Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
Z004494
-- 1 --
FIELD OF THE INVENTION
The present invention provides a multistep
process for the conversion of the olefinic com-
ponents of thermally cracked petroleum residua to
novel paraffin products useful as synthetic lubri-
cants. The preferred feed is produced by the high
temperature thermal cracking of vacuum resids,
particularly by Fluid-coking and Flexicoking. The
distillate products of these processes contain high
percentages of the desired linear olefin reactants.
Due to the presence of relatively high amounts of
sulfur these distillates are below liguid fuel
value.
one aspect of the invention is the des-
cription of the types of compounds produced by the
thermal cracking of petroleum resids. The desired
l-n-olefin and linear internal olefin components of
light gas oil distillates, derived by cracking
vacuum resids in fluidized bed processes, were
particularly investigated. They were characterized
by a combination of high resolution capillary gas
chromatography (GC~ mass spectrometry
(MS) and nuclear magnetic resonance spectroscopy
(NMR). The aromatic components and sulfur compounds
present in craaked distillates were also analyzed
because they potentially interfere with the desired
oligomerization of the olefin components.
200~4~
- 2 -
Another aspect of the invention is the
separation of the desired linear olefin components
of cracked petroleum distillates. The separation
via urea adduction and by crystallization of mix-
tures of l-n-olefinS and n-paraffins is particularly
taught. Appropriate carbon range fractions of such
mixtures can b~ used a~ a feed for oligomerization
reactions without prior paraffin separation.
Extraction of the coker digtillate feed can be used
for the removal of the aromatic components, includ-
ing most of the sul~ur compounds. Membrane separa-
tion can result in an aliphatic and an aromatic
hydrocarbon rich fraction.
A key aspect of the invention is the
oligomerization of the linear ole~in mixtures
derived from cracked petroleum distillates to
provide intermQdiates for synthetic lubricants. The
dimers, trimers and tetramers derived from C10 to
C17 1-n-olefins are particularly described.
The final step in the production of the
isoparaffin lubricants via the process is the
hydrogenation of the polyolefin intermediates in the
presence of known hydrogenation catalysts. ~he
eli~ination of the unsaturation of polyolefins is a
necessary step in producing synthetic lubricants of
outstanding stability.
A~id- ~rom th- multlstep process, the
other ma~or aspect o~ the pre--nt invention relates
to the unique structure and lubrlcant properties of
the products. In this respect branching and mole-
cular weight of the isoparaf~in products and their
2(~ 49~
viscosity and low temperature properties are parti-
cularly discussed.
BACKGROUND OF THE INVENTION
The synthesis, properties and applications
of lubricants are summarized in a monograph entitled
"Lubricants and Related Products" by Dieter Klamann.
This book, published by Verlag Chemie, Weinheim, W.
Germany in 1984 has a chapter (pages 96 to 106)
which specifically discusses synthetic hydrocarbon
lubricants, including those derived from olefins.
The preparation of synthetic lubricants
via olefin oligomerization in general is well known
in the prior art. J.A. Brennan of Mobil published
an early review of the literature in the journal,
Ind. Eng. ~hem., Prod. Res. Dev. Vol. 19, pages 2-6
in 1980 and the references of this article. Brennan
particularly investigated the oligomerization of
even carbon number ~-olefins from ethylene. His
work was aimed at getting isoparaffins of wide
temperature range fluidity via the hydrogenation of
the oligomer intermediates. Based on this work, he
concluded that decene trimers obtained via BF3
catalyzed oligomerization provide superior lubricant
fluids on hydrogenation. Such trimers are a main
component of the commercial Mobil 1 synthetic
lubricant.
20()4494
While l-decene based synthetic hydrocarbon
lubricants have excellent quality, their economics
of manufacture are unfavorable. 1-Decene is only
one of the products of ethylene oligomerization.
Therefore, its availability is limited and its price
is very high. There is a great need for other
synthetic hydrocarbon lubricants of greater avail-
ability and lesser cost.
The above referred Brennan publication and
an article by Onopchenko, Cupples and Kresge in Ind.
Eng. Chem., Prod. Res. Dev. Vol. 2, pages 182-191 in
1983 discussed the structures of various potential
hydrogenated polyolefin lubricant candidates and
correlated them with their low temperature behavior
characterized by solidification temperatures or pour
points and wide temperature behavior indicated by
their viscosity indices. They found that iso-
paraffins having short n-alkyl segments had out-
standing low temperature behavior, but poor vis-
cosity characteristics. In contrast, long n-alkyl
segments assure desirable viscosity but lead to poor
low temperature behavior. The design of lubricants
having balanced properties apparently calls for an
innovative compromise in molecular design. It
appears that isoparaffins in the C2s to C60 carbon
range per molecule are qood lubricant candidates, if
2004~94
- 5 -
they have 1 to 3 alkyl side chains of medium chain
length on the n-alkane carbon skeleton as close to
the center of the molecule as possible.
One of the prior art approaches to iso-
paraffins of improved economics is described by
Petrillo et. al. in U.S. patent 4,167,534. Accord-
ing to this patent, the feed for oligomerization is
C11 to C14 mixture of n-olefins having double bonds
statistically distributed along the entire chain.
Such olefins are obtained via the dehydrogenation of
the corresponding paraffins as prepared by the
ISOSIV process and are utilized as the feed~
Oligomerization is carried out in the presence of a
Friedel Crafts catalyst, preferably AlC13. The
hydrogenated oligomers have an excellent low
temperature behavior, i.e. pour points of -50~C or
lower and kinematic viscosities at 40C in the range
of about 30 to 40 centistokes.
Another approach to synthetic lubricants
is disclosed by L. Heckelsberg in U.S. Patent
4,317,948 assigned to Phillips Petroleum Co. In the
first step, Heckelsberg produces an internal olefin,
preferably via metathesis of an ~-olefin. In the
second step, the internal olefin is codimerized with
an ~-olefin. For example, l-dodecene, is converted
to a ll-docosene which is then isolated and codi-
merized with l-dodecene to provide C34 isoolefins:
200449~
- 6 -
Cl oH2 1CH--CH2 CloH2 lCH~CHC 1 oH2 1
CloH2 1CH--CH2
c34H68 ~
U.S. Patent 4,319.064 by Heckelsberg et. al. dis-
closes the dimerization of BF3 based catalyqts of
internal olefin dimer fractions obtained via the
metathesis of Cg, Clo and C12 ~-olefins. Another
method based on the metathQ~is of ~-olefin~ i8
disclosed in U.S. patent 4,300,006 by W.T. Nelson,
also assigned to Phillips. This patent describes
the boron trifluoride ca~alyzed cod~merization
without prior separation of the components of a
~-olefin metathesis reaction mixture~. The products
o~ both the HecXel~berg and the Nelson patents have
pour points in the range of about -32 to -54-C and
40-C viscosities oY 100 to 133 cst.
A large number of patents have issued
covering the oligomerization of linear olefins in
the C6 to C~s range to lubricants. Most of them
employ even carbon ~-olefins as a feed. However, a
few patents disclo~e the u e of cracXed wax olefins.
U.S~ Patent 1,955,200 by Sullivan, Jr. and
Voorhe~-, aosigned to Standard Oil Co. of Indiana,
disclose- the ~ynthesi~ o~ a stable, high VI lube
oil via wax cracklng followed by polymerlzation in
the presence o~ AlC13 as a catalyst.
200'~494
- 7 -
U.S. Patent 3,883,417, by C. Woo and J.A.
Bichard, assigned to Exxon, degcribes a two stage
procees for the production of lube oils by the
thermal polymerizatin of the ole~in components of
steam cracked paraffin waxes and ga5 oils. In the
first stage, the more reactive components such as
diolefins are polymerized. A di9tillate containing
the less reactive ~-olefin components is separated
from the reaction mixture and converted to lubri-
cants of high viscosity index.
U.S. Patent 3,156,736 assigned to Shell
also utilized cracked wax ol~fin~ for producing
lubricants. In the Shell process Cg to C17 cracked
wax olefins are fir t separated by urea clathration.
Then they are purified by percolation over silica
gel. The pure 012fins ar~ polymerized using an
aluminum trialkyl - titanium tetrachlorid2 catalyst
system. The C30 and higher distillate product
fraction is hydrogenated to provide the lubricant
product. Another U.S. Patent to Shell, No.
2,051,612 describes a process for the preparation of
a suitable olefin feed for lube oil manufacture.
According to this patent a paraffinous oil provides
the desired olefins in a two stage cracking process.
Variou~ acid catalysts and Ziegler-Natta
type catalyst systems as well as thermal processes
were utilized to oligomerize higher olefins to
lubricant intermediates. Boron tri~luoride based
catalyst systQms w~ro mo-t oxt-n-iv-ly inv-stigated.
U.S. Patent 2,816,944 by Mue~-ig and Lippincott to
Exxon disclosad th- use of a BF3-H3P04 system for
the oligom~rization of C6 to C2s olefins. U.S.
20~494
Patent 3,382,291, by Brennan to Mobil describes a
proCQss for the oligomerisation of Cs to C20
~-olefins, preferably l-decene in the presence of
BF3 plus a 1:1 BF3 complex of water, alcohol, acids,
ethers, esters, aldehydes, and Xetones. Another
Mobil patent, i.e. U.S. Patent 3,769,363, specifi-
cally claims ths oligomerization of C6-cl2 olefins
with BF3 pentanoic acid complexes. In U.S. Patent
4,213,001, by Madgavkar et. al. as~igned to Gulf,
the oliqomerization of C6 to C12 u-olefins in the
prQsQnce of BF3 treated adsorbQnt silica is claimed.
U.S. Patent 4,218,330, by Shubkin to Ethyl Corp.
specifically disclo~es th~ dimerization f C12 to
Clg ~-olefins in the presence of boron trifluoride
hydrate. A similar proces using a
perfluorosulfonic acid re~in Nafion alone or com-
plexed with BF3 i~ disclosed in U.S. Patents
4,367,352 and 4,400,565, a~signed to Texaco. For
the oligomerization of linear olefins containing
major amounts of le~s reactive internal isomers U.S.
Patent 4,420,646, by Darden, Walts and Marquis of
Texaco, discloses the use of a promoted BF3 catalyst
at elevated temperature. Finally, U.S. Patent
4,417,082, also from Texaco, describes the
cooligomerization of C3-Cs and Cg-Clg ~-olefins with
a similar catalyst systQm at close to ambient
temp~rature.
A~ indicated abov- the linear olefin feeds
for lubricant synthesis o~ the prior art were mostly
derived via ethylene polymerization. These ~eeds
did not require the application of olefin separation
processe~. The only relativ~ly complex feeds
employed were cracked distillates. These contained
Z004494
g
a mixture of mostly linear olefins but no aromaticS
and sulfur compoundc. As it will be discussed the
linear olefin and paraffin components of cracked wax
were separated via urea adduction to produce feeds
for synthetic lubricants. Urea adduction is also
applicable to the thermally cracked, residua derived
feeds of the present process.
The urea adduction method for the separa-
tion of straight chain hydrocarbons and mono-
substltutad derivativeg wa~ discovered by Bengen in
Ger~any during World War II (see German Patent
869,070). Thi8 method wa~ commercially developed,
primarily for the dewaxing of min~ral oil fractions,
i.e. the separation o~ n-para~fins ~rom hydrocarbon
mixtures of aliphatic character. Thi development
was reviewed by Alfred Hoppe of Edeleanu Gmbh, in
Chapter 4, pages 192 to 234 of Volume 8 of a series
of monographs on "Advances in Petroleum Chemistry
and Refining" edited by J.J. McXetta Jr., and
published by Interscience Publishers of J. Wiley &
Sons, New York, 1964. The urea adducts of straight
chain paraffin~ and olefins which are of special
petrochemical interest were described by Schlenk,
Jr. in Fortschritte de Chemischen Forschung, Volume
2, pag~ 92 in (1951), by E. Terres and S. Nath sur
in ~rennsto~f-ChemiQ, Volume 38, pages 330 to 343 in
1957 andby W.G. Domagk and K.A. Kobe in Petroleum
Refin~r, Volumo 34, No. 4, page~ 128-133 in 1955.
The urea adduction method was employed for
the separation of u-olefins as well as n-paraffins.
L.C. Fetterly discus~ed the separation o~ ~-olefin -
n-paraf~in mixtures via urea adduc~ion from cracked
2004494
- 10 --
wax, thermally cracked gas oil and naphtha in
Petroleum Refiner, No. 4, pages 128-133 in 1955.
Such separations wer~ disclosed in detail by Garner
et. al. in U.S. patent 2,528,677 as~igned to Shell,
by Woodbury in U-S- patent 2,642,421 assigned to
SoconY-vacuu~ Oil and by Goldsbrough of Shell at the
19~5 World Petroleum Congres8, Rome, in Section
III/B, Paper 4. Reference to the recovery of
straight chain olefins from cracked 9tOcks via urea
adduction is also made by Bailey et. al. in Ind.
Eng. Chem., Vol. 43, pages 2125-2129 in 1951. Also,
German Patent 3,436,289-A, as~igned to Council of
Scientific and Industrial Research in New Delhi,
discloses the separation via urea adduction of the
~-olefin plus n-paraffin components of coker dis-
tillates derived via cracking crude oil fractions.
The patent also states that the separated olefins
are useful among others in the production o~ syn-
thetic lubricants. However, the coker distillates
employed WerQ apparently o~ low sul~ur content. The
patent states that sulfur compounds inhibit urea
adduct formation and thus teaches away from the
present invention.
Urea adduction was employed commercially
for the separation of n-paraffins in dewaxing.
Several processes were developed on a pilot plant
scale. In Petroleum Re~iner, Volume 36, No. 7,
pag-s 147-152 in 1957, Fetterly reviewed the
commercial urea adduction units. Most of the
detail~ are provided in the previously cited Hoppe
review. The basic featura~ of these proces~es are
discussed in the following since they are applicable
20044~4
-- 11 --
to the coker distillate feed~ of the present pro-
cess.
Standard Oil Co. (Indiana) operated a
dewaxing unit for the production of lubricating oil.
The chemical basi~ of thi9 unit has been described
by zimmerschied and coworkers in Ind. Eng. Chem.,
Vol. 42, pages 1300-1396 in 1950. This publication
and Fetterly'9 review point out that petroleum
fractions usually fail to form adducts in the
absence of an activator due to the presence of
inhibitors, e.g. ~ulfur compounds etc.. In the
Indiana process, probably methanol wa~ used as an
activator solvent.
Deutsche Erdoel produced low-pour diesel
oil spindle oil via urea adduction as described by
Hoppe in Erdoel und Kohle, Vol. II, pages 618 to 621
in 1958. The process employed was designed by
Edeleanu and employed an aqueou~ reactant solution.
A variant of the Edeleanu process using an aqueous
isopropanol solution o~ urea was developed in Russia
and has been de~cribed by J. Bathory in
Chem.-Anlagen Verfahren, No. 3, pages 43 to 46 in
lg72 .
A process first employed by Sonneborn and
Son~ to produc- white oil employed a crystalline
urea reactant. Thi~ typa of a proces- was more
rocently al~o developed by Nippon Mining and Chiyoda
Chem. Eng. and Con~tr. Co.. Under the name Nurex,
the process was designed for producing a n-paraffin
feed for single protein production. The Nurex
proce3~ was de~cribed in Bull. o~ the Japan Petr.
--` 2(~0449~
- 12 -
Inst., Vol 8, June 7-12 issue (1966), the oil and
Gas J., Vol. 70, No- 4, page8 141, 142 in 1972. A
detailed comparison of the Nurex process with the
Edeleneau proces~ was made in the previously refer-
red journal article by Bathory.
Shell Oil Co. developed a process appli-
cable for the separation of the ~-olefin and n-par-
affin components of cracked wax which wag described
by the earlier quoted Bailey et. al., paper in Ind.
Eng. Chem., a paper in the Proceedings of the 2nd
World Petr. Congr., Hague, Sect. III, pages 161-171
also by Bailey et. al. and another paper by
Goldsbrough which was also roferenced earlier. This
process employs both an organic solvQnt, methyl
i-butyl ketone, and water and obtains the urea
adducts by phase separation rather than filtration.
Societe Francais des Petroles also developed a
process based on the sa~e phase separation princi-
ple.
Finally, a separation process using urea
in partition chromatography was also disclosed in
U.S. Patent 2,912,426 assigned to Gulf. This
process wa~ successfully employed as an analytical
technique for the determination of the major
~-olefin and n-paraffin co~ponents of coal tar pitch
(See Karr and Comberiat~, J. Chromatog., Vol. 18,
No. 2, pages 394-397, 1965).
The straight chain hydrocarbon components
o~ distillate by-product~ o~ the thermal cracking of
petroleum residua, with ~up~rhoatad steam to produce
pitch to replace coking coal, were separated by the
Z00449~
- 13 -
urea adduction proceg~ for analytical studies. This
was reported by Ohnuma et- al- in J- Japan Petrol.
Inst., Vol. 21, pages 28-34 in 1978- From a light
oil fraction of 49% oil content up to 25~ yields of
linear hydrocarbons were obtained. Gas chroma-
tography showed that these consisted mostly of
n-paraf~ins (about 70%) and l-n-olefins (20%). The
minor components were l-methylparaffins and internal
n-olefins.
European Patent Applicatlon 164,229 by
Atsushl et. al. assigned to Nippon Petrochemicals
Company disclosed a method of upgrading to paraffins
thermally cracked dlstillat~ products derived from
petrolaum residua. Acccording to this method, the
olefin components of the distillate are reacted with
the aromatic components to produce alXylaromatic
compounds in the presence o~ an acid catalyst in the
first step. The unreacted, paraffin rich co~ponents
of the feed are then separated by distillation from
the reaction mixture in the second step. The
n-paraffins could then be isolated via urea
adduction or by molecular sieve.
Aboul-Gheit, Moustafa and Habib reported,
(in Erdoel und Kohle-Erdgas, Vol. 36, page 462 to
465 in 1985), the i~olatlon in 30% yield of a linear
hydrocarbon mixture consisting 35.6~ n-olefin~ and
64.4% parArrins ~rom a Cll to C14 coker dl~tillate
rractlon containing 43.0% ol~rlns and 29.1~ satu-
rates. Th-y utillzed the product to prepare a
linear alkylbenzene detergent intermediate by the
alkylation of benzene in the presence o a sili-
cotungstic acid catalyst. However, they neither
200~494
- 14 -
disclosed nor suggested the us~ o~ the olefin
components of the products for the synthesis of
lubricant~.
An alternative m2thod of separating the
~-olefin and n-paraffin components of coker dis-
tillate~ i~ crystallization. No positive teaching
could be found in the literature on the direct
separation of n-paraffins plus l-n olefins by
crystallization from any feed. U.S. Patent
3,691,246 by L.C. Parker, T.A. Cooper and J.L.
Meadows described the selective crystallization of
n-paraffins from methylethyl ketone solutions of
sharp distillate fractions o~ cracked wax consisting
of n-paraffins and n-olefin~. Similarly, U.S.
Patent 3,767,724 by Tan Hok Gouw di~closed the
selective crystallization of paraffins from C02
solutions of olefin-paraffin mixtures. A journal
publication by Von Hor~t Gunder~ann, Josef Weiland
and Bernd Speckelsen ~Erdoel and Kohle-Erdgas, Vol
24, No. 11, pages 696 to 701, (1971)] described the
crystallization of C16 ~ C20 n-olefin plus n-paraf-
fin mixtures from methylnaphthalene. The formation
of n-paraffin cry~tals was reported. The authors
concluded that for the cry~tallization of n-olefins
always significantly lower temperatures are required
than for that of the corresponding n-paraffins.
Thua, thio paper al~o taught away from the cocrys-
tallization of thesQ components.
There i9 much literature on the extraction
o~ various petroleu~ distillateJ, particularly for
the production o~ aromatic hydrocarbon extracts.
However, there i~ no specific in~ormation on the
200a~49~
- 15 -
extraction o~ co~er distillate8. The extraction of
light aromatic hydrocarbons (BTX) from petroleum
distillates with polar solvents, particularly
sulfolane, is reviewed in a paper presented on "The
Sulfolane Extraction Process" by H- Voetter and W.C.
Rosters before the Sixth World Petroleum Congress in
June 1963 (Paper No- III in Section II, pages 131 to
145). ~his extraction proce8s was apparently
limited to the uge of highly aromatic catalytic
reformates, pyroly~i9 ga~oline and coke oven gaso-
line. In contragt to these feed8, the gasoline
range feed of the present invention has a relatively
low percontage o~ aromatic~ and high percentage of
straight chain aliphatic hydrocarbons, largely
1-n-olefins. While the proces~ of the prior art was
simply directed to BTX production, aliphatic hydro-
carbons, particularly olefins, are important co-
products of the present process. These aliphatic
hydrocarbon rich fractions are for example advan-
tageously used as feeds in the urea adduction
process.
U.S. Patent 3,755,15 by H. Akayabashi, S.
Hoshiyama and S. Takigawa disclosed that acetyl-
pyrrolidone and its solvent mixtures are uniquely
suitable compared to sulfolane and other known
solvents for the stepwise extraction of cracked
petroleum oils of undefined origin. In the first
st-p, the aromatic hydrocarbon~ are extracted, in
the ~econd th- ol-fins and naphthenes. In contrast,
for the s-par~tion o~ thermally cracked petroleum
reQidua, sulfolane and simllar solvent~ were found
to be ef~ective in tho present work.
200449~
- 16 -
U.S. Patent 4,267,034 by c.o. Carter
described the selective extraction by dimethyl
sulfoxide-water mixtureg of the olefin componentS
of olefin-paraffin mixtures. A similar olefin
extraction by alcoholic solutions of silver and
copper salts is claimed in U.S. Patent 4,132,747 ~y
John F. Knifton.
No separation proces~es using solid
adsorbents were disclosad for thermally cracked
resldua of high sulfur and unsaturates content to
our knowledge. U.S. Patent 4,517,402 by R.N. Dessau
describes a process for the selective sorption of
linear aliphatic compounds frsm vacuum gas oil by
ZSM-ll type zeolites. This Dessau patent and the
patents cited therein, particularly U.S. Patent
3,709,979, indicate that for such separation zeo-
lites having appropriately small pore dimension and
high silica to alumina ratios are used. Most of
these zeolites were used for catalytic dewaxing as
described in U.S. Patents 3,894,938: 4,149,960. As
such they do not suggest the separation of a highly
reactive feed such aa a coker distillate without
concurrent reaction.
Eluent chromatography using highly polar
~olids such as silica gel was employed widely in
petroleum chemistry as an analytical method for
determining the types of compounds present. For
example, the analysis Or olefin-paraffin and aro-
matic hydrocarbon mixtur-s derived by wax cracking
is described using such a method by E. Kh.
Kura hova, I.A. Musayev, P. I. Sanin and A.N.
Rumyant~ev in Neftekhimiya, Vol. 7, No. 4, pages 519
2Q044~4
to 529 in 1967. However, these applications were
analytical rather than method9 for producing com-
ponents for indu~trial utilization.
In contrast to the prior art, the present
invention starts with linear olefinic products of
the high temparature thermal cracking of petroleum
residua, separates the straight chain hydrocarbons
of such cracked distillat2s and oligomerizes the
linear olefin component8 to liquid polyolefin
lubricant intermediates.
The final step in synthetic lubricant
manufacture is the hydrogenation of polyolefins.
Since the polyolefin intermediates of the prior art
contained no sul~ur compounds as impurities,
generally sulfur sensitive metal catalysts of
hydrogenation were employed. For example, the
previously discussed U.S. Patent 4,420,646 by Darden
et. al. particularly prefers a nickel-copperchromium
hydrogenation catalyst described in U.S. Patent
3,152,998.
In contrast to the prior art, the
hydrogenation step of the present process is pre-
ferably carried out in the presence of sulfur
insen~itive cataly~ts. Transition metal sulfide
based catalysts are particularly preferred. For
oxample, a CoS/MoS catalyst i9 used to advantage.
In general, such catalysts result in the conversion
of the sulfur compound impuritie~ and their removal
as hydrogen sulfide.
200~494
- 18 -
BRI~F DEScRIPTION OF THE F~GURES
Figure 1 illustrates by capillary gas
chromatograms the composition of light Fluid-coker
ga~ oil feeds containing major amount~ of 1-n-
olefins and n-paraffins plu~ various sulfur com-
pounds.
Figure 2 illustrates by capillary ~as
chromatogram9 the composition of mixtures of
l-n-olefin9 and paraffin9 separated from light
Fluid-coker gas oils.
Figure 3 illustrates by lH nuclear mag-
netic resonance spectrum of the vinylic region the
amounts of various types of olefin~ separated from
light Fluid-coker gas oils.
Figure 4 illustrates by 13C nuclear
magnetic resonance spectrum the chemical structure
of the main 1-n-olefin and n-paraffin components of
the product ~eparated from light Fluid-coker gas
oils.
SUMMARy O;F ~8~1~
The multistep process of the present
invention provide~ a less expensive route for the
manufacture of polyolefin liquid lubricants, i.e.,
i30paraffin~ derived via th- oligomerization of Cg
to C24 linear ole~ins. Such lubricants in the past
were optimally prepared via the trimerization
l-n-decene. The hi'gh C09t and limited availability
of l-n-decene is a ma~or factor in limiting the use
200~494
- 19 -
of poly-~-olefin (PAO) synthetic lubricants.
Synthetic lubricantS can be also derived from C1o to
C24 internal olefing. Howev-r, the ultimate start-
ing materials for thQ9e poly-internal oiefins are
also ~-olefins.
It was al80 proposed to derive synthetic
lubricants, from ~-ole~in products of higher mole-
cular weight paraffin cracking. A~ feedo for such
processes, waxes and ga~ oils were proposed.
However, these procesae~ ~re ~lso expensive s1nce
they start with valu~blo, low sul~ur hydrocarbon
~eed~tock~ and yield A whol- range Or olefins, many
of them not suited for polymerization to
poly-~-olefins.
In the present multistep process, below
liquid fuel value, sulfur containing petroleum
distillates of high ~-olefins content are employed
as the feed. These distillates, hereafter defined
as coker distillates, are derived by the high
temperature thermal cracking of petroleum residua,
i.e. vacuum resid~. Prefe~red processes producing
such coker distillates are Fluid-coking and
Flexicoking.
The coker distillates feeds of the present
process contain major amounts of l-n-olefins,
n-paraffins and greater than 0.1% concentration of
~ulfur, mo~tly in tho form of aromatic, thiophene
type, sulfur compounds. There Are also significant
amounts of con;ugated dienes pre~ent.
200~49~
- 20 -
Practional di~tillation of the cracked
coker product in th~ rQfinery u~ually provides heavy
coXer naphtha and/or light coker gag oil ractions,
This may suffice to provide appropriate molecular
weight range feed9 aY part of the coking process.
Additional fractional diBtillation may be needed to
obtain narrower carbon range feed~, e.g. a Cg to cl3
cut or a Clo cut. Thus, the prQsent coker dis-
tillate feeds are obtained either by ~imple refinery
distillation or additional fractional d~stillation.
The first st-p of th- pr sent process is
the enrichment in ~traight chain aliphatic hydro-
carbon components, particularly l-n-ole~ins, of the
coker distillate feed. Thl~ is acco~plished by one
or more Qf several separation processes. A pre-
ferred separation process is urea adduction. Urea
forms reversible, cry~talline complexes with the
l-n-olefin and n-paraffin components of the feed.
These complexes are then separated by filtration and
decomposed to give an enriched feed. A preferred
alternative to urea adduction is crystallization.
It was surprisingly found that cooling broad dis-
tillate fractions of higher olefins containing three
or more different carbon atoms results in the
~eparation of cry~talline mixtures of l-n-olefins
and n-parafflns.
Other less prQfsrred methods of separation
include liguid-liquld xtraction, membrane separa-
tion and adsorption on solids ~uch as silica gel and
zeolites. The~e method~ can be used alone or as the
first step in a two step separation process. For
exampla, extraction or membran~ separation may be
Z00~494
- 21 -
used to reduce the aromatics content, prior to the
separation of l-n-paraffin8 by crystallizatiOn.
~ he second 5tep of the instant process is
the polymerization, i-e- selective oligomerizatiOn
of the line~r olefin co~ponent8 of th~ enriched feed
containing sulfur compound~ to produce appropriately
branched polyolefin~. Tho polyole~in products of
this step are mixtures of dimerg, trimer~, tetramers
and pentamers. The oligomerization is preferably
carried out in tho pr-sence of acid, i.e. cationic,
catalysts. A sp-cifically pre~erred type of
catalysts is the Friedel-Crafts type such as BF3 and
AlCl3. The oligomerization can be carried out in
one or two stsps. In a two step process, olefin
dimers may be produced in the fir~t ~tep. These
dimers may be then codimeriz-d with c-olefins in the
second step.
The third and final step of the instant
process is the hydrogenation of the sulfur contain-
ing polyolefin product of the s-cond step, prefer-
ably in the presence of transition metal sulfide
catalysts. This hydrogenation results in a sulfur
free isoparaffin product of appropriate branchiness.
Such an isoparaffin ha~ a high viscosity index, good
low temperature flow prop-rties and an outstanding
high temperature stability, i.e. the d-sired charac-
tori~tic3 of a polyolefin derived synthetic lubri-
cant.
The polyolefin precur~or of the synthetic
lubricant produced via the prQsent multistep process
i~ a copolym-r of ma~or amounts of 1-n-012fins, i.e.
200~494
- 22 -
~-olefins, including even and uneven numbered carbon
compounds. As minor co~ponents such copolymers also
contain units derived from linear internal olefins
and methyl branched ol~fins- ~he incorporatiOn of
these minor comoncmers into the present isoparaffin
lubricants results in a uniquQ balance of properties
de irable in variou~ lube application~.
DESCRIPTION OF THE PR~ ~B_~L~r~5 ~ ~
The multistep proce~ of the present
invention i8 to manufacturo polyolsrln type synthe-
tlc lubricants, derived mostly rrOm Cg to C24 linear
olefin components of coker distillat- fractions
containing more than 0.1% ~ulfur. The~e coker
di~tillatos are produced by the high temperature
thermal cracking of petroleum residua. The process
comprises the following three ~teps:
a) Enrichment of a coker distillate feed
in 1-n-olefin and n-paraffin components by one or
more separation processes including urea adduction
or crystallization,
b) Oligomerization of the C8 to C24
olefin components of an enriched coker distillate
fraction to produce sulfur containing C30 to C60
polyolefins, and
c) Hydrogenation o~ the sulfur containing
polyoleflns to isopararrln~ with the simultanoous
removal of the sulfur.
200~49~ .
- 23 -
The coker di9tillates of the present
invention contain l-n-olefins as the ma~or type of
olefin components. The percentage of the Type I
olefins is preferably more than 30% of the total
olefin~. The preferred di9tillate~ contain organic
sulfur compounds in concentration~ exceeding o.s
wt.% 8UlfUr equivalent.
In the ~ir~t step of tho present process,
the coker distillate feed i~ enriched in 1-n-olefin
and n-paraffin components. Sp-ciSically, preferrod
~eparation proces~e~ ~or enrichment include the urea
adduction and crystallization of these components.
In the second stQp of the present process,
the Cg to C24 olefin components of an enriched coker
distillate fraction are oligomerized to sulfur
containing C30 to C60 polyolefins, preferably in the
presence of a Friedel-Crafts catalyst, most prefer-
ably in the prasence of a boron trifluoride complex
catalyst.
In the third step, the sulfur containing
polyolefins are hydrogenated to isoparaffins with
the simultaneous removal of sulfur as hydrogen
sulfide in the prQsence of tran~ition metal sulfide
cataiysts.
The present invention also covers a novel
polyole~in type synthetic lubricant composition
derived moatly from Cg to C24 linoar olefins,
proferably Cg to C13 1-n-olofin rich linear olefins
200A~494
- 24 -
wherein said olofin8 contain l-n-olefins as major
components and int~rnal n-olefins and methyl
branched componentg a~ minor components, and
said olefin mixtur~ is separated from a coker
distillate feed containing l-n-olefins and n-paraf-
fins as ma~or components, and oligomerized in the
presenCQ o~ acid catalyst~ to a polyolefin compris-
ing 2 to 6 monomer units, ~aid polyolefin product
mixture containing n-paraffina then being hydro-
genated to provide a mixtur~ o~ i~oparafrin lubri-
cants and unconvertod n-para~f in~ from which the
para~fins are then removed prererably by dlstil-
lation or said mixtur~ o~ n-olefins and n-paraffins
is first sub~ected to distillation to remove the
paraffins and then hydrogenated to provide the novel
isoparaffin lubricant~.
SPECIFIC DETAILS OF TH~ EMBODIM2NTS
The specific deta$1s of the embodiments of
the present invention will be di~cussed in terms of
the hydrocarbon fdeds and separation processes
employed. Separation via urea adducts will be
particularly discussed. Thereafter, the selective
conversion of the n-ole~in components of the
n-olefin and n-paraffin mixture~ obtained in the
sep~ation step will be discussed. Oligomerization
to synth-tic polyole~in lubricants will be
particularly described.
Oleflni~ It~a~LlY Crack~ Feeda
Th~ pr-rerred hydroc~rbon f~eds of the
pre-ent invention contain ma~or amount~ of olefins,
2004c4~ `
paraffins and aromatic compounds. More preferably
the feeds also contain significant amount of sulfur
compounds. A detailed description of the most
preferred feeds, i.e. distillate feeds, produced
from petroleum residua by high temperature thermal
cracking processes such as Fluid-coking and
Flexicoking,is found in U.S. patent 4,711,968.
The olefinic feed of the present process
is a critical factor in producing the polyolefin
lubricants of the present invention at a low cost.
Such a feed is produced by high temperature thermal
cracking of petroleum residua. The percentages of
l-n-olefin and other olefin components of petroleum
distillates generally increase with the temperature
of cracking.
Thermal cracking processes produce hydro-
carbons of more linear olefinic character than
catalytic cracking. The presence of linear olefin
components, particularly l-n-olefins, in the cracked
distillates is important in producing an olefin-
paraffin mixture of high l-n-olefin content in the
separation step. l-n-Olefins are more readily
oligomerized than internal n-olefins. They lead to
polyolefins and, in turn, isoparaffins containing
longer alkyl branches than the corresponding inter-
nal linear olefins. An appropriate number and
length of alkyl chains is critical for the high
performance of isoparaffin products.
Z00~494
- 26 -
There are two main commercial processes
for producing thermally cracked petroleum distil-
lates from residua- Thay were reviewed by ~ens
Weitkamp in the ~ournal, entitled ChQm. Ing. Tech.
No. 2, pages 101-107 in 1982- These processes ar~
coking and visbreaXing, representins ~evere and mild
cracking processes. Th~ main coking processes are
Flexicoking and Fluid-coking which produce the
preferred distillat- feedg of the present invontion,
Suitabl- distillate f-ed~ can b- also
preparod in thexmal procosses employing a plurality
of cracking zones at different temperatures. Such a
process is descri~ed in U.S. Patents 4.477.334 and
4,487,686. Each of these thermal cracking processes
can be adjusted to increase the olefin content of
their products. Heavy ga~ oil distillates can be
further cracked to increase the a~ount of lower
molecular weight olefin~.
The coker distillate feeds of the present
invention are preferably in tha Cg to C24 carbon
range where the linear olefins and n-paraffins can
be separated via urea adduction or crystallization.
Light coker gaC oil refinery fractions are usually
in that carbon range. The preference for fractions
within this range depends on the specific use
requirement~ of the polyole~in lubricants to be
produced.
The preferred cr~cked distillates of the
present feed contain relatively high amounts of
organic sulfur compounds. The sulfur concentration
i9 preferably greater than O.lS ~1000 ppm), more
200~49ta
- 27 -
preferably greater than 1% (10,000 ppm). The
prevalent sulfur compounds in these feeds are
aromatic, mainly thiophenic- Mo8t preferably the
aromatic sulfur compounds r~pro8ent more than 90% of
the total. This finding ig important for the
prosent process since thiophen~g, benzothiophe~es
and similar aromatic sulfur compounds do not inhibit
the separation of the desired 1-n-olefins.
The olefin containing distillate fractions
of thermal cracking proce~es mny be employed as
feeds in the proceQs of the invention without prior
purification. However, these di~tillate fractions
may optionally be treated prior to their use to
reduce the concentration~ of aromatic hydrocarbons
conjugated dienes, sulfur and nitrogen compounds if
so desired. For example, aromatic hydrocarbons and
sulfur compounds can be selectively extracted from
the olefin containing fraction by polar solvents. A
similar separation of aromatics from aliphatic
compounds can be achieved using membranes. Shape
selective zeolite adsorbents can be also used for
the separation of n-olefins plus n-paraffins.
.
Nitrogen and sulfur compounds in general
can be removed by use of absorption columns packed
with polar solids 3uch aq silica, Fuller's earth,
bauxite and tho like. Sulfur compound~ can be also
removed by acid treatment. For example, treatment
with BF3 complexea can re~ult in the alkylation of
thiophene type sulfur compounds by the conjugated
diene and branched olefin components of the feed.
The conjugated olefin components o~ the present
200~49~
- 28 -
~eeds may also be removed by prior mild hydro-
genation to monoolefins.
The light coker gas oil (LKG0) feed from
the refinery is prefQrably furth~r fr~ctionated
prior to use in the present process. It is pre-
ferred to distill a ~orerun fraction of LKG0 up to
cl7 and u e it in the present process. Narrow gas
o~l fractions, containing al~phatic hydrocarbons
having as low as thrce di~er-nt carbon atoms, such
a~ Cg to Cll, can be al80 employed. How-vor, single
carbon LKG0 fractions cannot be utilized for linear
olafin plU8 n-paraffln sQparation by crystalli-
zation. The separation o~ single carhon LXG0
fractions such as an olefinic Clo fraction i8 though
possible via urea adduct$on.
The ole~in content of the present cracked
distillate feeds i~ above 30%. The 1-n-olefins are
the major type components.
The main olefin reactant components of the
present feeds are nonbranched Types I and II plus
mono-branched Types III and IV a~ indicated by the
following formulas (R = hydrocarbyl, preferably
non-branched alkyl):
R-CH'CH2 RCH-CHR R-~-CH2 R-C-CHR
I II III IV
non-branched linear mono-branched mono-branched
terminal internal terminal internal
25-45% 15-25% 10-20% 10-20%
2004494
- 29 -
The R groups in the formulas of the various types of
olefins can be straight chain or branched alkyl
groups. However, the alkyl groups of the preferred
coker olefins of Type I and Type II are predominant-
ly either straight chain or monomethyl branched.
Additionally, the Type III and Type IV olefin
components of these preferred feeds predominantly
possess a methyl group as one of the alkyl groups on
the completely substituted vinylic carbon. NMR also
indicated the presence of minor amounts of conjugat-
ed dienes ranging from 2 to 10% concentration. The
concentration of the various olefins generally
decreases with their molecular weight, i.e. carbon
number. Therefore, coker distillates having more
than 24 carbons per molecule are less preferred.
The paraffin components of the preferred
coker distillate feeds are present in concentrations
similar to but smaller than the olefin components.
The n-paraffins are the major sinqle types of
paraffins present. The branched paraffins are
largely methyl branched. Monomethyl branched
paraffins are prevalent.
The aromatic hydrocarbons of the present
feeds have a concentration range from about 6% to
about 50%. The percentage of the aromatic com-
ponentQ increases with the carbon number of the
distillate fractions. Of course the percentages of
olefins and paraffins decrease accordingly. In the
preferred Cg to C1g carbon range the concentration
of aromatics is between 10 and 50%.
200~494
- 30 -
The aromatic hydrocarbon components of
these feeds are predominantly unsubstituted parent
compounds such as benzene or substituted with methyl
groups such as toluene. The concentration of ethyl
substituted compounds is much smaller. Propyl
substituted aromatics are present in insignificant
amounts. Up to 12 carbon atoms, the aromatics are
benzenoid hydrocarbons. From cl2 to cl5 most
aromatics are of the naphthalene type. Among the
higher carbon number hydrocarbons most aromatics are
three member fused ring compounds such as
anthracenes and phenanthrenes.
The concentration and type of sulfur
compounds in the preferred coker distillates depend
on their carbon number. The sulfur concentrations
range from 0.1% to 3~. In general, sulfur
concentrations increase with the carbon number to
3%. In the Cs to C7 carbon range there are major
amounts of thiols present. The Cg and higher
fractions contain mostly aromatic sulfur compounds,
mostly of the thiophene type. The structure of
aromatic thiol components is similar to those of the
aromatic hydrocarbons. Methyl and ethyl substituted
thiophenes are present in decreasing amounts.
Alkylthiophenes are the major sulfur compounds in
the Cg to Cll range. Benzothiophenes are mostly
present in the Cl2 to C13 range. In higher boiling
fractions dibenzothiophenes are the major sulfur
compounds.
Separation yia Urea Adducts
200~494
- 31 -
The separation of normal olefin - n-paraf-
fin mixtures from distillates produced by the high
temperature thermal cracking of petroleum residua is
preferably carried out via urea adducts by methods
disclosed in the prior art. Most of these methods
were described by A. Hoppe in the previously refer-
red Chapter 4, pages 192 to 234 of Volume 8 in
"Advances in Petroleum Chemistry and Refining". The
commercial methods reviewed by Fetterly in Volume
36, No. 7, pages 147-152 in 1957 in Petroleum
Refiner are preferred. These methods are outlined
in the following.
In the first method methanol is used as an
activator solvent for urea. Another method employs
an aqueous urea solution as a reactant for cracked
distillates. In a third method crystalline urea
reactant is employed.
Other methods may employ mixed solvent
mixtures for urea such as aqueous isopropanol and
aqueous methyl i-butyl ketone. The choice of
solvent or solvent mixture is influenced by the
solvent's characteristics and cost plus the ease of
urea and solvent recycle after the decomposition of
the complex. It is desirable to have a volatile
solvent or solvent mixture which is not only a good
solvent for urea but also has some miscibility with
the cracked hydrocarbon feed. In a preferred case,
contacting the urea solution reactant with the
hydrocarbon feed results in the formation of a solid
urea adduct precipitate and a liquid unconverted
200~494
- 32 -
reed - excess reactant mixture from which the
roactant i readily separated e g by distillation
and water 0xtraction
The urea reactant is employed in several
fold molar excess over the 1-n-olefin plu- n-paraf-
fin componants of the feed The molar ratio of urea
to tho l-n-olefin plug n-paraffin compounds is
preferablY 5 or more Increa~ed ratio~ result in
increa~od amounts of adduct precipitate However,
the ratio of urea to the n-aliphatic hydrocarbon~ in
such adducts increases Thus the yield of separated
aliphatic hydrocarbon product per weight o~ urea
decreas-s
The solid urea adducts formed are separat-
ed preferably by ~iltration The ~iltered adduct is
voluminous and is advantageously washed with a Cs to
C8 hydrocarbon ~olvent, prefarably isooctane, to
remove the occluded feed and reactant solution
The separated urea adduc~s are decomposed,
preferably by he~ting, to recover a mixture
1-n-olefins and n-paraffins In a preferred opera-
tion, the adduct i~ added to a hot, stirred water
which di~olv-s th- urea by-product of decomposi-
tion The l-n-olefln - n-paraffin product mixture
is insoluble in the water and as such separates as a
top hydrocarbon phase
Th- hydrocarbon produot con~ists malnly of
1-n-ol-rin~ and n-para~rins Th- combined percent-
age of l-n-olerins and n-para~ins i~ preferably
greater than 75% Th~ ratio o~ the l-n-olefin
,
,
:'' ' ' .
200~49~ .
- 33 -
versus n-parafrin component~ depends on their ratio
in t~e feed and t~o extent o~ adduct for~ation in
the complexing step With increasing amounts of
adducts formed incr~asing amounta o~ the ~ore
soluble l-n-olefin complexes precipitate Th~ ratio
of l-n-ole~in~ to n-paraffin~ i~ pr-ferably from
about 0 4 to about 1 5 With th- more pre~erred C10
to Clg Flexicoker feed~, ratio~ ranging from about
0 6 to about 1 2 were found
SoDaration Via Cry~talliz~ion and Othar M~th~ds
A pra~erred m thod of separation employs
selective cry~tallization of the di~tlll~te feed,
preferably from solution Thi process comprises
the separation by crystallization Or a petroleum
distillate fraction, containing major amounts of
l-n-olefins and n-paraffina with at least two
preferably at least three different carbon numbers
per molecule, to obtain cry~tals mostly consisting
of l-n-olefins and n-paraffins
Prior to separation by crystallization the
~eed is preferably diluted with a volatile solvent
Preferred solvents are selected from the group of
hydrocarbon~, oxygenated sol~ents and C02 Exem-
plary solvents are propylene and methyl ethyl
Xetone Crystallization is effected by cooling the
~eod The cryatals formed are separated, for
example by filtration uaing techniques developed for
lub~ oil dewaxing and p-xyl-n- s-paration
To enhanco filtration, crystals containing
n-para~fins and 1-n-ole~in~ are preferably modified
200~9~
by additives. AdditiVe~ developed for wax crystal
modi~ications are effective- For oxample, a co-
polymer of ethylen~ and vinyl acetate, Paranox 25,
and the like can ~e u5ed- Such additive9 control
crystal growth. Thu9 mor~ readily filterable and
washable crystal8 with legg occluded impurities are
produced. For the production of crystals of high
purity, the washcrystal method ig particularly
suited. Uging thig method the paraffin-olefin
crystals are wa~hed with the melt of the same to
remov~ impuritie~.
Another preferred method of separation in
the present process employs liguid-liquid extrac-
tion. This process comprises the separation by
extraction with a polar solvent of a petroleum
distillate fraction derivQd via the high temperature
thermal cracking of petroleum residua, i.e. a feed
containing ma~or amounts of l-n-ole~ins, n-paraffins
and greater than 0.1% sul*ur to provide an extract
enriched in aromatic hydrocarbon and sul~ - com-
ponents. The polar solvents are preferably selected
from tha group consisting of organic nitrogen,
oxygen, sulfur and phosphorus compounds.
Exemplary organic nitrogen compounds are
amines, amide3 and nitriles ~uch as triethanolamine,
N-methylpyrrolidone, dimethyl~ormamide, ace-
tonitrile, ~, ~- oxydipropionltrile, 1,2,3- tris-
(2-cyanoethoxy) propan-. Examples of organic
oxygen, sulfur and phoophorus compounds are ethylene
carbonate, dlethylenQ glycol, tetraethylene glycol,
butyrolacton-, methanol, ~ulfolano, diethyl sulfone,
trimethylphosphate. Th- selectivity of most of
2(:)0~4~
- 35 -
these polar organic compound~ can be enhanced by the
addition o~ appropriately minor amounts of water.
The suitability of a solvent is mainly
determined by its group selectivity. This is
directly related to the polarity of the solvent.
The groups of intere9t are aromatic compounds
including sulfur containing aromatics on onR side,
olefins and paraffin~ on th- other. Group selecti-
vity changes with increasing boiling ranges of the
feed since the character Or the aromatic components
changes from mononuolear to dinuclear compounds,
etc. With an increasing number of fu ed aromatic
rings, the polarity o~ the present feed components
increases. Thus the selectivity is also increased.
Another important factor i~ solvent power
which determines the amount of solute contained in
the solvent phase. As such, it affects the economy
of a given solvent. The third basic factor is
solvent select$vity for low versus high boiling
components, e.g. light-heav,v selectivity. This
selectivity factor should be usually at a minimum.
However, since the feed o~ the present invention is
preferably a narrow distillate cut, the value of
this ~actor has often no e~fect on the separation.
The solvent is usually higher boiling than
th- cokcr distillat- feed. Thus, the extracted
dlstlllat- components can b- recovered by fractional
dlstillation and the solvent recycled. Alternative-
ly, especially in cas- of high boiling coker gas oil
fractions, the ~olvent can ba much lower boiling.
In ~uch a cas~ the solvent i~ recovered as a
~00~494
- 36 -
distillate and the extract remains as a residual
product. The solvent can be also recovered from the
extract by membrane separation. For example,
acetonitrile is a highly suitable solvent for
recovery by the membrane technique.
Another preferred method of separatiOn
employs a solid ad90rbent such as clay, alumina,
alumino-silicates, fuller5 earth, gilica gel. These
adsorbents when contacted with the present distil-
late feeds of high temperature thermal cracking
generally effect separation into a fraction enriched
in aliphatic compounds and a fraction in aromatic
hydrocarbon and sulfur components.
one group of adsorbent3 consists of highly
polar materials. They are hiqhly polar solids such
as silica gel or solids covered by a highly polar
stationary phase such as polyethylene glycol on a
solid carrier. Such solids effect chromatographic
separation. When in contact with the present feed
they retain the components of the present feed in
proportion to their polarity. Using a narrow
distillate fraction as a feed, the paraffin compon-
ents are eluted at first followed by the olefins and
then by the mononuclear and binuclear aromatics,
etc.
Combined Separation Proce~se~
The separation process steps of the
present invention can be advantageously combined
with each other or with selective chémical conver-
sion processe~ to provide ~ingle types of chemicals
2(~0~494
based on Flexicoker distillates. In the following
the~e combinations will be discussed in some detail.
The separation by crystallization of
1-n-olefin - n-paxaffin mixtures can be combined
with their furthar eeparation using molecular sieves
to provida l-n-olefins containing both even and
uneven numbers of carbons per molecule. Alter-
natively, the mixtures can be first distilled to
obtain single carbon fraction~. The n-paraffins can
then be selectively cry~talliz-d and ~eparated from
the n-olefin rich liquid phase.
Instead of further separation, the
l-n-olefin component~ of the~e mixtures of
l-n-olefins and n-para~fin~ are preferably reacted
selectively leaving unconverted n-paraffins behind.
For example, the 1-n-olefin~ can be hydroformylated,
i.e. reacted with CO nd H2, to provide aldehydes
and/or alcohols o~ high linearity. They can be
reacted with aromatics ~uch as phenol to produce via
alkylation tho corresponding linear alkylaromatic
compounds, i.e. alkylphanols. The l-n-olefins can
be also oligomerized, preferably by acid catalysts,
to provido low molecular weight polyolefins.
The aliphatic raffinate can also be
reacted ~electively to convert to olefinic com-
ponents and leave a mixturo o~ paraf~ins uncon-
verted. Selective reaction~ for olefin conver~ion
are the same as discus~Qd above.
The aromatic extract can be further
separated for example by crystallization. E.g.
200449~
-- 38 --
p-xylene, durena and naphthalene can thus be
separated. Alternatively~ the aromatic extract can
be selectively hydrogenated to remove the sulfur
compounds present. The aromatic compounds in the
presence and in the absenc~ o~ thiophenic sulfur
compounds can be alkylated with olefins to provide
alkylaromatiC product5 with or without sulfur. The
alkylation of dinuclear aromatic~ with higher
ol~ins, prefQrably in the cls-c30 rang~, is pre-
ferred to provide nonvolatile ~olvents.
Conversion~
The ole~in components o~ n-olefin plus
n-para~fin mixture~ obtained in the present separa-
tion proces~ are advantageously convertod to higher
boiling derivatives and then separated from the
unreacted n-paraffln~. The~e conversions generally
comprise known chemical reactions and processes.
The preferred conver~ions are oligomerization,
alkylation of aromatic compound~ and carbonylation
of olefins. A preferred aspect of the present
invention is a unique combination of separation via
urea adduction or crystallization and selective
conver~ion of n-olefin plus n-paraffin mixtures
followed by the separation o~ the n-paraffin.
Th- pre~erred mixture~ of n-olefins and
n-paraffins of the present invention contain
l-n-ol-~ins as the main olefinic components. These
l-n-olefins are th- pr-f~rred reactants in numerou~
types of conversion- which ar- more specifically
polymorization, particulnrly oligomeri2ation,
al~ylation, carbonylation and variou~ other olefin
: 200~4~4
- 39 -
conversions. In the following, mainly the
conversion of l-n-olefins to oligomers will be
discussed. Internal n-olefins generally undergo
similar conversions at a lower rate.
The acid catalyzed and free radical
oligomerization of l-n-olefins is widely known. In
the present process acid catalysed oligomerization
in the liquid phase is preferred. The catalysts are
generally strong acids such as phosphoric acid,
sulfonic acid, aluminum chloride, alkylaluminum
dichloride and boron trifluoride complexes. Boron
trifluoride complexes are preferably those of protic
compounds such as water, alcohols, and protic acids.
Using BF3 complexes, cracking side reactions are
avoided.
The oligomerizations are generally carried
out in the -100 to 100C temperature range at
atmospheric pressure. Superatmospheric pressure may
be used to assure a liquid phase operation. The
number of monomer units in the oligomer products is
2 to 30, preferably 2 to 6.
The most preferred oligomerizations
produce polyolefin intermediates for synthetic
lubricants. The preparation of synthetic lubricants
via the polymerization of even numbered, pure
l-n-olefins was reviewed by J.~. Brennan in the
journal, Ind. Eng. Chem. Prod. Res. Dev., Vol., 19,
pages 2-6 in 1980 and the references of tbis arti-
cle. Brennan concluded that isoparaffins, derived
from 1-n-decene via trimerization catalyzed by boron
200~49~ .
- 40 -
trifluoride followed by hydrogenation, possess
superior lubricant properties. Due to the position
and length of their n-alkyl chains these trimers
also exhibit superior stability. Their viscosity is
relatively insensitive to temperature changes.
Based on these and similar studies Cg, Clo and C12
~-olefin based lubricants, having 30 to 40 carbon
atoms per isoparaffin molecule, were developed.
More recently synthetic lubricants were
also developed on an internal olefin basis. U.S.
patents 4,300,006 by Nelson and 4,3}9,064 by
Heckelsberg et al. discuss the synthesis of such
lubricants via the BF3 catalysed dimerization of
linear internal olefins derived via ~-olefin
metathesis of lubricants via the codimerization of
linear internal and terminal, i.e. ~-olefins.
According to the present invention, the
n-olefin components of a mixture of n-olefins and
n-paraffins are converted into oligomers by reacting
them in the presence of an acid or a free radical
catalyst preferably and acid catalyst. In a pre-
ferred conversion step. oligomers containing an
average of 3 to 4 monomer units, i.e. trimers and
tetramers, are produced by reacting a mixture rich
in C~ to C13 l-n-olefins and n-paraffins, in the
presence of a boron trifluoride complex. In an
alternative step, the l-n-olefin and internal normal
olefin components of a C13 to C17 mixture of
n-olefins and n-paraffins are cooligomerized to
200~494
produce oligomers containing an average of 2 to 3
monomer units.
Another preferred acid catalysed oligomer-
ization of n-olefins, produces polyolefins in the
Cl6 to Cso carbon range. These are subsequently
used to alkylate benzene to produce C16 to C30
alkylbenzene intermediates for the synthesis of oil
soluble Ca and Mg alkylbenzene sulfonate detergents.
The preferred alkylating agents are dimers.
The unconverted paraffin components of the
n-olefin oligomer product mixture are removed
preferably by distillation. The distillation is
performed either right after the oligomerization or
subsequent to the next conversion step comprising
either hydrogenation to isoparaffins or benzene
alkylation by the oligomers to alkylbenzenes.
Phenol alkylation by n-olefins leads to
linear alkylphenol intermediates of ethoxylated
surfactants. Phenol is highly reactive and can be
readily alkylated in the presence of a, crosslinked
sulfonated styrene-divinyl benzene resin, Amberlyst
15, at 80 to 150C.
Example
.
~(~0~:~49~
- 42 -
Separation of tho ~-Olefin Plus n-Paraffin
Components o~ Light Plexicoker Gas Oil (LKGO)
bv Addina the Oil to a Methanoli~ Urea Solution
To a solution of 510 g urea in 3 L
methanol soo mL (789.6 g) o~ stirred light
Plexicoker gas oil was added. Precipitation of
yellowish urea adduct~ occurred immediately. After
45 minutes of stirring, th- mixture wa~ filtered
with suction and washed threo time9 each with 300 ml
isooctane to obtain 368g white cry~talline adduct.
The filtrate of the reaction mixture
separated into a lower oily phase (about 10%) and an
upper methanolic phase ~about 90%). GC analysis
indicated that the methanol dissolved some of the
lower molecular weight components of the ga~ oil.
Washing with i-octane removed methanol (about 80%)
and additional amounts of the oil (about 20%) from
the adduct.
Tho adduct was dried in vacuo overnight to
remove the re~idual i-octane (about 65%) and
methanol (about 35%). The remaining dry adduct,
213g. was added to 1800 ml of water and stirring.
The stirred mixture wa~ heated to 70'C to complete
tho decompo-ition of the adduct and then allowed to
cool to room temperatur-. This resulted in the
soparation o~ 44g o~ an upper hydrocarbon phase.
The lower, hazy water pha~e yielded an additional
1.8g o~ hydrocarbon- on extraction with 600 ml of
hexan-. Thus the total yield wa~ 9 wt~wt~ based on
the feed.
200l~494
- 43 -
A comparative analysis of the hydrocarbons
recovered via urea adduction and of the light
Flexicoker ga9 oil feed by capillary gas chroma-
tography indicated a great enrichment of the re-
covered hydrocarbons in the 1-n-olefin and n-paraf-
fin components. Thi~ is illu~trated by the gas
chromatograms in Figures 1 and 2.
The upper part o~ Figure 1 shows the gas
chromatogram recorded by a Flame Ionization Detector
of tho organic compounds in general. The tall
doublet peak~ indicato th~ pre~-nce Or l-n-olefln -
n-para~fin pairs of th~ same carbon number in the
C10 to C26 range. These ar- the largest single
compound components of the mixture. The l-n-olefin
component is always of a shorter retention time than
the corresponding paraffin. In the Clo to C16
range, the l-n-olefin componemts are present in a
larger concentration than tho n-paraffins. The
unresolved hump of the figure indicates the presence
of an extremely high number of individual components
present.
The lower part of Figure 1 shows the
corresponding chromatogram for sulfur compounds. It
is noted that the sulfur detector had a near to
square response to sulfur concentration. A compari-
~on of th~ peak heights of the sulfur compound
components with that of a ~tandard sul~ur compound
contalninq lQO ppm sulfur indicates the presence o~
numerous sul~ur ¢ompound- at greater than 100 ppm
sulfur concentration.
200~49~
- 44 -
The upper part of Fi ure 2 shows the FID
chromatogram oS the l-n-olefin - n-paraffin mixture
separated from the light Flexicoker ga~ oil feed of
Figure 1. The tall l-n-olefin -n-paraf~in doublet
peaks of thi~ figur~ represent ~ore than 90% of this
mixture. Combin~d gas chromatography mass spectro-
metry showed that minor distingui~hable components
Of the mixture are 2- and 3-olefins, 2-methyl
substituted 1-ole~ins and 2- plus 3-methyl
substituted n-alkenes.
A comparison o~ th~ r~lative GC FID peak
intensities o~ Figuro 1 and Figure 2 show3 that the
l-n-olefin to n-paraf~in ratio o~ thQ separated
product is decreased. Tho olefin separation was
les~ efficient than n-paraf~in separation. n-Paraf-
fin recovery was particularly efficient in the
higher C20 to C26 region.
The lowar part o~ Figure 2 similarly shows
the S specific ga~ chromatogram of the hydrocarbons
separated via urea adduction. A comparison with the
S specific GC of the feed in Figure 1 shows a
tremendous reduction of sulfur content. All the
remaining sulfur compounds of Figure 2 are present
in concentration~ equivalent to or less than loO ppm
~ul~ur. It i~ also apparent that the remaining
sul~ur compounds are not the main sulfur compounds
o~ the ~od. The main sul~ur compounds o~ the feed
~à~e aromatic~ such a~ benzothiophenes and dibenzo-
thiophenes. The main sulfur compounds remaining in
the product appear to be homologous n-alkyl mer-
captan
20~49~
- 45 -
To obtain further information on the minor
hydrocarbon componentg of the product, high resolu-
tion nuclear magnetic rQs~nanC~ (NMR) spectometric
analyses were also performQd. Th~ lH and 13C NMR
spectra are shown by Figureg 3 and 4, respectively.
The lH NMR 3pectrum showed the prssence of
methylene, methine and methyl protons plus the
vinylic protong of the ol~inic groups. Aromatic
protons were e9sentially ab9ent. The relative
amounts o~ the various types of olef lns WerQ indi-
cated by the relative intensities of the various
vinylic hydrogens bstw~en 6.5 and 4.5 ppm a3 shown
by Fi~ure 3. Tho intense peak~ betwQen 4.8 and 5.0
and 5.64 and 5.8 ppm showed that the Typs
monoolefins having monosubstituted vinyl groups,
R-CH-CH2 are the most common type. Type I olefins,
of cour3e, include l-n-ole~ins, onD of the most
co~mon type Or compounds of the present mixture
according to GC. The other significant peak found
at 5.75 ppm in the 5.15 to 4.95 ppm refion is due to
the s~metrically disubstituted vinyl groups,
-CH=CH-, of type II olefins. The linear internal
Qlefins ~elong to this group.
In addition, th~re wer~ very small peaks
in the 4.5 to 4.8 ppm region commonly assigned to
th~ hydrogens o~ the unsymmetrically disubstituted
vinyl groups, R2C-CH2. of Type III olefin~. The
~-methyl substitutQd terminal olefin components of
this type had a ch-mlcal shift value of about 4.6S
ppm. Thera were also som- poaks in t~e 5.0 to 5.2
chemical shift region which i~ normally ~or the
vinyl~c hydrogen of the trisub~tituted olefins,
20~ 9~
- 46 -
R-CH-CR2, o~ Type IV. These peaks were presumably
due to monobranched olefin~ having -CH=C(CH3)2
group~. There was also an indication of the
presence of linear conjugated diolQfins, presumably
having structural unit3 of the formula
-CH=CH-CH--CH--.
The 13C NMR spectrum, con~irmed the
structure of the components indicated by GC/MS and
H NMR. As indicated by the ~igure, characteristics
13C peaks were found ~or th- inner methylan~ groups
and the terminal methyl group and th- ad~acent
methylenes. Addition~lly, in the olefinic carbon
region~, the inten~e pQaks o~ the -CH-CH2 carbons of
the l-n-olefins and the variou~ less intense carbon
peak-~ of the Type II and Type III olefins were
observedO The spectrum showed no indication of
other than methyl carbon branching.
Example 2
Separation of the ~-Olefin Plus n-Paraffin
Components o~ LKGO by the Addition
of a Methanolic Urea Solution to the Oil
A solution of 1020g urea in 6L methanol
was ~lowly added to 1800 ml (1592g) of w211 stirred
light Flexicoker gas oil. By tha time 500 ml urea
wa~ added a yellow precipitate started to form.
A~ter all the urea wa8 Added, gtirring of the
resulting su~pen~ion wa~ continu~d for an hour.
The final reaction mixture was worked up
in a manner de~crib2d in Example 1. The amount of
dry urea adduct obtained wa~ 506g. On treating the
200~494
adduct with hot water, 106g of ~-olefin -n-paraffin
mixture separated ag a top phage. Hexane extractiOn
of the aqueoug phase and ~ubsequent removal of the
hexane by fil~ evaporation resulted in the recovery
of another 4.5g product- Thus the total yield of
the product was 110.5g (6.9%).
The oil plUQ m~thanol filtrate was cooled
in a -20-C freezer for 4 hour-, then filt~red to
obtain additional urea adducts whlch were washed
with isooctane and dried in vacuo as usual. In this
manner an additional 300g of adduct was obtained
which on treat~ent with hot water provided 61.5g
(3.9~ olefin - n-paraffin product mixture as an
upper phase. A subsequent extraction of the lower
water phase provided an additional 2 g (0.1%)
product. Thus altogether 174g (10.9%) product was
obtained.
A comparison of capillary GC's of the
product fractions showed that the second batch of
oil product (61.5g) derived from the urea adduct
crystallized from the cold reaction mixture con-
tained less n-paraffin than 1-n-olefin in contrast
to the first batch and the products of the first
example. In the second batch, the percentage of the
internal olefins and monomethyl branched paraffins
al~o increa~ed. Cooling o~ the reaction mixture
apparently increa~es the yiold Or the total olefins
but result~ in a decrea-e of the ratio o~
l-n-oleflns to the total olefins. Sul~ur specific
GC's also indicated that the number and concen-
trations of ~ulfur co~pound~ wore much higher in the
second batch of product.
-` 200~49~
- 48 -
Example 3
Separation of the ~-Olefin Plus n-Paraffin
Components of LKGO by the Addition of a Methanolic
Urea solution to the Oil and S~bsequent
Coolina o~ tho Mixture
A methanolic solution of 1020g urea was
reacted with 1800 ml (1578g) Flexicoker gas oil in a
manner described in tho previou~ example. The
stirred reaction mixture was then cooled with ice to
7-C. Therea~ter, th- crystalllne urea adduct was
~iltered, wa~hed, driQd and reacted with hot water
as before. This re~ult~d in the separation of 94g
product. A subseguQnt extraction o~ the water phase
with 500 ml and then 200 ml hexane, provided another
65g product. Thus the total yield was 159.lg
(10. 1%) .
GC analyses showed that the composition of
the two product ~raction~ was virtually the same.
Both fractions contained a slightly higher concen-
tration o~ ~-olefins than the product of the first
example.
Example 4
Separation of the ~-Olefin Plus n-Paraffin
Components of LXGO by th- Addition to the
Oil of an Increased Exc~ss of Urea in Methanol
A warm (50-C) solution o~ 2000g urea in 8L
methanol wa~ addod to 1800 mL (1578.4g) light
Flaxicoker gas oil with st$rring. The resulting
reaction mixture was stirred for 90 minutes and then
cooled by an ico wator bath to 10-C with continued
z00~4~4
- 49 -
stirring. Thereafter~ the ~ixture was worked up andthe adduct reacted with hot water as in the previous
example to provide 173-2g (11%) of oil as the main
product. A subseqUent extraction of the water phase
with hexane (2x500 ml) and ether (2x500 ml) resulted
in 15.5g and 7.6g additional products of the same
composition, rQspectively. Thus the total yield of
the combined product was 12.4%.
The composition of the product was dater-
mined by capillary GC and i3 shown by Table I.
-` 200~494
-- so --
Table I
~-Olefin and n-Paraffin Content of Linear
Hydrocarbon Mixture Derived from
L~qht Flexicoker Gag Oil Vi~ Ure~ Adduction
l-n n- Ratio,
olef~n~ Paraf~in,
C~. ~ 5~, C~/C-, I
~10 0 08 0 13 0 66
Cll 0 ~8 1 88 0 75
C12 4 03 5 21 0 77
C13 6 36 6 98 0 91
C14 7 87 7 48 1 05
C15 7 70 7 41 1 04
Cl6 6 23 6 34 0 98
C17 4 18 3 62 1 15
Clg 1 25 1 98 0 63
c2o 0 64 1 20 0 56
C21 0 33 0 70 0 46
C22 0 18 0 43 0 41
C23 0 12 0 24 0 47
C10-C23 43 0 45 3 0 95
Table I shows the p-rcentage- Or the l-n-olefin and
n-par~in components of dif~-rent carbon numbers
The total percQntago of the ~-ole~ins is 43~ Most
o~ these ole~ins (36 4%) are in the C13 to C17
rang- The overall r~tio o~ ~-ole~ins to n-olefins
i8 close to one (0 95)
,
200'~49~
- S1 -
It was noted that th- dry weight of the
urea adduct in thl9 ~xa~ple was 6.4 times greater
~han that o~ the final product. In the previous
examples the adduct to produce weight ratio was
ranging from 4.7 to 5-4- This indicates that the
excess urea reactant may crystallize from the
reactant 901ution without adversely affecting the
separation proces~.
a~a3~
Separation of the ~-Olafin Plus n-Paraffin
Components of LXGO by the Addition to the Oil of
Urea in 2 to 1 Ethanol~Methanol Mixture
A 2 to 1 ethanol/methanol mixture was used
as a solvent for th- urea reactant because it
contains sufficient amounts of ethanol for
miscibility with th~ light Flsxicoker gas oil. A
nearly saturated solution Or 25.5 g ursa in 100 ml
o~ this solvent mixture was added to 45 ml (35.9g)
o~ LKGO with stirring. Stirring of the reaction
mixture was continued for 30 minutes. The urea
adduct wa~ then separated by filtration, washed
three times with 15 ~1 isooctane and dried. The dry
adduct wa then reacted with hot water. This
r~-ulted in th~ separation of 4.6g (11.6%) of oil
product havinq a composition similar to that of the
pr-vlous example.
: 200~4~4
- 52 -
Exam~le 6
Distillation of the ~-Olefin Plus n-Paraffin Mixture
Separ~ted From ~KQ. Via Urea Adductio~
The u-olefin and n-paraffin rich products
obtained via urea adduction ln the previous example~
wers combined and fractionally di~tilled at about 16
mm using an Oldershaw column having 20 theoretical
plates. The boiling ranges, amount~ and the main
components of the ~ractions obtained are shown in
Table II.
-- 53 --
zoo~s4
3 ~ .
L ~ O ¦ _ H _ ~
- ~ ~
~- ~ ~ I ~ o r O
U ~ S
~ I ~ ~ ~
- ~ æ ~ 0~ e
5 ~o I ~g '~ 5 E
5 ~ ~ ~ ~o
I O 1 0 ~ _
~Y~ ~ I 0' ~ ~ _ o
~il ., I , o ~ o~
. æ _
1 8 ~ _ "0 ,~ ~ Y
O ,~ ~ ~ ~ ~ ., ~ ~
",-, ~ ~ O - ,
æ o ~ ~: æ ,,, ~ ..
.~_ ~ ~ _ ~
200~49~
- 54 -
It is indicated by the data of Table II
that fractions rich in single carbon ~-olefin
components could be obtained At the end of the
distillation, the pressure was reduced to 0 1 mm to
obtain an additional fraction (59 8g) of the follow-
ing percentages of main components 18 97 Clg=;
30 ~0 Clg ; 9 71 Clg'; 15 41 Clg ; 2 38 C20= 4 28
C20 An analysis by packed column GC gave the
following carbon number distribution for this
fraction 57 3 C18 30 5 Clg; 8 0
Exam~?le 7
Separation of n-Decones Plu~ n-Decane
from a Clo Flexicoker Di~tillate Fraction
by the Addi~ L~ t_~c~Lk~y~ea Solu~io~
To 500 ml (401g) of an aqueous caustic
treated Clo Flexicoker naphtha fraction (bp 166 to
171 C) of 17% n-l-decene and 11 3% n-decane content,
a solution of 500 g urea in 2L of methanol was
added, with stirring The stirred mixture was
cooled to O'C using an ice-salt mixture and then
filtered by suction through a Buchner funnel The
urea adduct crystals were washed three times with
300 mL each of i-octane and dried in vacuo to
provide 399 g o~ dry intermediate
The adduct was added to 3600 mL of hot
(70 C) stirred water to liborate the n-decenes-
n-decane mixture which was succ-ssively extracted
~rom the water hy 500 ml n-hexan- and 500 mL ether
(The hydrocarbon extract wa~ a stable emulsion)
The combined extracts were washsd wlth 200 m~ water
and the solvent stripped o~ to provide 73 g of the
200~94
- 55 -
residual product- Cooling the filtrate of the
reaction mlxture to -20-C resulted mostly in urea
crystallization.
The composition of the product is illus-
trated by the capillary gas chromatogram of Figure
3. The quantitative GC data show the presence of
44.8% l-n-decene and 36.8% n-decane in the product.
Based on these data 48% of th- starting l-n-decene
was reco~ered from the starting Flexicoker
distillate. The remaining minor component~ of the
~eparated product mixtur- ar- mainly linear internal
decenes: ci--and trans-2-decene 3-, 4- amd 5-
decenes. 2-Methyl-l-nonene and 2-methyl-nonane were
also present in small quantities as indicated by the
Figure. The small amounts of l-n-nonene and
n-nonane present in the feed were al~o isolated with
the main n-Clo aliphatic hydrocarbon components.
The results indicate that the 1-n-olefin -
n-paraffin mixtures isolated via urea adduction
contain significant amount~ of linear internal
olefins of Type II and smaller amounts of monomethyl
branched terminal olefin~ of Type III. The presence
of these minor olefin components have no adverse
efrect~ on the propertie~ of the novel lubricants
d-rived fro~ these mixtures. Under appropriats
conditlon-, attractiv- lubricant~ having a unique
balanc- o~ properti-- can b- produced.
The separation o~ l-n-decene - n-decane
mixtures via urea adduction wa~ found to be highly
dependent on th~ a~ence o~ oxidative aging of the
Clo Flexicoker feed fraction. When an aged sample
200~494
- 56 -
of the sams distillate wa8 used ~or urea adduction,
the yield of l-n-decene - n-decane mixture was
reduced to about 10~ of th~ previously obtained
amount. Also, the parcentage of l-n-decene in the
mixture was somewhat ~maller than before: The
mixture of reduced yield contained 40.4% l-n-decene
and 44.8% n-decane.
Exa~e 8
OligomerizatiOn by BF3-C5~11H Of
Dodocenes Fractlon Derived From
U~aLa~ucts of Ligh~_Cok~r~Ga4 Oil
To 20g o~ the stirred dodecene~ distillate
fraction of Example 6, 3.1 g (0.02 mole) of 1:1 BF3
n-pentanol complex was added. The added complex
formed a separate bottom phase which wa~ well
dispersed in the hydrocarbon medium by the stirring
during the reaction. A slight exotherm, i.e.
warming of the reaction mixture to 25-C, was ob-
served. A GC analysis Or the mixture one hour after
the addition of this catalyst showed only about 4%
conversion of the reactants to dimers.
To form a more effective catalyst system,
B~3 gas W88 introduced into the reaction mixture
until saturation ~or 10 minute~ with continued
Jtirring. This re~ulted in a graater exotherm, up
-to 40-C. In another hour, ths compositlon Or the
mixture was agaln determln-d by GC. It wa~ found
that mo~t o~ the olefin component~ were reacted to
rorm dimers and trimers. According to packed GC the
upper product phase consi~ted of about 44~ Clo feed,
11% Or C20 dimer and 4S% C30 trimer. Capillary GC
200~49~
- 57 -
showed that 95~ of the unconverted C1o feed was
paraf~inic. The percentageg Or n-undecane and
n-dodecane were 18-6% and 69.1%, respectively~
After stirring the reaction mixture over the week-
end, all the ole~ins were reacted.
After the completion o~ the reaction, the
lower catalyst phase o~ the reaction mixture was
separated. It was 4 g, double the amount of the
initially added cataly~t.
~1- 9
Oligomerization of Dodecene~ from Urea
Adduct~ o~ LXG0 by BF~-~CH~)~C-CO~H
To 20 g of the stirred ice-watar cooled
dodecenes di~tillate fraction of Example 6, 3.4 g
(0.02 mole) of a 1:1 ~F3 neopentanoic acid was
added. A slight exotherm wa~ observed. After 1
hour, packed column GC analysis indicated the
presence o~ about 7% dimers and 3% trimers, plus
S.5% isomeric undecyl neopentanoate esters. After
overnight stirring, selective dimerization was
almost complete. About 35% dimers, 5% trimers and
4% esters were present. The remaining 56% C10
hydrocarbons contained 92% para~ins and only 8%
ole~ins according to capillary GC.
Sulrur speci~ic capillary GC showed that
most of th- sul~ur compounds o~ the C12 ~eed were
converted to high-r molocular weight species: The
prosence or a thiolestor among the neopentanoates
,
2~)0~494
- 58 -
and several sulfur compounds presumably thiethers in
The dimer range were indicated
ExamDle 10
Oligomerization of C10 to Clg n-Olefins
Derived from Urea Adducts by C2HsAlCl2
The di~tillat~ Sractions of Example 6 --
which were obtained by the fractional di9tillateion
Or the n-oleSin - n-paraSSin mixtures separatQd via
ur-a adduction Srom light Fl-xicoker gas oil in
Example 1 to 6 -- were u~ed a~ feed- for oligo~
merization in the presQnt example Th- composition
o~ these feeds is listed Table II of Example 6 The
C13-Cls reactant Sraction consisted of the combina-
tion of fractions VI and VII It contained 15%
C135, 21% C14' and 21% C1s~ n-oleSin~ The Cls
reactant was fraction VIII The C16 reactant was
fraction IX A~ the C17 reactant fraction XI was
employed Additionally, a mixture containing 43%
n-decene~ -- obtained in a similar manner from a C10
Flexicoker fr~ction -- was used to prepare n-decene
oligomers on a larger scale Ethylaluminum-
dichloride was employed as a liquid Friedel-Crafts
type catalyst in all the experiments of the example
Th- typical experiments were carried out
atmo~ph-ric pre~ur- in a nitrogen blanketed two
n-ck round botton Sla-k guipp-d with a cond-nser, a
magnetlc stirrer, a th-rmometer, a dropping ~unnel
and a hoating mantl~ n-Olefin - n-paraffin
reactant mixtures oS th~ composition shown in Table
III were added into th- reaction flask Their
~QO ~494
59
quantities ranged from 19 to 84 grams. The amount
of the ethylaluminum dichlorlde (EADC) catalyst
employed was 4 mole % (4 m EADC per 100 moles
olefin). The EADC wag added to the stirred olefin
as a 26% heptane 901ution at once at ambient
temperature. on the addition of the catalyst
solution an instantaneou~ exotharmic reaction
occurred. This usually resulted in a temperature
rise of the reaction ~ixture to 30-40-C. Once the
temperature stopped ri~ing, heat was applied to
raise the reaction temperature to 150-C and to keep
there for 1 hour. Therea~t~r, samples o~ the
reaction mixtures were analyzed.
The reaction mixture~ were allowed to cool
and then treated with excess water to hydrolyze the
catalyst. This usually resulted in the formation of
an emulsion which was treated with an about 30%
aqueous sodium hydroxide solution to break it. The
hazy organic phase was then filtered through a
Celite 512 to get clear liquid products. These
products were then stripped at reduced pressure
while heated to remove any volatile components, i.e.
hydrocarbons having les~ than 20 carbon atoms per
molecule.
The hydrocarbon reaction mixtures and
rQsidual oligom-ric product~ were analyzed by gas
chro~atography. The re~ults are shown by Table III.
,
2~)0~ 4
' ~ I ~
' ~
o ~ o 9~ o co ~r
~oe~ ~ ~C~o~oe~
o 0 ~ e
. ., ~ o
c~ ~ a - C O a~ ~ ~
O ~ E~ O ~ 3
~ ~, s ~il o ~ ~ ~ e o~ o
2 IV q~ ~ O O 1~ 0 O
O ~-- E~ CO O O ~S~ ~:
ol_ o ~ Or~ ~ e
O ~ o ~ O ~ ~ O
o ~ O "~ O ~ o
20~494
- 61 -
The data of the table show that the olefin
components o~ all thQ variou9 olefin paraffin
mixtures were oligomerized but to varying degrees.
The decenes of the Clo feed were convertsd to
oligomers of a broad molecular weight distribution,
ranging from C20 dimer8 to C60 hexamers. The main
products were trimers and tetramers. Only about
1.4~ unconverted dec~neg wero present in the
reaction mixtUrQ. In contrast, tha C13 to C17
olefins of the other four reaction mixtures were
mainly converted to dimQrs and trimers. From 24 to
37S of the ole~ins remained unconverted. The
composition of the re~idual product~ o~ thQ C13 to
C17 ole~lns on th~ rlght ~ide o~ the tabla shows
that the main components were dimars.
Exam~le 11
Properties of Polyole~in Lubricants Derived from
Mixtures of n-Olefins and n-Paraffins
The key properties o~ the polyolefin
lubricant~ were studied using the oligomeric pro-
ducts of the previous example. These properties,
the magnitude and temperature dependence of visco-
sity and low temperature flow, are similar for the
polyolafins and their hydrogenated isoparaffin
d~rivatives. Both propertie~ dapend on the mole-
cular weight, bran~hiness and n-al~yl sida chain
length.
The molecular w ight distribution of the
residual product~ wa~ furth-r studied by gel permea-
tion chromatography i.o~ GPC. (Product components
` 200~4~4
- 62 -
having more than 60 carbons per molecule could not
be determined by Gc) A~ it is shown by the data of
Table IV, the number average molecular weights of
the products (Mn) decreaged with the increasing
carbon number of monomers, indicating a definite
decrease in the degree of polymerization The
residual productg of d~cene and heptadecene oli-
gomerization had a relatively larger p~rcentage o f
trimers, thus a higher molecular weight, apparently
as a consequence of the prior removal of some o~ the
dimers (see Table III ot the previous example) The
prevalonce of dimers in product~ o~ higher ole~ins
in the C14 to C17 range i~ de~irable tor producing
isoparaffins in the C30-C40 range A combination of
~-olefin isomerization plus ~-oletin - internal
n-olefin codimerizatlon is a preferred route to such
dimers, e g
Cl4H2gcH~cH2-- > C7Hls-CH-CH-C7Hl5
CH2--CHcl 4H2 9
C7Hls-cH2-c-cH(cH3)cl4H29
C7H15
Th- molecular weight distribution of the
ros~dual product a~ detined by the ratio ot number
av-rag~ and w-ight averag- value~ (Mw/Mn) is
genorally broad Only tho pontadQcene oligomer,
trom which the monomor and parattin ware completely
removed, has a narrow molecular w-ight distribut~on
Whilo the pure tr$~-r derived rrOm l-n-decene has
ideal lubricant prop-rtie~ for many applications,
appropriate mixture~ ot oligom rs o~ broad molecular
20Q~49~
- 63 -
weight distri~utiOn in the dimer to hexamer range
possess balanced properties, particularly suited for
some applications.
6~~494
o ~"
.C ~ ~
c o ~, c ;:1 r~-
~ _
O ~ ~ I~
x c O ~r ~ r~
~11 U Y
_ O
'^ ''I -- ~ u~ u~ o
L ~C C C ~ O
~ ~1 î~
O ~ ~ ~
L s ~ ~0 01 ~ O ~
'O ~O ~ ~ ~r ~ ~ --
O ~ 3~ V) ~
~ ~9~ 1~ _ -- _ _ _ _ _
o r;
L -- ~1 ~ ~ 8
._ ~
~ ~ s ~ I
_ ~ aO~ _ 3
o ~ 0 1~ 0 ~0
L ~ ~ C
~
8 ~ O
1~1
200 :~494
- 65 -
As it i shown by Table IV, the residual
olefin oligomer9 exhibit varying kinematic viscosi-
ties at 40'C and lOO'C. These viscosities increase
in case of the oligomers of C13 to C16 olefins even
though their molecular wQights do not change much.
More importantly, the viscosity index of these
oligomers remains high indicat~ng that their vis-
cosity is relatively little affected by temperature
changes.
Table IV also shows th- pour points o~ the
re~idual products according to ASTM.Dg7-66. This is
a measure o~ low temperature properties; low pour
point indicates good low t~mp~ratur~ flow. The data
of the table indicate that with increasing chain
lengths of ths olefin feQds, the oligomer products
have higher pour points i.e. poorer low temperature
properties. The decene oligomer has a low pour
point. 80th its low temperature flow properties and
high temperature viscosity characteri~tics match
those o~ the oligomer similarly derived from pure
1-n-decene. With increasing monomer carbon numbers,
the low temperature lubricant propertie~ decline due
to the presence longer n-alkyl chains. However, at
the same time the viscosity becomes less dependent
on the temperature a~ indicated by the increased
vi~c08ity indices. The desired compromise between
hlgh pour polnt and high VI apparently depends on
th~ temper~ture o~ the de~ired lubricant applica-
tion.
2~0~94
- 66 -
Exam~le 12
Hydrogenation of Polydecene Derived from
~ecenes Separated from LKGO vl~_yrea Add~lction
Part of the polydecene residual product of
Example 10, is hydrogenated in the pre~ence of a
sulfided cobalt-nic~el catalyst under 1500 psi
hydrogen pressure in the 140 to 220'C range at a
temperature sufficient not only for adding hydrogen
to the olefinic unsaturation of the oligomeric feed
but for tho converoion to hydrog-n ~ulPide of the
sulfur compound impuritiee ~lgh-r temp-ratures are
avoided because they may re~ult in the sulfuration
of the isoparaffin product by the sul$ided catalyst
The crude isopara~fin product is purged in
vacuo with heating under nitrogen to remove all the
volatile by-product~, mostly paraffins, having less
than 25 carbon atoms per molecule
