperature, (the carrier diameter is 1.3～2.3mm, specific area 100～180m with spherical gamma-aluminium oxide carrier ²/ g, total pore volume 〉=1.0ml/g) in the hydrochloric acid solution of 1.0M, flooded 6 hours, again 80～100 ℃ of vacuum drying 12 hours.

VIII group 4 transition metal salting liquid is immobilized: at room temperature, the spherical gamma-aluminium oxide carrier of acidifying impregnation process was flooded 6 hours in the 0.5M nickel nitrate solution, then 100 ℃ of vacuum drying 12 hours.Under 400 ℃, carry out at last high-temperature roasting 6 hours.

Aluminum trichloride solution is immobilized: under argon shield; the 5g aluminum trichloride (anhydrous) is made solution in the 100ml carbon tetrachloride; join in the alumina support after 10g activates; under reflux temperature, kept 24 hours; desolventizing; with the n-hexane washing, obtain the alchlor supported catalyst after the vacuum drying.

By the Fo Erhade titration above-mentioned alchlor supported catalyst is carried out chloride content determination, get that chlorinity is 6.73 ω % in the supported catalyst; Survey metallic nickel, aluminium content with atomic absorption spectrum, nickel content is 0.67 ω %, and load aluminium content is 3.46 ω %.

The oligomerisation of catalysis 1-decene: in the 250ml polymerization autoclave, add n-hexane 80ml, above-mentioned supported catalyst 8g, 1-decene 30ml, co-catalyst water 0.0936mol (co-catalyst/-AlCl ₂Mol ratio=0.90), under 80 ℃ of reaction temperatures, reaction pressure 1.0MPa condition, carried out 1-decene oligomerisation reaction 5 hours.Stop reaction, filtering catalyst, through normal pressure distillation desolventizing n-hexane, unreacted monomer 1-decene and part dimer are removed in decompression distillation, obtain final oligomer.1-decene conversion ratio 43.6 ω %, 100 ℃ of kinematic viscosity 3.46mm of oligomer ²/ s.

Embodiment 2

The preparation of load aluminum trichloride catalyst and catalysis 1-decene oligomerisation step condition are with embodiment 1, and difference is that the vehicle treated condition is: spherical gamma-aluminium oxide carrier was flooded 4 hours in the hydrochloric acid solution of 1.5M, again 80～100 ℃ of vacuum drying 12 hours; VIII group 4 transition metal salting liquid is immobilized: the spherical gamma-aluminium oxide carrier of acidifying impregnation process was flooded 6 hours in the 2.0M nickel nitrate solution, then 100 ℃ of vacuum drying 12 hours.

By the Fo Erhade titration above-mentioned alchlor supported catalyst is carried out chloride content determination, get that chlorinity is 8.45 ω % in the supported catalyst; Survey metallic nickel, aluminium content with atomic absorption spectrum, nickel content is 4.27 ω %, and load aluminium content is 3.45 ω %.

The oligomerisation of catalysis 1-decene records 1-decene conversion ratio 58.3 ω %, 100 ℃ of kinematic viscosity 6.64mm of oligomer ²/ s.

Embodiment 3

The preparation of load aluminum trichloride catalyst and catalysis 1-decene oligomerisation step condition are with embodiment 1, and difference is that the vehicle treated condition is: spherical gamma-aluminium oxide carrier was flooded 6 hours in the hydrochloric acid solution of 1.0M, again 80～100 ℃ of vacuum drying 12 hours; VIII group 4 transition metal salting liquid is immobilized: the spherical gamma-aluminium oxide carrier of acidifying impregnation process was flooded 6 hours in the 1.0M nickel nitrate solution, then 100 ℃ of vacuum drying 12 hours.

By the Fo Erhade titration above-mentioned alchlor supported catalyst is carried out chloride content determination, get that chlorinity is 7.95 ω % in the supported catalyst; Survey metallic nickel, aluminium content with atomic absorption spectrum, nickel content is 1.53 ω %, and load aluminium content is 4.57 ω %.

The oligomerisation of catalysis 1-decene records 1-decene conversion ratio 52.7 ω %, 100 ℃ of kinematic viscosity 5.29mm of oligomer ²/ s.

Embodiment 4

The preparation of load aluminum trichloride catalyst and catalysis 1-decene oligomerisation step condition are with embodiment 3, and difference is that VIII group 4 transition metal salting liquid is immobilized: replace nickel nitrate solution with nickelous sulfate.

By the Fo Erhade titration above-mentioned alchlor supported catalyst is carried out chloride content determination, get that chlorinity is 8.28 ω % in the supported catalyst; Survey metallic nickel, aluminium content with atomic absorption spectrum, nickel content is 3.21 ω %, and load aluminium content is 4.31 ω %.

The oligomerisation of catalysis 1-decene records 1-decene conversion ratio 59.1 ω %, 100 ℃ of kinematic viscosity 6.13mm of oligomer ²/ s.

Embodiment 5

The preparation of load aluminum trichloride catalyst and catalysis 1-decene oligomerisation step condition are with embodiment 4, and difference is that VIII group 4 transition metal salting liquid is immobilized: replace nickel sulfate solution with copper sulphate.

By the Fo Erhade titration above-mentioned alchlor supported catalyst is carried out chloride content determination, get that chlorinity is 10.68 ω % in the supported catalyst; Survey metallic copper, aluminium content with atomic absorption spectrum, copper content is 2.57 ω %, and load aluminium content is 4.04 ω %.

The oligomerisation of catalysis 1-decene records 1-decene conversion ratio 57.7 ω %, 100 ℃ of kinematic viscosity 9.85mm of oligomer ²/ s.

Embodiment 6

The preparation of load aluminum trichloride catalyst and catalysis 1-decene oligomerisation step condition are with embodiment 4, and difference is that VIII group 4 transition metal salting liquid is immobilized: replace nickel sulfate solution with ferric sulfate.

By the Fo Erhade titration above-mentioned alchlor supported catalyst is carried out chloride content determination, get that chlorinity is 6.51 ω % in the supported catalyst; Survey metallic iron, aluminium content with atomic absorption spectrum, iron content is 0.59 ω %, and load aluminium content is 3.13 ω %.

The oligomerisation of catalysis 1-decene records 1-decene conversion ratio 58.6 ω %, 100 ℃ of kinematic viscosity 6.99mm of oligomer ²/ s.

Embodiment 7

The preparation of load aluminum trichloride catalyst and catalysis 1-decene oligomerisation step condition are with embodiment 3, and difference is that VIII group 4 transition metal salting liquid is immobilized: dipping is 12 hours in the 1.0M nickel nitrate solution.

By the Fo Erhade titration above-mentioned alchlor supported catalyst is carried out chloride content determination, get that chlorinity is 9.00 ω % in the supported catalyst; Survey metallic nickel, aluminium content with atomic absorption spectrum, nickel content is 2.25 ω %, and load aluminium content is 4.38 ω %.The oligomerisation of catalysis 1-decene records 1-decene conversion ratio 55.4 ω %, 100 ℃ of kinematic viscosity 5.25mm of oligomer ²/ s.

Embodiment 8

The preparation of load aluminum trichloride catalyst and catalysis 1-decene oligomerisation step condition are with embodiment 7, and difference is that VIII group 4 transition metal salting liquid is immobilized: transition metal salt solution is the mixture of 1: 1 1.0M nickel nitrate solution of volume ratio and 1.0M copper-bath.

By the Fo Erhade titration above-mentioned alchlor supported catalyst is carried out chloride content determination, get that chlorinity is 8.30 ω % in the supported catalyst; Survey metallic nickel, copper, aluminium content with atomic absorption spectrum, nickel content is 1.15 ω %, and copper content is 1.08 ω %, and load aluminium content is 4.54 ω %.The oligomerisation of catalysis 1-decene records 1-decene conversion ratio 56.0 ω %, 100 ℃ of kinematic viscosity 6.45mm of oligomer ²/ s.

Embodiment 9

Load aluminum trichloride catalyst preparation process condition is with embodiment 3; difference is that aluminum trichloride solution is immobilized: under argon shield; the 10g aluminum trichloride (anhydrous) is made solution in the 100ml carbon tetrachloride; join in the alumina support after 10g activates; under reflux temperature, kept 24 hours; desolventizing with the n-hexane washing, obtains the alchlor supported catalyst after the vacuum drying.

By the Fo Erhade titration above-mentioned alchlor supported catalyst is carried out chloride content determination, get that chlorinity is 8.24 ω % in the supported catalyst; Survey metallic nickel, aluminium content with atomic absorption spectrum, nickel content is 1.75 ω %, and load aluminium content is 3.84 ω %.

The oligomerisation of catalysis 1-decene records 1-decene conversion ratio 58.6 ω %, 40 ℃ of kinematic viscosity 18.94mm of oligomer ²/ s, 100 ℃ of kinematic viscosity 5.97mm ²/ s.

Embodiment 10

The preparation of load aluminum trichloride catalyst and catalysis 1-decene oligomerisation step condition are with embodiment 9, and difference is that aluminum trichloride solution is immobilized: kept 12 hours under the reflux temperature.

By the Fo Erhade titration above-mentioned alchlor supported catalyst is carried out chloride content determination, get that chlorinity is 8.74 ω % in the supported catalyst; Survey metallic nickel, aluminium content with atomic absorption spectrum, nickel content is 2.02 ω %, and load aluminium content is 4.12 ω %.

The oligomerisation of catalysis 1-decene records 1-decene conversion ratio 61.24 ω %, 100 ℃ of kinematic viscosity 5.23mm of oligomer ²/ s.

Embodiment 11

The preparation of load aluminum trichloride catalyst and catalysis 1-decene oligomerisation step condition are with embodiment 9, and difference is that aluminum trichloride solution is immobilized: kept 6 hours under the reflux temperature.

By the Fo Erhade titration above-mentioned alchlor supported catalyst is carried out chloride content determination, get that chlorinity is 8.20 ω % in the supported catalyst; Survey metallic nickel, aluminium content with atomic absorption spectrum, nickel content is 1.85 ω %, and load aluminium content is 3.91 ω %.

The oligomerisation of catalysis 1-decene records 1-decene conversion ratio 57.14 ω %, 100 ℃ of kinematic viscosity 460mm of oligomer ²/ s.

Embodiment 12

The preparation of load aluminum trichloride catalyst and catalysis 1-decene oligomerisation step condition are with embodiment 3, and it is the 1-octene that difference is to urge the oligomerisation monomer.

The catalyzed 1-octylene oligomerisation records 1-octene conversion ratio 67.0 ω %, 100 ℃ of kinematic viscosity 3.12mm of oligomer ²/ s.

Comparative example 1

Spherical gamma-alumina load aluminum trichloride catalyst preparation and catalysis 1-decene oligomerisation step condition are with embodiment 3, and difference is that carrier carried out impregnation process 2 hours with 0.5M hydrochloric acid, did not have the immobilized step of VIII group 4 transition metal salting liquid.

By the Fo Erhade titration above-mentioned alchlor supported catalyst is carried out chloride content determination, get that chlorinity is 6.88 ω % in the supported catalyst.

Products obtained therefrom 1-decene conversion ratio 37.8 ω %, 100 ℃ of kinematic viscosity 2.46mm of oligomer ²/ s.

Comparative example 2

Spherical gamma-alumina load aluminum trichloride catalyst preparation and catalysis 1-decene oligomerisation step condition are with embodiment 3, difference is not carry out carrier acidifying impregnation process and the immobilized step of VIII group 4 transition metal salting liquid, and carrier directly carries out aluminum trichloride solution through 400 ℃ of roastings after 6 hours immobilized.

By the Fo Erhade titration above-mentioned alchlor supported catalyst is carried out chloride content determination, get that chlorinity is 6.93 ω % in the supported catalyst.

Products obtained therefrom 1-decene conversion ratio is 30.30 ω %, 100 ℃ of kinematic viscosity 2.45mm of oligomer ²/ s.

Comparative example 3

Load aluminum trichloride catalyst preparation and catalysis 1-decene oligomerisation step condition be with embodiment 3,, difference is 200 ℃ of supported catalyst sintering temperatures.

By the Fo Erhade titration above-mentioned alchlor supported catalyst is carried out chloride content determination, get that chlorinity is 9.47 ω % in the supported catalyst.

Products obtained therefrom 1-decene conversion ratio 43.0 ω %, 100 ℃ of kinematic viscosity 4.24mm of oligomer ²/ s.

Claims

1. a preparation method of α-olefin oligomerization immobilized catalyst, is characterized in that:

1) Acidizing and impregnating the γ-alumina carrier: the specific conditions are: at room temperature, immerse the γ-alumina carrier in 0.5-2.0M hydrochloric acid, sulfuric acid, nitric acid or their mixture solution for 4-12 hours, and then Vacuum drying at 80-100°C for 2-12 hours;

2) impregnating the acidified γ-alumina support with Group VIII transition metal salt: the specific conditions are: at room temperature, the acidified γ-alumina support is impregnated with 0.5-3.0M Group VIII transition metal iron, cobalt or Soak in nickel sulfate or nitrate solution for 6-12 hours, then vacuum dry at 80-100°C for 2-12 hours; then perform high-temperature roasting at 300-800°C for 6-16 hours;

3) Immobilize aluminum trichloride in solution: add 5-10 g of anhydrous aluminum trichloride to 100 ml of carbon tetrachloride, chloroform or dichloromethane solvent to make a solution, add 10-20 g of activated In the gamma-alumina carrier, keep at reflux temperature for 6 to 24 hours, remove the solvent, wash with n-hexane, and vacuum-dry to obtain gamma-alumina as the carrier, loaded with aluminum trichloride and Group VIII transition metal salt catalyst.

2. the application of the catalyst that the preparation method of a kind of α-olefin oligomerization immobilized catalyst described in claim 1 makes, is characterized in that: be used for 1-decene or 1-octene oligomerization catalyst; 1- The oligomerization reaction of decene or 1-octene uses n-hexane as a solvent, the volume ratio of 1-decene or 1-octene to n-hexane (3:8)~(4:1), at a temperature of 80°C~120°C, the reaction React for 5-6 hours at a pressure of 0.8-1.4 MPa; then stop the reaction, filter the catalyst, distill off the solvent n-hexane under normal pressure, and distill under reduced pressure to remove the unreacted monomer 1-decene or 1-octane and some dimers , to obtain the final oligomer of l-decene or 1-octene.