JPH03505338A - Etherification of olefins with paraffin dehydrogenation and conversion to liquid fuels - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Etherification of olefins with paraffin dehydrogenation and conversion to liquid fuels The present invention relates to a method for converting olefinic hydrocarbons into liquid fuels. olefins by conversion of olefins to gasoline and dehydrogenation of paraffins. The present invention relates to a system for producing methyl tertiary alkyl ether as well as production of methyl tertiary alkyl ether.

The mainstream of research in recent years for producing high-octane gasoline has been to improve the octane value of raw materials. for blending with lower aliphatic alkyl ethers as agents and auxiliary fuels. Ru. C1-cr methyl alkyl ethers, especially methyl tertiary butyl ether (M TBE) and tertiary amyl methyl ether (TAME) are It turned out that there was a significant increase in the price of the product.

Reacting imbutylene with methanol in the presence of an acidic catalyst to provide MTBE TAM can be obtained by reacting imbutylene with methanol in the presence of an acidic catalyst. It is known that E can be produced. In these etherification methods An important interlayer is that not all of the methanol is converted. etherification Separation of methanol from the reaction products requires that methanol coexist with hydrocarbons in a very dilute manner. The tendency to form boiling mixtures and the measurability of both water and hydrocarbons This is made difficult by the high solubility of tanol.

Is it advantageous from an equilibrium point of view to use a large excess of methanol in etherification? Possibly, but the separation problem mentioned above prevents it from doing so. These factors The main reason for this is the separation and recycling of common methanol in etherification reactions. The costs associated with circulation represent approximately 30% of the cost of the entire etherification process.

U.S. Pat. No. 4,684.757 discloses that a zeolite-type catalyst converts methanol into an olefin. etherification reaction to zeolite catalytic conversion to olefins. directing unreacted methanol from the reaction, thereby separating and recycling the methanol. It discloses that it can be utilized by removing the need for it. U.S. Patent No. 3. No. 9130.978 and No. 4.021. ．． No. 502 is C2-C, olefin Alone or mixed with paraffinic components to produce crystalline zeola with controlled acidity. discloses the conversion to higher hydrocarbons using carbonate. Anti-mild severity The reaction conditions are mainly olefins in the gasoline boiling range with little paraffin conversion. It is advantageous for conversion to chloride products.

Mild reaction temperatures and high operating pressures allow for distillate range fuels and lower olefins. can produce fins. U.S. Patent No. 4.150゜062, U.S. Patent No. 4,21 1,640, 4.227.992, 3.931.349, and No. 4,404.414, and Chang, C.D., Catalysis. Review Scientific Engineering (Catal, Rev, -5ci, Eng, ), 25.1 (1983) Processing techniques in this field in which fins can be used as raw materials are described.

The object of the present invention is to obtain methyl tertiary alkyl ether from in-alkene-rich hydrocarbons. and to provide an improved method of producing high octane gasoline. Ru.

Lower alcohols such as methanol can be used in large stoichiometric excess It has been found that high octane gasoline can be produced using an improved etherification process. It was taken out. Optionally, C1-hydrocarbons may be separated from the dehydrogenation process to produce zeolite. to an olefin conversion zone containing a metallosilicate catalyst such as SM-5. I can do it.

According to the invention, a method for preparing ether-rich fuels and olefinic gasolines converts raw materials containing C4+ alkenes and excess lower alcohols into acidic ethers. reacting in the presence of a catalyst to obtain a product stream comprising a C-tertiary alkyl ether; The product stream is separated to remove ether-rich gasoline range hydrocarbons, unreacted alcohol and C4- or C6-hydrocarbons are obtained, unreacted alcohol and C4-/Cs - hydrocarbons at elevated temperature in the presence of a catalyst comprising an intermediate pore zeolite, from C1 to C , paraffin, C1- with a mixture consisting of hydrocarbons and light gases.

The paraffins are converted into a liquid product containing decaolefinic gasoline, and the paraffins are subjected to dehydrogenation conditions. Under conditions, the C4-C, olefins are reconverted and the olefins are recycled to form the C1+ isocarbons. Including feeding with alkenes.

The preferred lower alcohol is methanol and the preferred ether is C3+ methyl Contains tertiary alkyl ether. The raw material is brought into contact with the neetilization catalyst in the liquid phase. may further consist of C4-C1 hydrocarbons, C4-C, alkenes and and C6+ gasoline range including non-etherifiable aliphatic hydrocarbons. Next to etherification The separation can be carried out by distillation.

The mixture obtained by contacting with the zeolite catalyst is brought into contact with the zeolite catalyst. It has a higher average molecular weight than the raw material and advantageously contains branched C6-C hydrocarbons. That C 1-Recycle the hydrocarbons to remove unreacted alcohol and C4-/C6-hydrocarbons. Can be supplied together.

Returning to the etherification step, the obtained unreacted alcohol and c,-/CS-charcoal Hydrogen oxides can form azeotropes. Lower alcohols can be used as catalysts for etherification. A stoichiometric excess of 2 to 50% relative to the C6+ isoalkene is present in the raw material to be brought into contact with the medium. Suitably present in excess, preferably 3 to 33%, more preferably 3 to 1% Present in 0% excess. The components of this raw material are butylene isomers and light olefins. It may consist of a mixture of naphtha and methanol. ether rich mixture It is advantageous to consist of The raw material brought into contact with the zeolite catalyst is unreacted methane. It can consist of a mixture of paraffin, paraffin and butylene.

In a particularly preferred flowsheet, the product stream from the etherification is The methanol is separated by aqueous extraction and distillation, from which unreacted methanol is removed. The overhead vapor stream containing a portion of the zeolite catalyst and ca-/cs-hydrocarbons is The bottom liquid stream from the distillation contains ether-rich gasoline and the remaining Unreacted methanol forms part of the aqueous stream from which it is recovered and recycled to produce ether. is supplied to the catalyst.

A suitable etherification catalyst is a sulfonic acid resin, in which case the reaction is carried out at 40 to 80°C. A response will be taken. The zeolite preferably has a constraint index of 1 to 12, and has a silicon ZSM- in which the carbon/alumina molar ratio is 25 to 80 and at least a portion is in the hydrogen type. 5 is preferred, in which case the conversion is carried out at a temperature of 204-500°C and 420-21°C. It is advantageously carried out under a pressure of 00 kPa.

The dehydrogenation reaction can be carried out using a catalyst, in which case a catalyst containing a group III metal is used. Preferably used, the dehydrogenation conditions are a temperature of 550-650°C and a temperature of 16.95-650°C. Contains a pressure of IO1,7kPa.

In another aspect, the present invention provides the use of C10 hydrocarbons as ether-rich liquid fuels and high grade This is a method for converting (a) C, + isoalkenes into aliphatic/aromatic gasolines. The fresh hydrocarbon stream containing The methyl tertiary alkyl obtain an effluent stream containing ether; (b) separating the etherification effluent stream to contain ether-rich gasoline range hydrocarbons; A first stream and a second stream containing unreacted methanol and C4- or C,-hydrocarbons. (c) subjecting the second stream to olefin oligomerization conditions in the conversion zone; (d) contacting the conversion zone olefin oligomer with an acidic metallosilicate catalyst at an elevated temperature; The gomerized effluent stream is separated to produce C6-C, hydrocarbons, C1 hydrocarbons and light gases. A component stream consisting of C and C6+ olefinic gasoline is obtained, (e) c, ~CS A hydrocarbon stream is contacted with a dehydrogenation catalyst under dehydrogenation conditions to remove C6-C paraffins. Separate the dehydrogenated effluent stream (converted to olefins, Cf’) containing C60 and fins. A portion of it is sent to the etherification zone along with the fresh hydrocarbon stream and methanol to tertiary arylalkyl ether.

FIG. 1 is a schematic diagram of a process 70 of one embodiment of the present invention. In a new embodiment, the main components of known methods can be integrated to provide great advantages in purification technology. Producing high octane gasoline and distillates to provide benefits and amazing advances. Build. Known methods can be used to improve component processing performance and achieve surprising benefits of combined methods. combinations in unique ways that provide Combined method is etherification production of ethers such as MTBE and TAME, ethers such as methanol Conversion of alcohol to gasoline (known as MTG process) and olefins (known as the MOG process). MTO and MO The G method is a closely related method that uses intermediate pore (5-7μ+m) zeolites as catalysts. The conversion reaction is used for the production of olefins and for the production of olefins. Selected to promote conversion to gasoline. In addition to the above method, a dehydrogenation step is added. Combining with the novel method results in a fully integrated method of the invention .

Resin under mild conditions with methanol and imbutylene and imbutylene Catalytic reactions are a well-established technology, and were developed by Reynolds (R,W, Reyno lds), The Oil and Gas Journal Gas Journal), July 16, 1975 1 Pecci (S, Pecci ) and Floris (T, Floris), /X hydrocarbon processing (Hydrocarbon Processing), December 1977, and Chase (J, D., Chase) et al., The Oil and Gas Journal, April 9, 1979, pages 149-152. preferred The catalyst is a bifunctional ion exchange resin that etherifies and isomerizes the reactant stream. . A typical acid catalyst is Amberlyst 15 sulfonic acid It is resin.

C4-C physoolefins to MTBE and other methyl tertiary alkyl ethers U.S. Pat. No. 4.544.766 and U.S. Pat. No. 4.6 No. 03.225. Ether and hydrocarbons from etherification effluent Suitable extraction and distillation techniques for recovering raw streams are also well known to those skilled in the art.

As mentioned above, low The class paraffins are separated and sent to a dehydrogenation zone where they are dehydrogenated to obtain olefins. P Paraffinic monools like propylene and butylene like lopane and butane. Conversion to olefins can be achieved by thermal or catalytic dehydrogenation. thermal A general description of dehydrogenation (i.e. steam cranking) is found in the Encyclopedia Encyclopedia of Chemical Technology micalT echnolog)’), Kirk and Osmer (Ed.), Volume 19, 1982, 3rd edition, pp. 232-235. It is. Various catalytic dehydrogenation methods are available at Air Press, Allentown, Pennsylvania. Air Products and Che micals.

Houdry Catofin Process (Houdry Catofi, Inc.) nProcess), located in Des Moines, Illinois. UOP Inc.'s Oleflex Process (○1eflex) Process), and the method described in U.S. Pat. No. 4,191,846. known from the prior art including. “Dehydrogenation Links L Peasy Too More Octane (Dehydrogenation L1 nksL　P　G　G　0ctane)」、G usso w) et al., Oil and Gas Journal rnal), Foodry Cadfin, described on December 8, 1980. The process involves a fixed bed multistage catalytic method for the conversion of paraffins to olefins. nothing.

Typically, this method uses 5 to 30 inches of mercury absolute pressure (16,95 to IO 1,7 kPa) and operated at 550-650 °C with hot reactor effluent at high temperature. be done. Since dehydrogenation is an endothermic reaction, the feed stream is usually A furnace is required to provide heat. 'Cz/Cs dehydrogenation ・Updated (Dehydrogenation Updated) , Verrow et al., Hydrocarbon Processing (Hydr) ocarbon Processing), April 1982. The UOP Oleflex process uses a continuous catalytic reactor. US Patent No. 4 ．． 191.846 to promote the catalytic dehydrogenation of paraffins to olefins. discloses the use of a Group I metal-containing catalyst.

In FIG. 1, the etherified hydrocarbon stream 20 is preferably an alkene-rich C 4+ hydrocarbon stream. The hydrocarbon stream is sent to etherification reactor 21 where the carbon mixed with methanol in excess of at least 2% relative to the alkene content of the hydrohydric stream; It will be done. A unique advantage of the present invention is the large stoichiometric excess of media in the etherification reaction. Tanol can be used, which promotes improved ether formation That's true. An excess of methanol of 2 to 50% can be advantageously used. A The tellurization reaction is carried out at 40-80°C, preferably about 60°C. etherification spill The liquid is passed through 23 to a fractionator 24, which produces a bottom stream 2 consisting of ether-rich gasoline. 5 are separated. The overhead fraction from the fractionator consists essentially of etherified excess methanol. and all or most of the unreacted hydrocarbons. The mixture is olefin to gaso to phosphorus (MOG) conversion unit 27, where C8-olefins are optionally added. A feed stream 28 consisting of hydrocarbons is supplemented. Olefin is 420kPa-2 gas at a pressure of 100 kPa (60-300 psi) and a temperature of 204-500°C. Converted to Sorin. Under these conditions, methanol in the mixture also C, is converted to higher hydrocarbons including olefins. The conversion effluent is passed through 29. is sent to the fractionator 30, and C3-fuel gas 311c, ~Cl paraffin 32 and and C, -C.

The gasoline product 33 is separated. C6~C, paraffins are sent to the dehydrogenation area 34. and dehydrogenated to form olefins. C,~cs olefin dehydrogenated effluent stream 35 and sent to the etherification area 21. C1-olefin if necessary A stream can also be recovered from the dehydrogenation stream and recycled to olefins to reactor 27. . In addition, the C8 to C3 components exiting the reactor 27 are sent to a dehydrogenation device, and inside the reactor 27, It can be further converted into olefins which can be modified. The dehydrogenation reactor effluent is , without or insufficiently separating the C3-component from the C-component. It can be supplied at any time. This allows the MOG separation part to be It can be used as the only gas plant.

According to an advantageous embodiment of the invention, the etherification reaction effluent stream contains excess or unreacted material. Unreacted methanol extracted with water to remove tanol and recovered by distillation Typical etherification for MTBE production where the water is recycled to the etherification reactor The method has been improved so that the hydrocarbon portion of the effluent stream after aqueous extraction contains unreacted methanol. is separated into a C40 hydrocarbon overhead stream, which is separated by contact with an intermediate pore shape-selective catalyst. is further converted and then the 04-C6 aliphatic hydrocarbons are dehydrogenated as described above. It will be done.

The catalyst used in the conversion of methanol and olefins according to the present invention is Pore zeolites, the most prominent one being zeolite ZSM-5. typical Zeolites with a restraint index of 1 to 12 usually contain Al1 in the zeolite skeleton. , Ga, B or I; can be modified by incorporating tetrahedral coordination metals such as Fe. synthesized using a Stead active site. The advantage of ZSM-5 structure is that it can withstand various acidity one or more crystalline metallosoricates having a tetrahedral volume or Using high silicon materials such as those described in Canadian Patent No. 1.121,975 It can be used by Zeolite ZSM-5 is U.S. Patent No. 3.7 It can be determined by the X-ray diffraction data described in No. 02,866.

Other suitable zeolites are ZSM-11, ZSM-12, ZSM-22, ZSM -23, ZSM-34, ZSM-35, ZSM-388 and ZSM-48. , U.S. Pat. No. 3,709.979, U.S. Pat. No. 3.832,449, and U.S. Pat. No. 4.076.979, No. 4.076.842, No. 4. O16,245 , No. 4.086,186, No. 4.046,859 and No. 4.375 ．． It is determined from the X-ray data described in No. 573. Silica/alumina molar ratio Aluminosilicate type ZSM-5 having a value of 15 to 1600 can be used, A preferred catalyst is hydrogen type zeolite ZSM with a silica/alumina molar ratio of 25 to 80. -5. Zeolites are usually made of alumina, silica and/or clay. Zeolite is used in a composite state with a heat-resistant oxide matrix such as 5 to 95% by weight, preferably 50 to 75% by weight.

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Claims (22)

[Claims] 1. Raw materials containing C6+ isoalkenes and excess lower alcohols are converted into acidic ethers. reaction in the presence of a catalyst to obtain a product stream containing C5+ tertiary alkyl ethers. , the product stream is separated into ether-rich gasoline-range hydrocarbons and unreacted alcohols. and C6- or C5-hydrocarbons, resulting in unreacted alcohol and C4-/C5 - contacting hydrocarbons at high temperatures with a catalyst comprising intermediate pore zeolites to produce C4-C5 A mixture of paraffins, C3-hydrocarbons and light gases and C6+ olefins The paraffins are converted into a liquid product consisting of C4-based gasoline under dehydrogenation conditions. Convert to C5 olefin and recycle the olefin to combine with the C4+ isoalkene. an ether-rich liquid fuel and an olefinic gasoline; method of manufacturing. 2. The lower alcohol is methanol, and the ether is C5+ methyl tertiary alkyl. 2. The method of claim 1, further comprising a ether. 3. The method according to claim 1 or 2, wherein the raw material is brought into contact with the etherification catalyst in a liquid phase. . 4. The raw material comprises a C4-C9 hydrocarbon, a C4-C7 alkene and a C4-C9 hydrocarbon. 5+Gasoline range Any one of claims 1 to 3 containing non-etherifiable aliphatic hydrocarbons. The method described in. 5. 5. A method according to any one of claims 1 to 4, wherein the separation is carried out by distillation. 6. The above mixture has a higher average molecular weight than the raw material brought into contact with the Celite catalyst. , a branched C4-C5 hydrocarbon. 7. The above C3-hydrocarbon is recycled to form the above unreacted alcohol and C4/C5 carbon. 7. The method according to claim 1, wherein the method is fed together with hydrogen hydride. 8. There is a possibility that the unreacted alcohol and C4-/C5-hydrocarbons form an azeotrope. 8. The method according to any one of claims 1 to 7. 9. The lower alcohol is present in the feedstock that is brought into contact with the etherification catalyst. Any one of claims 1 to 8, present in a stoichiometric excess of 2 to 50% relative to Ken. The method described in. 10. The method according to claim 9, wherein the excess amount is 3 to 33%, preferably 3 to 10%. Law. 11. The raw materials brought into contact with the etherification catalyst are butylene isomers, light olefin inner The method according to any one of claims 1 to 10, comprising a mixture of fusa and methanol. . 12. The raw material to be brought into contact with the zeolite catalyst contains unreacted methanol, paraffin and 12. A method according to any one of claims 1 to 11, comprising a mixture of and butylene. 13. The above ether-rich gasoline range hydrocarbons include MTBE, TAME and 13. A process according to any of claims 1 to 12, comprising a mixture of reacted naphthas. 14. The product stream from the etherification is processed by aqueous extraction of unreacted methanol and distillation. and the overhead vapor stream from the distillation is fed to a zeolite catalyst. The bottoms stream from the distillation contains ether and some unreacted methanol. The remaining unreacted methanol forms part of the aqueous stream and the aqueous 14. Any of claims 1 to 13, wherein the etherification catalyst is recovered from the stream and recycled and fed to the etherification catalyst. The method described in 15. Any one of claims 1 to 14, wherein the etherification catalyst is a sulfonic acid resin. the method of. 16. Claims 1 to 15 wherein the reaction using an etherification catalyst is carried out at a temperature of 40 to 80°C. The method described in any of the above. 17. 17. The zeolite has a constraint index of 1 to 12. the method of. 18. The zeolite is ZSM-5 with a silica/alumina molar ratio of 25 to 80. 18. A method according to any one of claims 1 to 17. 19. 19. A method according to any of claims 1 to 18, wherein the zeolite is in hydrogen form. 20. The conversion in the presence of a zeolite catalyst was carried out at a temperature of 204-500 °C and The method according to any one of claims 1 to 19, which is carried out under a pressure of 420 to 2100 kPa. . 21. Claims 1 to 20 wherein the dehydrogenation is carried out using a catalyst comprising a Group VIII metal. The method described in any of the above. 22. Dehydrogenation conditions are a temperature of 550-650°C and 16.95-101.7kP 22. A method according to any of claims 1 to 21, comprising a pressure of a.