CA2004494A1 - Multistep process for the manufacture of novel polyolefin lubricants from sulfur containing thermally cracked petroleum residua - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A multistep process is disclosed for the manufacture of synthetic lubricants from the C8 to C24 linear olefin components of below liquid fuel value petroleum distillate fractions derived via the high temperature thermal cracking of petroleum residua. Such feeds contain major amounts of 1-n-olefins, n-paraffins and greater than 0.1%
concentration of sulfur mostly in the form aromatic, thiophene type sulfur compounds.

In the first step of the present process such feeds are enriched in the straight chain aliphatic hydrocarbon components by one or more separation processes, preferably via urea adduction or by crystallization. In the second step, the olefin components are oligomerized to sulfur con-taining C30 to C60 polyolefins, preferably in the presence of BF3 complex catalysts. In the third step, the polyolefins are hydrogenated to novel isoparaffin lubricants in the presence of sulfur resistant catalysts, preferably transition metal sulfides.

Description

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.

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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 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:

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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 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 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 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 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.

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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~

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 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~

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.

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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 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 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.

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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 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 ~-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~ .

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 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 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 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~

~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%

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 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 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 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~ .

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~

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 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~

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 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~ .

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~

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 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~

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~

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~

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~

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 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 Cl6 6 23 6 34 0 98 Clg 1 25 1 98 0 63 c2o 0 64 1 20 0 56 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~

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 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.

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~

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 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 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~

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 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 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 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 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 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~

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 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 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

Claims (12)

1. A multistep process for the manufac-ture of polyolefin lubricants, derived mostly from C8 to C24 linear olefin components of coker distil-late fractions containing more than 0.1% sulfur which are produced by the high temperature thermal cracking of petroleum residua, comprising the following three steps:

a) enrichment of coker distillate feed in l-n-olefin and n-paraffin components by one or more separation processes including urea adduction or crystallization, b) oligomerization of the C8 to C28 olefin components of an enriched coker distillate fraction to produce sulfur containing C30 to C60 polyolefins, c) hydrogenation of sulfur containing polyolefins to isoparaffins with the simultaneous removal of the sulfur

2. A process according to Claim 1 wherein siad separation process is carried out via urea adduction or crystallization.

3. A process according to Claim 1, wherein said coker distillate feed fractions, derived from the thermal cracking of petroleum residua, contain l-n-olefins and as the main type of olefin components, the percentage of Type I olefins being more than 30% of the total olefins, and organic sulfur compounds are present in concentra-tions exceeding 0.5% sulfur equivalent

4 The process according to Claim 1 wherein the enrichment of the coker distillate in l-n-olefins and n-paraffins includes their separa-tion via urea adducts.

5. The process according to Claim 1 wherein the enrichment of the coker distillate in 1-n-olefins and n-paraffins includes the crystalli-zation of these components

6. The process according to Claim 1 wherein the oligomerization of C8 to C24 olefin components of an enriched coker distillate fraction is carried out in the presence of a cationic cata-lyst.

7. The process according to Claim 1 wherein the hydrogenation of the sulfur containing polyolefins is carried out in the presence of transition metal sulfide catalysts.

8. A multistep process for the manufac-ture of polyolefin lubricants, derived mostly from C8 to C24 linear olefin components of coker distillate fractions containing more than 0.5%
sulfur and l-n-olefins as the major type of olefins which are produced by the high temperature thermal cracking of petroleum residua, comprising the following three steps of:

a) enrichment of coker distillate feed in l-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 Or an enriched had coker distillate fraction in the presence of a Friedel-Crafts catalyst to produce sulfur containing C30 to C60 polyolefins, c) hydrogenation of the sulfur containing polyolefins to is oparaffins with the simultaneous removal of sulfur in the presence of transition metal sulfide catalysts.

9. The process according to Claim 8, wherein the oligomerization of the C8 to C24 olefin components is carried out in the presence of a complex catalyst.

10. Novel polyolefin type synthetic lubri-cant compositions derived from C8 to C24 linear olefins wherein said olefins contain l-n-olefin as major components, and internal n-olefins and methyl branched components as minor components, and said olefin mixture is separated together with major amounts of n-paraffins from a coker distillate feed containing l-n-olfins and n-paraffins as major components, and oligomerized in the presence of acid catalysts to a polyolefin comprising 2 to 6 monomer units, said polyolerln product mixture containing n-paraffrina thwn being hydrogonated to provide a mixture of isoparaffin lubricants and unconverted n-paraffins from which the paraffins are then removed preferably by digtlllation, or said mixture of n-olefins and n-paraffins is first subjected to distillation to remove the paraffins and then hydrogenated to provide the novel isoparaffin lubricants.

11. The lubricant compositions according to Claim 10 which are derived mainly from C9 to C13 l-n-oledins.

12. The lubricant compositions according to Claim 10 wherein said polyolefin product mixture containing n-paraffins is at first hydrogenated to give an isoparaffin n-paraffin mixture from which the n-paraffins and other volatile components are then removed by distillation.