Abstract: Disclosed herein are methods for preparing fluorided solid oxides by contacting an acidic fluorine-containing compound with an inorganic base to form an aqueous mixture having a pH of at least 4, followed by contacting a solid oxide with the aqueous mixture to produce the fluorided solid oxide. Also disclosed are methods for preparing fluorided solid oxides by contacting an acidic fluorine-containing compound with a solid oxide to produce a mixture, followed by contacting the mixture with a inorganic base to produce the fluorided solid oxide at a pH of at least about 4. The fluorided solid oxide can be used as an activator component in a catalyst system for the polymerization of olefins.

Abstract: A supported catalyst system includes a coprecipitated silica- and titania-containing support, alumoxane, and a metallocene. The supported catalyst system has a Ti content of at least 0.1 wt %.

Abstract: The present invention relates to a high activity olefin polymerization catalyst comprising a boron-containing silica support and the preparation thereof. This invention is characterized in that the support is heat treated in combination with a chemical treatment using a boron compound. The boron compound used in the chemical treatment of this invention is boron halide, preferably boron trichloride. The catalyst of this invention has the weight of boron comparing with the support is 0.5 to 0.7% and has the weight of the boron relative to the catalyst of 0.1 to 0.5%. The catalyst of this invention has chemical compositions comprising:—Boron 0.1-0.5% wt;—Titanium 4-6% wt;—Magnesium 2-6% wt;—Chloride 15-25% wt.

Abstract: A process for the preparation of organic cation tetrakis(Faryl) borate salts. The process includes preparation of intermediate, mono-hydrazine substituted (Faryl) compound, from (Faryl) compound using hydrazine at temperatures below 78° C. A stoichiometric excess of hydrazine to the (Faryl) compound to the (Faryl) compound is used. The process further includes the preparation of the organic cation tetrakis(Faryl) borate in ethereal medium.

Abstract: A novel process for reducing the molecular weight of nitrile rubber in the presence of specific catalyst systems containing the metathesis catalyst and also a specific addition of fluorine-containing boron compounds is provided.

Abstract: The present invention discloses a Ni-based catalyst useful in selective hydrogenation, comprising the following components supported on an alumina support: (a) 5.0 to 40.0 wt. % of metallic nickel or oxide(s) thereof; (b) 0.01 to 20.0 wt. % of at least one of molybdenum and tungsten, or oxide(s) thereof; (c) 0.01 to 10.0 wt. % of at least one rare earth element or oxide(s) thereof; (d) 0.01 to 2.0 wt. % of at least one metal from Group IA or Group IIA of the Periodic Table or oxide(s) thereof; (e) 0 to 15.0 wt. % of at least one selected from the group consisting of silicon, phosphorus, boron and fluorine, or oxide(s) thereof; and (f) 0 to 10.0 wt. % of at least one metal from Group IVB of the Periodic Table or oxide(s) thereof; with the percentages being based on the total weight of the catalyst. The catalyst is useful in the selective hydrogenation of a pyrolysis gasoline.

Abstract: Boron based catalysts and processes for preparing the catalysts are provided. The catalysts are suitable for the alkoxylation of alcohols using alkylene epoxides.

Abstract: Disclosed herein is a composition comprising a complex hydride and a borohydride catalyst wherein the borohydride catalyst comprises a BH4 group, and a group IV metal, a group V metal, or a combination of a group IV and a group V metal. Also disclosed herein are methods of making the composition.

Abstract: A carrier that may be used in the manufacture of an olefin epoxidation catalyst is provided that is prepared from a process involving depositing boron on the carrier and subsequently calcining the carrier. Also provided is an olefin epoxidation catalyst comprising a silver component deposited on such a calcined carrier. Also provided is a process for the epoxidation of an olefin employing such a catalyst and a process for producing a 1,2-diol, a 1,2-diol ether, or an alkanolamine employing the olefin oxide.

Abstract: Disclosed herein is a composition comprising a complex hydride and a borohydride catalyst wherein the borohydride catalyst comprises a BH4 group, and a group IV metal, a group V metal, or a combination of a group IV and a group V metal. Also disclosed herein are methods of making the composition.

Abstract: A catalyst body comprising a carrier and a catalyst layer containing an alkali metal and/or an alkaline earth metal, loaded on the carrier, which catalyst further contains a substance capable of reacting with the alkali metal and/or the alkaline earth metal, dominating over the reaction between the main components of the carrier and the alkali metal and/or the alkaline earth metal. With this catalyst body, the deterioration of the carrier by the alkali metal and/or the alkaline earth metal is prevented; therefore, the catalyst body can be used over a long period of time.

Abstract: A method for the preparation of a supported polymerisation catalyst system, comprises: (1) contacting together in a suitable solvent (a) a transition metal polymerisation talyst and (b) a cocatalyst, (2) contacting the mixture from step (1) with a porous support material, and (3) removing the solvent is characterised in that the molar ratio of cocatalyst to transition metal catalyst is <10:1. The preferred polymerisation catalysts are transition metal compounds in particular metallocene complexes. Premixing the catalyst components before addition to the support leads to certain advantages in particular a more facile method of preparation without any loss in activity.

Abstract: The present invention relates to a catalyst used for converting coal tar to diesel, the preparation method and use thereof The catalyst has a compound of iodine, an inorganic oxide matrix and the compound dispersed therein; or an inorganic oxide matrix and the compound dispersed therein together with a crystalline aluminosilicate zeolite, and relates to a method of coal tar converse to diesel in which at least one of the catalysts are used by dispersing an iodine compound in an inorganic oxide matrix.

Abstract: An ethylene oxide catalyst is provided which is essentially transition metal and rhenium free and which consists essentially of silver, alkali metal, sulfur and boron components on a support such as alumina, optionally with a fluorine or chlorine component.

Abstract: The present invention includes polymerization catalyst activator complexes which include at least Group 13 metals. The activator complexes of the invention are prepared, in general, by reacting a halogenated aryl Group 13 metal compound with a diol. The activator compound is represented in one aspect by: wherein each M1 is a Group 13 atom; each R3, R3′, R3″, and R3′″ group is independently selected from, for example, C1 to C30 alkyls, halogenated C1 to C30 alkyls, C6 to C60 halogenated aryls; with the proviso that at least one of R3, R3′, R3″, and R3′″ is a fluorinated C6 to C60 aryl group; R1 and R2 are independently selected from substituted or unsubstituted C1 to C100 hydrocarbylenes; R, when present, is a substituted or unsubstituted C30 hydrocarbylene; wherein when R is absent, R1 and R2 are bound together; and x is 0 or an integer from 1 to 100.

Abstract: A catalyst composition and process for preparing norbornene-type homopolymers or copolymers. The norbornene-type homopolymers or copolymers can be prepared using an in-situ catalyst composition including: (a) a transition metal compound of ML4, wherein M is a Group 10 metal and L is a neutral electron donor ligand; (b) a hydrocarbyl halogen containing a double bond or a triple bond; and (c) a salt of a non or weakly coordinative anion that can replace a halogen bonded to a metal. The catalyst composition is in a mixing state of components (a), (b), and (c), or in a mixing state of a reaction product of components (a) and (b) together with component (c).

Abstract: A catalyst activator particularly adapted for use in the activation of metal complexes of metals of Group 3-10 for polymerization of ethylenically unsaturated polymerizable monomers, especially olefins, comprising a neutral (Lewis acid) or charge separated (cation/anion pair) comprising a boron ligand containing a fluorinated organic group containing from 10 to 1000 non-hydrogen atoms.

Abstract: A method for feeding a boron compound, which comprises feeding at least one boron compound selected from (1) to (3) described below in the state suspended or slurried in a solvent continuously to a reactor; a boron compound in the form of fine particles being one or more boron compounds selected from (1) to (3) described below and having a maximum particle diameter of 50 &mgr;m or less; a catalyst component for olefin polymerization consisting of said boron compound in the form of fine particles; a method for producing a boron compound in the form of fine particles which comprises dissolving one or more boron compounds selected from (1) to (3) described below in an aromatic hydrocarbon solvent and then precipitating in an aliphatic hydrocarbon solvent; and a method for producing a boron compound in the form of fine particles which comprises pulverizing one or more boron compounds selected from (1) to (3) described below so that their maximum particle diameter is 50 &mgr;m or less.

Abstract: A method for preparing polybutadiene having controlled molecular weight and high 1,4-cis content over 95% in the presence of a diethylzinc compound as a cocatalyst (i.e., alkylating agent) and molecular-weight-controlling agent, in which the molecular weight of the polybutadiene is controlled by variating the added amount of the diethylzinc compound without deterioration of 1,4-cis content nor polymerization yield, thus guaranteeing the optimum processability and physical properties of polymer according to the use purpose.

Abstract: A catalyst containing a sulfide phase comprising (a) sulfur (b) and at least one element A selected form group IIIB, including the lanthanides and actinides, group IVB and group VB, and optionally (c) at least one element B selected from group VIIB and group VIII and mixtures thereof, is suitable for use in, for example, hydrorefining or hydroconversion. Sulfur is present in the catalyst at a quantity higher than the quantity corresponding to 40% of the stoichiometric quantity of sulfur in the sulfide compounds of elements from groups MB, IVB, VB, VIIB and VIII. The catalyst also, optionally, comprises at least one porous amorphous or low crystallinity type matrix.

Abstract: This description addresses a process for the preparation of polyolefins from one or more olefinic monomers comprising combining under polymerization conditions said olefins with the product of combining i) an organometallic catalyst compound and ii) a cocatalyst complex comprising a trialkylsilyl-substituted carbenium cation and a suitable noncoordinating or weakly coordinating anion. These complexes exhibit good solubility in aliphatic solvents such that use in aliphatic solution based polymerization reaction processes can be conducted without the use of aromatic solvents or co-solvents and without the need for slurry means of introduction into chemical reaction environments. High number-average molecular weight polymers and copolymers at high rates of productivity were observed from the use of metallocene catalysts complexes when activated with [(3,5-Et3Si)2Ph)3C]+ [(C6F5) B]− and used in a hexane-based solution polymerization.

Abstract: Sulfided catalysts produced by sulfurizing supported catalysts containing at least one element selected from group IIIB, including the lanthanides and actinides, group IVB and group VB, wherein the catalyst is brought into contact with at least one source of elemental sulfur e.g. flowers of sulfur in an atmosphere of at least one reducing gas other than hydrogen e.g. carbon monoxide. The catalyst is suitable for converting hydrocarbon-containing feeds, such as hydrocracking and hydrotreatment.

Abstract: The invention pertains to a process for preparing an activated catalyst, to the activated catalyst composition and the use thereof in the conversion of hydrocarbon feedstocks, such as isomerisation. The catalyst composition comprising a Group VIII noble metal and a hydrocarbon-substituted aluminum compound on an alumina carrier is activated by contacting it with an inert gas in the absence of hydrogen at a temperature above 400° C., wherein at least when the hydrocarbon-substituted aluminum compound is a non-halide hydrocarbon-substituted aluminum compound, the catalyst composition is contacted with a halogen-containing gas either prior to the treatment with the inert gas or during the treatment with the inert gas, and subsequently cooling down the activated catalyst to ambient temperature in an inert gas optionally containing hydrogen or containing, at a temperature below 400° C.

Abstract: A supported Lewis acid catalyst system effective for hydrocarbon conversion reactions including cationic polymerization, alkylation, isomerization and cracking reactions and comprising at least one Lewis acid immobilized on an anhydrous dihalide of Cd, Fe, Co, Ni, Mn or Mg is disclosed.

Abstract: The invention concerns a process for sulphurizing supported catalysts containing at least one element selected from group IIIB, including the lanthanides and actinides, group IVB, group VB and group VIB, said process being characterized in that said catalyst is pre-reduced with at least one reducing gas other than hydrogen before sulphurizing said catalyst. The invention also concerns the sulfide catalysts obtained by the process of the present invention as well as the use of the sulfide catalyst in a process for hydrocracking and hydrotreatment of hydrocarbon-containing feeds.

Abstract: Bulky noncoordinating anions that are surprisingly stable under olefin polymerization conditions such that olefin polymers can be prepared with unexpectedly high molecular weights at high catalyst efficiencies. Thus the invention is directed to an olefin polymerization process comprising contacting under polymerization conditions one or more ethylenically unsaturated monomers with a catalyst composition comprising at least one organometallic transition metal compound activated to a cationic state and a stabilizing, compatible non-coordinating Group 13 anionic complex having halogenated aromatic ligands in an essentially tetrahedral structure wherein the aromatic groups are polycyclic fused or pendant aromatic rings.

Abstract: The invention concerns a process for sulphurising supported catalysts containing at least one element selected from group IIIB, including the lanthanides and actinides, group IVB and group VB, said process being characterized in that said catalyst is sulphurised using a mixture containing at least one source of elemental sulphur and at least one source of carbon in an autogenous or inert atmosphere. Also disclosed are sulphurised catalysts obtained by the process of the invention, the use of the catalysts in processes for hydrocracking and hydrotreatment of hydrocarbon-containing feeds.

Abstract: Ionic catalyst compositions can be prepared by combining two components. The first component is a bis(cyclopentadienyl) Group IV-B metal complex containing at least one ligand which will combine irreversibly with the second component or at least a portion thereof such as a cation portion thereof. The second component comprises a cation which will irrevesibly react with at least one ligand on the Group IV-B metal complex and a non-coordinating anion. The combination of the two components produces an ionic catalyst composition comprising a cationic bis(cyclopentadienyl) Group IV-B metal complex which has a formal coordination number of 3 and a 4+ valence charge and the aforementioned non-coordinating anion.

Abstract: The invention is a polymerization process for ethylene copolymers having a density less than 0.915 comprising contacting ethylene, one or more &agr;-olefin monomer, and optionally one or more diene monomer, with a catalyst composition comprising the reaction product of at least one organometallic Group 4 metallocene compound derived from a bridged, fused-ring ligand containing biscyclopentadienyl hafnocene, said bridge being a substituted or unsubstituted carbon or silicon atom connecting the biscyclopentadienyl ligands, and a salt of a Group 13 element anionic complex having halogenated aromatic ligands in an essentially tetrahedral structure wherein the aromatic groups are polycyclic fused or pendant aromatic rings. The process is particularly suitable for the preparation of high comonomer content and high molecular weight ethylene-&agr;-olefin plastomers and ethylene-propylene or ethylene-propylene-diene monomer elastomers.

Abstract: The invention relates to a process of activating a supported acid catalyst, and consists in the conversion of Lewis acid-type acid sites which are deposited on a solid substrate into activated acid sites in a non-oxydizing acid medium. The catalyst is exposed to a phase of activation in a medium containing a holohydric acid or a halohydric acid precursor, in the presence of at least one preferably parafinic hydrocarbon or hydrocarbon derivative, at a temperature greater than 20° and preferably between 100° C. and 250° C., and at a pressure of between 105 and 50,106 Pa, for a length of time sufficient to ensure conversion into activated acid sites.

Abstract: Ionic compounds represented by general formula (I), method of their production, olefin polymerization catalyst components, and olefin polymerization catalysts containing the components are provided.?M(R.sup.1).sub.k (R.sup.2).sub.1 (R.sup.3).sub.m (R.sup.4 -L).sub.n !.sup.- ?D!.sup.+ (I)(wherein, M is an element belonging to the Group 13; R.sup.1, R.sup.2 and R.sup.3 are pentafluorophenyl, etc., R.sup.4 is a substituted phenylene group, etc., k, l and m being each 0 or an integer of 1 to 3, and n being an integer of 1 to 4 such that k+l+m+n=4; L is trichlorosilyl, methyldichlorosilyl, dimethylchlorosilyl group, etc.; and D is a monovalent cation).

Abstract: This invention includes catalysts comprising rhenium (atomic number 75), nickel, cobalt, boron and copper and/or ruthenium impregnated on a support material and a process for preparing said catalyst, said process comprising (i) impregnating a mixture of metals comprising rhenium, cobalt, copper and/or ruthenium, boron and nickel on a support material selected from the group consisting of alpha-alumina, silica, silica-alumina, kieselguhrs or diatomaceous earths, and silica-titanias; and (ii) activating said catalyst by heating the catalyst in the presence of hydrogen at an effective temperature preferably in the range of about 150.degree. C. to about 500.degree. C. for a sufficient period preferably of from about 30 minutes to about 6 hours.

Abstract: The present invention includes related methods and uses, including composition comprising the polymer derived from a monomer having the formula:H.sub.2 C.dbd.CHR; (1)and optionally at least one monomer selected from the group consisting of monomers having the formula:R.sup.1 HC.dbd.CHR.sup.2 ; and (2)H.sub.2 C.dbd.CR.sup.2 R.sup.3 (3)wherein R is a hydrocarbon or substituted hydrocarbon having from 2 to 22 carbon atoms, and R.sup.1, R.sup.2 and R.sup.3 are the same or different hydrocarbons or substituted hydrocarbons having 1 to 22 carbon atoms. R is preferably an ethyl group (--CH.sub.2 CH.sub.3) and R.sup.1, R.sup.2 and R.sup.3 are preferably methyl groups (--CH.sub.3).

Abstract: A supported Lewis acid catalyst, which comprises an inorganic oxide substrate having immobilized thereon at least one Lewis acid and a modifying agent containing at least one functional moiety capable of reacting with surface hydroxyl groups originally present on said substrate and which is effective as a catalyst for hydrocarbon conversion reactions including cationic polymerization, alkylation, isomerization and cracking reactions is disclosed.

Abstract: Essentially nitrate-free catalyst for the wash-and-wear finishing of textiles with formaldehyde-free crosslinkers, comprising magnesium, tetrafluoroborate, chloride and sulfate ions in the molar weight ratios of(a) Mg.sup.2+ : BF.sub.4.sup.- =1:0.1 to 1:4,(b) Mg.sup.2+ : Cl.sup.- =1:1.7 to 1:15 and(c) SO.sub.4.sup.2- : Cl.sup.- =1:0.2 to 1:4.

Abstract: A catalytic composite of a refractory inorganic oxide whose bound surface hydroxyl group has reacted with a Friedel-Crafts type metal halide and whose acidity has been modified by the deposition of a monovalent metal cation, especially an alkali metal cation, or alkaline earth metal cation shows superior selectivity and a significantly decreased cracking tendency relative to similar catalysts without the monovalent metal or alkaline earth metal cation. The resulting alkylate from an isobutane-butene feedstock shows a substantial increase in research octane number relative to the alkylate formed by a similar catalyst which has not been so modified by an alkali or alkaline earth metal cation.

Abstract: The present invention concerns a catalyst comprising a porous organic or mineral support, preferably silica, and an acidic phase containing B(OSO.sub.2 CF.sub.3).sub.3 and at least one acid selected from the group formed by sulphuric acid (H.sub.2 SO.sub.4) and trifluoromethane sulphonic acid (CF.sub.3 SO.sub.3 H), the support having been impregnated by said acidic phase, said catalyst being such that it is constituted essentially by particles with an average diameter of between 0.1 and 150 .mu.m, such that the support, prior to its impregnation with said acidic phase, has a total pore volume of between 0.5 and 6 cm.sup.3 per gram and said catalyst being characterized in that said acidic phase contains:between 0.1 and 70% by weight of B(OSO.sub.2 CF.sub.3).sub.3 ;between 0 and 90% by weight of H.sub.2 SO.sub.4 ;between 0 and 90% by weight of CF.sub.3 SO.sub.3 H.

Abstract: A process for the synthesis of a catalyst for the polymerization of carbon monoxide and at least one olefin which comprises treating a mixture of a compound of palladium, such as tetrakis(acetonitrile) palladium, and a Lewis acid anion, such as a fluoride of a metal selected from Group III to Group V of the Periodic Table (e.g., boron trifluoride), with carbon monoxide and an olefin followed by reaction of the resulting composition with a bidentate ligand reagent, such as a 1,3-bis(diphenyl-phosphino) alkane (e.g., 1,3-bis(diphenyl-phosphino) propane).

Abstract: A supported Lewis acid catalyst system for catalyzing hydrocarbon conversion reactions including cationic polymerization, alkylation, isomerization and cracking reactions is disclosed, wherein the catalyst system comprises an inorganic oxide support having immobilized thereon at least one relatively strong Lewis acid and at least one relatively weak Lewis acid.

Abstract: A living carbocationic catalyst composition comprising an initiator of a tertiary alkyl halide, a tertiary aralkyl halide or polymeric halide a co-initiator of a methylaluminum or methylboron compound, and a solvent medium with a dielectric constant between 2.5 and 7 is used to produce narrow molecular weight distribution polymers particularly isobutylene polymers.

Abstract: A catalyst useful in the disproportionation of alkanes is provided comprising an acid component having the formula HB(OSO.sub.2 CF.sub.3).sub.4 and a support. A method for the disproportionation of C.sub.4 -C.sub.16 alkanes employing the catalyst is also provided.

Abstract: A method of enhancing the activity of a catalyst for the hydroprocessing of hydrocarbons, comprising:(a) applying a modifying element dissolved in a solvent onto the surface of a finished catalyst;(b) drying said modified finished catalyst to remove all free solvent from said catalyst;(c) optionally, heating said dried, modified finished finished catalyst at a temperature of about 120.degree. C. to about 1000.degree. C. at a rate of 1.degree.-20.degree. C. per minute, and holding said dried catalyst at a temperature of about 120.degree. C. to about 1000.degree. C. up to 48 hours to provide an enhanced finished catalyst; and(d) recovering said enhanced finished catalyst.

Abstract: A chloride-free catalyst for wash-and-wear finishing textiles with formaldehyde-free crosslinking agents contains magnesium and fluoroborate ions in a ratio of from 1:0.1 to 1:4 and guarantees odorless results.

Abstract: The invention provides a catalyst complex for promoting alkylation of an isoparaffin with an olefin, said catalyst complex comprising the reaction product of Lewis acid and at least one fluorophosphoric acid; and, additionally, excess Lewis acid in concentration of from about 10 ppm (weight) to about 10000 ppm by weight of the total isoparaffin and olefin feed. The invention further provides a process for the alkylation of an isoparaffin with an olefin by contacting a mixture of isoparaffin and olefin with the catalyst complex of the invention.

Abstract: The invention relates to a process for the preparation and activation of a catalyst, comprising a stage of fabricating a support consisting at least in part of at least one refractory oxide mineral, a stage of depositing on the support at least one metal from the platinum group, and a stage intended for forming on the support at least two metal halides of the Lewis acid type. Between the deposition of the metal halides of the Lewis acid type and the utilization of the catalyst in the reactor, the catalyst is subjected to an activation stage by being maintained in an acidic and nonoxidizing or reducing medium at a temperature between 300.degree. and 475.degree. C. so that its final content of a promoter metal of the zirconium, molybdenum tungsten or titanium type ranges from 0.15 to 1 percent, based on the weight of the support.

Abstract: The present invention provides a catalyst for hydrogenation of aromatic compounds, which comprises a hydrophilic support material; and a stationary aqueous acid phase supported by the hydrophilic support material, the aqueous acid having a transition metal catalyst dissolved therein. Preferably, the solid hydrophilic support material is an acidic material, such as an acid-treated clay. The foregoing catalyst is particularly useful in hydrogenating aromatic hydrocarbons.

Abstract: Disclosed herein are boron trifluoride etherate complexes in which the ether of the complex has at least one tertiary carbon bonded to an ether oxygen. The etherates are useful for polymerizing a one-olefin or mixtures thereof, preferably comprising isobutylene, whereby the resulting polymer contains a high percentage (80-100%) vinylidene character.

Abstract: A process for the preparation of carboxylic acids or of esters thereof by contacting an olefinically unsaturated compound with CO in the presence of water or an alcohol, respectively, and of a catalytic system prepared by combining a ruthenium compound and a compound having a non-coordinating anion of an acid with a pK.sub.a below 0.5; compositions comprising a ruthenium compound and a salt having a non-coordinating anion of an acid with a pK.sub.a below 0.5 are novel.

Abstract: This invention relates to a process for hardening a curable normally liquid hydrocarbon compound optionally substituted with an alkyloxy, ester aldehyde, amido, halo, sulfonate, sulfate, sulfite, mercapto or nitro group and containing at least one functional radical selected from the group of ##STR1## and--(X)C.dbd.C(Z)--Y--(CH.sub.2)--wherein Y is --O--, --S-- or --NH-- and X and Z are each independently hydrogen, alkylene having from 1 to 20 carbon atoms, aryl or a mixture thereof, which process comprises contacting said liquid for less than one minute with a hardening amount of a volatilized hard Lewis acid under anhydrous conditions and at a hardening temperature below the deformation temperature of any substrate material which may be used to support said liquid.

Abstract: A process for the manufacture of an olefin oligomer, comprising the steps of polymerizing an olefin monomer in the presence of boron trifluoride and a boron trifluoride-alcohol complex as catalysts, to prepare a first oligomerization product, and then carrying out one of following steps (a) to (c): (a) removing boron trifluoride from the above first product by (i) placing the product under a reduced pressure, (ii) blowing an inert gas into the product, or (iii) heating the product at a relatively low temperature, to thereby prepare a second oligomerization product, and then subjecting the second product to a precipitation treatment to separate the boron trifluoride-alcohol complex therefrom, (b) heating the above first product at a relatively elevated temperature to recover boron trifluoride, or (c) centrifuging the above first product to recover the boron trifluoride-alcohol complex. These steps allow the catalysts to be recovered while maintaining the activity thereof at a desired level.