AU624495B2 - Process for the production of tertiary alkyl ethers and tertiary alkyl alcohols - Google Patents

Description

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2 4 I' OPI DATE 22/10/90 APPLN- ID 53507 PCT NUMBER PCT/US90/01494

PCT

AOJP DATE 29/11/90 INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (51) International Patent Classification 5 I 1 Intrnntinnal Publicatinn Number: WO 90/11268 C07C 43/04, 31/02, 11/02 C07C 41/06, 29/04, 2/10 Al (43) International Publication Date: (43) Internationl Publication Dater 4 October 1990 (04.10.90) (21) International Application Number: (22) International Filing Date: Priority data: 325,742 20 Marc'.

PCT/US90/01494 20 March 1990 (20.03.90) 1989 (20.03,89) (74) Agents: SUNG, Tak, K. et al.; Mobil Oil Corporation, 3225 Gallows Road, Fairfax, VA 22037 (81) Designated States: AT (European patert), AU, BE (Eurot* pean patent), CA, CH (European patent), DE (European patent), DK (European patent), ES (European patent), FR (European patent), GB (European patent), IT (European patent), JP, LU (European patent), NI (European patent), SE (European patent), Published With international search report, Before the expiration of the time limit for amending the claims and to be republished in the event of the receipt of amendments, (71) Applicant: MOBIL OIL CORPORATION [US/US]; 150 East 42nd Street, New York, NY 10017 (US).

(72) Inventors: CHUNG, Harold, Set 2' ueatty Court, Princeton, NJ 08540 JACKSO. Andrew 22 Alta Vista Drive, Princeton, NJ 08540 WU, Margaret, May- Som #7 Warrenton Way, Belle Mead, NJ 08502 (US).

624495 (54) Title: PROCESS FOR THE PRODUCTION OF TERTIARY ALKYL ETHERS AND TERTIARY ALKYL ALCOHOLS (57) Abstract A process for producing lo'ver alkyl tertiary alkyl ethers or tertiary alkyl alcohol, such as methyl tertiary butyl ether (MTBE), methyl tertiary amyl ether (TAME) or tertiary butyl alcohol, wherein the 1-alkene component of the hydro arbon feedstream to an etherification or ,lefin hydration process is separated by selective oligomerization in contact with a reduced chromium on silica support catalyst producing useful hydrocarbons of higher molecular weight, such as gasoline, distillate and ibe range hydrocarbons. It has further been found that separation of the 1-alkene component of the hydrocarbon feedstream can be accomplished in a(n oligomerization process integrated either upstream or downstream of the etherification step.

See back of page IMAB*i'\ WO 90/11268 PCT/US90/01494 -1- PROCESS FOR THE PRODUCTION OF TERTIARY ALKYL EIHERS AND TERTIARY ALKYL AI3OHOLS This invention relates to a new integrated process for the production of lower alkyl tertiary alkyl ether or alkanol.

More particularly, the invention relates to a novel combined process for the selective oligamerization of 1-alkenes and etherification or hydration of iso-olefins in a C 4 hydrocarbon feedstock for the production of methyl tertiary butyl ether (MIBE) ard methyl tertiary amyl ether (TAME).

In recent years, a major technical challenge presented to the petroleum refining industry has been the requirement to establish alternate processes for manufacturing high octane gasoline in view of the regulated requirement to eliminate lead additives as ,ctane enhancers as well as the development of more efficient, higher compression ratio gasoline engines requiring higher octane fuel. To meet these requirements the industry has developed non-lead octane boosters and has reformulated high octane gasoline to incorporate an increased fraction of aromatics. While these and other approaches will fully meet the technical requirements of regulations requiring elimination of gasoline lead additives and allow the industry to meet the burgeoning market demand for high octane gasoline, the economic impact on the cost of gasoline is significant. Accordingly, workers in the field have intensified their effort to discover new processes to manufacture the gasoline products required by the market place. One important focus of that research is a new process to produce high octane gasolines blended with lower aliphatic alkyl ethers as octane boosters and supplementary fuels. C 5

-C

7 methyl alkyl ethers, especially tertiary alkyl ethers such as methyl tertiary butyl ether (MIBE) and tertiary WO 90/11268 PCT/US90/01494 -2amyl methyl ether (TAME), or the corresponding tertiary alcohol, have been found particularly useful for enhancing gasoline octane. Therefore, improvements to the processes related to the production of these ethers are matters of high importance and substantial challenge to research workers in the petroleum refining arts.

It is known that iscbitylene may be reacted with methanol over an acidic catalyst to provide methyl tertiary butyl ether (MrBE) and isoanylenes may be reacted with zethanol over an acidic catalyst to produce tertiary-anmyl methyl ether (TAME).

Similarly, these iso-olefins can be hydrated in the presejce of an acid catalyst to give alcohols. In these processes, a problem of major importance is the separation of the reaction products and separation of unreacted hydrocarbons. For instance, the feedstream to an etherification process can be the C 4 ar4/or C fraction from a fluid catalytic cracking unit containing a full spectrum of isomeric alkanes and alkenes of which only the iso-olefins react with methyl or ethyl alcohol to form the preferred lower alkyl tertiary butyl or tertiary amnyl ether. How unreacted materials are separated and the utility to which they are directed greatly affects process economics.

The catalytic hydration of olefins to provide alcohols and ethers is a well-established art and is of significant camercial importance. Representative olefin hydration processes are disclosed, among others, in U. S. Patents Nos. 2,262,913; 2,477,380; 2,797,247; 3,798,097; 2,805,260; 2,830,090; 2,861,045; 2,891,999; 3,006,970; 3,198,752; 3,810,848; ard 3,989,762.

Olefin hydration employing zeolite catalysts is known.

As disclosed in U. S. Patent No. 4,214,107, lower olefins, in particular propylene, are catalytically hydrated over a crystalline aluminosilicate zeolite catalyst having a silica to alumina ratio of at least 12 and a Constraint Index of from 1 to WO 90/11268 PC'/US90/014 1 -3- 12, acidic ZSM-5 type zeolite, to provide the corresponding alcohol, essentially free of ether and hydrocarbon by-product.

Recently, novel lubricant compositions (referred to herein as HVI-PAO) comprising polyalpha-olefins and methods for their preparation employing, as catalyst, reduced chromium on a silica support have been disclosed in U.S. Patent Nos. 4,827,064 and 4,827,073. The process comprises contacting C 6

-C

20 l-alkene feedstock with reduced valence state chromium oxide catalyst on porous silica support under oligcmerizing conditions in an oligamerization zone whereby high viscosity, high VI (viscosity index) liquid hydrocarbon lubricant is produced having a branch ratio less than 0.19 and a pour point below -15 0 C. The process is distinguished in that internal or iso-olefins are unreactive in the oligamerization; only terminal olefinic groups participate in the coordination catalyzed oligomerization using reduced chromium oxide on silica. Accordingly, the observation has been made that the process is potentially useful for the separation of 1-alkenes from other isawers and for the conversion of 1-alkenes, or alpha-olefins, into useful oligamers.

The present invention provides an integrated process for the preparation of lower alkanol tertiary alkyl ethers, particularly MIBE, or secondary or tertiary alkyl alcohols, utilizing economically advantageous separation of unreactive feedstream components.

It has been discovered that substantial improvenmnts in the process of producing lower alkyl tertiary alkyl ethers, such as methyl tertiary butyl ether (MITE) or methyl tertiary amyl ether (TAME) or the corresponding tertiary alcohols are realized when the 1-alkene component of the hydrocarbon feedstream to an etherification or olefin hydration process is separated by selective oligamerization in contact with a reduced chromium on a silica support catalyst producing useful hydrocarbon of higher molecular weight, such as gasoline, distillate and lube range WO 90/11268 PCT/US90/01494 -4hydrocarbons. It has further been discovered that separation of the 1-alkene component of the hydrocarbon feedstream can be accomplished in an oligrnerization process integrated either upstream or downstream of the etherification or hydration step.

More particularly, an integrated process for the production of oxygenates ocuprising lower alkyl tertiary alkyl ethers and tertiary alkyl alcohols plus higher molecular weight olefins from C 4 hydrocarbons has been found, the process camprising the steps of: a) contacting a lower alkanol or water feedstream and a

C

4 hydrocarbon feedstream rich in iso-olefins with an acid catalyst in a reaction zone under etherification or hydration conditions to produce an effluent stream comprising lower alkyl tertiary alkyl ethers or tertiary alkyl alcohols and unreacted

C

4 hydrocarbons containing l-alkene components; b) separating the effluent stream and recovering the ether or tertiary alcohol component thereof; c) passing the effluent stream component containing l-alkene to an oligomerization zone in contact with reduced chromium oxide on a silica support catalyst under oligcmerization conditions whereby the l-alkene is oligamerized to the higher molecular weight olefins; and d) separating and recovering the olefins.

In the drawings, Figure 1 is a block diagram illustrating the instant invention embodying oligamerization downstream of etherification.

Figure 2 is a block diagram illustrating the instant invention embodying oligcrierization upstream of etherification.

The instant invention utilizes the unique capability of the oligamerization process described herein, referred to as the HVI-PAO process, to selectively oligacerize l-alkene without oligamerizing those alkenes containing only internal olefin bonds. The process can, therefore, preferentially convert WO090/11268 PCT/US9O/OI 494 1-alkenes in a mixture of hydrocarbons containing other unsaturated olefinic isomTers and alkanes to Produce higher polymers of 1-alkene, otherwise referred to as polyalpha-olefiris, in the form. of valuable higher moilecular weight olef ins. These oligamers .Xith olefinic unsaturation can be used as starting material for detergents, additives and manry other chemicals.

Followiing hydrogenation by conventional processes well k~nown in the art, they also can yield useful gasoline, distillate and lube range products. When this capability of the HVI-PAC) oligomerization. process is integrated with iso-olef in etherification or olefin hydration processes using mixed hydrocarbon feedstock such as from~ an FC (fluid catalytic cracking) unsaturated gas plant containing 1-alkene, the 1-alkene is preferentially separated, enhancing the performance of the etherification or hydration processes, such as IMM'B or tertiary butyl alcohol (TBA) production.

In the present invention oxygenates carprising lower alkanol tertiary alkyl ethers and tertiary alcohols Plus higher mo~lecular weight olef ins from C 4 hydrocarbons are produced fran the same feedstream. The oxygenates are produced by either etherification or hydration of olef ins while the higher molecuaar weight olefins are produced by oligcmerization of 1-alkene Y-y the method described herein. Thbe term "oxygenates" or "oxygenate$' as used herein refer-s to C 1 -C 8 lower aliphatic, acyclic alcohols or alkanol and symmetrical or unsymmetrical C 2 ethers.

Olefins suitable for use as starting material in the HVI-PAO process which are preferentially oligzmerize,-I when included in a feedstrein to an iso-olefin etherification or hydration process include those olef ins containing frcin 2 to carbon atcus such as ethylene, prx41ylene, 1-3-Autene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene and 1-tetradecene and branched chain isaners such as 4-methyl-l-entene. Also suitable for use are refinery olefinivv hydrocarbon feedstocks or effluents WO 90/11268 PCT/US90/01494 6containing alphaolefins. Typically, such feedstock will also be rich in C4+ iso-olefins and other olefin isaomers and generally is comprised of 1-butene, 2-butene, iscbutene, 1-pentene, 2-pentene and isoamylene and higher hydrocarbons.

The alpha-olefin oligamers are prepared by oligamerization reactions in which a major proportion of the double bonds of the alpha-olefins are not iscuerized. These reactions include alpha-olefin oligamerization by supported metal oxide catalysts, such as Cr compounds on silica or other supported IUPAC Pariodic Table Group VIB copxounds. The catalyst most preferred is a lower valence Group VID metal oxide on an inert support. Preferred supports include silica, alumina, titania, silica alumina, magnesia and the like. The support material binds the metal oxide catalyst. Por us substrates having -7 a pore opening of at least 40 x 10 mm (40 angstrcms) are preferred.

The support material usually has high surface area and large pore volumes with average pore size of 40 to 350 x 10 mm to 350 angstroms.) The high surface area is beneficial for supporting large amounts of highly dispersive, active chrcmim metal centers and to give maximum efficiency of metal usage, resulting in very high activity catalyst. The support should have large average pore openings of at least 40 x 10 7 mm angstroms), with an average pore opening of >60 to 300 x 10 m to 300 angsttron) being preferred. This large pore opening will not impose any, diffusional restriction of the reactant and product to and away from the active catalytic metal centers, thus further optimizing the catalyst productivity. Also, for this catalyst to be used in fixed bed or slurry reactcr and to be recycled and regenerated many times, a silica support with good physical strength is preferred to prevent catalyst 'particle attrition or disintegration during handling or reacvion.

WO 90/11268 PCT/US90/01494 -7- The supported metal oxide catalysts are preferably prepared by impregnating metal salts in water or organic solvents onto the support. Any suitable organic solvent known to the art may be used, for example, ethanol, methanol, or acetic acid. The solid catalyst precursor is then dried and calcined at 200 to 900 0 C by air or other oxygen-containing gas. Thereafter the catalyst is reduced by any of several various and well known reducing agents such as, for example, CO, H 2 NH", H 2 S, CS 2 aLSCTL, C 3

SSCH

3 metal alkyl containing compounds such as R3Al,

R

3 B,RM, RLi, R 2 Zn, where R is alkyl, alkoxy, aryl and the like.

Preferred are CO or H 2 or metal alkyl containing compounds.

Alternatively, the Group VIB metal may be applied to the substrate in reduced form, such as CrII componds. The resultant catalyst is very active for oligcerizing olefins at a temperature range from below roam temperature to about 250°C at a pressure of 10 kPa (0.1 atmosphere) to 34600 k pa (5000 psi.) Contact time of both the olefin and the catalyst can vary frcm one second to 24 hours. The catalyst can be used in a batch type reactor or in a fixed bed, continuous-flow raactor.

In general the support material may be added to a solution of the metal compounds, e.g, acetates or nitrates, etc., and the mixture is then mixed and dried at room temperature. Te dry solid gel is purged at successively higher temperatures to Q46© for a period of 16 to 20 hours.

Thereafter the catalyst is cooled, under an inert atmosphere to a temperature of 250 to 450°C and a stream of pure reducing agent is, contacted therewith for a period when enough CO has passed Sthrough to reduce the catalyst as indicated by a distinct color change from bright orange to pale blue. Typically, the catalyst is treated with an amount of CO equivalent to a two-fold stoichiometric excess to reduce the catalyst to a lower valence CrII state. Finally, the catalyst is cooled to room temperature ard is ready for use.

WO 90/11268 PCr/US90/01494 -8- The following examples of the HVI-PAD process are presentei merely for illustration purposc,; and are not intended to linit the scope of the present invention which integrates the HVI-PAO process with etherification.

R.1 le 1 Catalyst Preparation and Activation Procdure 1.9 grams of duramium (II) acetate (Cr2(oCoC) 420) (5.58 mole) (commercially obtained) is dissolved in 50 ml of hot acetic acid. Then 50 granms of a silica gel of 8-12 mresh size, a surface area of 300 m2/g, and a pore volume of 1 mn2/g, also is added. lMost of the solution is absorbed by the silica gel. The final mixture is mixed for half an hour on a rotavap at roan temperature and dried in an open-dish at roan temperature. First, the dry solid (20 g) is purged with N 2 at 250 0 C in a tube furnace. The furnace temperature is then raised to 400 0 C for 2 hours. The temperature is then set at 600 0 C with dry air purging for 16 hours. At this tire the catalyst is cooled under N 2 to a temperature of 300 0

C.

Then a stream of pure CO (99.99% fran Matdheson) is introduced for one hour. Finally, the catalyst is cooled to roan temperature under N2 and ready for use.

Exanle 2 The catalyst prepared in Example 1 (3.2 g) is packed in a 9.5 mm stainless steel tubular reactor inside an 12 blanketed dry box. The reactor under N 2 atmosphere is then heated to 150 0 C by a single-zone Lindberg furnace. Prepurified 1-hexene is pumped into the reactor at 1068 kPa (140 psi) and ml/hr. The li\uid effluent is collected and stripped of the unreacted starting material and the low boiling material at 7 Pa (0.05 m Hg) The residual clear, colorless liquid has viscositie. and VI 's uitable as a lubricant base stock.

WO90/11268 PC/US90/01494 -9- L Preun 1 2 3 hr. 2 3.Z 5.5 21.5 (Time on Stream) DLube Yield, wt% 10 41 74 31 Viscosity, m2/s at 400( 208.5 123.3 104.4 166.2 100 0 C 26.1 17.1 14.5 20.4 VI 159 151 142 143 Example 3 A commercial chrae/silica catalyst which contains 1% Cr on a large-pore volume synthetic silica gel is used. The catalyst is first calcined with air at 800 0 C for 16 hours and reduced with C) at 300 0 for 1.5 hours. Then 3.5 g of the catalyst is packed into a tubular reactor and heated to 1000C under the N 2 atmosphere. 1-Hexene is pmped through at 28 ml per hour at 101 kPa (1 atmosphere.) The products are collected and analyzed as follows: gaml C D ,E F T.O.S.I hrs. 3.5 4.5 6.5 22.5 Wbe Yield, 73 64 59 21 Viscosity, 1m2/s (cS) at 400C 2548 2429 3315 9031 1009 c- 102 151 197 437 VI 108 164 174 199 These runs show that differe-nt cr on a silica catalyst support are also effective for oligamrerizing olefins and can be used in the instant invention.

In the preferred embodiments of this invention, a lower alcohol such as methanol, ethanol, l-prrpanol or iscpropano1, but preferably methanol, is reacted with hydrocarbon feedstock such WO 90/11268 PC'r/US9O/oI 494 as C 4 and C+feedstock containing olefins, particularly iso-olef ins, to produca- meth-yl tertiary alkyl ethers, particularly miethyl tertiary butyl ether and methyl. tertiary anyl ether. Alternatively, the ol'f2ins may be hydrated by reaction with water to form the correspon~ding alcohol sixh as tertiary butyl. alcohol, 2-)Rutanol, 2-pentanol, 3-penitanol, 3-rethyl, 2-butanol and the like. In the etterJification reaction, the alkanol, or lower alcohol such as methanol, is germrally Present in an excess amount between 2 to 100 wt%, based upon iso-olef ins. Excess methanol mreans excess mrethanol above the StOichian'Mtric equivalent aimount to convert isoolef ins in the hydrocarbon feedstream to methyl tertiary alkyl ethers.

Followqing the etherification reaction, the etherification reaction effluent stream, VKiich ccuprises unreacted methanol, hydrocarbons including a major portion of C 4 hydr,:carbons and methyl tertiary alkyl ethers, are separated according to fractionation and extraction techniques well known to those skilled in the art.

Methanol ray be readily obtained from coal by %da-sification to synthesis gas and conversion of the synthesis gas to Msthanol by well-established industrial proceses. As an alternative, the mrethanol may be obtained fr= natural gas by other conventizial processes, such as steam reformbing or partial oxidation to make the intermediatua synqas. crude methanol from such processes usually contains a significant amount of water, usually in the range of 4 to 20 wt%. The cicherification catalyst enl 4 is preferably an ion enr~hange resin in the hydrogen form; how'ever, any suitable acidic catalyst may be en~loyed.

Varying degrees of success ava obtained with acidic solid c"ilysts; such as) sulfonic: ;'cid resinc, phosphoric acid modified kieselguhr, silica a ,umina and acid zeolites. Ty~jpical hydrocarbon feedstock materialm for etherification reactions includie olefinic streams, such as rx' light naphtha and bqtenes WO 90/11268 PCT/US90/01494 -11ridch in iso-olefins. These aliphatic streams are produced in petroleum refineries by catalytic cracking of gas oil or the like.

The reaction of methanol with isobutylene ard isoamylenes at moderate conditions with a resin catalyst is known technology, as provided by R. W. Reynolds, et al., The Oil and Gas Journal, June 16, 1975, and S. Pecci and T. Floris, Hydr Processing, December 1977. An article entitled "qTBE and TAME A Good Octane Boosting COmbo," by J.D. Chase, et al., The Oil and Gas Journal, April 9, 1979, pages 149-152, discusses the technology. A preferred catalyst is a bifunctional ion exchange resin which etherifies arndl isarizes the reactant streams. A typical acid catalyst is Amberlyst 15 sulfonic pcid resin.

MIBE and TAME are known to be high octane ethers. The article by J.D. Chase, et al., Oil and Gas Journal, April 9, 1979, discusses the advantages one can achieve by using these materials to enhance gasoline octane. Tha octane blending numbeof MTBE when 10% is added to a base fuel (R+O 91) is about 120.

For a fuel with a low motor rating (M+O 83) octane, the blending value of MBE at the 10% level is about 103. On the other hand, for an of 95 octane fuel, the blending value of MBE is about 114.

Processes for producing and recovering MTBE and other methyl tertiary alkyl ethers fram C 4

-C

7 isoolefins are known to those skilled in the art, such as disclosed in U.S. Patents 4,514,776 (Osterburg, et al.) and 4,603,225 (Colaianne et al.).

Various suitable extraction and distillation techniques are known for recovering ether and hydrocarbon streams from etherification effluent.

As noted and referenced herein before, processes are also well known in the art for the production of alcohols by hydration of olefins in contact with acidic catalyst.

WO 90/11268 PCI'/US9O/01494 Tertiary alcohols produced thereby are known to have high c-tane numbers.

Referrin? to Figure 1, one o~bdiment of the instanrt invention 1S presented integratarg the MIV-PAO process daw~nstream of the etherification proes producing 1WE or a hydration process producing TBA.. A C 4 or C+stream 110 containing l-alkene andi iso-4yutene is fed to an etherification or hye tio zone 115 together with nthanol or water feedstream 120. The tUerf ication or hydration effluent is separated to provide a raffinate stream 125 containing hydrocarbons ancluding 1-alkene while 1MBE is recovered in stream 130 in the case of etheriCication and TBA is recovered in the case of hydratio~n.

The rafflnate stream 125 is passed to HVI-PAD process oligcrerization zone 135 wherein 1-alkene hydrocarbons are selectively converted to higher molecular olefins and, in partimi",ar, poly-l--butene liquids. The effluant fromi the oligcmP-rization zone is separated to recover oligaceric olefins 1110 including poly-1-butene and a stream 145 czntaining unreacted

C

4 or 0 4 hydrocarbons.

4 Referring to Figure 2, another embodient of the instant invention is presented where the HVI-PAO) process is integrated upstream of etherification or hydration unit. In this emxbodimrent the C 4 or C 4 feedstream 210 containing 1-alkene and iso-olef ins is fed to the oligcmerization zone 215. The effluent is separated ar- a raffinate stream 220 containing unreacted iso-olef ins is passed to etherification or hydration zone 225 in conjunation 4 with mth-anol or water feedstream 230 while oligcumerization product is recovered in stream 235. The effluent frm~ the etherification or hydration zone is separated to provide MTBE or ,M 240 and ureacted. hydrocarbons 245.

In Figure 1, the raffinate stream.,frui MMfE or other etherification units, coatzining 2-buxtenes and/or butxanes, is reacted over Cr/SiO 2 type catalysts to g ive useful liquid WO90/11268 PCT/US90/01494 -13products. The residual C 4 stream, rich in 2-butene and/or butanes, can be used in alkylation units, or starting material for butadiene or iscmerization reztor to upgrade 2-butene into mixed butenes.

In Figure 2, the mixel C4 stream is first reacted over an Cr/Sio 2 type catalyst to selectively remave 1-xbutene. The raffinate is then fed into a TBE or etherification unit to remove i-butene. The residual stream is rich in 2-butene and/or butarMes.

In both ebodients, the I-butene is selectively removed and converted into useful liquid products over a Cr/Sio 2 catalyst. The residual 2-butene streanms, usually of little use and low value, can be iscamerized into highor-value 1- or iso-butenes, can be used in alkylation units or dehydrogenated into butadiene. These operations separate 1- and 2-butenes without omplicated distillation or sorption techniques.

In both embodiments the liquid oligacner product can be used as a starting material for additives, lubricants, gasoline or distillates.

The follcing examples illustrate the novel selectivity of the oligamerization process.

Example 4 Eleven grams of 1-hexene and 10 g 2-hexenes are mixed with 1.5 g of an activated Cr on silica catalyst, prepared by calcinirq a catalyst containing 0.91% Cr and 2.32% Ti on silica at 60 0 0C with air follwed by reduction with CO at 30C 0 C. The reaction is traced by GC which data demonstrates that 1-hexene can be selectively reacted away in the presence of other hexenes.

The contents of 2-hexenes remained constant throughout the reaction. 2-hexenes are unreactive.

WO 90/!11268 PCr/US90/01494 -14- Examrple A catalyst, 3 grams, containing 3 wt% Cr on silica gel, calcined at 600 0 C with air for 16 hours and reduced with 0O at 350 0 C for one hour, is packed in a 9.5 m stainless steel tube reactor. 1-Butene is fed through the reactor at 160 0 C, 2520 kPa 1350 psi) and MHSV of 2. After 21.5 hours reaction timare, 134 grams of liquid product is collected. The conversion of 1-butene to liquid is 100%. The liquid product is fractionated to give 3 fractions: fraction 1, boiling up to 140oC/atm, 15.3 wt%, mostly octenes; fraction 2, boiling up to 1600C/13 Pa(0.1Jmm Hg), 56%, nmostly C12 to C24 olefins; Fraction 3, residual, 28.7 wt%, with the following viscametric properties, V100oC 28.65 m2/s (28.65 CS), V@40oC 411.37 Nm/s (411.37 cS), VI 96 Example 6 Similar to Exaple 5, except reaction tenperature is 123 0 C. The liquid ield from 1-butene is 100%. The liquid product is fractionated to give the following fractions: fraction 1, boiling up to 1400C/atm, 0.4 wt%.

fraction 2, boiling up to 1600C/13.3 Pa (0.1mun Hg), 23.6 wt%, nmostly C12 to C24 olefins fraction 3, residual, 76wt%, with the following viscometric properties VM0oc 70.13 nMM/s (70.13 cS), V@400C 1904.92 nn /s (1904.92 cS), VI 89.

While the invention has been described by specific exanple; and enbodiments, there is no intent to limit the inventive concept except as set forth in the following claims:

Claims (21)

1. An integrated process for the productiocn of lower alkyl tertiary alkyl ethers and higher molecular weight olefins froman C 4 hydrocarbons containing alpha-olefins and iso-olefins ccprising the steps of: a) contacting a C-C 8 lower alkano1 feedstream and a feedstream coprising the C4+ hydrearbons cntaining isobutenes and 1-alkenes with an acid etherification catalyst in an etherification zone uder etherification conditions to prodce an effluent stream comprising lower alkyl tertiary ayl ethers and unreacted c hydrocarbons containing the 1-alkene ctmponents; b) separating the effluent stream and recovering the ether crmponent thereof; c) feedinxr the effluent stream ccaponent containing 1-alkene to an oligamerization zone in contact with reduced chramium oxide on silica support catalyst under oligamerization conditions at a temperature of 90oc to 2500C to oligamerize the d -alkene to higher molecular weight olefins; wherein the chrtmium catalyst on silica support has been treated by oxidation at a temperature of 200 to 9000 in the presence of an oxidizing gas and then treatment with CO reducing agent to reduce the catalyst to a lower valence state; and d) separating and recovering the higher molecular weight olefins.

2. The process of claim 1 wherein the lower alkyl tertiary alkyl ether omprises methyl tertiary butyl ether and/or methyl tertiary amyl ether.

3. The process of claim 1 wherein the hydrocarbon feedstream comprises l-butene, 2-butene, iso-butene and butane.

4. The process of claim 1 wherein the C4+ feedstream contains isoamylene. The process of claim 1 wherein the lower alkanol WO 90/i26e PCT/US90/01494 -16- comprises between 2 and 100% stoichiacietric excess of lower alkanol selected frcn methanol, ethanol, 1-propanol and isopropanol.

6. The process of claim 1 wherein the hydrocarbon feedstream camprises C 4 olef 1 ins from an FC unsaturated gas plant.

7. The process of claim 1 wherein the high molecular weight olefin conmprises polymers and copolymers of C4+ 1-alkene. S. The process of claim 1 wherein the polymer camprises poly-1-butene.

9. The process of claim 1 wherein the oligamerization conditions comprise temperature between 90 and 250 0 C. An integrated process for the production of lower alkyl tertiary alkyl ether and higher molecular weight olefins fran lower alkanol and C 4 hydrocarbons containing alpha-olefins and iso-olefins, comprising: a) contacting a feed stream omprising the C4+ hydrocarbons with reduced chrnium oxide on silica support catalyst under oligomerization conditions in an oligerization zone whereby 1-alkene component of the feedstream is oligamerized to produce an effluent stream containing higher molecular w-ight olefins and unreacted C 4 hydrocarbons; b) separating and recovering the higher molecular weight olefins; c) passing the unreacted hydrocarbons and lower alkanol feedstream to an etherification zone in contact with acidic etherification catalyst under etherification conditions whereby an effluent stream is produced containing lower alkyl tertiary alkyl ether; d) separating and recovering the ether.

11. The process of claim 10 wherein the lower alky, tertiary alkyl ether comprises methyl tertiary butyl ether and/or methyl tertiary amyl ether. WO 90/11268 PCT/US90/01494 -17-

12. The process of claim 10 wherein the hydrocarbon feedstream carprises 1-butene, 2-butene, iso-butene and butane.

13. The process of claim 10 wherein the C4+ feedstream contains isoamylen.

14. The process of claim 10 wherein the lower alkanol carrprises between 2 and 100% stoichiiacmetric excess of lower alkanol selected from methanol, ethanol, 1-propanol and isopropanol. The process of claim 10 wherein the hydrocarbon feedstream comrprises C 4 olefins franom an F= unsaturated gas plant.

16. The process of claim 10 wherein the higher molecular weight olefin crmprises polymers and copolymers of C l-alkene.

17. The process of claim 10 wherein the polymer ccuprises poly-1-butene.

18. The process of claim 10 wherein the oligaarization conditions onmprise terperature between 90 and 250 0 C.

19. The process of claim 1 or 10 wherein the higher molecular weight olefin is hydrogenated to produce saturated hydrocarbon. An integrated process for the production of tertiary alkyl alcohols and higher molecuilar weight olefins frm C4+ olefinic hydrocarbons contaning alpha-olefins and iso-olefins camprising the steps of: a) contacting a water feedstream and a feedstream ccmprising the C 4 hydrocarbons with an acidic olefin hydration catalyst in a hydration zone under olefin hydration conditions whereby an effluent stream is produced comprising C 4 tertiary alkyl alcohol and unreacted C 4 hydrocarbons containing 1-alkene components; b) separating the effluent stream and recovering the alcohol camponent thereof; WO 90/11268 PCT/US90/01494 -18- c) passing the effluent stream component containing l-alkene to an oligcamerization zone in contact with reduced chranium oxide on silica support catalyst under oligamerization conditions whereby the 1-alkene is .oligamerized to the higher molecular weight olefins; and d) separating and recoverirng the higher molecular weight olefins.

21. The process of claim 20 wherein the alcohol comprises tertiary butyl alcohol.

22. The process of claim 20 wherein the hydrocarbon feedstream comprises 1-butene, 2-buxtene, iso-butene and butane.

23. The process of claim 20 wherein the C4+ feedstream contains isoamylene and the alcoiol comprises isoamyl alcohol.

24. The process of claim 20 wherein the high molecular weight olefin comprises polymers and copolymers of C4+ 1-alkene. An integrated process for the production of tertiary alkyl alcohol and higher molecular weight olefins fran C4 olefinic hydrocarbons containing alpha-olefins and iso-olefins, camprising: a) contacting a feedstream omrprising the C4 hydrocarbons with reduced chromaium cxide on silica support catalyst under oligamerization corditions in an oligauerization zone whereby 1-al)-hne component of the fedvstream is oligomerized to produce an effluent stream containing higher molecular weight olefins and unreacted C 4 hydrocarbons; b) separatir- and recovering the higher molecular weight olefins; c) passing the unreacted hydrocarbons and water feedstream to an olefins hydration zone in'contact with acidic catalyst under olefins hydration conditions whereby an effluent stream is produced containing tertiary alkyl alcohol; d) separating and recovering the alcohol.

26. The process of claim 25 wherein the alcohol comprises tertiary butyl alcohol.

27. A process according to claim 1 substantially as hereinbefore defined with reference to any one of Examples 2 to 6. DATED: 17 March 1992 S PHILLIPS ORMONDE FITZPATRICK Attorneys for: S MOBIL OIL CORPORATION e *A*M *4 9 19 L