KR101474889B1 - Process and apparatus for increasing weight of olefins - Google Patents

Abstract

Process and apparatus for converting FCC olefins to heavy compounds are provided. The heavy compounds are more easily separated from unreacted paraffins. The heavy compounds may be recycled to the FCC unit or may be transported to a separate FCC unit. Suitable conversion zones are oligomerization and aromatic alkylation zones.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a process for increasing the weight of olefins,

Claim of priority

This application claims priority from US Application No. 12 / 751,623, filed March 31, 2010, and US Application No. 12 / 751,658.

Technical field

The present invention relates to a process and apparatus for converting olefins mixed with paraffins into compounds of higher molecular weight that are readily separated from unconverted paraffins.

Fluid catalytic cracking (FCC) is a catalytic hydrocarbon conversion process that is achieved by contacting heavier hydrocarbons with the catalyst particulate material in the fluidization reaction zone. Unlike hydrocracking, the catalytic cracking reaction is carried out in the absence of significant amounts of hydrogen or without the consumption of hydrogen. As the cracking reaction progresses, a significant amount of highly carbonaceous material (called coke) is deposited on the catalyst to produce a spent catalyst that has been coked or spent. The lighter product on the vapor phase is separated from the spent catalyst in the reactor vessel. The spent catalyst is stripped under an inert gas, such as steam, so that the trapped hydrocarbon gas can be stripped from the spent catalyst. High temperature regeneration with oxygen in the regeneration zone burns the coke from the (pre-stripped) spent catalyst. From this process various products (including gasoline products and / or light products such as propylene and / or ethylene) can be obtained.

In such a process, a single reactor or a dual reactor can be used. One reactor can be operated in customized conditions to maximize products such as light olefins (including propylene and / or ethylene), although additional capital costs can arise by using dual reactor devices.

It may be efficient to maximize the yield of the product in one reactor. Additionally, there may be a desire to maximize the production of the product from the reactor as long as it can be recycled to another reactor to produce the desired product such as propylene.

Decomposition of C ₄ -C ₇ olefins yields high yields of propylene. Recycling the C ₄ -C ₇ -rich stream to the FCC reactor can be used to further increase the production of propylene. However, such recycling induces the concentration of refractory paraffins in the recycle stream and requires effective purification or high recycle flow rates. There is no simple way to separate olefins from paraffins in streams having a wide range of boiling points.

It is a known technique to oligomerize an olefin to a heavy olefin on a heterogeneous catalyst to produce an automotive fuel. In addition, techniques for alkylating olefins with paraffins over homogeneous acid catalysts to make automotive fuels are also known. Alkylation of olefins with benzene and other aromatic components, typically on heterogeneous catalysts, is also known for making petrochemical feedstocks containing detergent precursors.

It is necessary to easily separate the olefin from the paraffin in the product stream.

SUMMARY OF THE INVENTION

In one exemplary embodiment, the present invention involves a process for converting an olefin to a heavy compound. C ₄ olefins and paraffins and C ₅ - C ₇ is passed through the olefins and paraffins in a conversion zone aromatic and C ₅ - by alkylation of C ₇ olefins, C ₅ - C ₇ olefins to a molecular weight of greater C ₅ - C ₇ To convert the C ₄ olefin to a C ₄ -derived compound having a larger molecular weight. C ₄ derived compounds are separated from C ₄ olefins and paraffins and C ₅ -C ₇ derived compounds are separated from C ₅ -C ₇ olefins and paraffins. Finally, the C ₄ -derived compound and the C ₅ -C ₇ -derived compound are fed to the FCC reactor.

In a further exemplary embodiment, the invention involves a process for converting an olefin to a heavy compound. The first stream of C ₅ - C ₇ olefins and paraffins is passed to the first zone to convert the C ₅ - C ₇ olefins to a C ₅ - C ₇ derived compound of higher molecular weight. A second stream of C ₄ olefin and paraffin is passed through the second zone to convert the C ₄ olefin to a C ₄ derived compound of higher molecular weight. C ₄ derived compounds are separated from C ₄ olefins and paraffins, and C ₅ -C ₇ derived compounds are separated from C ₅ -C ₇ olefins and paraffins. Finally, the C ₄ -derived compound and the C ₅ -C ₇ -derived compound are fed to the FCC reactor.

In a further exemplary embodiment, the invention involves a process for converting an olefin to a heavy compound.

The cracking catalyst is contacted with a hydrocarbon stream to decompose the hydrocarbon into cracked product hydrocarbons having a low molecular weight and to accumulate coke on the cracking catalyst to provide a cracked cracking catalyst. The cracked cracking catalyst is separated from the cracked product. The coke on the cracked cracking catalyst is burned with oxygen to regenerate the cracking catalyst. The decomposed product is separated in the main fractionation column. At least a portion of the overhead stream from the main fractionation column is compressed to provide a compressed overhead stream. The liquid stream is separated from the compressed overhead stream and at least some of the liquid stream is deprotonated to provide a C ₄ -C ₇ stream of paraffins and olefins. The stream of C ₄ - C ₇ olefins and paraffins is fed to the conversion zone to convert the C ₄ - C ₇ olefins into C ₄ - C ₇ - derived compounds of higher molecular weight.

In one embodiment, the present invention includes an apparatus for converting an olefin to a higher molecular weight compound to produce an FCC feed. The apparatus includes a process fractionation column for separating an overhead stream comprising a C ₃ -rich overhead stream from a C ₅ -rich bottoms stream. The aromatic alkylation reactor is in communication with the bottom line of the process fractionation column for the alkylation of olefins and aromatics in the C ₅ -rich bottoms stream. The product column is in communication with the aromatic alkylation reactor to separate the alkylaromatics from unreacted compounds from the C ₅ -rich bottoms stream. Finally, the FCC reactor communicates with the bottom line of the product column.

In a further embodiment, the invention includes an apparatus for converting an olefin to a heavy compound to produce an FCC feed. The apparatus includes a process fractionation column for separating an overhead stream comprising a C ₃ -rich overhead stream from a C ₅ -rich bottoms stream. The first conversion zone communicates with the bottom line of the process fractionation column to convert the C ₅ - C ₇ olefin into a C ₅ - C ₇ --derivative compound of higher molecular weight. The second conversion zone communicates with the overhead line of the process fractionation column to convert the C ₄ olefin to a C ₄ -derived compound of higher molecular weight. The product splitter column communicates with the first conversion zone to separate the C ₅ -C ₇ derived compound from the unreacted compound. Finally, the FCC reactor communicates with the bottom line of the product splitter column.

In a further embodiment, the invention includes an apparatus for converting an FCC olefin to a heavy compound. The apparatus includes a fluidized catalytic cracking reactor comprising a cracked cracking catalyst in contact with a hydrocarbon stream to decompose the hydrocarbon into cracked product hydrocarbons having a low molecular weight and to accumulate coke on the cracking catalyst. The catalyst regenerator burns the coke on the cracked cracking catalyst with oxygen to regenerate the cracking catalyst. The main fractionation column is in communication with the flow catalytic cracking reactor to separate the cracked product. The compressor communicates with the overhead line of the main fractionation column to compress at least a portion of the overhead stream from the main fractionation column. The receiver communicates with the compressor to separate the liquid stream from the compressed overhead stream. The process fractionation column communicates with the receiver to deprotonate at least a portion of the liquid stream. The conversion zone is in communication with the process fractionation column to convert the C ₄ - C ₇ olefin to a C ₄ - C ₇ --derivative compound of higher molecular weight.

Additional features and advantages of the present invention will appear in the detailed description, drawings, and claims of the present invention.

Figure 1 is a schematic illustration of an FCC unit and an FCC product recovery area.
Figure 2 is a schematic illustration of an alternative FCC unit and an FCC product recovery area.
3 is a schematic illustration of a further alternative FCC unit and FCC product recovery area.
Figure 4 is a schematic diagram of an oligomerization conversion zone.
Figure 5 is an alternative schematic diagram of an aromatic alkylation conversion zone.

Justice

The term "communication" means that the material flow between the listed components is performed operatively.

The term "downstream communication" means that at least a portion of the material flowing from a subject in the downstream stream can operatively flow to the object to which it communicates.

The term "upstream communication" means that at least a portion of the material flowing from the subject in the upstream stream may be operatively flowing to the communicating object.

The term "column" means a distillation column or columns for separating one or more different volatiles that may have a reboiler on the bottom and a condenser on top. Each column includes a condenser disposed at the top of the column for condensing a portion of the overhead stream and refluxing it to the top of the column and a condenser located at the bottom of the column for evaporating a portion of the bottom stream and returning to the bottom of the column. And a reboiler disposed in the reboiler. The feed to the column may be preheated. The top pressure is the overhead vapor pressure at the outlet of the column. The bottom temperature is the temperature of the liquid bottom outlet. The top line and the bottom line refer to the net line from the bottom stream column to the column of reflux or reheat.

As used herein, "component rich stream" means that the stream exiting the separation vessel has a greater concentration of its constituents than the feed being fed to the separation vessel.

As used herein, "component-lean stream" means that the stream exiting the separation vessel has a lower concentration of its constituents than the feed being fed to the separation vessel.

DETAILED DESCRIPTION OF THE INVENTION

The present inventors have devised a simple process for separating olefins from paraffins from the FCC product stream comprising C ₄ and heavy products, preferably C ₄ -C ₇ products, and recycling the olefins to the main FCC reactor or separate FCC reactor. The FCC product recovery zone may have one main fractionation column and one gas plant. The present invention includes reaction zones in which olefins are converted to different chemical species that can be readily separated from inert paraffins. The products derived from the converted and separated olefins can be recycled back to the main FCC reactor or the separate FCC reactor.

Referring to FIG. 1, where like reference numerals refer to like elements, FIG. 1 illustrates a refining composite 6 generally comprising an FCC unit zone 10 and a product recovery zone 90. The FCC unit zone 10 includes a reactor 12 and a catalyst regenerator 14. Modifications of the process typically include a cracking reaction temperature of 400 ° C to 600 ° C and a catalyst regeneration temperature of 500 ° C to 900 ° C. Both cutting and regeneration occurs at absolute pressures of less than 506 kPa (72.5 psia).

Figure 1 shows a typical FCC reactor 12 in contact with a regenerated cracking catalyst that enters the regenerated catalyst stand pipe 18 from a stream of crude oil or a stream of heavy hydrocarbon feed from a distributor 16. The contact may take place in a narrow riser 20 extending upwardly from the bottom of the reaction vessel 22. Contact between the feed and the catalyst is fluidized by gas from the fluidization line (24). In one embodiment, the heat from the catalyst evaporates the hydrocarbon feed or oil, and then the two are carried to the riser 20 through the reaction vessel 22, And decomposed into hydrocarbon products. An inevitable negative reaction occurs in the riser 20 to produce accumulated coke on the low catalytically active catalyst. The decomposed hard hydrocarbon product is then separated from the cracked cracking catalyst using a circulating separator comprising one or two circulators 28 and a first separator 26 in the reaction vessel 22. The gaseous cracked product is discharged to the line 32, which is conveyed from the reaction vessel 22 through the product outlet 31 to the downstream stream product recovery zone 90. The spent or coked catalysts need to be reproduced for further use. The cracked cracking catalyst, separated from the gaseous product hydrocarbons, enters the stripping zone 34, which is injected through a nozzle to purge the remaining hydrocarbon vapor. After the stripping process, the coked catalyst is transferred to the catalyst regenerator 14 through the spent catalyst catalyst stand pipe 36. An optional spent catalyst pipe 56 carries the spent catalyst from the stripping zone 34 at a rate controlled by the regulating valve to the riser reactor 12 through the spent catalyst inlet.

Figure 1 shows a catalyst regenerator 14 known as a combustor. However, other types of regenerators are also suitable. In the catalyst regenerator 14, a gaseous stream containing oxygen, such as air, is introduced through the air distributor 38 to contact the coked catalyst. The coke is burned from the coked catalyst to provide a regenerated catalyst and flue gas. To provide energy to the endothermic cracking reaction occurring in the riser reactor 20, the catalyst regeneration process applies a substantial amount of heat to the catalyst. Along the combustor riser 40 disposed in the catalyst regenerator 14, the catalyst and air flow upward together and are initially separated after being regenerated by being charged through the cancellation device 42. Additional recovery of the regenerated catalyst and flue gas from the withdrawal device 42 is accomplished by using first and second stage separator thyristors 44 and 46, respectively, disposed in the catalyst regenerator 14. Catalysts separated from the flue gas while the relatively light flue gases in the catalyst are discharged sequentially from the cyclones 44 and 46 are distributed through the deep legs at the cyclones 44 and 46 and the flue gases in the flue gas line 48 And is discharged from the regeneration vessel 14 through the flue gas outlet 47. The regenerated catalyst is transported to the riser 20 via the regenerated catalyst catalyst stand pipe 18. Depending on the result of the burning of the coke, the flue gas vapors exiting the catalyst regenerator 14 in line 48 contain CO, CO ₂ , N ₂ and H ₂ O together with minor amounts of other species. The hot flue gas exits the catalyst regenerator 14 through the flue gas outlet 47 in line 48 for further processing.

The FCC product recovery area 90 communicates downstream with the product outlet 31 via line 32. In the product recovery zone 90, the gaseous FCC product in line 32 is in direct communication with the lower zone of the FCC main fractionation column 92. Further, the main fractionation column 92 also communicates with the product outlet 31 in the downstream direction. A number of fractions of the FCC product are recovered from the heavy naphtha stream in line 96, light cycle oil (LCO) in line 95 taken from outlet 95a, heavy cycle oil Oil, HCO) stream, line 93, from the main column containing the heavy slurry oil. Any or all of the streams in lines 93-96 may be cooled to cool the main column, typically at a higher position, and pumped back to the main fractionation column 92. Gasoline and gaseous light hydrocarbons are removed from the main fractionation column 92 at the top of line 97 and condensed before entering main column receiver 99. The main column receiver 99 communicates downstream with the product outlet 31.

The aqueous stream is removed from the boot in the receiver 99. In addition, the condensed hard naphtha stream is also removed from the bottom of line 101 while the overhead stream is removed in line 102. A portion of the line 101 is again refluxed near the top of the main fractionation column 92 and the main fractionation column 92 communicates with the main column reactor 99 in the upstream stream. The overhead stream of line 102 contains gaseous light hydrocarbons that can contain a dilute ethylene stream. The streams of lines 101 and 102 enter the gas recovery zone 120 of the product recovery zone 90.

Although the gas recovery zone 120 is shown as being an absorption based system, any gas recovery system including a cooling box system may be used. To sufficiently separate the light gas components, the gaseous stream of line 102 is condensed in condenser 104. One or more compression stages may be used and the gaseous overhead stream of line 102 is pressurized to a pressure of 1.2 MPa to 3.4 MPa (gauge) (180-500 psig) to produce a condensed first FCC product stream Condensation, typically a two-stage condensation and an appropriate triple-stage condensation are used.

The condensed hard vapor phase hydrocarbon stream in line 106 may be combined with the stream in lines 107 and 108 and cooled and transferred to high pressure receiver 110. The aqueous stream from the receiver 110 proceeds to the main column receiver 99. In the high pressure receiver, the condensed vapor phase stream in the overhead line 112 is separated from the liquid stream at the bottom line 124. From the overhead of the high pressure receiver 110, the gaseous hydrocarbon stream of the line 112 proceeds to the low end of the first absorption column 114. In the first absorption column 114, the gaseous hydrocarbon stream is passed through the main column receiver 99 (the first column of the first absorption column 114) in the bottom of the line 101, through the C ₃ + hydrocarbon and the C ₂ -hydrocarbon Lt; / RTI > (resulting in separation). The separation is further improved by supplying stable gasoline from line 35 to the feed point of the bottom line 101. The first absorption column 114 communicates downstream with the overhead line 102 of the primary column receiver via the bottom line 101 and lines 106 and 112 of the primary column receiver 99. The liquid C ₃ + enriched bottoms stream in line 107 returns to line 106 prior to cooling. The first off-gas stream of line 116 from first absorption column 114 is in direct communication with the lower end of second absorption column 118. The second absorption column communicates downstream with the first absorption column (114). The LCO circulating stream in line 121, which is directed from line 95 to second absorption column 118, contains most of the C ₅ + material and some C ₃ -C ₄ Absorbs material. The second absorption column 118 communicates downstream with the main fractionation column 92 and the first absorption column 114. The C ₃ + enriched LCO from the second absorption column in the bottom bottom line 119 is returned to the main fractionation column 92 via a pump-around for line 95. The main fractionation column 92 communicates downstream with the second absorption column via the bottom line 119. The overhead of the second absorption column 118 comprising a dry gas consisting primarily of C ₂ -hydrocarbons with hydrogen sulphide, ammonia, carbon dioxide and hydrogen can be removed in the second off-gas stream of line 122, Can be further processed. The two absorption columns 114 and 118 do not have a condenser or reboiler, but a circulating return circuit can be applied.

The liquid from the high pressure receiver in line 124 is sent to the stripper column 126 for fractionation. The stripper column 126 communicates downstream with the receiver 110 via the bottom line 124. Most C ₂ - is removed within the overhead of the stripper column 126 and returned to the line 106 via the overhead line 108. In one aspect, the liquid bottom stream from the stripper column 126 is directed to the fractionation column 13 process via line 128. The stripper column 126 does not have a condenser, but receives the cooled liquid feed from line 124.

The process fractionation column 130 separates the C ₃ -rich overhead stream of line 132 from the C ₅ -, C ₆ - and / or C ₇ -rich bottoms stream of line 134. The overhead stream in the overhead line 132 from the process fractionation column 130 is the C ₃ Olefins and paraffins, preferably C ₃ and C ₄ Olefins and paraffins. The bottoms stream in the bottoms line 134 comprises C ₅ olefins and paraffins, preferably C _{5 ,} C ₆ and / or C ₇ (which are referred to herein as C ₅ -C ₇ olefins and paraffins) Olefins and paraffins. In addition, the bottoms stream in line 134 contains C ₅ + naphthene and C ₆ + aromatics as well as heavy naphtha components.

To further prepare light olefins, C ₄ -C ₇ olefins are sent to the FCC reactor 12 or to a separate FCC reactor (not shown). However, recycling the C ₄ -C ₇ stream of paraffins and olefins to the FCC reactor 12 results in the formation of inert paraffins. It is difficult to separate paraffins from olefins of all carbon numbers in the naphtha range. The present invention proposes a method for converting an olefin to a heavy compound so that the olefin can be easily separated from the unmodified hard paraffin.

As a specific example, a mixed stream of C ₃ and / or C ₄ olefins and paraffins in overhead line 132 may be sent to LPG splitter column 140. The LPG splitter column 140 communicates downstream with the overhead line 132 of the process fractionation column 130. A stream of C ₃ olefins and paraffins separated in overhead line 142 of LPG splitter column 140 may be subjected to further processing to recover propylene. The bottoms stream of C ₄ olefins and paraffins can be separated in the bottoms line 144.

A portion of the stabilized gasoline in the bottom line 134 can be recycled to the top of the first absorption column on the injection point of lines 101 and 112 to improve the recovery of C ₃ + have. In one embodiment, the net bottoms stream 136 from the debutanization column can be fractionated in the naphtha splitter column 150. The C ₆ +, C ₇ + or higher, preferably C ₈ + heavy naphtha streams may be recovered in the bottoms line 152 for further processing and / or storage. An overhead stream comprising C ₅ , C ₅ -C ₆ or higher, preferably C ₅ -C ₇ olefins and paraffins as well as naphthenes and aromatics is provided in line 154.

In one embodiment, C ₅ -C ₇ The overhead stream 154, which includes the olefin, That a bottom line 134 of the overhead line 154 and the process fractionation column 130 of the naphtha splitter column 150 and the downstream communication passage, C ₅ -C ₇ May be supplied to the first conversion zone 160, which may include a conversion zone. Any, some, or all of the C ₅ -C ₇ olefins may be converted to C ₅ -C ₇ -derived compounds having a higher molecular weight in the first conversion zone. Suitable reactions that may be performed within the first conversion zone 160 may include oligomerization or aromatic alkylation. The first product, which may comprise the C ₅ -C ₇ -derived product, is discharged from the first conversion zone in line 162.

The bottoms stream of the C ₄ olefins and paraffins in the bottoms line 144 is connected to the bottom line 144 of the LPG splitter column 140 and the overhead line 132 of the process fractionation column 130, (170). The second conversion zone may be a C ₄ conversion zone. C ₄ olefins can be converted into C ₄ -derived compounds having a higher molecular weight within the second conversion zone. Suitable reactions that may be performed within the second conversion zone 170 may include oligomerization or aromatic alkylation. The second product, which may comprise the C ₄ -derived product, is discharged from the first conversion zone in line 172. The same process or different process may be performed in each of the first and second switching zones 160, 170. In FIG. 1, the first conversion effluent in line 162 joins the second conversion effluent in line 172 and enters stabilization column 180. The two lines 162 and 172 may be separated or joined together to enter the stabilization column 180. Additionally, in the event that steam can enter the column 180 of liquid feed that may or may not be injected into line 162, the stream in line 172 may be cooled and separated. The stabilization column 180 may be in downstream communication with the first and second switching zones 160, 170.

The three streams can be separated and removed from the stabilization column 180. The overhead gas stream in line 182 containing the recoverable C ₃ -material enters the gas plant or is sent to the fuel gas. A side cut stream of C ₄ paraffin in line 184 may be recovered or may be subjected to further processing in an LPG processing zone or an oligomerization zone (described herein). The bottoms stream in line 186 containing heavy C ₄ and C ₅ -C ₇ derived compounds proceeds to product splitter column 190.

The product splitter column is in downstream communication with the first and second transition sections 160, 170, respectively, which are oligomerization or alkylation reactors, and the bottoms line 186 from the stabilization column 180. Alternatively, the line 162 may not enter the stabilization column 180, but bypasses the product splitter column 190 when the line 172 is separated into the stabilization column. The product splitter column can provide two streams. C ₅ -C ₇ in line 192 recovered for further processing The overhead stream comprising the unconverted material can be recovered for further use in a process such as a naphtha hydrotreater to remove sulfur for use in an alkylation process as described below or via a gasoline pool . Some or all of the bottoms stream in line 194 comprising C ₄ and C ₅ -C ₇ derived compounds having higher molecular weights such as alkylaromatics or oligomers may be recycled to the feed of the FCC reactor 12. The recycle stream in line 194 entering line 16 with the first feed is shown which may enter riser 20 at another location. According to one aspect, the FCC reactor 12 communicates downstream with the bottom line 194 of the product splitter 190. The bottoms fraction in line 194 can be returned to the FCC reactor 12 or to a different FCC reactor for further cracking to improve the yield of light olefins.

FIG. 2 shows an alternative embodiment to FIG. In Figure 2, only one switching zone 160 'is shown. The corresponding elements of Fig. 2 that are different from those of Fig. 1, however, are indicated by reference numerals with a prime sign ('). All other components of FIG. 2 are the same as in FIG.

In one aspect, the liquid bottoms stream in line 128 from the stripper column 126, which includes a portion of the liquid stream in the bottoms line 124, is directed to the process fractionation column 130 '. The process fractionation column 130 'communicates downstream with the stripping column 126 via a bottom line 128. Process fractionation column 130'includes a deprotonation column that separates the C ₃ -rich overhead stream in line 132 from the C ₄ -rich and / or C ₅ -rich bottoms stream in line 134 ' . The bottoms stream in line 134 'contains C _{4 ,} C _{5 ,} C ₆ (including olefins and paraffins, referred to herein as C ₄ -C ₇ streams) And / or C ₇ , while the overhead stream in line 132 'from the process fractionation column may comprise a C ₃ product comprising olefins and paraffins. In addition, the bottoms stream in line 134 'may contain C ₅ + naphthene and C ₆ + aromatics as well as heavy naphtha components.

A portion of the naphtha in the bottoms line 134 'may be recycled within line 135 to the top of the first absorption column above the injection point of lines 101 and 112 to improve the recovery of C ₃ +. In one embodiment, the net bottoms stream 136 from the deprotonation column may be fractionated in the naphtha splitter column 15. The C ₅ +, C ₆ +, C ₇ + or preferably C ₈ + heavy naphtha streams may be recovered via the bottom line 152 for further processing and / or storage. Naphthene and aromatics as well as an overhead stream comprising C ₄ , C ₄ -C ₅ , C ₄ -C ₆ or higher, preferably C ₄ -C ₇ olefins and paraffins, is provided by line 154 ' do.

In one embodiment, the overhead stream 154 'is communicated downstream with the bottom line 134' of the process fractionation column 130 'and has a first conversion zone 160, which may include a C _{4 to} C ₇ conversion zone '). Any, some or all of the C ₄ -C ₇ olefins may be converted to C ₄ -C ₇ -derived compounds of higher molecular weight in the first conversion zone. Suitable reactions that may be performed in the first conversion zone 160 'may include oligomerization or aromatic alkylation. The first product, which may include the C ₄ -C ₇ -derived product, is released from the first conversion zone in line 162 'and enters stabilization column 180. And proceeds to a C ₄ -C ₇ -derived product in an FCC reactor, as in FIG.

Figure 3 shows an alternative embodiment of Figures 1 and 2. In Figure 3, only one switching zone 160 " is shown. The elements shown in FIG. 3 that are different from those of FIG. 1, but which correspond to, are indicated by reference numerals with a prime sign (''). All other components of Fig. 3 are the same as in Fig.

The bottoms stream of the C ₄ olefin and paraffin in the bottoms line 144 "is connected to the bottom line 144" of the LPG splitter column 140 ", the overhead line 132 of the process fractionation column 130, Is conveyed to a first switching zone 160 " that communicates downstream with a bottom line 134 of the column 130 and an overhead line 154 " of the naphtha splitter column 150. The bottom line 144 " may join the overhead line 154 " or may enter the first switching zone 160 " separately.

A first switching section (160 '') has a first switch that has any, some or all of the C ₄ -C ₇ olefin having a molecular weight in the zone can be converted to the more C ₄ -C ₇ derived from compound C ₄ -C ₇ Conversion zone. Suitable reactions that may be performed in the first conversion zone 160 " may include oligomerization or aromatic alkylation. The first product, which may include the C ₄ -C ₇ -derived product, is released in the first conversion zone in line 162 "and enters stabilization column 180. And proceeds to a C ₄ -C ₇ -derived product in an FCC reactor, as in FIG.

The first and / or second conversion zone may comprise the oligomerization reactor 200 illustrated in FIG. The oligomerization reactor 200 can communicate downstream with the bottoms lines 144, 144 " of the LPG splitter collar 140 of FIGS. 1 and 3. The same or separate oligomerization reactor 200 can be used to separate the overhead lines 154,134'of the naphtha splitter columns 150 of Figures 1 and 2 and / or the overhead lines 134,134'from the process fractionation columns 130,130 ' , 154 ', respectively. In one embodiment, the diolefin in the bottom stream in line 144, 144 '', 154, or 154 'is transported into line 202 to effect a first reaction with the optional hydrogenation catalyst in selective hydrogenation zone 206 To be a saturated diolefin, which is not fully saturated with paraffins. Suitable conditions for the operation of the selective hydrogenation process are described, for example, in U.S. Patent No. 6,166,279 and U.S. Patent No. 6,075,173. Temperature to 20 ℃ (68 ℉ to 392 ℉) 200 ℃, at a pressure of 689 to 3447 kPa (g) (100 to 500 psig) and a space velocity (space velocity) 0.5 to 10 hr ^-1 is deposited on a support such as aluminum oxide The olefin and paraffin streams in the liquid phase in line 202 over the catalyst comprising at least one metal selected from the group consisting of nickel, palladium and platinum being formed and hydrogen in line 208 at 0.5 to 5 (mol / Diolefin moles, and molar ratios. Although only one is shown, more than one reaction zone may be used. Each reaction zone is capable of applying recycle (not shown) of reactor effluent to the reactor inlet at a recycle rate of 0 to 20 for the new olefin feed stream. The diolefin residue of the process may range from 1 to 100 wppm, depending on the degree of operation.

The effluent discharged from the selective hydrogenation reactor in line 210, along with the diolefins less condensed than line 202, may be recycled (recycle stream effluent in line 216, optional modifications in line 214, May be mixed with one, some, or all of the paraffinized diluent in the line 212 (which may be part of the paraffinized stream in line 184) and then mixed with one, some, or all of the paraffinized diluent in the oligomerization reactor (200). In the oligomerization reactor 200, the C ₄ olefin of line 144, the C ₅ -C ₇ olefin of line 154, or the C ₄ -C ₇ olefin of line 154 'or 154 " And oligomerization conditions of olefins to produce heavy olefins. The oligomerization reactor is shown as a downstream reactor, but an upstream reactor can also be applied.

The operating conditions of the oligomerization process include contacting the olefin and the liquid with a catalyst (e.g., SPA) or a sulfonated exchange resin (e.g., Amberlyst A-15, A-35, A-16, A-36, Dowex 50, ≪ / RTI > on a fixed layer of a substrate. Other devices may be used to limit the formation of heavy oligomers. These include the addition of a paraffinized dilution of line 212 to an oligomerization reactor, the recycling of the oligomerization reactor effluent of line 216 to the oligomerization reactor 200, and the use of a resin catalyst, when SPA catalysts are used , And addition of 0.1 to 3.0 percent by mass of the selectivity modification in line 214 to the oligomerization reactor. Avoiding the production of heavy olefins is not critical. Thus, one or all of the streams in lines 212-216 may be omitted.

Preferred operating conditions apply differently when using SPA catalysts and when using exchange resin catalysts. If SPA catalysts are used, the preferred temperature is 40 ° C to 260 ° C, more typically 75 ° C to 230 ° C, whereas when using an ion exchange resin catalyst, preferred temperatures are 0 ° C to 200 ° C, more typically 40 ° C To < RTI ID = When SPA catalysts are used, preferred pressures are from 689 to 8274 kPa (g) (100 to 1200 psig), more typically from 1379 to 6895 kPa (g) (200 to 1000 psig) The preferred pressure is 345 to 3447 kPa (g) (50 to 500 psig), more typically 1379 to 2413 kPa (g) (200 to 350 psig). This pressure can be kept below the range and therefore no additional compressor is required to lift it above the system pressure required by the optional hydrogenation reactor 206. The preferred space velocity is 0.5 to 5 hr < ^-1 > when operating with an SPA catalyst, When operating with an ion exchange resin catalyst, is from 0.3 to 20 hr <" ¹ >, depending on the performance of the oligomerization reactor, such as the olefin component and type. Other catalysts are also applicable.

The oligomerization reactor product is discarded from the effluent line 220 of the oligomerization reactor 200. A portion of the oligomerization reactor effluent can be recycled to the oligomerization reactor via the recycle line 216 to control the calorific value. A second portion of the oligomerization reactor product passes through process line 222 to flash drum 226 where an unreacted vapor stream and an oligomerization product-enriched liquid stream are fed. The unreacted vapor stream is vented through the vapor line 228 to the flash drum 226 for further processing. A portion of the vapor stream in line 228 may be recycled to the oligomerization reactor 200 via line 230 after condensation and compression. The sufficiently oligomerized product stream in line 232 is removed from the bottom of the flash drum 226. The purge in line 234 for removing paraffins from the unreacted vapor stream in line 228 may be combined with line 232 to supply line 236, which may be lines 162, 162 ' do.

In another embodiment, the first and / or second conversion zone may be an aromatic alkylation reactor 300, as shown in FIG. The aromatic alkylation reactor 300 can communicate downstream with the bottoms line 144, 144 " of the LPG splitter column 140 of FIGS. 1 and 3. The same or separate aromatic alkylation reactor 300 may be used to separate the bottom lines 134 and 134 'from the process fractionation columns 130 and 130' and / or the overhead lines (not shown) of the naphtha splitter column 150 of FIGS. 154, 154 '. In one embodiment, the diolefins in the overhead stream in the overhead lines 154, 154 'or in the lines 144, 144 " are conveyed to line 302 to produce diolefins without completely saturated diolefins with paraffins. A first reaction can be performed with a selective hydrogenation catalyst in a selective hydrogenation zone 306 for selective saturation. Suitable conditions for the operation of the selective hydrogenation process are described in FIG. Hydrogen is passed from line 308 to reactor 306.

A stream containing olefins and paraffins, exiting the selective hydrogenation reactor 306 in line 310, is injected into the alkylation reactor 300. In one aspect, a dryer (not shown) in line 310 can be used to remove water that can affect the catalyst and to lower the concentration. Other boundary layers can also be considered to eliminate the toxicity of the catalyst. Although an alkyl exchange reaction takes place in the alkylation reactor 300, the alkylation reaction is predominant. The alkylation reactor is shown as an upstream reactor for the aromatic stream, but a downstream reactor is also applicable. The streams in line 310 of olefins and paraffins are connected to a respective plurality of lines 312,324 entering the pre-bed spaces prior to entry into the catalyst beds 332, 334 and 335 in the alkylation reactor 300. [ 314 and 316, respectively. Catalyst layers 332, 334 and 336 contain alkylation catalysts for alkylating aromatic and olefins to produce alkylbenzenes. The aromatic feed stream in line 340 is fed to an alkylation reactor 300 where it initially mixes with olefins and paraffins from line 316 in pre-bed space 326 and into catalyst bed 336 . The aromatic feed stream in line 340 may be at least partially introduced downstream from the line 192 of Figure 1, 2 or 3, or from an external stream derived from the pyrolysis gasoline from the steam cracking unit, preferably after hydrotreating . Other aromatic stream feedstocks can be considered.

The effluent from the catalyst layer 336 is mixed with new olefins and paraffins from line 314 in the pre-bed space 324 and enters the catalyst bed 334 together. The effluent from the catalyst layer 334 is mixed with new olefins and paraffins from line 312 in the pre-bed space 322 and enters the catalyst bed 332 together. The process is repeated in the number of layers of the alkylation reactor 300. Although only three catalyst layers are shown in the alkylation reactor 300, more or less layers and additional reactors are applicable. The alkylated effluent of the alkylation reactor 300 is conveyed to the effluent line 342. The heat exchanger 344 can cool the effluent in line 342 to an ideal temperature. Although not all shown, the alkylation reactor effluent stream may be depressurized as it passes through the pressure regulating valve or may be atmospheric pressure as it passes through the pump. The effluent line 342 carrying the alkylated product and the unreacted paraffin can be a line 162, 162 ', 162' 'or 172.

Benzene is the most important representative compound of alkylatable aromatic compounds that can be used as the alkylation substrate in line 340. The aromatic feed stream may comprise from 5 to 99.9 mole percent of benzene. More generally, the aromatic compound may be selected from the group consisting of benzene, naphthalene, anthracene, phenanthrene, and substituted derivatives thereof. The most important classes of substituents based on the aromatic nuclei of alkylatable aromatic compounds are mono- or poly-alkyl moieties containing from 1 to 20 carbon atoms. Another important substituent is a hydroxyl moiety and an alkoxy moiety (wherein the alkyl group contains 1 to 20 carbon atoms).

A wide variety of catalysts can be used in the alkylation reaction zone. The preferred catalyst used in the present invention is a zeolite catalyst. The catalyst of the present invention can be used in combination with a refractory inorganic oxide binder. Preferred binders are alumina or silica. Suitable zeolites include beta zeolite, ZSM-5, PSH-3, MCM-22, MCM-36, MCM-49, and MCM-56. Beta zeolite is disclosed in U.S. Patent No. 5,723,710. A preferred alkylation catalyst is UZM-8. The FAU structure and the catalyst to be applied are appropriate. The zeolite may be present in an amount of at least 50% by weight of the catalyst, more preferably at least 60% by weight of the catalyst. However, when a zeolite is provided in a laminated spherical body or an enhanced surface, a much lower zeolite concentration is required.

The specific conditions under which the alkylation reaction is carried out depend on the aromatic compounds and olefins used. As the reaction is carried out at least in part in the liquid phase conditions, the reaction pressure is adjusted so that at least some of the olefins are retained in the liquid phase. The olefin feed in the gas phase is also suitable. For heavy olefins the reaction may be carried out at autogenous pressure. The pressure can be adjusted over a wide range from 101 to 13172 kPa (gauge) (1 to 1900 psig). For practical reasons, the pressure is usually in the range of from 1379 to 6985 kPa (gauge) (200 to 1000 psig), but typically in the range of 2069 to 4137 kPa (gauge) (300 to 600 psig). Suitable temperature ranges for olefins and alkylatable aromatic compounds in the C _{4 to} C ₇ range are 60 ° C to 400 ° C and the most useful temperature range is 90 ° C to 250 ° C. Reactant is generally adequate mass flow of a liquid hourly space velocity on the yield (liquid hourly space velocity) 0.2 to 50 hr ^-1, especially from 0.5 to 10 hr ^- pass through the alkylation zone to ^one. The ratio of alkylatable aromatics to olefins should be from 1: 1 to 20: 1, with a ratio of 2.0 to 1.0 being preferred.

Without further elaboration, it is believed that one skilled in the art can, based on the description above, practice the invention. The foregoing preferred specific embodiments are to be considered as exemplary only and are not to be construed as limiting the scope of the invention in any way.

In the above, unless otherwise stated, all temperatures are expressed in degrees Celsius, and all parts and percentages are parts by weight.

From the above description, those skilled in the art can readily ascertain the essential characteristics of the present invention, and can make various changes and modifications in accordance with the various uses and conditions without departing from the spirit and scope of the present invention.

Claims (10)

C ₄ olefins and paraffins and C ₅ -C ₇ olefins and paraffins to the conversion zone to convert C ₄ olefins to C ₄ -derived oligomers or C ₄ -derived alkylaromatics and to convert C ₅ -C ₇ olefins and C + ₆ in the step C ₅ -C ₇ olefin by the alkylation reaction of aromatic compounds comprising the steps of conversion of alkyl aromatic compounds derived from C ₅ -C _7, wherein the switching section is in the oligomerization zone or aromatic alkylation zone;
From C ₄ olefins and paraffins separating alkyl aromatic compound or oligomer of C ₄ C ₄ derived origin;
Separating C ₅ -C ₇ -derived alkylaromatics from C ₅ -C ₇ olefins and paraffins; And
Supplying an alkylaromatic compound derived from C ₄ -based oligomer or C ₄ -based alkylaromatic compound and a C ₅ -C ₇ -aromatic compound to a fluid catalytic cracking (FCC) reactor
≪ / RTI > wherein the olefin is converted to an oligomer or alkylaromatic compound. The process of claim 1, wherein the C ₄ olefin and the paraffin and the C ₅ -C ₇ olefin and paraffin pass through the same conversion zone. The process of claim 1, wherein the C ₄ olefin and the paraffin and the C ₅ -C ₇ olefin and paraffin pass through different conversion zones. 4. The method of claim 3, Method C ₄ olefin and paraffin are passed to the first conversion zone in the oligomerization zone. The process of claim 1 wherein the first conversion zone through which the C ₄ olefin and paraffin pass is an aromatic alkylation zone. C ₅ -C ₇ by passing a first stream of olefins and paraffins into a first conversion zone, C ₅ -C ₇ for switching the olefins to alkyl aromatics in C ₅ -C ₇ derived oligomer or C ₅ -C ₇ Origin Wherein the first conversion zone is an oligomerization zone or an aromatic alkylation zone;
Passing a second stream of C ₄ olefins and paraffins to a second conversion zone to convert C ₄ olefins to C ₄ -derived oligomers or C ₄ -derived alkyl aromatics, wherein the second conversion zone comprises an oligomerization zone Or an aromatic alkylation zone;
From C ₄ olefins and paraffins separating alkyl aromatic compound or oligomer of C ₄ C ₄ derived origin;
Separating C ₅ -C ₇ olefins and paraffins from C ₅ -C ₇ -derived oligomers or C ₅ -C ₇ -derived alkylaromatics; And
Supplying a; (fluid catalytic cracking FCC) reactor alkyl aromatic compounds of the oligomer derived from C ₄ or C ₄ and C ₅ -C origin of the alkylaromatic compound in the _7-derived oligomer or C ₅ -C ₇ Origin of flow cracking
≪ / RTI > wherein the olefin is converted to an oligomer or alkylaromatic compound. A process fractionation column for separating an overhead stream comprising a C ₃ rich overhead stream from a C ₅ rich bottoms stream;
An aromatic alkylation reactor in communication with the bottoms line of the process fractionation column and for the alkylation of olefins and C ₆ + aromatic compounds in the C ₅ rich bottoms stream;
A product column for communicating with said aromatic alkylation reactor and for separating alkylaromatic compounds from unreacted compounds from said C ₅ rich bottoms stream; And
A fluid catalytic cracking (FCC) reactor in communication with the bottom line of the product column
(FCC) feed, wherein the olefin is converted to an alkylaromatic compound. Claim 7, in communication with the overhead line of the process fractionation column, and C ₄ rich in liquefied petroleum gas in; Liquefied petroleum gas (LPG) overhead including a C ₃ rich overhead stream from (liquefied petroleum gas LPG) a bottom stream Further comprising a liquefied petroleum gas (LPG) splitter column for separating the stream. A process fractionation column for separating an overhead stream comprising a C ₃ rich overhead stream from a C ₅ rich bottoms stream;
Communication with the bottom line of the process fractionation column, and a first switch section for switching the C ₅ -C ₇ olefins to alkyl aromatics in the C ₅ -C ₇ derived oligomer or C ₅ -C ₇ Origin of the first switch A first conversion zone wherein the zone is an oligomerization zone or an aromatic alkylation zone;
A second conversion zone in communication with the overhead line of the process fractionation column and for converting C ₄ olefins to C ₄ -derived oligomers or C ₄ -derived alkylaromatics, the second conversion zone comprising an oligomerization zone or an aromatic alkylation A second conversion zone that is a zone;
A product splitter column communicating with the first conversion zone and separating the C ₅ -C ₇ -derived oligomer or the C ₅ -C ₇ -derived alkylaromatic compound from the unreacted compound; And
A fluid catalytic cracking (FCC) reactor in communication with the bottom line of the product splitter column
(FCC) feed, wherein the olefin is converted to an oligomer or alkylaromatic compound. delete

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