CA1094581A - Catalytic alkylation process - Google Patents
Catalytic alkylation processInfo
- Publication number
- CA1094581A CA1094581A CA269,953A CA269953A CA1094581A CA 1094581 A CA1094581 A CA 1094581A CA 269953 A CA269953 A CA 269953A CA 1094581 A CA1094581 A CA 1094581A
- Authority
- CA
- Canada
- Prior art keywords
- effluent
- liquid
- isobutane
- stream
- cooling
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C2/00—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms
- C07C2/54—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by addition of unsaturated hydrocarbons to saturated hydrocarbons or to hydrocarbons containing a six-membered aromatic ring with no unsaturation outside the aromatic ring
- C07C2/56—Addition to acyclic hydrocarbons
- C07C2/58—Catalytic processes
- C07C2/62—Catalytic processes with acids
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C2527/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- C07C2527/02—Sulfur, selenium or tellurium; Compounds thereof
- C07C2527/053—Sulfates or other compounds comprising the anion (SnO3n+1)2-
- C07C2527/054—Sulfuric acid or other acids with the formula H2Sn03n+1
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C2527/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- C07C2527/06—Halogens; Compounds thereof
- C07C2527/08—Halides
- C07C2527/12—Fluorides
- C07C2527/1206—Hydrogen fluoride
Abstract
(4888 A) IMPROVED CATALYTIC ALXYLATION PROCESS
ABSTRACT
In the process for the catalytic alkylation of isobutane with an olefin to produce alkylate, the liquid reactor effluent stream comprising a hydrocarbon mixture of alkylate, isobutene and inert alkanes is used to provide cooling to the various condensers in the alkylation process.
ABSTRACT
In the process for the catalytic alkylation of isobutane with an olefin to produce alkylate, the liquid reactor effluent stream comprising a hydrocarbon mixture of alkylate, isobutene and inert alkanes is used to provide cooling to the various condensers in the alkylation process.
Description
~ _ACX&ROVN~ O THE INV~NTION
`~ Catalytic alkylat~on o~ l~obutane 1~ well ~nown in the art9 b~ng the union Or an ole~ln wlth i~obutane ln ~he pre~cnce o~ an acid cataly~t to produce hlgh oct~ne branched chaln hydrocarbons (alXylate) Sor u~e in aviatlon gasollne and motoi ~uel. Sp~clrlcally~ the olefin i8 comblned wit~
: 15 lsobutar.e in the pre~ence o~ an acld catalyst ln a reactor and undQrgoes an cxoth~rmic r~action. The acid i~ then separated ~rom the reactor ef~luent. Arter acid separatlon the reactor e~luent then proceed~ to a serles o~ distlllatlon column~ to separate the inert alkanes, the unreacted l~obutane rOr recycle, ~md to recover the alkylate. Treating 18 al~o perrormed on ~ome o~ the e~rluent to remove resldual acld and undesired reac~lon products. A varlatlon of thl~
.' ~ ~, , . , . .
..
la~s~l process has been to use the vaporization of a portion of the reactor effluent to cool the reactor, see Hydrocarbon Processing, September, 1974, page 206.
There are several disadvantages with the present art alkyla-tion process. First, large amounts of coolant, usually water or air, are necessary to condense the overhead streams from the dis-tillation columns. Second, only a part of the reactor effluent is vaporized when cooling the reactor. This vapor is recovered as isobutane for recycle. The remaining liquid containing alkylate and a large amount of isobutane must then undergo treating to remove contaminants such as residue acid and then be distilled to separate the isobutane and alkylate. The larger this stream the larger the deisobutanizer column must be, and the more heat that is necessary to effect separation. The present invention reduces or eliminates these disadvantages while also making a substantial reduction in the energy required for the process.
In accordance with the present teachings, a process is provided for catalytic alkylation of isobutane with an olefin which comprises the steps of:
a) contacting the olefin with a molar excess of isobutane and inert alkanes in the presence of an acid catalyst in a re-actor to form a reactor effluent containing alkylate, isobutane, acid catalyst and inert alkanes;
b) separating the acid catalyst from the reactor effluent to form a separator effluent;
c) effecting a liguid vapor separation on the separator effluent to obtain a liquid bottoms stream containing isobutane and alkylate and an overhead vapor stream containing isobutane and inert alkanes;
t, ~,.~:i 109~581 d) distilling the liquid bottoms stream to separate alkylate product as a liquid bottoms product and isobutane as a vaporous distillation effluent;
e) passing a portion of the separator effluent prior to the liquid vapor separation step, as a cooling effluent in indirect heat exchange with the vaporous distillation effluent to condense isobutane thereln and to vaporize a portion of the cooling effluent;
and thereafter f) effecting the liquid vapor separation step on the cooling effluent.
In other words, the present invention relates to an improved continuous process for producing alkylate in which olefin and a molar excess of isobutane are reacted together in an alkylation zone in the presence of an acid to form a liquid effluent, the liquid effluent is removed from the alkylation zone, and liquid effluent so removed is subjected to processing to recover alkylate therefrom, the processing including vaporizing at least a portion of the liquid effluent to form vapors and thereafter condensing the vapors by cooling, the improvement in accordance with the present invention compris-ing cooling the vapors to be condensed b~ passing liquid effluent from-the alkylation zone in indirect heat exchange with the vapors.
.~
0 ; .
1094St~l (4~a8A) Usln~ the present inventlon, the ~mount of lsobutane that must be treated and reco~ered in the dlstlllatlon column 18 greatly reduced, coollng ~ater $~ no longer necessary for the dlstlllation column o~erhead conden~er, and the variou~ distillatlon column~ may be operated at substantlally lower pressures, enhanclng the separatlon process.
The central reature Or the lnventlon 1~ the use Or the reactor e~luent to pro~lde coollng to condenser~ ln the alkylation procc~s. By utllizlng the effluent ln thls ~snner~ sub~tantlal saYlng~ ln operatlng expenses are reallzed~ along wlth savlngs ln capltal lnvestment ~or ne~
u~lt8 .
~ The lnventlon 1~ best underRtood by reference to the drawlngs.
1~ DESC~IPTION OF THE DRAWINaS
Figure 1 sho~s a ~lmpll~led block dlagram Or the lnventlon.
Flgure 2 shows the alkylatlon proces~ Or the present lnventlon ln greater detall~
Flgur~ 3, whlch 1~ slmllar to Flgure 2, shows an embodlment Or the lnvention whereln pressure-reduclng Yal~es ar~ used on the reactor e~fluent and a ~aporous n-butane dr~w i8 remoYed from the delsobutanlzer column.
~lgure 4 shows ln greater detail a ~apor sy~tem wh~h may b~ used as the vapor 8y8tem lllu~trated in block in Flgur~ 2.
~ lgure 5 3how~ stlll another embodiment Or the present lnYention in accordanee wlth whlch the lnventive 4~
(4&8~ A) proces~ i~ practicea ln conJunction with an alkylation l~eaetOr producing ~oth a liquld errluent and a vaporou~
errluellt .
~ ererring to ~gure 1, olerln and lsobutane ~eed enter a reac~or w.lich cont~lns tlle acid catalyst. The strea~il leavin~ trle reac~or contaills acid cataly3t, alkylate, lsobutane an~ lnert alkane~. ~i.is strea~ is then 3ent to an Acid ~eparator, where the aci~ cat~lyst is separated from the hyarocar~on mi~ture anà returned ~o tlle ~eactor. 'ilne resultin~ ~-y~rocarbon 3nixture i5 then sent to one or more ~ondellsers to supply necessary coolln~. The use of this y~rocar~on n~ixture rOr cooling tne condensers is the in~ention. l'lle ef~luent from the Condensers then ~oes to tlle Vapor-Liquia Separator where isobutane ~s partially recovered as a va~or. ~y proc~3sing not ~howll in the drawing thls vapor is compressed, conderlsed an~ returned to the Reactor. r ~e liquid fro~ the Se~arator then continues to the ~eisobutanizer Column where isobutalle i~ distilled over~lea~ for recycle, ana alkylate product is recovered as a bottoMs stream.
- ~eferring to tAe .nore detalle~ Fi~ure 2, olefin and isobutane are comblned in line 101 and fed to a reactor 103 where the reactants are r~ixea wlth acid catalyst and reacted to for~ll alkylate. qlhe product leave~ the reactor throu~h llne 1~5 to the acld separator 107. Here the acid i~ ~eparate~ ~rom the hydrocarbon mixture and returned to the reactor through line 108. The hydrocarbon mlxture containlng alkylate, isobutane and lnert alkanes leaves the acld separator throug~ line 109.
The hydrocarbon m~xture goea to provide cooling ln lO.!t~S~
(48~8 A) the condensers throu~h lines 111 anli 112. ~eciflcally r~ferrinO to line 111~ it is seen how the present inventlon ls applied to the deisobutanizer column~ drocarbon mlxture is transrilitted through line 11l to condenser 115 where at least part o~ tl~e hydrocarbor~ ixture i5 vaporized to provide coolin~ in tne condenser. T.he hydrocarbon mlxture arter providing cooling is transr~littéd throu~h line 116 to the vapor-liquid separator 117. In the same manner coollng is supplled to other conden~ers such 2S other column condensers and compressor effluent condensers by taklng the hydrocarbon mixture throu~h llne 11~, vapori~ng at least part of the hydrocarbon mi~ture ln the condenser and transmittlng the condenser effluellt through line 11l~ to the vapor-llquld separator 117. In like manner t~e hydrocarbon mlxture is used to cool th~ reactor through line 110 J an~ is then - - transmltted throug~. line 113 to the vapor llquld se~arator.
In the vapor-liqul~ separator 117 a vapor-llquld Aeparatlon takes place. The vapor contalns prlmarlly lsobutane an~ inert alkanes~ and the llquld contalns isobutane and aikylates. The vapors are transmltted throu~h line 118 where the vapor ls compressed and condensed in a va~or system 119. .iormally ln the vapor syste~, 119 one or more columns are employed to remove the lnert alkanes, such as - propanes, from the lsobutane. ~he lso~utane stream is then sent through line 120 to a second vapor-llquid separator 121. The liqui~ iso~utane stream i~ returned to the reactor t~roug~ line 122 ~na the vapor ls returne~ to the vapor system through line 118.
The liquld ~rom the ~irst vapor-llquid separator lO!~ ~S81 (4888 A) 117 containlng lsobutane and alkylate then proceeds throu~h line 123 to the treatlng sectlon 125 where re~idue acid and acidlc compounds lrl the hydrocarbon mlxture are removed.
After treating, the llquid 18 tran~mitted throu~h llne 129 to the del~obutanizer column 131. Heat ls applled to the column throu~h llne 133. Isobutane iq dlstllled and exlts the top Or the colu~n as a vapor ln llne 135. Thl~ vapor ls condensed in the overhead condenser 115 and the condensed lsobutane 1~ then 8pllt ror rerlux to the column, and as recycle to the reactor through llne 137. The alkylate product la recovered 28 a llquid bottoms stream through line 139.
Figure 3, being slmllar to ~lgure 2, shows another embodlment of the invention. The hydrocarbon mixture contaln-15 lng alkylate, lsobutane and lnert alkPnes leaves the acldseparator 107 throu~h llne 109. The hydrocarbon mlxture then goes to provlde coollng ln the condensers throu~h lines 111 and 112. Referring to line 111, a pressure reduclng valve 141 18 located in front of column condenser 115. Thls valve malntalns the hydrocarbon mlxture in llne 111 as a liquid state. It al30 allo~s the downstream pressure o~ the hydrocarbon mlxture golng lnto condenser 115 and e~lting ln llne 116 to be reduced. The pressure i~ reduced surric~ently to permlt vaporlzatlon of the hydrocarbon mlxture ln condenser 115. Some vaporizatlon may occur between valve 141 and conaenser 115.- A slmllar valve 140 18 shown reduclng the pressure of the hydrocarbon mixture ln line 110 whlch provldes coollng to reactor 103. Other pressure-reduclng valves (not ~hown) may also be found ln llne 112 going to other condenser~.
10~4s~l (4~88 A) ~ ure 3 also shows tile dcl~o~utanlzer column 131 havlng a vaporous ~laestrealrl draw 142. Normal butane may be with~r~wn froF this column as a vapor ln llne 142 and condense~ ln colu~n conden~er 143. Typlcally, coolant i8 useà ln llne 144 to provlde coollng to condenser 143.
However~ the hyàrocarbon mlxture Or llne 112 wlth a suitable pressurereducing valve may also be used to provlde this coollng. A n-butane sidestream draw may ~e used in the other embodiments Or the present invention as well as the embodlment speciflcally illustrated ln Figure 3.
~ lgure 4 shows a vapor sy3tem which may be employed as vapor sy~tem 119 in the apparatus of Figure 2. The hydrocarbon mlxture arter ~elng used as a coolant 1~ transmitted through llne 113 to vapor-llquld separator 117 wherein a vapor-llquid ~eparatlon takes place. The vapors are transmltte~
through line 118 to compressor 145. l'he vapors are then compressed in the compre~sor and exit through line 146 to the compres~or effluent coldenser 147. Coollng 13 provlded througn line 148 to condenser 147 to condense the compressed vapor effluent. Tl~e coollng ~leans ~,ay be coollng water but ln another embo~imerlt of the lnvention the hydrocarbon m~xture o~ 112 wlti~ a suitable pressure reduclng val~e may al80 be used. The col~pressed condensed vapor efrluent exlts the ~ondenser through llne 149. A portion of thls co~pressed 2j condensed errluent is taken through-line 150 to distillation ~olumn 152. The remalnder i~ transmitted through llne 151 to a secona vapor-llquid separator 121, as also shown in Figure 2.
ri'ypically, di~tlllation column 152 is a deprvpanlzer column. Heat is applied to the column through line 153. Propane is distilled and exits the top of the column as a vapor in line 154. This vapor is condensed in the overhead condenser 155. In an embodiment of the invention, the hydrocarbon mixture of line 112, after pressure reduction is used to provide cooling to this condenser. The hydrocarbon mixture after providing cooling is transmitted through line 114 to the vapor-liquid separator 117 as shown in Figure 2.
The condensed propane from condenser 155 is then split for reflux to the column through line 156 and also removed as a product through line 157. The bottoms product of this column containing mostly isobutane is transmitted through line 158 to the vapor-liquid separator 121.
Still another embodiment of the present invention is illustrated in Figure 5. In this embodiment, the alkylation reaction is accomplished in such a way that a vaporous effluent as well as a liquid effluent are produced by the alkylation reactor. Such processes are well-known as illustrated, for example, in U.S. 3,187,066 to Nathan, which was reissue as 20 Re.26,060.
As illustrated in Figure 5, feed is passed into reactor 172 from conduit 174 where the alkylation reaction takes place.
The vaporous reaction effluent produced is withdrawn from reactor 172 via conduit 176 and passed to a conventional vapor system 178 for the recovery of isobutane. Liquid reaction effluent exits reactor 172 via conduit 180 and passes through condenser 182 where it partially vaporizes. The partially vaporized liquid reactor effluent then passes through conduit 184 to vapor liquid separator 186 where 10~4~1 ( 4888 A) vapor and liquld are separated from one another. Separated vapor travels v~a condult 188 to vapor system 178 where lt ls proce~sed along wlth the vaporous reactor erfluent produced ln reactor 172. The liquld stream pas~ing out o~
vapor ~iquld separator 186 travels vla conduit 190 to deiosobutanlzer 192 where it ls separated. Alkylate product ls recovered from delsobutanizer 192 via conduit 194 as column bottoms whlle isobutane-rlch vapors are taken orf delsobutanizer column 192 by means o~ conduit 196. I~obutane-rlch vapors in conduit 196 pass through condenser 182 where they pass ln lndlrect heat exch~nge relatlon with llquld reactor effluent obtained from reactor 172. Becau~e o~ the coollng effect created by the vaporlzation o~ llquld reactor ef~luent in con~en~er 182, the lsobutane-rich vapors ln condenser 182 condense to an lsobutane-rlch liquld stream.
A portlon Or thls lsobutane-rlch llquld stream ls sent to re~lux vla conduit 198 whereas the remainer is recycled to - reactor 172 via conduit 200.- Condensed lsobutane recovered from vapor system 178 ls also recycled to reactor 17? via 20 condult 202 as 111ustrated.
As appreclated by those skllled in the art~ vapor system 17~ normally includes a compressor ror ~acllltatlng condensatlon Or the vapor passed thereto. In accordance with the present lnventlon, thl8 compressor may lr desired be a multl-stage compressor, and moreover the vapor red ~rom vapor/liquld separator 186 or ~lmilarly vapor-llquld separator -121 Or Flg. 2 to thls compressor may also be red to the second or qubsequent stage~ rather than the rlrst stage o~
thl~ compre 80r.
The advantages o~ the present lnvention are manl~old.
(4888 A) 10945~31 Fir~t, because the ~eed to the deisobutanizer i3 reduced, the volume of the stream treated 1~ reduced. Typlcally this treating consl9t9 of a caustlc wash followed by a water wash. The size Or the caustic treater is decreased effecting a savlngs ln capital cost for the equipment requlred. A
second advantage is the size of the aeisobutanizer column.
Because a larger amount of isobutane is vaporized ln the reactor effluent, less has to be recovered in the dlstillatlon column. 5'his means a reduction in both the size of the column and the heat input nece~sary for operatlon. Stlll another advantage can be found by uslng the efrluent stream as the coollng medium for the overhead condensers located on the deisobutanizer and other distillation columns in the process, sucr. as a depropa~ er and debutanizer. The use Or ; 15 the effluent stream allows lower operatin~ temperatures and pressures for these colun~ls than could be reallzed u~lng water or alr. Also, ellr~llnation of water as a coolant means that the associated utllltles, such as a cooling tower, can be decreased in slze or eliminated. 'i'hls reduction in operatlng temperature and pressure of the columns ~erve~ to lncrease the relative volatllity Or the key components, meaning less energy lnput in the form o~ heat ls necessary to perform the separation required. ~hus a unlque savings i made in utllitles because tne water used to condense the overhead i3 no longer neces~ary, and the heat to the tower ~or separatlon ls reduced.
-(4a88 A) PP~FhRR~D D~SCRIPTION OF ~M~ODIM~NT
In the pre~erred concept Or this lnventlon thereactor effluent, after acld ~eparatlon, is ~ent to the overhead condenser~ on the distlllation columns ln the process. Thls concept is preferred because lower temperature~
can be achleved uslng the reactor effluent than by uslng coolin~ water. With lower temperatures and pressures ln the column9 the separatlon proce~ is greatly enhanced. I~ more than one condenser ls cooled by the effluent stream, they may be connected in elther paràllel or serle~ rashlon. It 18 pre~erred that they be connected ln parallel to mlnlmlze capltal C08t8.
Typlcally at least two dl~tillatlon columns are pre~ent, a delsobutanlzer for separatlng l~obutane rrom the alkylate product, and a depropanlzer to remove the li~hter propane from the i~obutane. In 30me cases a third column for separatlng butane from alkylate is also ~nvolved.
A varlant of thls lnvention 1~ to use the reactor erfluent stream in other locations ln the process that requlres coolln~, Thls may be ln addltlon to or exclusive - o~ coollng the overhead condenser~ on the dlstillatlon columns. Conden~ers are normally ~ound ln other locatlons om alstlllation columns, such as coollng the llquld bottoms product or condenElng a vapor slde~tream draw. For example, ln3tead Or havlng a debutanlzer column, butane may be removed ~rom the process as a ~apor taken from some point in the del~obutanlzer column. The reactor e~fluent may be used to condense this vapor to produce a liquld butane product.
Another varlant 18 to use the reactor erfluent to cool the ~ompressed vapor efrluent stream ~rom ths flrst 10945~1 ( 4888 A) vapor-llquid ~eparator. These compressed vapors contalnlng 180butane and some inert alkanes must be condensed berore they are ~ent to further dlstillatlon column~ to remove the lnert al~anes or back to the reactor as recycle lsobutane.
The reactor effluent may be used ln the vapor compressor effluent condenser, tnereby eliminating another u~age o~
coollng water.
It ls ant~clpated that this inventlon may be used in any catalytic alkylatlon process involvlng an acld catalyst. The acld catalysts that may be used are known ln the art, lncludlng but not llmlted to sulfurlc and hydro~luorlc acid. Pre~erred in the pre~ent lnvention ls the use of ~ul~uric acld cataly~t.
The reaction conditlon~ and parameters are unchanged by thl8 lnventlon. I~ormally the reactor ~ 8 operated between 1-200 p~lg, and a temperature between -lO to 50C. The olefln feed to the alkylatlon proces~ 1~ also known ln the ~i art~belng typlcally a hydrocarbon of 2-5 carbona and is not affected by the ~resent inventlon. ~iormally the compositlon Or the olefin ~eed depend~ on the specl~lc appllcatlon, but may comprlse propylene, butylenes or amylene3. The olerln reed may also contain varlous lnert alkanes, such as propane and butane. The olefln 18 mlxed with lsobutane either berore golng to the reactor or ln the reactor. Normally ~he hlgher the ratio Or lsobutane to ole~in in the ~eed stock the greater the yleld of alkylate. Thla external ratlo i8 u~u~lly ~bout 5:1 but can be 15:1 or higher. The pre~ent ln~entio~ takes adYantage ~ thl~ ratlo by recoverlng l~obutan~ ~or recycle ln a more ef~lclent and les~ costly 10~?45~'31 (4888 A) nanner than the present art. ~y uslng thls lnvention in existing units tllls ratio can be increased, thereby lmprovlng tlle oc~ane Or the proauct witllout being limitea by the slze of the delsobutanlzer.
As inalcatea above, the hy~rocarbon mixture belng u~ea to provide coolin~ may be passed through a pre~sure-reduclng valve prlor to its entry lnto the condensera lf ~eslred. The pressure 1~ reàuc~a sufflciently to permlt vaporization and affect greater cooling in the condenser.
The pressure may be reauced to a pressure of 1 psia to about 50 p~ia. It is pre~erred to reduce thl~ pressure to 3 p81g to about 5 psl~.
, ~P~CIFIC ~O~IM~hri' ~xample 1 and Co~;~arative ~xample A
1~ A com~uter slmulatlon was made Or an alkylation proces~ as depicted ln the ~yarocarbon Processlng rererence of September, 1974, page 206. Sulfurlc acld wa~ used a3 the acid cataly3t. l'he reactant feea to both examples 18 glven in Table I in barrels per ~tream day, being a cominatlon o~
lsobutane, butylene, and lnert alkanes.
TA~I~ I
~eactant Feed ~'o Alkylation Process Isobutane 3830 ~utylene 3090 Inert Alkane~ 1385 For comparlson, the amount Or product and lts -14_ ~0~? ~5~1 (4888 A) ootane number of 98.5 wa~ held constant for both examples.
q'he isobutano ln the reactlon zone wa~ held at 80 p~rcent Or the total ~eed plu8 recycle. ~ue to th¢ larger amounts Or lnert alkanes ehat are recycled ln the e~rluent rerrlgeratlon stream ln th~ pre~ent lnvention, thls has the e~rect Or lncreaslng the lsobutane/olef~n ratlo in th~ reactor. ~he other oper~tlng ~ondltions Or the reactor was the same ror both examples.
ComparatlYe ~xample A show~ the present art. ~he 10 reactor erf'luent arter acld separatlon was used to cool the reactor. A~ter coollng, the effluent stream was sent to the rlrst vapor-liquld separator. The ll~uld from thls ~eparator const~tuted the strea~ that was treated and sent as feed to the d~lsobutani2er column. Cooling water was used as th~
coollng medlum ln the-oYerhead condenser o~ this column.
In ~xample 1, showing the pre~ent invention, the reactor er~luent, ~n addition to cool~ng the reactor, wa~
sent ln a parallel manner to the overhead condenser of the dei30butanizer. After coollng, the reactor efrluent ~ras collected ln the rlrst vapor-llqu~ d separator. Table II
ohows th~ result~ Or these two e~amples. Quantitles ~hown aro barr31~ per stream day.
10~4~
(4888 A) rrA~L~ II
Com~arlson of Art Alkylatlon Wlth Invention CoirlparatlveExam~le 1 r xample AInventlon l . IC41n feed 3, ~3o 3, 830
`~ Catalytic alkylat~on o~ l~obutane 1~ well ~nown in the art9 b~ng the union Or an ole~ln wlth i~obutane ln ~he pre~cnce o~ an acid cataly~t to produce hlgh oct~ne branched chaln hydrocarbons (alXylate) Sor u~e in aviatlon gasollne and motoi ~uel. Sp~clrlcally~ the olefin i8 comblned wit~
: 15 lsobutar.e in the pre~ence o~ an acld catalyst ln a reactor and undQrgoes an cxoth~rmic r~action. The acid i~ then separated ~rom the reactor ef~luent. Arter acid separatlon the reactor e~luent then proceed~ to a serles o~ distlllatlon column~ to separate the inert alkanes, the unreacted l~obutane rOr recycle, ~md to recover the alkylate. Treating 18 al~o perrormed on ~ome o~ the e~rluent to remove resldual acld and undesired reac~lon products. A varlatlon of thl~
.' ~ ~, , . , . .
..
la~s~l process has been to use the vaporization of a portion of the reactor effluent to cool the reactor, see Hydrocarbon Processing, September, 1974, page 206.
There are several disadvantages with the present art alkyla-tion process. First, large amounts of coolant, usually water or air, are necessary to condense the overhead streams from the dis-tillation columns. Second, only a part of the reactor effluent is vaporized when cooling the reactor. This vapor is recovered as isobutane for recycle. The remaining liquid containing alkylate and a large amount of isobutane must then undergo treating to remove contaminants such as residue acid and then be distilled to separate the isobutane and alkylate. The larger this stream the larger the deisobutanizer column must be, and the more heat that is necessary to effect separation. The present invention reduces or eliminates these disadvantages while also making a substantial reduction in the energy required for the process.
In accordance with the present teachings, a process is provided for catalytic alkylation of isobutane with an olefin which comprises the steps of:
a) contacting the olefin with a molar excess of isobutane and inert alkanes in the presence of an acid catalyst in a re-actor to form a reactor effluent containing alkylate, isobutane, acid catalyst and inert alkanes;
b) separating the acid catalyst from the reactor effluent to form a separator effluent;
c) effecting a liguid vapor separation on the separator effluent to obtain a liquid bottoms stream containing isobutane and alkylate and an overhead vapor stream containing isobutane and inert alkanes;
t, ~,.~:i 109~581 d) distilling the liquid bottoms stream to separate alkylate product as a liquid bottoms product and isobutane as a vaporous distillation effluent;
e) passing a portion of the separator effluent prior to the liquid vapor separation step, as a cooling effluent in indirect heat exchange with the vaporous distillation effluent to condense isobutane thereln and to vaporize a portion of the cooling effluent;
and thereafter f) effecting the liquid vapor separation step on the cooling effluent.
In other words, the present invention relates to an improved continuous process for producing alkylate in which olefin and a molar excess of isobutane are reacted together in an alkylation zone in the presence of an acid to form a liquid effluent, the liquid effluent is removed from the alkylation zone, and liquid effluent so removed is subjected to processing to recover alkylate therefrom, the processing including vaporizing at least a portion of the liquid effluent to form vapors and thereafter condensing the vapors by cooling, the improvement in accordance with the present invention compris-ing cooling the vapors to be condensed b~ passing liquid effluent from-the alkylation zone in indirect heat exchange with the vapors.
.~
0 ; .
1094St~l (4~a8A) Usln~ the present inventlon, the ~mount of lsobutane that must be treated and reco~ered in the dlstlllatlon column 18 greatly reduced, coollng ~ater $~ no longer necessary for the dlstlllation column o~erhead conden~er, and the variou~ distillatlon column~ may be operated at substantlally lower pressures, enhanclng the separatlon process.
The central reature Or the lnventlon 1~ the use Or the reactor e~luent to pro~lde coollng to condenser~ ln the alkylation procc~s. By utllizlng the effluent ln thls ~snner~ sub~tantlal saYlng~ ln operatlng expenses are reallzed~ along wlth savlngs ln capltal lnvestment ~or ne~
u~lt8 .
~ The lnventlon 1~ best underRtood by reference to the drawlngs.
1~ DESC~IPTION OF THE DRAWINaS
Figure 1 sho~s a ~lmpll~led block dlagram Or the lnventlon.
Flgure 2 shows the alkylatlon proces~ Or the present lnventlon ln greater detall~
Flgur~ 3, whlch 1~ slmllar to Flgure 2, shows an embodlment Or the lnvention whereln pressure-reduclng Yal~es ar~ used on the reactor e~fluent and a ~aporous n-butane dr~w i8 remoYed from the delsobutanlzer column.
~lgure 4 shows ln greater detail a ~apor sy~tem wh~h may b~ used as the vapor 8y8tem lllu~trated in block in Flgur~ 2.
~ lgure 5 3how~ stlll another embodiment Or the present lnYention in accordanee wlth whlch the lnventive 4~
(4&8~ A) proces~ i~ practicea ln conJunction with an alkylation l~eaetOr producing ~oth a liquld errluent and a vaporou~
errluellt .
~ ererring to ~gure 1, olerln and lsobutane ~eed enter a reac~or w.lich cont~lns tlle acid catalyst. The strea~il leavin~ trle reac~or contaills acid cataly3t, alkylate, lsobutane an~ lnert alkane~. ~i.is strea~ is then 3ent to an Acid ~eparator, where the aci~ cat~lyst is separated from the hyarocar~on mi~ture anà returned ~o tlle ~eactor. 'ilne resultin~ ~-y~rocarbon 3nixture i5 then sent to one or more ~ondellsers to supply necessary coolln~. The use of this y~rocar~on n~ixture rOr cooling tne condensers is the in~ention. l'lle ef~luent from the Condensers then ~oes to tlle Vapor-Liquia Separator where isobutane ~s partially recovered as a va~or. ~y proc~3sing not ~howll in the drawing thls vapor is compressed, conderlsed an~ returned to the Reactor. r ~e liquid fro~ the Se~arator then continues to the ~eisobutanizer Column where isobutalle i~ distilled over~lea~ for recycle, ana alkylate product is recovered as a bottoMs stream.
- ~eferring to tAe .nore detalle~ Fi~ure 2, olefin and isobutane are comblned in line 101 and fed to a reactor 103 where the reactants are r~ixea wlth acid catalyst and reacted to for~ll alkylate. qlhe product leave~ the reactor throu~h llne 1~5 to the acld separator 107. Here the acid i~ ~eparate~ ~rom the hydrocarbon mixture and returned to the reactor through line 108. The hydrocarbon mlxture containlng alkylate, isobutane and lnert alkanes leaves the acld separator throug~ line 109.
The hydrocarbon m~xture goea to provide cooling ln lO.!t~S~
(48~8 A) the condensers throu~h lines 111 anli 112. ~eciflcally r~ferrinO to line 111~ it is seen how the present inventlon ls applied to the deisobutanizer column~ drocarbon mlxture is transrilitted through line 11l to condenser 115 where at least part o~ tl~e hydrocarbor~ ixture i5 vaporized to provide coolin~ in tne condenser. T.he hydrocarbon mlxture arter providing cooling is transr~littéd throu~h line 116 to the vapor-liquid separator 117. In the same manner coollng is supplled to other conden~ers such 2S other column condensers and compressor effluent condensers by taklng the hydrocarbon mixture throu~h llne 11~, vapori~ng at least part of the hydrocarbon mi~ture ln the condenser and transmittlng the condenser effluellt through line 11l~ to the vapor-llquld separator 117. In like manner t~e hydrocarbon mlxture is used to cool th~ reactor through line 110 J an~ is then - - transmltted throug~. line 113 to the vapor llquld se~arator.
In the vapor-liqul~ separator 117 a vapor-llquld Aeparatlon takes place. The vapor contalns prlmarlly lsobutane an~ inert alkanes~ and the llquld contalns isobutane and aikylates. The vapors are transmltted throu~h line 118 where the vapor ls compressed and condensed in a va~or system 119. .iormally ln the vapor syste~, 119 one or more columns are employed to remove the lnert alkanes, such as - propanes, from the lsobutane. ~he lso~utane stream is then sent through line 120 to a second vapor-llquid separator 121. The liqui~ iso~utane stream i~ returned to the reactor t~roug~ line 122 ~na the vapor ls returne~ to the vapor system through line 118.
The liquld ~rom the ~irst vapor-llquid separator lO!~ ~S81 (4888 A) 117 containlng lsobutane and alkylate then proceeds throu~h line 123 to the treatlng sectlon 125 where re~idue acid and acidlc compounds lrl the hydrocarbon mlxture are removed.
After treating, the llquid 18 tran~mitted throu~h llne 129 to the del~obutanizer column 131. Heat ls applled to the column throu~h llne 133. Isobutane iq dlstllled and exlts the top Or the colu~n as a vapor ln llne 135. Thl~ vapor ls condensed in the overhead condenser 115 and the condensed lsobutane 1~ then 8pllt ror rerlux to the column, and as recycle to the reactor through llne 137. The alkylate product la recovered 28 a llquid bottoms stream through line 139.
Figure 3, being slmllar to ~lgure 2, shows another embodlment of the invention. The hydrocarbon mixture contaln-15 lng alkylate, lsobutane and lnert alkPnes leaves the acldseparator 107 throu~h llne 109. The hydrocarbon mlxture then goes to provlde coollng ln the condensers throu~h lines 111 and 112. Referring to line 111, a pressure reduclng valve 141 18 located in front of column condenser 115. Thls valve malntalns the hydrocarbon mlxture in llne 111 as a liquid state. It al30 allo~s the downstream pressure o~ the hydrocarbon mlxture golng lnto condenser 115 and e~lting ln llne 116 to be reduced. The pressure i~ reduced surric~ently to permlt vaporlzatlon of the hydrocarbon mlxture ln condenser 115. Some vaporizatlon may occur between valve 141 and conaenser 115.- A slmllar valve 140 18 shown reduclng the pressure of the hydrocarbon mixture ln line 110 whlch provldes coollng to reactor 103. Other pressure-reduclng valves (not ~hown) may also be found ln llne 112 going to other condenser~.
10~4s~l (4~88 A) ~ ure 3 also shows tile dcl~o~utanlzer column 131 havlng a vaporous ~laestrealrl draw 142. Normal butane may be with~r~wn froF this column as a vapor ln llne 142 and condense~ ln colu~n conden~er 143. Typlcally, coolant i8 useà ln llne 144 to provlde coollng to condenser 143.
However~ the hyàrocarbon mlxture Or llne 112 wlth a suitable pressurereducing valve may also be used to provlde this coollng. A n-butane sidestream draw may ~e used in the other embodiments Or the present invention as well as the embodlment speciflcally illustrated ln Figure 3.
~ lgure 4 shows a vapor sy3tem which may be employed as vapor sy~tem 119 in the apparatus of Figure 2. The hydrocarbon mlxture arter ~elng used as a coolant 1~ transmitted through llne 113 to vapor-llquld separator 117 wherein a vapor-llquid ~eparatlon takes place. The vapors are transmltte~
through line 118 to compressor 145. l'he vapors are then compressed in the compre~sor and exit through line 146 to the compres~or effluent coldenser 147. Coollng 13 provlded througn line 148 to condenser 147 to condense the compressed vapor effluent. Tl~e coollng ~leans ~,ay be coollng water but ln another embo~imerlt of the lnvention the hydrocarbon m~xture o~ 112 wlti~ a suitable pressure reduclng val~e may al80 be used. The col~pressed condensed vapor efrluent exlts the ~ondenser through llne 149. A portion of thls co~pressed 2j condensed errluent is taken through-line 150 to distillation ~olumn 152. The remalnder i~ transmitted through llne 151 to a secona vapor-llquid separator 121, as also shown in Figure 2.
ri'ypically, di~tlllation column 152 is a deprvpanlzer column. Heat is applied to the column through line 153. Propane is distilled and exits the top of the column as a vapor in line 154. This vapor is condensed in the overhead condenser 155. In an embodiment of the invention, the hydrocarbon mixture of line 112, after pressure reduction is used to provide cooling to this condenser. The hydrocarbon mixture after providing cooling is transmitted through line 114 to the vapor-liquid separator 117 as shown in Figure 2.
The condensed propane from condenser 155 is then split for reflux to the column through line 156 and also removed as a product through line 157. The bottoms product of this column containing mostly isobutane is transmitted through line 158 to the vapor-liquid separator 121.
Still another embodiment of the present invention is illustrated in Figure 5. In this embodiment, the alkylation reaction is accomplished in such a way that a vaporous effluent as well as a liquid effluent are produced by the alkylation reactor. Such processes are well-known as illustrated, for example, in U.S. 3,187,066 to Nathan, which was reissue as 20 Re.26,060.
As illustrated in Figure 5, feed is passed into reactor 172 from conduit 174 where the alkylation reaction takes place.
The vaporous reaction effluent produced is withdrawn from reactor 172 via conduit 176 and passed to a conventional vapor system 178 for the recovery of isobutane. Liquid reaction effluent exits reactor 172 via conduit 180 and passes through condenser 182 where it partially vaporizes. The partially vaporized liquid reactor effluent then passes through conduit 184 to vapor liquid separator 186 where 10~4~1 ( 4888 A) vapor and liquld are separated from one another. Separated vapor travels v~a condult 188 to vapor system 178 where lt ls proce~sed along wlth the vaporous reactor erfluent produced ln reactor 172. The liquld stream pas~ing out o~
vapor ~iquld separator 186 travels vla conduit 190 to deiosobutanlzer 192 where it ls separated. Alkylate product ls recovered from delsobutanizer 192 via conduit 194 as column bottoms whlle isobutane-rlch vapors are taken orf delsobutanizer column 192 by means o~ conduit 196. I~obutane-rlch vapors in conduit 196 pass through condenser 182 where they pass ln lndlrect heat exch~nge relatlon with llquld reactor effluent obtained from reactor 172. Becau~e o~ the coollng effect created by the vaporlzation o~ llquld reactor ef~luent in con~en~er 182, the lsobutane-rich vapors ln condenser 182 condense to an lsobutane-rlch liquld stream.
A portlon Or thls lsobutane-rlch llquld stream ls sent to re~lux vla conduit 198 whereas the remainer is recycled to - reactor 172 via conduit 200.- Condensed lsobutane recovered from vapor system 178 ls also recycled to reactor 17? via 20 condult 202 as 111ustrated.
As appreclated by those skllled in the art~ vapor system 17~ normally includes a compressor ror ~acllltatlng condensatlon Or the vapor passed thereto. In accordance with the present lnventlon, thl8 compressor may lr desired be a multl-stage compressor, and moreover the vapor red ~rom vapor/liquld separator 186 or ~lmilarly vapor-llquld separator -121 Or Flg. 2 to thls compressor may also be red to the second or qubsequent stage~ rather than the rlrst stage o~
thl~ compre 80r.
The advantages o~ the present lnvention are manl~old.
(4888 A) 10945~31 Fir~t, because the ~eed to the deisobutanizer i3 reduced, the volume of the stream treated 1~ reduced. Typlcally this treating consl9t9 of a caustlc wash followed by a water wash. The size Or the caustic treater is decreased effecting a savlngs ln capital cost for the equipment requlred. A
second advantage is the size of the aeisobutanizer column.
Because a larger amount of isobutane is vaporized ln the reactor effluent, less has to be recovered in the dlstillatlon column. 5'his means a reduction in both the size of the column and the heat input nece~sary for operatlon. Stlll another advantage can be found by uslng the efrluent stream as the coollng medium for the overhead condensers located on the deisobutanizer and other distillation columns in the process, sucr. as a depropa~ er and debutanizer. The use Or ; 15 the effluent stream allows lower operatin~ temperatures and pressures for these colun~ls than could be reallzed u~lng water or alr. Also, ellr~llnation of water as a coolant means that the associated utllltles, such as a cooling tower, can be decreased in slze or eliminated. 'i'hls reduction in operatlng temperature and pressure of the columns ~erve~ to lncrease the relative volatllity Or the key components, meaning less energy lnput in the form o~ heat ls necessary to perform the separation required. ~hus a unlque savings i made in utllitles because tne water used to condense the overhead i3 no longer neces~ary, and the heat to the tower ~or separatlon ls reduced.
-(4a88 A) PP~FhRR~D D~SCRIPTION OF ~M~ODIM~NT
In the pre~erred concept Or this lnventlon thereactor effluent, after acld ~eparatlon, is ~ent to the overhead condenser~ on the distlllation columns ln the process. Thls concept is preferred because lower temperature~
can be achleved uslng the reactor effluent than by uslng coolin~ water. With lower temperatures and pressures ln the column9 the separatlon proce~ is greatly enhanced. I~ more than one condenser ls cooled by the effluent stream, they may be connected in elther paràllel or serle~ rashlon. It 18 pre~erred that they be connected ln parallel to mlnlmlze capltal C08t8.
Typlcally at least two dl~tillatlon columns are pre~ent, a delsobutanlzer for separatlng l~obutane rrom the alkylate product, and a depropanlzer to remove the li~hter propane from the i~obutane. In 30me cases a third column for separatlng butane from alkylate is also ~nvolved.
A varlant of thls lnvention 1~ to use the reactor erfluent stream in other locations ln the process that requlres coolln~, Thls may be ln addltlon to or exclusive - o~ coollng the overhead condenser~ on the dlstillatlon columns. Conden~ers are normally ~ound ln other locatlons om alstlllation columns, such as coollng the llquld bottoms product or condenElng a vapor slde~tream draw. For example, ln3tead Or havlng a debutanlzer column, butane may be removed ~rom the process as a ~apor taken from some point in the del~obutanlzer column. The reactor e~fluent may be used to condense this vapor to produce a liquld butane product.
Another varlant 18 to use the reactor erfluent to cool the ~ompressed vapor efrluent stream ~rom ths flrst 10945~1 ( 4888 A) vapor-llquid ~eparator. These compressed vapors contalnlng 180butane and some inert alkanes must be condensed berore they are ~ent to further dlstillatlon column~ to remove the lnert al~anes or back to the reactor as recycle lsobutane.
The reactor effluent may be used ln the vapor compressor effluent condenser, tnereby eliminating another u~age o~
coollng water.
It ls ant~clpated that this inventlon may be used in any catalytic alkylatlon process involvlng an acld catalyst. The acld catalysts that may be used are known ln the art, lncludlng but not llmlted to sulfurlc and hydro~luorlc acid. Pre~erred in the pre~ent lnvention ls the use of ~ul~uric acld cataly~t.
The reaction conditlon~ and parameters are unchanged by thl8 lnventlon. I~ormally the reactor ~ 8 operated between 1-200 p~lg, and a temperature between -lO to 50C. The olefln feed to the alkylatlon proces~ 1~ also known ln the ~i art~belng typlcally a hydrocarbon of 2-5 carbona and is not affected by the ~resent inventlon. ~iormally the compositlon Or the olefin ~eed depend~ on the specl~lc appllcatlon, but may comprlse propylene, butylenes or amylene3. The olerln reed may also contain varlous lnert alkanes, such as propane and butane. The olefln 18 mlxed with lsobutane either berore golng to the reactor or ln the reactor. Normally ~he hlgher the ratio Or lsobutane to ole~in in the ~eed stock the greater the yleld of alkylate. Thla external ratlo i8 u~u~lly ~bout 5:1 but can be 15:1 or higher. The pre~ent ln~entio~ takes adYantage ~ thl~ ratlo by recoverlng l~obutan~ ~or recycle ln a more ef~lclent and les~ costly 10~?45~'31 (4888 A) nanner than the present art. ~y uslng thls lnvention in existing units tllls ratio can be increased, thereby lmprovlng tlle oc~ane Or the proauct witllout being limitea by the slze of the delsobutanlzer.
As inalcatea above, the hy~rocarbon mixture belng u~ea to provide coolin~ may be passed through a pre~sure-reduclng valve prlor to its entry lnto the condensera lf ~eslred. The pressure 1~ reàuc~a sufflciently to permlt vaporization and affect greater cooling in the condenser.
The pressure may be reauced to a pressure of 1 psia to about 50 p~ia. It is pre~erred to reduce thl~ pressure to 3 p81g to about 5 psl~.
, ~P~CIFIC ~O~IM~hri' ~xample 1 and Co~;~arative ~xample A
1~ A com~uter slmulatlon was made Or an alkylation proces~ as depicted ln the ~yarocarbon Processlng rererence of September, 1974, page 206. Sulfurlc acld wa~ used a3 the acid cataly3t. l'he reactant feea to both examples 18 glven in Table I in barrels per ~tream day, being a cominatlon o~
lsobutane, butylene, and lnert alkanes.
TA~I~ I
~eactant Feed ~'o Alkylation Process Isobutane 3830 ~utylene 3090 Inert Alkane~ 1385 For comparlson, the amount Or product and lts -14_ ~0~? ~5~1 (4888 A) ootane number of 98.5 wa~ held constant for both examples.
q'he isobutano ln the reactlon zone wa~ held at 80 p~rcent Or the total ~eed plu8 recycle. ~ue to th¢ larger amounts Or lnert alkanes ehat are recycled ln the e~rluent rerrlgeratlon stream ln th~ pre~ent lnvention, thls has the e~rect Or lncreaslng the lsobutane/olef~n ratlo in th~ reactor. ~he other oper~tlng ~ondltions Or the reactor was the same ror both examples.
ComparatlYe ~xample A show~ the present art. ~he 10 reactor erf'luent arter acld separatlon was used to cool the reactor. A~ter coollng, the effluent stream was sent to the rlrst vapor-liquld separator. The ll~uld from thls ~eparator const~tuted the strea~ that was treated and sent as feed to the d~lsobutani2er column. Cooling water was used as th~
coollng medlum ln the-oYerhead condenser o~ this column.
In ~xample 1, showing the pre~ent invention, the reactor er~luent, ~n addition to cool~ng the reactor, wa~
sent ln a parallel manner to the overhead condenser of the dei30butanizer. After coollng, the reactor efrluent ~ras collected ln the rlrst vapor-llqu~ d separator. Table II
ohows th~ result~ Or these two e~amples. Quantitles ~hown aro barr31~ per stream day.
10~4~
(4888 A) rrA~L~ II
Com~arlson of Art Alkylatlon Wlth Invention CoirlparatlveExam~le 1 r xample AInventlon l . IC41n feed 3, ~3o 3, 830
2. IC4~1efin ratio ln reactor 1~.9 18.2
3. IC4 ln vapor from separator 25,945 52,594
4. Deisobutanlzer IC4 in ~eed 26,~99 15,741 IC4 ln overhead product 26,602 15, 344 condenser duty ~ 54.4 40.8 reboiler ~uty * ~3.o 47.2 column diameter (rt.) 11.3 9.8 l~M BTU/hr.
As shown ln Table II, rar more Or the isobutane (IC4) contained ln the reactor effluent 19 vaporlzed, allowing ~or a more e~ficient recovery. The present lnventlon reduces the amount of lsobutane ~eed to the delsobutanlzer by more than 40 percent~ thereby reducing both the slze Or thls col~mn and the utllitle~ required for dlst~llatlon.
ExamPle 2 Using the same feed composltion and reactor condltions Or example 1, example 2 shows the efrect Or coollng the overhead c9ndenser on the aeisobutanizer column wlth reactor e~fluent only. Coolln~ water was completely ellmlnated, and the refrigerant efrect Or the reactor er~luent allowed the pre~sure ln the del30butanizer coluFn to be reduced rrom 15Q
p~ig to 17 psig. This reductlon in pre~sure lmprove~ separation, and allowed the amount o~ heat needed ~or operatlon to be reduced to 35.7 ~ TU/hr., more than 40 percent less heat than was requlred ~or the present art ln Comparatlve Example A.
As shown ln Table II, rar more Or the isobutane (IC4) contained ln the reactor effluent 19 vaporlzed, allowing ~or a more e~ficient recovery. The present lnventlon reduces the amount of lsobutane ~eed to the delsobutanlzer by more than 40 percent~ thereby reducing both the slze Or thls col~mn and the utllitle~ required for dlst~llatlon.
ExamPle 2 Using the same feed composltion and reactor condltions Or example 1, example 2 shows the efrect Or coollng the overhead c9ndenser on the aeisobutanizer column wlth reactor e~fluent only. Coolln~ water was completely ellmlnated, and the refrigerant efrect Or the reactor er~luent allowed the pre~sure ln the del30butanizer coluFn to be reduced rrom 15Q
p~ig to 17 psig. This reductlon in pre~sure lmprove~ separation, and allowed the amount o~ heat needed ~or operatlon to be reduced to 35.7 ~ TU/hr., more than 40 percent less heat than was requlred ~or the present art ln Comparatlve Example A.
Claims (40)
1. A process for catalytic alkylation of isobutane with an olefin comprising the steps of:
(a) contacting said olefin with a molar excess of isobutane and inert alkanes in the presence of an acid catalyst in a a reactor to form a reactor effluent containing alkylate, isobutane, acid catalyst and inert alkanes;
(b) separating said acid catalyst from said reactor effluent to from a separator effluent;
(c) effecting a liquid vapor separation on said separator effluent to obtain a liquid bottoms stream containing isobutane and alkylate and an overhead vapor stream containing isobutene and inert alkanes;
(d) distilling said liquid bottoms stream to separate alkylate product as a liquid bottoms product and isobutane as a vaporous distillation effluent;
(e) passing a portion of said separator effluent prior to the liquid vapor separation step, as a cooling effluent in indirect heat exchange with said vaporous distillation effluent to condense isobutane therein and to vaporize a portion of said cooling effluent; and thereafter (f) effecting the liquid vapor separation step on said cooling effluent.
(4888 A)
(a) contacting said olefin with a molar excess of isobutane and inert alkanes in the presence of an acid catalyst in a a reactor to form a reactor effluent containing alkylate, isobutane, acid catalyst and inert alkanes;
(b) separating said acid catalyst from said reactor effluent to from a separator effluent;
(c) effecting a liquid vapor separation on said separator effluent to obtain a liquid bottoms stream containing isobutane and alkylate and an overhead vapor stream containing isobutene and inert alkanes;
(d) distilling said liquid bottoms stream to separate alkylate product as a liquid bottoms product and isobutane as a vaporous distillation effluent;
(e) passing a portion of said separator effluent prior to the liquid vapor separation step, as a cooling effluent in indirect heat exchange with said vaporous distillation effluent to condense isobutane therein and to vaporize a portion of said cooling effluent; and thereafter (f) effecting the liquid vapor separation step on said cooling effluent.
(4888 A)
2. The process of claim 1 wherein a portion of said cooling effluent is vaporized by reducing the pressure of said cooling effluent prior to indirect heat exchange.
3. The process of claim 1 including the step of removing residual acid impurities from said liquid bottoms stream of (c) prior to distilling said stream
4. The process of claim 1 wherein said condensed isobutane of (e) is recycled to said reactor.
5. The process of claim 1 including the steps of compressing and condensing said overhead vapor stream of (c) to produce a condensed overhead vapor stream.
6. The process of claim 5 including the steps of subjecting said condensed overhead vapor stream to liquid-vapor separation with the liquid from said separation containing condensed isobutane.
7. The process of claim 6 wherein said condensed isobutane is recycled to said reactor.
8. The process of claim 5 including the step of utilizing a portion of said cooling effluent of (e) to effect the condensation of said overhead vapor stream by passing a portion of said cooling effluent in indirect heat exchange therewith.
9. The process of claim 5 including the step of distilling a portion of said condensed vapor stream to remove inert alkanes therefrom and condensing the vaporous alkane effluent from the alkane distillation by passing said vaporous alkane effluent in indirect heat exchange with a portion of said cooling effluent.
(4888 A)
(4888 A)
10. The process of claim 9 wherein said inert alkane is propane.
11. The process of claim 1 wherein the distillation of said liquid bottoms stream of (c) includes the removal of normal butane as a vaporous sidestream and condensing said vaporous sidestream by passing it in indirect heat exchange with a portion of said cooling effluent of (e).
12. In a continuous process for producing alkylate in which olefin and a molar excess of isobutane are reacted together in an alkylation zone in the presence of an acid to from a liquid effluent, the liquid effluent is removed from said alkylation zone, and liquid effluent so removed is subjected to processing to recover alkylate therefrom, said processing including vaporizing at least a portion of said liquid effluent to form vapors and thereafter condensing said vapors by cooling, the improvement wherein said vapors are cooled by passing liquid effluent from said alkylation zone in indirect heat exchange with said vapors.
13. The process of claim 12 wherein liquid effluent passed in indirect heat exchange with said vapors partially vaporizes during said cooling.
14. The process of claim 13 wherein the pressure of the liquid effluent passed in indirect heat exchange with said vapors is reduced prior to said indirect heat exchange sufficiently to permit at least partial vaporization of said liquid effluent during said cooling.
15. The process of claim 14 wherein the liquid effluent passed in indirect heat exchange with said vapors passes directly from said alkylation zone through a pressure (4888 A) reduction valve and to indirect heat exchange relation with said vapors.
16. The process of claim 14 wherein processing of said liquid effluent includes distilling a liquid stream derived from said liquid effluent.
17. The process of claim 14 wherein processing of said liquid effluent includes distilling a liquid stream derived from said liquid effluent in a deisobutanizer to produce isobutane-rich vapors and alkylate-rich liquid bottoms, said heat exchange with liquid effluent.
18. The process of claim 17 wherein processing of said liquid effluent includes partially vaporizing said liquid effluent to form a liquid stream and a vapor stream, said liquid stream being fed to said deisobutanizer.
19. The process of claim 18 wherein partially vaporizing said liquid effluent is accomplished by passing said effluent in indirect heat exchange with the reaction mixture in said alkylation zone.
20. The process of claim 18 wherein liquid effluent from said alkylation zone is separated into a first portion and a second portion, the liquid effluent of said first portion being passed in indirect heat exchange with the reaction mixture in said alkylation zone, the liquid effluent of said second portion being passed in indirect heat exchange with said vapors to effect said cooling, the liquid effluents from said first and second portions thereafter being mixed with one another and passed to a vapor/liquid separator for separating said liquid stream and said vapor stream from one another.
21. The process of claim 19 wherein said vapor stream is condensed by cooling, said vapor stream being cooled by passing liquid effluent from said alkylation zone in indirect heat exchange with said vapor stream.
22. The process of claim 21 wherein a portion of the condensed vapor stream is fed to a depropanizer for removing propane therefrom by distillation, said depropanizer generating propane-rich vapors, said propane-rich vapors being condensed by said liquid effluent.
23. The process of claim 14 wherein processing of said effluent to recover alkylate includes recovering propane in vapor form by ditillation, the vaporous propane being condensed by cooling, cooling of said vapors propane being accomplished by passing liquid effluent from said alkylation zone in indirect heat exchange with said vaporous propane.
24. The process of claim 14 wherein processing of said liquid effluent includes at least partially vaporizing said liquid effluent to produce a liquid stream and a vapor stream, said vapor stream being separated from said liquid stream and thereafter condensed by cooling, said vapor stream being condensed by cooling by passing liquid effluent from said alkylation zone in indirect heat exchange with said vapor stream.
25. The process of claim 12 wherein the olefin is a hydrocarbon of 2-5 carbons.
26. The process of claim 12 wherein the olefin is propylene.
27. The process of claim 12 wherein the olefin is selected from the group consisting of butylenes or amylenes.
(4888 A)
(4888 A)
28. The process of claim 12 wherein the acid catalyst is sulfuric acid.
29. The process of claim 12 wherein said acid catalyst is hydrofluoric acid.
30. A process for catalyst alkylation of isobutane with an olefin comprising the steps of:
(a) contacting said olefin with a molar excess of isobutane and inert alkanes in the presence of an acid catalyst in a reactor to form a reactor effluent containing alkylate, isobutane, acid catalyst and inert alkanes;
(b) separating said acid catalyst from said reactor effluent to form a separator effluent;
(c) effecting a liquid vapor separation on said separator effluent to obtain a liquid bottoms stream containing isobutane and alkylate and an overhead vapor stream containing isobutane and inert alkanes;
(d) compressing and condensing said overhead vapor stream to produce a condensed overhead vapor stream;
(e) distilling a portion of said condensed overhead vapor stream to separate isobutane as a liquid bottoms product and inert alkane as a vaporous distillation effluent;
(f) passing a portion of said separator effluent prior to the liquid vapor separation step, as a cooling effluent in indirect heat exchange with said vaporous distillation effluent to condense the inert alkane therein and to vaporize a portion of said cooling effluent; and thereafter (g) effecting the liquid vapor separation step on said cooling effluent.
(a) contacting said olefin with a molar excess of isobutane and inert alkanes in the presence of an acid catalyst in a reactor to form a reactor effluent containing alkylate, isobutane, acid catalyst and inert alkanes;
(b) separating said acid catalyst from said reactor effluent to form a separator effluent;
(c) effecting a liquid vapor separation on said separator effluent to obtain a liquid bottoms stream containing isobutane and alkylate and an overhead vapor stream containing isobutane and inert alkanes;
(d) compressing and condensing said overhead vapor stream to produce a condensed overhead vapor stream;
(e) distilling a portion of said condensed overhead vapor stream to separate isobutane as a liquid bottoms product and inert alkane as a vaporous distillation effluent;
(f) passing a portion of said separator effluent prior to the liquid vapor separation step, as a cooling effluent in indirect heat exchange with said vaporous distillation effluent to condense the inert alkane therein and to vaporize a portion of said cooling effluent; and thereafter (g) effecting the liquid vapor separation step on said cooling effluent.
31. The process of claim 30 wherein the inert alkane is propane.
32. In the process for the catalytic alkylation of isobutane with an olefin, comprising:
(a) contacting the olefin, a molar excess of isobutane and inert alkane in the liquid phase in the presence of an acid catalyst in a reactor to react substantially all of the olefin thus producing a liquid stream containing the acid catalyst and a hydrocarbon mixture containing alkylate, isobutane and inert alkanes;
(b) separating the acid catalyst from the hydro-carbon mixture;
(c) separating in a vapor-liquid separator the hydrocarbon mixture of (b) to obtain a liquid bottoms stream containing isobutane and alkylate and a vapor overhead stream containing isobutane and inert alkanes;
(d) compressing and condensing in a compressor effluent condenser the vapor overhead stream of (c) to produce a condensed overhead vapor stream;
(e) distilling in one ore more distillation columns equipped with one or more column condensers, the liquid bottoms stream of (c) to separate alkylate product from isobutane or the condensed overhead vapor stream of (d) to separate the isobutane from inert alkanes, the improvement comprising: vaporizing part of the hydrocarbon mixture of (b) to provide cooling to one or more condensers utilized in steps (d) and (e).
(a) contacting the olefin, a molar excess of isobutane and inert alkane in the liquid phase in the presence of an acid catalyst in a reactor to react substantially all of the olefin thus producing a liquid stream containing the acid catalyst and a hydrocarbon mixture containing alkylate, isobutane and inert alkanes;
(b) separating the acid catalyst from the hydro-carbon mixture;
(c) separating in a vapor-liquid separator the hydrocarbon mixture of (b) to obtain a liquid bottoms stream containing isobutane and alkylate and a vapor overhead stream containing isobutane and inert alkanes;
(d) compressing and condensing in a compressor effluent condenser the vapor overhead stream of (c) to produce a condensed overhead vapor stream;
(e) distilling in one ore more distillation columns equipped with one or more column condensers, the liquid bottoms stream of (c) to separate alkylate product from isobutane or the condensed overhead vapor stream of (d) to separate the isobutane from inert alkanes, the improvement comprising: vaporizing part of the hydrocarbon mixture of (b) to provide cooling to one or more condensers utilized in steps (d) and (e).
33. The process of claim 32 wherein the column condenser is a condenser on an overhead vapor stream of the column.
34. The process of claim 32 wherein the olefin is a hydrocarbon of 2-5 carbons.
35. The process of claim 32 wherein the olefin is propylene.
36. The process of claim 32 wherein the olefin is selected from the group consisting of butylenes or amylenes.
37. The process of claim 32 wherein the acid catalyst is sulfuric acid.
38. The process of claim 32 wherein the acid catalyst is hydro-fluoric acid.
39. The process of claim 32 wherein the column condenser is a condenser on an overhead vapor stream of a deisobutanizer column.
40. The process of claim 32 wherein the column condenser is a condenser on an overhead vapor stream of a depropanizer column.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US65034176A | 1976-01-19 | 1976-01-19 | |
| US650,341 | 1976-01-19 | ||
| US742,949 | 1976-11-18 | ||
| US05/742,949 US4130593A (en) | 1976-01-19 | 1976-11-18 | Alkylation process utilizing the hydrocarbon phase from a reactor for condensing a vaporous distillation effluent |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1094581A true CA1094581A (en) | 1981-01-27 |
Family
ID=27095834
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA269,953A Expired CA1094581A (en) | 1976-01-19 | 1977-01-18 | Catalytic alkylation process |
Country Status (19)
| Country | Link |
|---|---|
| JP (1) | JPS52102207A (en) |
| AR (1) | AR224094A1 (en) |
| AT (1) | AT362040B (en) |
| AU (1) | AU505525B2 (en) |
| BR (1) | BR7700336A (en) |
| CA (1) | CA1094581A (en) |
| CS (1) | CS199659B2 (en) |
| DD (1) | DD128763A5 (en) |
| DE (1) | DE2701170A1 (en) |
| DK (1) | DK18277A (en) |
| FR (1) | FR2338236A1 (en) |
| IN (1) | IN145697B (en) |
| IT (1) | IT1091806B (en) |
| MX (1) | MX143073A (en) |
| NL (1) | NL7700528A (en) |
| NO (1) | NO770144L (en) |
| PT (1) | PT66084B (en) |
| RO (1) | RO79194A (en) |
| SE (1) | SE424441B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1103704A (en) * | 1977-10-26 | 1981-06-23 | Richard H. Jones | Catalytic alkylation process |
| US4189616A (en) * | 1978-02-02 | 1980-02-19 | Phillips Petroleum Company | Maximum utilization of energy in isoparaffin recycle in alkylation |
| JPS5538284U (en) * | 1978-09-05 | 1980-03-12 | ||
| US4214114A (en) * | 1979-01-26 | 1980-07-22 | Uop Inc. | Isoparaffin-olefin alkylation utilizing evaporative cooling in a reactor-depropanizer |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3544652A (en) * | 1966-07-15 | 1970-12-01 | Pullman Inc | Alkylation with sulfuric acid |
-
1977
- 1977-01-13 DE DE19772701170 patent/DE2701170A1/en not_active Withdrawn
- 1977-01-15 IN IN55/CAL/77A patent/IN145697B/en unknown
- 1977-01-17 DD DD7700196967A patent/DD128763A5/en unknown
- 1977-01-17 MX MX167718A patent/MX143073A/en unknown
- 1977-01-18 BR BR7700336A patent/BR7700336A/en unknown
- 1977-01-18 AT AT25677A patent/AT362040B/en not_active IP Right Cessation
- 1977-01-18 NO NO770144A patent/NO770144L/en unknown
- 1977-01-18 FR FR7701295A patent/FR2338236A1/en active Granted
- 1977-01-18 IT IT19408/77A patent/IT1091806B/en active
- 1977-01-18 CA CA269,953A patent/CA1094581A/en not_active Expired
- 1977-01-18 DK DK18277A patent/DK18277A/en not_active Application Discontinuation
- 1977-01-18 PT PT66084A patent/PT66084B/en unknown
- 1977-01-18 AR AR266229A patent/AR224094A1/en active
- 1977-01-19 AU AU21456/77A patent/AU505525B2/en not_active Expired
- 1977-01-19 RO RO7789089A patent/RO79194A/en unknown
- 1977-01-19 JP JP482377A patent/JPS52102207A/en active Granted
- 1977-01-19 SE SE7700557A patent/SE424441B/en unknown
- 1977-01-19 NL NL7700528A patent/NL7700528A/en not_active Application Discontinuation
- 1977-01-19 CS CS77366A patent/CS199659B2/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| JPS52102207A (en) | 1977-08-27 |
| FR2338236A1 (en) | 1977-08-12 |
| MX143073A (en) | 1981-03-10 |
| NO770144L (en) | 1977-07-20 |
| AU2145677A (en) | 1978-07-27 |
| JPS6121927B2 (en) | 1986-05-29 |
| FR2338236B1 (en) | 1981-11-20 |
| IN145697B (en) | 1985-01-05 |
| RO79194A (en) | 1982-10-26 |
| SE7700557L (en) | 1977-07-20 |
| DE2701170A1 (en) | 1977-07-28 |
| IT1091806B (en) | 1985-07-06 |
| PT66084A (en) | 1977-02-01 |
| DK18277A (en) | 1977-07-20 |
| PT66084B (en) | 1978-06-26 |
| AR224094A1 (en) | 1981-10-30 |
| AU505525B2 (en) | 1979-11-22 |
| NL7700528A (en) | 1977-07-21 |
| ATA25677A (en) | 1980-09-15 |
| CS199659B2 (en) | 1980-07-31 |
| BR7700336A (en) | 1977-09-20 |
| AT362040B (en) | 1981-04-27 |
| SE424441B (en) | 1982-07-19 |
| DD128763A5 (en) | 1977-12-07 |
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