Process for producing ethylene oligomers

Abstract

The present disclosure relates to a process for producing ethylene oligomers and more particularly, to a process for oligomerizing ethylene by recycling butene, hexene, and octene in an ethylene oligomerization reaction with a catalyst system including a transition metal or transition metal precursor, a ligand with a backbone structure expressed by the following Chemical Formula 1, and a co-catalyst. [Chemical Formula 1] R.sup.1OYOR.sup.2 or R.sup.1OC(O)YC(O)OR.sup.2 Herein, R.sup.1, R.sup.2 are each independently hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl, or substituted heterohydrocarbyl, and Y represents a group connecting O or C(O)O and is hydrocarbyl, substituted hydrocarbyl, hetero hydrocarbyl, or substituted heterohydrocarbyl. According to the oligomerization method of the present disclosure, in the distribution of the produced -olefins, C10-C12 -olefins care highly distributed, the produced -olefins have a remarkably high purity.

Claims

1. A process for producing ethylene oligomers, the process comprising: introducing a catalyst system and ethylene in a reactor; carrying out oligomerization of the ethylene in the reactor to produce a reaction product; separating the ethylene oligomers from the reaction product; and recycling butene, hexene, and octene from the ethylene oligomers back in the oligomerization reaction, wherein the catalyst system comprises a transition metal or transition metal precursor, a ligand with a backbone structure expressed by the following General Formula 1, and a co-catalyst:
R.sup.1OC(O)YC(O)OR.sup.2[General Formula 1] wherein R.sup.1, R.sup.2 are each independently hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl, or substituted heterohydrocarbyl, and Y represents a group connecting C(O)O and is hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl, or substituted heterohydrocarbyl.

2. The process for producing ethylene oligomers of claim 1, wherein the ligand with a backbone structure expressed by General Formula 1 is any one selected from dicarboxylic acid ester compounds represented by the following General Formula 2 to General Formula 6: ##STR00003## wherein R.sup.1 and R.sup.2 are each independently hydrogen or a linear or branched alkyl group having 1 to 20 carbon atoms, a cyclic alkyl group or alkenyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an arylalkyl group or alkylaryl group having 7 to 20 carbon atoms and are combined to form a cycle, and R.sup.3 and R.sup.4 are each independently a linear or branched alkyl group having 1 to 20 carbon atoms, ##STR00004## wherein R.sup.1 and R.sup.2 are identical to or different from each other and represent linear, branched, or cyclic alkyl groups or alkenyl groups having 1 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, or arylalkyl groups or alkylaryl groups having 7 to 20 carbon atoms; and R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are identical to or different from each other and represent hydrogen, linear, branched, or cyclic alkyl groups or alkenyl groups having 1 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, or arylalkyl groups or alkylaryl groups having 7 to 20 carbon atoms.

3. The process for producing ethylene oligomers of claim 2, wherein the dicarboxylic acid ester of General Formula 2 is any one selected from malonate, succinate, glutarate, pivalate, adipate, sebacate, malate, naphthalene dicarboxylate, trimellitate, benzene-1,2,3-tricarboxylate, pyromellitate, and carbonate.

4. The process for producing ethylene oligomers of claim 3, wherein the dicarboxylic acid ester of General Formula 2 is any one selected from diethyl malonate, dibutyl malonate, dimethylsuccinate, diethylsuccinate, dinormalpropyl succinate, diisopropylsuccinate, 1,1-dimethyl-dimethylsuccinate, 1,1-dimethyl-diethylsuccinate, 1,1-dimethyl-dinormalpropylsuccinate, 1,1-dimethyl-diisopropylsuccinate, 1,2-dimethyl-dimethylsuccinate, 1,2-dimethyl-diethylsuccinate, ethyl-dimethylsuccinate, ethyl-diethylsuccinate, ethyl-dinormalpropylsuccinate, ethyl-diisopropylsuccinate, 1,1-diethyl-dimethylsuccinate, 1,1-diethyl-diethylsuccinate, 1,1-diethyl-dimethylsuccinate, 1,2-diethyl-dimethylsuccinate, 1,2-diethyl-diethylsuccinate, 1,2-diethyl-dinormalpropylsuccinate, 1,2-diethyl-diisopropylsuccinate, normalpropyl-dimethylsuccinate, normalpropyl-diethylsuccinate, normalpropyl-dinormalpropylsuccinate, normalpropyl-diisopropylsuccinate, isopropyl-dimethylsuccinate, isopropyl-diethylsuccinate, isopropyl-dinormalpropylsuccinate, isopropyl-diisopropylsuccinate, 1,2-diisopropyl-dimethylsuccinate, 1,2-diisopropyl-diethylsuccinate, 1,2-diisopropyl-dinormalpropylsuccinate, 1,2-diisopropyl-diisopropylsuccinate, normalbutyl-dimethylsuccinate, normalbutyl-diethylsuccinate, normalbutyl-dinormalpropylsuccinate, normalbutyl-diisopropylsuccinate, isobutyl-dimethyl succinate, isobutyl-diethylsuccinate, isobutyl-dinormalpropylsuccinate, isobutyl-diisopropylsuccinate, 1,2-dinormalbutyl-dimethylsuccinate, 1,2-dinormalbutyl-diethylsuccinate, 1,2-dinormalbutyl-dinormalpropylsuccinate, 1,2-dinormalbutyl-diisopropylsuccinate, 1,2-dinormalbutyl-dimethylsuccinate, 1,2-diisobutyl-dimethylsuccinate, 1,2-diisobutyl-diethylsuccinate, 1,2-diisobutyl-dinormalpropylsuccinate, 1,2-diisobutyl-diisopropylsuccinate, diethyl adipate, dibutyl adipate, diethyl sebacate, dibutyl sebacate, diethyl malate, di-n-butyl malate, diethyl naphthalene dicarboxylate, dibutyl naphthalene dicarboxylate, triethyl trimellitate, tributyl trimellitate, triethyl benzene-1,2,3-tricarboxylate, tributyl benzene-1,2,3-tricarboxylate, tetraethyl pyromellitate, and tetrabutyl pyromellitate.

5. The process for producing ethylene oligomers of claim 1, wherein the transition metal or transition metal precursor is chromium or a chromium precursor.

6. The process for producing ethylene oligomers of claim 5, wherein the chromium or chromium precursor is selected from the group consisting of chromium(III)acetylacetonate, chromium trichloride tristetrahydrofuran, and chromium(III)2-ethylhexanoate.

7. The process for producing ethylene oligomers of claim 1, wherein the co-catalyst includes one or more selected from methylaluminoxane (MAO), ethylaluminoxane (EAO), and isobutylaluminoxane (IBAO).

8. The process for producing ethylene oligomers of claim 1, wherein the co-catalyst is a combination of trialkylaluminum and the following borate or boron compound: dimethylphenylammoniumtetra(phenyl)borate, trityltetra(phenyl)borate, triphenylboron, dimethylphenylammoniumtetra(pentafluorophenyl)borate, sodiumtetrakis[(bis-3,5-trifluoromethyl)phenyl]borate, H+(0Et.sub.2)2[(bis-3,5-trifluoromethyl)phenyl]borate, trityltetra(pentafluorophenyl)borate and tris(pentafluorophenyl)boron, trimethylammonium tetraphenylborate, triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, tributylammonium tetraphenylborate, trimethylammonium tetrakis(pentafluorophenyl)borate, triethylammonium tetrakis(pentafluorophenyl)borate, tripropylammonium tetrakis(pentafluorophenyl)borate, tributylammonium tetrakis(pentafluorophenyl)borate, anilinium tetraphenylborate, anilinium tetrakis(pentafluorophenyl)borate, pyridinium tetraphenylborate, pyridiniumtetrakis(pentafluorophenyl)borate, ferrocenium tetrakis(pentafluorophenyl)borate, silver tetraphenylborate, silver tetrakis(pentafluorophenyl)borate, tris(pentafluorophenyl)borane, tris(2,3,5,6-tetrafluorophenyl)borane, tris(2,3,4,5-tetraphenylphenyl)borane, and tris(3,4,5-trifluorophenyl)borane.

9. The process for producing ethylene oligomers of claim 2, wherein the transition metal or transition metal precursor is chromium or a chromium precursor.

10. The process for producing ethylene oligomers of claim 2, wherein the co-catalyst includes one or more selected from methylaluminoxane (MAO), ethylaluminoxane (EAO), and isobutylaluminoxane (IBAO).

11. The process for producing ethylene oligomers of claim 2, wherein the co-catalyst is a combination of trialkylaluminum and the following borate or boron compound: dimethylphenylammoniumtetra(phenyl)borate, trityltetra(phenyl)borate, triphenylboron, dimethylphenylammoniumtetra(pentafluorophenyl)borate, sodiumtetrakis[(bis-3,5-trifluoromethyl)phenyl]borate, H.sup.+(0Et.sub.2)2[(bis-3,5-trifluoromethyl)phenyl]borate, trityltetra(pentafluorophenyl)borate and tris(pentafluorophenyl)boron, trimethylammonium tetraphenylborate, triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, tributylammonium tetraphenylborate, trimethylammonium tetrakis(pentafluorophenyl)borate, triethylammonium tetrakis(pentafluorophenyl)borate, tripropylammonium tetrakis(pentafluorophenyl)borate, tributylammonium tetrakis(pentafluorophenyl)borate, anilinium tetraphenylborate, anilinium tetrakis(pentafluorophenyl)borate, pyridinium tetraphenylborate, pyridiniumtetrakis(pentafluorophenyl)borate, ferrocenium tetrakis(pentafluorophenyl)borate, silver tetraphenylborate, silver tetrakis(pentafluorophenyl)borate, tris(pentafluorophenyl)borane, tris(2,3,5,6-tetrafluorophenyl)borane, tris(2,3,4,5-tetraphenylphenyl)borane, and tris(3,4,5-trifluorophenyl)borane.

Description

DRAWING

(1) The drawing described herein is for illustrative purposes only of selected embodiments and not all possible implentations, and is not intended to limit the scope of the present disclosure.

(2) FIG. 1 is a diagram illustrating an ethylene continuous process for a process for producing ethylene oligomers of the present disclosure.

DETAILED DESCRIPTION

(3) Example embodiments will now be described more fully with reference to the accompanying drawing.

(4) In the following detailed description, reference is made to the accompanying drawing, which forms a part hereof. The illustrative embodiments described in the detailed description, drawing, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here.

(5) Hereinafter, examples of the present disclosure will be described in more detail. However, the following examples are provided to aid in the understanding of the present disclosure, but shall not be construed as limiting the scope of the present disclosure, and various modifications and changes can be made from the following examples without departing from the spirit of the present disclosure.

(6) [Materials and Analysis Instrument]

(7) The synthesis reactions described below were performed under an inert atmosphere such as nitrogen or argon using Standard Schlenk and Glove Box techniques.

(8) Solvents for synthesis such as tetrahydrofuran (THF), normalhexane (n-Hexane), normalpentane (n-Pentane), diethylether and methylene chloride (CH.sub.2Cl.sub.2) were passed through an activated alumina column to remove moisture and then used as being preserved on an activated molecular sieve.

(9) Gas chromatography (GC) analysis was performed using an Agilent technologies 7890A GC system under the conditions including a carrier gas of N.sub.2, a carrier gas flow of 2.0 mL/min, a split ratio of 20/1, an initial oven temperature of 50 C., an initial time of 2 min, a ramp of 10 C./min, and a final temperature of 280 C. A column used herein was an HP-5, and ethanol or nonane was quantified to be used as internal standard.

EXAMPLES

(10) Diethyl-2,3-diisobutylsuccinate (WO 00/63261) was synthesized by the processes disclosed in the corresponding documents. Methyl aluminoxane, a 10% w/w solution in toluene, was purchased from Albemarle and the other reagents such as triethyl aluminum were purchased from Aldrich chemical company unless otherwise noted.

Catalyst Synthesis Example 1

(11) CrCl.sub.3(THF).sub.3 (0.02 mmol) was introduced into a Schlenk flask, and 40 ml of methylenechloride was added thereto and stirred. Then, diethyl-2,3-diisobutyl-succinate (0.02 mmol) was slowly added thereto, and the solution was stirred for 4 hours. Then, the solvent was removed under reduced pressure and the resultant solid was suspended in toluene and then used as a stock solution.

Catalyst Synthesis Comparative Example 1

(12) Zirconium tetrachloride (ZrCl.sub.4) (2.5 mmol) was introduced into a Schlenk flask, and 50 ml of toluene was added thereto with stirring. A triethyl aluminum solution (3.9 mmol) was added thereto for 30 minutes with stirring. Then, an ethylaluminum sesquichloride solution (13.6 mmol) was further added thereto for 30 minutes. Then, the temperature was increased to 70 C. and a reaction was carried out for 1 hour. Then, the temperature was lowered to room temperature, and the entire solution was used as a catalyst stock solution.

Example 1

(13) A 300-ml stainless steel reactor was washed with nitrogen in a vacuum and then 50 ml of toluene was added thereto, and 10.0 mmol-Al MAO was added thereto. Then, the temperature was increased to 65 C. A 0.01 mmol toluene solution was taken out of the catalyst stock solution prepared in Catalyst Synthesis Example 1 and then introduced into the reactor. 50 ml of toluene was introduced into a pressure reactor and ethylene was fed into the pressure reactor under a pressure of 32 bar and then stirred at a stirring speed of 600 rpm. After 30 minutes, the supply of ethylene into the reactor was stopped and the stirring was stopped to stop the reaction. The reactor was cooled to lower than 10 C. After the unreacted ethylene within the reactor was discharged, ethanol mixed with 10 vol % of hydrochloric acid was added to the liquid present in the reactor. A small amount of an organic layer sample was passed through anhydrous magnesium sulfate and dried and then analyzed using GC-FID. The remaining organic layer was filtered to separate a solid wax/polymer product therefrom. The organic layer was separated into C6 (hexene) and C8 (octene) via distillation. After the solid product was dried in an oven at a temperature of 100 C. overnight, a polymer was obtained and the weight of the polymer was checked. The oligomer distribution in the reaction mixture obtained via GC analysis is given in Table 1.

Example 2

(14) The process of Example 1 was performed in the same manner except that 14 ml of 1-hexene was additionally used after 50 ml of toluene was introduced into the reactor, and the result of GC analysis and the oligomer distribution are given in Table 1. In the result of GC analysis, the unreacted part of the added 1-hexene was excluded from the calculation of the oligomer distribution.

Example 3

(15) The process of Example 1 was performed in the same manner except that 35 ml of 1-hexene was additionally used after 50 ml of toluene was introduced into the reactor, and the result of GC analysis and the oligomer distribution are given in Table 1. In the result of GC analysis, the unreacted part of the added 1-hexene was excluded from the calculation of the oligomer distribution.

Example 4

(16) The process of Example 1 was performed in the same manner except that 70 ml of 1-hexene was additionally used after 50 ml of toluene was introduced into the reactor, and the result of GC analysis and the oligomer distribution are given in Table 1. In the result of GC analysis, the unreacted part of the added 1-hexene was excluded from the calculation of the oligomer distribution.

Example 5

(17) The process of Example 1 was performed in the same manner except that 15 ml of 1-octene was additionally used after 50 ml of toluene was introduced into the reactor, and the result of GC analysis and the oligomer distribution are given in Table 1. In the result of GC analysis, the unreacted part of the added 1-octene was excluded from the calculation of the oligomer distribution.

Example 6

(18) The process of Example 1 was performed in the same manner except that 25 ml of 1-octene was additionally used after 50 ml of toluene was introduced into the reactor, and the result of GC analysis and the oligomer distribution are given in Table 1. In the result of GC analysis, the unreacted part of the added 1-octene was excluded from the calculation of the oligomer distribution.

Example 7

(19) The process of Example 1 was performed in the same manner except that 80 ml of 1-octene was additionally used after 50 ml of toluene was introduced into the reactor, and the result of GC analysis and the oligomer distribution are given in Table 1. In the result of GC analysis, the unreacted part of the added 1-octene was excluded from the calculation of the oligomer distribution.

Example 8

(20) The process of Example 1 was performed in the same manner except that 35 ml of 1-hexene and 25 ml of 1-octene were additionally used after 50 ml of toluene was introduced into the reactor, and the result of GC analysis and the oligomer distribution are given in Table 1. In the result of GC analysis, the unreacted part of the added 1-hexene and 1-octene was excluded from the calculation of the oligomer distribution.

Example 9

(21) The process of Example 1 was performed in the same manner except that 35 ml of 1-hexene and 25 ml of 1-octene were additionally used after 50 ml of toluene was introduced into the reactor and oligomerization was carried out at 25 C., and the result of GC analysis and the oligomer distribution are given in Table 1. In the result of GC analysis, the unreacted part of the added 1-hexene and 1-octene was excluded from the calculation of the oligomer distribution.

Comparative Example 1

(22) A 300-ml stainless steel reactor was washed with nitrogen in a vacuum and then 50 ml of toluene was added thereto, and 10.0 mmol-Al MAO was added thereto. Then, the temperature was increased to 65 C.

(23) A 0.3 mmol toluene solution was taken out of the catalyst stock solution prepared in Catalyst Synthesis Example 1 and then introduced into the reactor. Ethylene was fed into a pressure reactor under a pressure of 32 bar and then stirred at a stirring speed of 600 rpm. After 30 minutes, the supply of ethylene into the reactor was stopped and the stirring was stopped to stop the reaction. The reactor was cooled to lower than 10 C. After the unreacted ethylene within the reactor was discharged, ethanol mixed with 10 vol % of hydrochloric acid was added to the liquid present in the reactor. A small amount of an organic layer sample was passed through anhydrous magnesium sulfate and dried and then analyzed using GC-FID. The remaining organic layer was filtered to separate a solid wax/polymer product therefrom. The organic layer was separated into C6 (hexene) and C8 (octene) via distillation. After the solid product was dried in an oven at a temperature of 100 C. overnight, a polymer was obtained and the weight of the polymer was checked. The oligomer distribution in the reaction mixture obtained via GC analysis is given in Table 1.

Comparative Example 2

(24) The process of Example 1 was performed in the same manner except that 15 ml of 1-octene was additionally used after 50 ml of toluene was introduced into the reactor according to Comparative Example 1, and the result of GC analysis and the oligomer distribution are given in Table 1. In the result of GC analysis, the unreacted part of the added 1-octene was excluded from the calculation of the oligomer distribution.

Comparative Example 3

(25) The process of Example 1 was performed in the same manner except that 25 ml of 1-octene was additionally used after 50 ml of toluene was introduced into the reactor according to Comparative Example 1. In the result of GC analysis, the unreacted part of the added 1-octene was excluded from the calculation of the oligomer distribution.

Comparative Example 4

(26) The process of Example 1 was performed in the same manner except that 80 ml of 1-octene was additionally used after 50 ml of toluene was introduced into the reactor according to Comparative Example 1. In the result of GC analysis, the unreacted part of the added 1-octene was excluded from the calculation of the oligomer distribution.

Comparative Example 5

(27) The process of Example 1 was performed in the same manner except that 35 ml of 1-hexene and 25 ml of 1-octene were additionally used after 50 ml of toluene was introduced into the reactor according to Comparative Example 1. In the result of GC analysis, the unreacted part of the added 1-hexene and 1-octene was excluded from the calculation of the oligomer distribution.

(28) TABLE-US-00001 TABLE 1 Result of oligomerization Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Activity (Kg- 62.5 229 213 176 174 146 140 117 lefins/g- [M]/hr) Oligomer C.sub.6 18.3 11.8 5.8 5.4 6.4 6.4 7.1 7.6 Distribution (wt %) and C.sub.8 221. 18.8 17.6 16.2 13.3 12.8 10.9 12.2 purity (wt %) C.sub.10- 28.1 32.4 35.2 36.5 39.7 39 41.7 50.7 C.sub.12 (wt %) C.sub.12+ 24.4 30.7 34.7 36.3 34.8 35.8 35.3 22.3 (wt %) C.sub.10 94.2 93.3 92.8 95.4 95.2 93.2 93.6 Purity (1-C.sub.10/ C.sub.10) (wt %) Comparative Comparative Comparative Comparative Comparative Example 9 Example. 1 Example. 2 Example. 3 Example. 4 Example. 5 Activity (Kg- 202 6.7 23 23 21 23 lefins/g- [M]/hr) Oligomer C.sub.6 5.8 20.8 18.5 20.1 22.3 7.8 Distribution (wt %) and C.sub.8 12.3 10.2 5.8 5.8 4.8 4.8 purity (wt %) C.sub.10- 57.8 17.2 29.1 27.3 23.7 38.4 C.sub.12 (wt %) C.sub.12+ 18.3 18.4 20.2 21.8 22.6 26.6 (wt %) C.sub.10 96.5 71.1 74.5 78.1 66.7 Purity (1-C.sub.10/ C.sub.10) (wt %)

(29) As listed in Table 1, it can be seen from the results of oligomerization according to Example 2 to Example 9 of the present disclosure carried out by recycling C6 olefin and C.sub.8 olefin among olefins prepared in Example 1 that in the oligomer distribution, C.sub.10 and C.sub.12 olefins are highly distributed via the novel oligomerization method of the present disclosure as compared with Comparative Examples 2 to 5. As exhibited in Example 2 to Example 9, the olefins have a very high purity.

(30) From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

EXPLANATION OF REFERENCE NUMERALS

(31) 1: Catalyst 2: Solvent 3: Reactor 4: Catalyst deactivation/Gas-liquid separator 5: C.sub.2 separator 6: Distiller 7: Introduce C.sub.2 8: Introduce C.sub.6/C.sub.8 9: C.sub.10+ olefin

(32) The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.