CA2140369A1 - Improved lewis acid promoted transition alumina catalysts and isoparaffin alkylation processes using those catalysts - Google Patents

Abstract

This invention is directed to a catalyst system for use in the alkylation of isoparaffin with olefins. More specifically, this invention is directed to an improved catalyst system containing specified amounts of water and a component of that system com-prising certain transition aluminas promoted with a Lewis acid (preferably BF3). In addition, this invention is a catalytic pro-cess for the alkylation of isoparaffin with olefins. The catalyst component is produced by contacting the transition alumina with the Lewis acid at relatively low temperatures. The catalyst system comprises that component and an additional amount of free Lewis acid. The process entails isoparaffin alkylation with olefins using the catalyst component and its allied catalyst system.

Description

2~4~g~
W094/02~3 PCT/US93/06712 r~v~ .~WIS A~Tn PRO~IO~ T~ANSITION ~rT~T~A
~A~AT.ysTs AND ISOP~AFFIN AT,~yT.~ION PROCESSES USING
THOS~ ~AT~TYSTS

Field of the Invention This invention is to: a) a catalyst system, b) an improved catalyst system cont~;ning specified amounts of water, c) a compo~nt of that system comprising certain transition aluminas promoted with a Lewis acid (preferably BF3), and d) a catalytic process for the alkylation of isoparaffin with olefins. The catalyst component is proAt~ by contacting the transition alumina with the Lewis acid at relatively low temperatures. The catalyst system comprises that component and an additional amount of free Lewis acid.
The process entails olefin/isoparaffin alkylation using the catalyst comr~n~nt and its allied catalyst system.

BACKGROUND OF ~F I NV~:N'l'lON
The preparation of high octane bl~n~i ng components for motor fuels using strong acid alkylation processes (notably where the acid is hydrofluoric acid or sulfuric acid) is well-known. Alkylation is the reaction in which an alkyl group is added to an organic molecule, typically an aromatic or olefinic molecule.
For production of gasoline blenA;~g stocks, the reaction is beiween an isoparaffin and an olefin.
Alkylation pro~C~es have been in wide use since World War II when high octane gasolines were needed to 214036g . ~
W094/02~3 PCT/US93/06712 ~ -2-satisfy demands from high compression ratio or supercharged aircraft engines. The early alkylation units were built in conjunction with fluid catalytic cracking units to take advantage of the light end by-products of the cracking units: isoparaffins andolefins. Fluidized catalytic cracking units still constitute the major source of feedstocks for gasoline alkylation units. In spite of the mature state of strong acid alkylation technology, existing problems with the hydrofluoric and sulfuric acid technologies continue to be severe: disposal of the used acid, unintentional emission of the acids during use or storage, substantial corrosivity of the acid catalyst systems, and other environmental concPrns.
Although a practical alkylation process using solid acid catalysts having little or no co~o~ive components has long been a goal, commercially viable processes do not exist.
The open literature shows several systems used to alkylate various hydrocarbon feedstocks.
The American Oil Company obtained a series of patents in the mid-1950's on alkylation pro~e-cr^c involving C2-CI2 (preferably C2 or C3) olefins and C4-C8 isoparaffins. The catalysts used were BF3-treated solids and the catalyst system (as used in the alkylation process) also cont~; nP~ free BF3. A summary of those patents is found in the following list:
BF3-Treated Catalyst Patçnt No. Inventor (with free BF3) 2,804,491 May et al. SiO2 stabilized Al2O3 (10%-60% by weight BF3) 2,824,146 Kelly et al. metal pyrophosphate hydrate 2,824,150 Knight et al. metal sulfate hydrate 2~ 4~3~
.

W094/02~3 PCT/US93/06712 2,824,151 Kelly et al. metal stannate hydrate 2,824,152 Knight et al. metal silicate hydrate 2,824,153 Kelly et al. metal orthophosphate hydrate 2,824,154 Knight et al. metal tripolyphosphate hydrate 2,824,155 Knight et al. metal pyroarsenate hydrate 2,824,156 Kelly et al. Co or Mg arsenate hydrate 2,824,157 Knight et al. Co, Al, or Ni borate hydrate 2,824,158 Kelly et al. metal pyroantimonate hydrate salt 2,824,159 Kelly et al. Co or Fe molybdate hydrate 2,824,160 Knight et al. Al, Co, or Ni tungstate hydrate 2,824,161 Knight et al. LG~O~U~YX~iC acid hydrate or Ni or Cd borotungstate hydrate 2,824,162 Knight et al. phosphomolybdic acid hydrate 2,945,907 Knight et al. solid gel alumina (5%-100% by weight of Zn or Cu fluoborate, preferably anhydrous) May be supported on Al203 None of the above patents disclose a process for alkylating olefins and isoparaffins using neat alumina treated with BF3.
Related catalysts have been used to oligomerize olefins. U.S. Patent No. 2,748,090 to 21~36~ ~
W094/02~3 ~~ PCT/US93/06712 Watkins suggests the use of a catalyst made up of a Group VIII metal (preferably nickel), a phosphoric acid (preferably cont~; ni ng phosphorus pentox;~P), all placed on an alumina adsorbent, and pretreated with BF3. Alkylation of aromatics is suggested.
U.S. Patent No. 2,976,338 to Thomas suggests a polymerization catalyst comprising a complex of BF3 or H3PO4 optionally on an adsorbent (such as activated carbon) or a molecular sieve optionally contAi~ing potassium acid fluoride.
Certain references suggest the use of alumina-cont~;n;ng catalysts for alkylation of aromatic compounds. U.S. Patent No. 3,068,301 to Hervert et al.
suggests a catalyst for alkylating aromatics using "olefin-acting compounds". The catalyst is a solid, silica-stabilized alumina contAin;ng up to 10% SiO2, all of which has been modified with up to 100% by weight of BF3. None of these prior references suggest either the process or the material used in the processes as is disclosed here.
Other BF3-treated aluminas are known. For instance, U.S. Patent No. 3,114,785 to Hervert et al.
suggests the use of a BF3-modified, substantially anhydrous alumina to shift the double bond of 1-butene to produce 2-butene. The preferred alumina is substantially anhydrous gamma-alumina, eta-alumina, or theta-alumina. The various al~r; n~ will adsorb or complex with up to about 19% by weight fluorine ~PpPn~ing upon the type of alumina and the temperature of treatment. The all~ri~c are treated with BF3 at elevated temperatures. Hervert et al. does not suggest using these catalysts in alkylation reactions.
In addition, TJ~So P~tent No. 3,131,~0 to Hervert et al. describes a process for the alkylation 21~6~-of aromatic compounds which utilizes a catalyst comprising boron trifluoride and boron trifluoride modified, substantially anhydrous alumina. This reference teaches that the activity of the catalyst is maintained by introducing water in an amount up to 400 parts per million molal and boron trifluoride in an amount up to 3200 parts per million molal in the hydrocarbon feed. Although this reference teaches that the modification of the alumina with the boron trifluoride gas may be carried out in a range between room temperature and up to about 300C, it is noted that this step is highly exothermic. For example, when the modification is carried out at room temperature, a temperature wave will travel through the alumina causing the temperature to increase up to about 150C
or more.
In U.S. Patent No. 4,407,731 to Imai, a high surface area metal oxide such as alumina (particularly gamma-alumina, eta-alumina, theta-alumina, silica, or a silica-alumina) is used as a base or ~u~po~L for BF3.
The BF3 treated metal oxide is used for generic oligomerization and alkylation reactions. The metal oxide is treated in a complicated fashion prior to being treated with BF3. The first step entails treating the metal oxide with an acid solution and with a basic aqueous solution. The support is washed with an aqueous decomposable salt such as ammonium nitrate.
The support is washed using deionized H20 until the wash water shows no alkali or alkaline earth metal cations in the filtrate. The support is dried and calcined. The disclosure suggests generically that BF3 is then introduced to the treated metal oxide ~u~orL.
The examples show introduction of the BF3 at elevated temperatures, e.g, 300C or 350C.

2 1 ~

Similarly, U.S. Patent No. 4,427,791 to Miale et al. suggests the enhancement of the acid catalytic activity of inorganic oxide materials (such as alumina or gallia) by contactingL~he material with ammonium fluoride or boron fluorlde, contacting the treated inorganic oxide with an aqueous ammonium hydroxide or salt solution, and calcining the resulting material.
The inorganic oxides treated in this way are said to exhibit enhanced Bronsted acidity and, therefore, are said to have improved acid activity towards the catalysis of numerous reactions (such as alkylation and isomerization of various hydrocarbon compounds). A
specific suggested use for the treated inorganic oxide is as a matrix or support for various zeolite materials ultimately used in acid catalyzed organic compound conversion proceR-^c.
U.S. Patent No. 4,751,341 to Rodewald shows a process for treating a ZSM-5 type zeolite with BF3 to reduce its pore size, enhance its shape selectivity, and increase its activity towards the reaction of oligomerizing olefins. The patent also suggests using these materials for alkylation of aromatic compounds.
Certain Soviet publications suggest the use of Al203 catalysts for alkylation processes. Benzene alkylation using those catalysts (with 3 ppm to 5 ppm water and periodic additions of BF3) is shown in Yagubov, Kh. M. et al., Azerb. Khim. Zh., 1984, (5) p.
58. Similarly, Kozorezov, Yu and Levitskii, E.A., Zh.
Print. Khim. (Lenin~rad), 1984, 57 (12), p. 2681, show the use of alumina which has been heated at relatively high temperatures and modified with BF3 at 100C.
There are no indications that BF3 is maintained in excess. Isobutane alkylation using Al203/BF3 catalysts is suggested in Neftekhimiya, 1977, 17 (3), p. 396;
1979, 19 (3), p. 385. The olefin is ethylene. There 214035~
W094/02~3 PCT/US93/06712 is no indication that BF3 is maint~;ne~ in excess during the reaction. The crystalline form of the alumina is not described.
U.S. Patent No. 4,918,255 to Chou et al.
suggests a process for the alkylation of isoparaffins and olefins using a composite described as "comprising a Lewis acid and a large pore zeolite and/or a non-zeolitic inorganic oxide". The process disclosed requires isomerization of the olefin feed to reduce substantially the content of alpha-olefin and further suggests that water addition to the alkylation process improves the operation of the process. The best Research Octane Number (RON) product made using the inorganic oxides (in particular SiO2) is shown by Table 6 therein to be 94Ø
Similarly, PCT published applications WO
90/00533 and 90/00534 (which are based in part on the U.S. patent to Chou et al. noted above) suggest the same process as does Chou et al. WO 90/00534 is specific to a process using boron trifluoride-treated inorganic oxides including "alumina, silica, boria, oxides of phosphorus, titanium oxide, zirconium oxide, chromia, zinc oxide, magnesia, calcium oxide, silica-alumina-zirconia, chromia-alumina, alumina-boria, silica-zirconia, and the various naturally occurring inorganic oxides of various states of purity such as bauxite, clay and diatomaceous earth". Of special note is the statement that the "preferred inorganic oxides are amorphous silicon dioxide and aluminum oxide". The examples show the use of amorphous silica (and BF3) to produce alkylates having an RON of no greater than 94.
None of these disclosures shows crystalline transition aluminas which were promoted with Lewis acids at lower temperatures nor any effect upon the NMR
spectrum because of such a treatment. Nor do these 21~3~

~'r disclosures show their~use in isoparaffin/olefin alkylation. These disclosures further do not show any benefit to the alkylation of isoparaffins and olefins using these specifically treated aluminas.

BRIEF DESCRIPTION OF THE DRAWINGS
Figures lA-lD are nuclear magnetic reso~n~e (NMR) plots of certain transition aluminas treated with BF3 at a range of temperatures.
10Figure 2 is a three-~im~ncional graph showing octane sensitivity for the inventive process as a function of olefin feed content.
Figure 3 is an FTIR spectrum showing the effect of the thermal treatment on the free water 15content (1500-1650 cm~~ band) and hydroxyl content (3300-3800 cm~l) of gamma alumina as a function of temperature.
Figures 4A and 4B are graphs showing the effect of specific amounts of free water on the alumina surface on catalyst life (amount of olefin procesc~ or aged) and formula octane number (FON or R+M/2) achieved in the alkylation of a isobutene and mixed butene feed stream.
Figure 5 is a graph showing the effect of initial water and performance in alkylation in terms of ~C8 of alkylate product, RON of alkylate in the mixture, catalyst life (amount of olefin proc~sse~ or age) and the total amount of olefin pro~c~ed prior to significant C8 yield decline.
SUMMARY OF THE I~v~NllON
This invention is variously a catalyst component comprising one or more transitional aluminas which are treated with one or more Lewis acids (preferably BF3) at a fairly low temperature desirably 21~0~g W094/02~3 PCT/US93/06712 so low that the component exhibits æpecific NMR
spectra, an improved catalyst system cont~i n i ~g transition alumina and one or more Lewis acids and a limited amount of water, a catalyst system comprising that catalyst component with free Lewis acid, and an olefin/isoparaffin alkylation process step using these catalyst systems.
Use of the catalyst systems, i.e., the catalyst component in conjunction with free Lewis acid, produces high octane alkylate from isobutane and butene at a variety of reaction temperatures between -30C and 40OC. The catalyst's high activity can result in low operating costs because of its ability to operate at high space velocities as well as enh~nce~ alkylate production.

D~SCRIPTION OF THE INV~NTION
This invention is:
A) a catalyst comronent comprising certain Lewis acid treated transition aluminas, B) a catalyst system comprising the catalyst component in combination with at least a minor amount of free Lewis acid, C) a catalyst component (A) or system (B) cont~; n; ~g limited amounts of water, and D) an alkylation process for producing branched paraffinic products from olefins and isoparaffins using that catalyst system.

The Catalvst Component The catalyst component of this invention comprises or consists essentially of a major amount of t~ansition aluminas (preferably eta- or gamma-alumina) which has been treated with a Lewis acid, preferably BF3. The catalyst component preferably does not W094/02243 2 1 ~ 0 3 ~ ~ PCT/US93/06712 ~

contain any metals (except, of course, aluminum and any metal associated with the Lewis acid such as the semi-metal boron) in catalytic amounts.capable of hydrogenating the hydrocarbons.present in the feeds except those impurity metals which may be present in trace amounts in the Lewis acid or the alumina.

Alumina Aluminum oxide (alumina) occurs abundantly in nature, usually in the form of a hydroxide in the mineral bauxite, along with other oxidic impurities such as TiO2, Fe2O3, and SiO2. The Bayer process is used to produce a reasonably pure Al2O3 having a minor amount of Na2O. The Bayer process may be used to produce a variety of alumina hydroxides:

2~03~

3 PCr/US93/06712 s~
z ~
0 ~ ~ N m N
~J N N o C.

O
--~ O O O O O
~1: . . . . .
O ~ ~ --I N

t'~ ~i N

~D ~
2 0 0 ~ ~ ,~

~ s ) _, s 5 o U ~ C
2 5 .c s~

'D Q) ,r 3 a .c ~ '' o c a ~ o .c The aluminum hydroxides may then be treated by heating to produce various activated or transition aluminas. For instance, the aluminum hydroxide known as boehmite may be heated to form a sequence of transition phase aluminas: gamma, delta, theta, and finally, alpha (see Wefers et al., "Oxides and Hydroxides of Alumina", Technical Paper No. 19, Aluminum Company of America, Pittsburgh, PA, 1972, pp.1-51).
Transition aluminas (and their crystalline forms) include:
gamma tetragonal delta orthorhombic/tetragonal eta cubic theta monoclinic chi cubic/hexagonal kappa hexagonal lambda orthorhombic Activated aluminas and aluminum hydroxides are used in various chemical processes as catalyst and adsorbents.
The aluminas suitable for use in this process include the noted transition aluminas: gamma, delta, eta, theta, chi, kappa, rho, or lambda. Especially preferred are gamma- and eta-aluminas. Nixtures of the two are also desireable.
Since it is difficult to produce a substantially pure single phase transition alumina, mixtures of various aluminas are tolerable so long as a major amount of the specified alumina, e.g., an amount greater than about 50% by weight of the alumina present in the catalyst, is present in the catalyst. For instance, in the production of eta-alumina, gamma-alumina is often concurrently present in the resulting product. Tn~P~, x-ray diffraction analysis can only 21~3~
W094/02~3 PCT/US93/06712 difficultly detect the difference between the two phases. Aluminum hydroxides (boehmite, gibbsite, etc.) may be present in the predominately transition phase product in more than trivial amounts so long as they do not substantially affect the desired alkylation reaction.
While the surface area of the alumina may suitably vary over a wide range dependent on the specific type of transition alumina employed, best results in the alkylation process of the invention are associated with the use of aluminas having surface areas in ~cess of about 160 m2/g. Accordingly, transition aluminas having surface areas above 160 m2/g are preferred with aluminas having surface areas in the range of about 200 to about 400 m2/g being most preferred.
The alumina may be produced in any appropriate form such as pellet, granules, bead, sphere, powder, or other shape to facilitate its use in fixed bed, moving bed, slurry, or fluidized bed reactors.

TPwis Acids The catalyst component of this invention contains one or more Lewis acids in conjunction with the alumina noted above. A Lewis acid is a molecule which can form another molecule or an ion by forming a complex in which it accepts two electrons from a second molecule or ion. Typical strong Lewis acids include boron halides such as BF3, BCl3, BBr3, and BI3; antimony - pentafluoride (SbF5); aluminum halides (AlCl3 and AlBr3); titanium halides such as TiBr4, TiCl~, and TiCl3;
zirconium tetrachloride (ZrCl4); phosphorus pentafluoride (PF5); iron halides such as FeCl3 and 21~3G~

W094/n2243 -14- PCT/U593/06712 FeBr3; and the like. Weaker Lewis acids such as tin, indium, bismuth, zinc, or mercury halides are also acceptable. Preferred Lewis~acids are boron contA; n; ng materials (BF3, Bc13, Bbr3,-~and BI3), SbF5, and AlCl3;
most preferred is BF3.
It is believed that the Lewis acid forms complexes or surface compounds with the alumina substrate. In particular, we believe that BF3 strongly adsorbs in the vicinity of the hydroxyl groups found on the alumina surface and additionally is physi-sorbed at the alumina surface.
The total amount of Lewis acid in the alumina surface is between 0.5% and 40% by weight of the catalyst dep~n~;~g in large measure on two factors: the Lewis acid chosen and the susceptibility of the alumina surface to accepting the Lewis acid by chemisorption or by physisorption. In the case of BF3, we believe that 5-20% of the weight of the alumina catalyst component is attributable to BF3 products (e.g., the production of aluminum fluoroborate or similar compounds) and the remainder is physi-sorbed BF3. Preferably, the total amount of BF3 (as BF3 products) added is in ~YC~5 of 7%
by weight of the alumina catalyst component and, most preferably, from about 10% to about 20% by weight of the alumina catalyst component.
To maintain the presence of sufficient Lewis acid on the catalyst composition, we have found it desirable to maintain at least a minor amount of the Lewis acid in the proximity of the alumina surface, preferably in the reaction fluid. This amount is an amount at least sufficient to maintain the concentration of the Lewis acid specified above on the alumina. At the WHSV ranges specified below with regard to the alkylation reaction, we have found that 21g~363 ~ W094/02243 -15-generally an amount of at least 0.5% of Lewis acid (by weight based on the hydrocarbon) is suf f icient to maintain the Lewis acid level on the alumina. For BF3 it is preferred to use BF3 concentrations of about 0.8%
to about 15% (by weight based on hydrocarbon) with BF3 amounts in the range of about l.5% to about 6.0% by weight being most preferred. On an alumina basis, the ratio of free Lewis acid (that is, Lewis acid in the proximity of the alumina but not associated with the alumina by chemisorption or physisorption) to alumina is in the range of 0.05 to 30 g Lewis acid/g Al2O3. For BF3, the preferred range is 0.08 to l0 g BF3/g Al2O3, and more preferably in the range of 0.l0 to 8 g BF3/g Al2O3.

CatalYst Component Prepa~ation The catalyst component may be prepared in a variety of ways including preparation in situ in, e.g., an alkylation reactor by passing the Lewis acid in gaseous form through the vessel cont~;ni~g the transition alumina. Alternatively, the alumina may be contacted with the Lewis acid and later ilLLLoduced into the reactor.
In any case, the alumina may be substantially dry or anhydrous prior to contact with the Lewis acid and maintained in a state of dryness, i.e., maintAine~
at a very low free H2O content. The alumina phase chosen in conjunction with proper treatment of the alumina to maintain the presence of hydroxyl ~LVU~
(usually by maintaining the alumina at temperatures below 450C during pretreatment) allows the presence of about 4-l0 hydroxyl groups per l00 A2 of alumina surface area. Preferred is 6-l0 hydroxyl groups per 100 A2 of alumina surface area. The alumina is - preferably completely hydroxylated since that 21~0~
W094/02~3 PCT/US93/06712 hydroxylation, in turn, permits the formation of the maximum amount of the Al-OH-Lewis acid complex, believed to be one element of the active alkylation catalyst at the alumina sur~ace. The alumina may be partially or substantially dehydroxylated but the catalyst is not as efficacious.
Alumina, as received from the manufacturer or exposed to the atmosphere for appreciable periods of time, picks or adsorbs substantial water. Careful heating and control of the atmosphere surrounding the alumina is consequently desirable. Suitably, the alumina is heated at a temperature below 500C and preferably at a temperature in the range of about 50C
to about 400C prior to treatment with the Lewis acid.
Additionally, free water (in distinction to the water which may be identified as hydroxyl groups on the alumina surface) may be present in limited amounts in the alumina. The free water content in the alumina is suitably less than about 15% by weight but preferably is less than about 8.0% by weight. Most preferably the free water content of the alumina is between 0.5 and 6.0% by weight. Higher amounts of water appear both to degrade the catalyst and to impair the effectiveness of the catalyst in the practice of the alkylation reaction. Higher amounts of water also tend to form compounds, such as BF3 hydrates, which are corrosive and therefore undesirable.
The use of Lewis acid promoted transition aluminas having the limited free water content as set forth above in a process of alkylating lower olefin with isobutane has several surprising benefits. This catalyst component or catalyst composition improves the octane number of the resulting alkylate, t~e p~rcent2ge of C8 in alkylate, and the effective life of the catalyst before regeneration. We have not observed ~ 21~0~
W094/02~3 PCT/US93/06712 these advantages when water is added to the alkylation process feedstock.
Lewis acid-alumina, contact temperatures between -25C and less than abou~ 150C are acceptable;
a temperature between -25C and 100C is desirable; a temperature between -30C and 30C is preferred. The partial pressure of gaseous Lewis acid added to the alumina is not particularly important so long as a sufficient amount of Lewis acid is added to the alumina. We have found that treatment of the alumina with BF3 at the noted temperatures will result in an alumina-BF3 complex contA;n;ng BF3 sufficient to carry out the alkylation. The alumina contains between 0.5 and 30% by weight of BF3. We have observed that æolid state boron-nuclear magnetic re~QnAnce (lIB-NMR) analysis of the catal~st component provides evidence (a pronounced peak at about -21.27 ppm relative to boric acid) of tetragonal boron in the catalyst composite produced at the lower temperatures. Aluminas treated with BF3 at temperatures of 150C and higher show spectra which are indicative of the presence of trigonal symmetry about the boron. We prefer catalysts in which the relative amounts of trigonal boron:tetragonal boron (as calculated by the integration of the respective llB-NMR spectra) are in the range of 0:1 to 1:1. More preferred is the range of 0:1 to 0.25:1; most preferred is 0:1 to 0.1:1.
Obviously, the alumina may be inco~o~ated into a binder prior to its treatment with Lewis acid.
The binders may be clays (such as montmorillonite and kaolin) or silica hAc~A materials (such as gels or other gelatinous precipi~ates). Other binder materials include carbon and metal oxides such as alumina, silica, titania, zirconia, and mixtures of those metal oxides. The composition of the binders is not :

21~03~ ~

particularly critical but care must be taken that they not substantially interfere with the operation of the alkylation reaction.
The preferred method for incorporating the catalytic alumina into the bind y is by mixing an aluminum hydroxide precursor (sùch as boehmite) with the binder precursor, forming the desired shape, and calcining at a tPmrPrature which both converts the aluminum hydroxide precursor into the appropriate transition phase and causes the binder precursor to bind the alumina particles. The absolute upper temperature limit for this calcination is about 1150C.
Temperatures below abou~ 1000C may be ap~o~Liate.

Alkylation Process The inventive catalyst component and the allied catalyst composition are especially suitable for use in alkylation processes involving the contact of an isoparaffin with an olefin. The catalyst component should be used in conjunction with an amount of free Lewis acid.
Specifically, the catalyst system (the inventive catalyst component in combination with a free Lewis acid) is active in alkylation reactions at low temperatures (as low as -30C) as well as at higher temperatures (nearing 50C). Lower temperatures (-5C
to 15C) are preferred because of the ~nhAnC~ octane of the alkylate produced and are particularly preferred if the feedstream contains more than about 1%
isobutylene. Higher temperatures also tend to produce larger amounts of polymeric materials.
The pressure used in this process may be between atmospheric pressure and about 750 psig.
Higher pressures within the range allow ~ecovery of excess reactants by flashing after the product stream 2140~63 W094/02~3 PCT/US93/06712 leaves the alkylation reactor. The amount of catalyst used in this process depPn~c upon a wide variety of disparate variables. Nevertheless, the Weight Hourly Space Velocity ("WHSV" - weight of olefin feed/hour .
weight of catalyst) may effectively be between 0.1 and 120, especially between 0.5 and 30. The overall molar ratio of isoparaffin to olefin may be between about 1:1 to 50:1. With recycle reactors the paraffin to olefin ratio could be substantially higher and could PYcee~
1000:1. The preferred range is between 2:1 to 25:1;
the more preferred range is between 3:1 to 15:1.
The feedstreams intro~llcP~ to the catalyst are desirably chiefly isoparaffins having from four to ten carbon atoms and, most preferably, four to six carbon atoms. Isobutane is most preferred because of its ability to make high octane alkylate. The olefins desirably contain from three to twelve and preferably from three to five carbon atoms, i.e., propylene, cis-and trans-butene-2, butene-1, and amylene(s).
Preferably, the olefin stream contains little (if any) isobutylene. Similarly, for the inventive catalysts the process works better in producing high octane alkylate if the feedstream contains little or no butadiene (preferably less than 0.2% to 0.3% molar of the total olefins) and a minimal amount of isobutylene, e.g., less than about 2.5% molar based on the olefins.
Although the catalyst alkylates butene-1, it is preferred to operate with a minimum of butene-l, e.g., less than about 10% by mol, since it lowers the octane values of the resulting alkylate. Of course, if it is desired to operate a process with high throughput rather than with highest octane, a higher level of butene-l is tolerable. An excellent source of a feedstock containing a low level of isobutylene is the 2~3~3 ~

W094/02~3 PCT/US93/06712 raffinate from a process which produces methyl-t-butylether (MTBE).
The water content of the feedstocks may vary within wide limits, but preferably is at a low level.
The water content should be less than about 200 ppm (by weight) and most prefera~ly less than about 50 ppm (by weight). Higher levels of water content tend to lower the octane value of the resulting alkylate and form corrosive hydrates or reaction products with the Lewis acids. Because the sources of most alkylation unit feedstocks tend to introduce water into those feeds, we prefer to dry one or more of the feedstocks to achieve the preferred water content.
The feedstocks should contain a minimum of oxygenates such as ethers and alcohols. Oxygenates appear to lessen substantially the effectiveness of the catalyst system.
The process of this invention includes increasing the effective catalyst life by con~llcting the alkylation process with isobutane and lower olefins using catalyst components and catalyst compositions having the limited free water content specified above in the discussion of preparation of the transition alumina catalyst compound and catalyst composition.
The products of all variations of this alkylation process typically contain a complex mixture of highly brAnch~A alkanes. For instance, when using isobutane as the alkane and n-butylene as the olefin, a mixture of 2,2,3-; 2,2,4-; 2,3,3-; and 2,3,4-trimethylpentane (TMP) will result often with minor amounts of other isomeric or polymeric products. ~he 2,3,4-TMP isomer is the lowest octane isomer of the noted set. The 2,2,3- and 2,2,4-TMP isomers are higher octane components. Calculated average octane values (the average of the Research Octane Number (RON) and 21~03~
W094/02~3 PCT/US93/06712 the Motor Octane Number (MON), as denoted by (R + M)/2)of the various C8 isomers are:
-Isomer Octane (R + M)/2 2,2,3- 104.8 2,2,4- 100.0 2,3,3- 102.8 2,3,4- 99.3 The process may be carried out in the liquid, vapor, or mixed liquid and vapor phase. Liquid phase operation is preferred.

The invention has been disclosed by direct description. Below may be found a number of examples showing various aspects of the invention. The examples are only examples of the invention and are not to be used to limit the scope of the invention in any way.

EXAMPLES
Example 1 CatalYst Testinq This example shows the preparation of a number of alumina-based catalysts in situ and their subsequent use in an alkylation reaction using model feeds. It is used to evaluate catalyst activity and selectivity.
The alumina samples were dried at 110C
overnight and charged to a semi-batch reactor having an internal volume of about 500 cc. The reactor temperature was controllable over the range of -50C to 40C. For initial catalyst treatment, the reactor contA; n; ng the catalyst was purged with an inert gas and cooled to about 0C. About 275 cc of isobutane was 21403~9 ' : ~
W094/02~3 PCT/US93/06712 added to the reactor. After a brief degassing, BF3 was added batchwise. After BF3 is added, the temperature of the reactor rises and the pressure typically drops as the alumina adsorbs or reacts with the BF3.
Additional infusions of BF3 are made until the pressure in the reactor no longer drops. The BF3 saturation equilibrium pressure was about 40 psig. The liquid phase concentration of BF3 was about 1.5%. At that point the alumina had adsorbed or reacted with all of the BF3 possible at that temperature and the catalyst was in its most active form.
A 4/1 molar mixture of isobutane and trans-2-butene was added to the reactor at a WHSV of 3.5 until the paraffin to olefin ratio reached 25.
The product alkylate was then removed from the reactor vessel and analyzed using gas-liquid chromatography.
The results of those runs are shown in Table 1.
Table 1 ~C~ in Alumina TYpeSurface Area Alkylate Product gamma 180 m2/gm 95.4 gamma 116 m2/gm 82.07 delta 118 m2/gm 94.3 pseudoboehmite352 m2/gm 74.2 bayerite 40 m2/gm 69.1 pseudoboehmite250 m2/gm 59.6 boehmite 150 m2/gm 59.8 It is clear from these pr~l iri~ry scre~ning data that the transition ~gamma and delta) aluminas produce significantly higher percentages of C8 in the product alkylate than do the other aluminum hydroxide 2~.~036g~

catalysts. The result did not appear to correlate to the specific surface area of the catalyst.

~Ample 2 Catalyst Screening This example compares the performance of eta-alumina (a preferred form of the inventive catalyst) with representative samples of other acidic oxides each combined with BF3 for the reaction of isobutane with butylenes to produce alkylate.
The eta-alumina sample was prepared by a controlled thermal treatment of bayerite (Versal B from LaRoche Chemical) for 15 hours at 250C and 24 hours at 500OC under a N2 atmosphere.
The comparative oxidic materials were:
silica-alumina, synthetic mordenite zeolite, and fumed silica. The silica-alumina (obtained from Davison Chemical) contAine~ 86.5~ sio2 and had a surface area of 392 m2/gm. It was used without further treatment.
The mordenite was a hydrogen form zeolite and was obtained from Toyo Soda. It was prepared from Na-mordenite and subjected to ion exchange, steam treatment, and calcination to achieve a Si/Al ratio of 28:1.
Each of the samples was dried at 110C
overnight and introduced into the semi-batch reactor described in Example 1. The samples were purged with a dry inert gas and cooled to 0C. Isobutane was added to the reactor to an initial volume of 100 cc. BF3 was added with stirring until an equilibrium pressure of 30 psig was obtained.
A mixture of isobutane/t-2-butene was fed to the reactor. At the completion of the reaction, alkylate was removed and analyzed by gas-liquid chromatography. The RON were calculated from the gas--214~3.~

liquid chromatography data using the well-known correlations in Hutson and Logan, "Estimate Alky Yield and Quality", Hydrocarbon Processing, September, 1975, pp. 107-108. The summary of the experiments and results is shown in the following Table 2:

~ 21~36b WO 94/02243 PCI'/US93/06712 Oa~ D~ O _I
. . -O ~ O~ O ~ O
_I

a~
5 0 r a~ ~ o ~ ~ o , a~ o o d ~ ~ O O In ~ co ~ o ,i ~i ~ o d Cl 1` C~ O ~ t~l CO O N 1 I ~ ~ o o ~ ~ ~ o o ~ u~ a~ ~i _i ~ ~ ~ o r Q
~ n ~1 l` ~ o o ~ a~
E~ .. . . . . . . .. . .
2 n C~ ~ ~ o t~ o ~ 1~ ~1 V _ 0~ ~ ~ o ~ ~ a~ a~
d IY

2 5 -- ~, tJ` C ~: -- C 3 ,, ~ æ a~
~ U~ ~ r ,~
~ G

c L., ~ _ L 1 ~J r = c u u ~ c c- ~ o ~ a z ~ .
U E~ O

21~36g.".~

Clearly, for the eta-alumina catalyst, the yield of C8's was significantly higher; the overall yield and RON were much better.

~m~le 3 This example shows that the addition of either water or methanol produces no appreciable improvement on the alkylation of butene-2 with isobutane using the inventive alumina catalyst.
Indeed, water and methanol appear to be detrimental.
Three separate semi-batch reactors were dried and flushed with nitrogen. A sample of 2.5 gm of a gamma-alumina (LaRoche VGL) was loaded into each bottle. The alumina samples had been previously dried at 110C overnight. An amount of 0.278 gms of deionized water was added dropwise to one reactor. An amount of 0.988 gms of methanol was added to another reactor. These amounts were calculated to be 10% of the catalyst plus water equivalent. The rem~; n; n~
reactor was used as a control reactor. Isobutane (246 cc) was added to each bottle; BF3 was added (with stirring) until the pressure reached a constant 30 psig. A feedstock of isobutane and 2-butene was continuously added in a ratio of 2:1 and at a rate of 1.6 cc/minute. The reaction continued for about 75 minutes after which samples of the reactor liquids were removed and analyzed using a gas-liquid chromatograph.
The conversion of olefin was more than 99% in each case. Other reaction conditions and a summary of reaction results are shown in Table 3:

21~0369 `` i WO 94/02243 PCI'/us93/06712 O o o ~

~, ..
.¢

~ d~
~ ~ o ~
OU~ I O
;~ . . . . . .. .
oou~ o ~a~ ~o~ ~OD
,.

Q d ~., ~ ~ d~ ~
~- ~ O ~ ~ t~ O ~'7 E- ~ I~ ~ o 01 'I ~ ~1 a~ a~ o a~

-C~
o -Q~
U
C
~ ~5 .
.,1 ) ~
~, ,1 _ U~ ~Q

0 3 ~ 3 C O
~ ~ ~n, 3 ~ ~ ~ v ~ ~
0 ~ ~ _ S'~ IV~ OD ~ ~ O ~

4 ~ 4 V C.) C.) ~ ~ p; _ 2 1 ~ 036 9 i ; i i ~ ~ ~

It is clear that neither water nor methanol created any advantage in the operation of the process in producing a gasoline alkylate. The gross amounts of C8 pro~llc~ were smaller than for the inventive alumina; the amount of undesirable C,2+ were two to four times higher than for the inventive alumina. The yields were lower and, probably most importantly, the octane values of the comparative products were significantly lower.
T~Y~mple 4 This example shows the suitability of the inventive catalyst (gamma-alumina, T~T~och~ GL) for a variety of olefin feedstocks. The following reaction conditions were used for the test series:

Temperature 0C
Total pressure 30 psig 2 A semi-batch reactor was utilized in each run.
The olefin feedstocks were mixtures which were chosen to allow us to identify desirable and undesirable combinations of feed materials. The mixtures are shown in Table 4:

21~0389 o 1,1~
U

X ~ o ~ ~ o ~ o o ~ a ~ ~
~r 0 U

ll o o o ~ u~
c~ N N N N O O O O

c,~ Irt O O Ul In o o E~l I N N ~1 _I N N _I ~i ~

U In o ~ o ~ o ~ o N _I N ~I N _~ N ~

z ~i N ~ ~ In ~O t` CD

3 0 ~:

21~L03~9 The products made were analyzed using gas-liquid chromatography and their respective octane numbers are shown in Table 5:

. .

~ 214036~
WO 94/02243 PCI'/US93/06712 ~ o OD a~ o ,i Z ' ~ ~ a~
~o ~o oo o a~ a~ N

+ ~ a~ ~ o ~ ~ ~
_ , ~ o t~ t~ ~ ~

S
2 0 o a' 2 5 C) ,, U~ ts) ~ o ,~
.
.
z X
'~:

21~0~
W094/02~3 PCT/US93/06712 -This data shows that increa es in isobutene and propylene feed concentrations directionally cause the inventive alkylation process to produce lower alkylate C8 content. As shown in Figu~é,2, smaller amounts of either C3- or i- C4~ cause no more harm to alkylate quality but are generally undesirable if extremely high octane alkylates are nececc~ry.

~x~m~le 5 This example demonstrates the performance of the transition alumina/BF3 catalysts in reacting isobutane with butenes to form high octane product under conditions of high space velocity and low paraffin/olefin feed ratios.
A sample of gamma-alumina (VGL, LaRoche) was dried overnight at 110C and loaded into the semi-continuous reactor unit described in Example 1. The catalyst was purged with dry inert gas and cooled to ooc. Isobutane was added to the reactor and then the system was exposed to BF3 under stirring conditions until an equilibrium pressure of 30 psig was achieved.
A feed comprising pure trans-2-butene was then pumped into the reactor under vigorous stirring conditions over a period of 60 minutes; samples were obt~i n~
periodically during the run (at 30 and 60 minutes).
The results are summarized in Table 6 below:

2 1 ~

W094/02~3 PCT/US93/06712 Table 6 Catalyst charge (g) 2.5 Temperature (C) 0 i-C4 initial charge (ml) 300 Olefin feed Trans-2-butene Space velocity (WHSV) 26.4 Run time (minutes) 30 60 Equivalent external i-C4/C4 5.4 2.6 Butene conversion (%) 100 100 Product analysis (weight %):
C5-C7 3.2 4.7 C8 saturates 91.1 81.9 0 C9+ 5.7 13.4 TMP/C8 total (%) 97.6 96.6 RON 99.0 96.8 Octane, R+M/2 97.0 95.3 ~m~le 6 This example shows the utility of the catalyst system on a feed obt~ine~ from a refinery MTBE
unit. The feed, containing minor amounts of butadiene and isobutene, was introduced into a bed of a commercial hydroisomerization catalyst (0.3% Pd on Al2O3) at 400 cc/hr, 80C, and 350 psig along with 14 sccm H2. The molar ratio of H2:butadiene was 6:1. The thusly treated feed, cont~ g no butadiene and 0.52 %
(molar) of isobutene, was mixed with an appropriate amount of isobutane. The mixture had an approximate composition as shown in Table 7 below:

21~0~9 W094/02~3 PCT/US93/06712 Table 7 ComPonent ~; mole %
propylene ,;~ 0.02 propane 0.13 isobutane 80.14 isobutene 0.52 1-butene 0.75 butadiene ---n-butane 3.84 t-butene-2 8.23 c-butene-2 4.05 3-methyl-1-butene 0.01 isopentane 1.73 1-pentene 0.01 2-methyl-1-butene 0.03 n-pentane 0.08 t-2-pentene 0.18 c-2-pentene 0.06 2-methyl-2-butene 0.23 This mixture had an isoparaffin to olefin ratio of 5.8:1 and an isobutane/olefin ratio of 5.7:1.
The mixture was then admitted to a pair of continuous laboratory reactors each con~in;ng 280 cc of liquid and con~in;ng 5.04 g of catalyst. The temperature was maint~;ne~ at 0F. The WHSV for the reactor was 4.3 hr-l and the LHSV was 1.07 hr~~. The catalyst was a gamma alumina (~o~he VGL) and was prepared by adding the proper amount to the reactors along with a small amount of isobutane, pressuring the reactor to about 40 psig of BF3, and maint~;n;ng that pressure for the duration of the test. The test was run for 41 hours total time. The catalyst was regenerated four times during the run by rinsing the catalyst in 200cc of trimethyl pentane, heating to 150C in air for 45 minutes to volatilize a portion of the reaction product on the catalyst, and heating the catalyst to 600C in air for 60 minutes to oxidize the remaining hydrocarbonaceous materials. Small amounts of the catalyst were added as necesC~ry with the 21~0359 regenerated catalyst to restore the catalyst to its proper amount upon return to the reactor (0.41 g @
cycle 2, 0.97 g @ cycle 3, 0.0 g @ cycle 4, and 0.47 g ~ cycle 5). About 4.5 liters (3.2 kg) of stripped Cs+
alkylate was collected having about 7.6% C~7, 81.2% C8, 4.4% C~ll, and 6.8% Cl2 (all by weight). Using the Hutson method disc~ P~ above, the octanes were calculated to be: RON = 96.6, MON = 93.3, and the (R+M)/2 = 94.95. The product was then engine-tested using API methodology and the octanes were measured to be: RON = 98.7, MON = 93.85. The resulting (R+M)/2 =
96.28. The Hutson method clearly underestimated the RON octane values for this process.

T~YAmple 7 This example shows the preparation of a number of BF3/alumina-based catalyst components. One is made in accord with this invention and three are comparative samples. Each of the samples was then tested in an alkylation reaction using model feeds and isobutane and butenes.
All four gamma-alumina samples (TARo~hP-Versal GL) were infused with BF3 in a Cahn hAl~nce.
Use of a Cahn hAl~nc~ allowed close control of the temperature at which the alumina contacted the BF3 and further allowed the weight gain to be measured during the treatment. The four samples were treated with BF3 respectively at 25C, 150C, 250C, and 350C. A
sample of each of the catalyst components was removed and analyzed using llB- MAS-NMR. The results of these analyses are shown in the figures: Figure lA shows the treated alumina at 25C; Figures lB, lC, and lD show the respective da~a from the 150C, 250C, and 350C
treated alllm; n~ . In Figure lA, there is a pronounced 21~3~

sharp peak at about -21.27 ppm (relative to boric acid) suggesting significant tetragonal boron content. The other three NMR plots do not show such a sharp peak.
Instead, the data suggest the presence of substantial trigonal boron.
The four gamma-alumi,n,a~samples (LaRoche-Versal GL) were then charged to a semi-batch reactor having an internal volume of about 500 cc. The reactor temperature was controllable over the range of -5C to 40C. For initial catalyst treatment, the reactor cont~ining the catalyst was purged with an inert gas and cooled to about 0C. About 275 cc of isobutane were added to the reactor. After a brief degassing, BF3 was added batchwise. Additional infusions of BF3 are made until the pressure in the reactor no longer drops. The BF3 saturation equilibrium pressure was about 40 psig. The liquid phase concentration of BF3 was about 1.5%.
A mixture of isobutane/trans-2-butene was fed to the reactor. At the completion of the reaction, alkylate was removed and analyzed by gas-liquid chromatography. The RON's were calculated from the gas-liquid chromatography data using the well-known correlations in Hutson and Logan, "Estimate Alky Yield and Quality", Hydrocarbon Processing, September, 1975, pp. 107-108. The summary of the experiments and results is shown in Tables 8 and 9 below:

2~03~9 WO 94/02243 PCr/US93/06712 c; _I ~ o O ~ a~ ~D
O ~ 0 ~ 1~
o _1 ~1 ~ _I
O ~ a~
1 0 ~ ~ ,i o o ~ 0 ~ u~
~o o_I

,~ ~ In o O ~ a~
~ O O ~ 0~O In .~ ,~ ~ ~ o ~1 u a~
oo ~ ,~ qo ~o ~ r 0 _I ~ ~ o o u~
.4 ~ ~ ~ ~D O_I
E~ ) o ~ u 2 5 z D~ J ~ ;~ _ c a c~ t) ~ ~ U ~cn H H ~1 3 w w ~

Table 9 Product Summary c~
Rample No. 1 2 3 ~ c~
Total alkylate 27.63% 19.97% 11.48% 5.62%
Butene conversion 100.0% 86.15% 69.09% 67.03%
Cs7 hydrocarbon 1.51% 2.53% 2.55% 0.83%
C8 hydrocarbon 93.33% 87.58% 85.14% 70.56%
C9 ll hydrocarbon 0.49% 3.12% 6.45% 13.90%
Cl2+ hydrocarbon 4.67% 6.77% 5.86~ 14.72%
TMP/C8 97.54% 98.27% 96.70% 97.55% w Yield (w/w) 1.94 1.40 0.80 0.39 -RON 99.26 98.09 97.57 92.23 MON 94.88 93.73 93.16 90.07 (R + M)/2 97.07 95.91 95.36 91.15 2,2,4/2,3,4 0.81 0.54 0.48 0.33 21~0~

W094/02~3 PCT/US93/06712 It is ~lear from the data that the catalyst component treated with BF3 at the lower temperature is superior in operation in most practical aspects (conversion, C8 production, alkylate yield, RON, MON, etc.) than the other materials.

F~mple 8 This example compares the results of a variety of catalyst components and compositions (comprising a transition alumina and BF3 and a variety of water contents) when used in an alkylation process.
The intent was to compare the water content--whether the water was in the form of surface hydroxyl content or in the form of "free" or surface-adsorbed water--in the catalyst to the octane number and C~ content of the resulting alkylate.
A large batch of commercial alumina (LaRoche-V-GL-Versal-250- a gamma alumina apparently made by calcination of pseudo-boehmite) was transferred from the as-received can into glass evaporating dishes. The glass evaporating dishes are maintained in a drying oven at 110C.
This alumina is believed to be fully hydroxylated as it is received from LaRoche. By "fully hydroxylated" is meant that substantially each surface octahedral aluminum is terminated by an "-OH" group.
In addition, there likely is some surface bound H2O (or "free water" as was ~iccl~ssed above) dep~n~;ng upon the temperature, relative humidity, and h~n~l ing history of the material.
We determined the temperature at which the surface water was removed (without substantial dehydroxylationj by placing an alumina sample taken from the drying oven in a Fourier Transform Infra-Red (FTIR) analyzer and made a series of scans at 214036~
W094/02~3 PCT/US93/06712 ,~.
progressively higher temperatures (25C, 80C, 125C, 175C, and 225C) under a dry helium purge stream.
By following the progression of the H-O-H
h~n~i~g band of line A in Figure 3 at 1640 cm~', it may be observed that dehydration is essentially complete between 175C and 225C. Although some small amount of dehydroxylation likely would occur as a result of the rise to this temperature, to a good approximation, the loss in weight occurring up to 200C is equal to the amount of surface bound or "free" water on the surface of the alumina sample.
Samples of the alumina were then subjected to treatment with water vapor so to load specific amounts of water onto the alumina surface. This was done by placing the alumina samples in a closed vessel with distilled water held at a specific temperature. The liquid water was not placed in contact with the alumina but instead was susp~n~e~ in the vessel creating an atmosphere cont~ining water in equilibrium at the chosen temperature. The samples were held in the vessel for two hours each to allow equilibration between the alumina and the water vapor. The temperatures of treatment were variously at 0C, 18C, and 30C. These three samples and a sample taken directly from the drying oven were each placed in a microbalance boat and the weight loss to 200C
determined.
In addition, each of the samples was heated in the microbalance to 1075C, a temperature at which substantially complete hydroxylation is achieved. At temperatures above about 200C, the samples continue to lose weight. This is thought to be due to the condensation of Al-OH to form HzC, Al+, alld O~.
The results of these runs are shown in Table 10 below:

21~g3~

WO 94/02243 -4 1- PCI~/US93/06712 N ~ ~ i O O O ~
~ X

O
0 ~D O ~1 ~O
oooooo o O ~
--I ~It~U~ I OOOOOO
~J o ,r P~
E~

o~ ov V
O OD O

O O O ~
U U V C~ ov O ., c~ O ., c ,~ In o~ o~ o~ ~~

.

W094/02243 2 ~ 3 ~ g -42- PCT/US93/06712 -Several catalyst samples, after treatment with the temperature and water vapor treatments specified above, were then subjected to an alkylation reaction to check the cv~ L eOpondence between the products proA~lc~ and the respective water contents.
Care was taken to prevent evaporative water from being introduced into the catalyst. The seven catalysts contained: 18% ~0, 6% H2O, 3% H2O (i.e., after removal from drying oven), fully dehydrated at 2.1 meq Al-OH/gm (after 200C pretreatment).
The alkylation reaction utilized a model feed of isobutane and mixed butenes (I/O=6:1; where the butenes were trans-2-butene=94%, 1-butene=5~, and isobutene=1%). The feed had been twice dried using freshly regenerated 3A zeolite beds to lower the water content of the feed to less than 10 ppm. Commercial C~'s purchased from vendors typically contain 20-40 ppm of H2O. The BF3 co~s~ntration was held at about 1.8 wt.% of the total liquid weight. The reaction pressure was 45 psig; residence time was 56 minutes; the catalyst concentration was 1.5%; and the reaction temperature was 0C.
The results of these runs are shown in Figures 4A and 4B. The catalyst having full hydroxylation and 3% free (or surface) water clearly is superior both in %C8 produced and in the octane of the resulting alkylate.

~mple 9 This example shows the interrelated effects of water BF3/transition alumina catalysts on the age of that catalyst and C8's in alkylate product.
In thi example, four cataiysts h~ on the transition alumina utilized in Example 8 (gamma-phase alumina - LaRoche VGL) were treated also as ~;~C11RSe~

21~0~
W094/02~3 PCT/US93/0671 in Example 8 to produce aluminas having 1 to 1.5% H2O, 3~ H2O, and 7% H2O (two batches).
The reactor was a Hastelloy autoclave operated in CSTR mode, with continuous addition of feed and BF3 and with continuous withdrawal of product alkylate along with isobutane and BF3. The feed was treated both with 3A and 13X mol~c~ r sieves to remove water and other impurities.
Each of the catalysts was used in an alkylation process operated in the following procedure:
The alumina was loaded into a tube and pretreated with humidified nitrogen at a temperature necessary to achieve a desired water content in the alumina. At the start-up of the CSTR reactor, an equilibrium mixture of isobutane and alkylate was cooled to 0C and pressurized with BF3 to 50 pounds pressure (gauge). The pretreated alumina was introduced into the reactor through a port using liquid isobutane to carry the alumina. The reaction was initiated by introducing the 6:1 isobutene/olefin feed derived from a hydroisomerized MTBE raffinate. The olefin composition was:

butene-2 92.0%
butene-1 4.8%
isobutene 3.2%

The reaction conditions were: 0C, 3%
catalyst slurry co~cDntration and a WHSV of 8.7 to 9.
Samples were taken at several times throughout the course of the reaction. The reaction was run until a clear pattern of deactivation was cbserved.
As is shown in Figure 5, the catalyst cont~;ning 3% H2O maintained its ability to produce C8's ~14~36~

for a much longer period of time or catalyst age. In a qualitative side, the optimization of moisture content of the catalyst produced an alkylate having a specific C8 content for about 50% longer~than catalysts cont~in;ng either l.5% or 7S H2O.
It should be clear that one having ordinary skill in this art would envision equivalents to the processes found in the claims that follow and that these equivalents would be within the scope and spirit of the claimed invention.

Claims (56)

WE CLAIM AS OUR INVENTION:

1. A catalyst component comprising a transition alumina which has been contacted with a Lewis acid at a treatment temperature below about 150°C
to produce a catalyst component containing Lewis acid.

2. The catalyst component of claim 1 where the transition alumina is selected from gamma-alumina, eta-alumina, theta-alumina, chi-alumina, kappa-alumina, rho-alumina, and lambda-alumina mixtures.

3. The catalyst component of claim 2 where the transition alumina is selected from gamma-alumina, eta-alumina, and mixtures.

4. The catalyst component of claim 1 where the treatment temperature is below about 100°C.

5. The catalyst component of claim 4 where the treatment temperature is below about 30°C.

6. The catalyst component of claim 1 additionally comprising less than about 15% in weight free water.

7. The catalyst component of claim 6 where the free water content is less than about 8%.

8. The catalyst component of claim 7 where the alumina has a surface area in excess of 160 m2/g.

9. The catalyst component of claim 1 where the Lewis acid is BF3.

10. The catalyst component of claim 9 additionally comprising less than about 15% by weight free water.

11. The catalyst component of claim 10 where the free water content is less than about 8.0%.

12. The catalyst component of claim 11 where the free water content is 0.5 to 6.0%.

13. A catalyst component comprising a transition alumina which has been contacted with a boron containing-Lewis acid at a treatment temperature below about 150°C to produce a catalyst component containing the boron-containing Lewis acid.

14. The catalyst component of claim 13 where the transition alumina is selected from gamma-alumina, eta-alumina, theta-alumina, chi-alumina, kappa-alumina, rho-alumina, and lambda-alumina mixtures.

15. The catalyst component of claim 14 where the transition alumina is selected from gamma-alumina, eta-alumina, and mixtures.

16. The catalyst component of claim 13 where the treatment temperature is below about 100°C.

17. The catalyst component of claim 16 where the treatment temperature is below about 30°C.

18. The catalyst component of claim 13 where the boron-containing Lewis acid is BF3.

19. The catalyst component of claim 13 additionally comprising less than about 15% by weight free water.

20. The catalyst component of claim 19 where the free water content is less than about 8.0%.

21. The catalyst component of claim 20 where the free water content is 0.5 to 6.0%.

22. The catalyst component of any of claims 13-21 in which the 11B-MAS-NMR exhibits a trigonal boron: tetragonal boron ratio between 0.0:1 and 1:1.

23. A catalyst component comprising a transition alumina selected from gamma-alumina, eta-alumina, theta-alumina, chi-alumina, kappa-alumina, rho-alumina, lambda-alumina and mixtures which has been contacted with a boron containing-Lewis acid to produce a catalyst component containing between 0.5% and 30% by weight of the boron-containing Lewis acid and which the 11B-MAS-NMR of the catalyst component exhibits evidence of tetragonal boron.

24. The catalyst component of claim 23 where the boron-containing Lewis acid is BF3.

25. The catalyst component of claim 24 additionally comprising less than about 15% by weight free water.

26. The catalyst component of claim 25 where the free water content is less than about 8.0%.

27. The catalyst component of claim 26 where the free water content is 0.5 to 6.0%.

28. The catalyst component of any of claims 23-27 in which the 11B-MAS-NMR exhibits a trigonal boron: tetragonal boron ratio between 0.0:1 and 1:1.

29. An alkylation catalyst system comprising a. an alumina alkylation catalyst component of a transition alumina which has been contacted under substantially anhydrous conditions with a Lewis acid to produce an alkylation catalyst containing Lewis acid, and b. an amount of that free Lewis acid sufficient to maintain the Lewis acid concentration of the alumina alkylation catalyst component.

30. The catalyst system of claim 29 where the transition alumina is selected from gamma-alumina, eta-kappa-alumina, theta-alumina, chi-alumina, kappa-alumina, rho-alumina, lambda-alumina and mixtures.

31. The catalyst system of claim 30 where the transition alumina is selected from gamma-alumina, eta-alumina, and mixtures.

32. The catalyst system of claim 29 where the Lewis acid is BF3.

33. The catalyst system of claim 32 in which the alumina catalyst component contains less than about 15% by weight of free water.

34. The catalyst system of claim 33 in which the alumina catalyst component contains less than about 8% by weight of free water.

35. The catalyst system of claim 34 in which the alumina catalyst component contains 0.5 to 6.0% by weight of free water.

36. The catalyst system of claim 30 where the Lewis acid is BF3.

37. The catalyst system of claim 32 additionally comprising isobutane and butylene.

38. An alkylation process comprising the steps of:
a. contacting a mixture comprising isoparaffins and olefins with an acidic alkylation catalyst system comprising a transition alumina which has been previously contacted under substantially anhydrous conditions with a Lewis acid and an amount of free Lewis acid, under alkylation conditions to produce an alkylate stream, and b. separating the alkylate stream from the acidic alumina based alkylation catalyst.

39. The process of claim 38 where the transition alumina is selected from gamma-alumina, eta-alumina, theta-alumina, chi-alumina, kappa-alumina, rho-alumina, lambda-alumina, and mixtures.

40. The process of claim 39 where the transition alumina is selected from gamma-alumina, eta-alumina, and mixtures.

41. The process of claim 38 where the transition alumina additionally contains less than about about 15% by weight of free water.

42. The process of claim 41 where the transition alumina additionally contains less than about 8% by weight of free water.

43. The process of claim 42 where the transition alumina additionally contains 0.5 to 6.0% by weight of free water.

44. The process system of claim 39 where the Lewis acid is BF3.

45. The process of claim 44 where the transition alumina additionally contains less than about 15% by weight of free water.

46. The process of claim 45 where the transition alumina additionally contains less than about 8% by weight of free water.

47. The process of claim 46 where the transition alumina additionally contains 0.5 to 6.0% by weight of free water.

48. The process of claim 38 where alkylation conditions include a temperature in the range of -30°C
to 50°C.

49. The process of claim 38 where the mixture comprises 2-butene and isoparaffin.

50. The process of claim 38 where the contacting step is carried out in the substantial absence of isobutylene.

51. The process of claim 38 where the isoparaffin comprises isobutane.

52. The process of claim 49 where the isoparaffin comprises isobutane.

53. The process of claim 50 where the isoparaffin comprises isobutane.

54. The process of claim 38 where alkylation conditions include a WHSV between 0.5 to 30Ø

55. The process of claim 38 where the ratio of C4-C10 isoparaffins to C3- C5 olefins is in the range of 1:1 to 1000:1.

56. The process of claim 38 including the step of mixing the alkylate stream with other hydrocarbons to produce a gasoline blending component or gasoline.