WO1998006687A1 - Procede de production d'ether methyltertiobutylique - Google Patents

Procede de production d'ether methyltertiobutylique Download PDF

Info

Publication number
WO1998006687A1
WO1998006687A1 PCT/US1997/007171 US9707171W WO9806687A1 WO 1998006687 A1 WO1998006687 A1 WO 1998006687A1 US 9707171 W US9707171 W US 9707171W WO 9806687 A1 WO9806687 A1 WO 9806687A1
Authority
WO
WIPO (PCT)
Prior art keywords
butene
reactor
distillation column
isobutylene
column reactor
Prior art date
Application number
PCT/US1997/007171
Other languages
English (en)
Inventor
Thomas P. Hickey
Lawrence A. Smith, Jr.
Original Assignee
Catalytic Distillation Technologies
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Catalytic Distillation Technologies filed Critical Catalytic Distillation Technologies
Priority to AU28181/97A priority Critical patent/AU2818197A/en
Publication of WO1998006687A1 publication Critical patent/WO1998006687A1/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C41/00—Preparation of ethers; Preparation of compounds having groups, groups or groups
    • C07C41/01—Preparation of ethers
    • C07C41/05—Preparation of ethers by addition of compounds to unsaturated compounds
    • C07C41/06—Preparation of ethers by addition of compounds to unsaturated compounds by addition of organic compounds only
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
    • B01D3/009—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping in combination with chemical reactions
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C41/00—Preparation of ethers; Preparation of compounds having groups, groups or groups
    • C07C41/01—Preparation of ethers
    • C07C41/34—Separation; Purification; Stabilisation; Use of additives
    • C07C41/40—Separation; Purification; Stabilisation; Use of additives by change of physical state, e.g. by crystallisation
    • C07C41/42—Separation; Purification; Stabilisation; Use of additives by change of physical state, e.g. by crystallisation by distillation
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/10—Process efficiency

Definitions

  • the present invention relates to an improved, integrated process for the production of alkyl tertiary alkyl ethers, such as methyl tertiary butyl ether (MTBE), by reacting isoalkene with alcohol. More particularly, the invention relates to a process wherein a stream containing isoalkene and normal alkenes is treated to remove dienes and/or isomerize normal alkenes to separate the higher boiling normal alkenes from the isoalkene, thereby concentrating the isoalkenes.
  • alkyl tertiary alkyl ethers such as methyl tertiary butyl ether (MTBE)
  • Methyl tertiary butyl ether (MTBE) , methyl tertiary amyl ether (TAME) and the ethyl analogues thereof are useful as a component for improving the octane of gasolines and have commonly been prepared by the acid catalyzed reaction of the appropriate alcohol with isobutene or isoa ylene. Examples of such a process are disclosed in U.S. Pat. Nos. 4,039,590 and 4,198,530.
  • the feed stocks for MTBE are isobutylene and methanol.
  • Isobutylene may be obtained by the dehydration of tertiary butyl alcohol or by the skeletal isomerization of linear butenes.
  • the preferable source of isobutylene and isoamylenes for many refiners is the C4 raffinate obtained from a catalytic cracker because it is available on site.
  • the C 4 and C 5 raffinate streams are comparatively dilute or lean sources of isoalkene and the entire stream is conventionally fed to the etherification reactor.
  • the non-isoalkene components of these streams including paraffins such as butane and isobutane and mixed linear butenes, normal pentenes, isopentanes and pentane are essentially inert under etherification conditions but do increase the hydraulic load on the reactors.
  • the C 4 raffinate stream from a catalytic cracker typically consists of about 50 weight % paraffins, 35 weight % mixed linear butenes and only 15 weight % isobutylene. Nonetheless, this raffinate stream is an important source of isobutylene for MTBE production. Accordingly, an improved process to use dilute isoolefins for the production of ethers would be useful .
  • hydroisomerization is a process used to upgrade C 4 streams, usually from fluid catalytic cracking units.
  • butadiene contaminating the feed is hydrogenated to butenes, and the normal butenes are isomerized to the equilibrium mixture which is predominately butene-2.
  • the advantage of that process is to remove butadiene which causes the loss of acid used in the alkylation process and improvement of the alkylate octane number in HF alkylation by using mostly butene-2 in the feed rather than butene-l.
  • Double bond isomerization can be carried out during the hydrotreating.
  • palladium hydrogenation catalysts are known and used for the butene-1 to butene-2 isomerization. Isomerization occurs only after hydrogenation.
  • Hydroisomerization has been practiced in a catalytic distillation column, particularly the bond shift of butene- 2 to butene-1, as illustrated in commonly assigned U.S. Pat. No. 5,087,780.
  • the preferred catalyst structure for the hydroisomerization reaction is a more open mesh like structure as disclosed in commonly assigned U.S Pat. Nos. 5,266,546; 5,348,710; and 5,431,890.
  • the isoalkene containing stream for reaction in an etherification is first hydrotreated in a hydrotreating zone by feeding a hydrocarbon stream containing isoalkene and highly unsaturated compounds which comprise diolefins and/or acetylenes along with a hydrogen stream at an effectuating hydrogen partial pressure of at least about 0.1 psia to less than 70 psia, preferably less than 50 psia to a distillation column reactor containing a hydrogenation catalyst which is a component of a distillation structure and selectively hydrogenating a portion of the highly unsaturated compounds and concurrently separating by fractionation an overhead stream having a higher concentration of the isoalkene than the hydrocarbon stream and feeding the overhead stream to an etherification reactor with alcohol to produce ether.
  • FIG. 1 is a process flow diagram in schematic form of the preferred embodiment of the invention.
  • the hydrocarbon stream typically comprises C to Cg aliphatic compounds, which may be narrow cuts or include a range of carbon content. Refining techniques are such that very accurate cuts of carbon groups can be achieved.
  • the feeds are C 4 and C5 cuts in which the diene and/or acetylene impurities, normal -alkenes, -alkanes and the isoalkanes correspond in carbon number to isoalkene.
  • the catalytic material employed in the hydrogenation process is in a form to serve as distillation packing.
  • the catalytic material is a component of a distillation system functioning as both a catalyst and distillation packing, i.e., a packing for a distillation column having both a distillation function and a catalytic function.
  • the reaction system can be described as heterogenous since the catalyst remains a distinct entity.
  • Any suitable hydrogenation catalyst may be used, for example Group VIII metals of the Periodic Table of Elements as the principal catalytic component, alone or with promoters and modifiers such as palladium/gold, palladium/silver, cobalt/zirconium, nickel preferably deposited on a support such as alumina, fire brick, pumice, carbon, silica, resin or the like.
  • a preferred catalytic material comprises palladium oxide, preferably 0.1 to 5.0 weight %, supported on an appropriate support medium such as alumina, carbon or silica, e.g., 1/8" alumina extrudates.
  • an appropriate support medium such as alumina, carbon or silica, e.g., 1/8" alumina extrudates.
  • the particulate catalyst material is disposed within a porous plate or screen to contain the catalyst and provide distillation surfaces, in the form of a wire mesh structure, such as a wire mesh tubular structure or any other similar structure.
  • a catalyst suitable for the hydroisomerization process is 0.5% PdO on 1/8" AI 2 O 3 (alumina) extrudates, hydroisomerization catalyst, supplied by Engelhard Industries.
  • the catalyst is believed to be the hydride of palladium which is produced during operation.
  • the hydrogen rate to the reactor must be sufficient to maintain the catalyst in the active form because hydrogen is lost from the catalyst by hydrogenation, especially when butadiene is contained in the feed.
  • the hydrogen rate must be adjusted such that there is sufficient to support the butadiene hydrogenation reaction and replace hydrogen lost from the catalyst but kept below that required for hydrogenation of butenes and to prevent flooding of the column which is understood to be the "effectuating amount of hydrogen" as that term is used herein.
  • the mole ratio of hydrogen to butadiene contained in the C 4 hydrocarbon fed to the fixed bed of the present invention will be about 1.0/1.0 to 10/1, preferably 2/1 to 6/1.
  • a preferred catalyst structure for use in the distillation column reactors for the present hydroisomerizations comprises flexible, semi-rigid open mesh tubular material, such as stainless steel wire mesh, filled with a particulate catalytic material
  • the hydrotreating is carried out in a catalyst packed column which can be appreciated to contain a vapor phase and some liquid phase as in any distillation and is described in detail in commonly assigned U.S. patent application Serial No. 08/163,311 filed 12/08/93 and incorporated herein.
  • the distillation column reactor is operated at a pressure such that the reaction mixture is boiling in the bed of catalyst.
  • the present process operates at overhead pressure of said distillation column reactor in the range between 0 and 350 psig, preferably 250 or less and temperatures within said distillation reaction zone in the range of 40 to 300°F, preferably 110 to 270°F at the requisite hydrogen partial pressures.
  • WHSV feed weight hourly space velocity
  • the preferred catalysts for the etherification is an acidic cation exchange resin such as Amberlyst as manufactured by Rohm & Haas Co. Concentration of the isoalkene in the feed to the etherification will enhance the operation of any of the known reaction systems, e.g, fixed bed straight pass, fluidized beds, ebulating bed and catalytic distillation.
  • a preferred structure for use in a catalytic distillation etherification is to dispose the resin beads in pockets of a cloth belt which is then wound into a spiral with demister wire which supports and separates the belts in the column.
  • Such a system has been described in commonly assigned U.S. Pat. Nos. 4,215,011; 4,232,177; 4,242,530; 4,302,356; 4,307,254 4,336,407; 4,439,350 and 4,482,775.
  • U.S. Pat. Nos. 4,443,559 and 4,250,052 disclose a variety of catalyst structures for this use and are incorporated herein.
  • Typical conditions for the catalytic distillation MTBE reaction include catalyst bed temperatures of about 150-170 °F, overhead pressures of about 90-110 psig and equivalent liquid hourly space velocities of about 1.0 to 2.0 hr- 1 .
  • methanol and C *s are first fed to a down flow guard bed reactor operated as a boiling point reactor wherein considerable etherification occurs prior to the distillation column reactor.
  • the operation of the boiling point reactor for etherification is detailed in U.S. Pat. No. 4,950,803 which is herein incorporated by reference.
  • An additional feature of the process is that a portion of the mono-olefins contained within the stream or produced by the selective hydrogenation of the diolefins may be isomerized to more desirable products. Isomerization can be achieved with the same family of catalysts as used in hydrogenations. Generally the relative rates of reaction for various compounds are in the order of from faster to slower:
  • the normal mono-olefins can be recovered or preferably subjected to skeletal isomerization to produce more of the isoalkene.
  • the product from the skeletal isomerization can be combined with the feed to the etherification or returned to the hydrotreating zone for separation of the isoalkene and further double bond isomerization of normal mono- olefin.
  • the hydrotreating/isomerization of the C 4 stream containing butanes, normal butenes, isobutylene and butadiene in a distillation column reactor containing a hydroisomerization catalyst in the form of a catalytic distillation structure is preferably operated to reduce butadiene content and isomerize the butene-1 to a higher boiling butene-2.
  • the higher boiling butene-2 is concurrently separated by fractional distillation and removed as bottoms.
  • the overheads thus enriched by the removal of the original butene-2 and the converted butene-1, is fed to an etherification reactor preferably comprising a second distillation column reactor containing an acid etherification catalyst in the form of a catalytic distillation structure to produce MTBE.
  • the MTBE is concurrently separated as bottoms from the second distillation column reactor with unreacted methanol and inerts (essentially the butanes and butene-1 not isomerized during the hydrotreating) removed as overheads.
  • the butene-1 may be used as feed to a cold acid alkylation unit for the production of the important gasoline component 2,2,4 tri-methyl pentane (isooctane) or as a co-monomer.
  • the bottoms from the first distillation column reactor containing the butene-2 may be recovered or is preferably passed on to a skeletal isomerization reactor containing a skeletal isomerization catalyst, such as a gamma alumina, for conversion to isobutylene.
  • a skeletal isomerization catalyst such as a gamma alumina
  • the preferred catalysts for the skeletal isomerization is ZSM 35 and its isotypes, such as ferrierite.
  • Other zeolitic molecular sieves such as ZSM-22 and ZSM-23 will carry out the isomerization although less effectively.
  • aluminas having a surface area of at least about 100 m 2 /g, preferably the surface area is greater than 150 m 2 /g.
  • Techniques of preparing such alumina catalysts are well known in the art. Examples of such alumina catalysts include eta-alumina and gamma- alumina.
  • aluminas having high purity, particularly with respect to their content of alkali metals are preferred.
  • the aluminas should contain less than about 0.1 weight percent alkali metal, preferably less than 0.05 weight percent, based on the weight of the catalyst.
  • the alkali metals include lithium, sodium, potassium, rubidium, and cesium.
  • the aluminas generally are less efficient than the specified zeolites and tend to coke up faster.
  • Such catalysts can be employed in the manner known in the art for the skeletal isomerization of olefins to more highly branched olefins. Such catalysts are particularly suitable for the isomerization of n-olefins having 4 to 10 carbon atoms per molecule or mixtures thereof. Mixtures comprising olefins and essentially inert hydrocarbons can also be treated according to this invention to provide an isomerized olefinic product in admixture with the inert hydrocarbons. Particularly useful isomerizations with such catalysts are conducted on feed-streams of gasoline, especially catalytically cracked gasoline. This isomerization with such catalysts can be conducted under any conditions sufficient to produce the desired isomers.
  • the isomerization is conducted at a temperature in the range of about 315°C. to about 510"C., preferably about 343 " C. to about 454 °C.
  • Isomerization is generally not affected significantly by pressure, but elevated pressures can accelerate some undesirable olefin reactions, such as polymerization. Hence low reaction pressure is generally favored.
  • Partial pressure of the hydrocarbon during the isomerization generally will be in the range of about atmospheric to about 200 psig (i.e. about 1.03 X 10 5 Pa to about 148 x 10 6 Pa). More preferably the reaction pressure for isomerization does not exceed 100 psig (7.9 x 10 5 Pa).
  • the contact time for the hydrocarbon in such isomerization reactions expressed in volumes of liquid feed stock per volume of catalyst per hour (LHSV) , is in the range of about 0.1 to about 15, preferably about 0.5 to about 5.
  • a mixed C 4 cut from a FCCU is fed via flow line 1 and an effectuating amount of hydrogen is fed via flow line 2 both being combined in flow line 3 and fed to first distillation column reactor 10 containing a bed 12 of hydroisomerization catalyst in the form of a catalytic distillation structure.
  • first distillation column reactor 10 the butadienes are hydrogenated to butenes.
  • the hydrotreating is operated to isomerize a portion of the butene-1 to higher boiling butene-2.
  • the butene-2 in the feed along with that formed from the isomerization is taken as bottoms via flow line 4 and fed via line 4a to skeletal isomerization reactor 20 containing a fixed bed 22 of skeletal isomerization catalyst wherein a portion of the butene-2 is skeletally isomerized to isobutylene.
  • the butene-2 can be recovered via line 4b.
  • the skeletal isomerization products are removed via flow line 5.
  • the overheads from the first distillation column hydrotreating reactor 10 containing the isobutylene and inerts including butanes and butene-1, are taken via flow line 6 and combined with skeletal reactor products from flow line 5a into flow line 7.
  • Methanol is added via flow line 13 and the combined stream fed down flow to guard bed reactor 30 containing a fixed bed 32 of etherification catalyst wherein a considerable amount (80-90%) of the isobutylene reacts with methanol to form MTBE.
  • the effluent from the guard bed reactor 30 is fed via flow line 8 to a second distillation column reactor 40 containing a bed 42 of etherification catalyst in the form of a catalytic distillation structure wherein the remainder of the isobutylene is reacted with methanol to form MTBE which, being higher boiling, is taken as bottoms via flow line 11.
  • the overheads being essentially depleted of isobutylene and containing butene-1, butanes and unreacted methanol, is taken via flow line 9.
  • the methanol is recovered and recycled (not shown) and the stream, now having little butadiene, is suitable for feed to a cold acid alkylation process.
  • An alternative to combining the skeletal isomerization reactor effluent with the overheads from the first distillation column reactor is also shown as dotted flow line 5b.
  • the effluent from the skeletal isomerization reactor 20 may be recycled back to the first distillation column reactor 10 via flow line 5b where the isobutylene is taken along with the overheads for feeding to the etherification reactor.
  • the unconverted butene-2 in the effluent from the skeletal isomerization reactor is taken as bottoms and recycled to the skeletal isomerization reactor.
  • a slip stream (not shown) would be required to prevent build up of butene-2 in the system.
  • there is a reflux for each distillation column reactor but those along with other standard equipment such as reboilers and condensers are not shown, their design and operation being in the knowledge of one of ordinary skill in the art of distillation column design and operation.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

L'invention concerne un procédé dans lequel on hydromérise un courant d'isobutylène dilué contenant des butènes normaux pour enlever le butadiène et pour isomériser le butène-1 en butène-2 et séparer simultanément le butène-2 à point d'ébullition supérieur du reste du courant de C4 dans un réacteur à colonne de distillation. Les distillats de tête contenant une charge d'alimentation d'isobutène concentré provenant du réacteur à colonne de distillation sont envoyés conjointement avec du méthanol à un réacteur d'éthérification dans lequel l'isobutylène réagit avec le méthanol pour former de l'éther méthyltertiobutylique. On peut isomériser par le squelette les fonds de butène-2 pour les transformer en isobutène et les utiliser dans un réacteur d'éthérification.
PCT/US1997/007171 1996-08-15 1997-04-28 Procede de production d'ether methyltertiobutylique WO1998006687A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU28181/97A AU2818197A (en) 1996-08-15 1997-04-28 Process for the production of mtbe

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US2401896P 1996-08-15 1996-08-15
US60/024,018 1996-08-15

Publications (1)

Publication Number Publication Date
WO1998006687A1 true WO1998006687A1 (fr) 1998-02-19

Family

ID=21818428

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1997/007171 WO1998006687A1 (fr) 1996-08-15 1997-04-28 Procede de production d'ether methyltertiobutylique

Country Status (2)

Country Link
AU (1) AU2818197A (fr)
WO (1) WO1998006687A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5087780A (en) * 1988-10-31 1992-02-11 Chemical Research & Licensing Company Hydroisomerization process
EP0605822A1 (fr) * 1993-01-06 1994-07-13 Stone & Webster Engineering Corporation Procédé intégré pour la production d'éther méthyl tertio-butyl (MTBE)
WO1995015934A1 (fr) * 1993-12-08 1995-06-15 Chemical Research & Licensing Company Hydrogenation selective de composes hautement insatures dans un courant d'hydrocarbures

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5087780A (en) * 1988-10-31 1992-02-11 Chemical Research & Licensing Company Hydroisomerization process
EP0605822A1 (fr) * 1993-01-06 1994-07-13 Stone & Webster Engineering Corporation Procédé intégré pour la production d'éther méthyl tertio-butyl (MTBE)
WO1995015934A1 (fr) * 1993-12-08 1995-06-15 Chemical Research & Licensing Company Hydrogenation selective de composes hautement insatures dans un courant d'hydrocarbures

Also Published As

Publication number Publication date
AU2818197A (en) 1998-03-06

Similar Documents

Publication Publication Date Title
EP0643033B1 (fr) Réacteur de distillation catalytique à usage multiple et un procédé d'étherification utilisant celui-ci
US6169218B1 (en) Selective hydrogenation of highly unsaturated compounds in hydrocarbon streams
EP0733030B1 (fr) Hydrogenation selective de composes hautement insatures dans un courant d'hydrocarbures
EP0751106B1 (fr) Procédé intégré pour la production du butène-1
CA2264137C (fr) Procede d'hydrogenation selective simultanee d'acetylenes et de 1,2-butadiene dans des courants d'hydrocarbures
US6420619B1 (en) Cracked gas processing and conversion for propylene production
CA2885002C (fr) Production de propylene par metathese avec peu ou sans ethylene
AU710971B2 (en) Etherification-hydrogenation process
ZA200406618B (en) Process for producing propylene and hexene from C4olefin streams
US4754078A (en) Integrated etherification process with isomerization pretreatment
US5698760A (en) Olefin metathesis
US6005150A (en) Process for the production of butene-1 from a mixture of C4 olefins
US6156947A (en) Process for the production of butene-1 from a mixture of C4 olefins
US20210395178A1 (en) Selective dimerization and etherification of isobutylene via catalytic distillation
US5210327A (en) Etherification with skeletal olefin isomerization
US6495732B1 (en) Olefin isomerization process
US4731490A (en) Process for methyl, tertiary butyl ether production
WO1997032838A1 (fr) Obtention d'un produit de butene-1 de qualite superieure a partir d'un flux de c4 riche en butadiene
US5792891A (en) Integrated process for the production of tame
US11312671B2 (en) Process for the controlled oligomerization of butenes
US5113023A (en) Removal of linear internal olefins from steam active dehydrogenation recycle stream
WO1998006687A1 (fr) Procede de production d'ether methyltertiobutylique
US20230027740A1 (en) Trifunctional processes in catalytic distillation

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AL AM AT AU AZ BB BG BR BY CA CH CN CZ DE DK EE ES FI GB GE HU IL IS JP KE KG KP KR KZ LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK TJ TM TR TT UA UG US UZ VN AM AZ BY KG KZ MD RU TJ TM

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH KE LS MW SD SZ UG AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: CA

NENP Non-entry into the national phase

Ref country code: JP

Ref document number: 1998509676

Format of ref document f/p: F

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase