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„Ey-23194@ -4
Y H. c. MAYLAND
ALKYLATIQN
’ 2,494,393
OF PARAFFIN HYDROCARBONS
Filed July 24“, 1942
v FRESH
2 Sheets-Sheet 1
FR
/
July 23, 194e.
H. c. M_AYLAND '
2,404,393
ALKYLATION OF PARAFFIN HYDROCARBONS
Filed July 24, 1942
2 Sheets-Sheet 2
œ
0
@.N@
_o
@ai
Patented July 23, 1946
2,404,393 l
UNITED STATES PATENT oFFlcE '
2,404,393
ALKYLATION OF PARAFFIN
HYDROCARBONS
Harrison C. Mayland, Chicago, Ill., assignor to
Universal Oil Products Company, Chicago, Ill.,
a corporation of Delaware
Application July 24, 1942, Serial No. 452,122
6 Claims. l (Cl. 26g-683.4)
1
2
When hydrogen fluoride catalysts are used to
effect alkylation, certain organic materials are
formed in addition to the alkylation products
0f the reaction which tend- to accumulate in the
catalyst phase and which serve effectively as 'or
ganic diluents for the catalyst. The nature of-
This invention relates to the alkylation of hy
drocarbons in the presence of a hydrogen ñuoride
catalyst.
It is more particularly concerned with an im- ‘
proved process for the production of higher mo
lecular weight isoparañins by the alkylation of
the organic diluent formed in the alkylation re
lower boiling isoparaflins with oleflns in the pres
action is not known clearly, but it is believed that
in some cases at least higher molecular Weight
ence of a hydrogen fluoride catalyst wherein the
concentration of hydrogen fluoride is controlled
within a preferred range in order to obtain the 10 alkyl fluorides, particularly those having 6 or more
carbon atoms per molecule, are present as well as '
optimum product quality.
highermolecular weight -polymers and organic
The production of higher molecular weight iso
fluorine-containing complexes.
parafdns having valuable anti-knock properties
of considerable importance in the refining in
dustry. A convenient source of such hydrocar
bons is the catalytic alkylation of low boiling iso
paraii'ins such as isobutane and isopentane with
normally gaseous olefins such as propylene and
the butylenes. Large quantities of these hydro
carbons are available from the cracking of pe
troleum oils and from the natural gasoline in
dustry.
The alkylation of isoparaflins utilizing a liquid l
y
As the alkylation reaction is conducted ccn
and therefore suitable for use in aviation fuels is
16
tinuously with recycling of the separatedused
catalyst, a substantial portion of the organic
diluent formed remains dissolved or dispersed
in the catalyst phase and is therefore continu
ously recycled within the system. It is thus pos
20 sible for the organic diluent content of thecat
alyst to build up with continued use and theeffective hydrogen fluoride concentration is there- .
by reduced.
Myinvention contemplates controlling the ac.
catalyst, such as hydrogen fluoride, is ordinarily 25 cumulation of organic diluent in the’catalyst>
conducted by introducing the hydrocarbon charg
ing stock and catalyst into a mechanically agi
tated reaction Zone or any reaction zone suitable
phase by any convenient method of control
whereby to vcontain the effective hydrogenfluo
ride concentration within the most desirable
for effecting intimate contact between the hydro 30 range as hereinafter described. One method of
carbons and catalyst. The hydrocarbon-catalyst
controlling the accumulation ofv organic diluent
mixture is maintained at the desired tempera
comprises withdrawing a portion of the used cat
ture, pressure, and time of contact, and it is pref
alyst from the system and replacing itwith rela
erable that a substantial molecular excess of
tively uncontaminated catalyst such as fresh hy
isoparaffins over olefins be maintained through
drogen fluoride or regenerated catalyst having
35
out the entire reaction. The reaction mixture is
a higher effective concentration of hydrogen fluo- ,
withdrawn and is introduced into a separation
ride.
.
zone which ordinarily will comprise a settler.
The lower used catalyst layer is recycled from the
Although under some alkylation conditions
using a mineral acid catalyst such as sulfuric acid
or hydrogen fluoride, it‘is desirable to maintainv
40
being preferably withdrawn from the system and
the acid concentration as high as possible, e. g.,
introduced into a catalyst regeneration zone. T_he
by utilizing the highest acid replacement rate,`
upper hydrocarbon layer from thersettler is sub
that is economically feasible, I have' now found
settler to the reaction zone, a portion thereof
jected to fractionation for the recovery of gaso
line boiling range products and for the separa
that good results may be obtained at relatively '
acid concentrations when using a hydrogen
tion- 'of unconverted isoparaffins which may be 45 low
fluoride
catalyst. I have further discovered that
recycled to the reaction zone.
'
2,404,393
3
in many cases improved results may loe-obtained
by ‘controlling the hydrogen iiuoride dilution .
Within a relatively critical range wherein the .
optimum quality of alkylation products is ob
tained.
In one specific embodiment my invention com
prises an improvement' in thealkylation of iso
paraflins with oleñns in the presence of a hydro
` gen fluoride catalyst wherein the hydrocarbon
reaction products are separated from the used
`catalyst, said separated hydrocarbon reaction
products are subjected to fractionation, at least
‘ a portion of 'said used catalyst is returned to the
i alkylation zone, and used catalyst is withdrawn
1 from the system and replaced with catalyst hav
1 ing a higherreffective¿concentrationgof'hi/drogen.;
iluOride, saidiirhprovement comprising-the step'
lof controlling the withdrawal of used catalyst
is used throughout this speciñ'cation and appended
claims, it lis intended to include catalysts where
in hydrogen ñuoride is the essential active ingre
dient. Thus it is Within the scope of my inven
tion to employ catalysts containing relatively
minor amounts of other materials in addition to
hydrogen fluoride. For example, the hydrogen
iluoride catalyst may contain minor quantities
of Water. While ordinarily commercial “anhy
drous” hydrogen ñuorîde will be charged to the
alkylation system, it is possible to have as high
as about 10 to 15% water‘present in the cata
lyst.- Excessive dilution with Water, however, is
undesirable since it tends to reduce the alkylating
activity of lthe catalyst. Other substances such
as :boronptriñuoride whichigmay promotefthe cata
lytic activity of hydrogenI fluoride in" alkylation
reactions may also be present.
The alkylation of isoparainns with oleñns in
:ñuoride whereby to maintain the concentration 20 thepresence vof a hydrogen ñuoride catalyst may
of hydrogen fluoride in the catalyst phase'within.. . . beLconducted' at a temperature of from about
and the addition of more concentrated hydrogen .
the range wherein alkylation products of opti
‘mum quality are obtained.
In Fig. 1 is shown a schematic; flow 'diagram'v`
. `of the type of alkylation process to which my'
invention is related.
Fig. 2 illustrates graphically the limitations on
0° F., to about 200° F., although the reaction
temperature is preferably and more conveniently
held‘within -the range of from about 50° F., to
about 150° F.' The- pressure on the alkylation
' systemisordinarily just high enough to insure
that thehydrocarbons and catalyst are substan
,the useful degree of the dilution of the’catalysttially
the liquid phase. The reaction may be
phase.
subjected to further control by means of the
Referring. to„-Fig.- f1; a..1’r.esh`.hydrocarbon` feed 30 _ space -time -which isdeñnedas' thevolume. ,offcat
comprisingja-eparaiiin-.oleñnmixture: wherein iso
alystA within the.- contacting Zone ;» divided - by, the parañins» area preferably;v present . in substantial
volume rate 10er minute of hydrocarbon-react-v
molar.- excess-_» over. the: oleI-lns-` is introduced
ants charged to the zone. Usually thespace--time
îthrough-.lined - into >alkylation zone 2.. This zone
Willlie Within the .range of from.»about 5 -to about
may; comprise-any;y convenient arrangement. of . w Cil 80 minutes, although; this irange «may inv certain">
equipment“‘.orïapparatus,capable. of effecting-inti
cases be-extended :in either direction. -. Itis-prei.-`mate: contacting;l ofv the? hydrocarbon reactants.
erable-‘to maintain atall. timesA aÃ~` substantial..
and. catalyst. . A-.fresh.. liquid hydrogen . ñuoride
' catalyst yis introduced ¿throughline .3, Alkylation`
molarexcess of.isoparafñns-over oleñns-in the
alkylation'zone, -e;.g., from 4-:1 to 10:1 .or higher.
zonef2:is..preferably operatedat apressure such 40
The alkylation of isopara?linswvitholeñns,uti»
that .-.the catalyst. andhydrocarbons. are.- maine'
lizing hydrogen iluoride-.catalysts is, particularly
tained substantially in. the-liquid phase..
important in: the.- case-v of'. the :alkylation ..of'"iso-The reaction Amixture :passes .through line «A into
butane with.norrnally gaseous oleñnsf such asV
separationzone . 5_.which may conveniently ., com7
propylenefor. butylene which are readily; availe
prise. a.. settling.. zone; Used. hydrogen fluoride. - able-insubstantial quantities. fromordinary ref
catalyst-is removedmthrough . line I 6 ; and intro
lining 4sources.. However; kthe process-.may `also l.be`
ducedin . part-.into_regeneration zone..7. A sub
applied. .to normallyv liquid .isoparaiiinsïandznorf
stantial.; portion of.. the. used hydrogen fluoride
mally liquid .oleñns It .is..also.zpossibleI to. employ
catalyst-removed throughline 6 is recycled' by
mixtures of the normally> liquid andnormally
means of line 8'to> the alkylationY zone. 2.
gaseous hydrocarbons as reactants.
generationzone. 1 may comprise any4 eiïective
The .term “crude alkylate’? as `.used in .this speci
means;eï‘g;,‘ aheating 'or' distillation‘zone; where
fication is` intended to designate the totalstaf
by puriñed hydrogen ñuoride may be separated
bilized: hydrocarbonY reaction products.- ofA the
from ‘ the = organic“ contaminants present' in the
used: catalyst: Water may also be rerlrioved'fron'il
the` used acid' in this zone.`
The- regenerated
acid'is-tI'í'en-‘WithdraWn to' storage through line
IUT-or lmay berecycled through line` l l vtothe al
kylatiònïzone.> The organic’contaminants or- re-'-«
sidua-l- material ' which " remain“ after ~' the recovery 60
of purified hydrogenlilu'oride xfrom lthe 'used' cata- ~
lysti‘are - withdrawn from theI regeneration zone»
thr'oughlline ‘9.1
'
y
process; and it thus. includes. not-:only ,thegavia-tion' .
gasoline fraction .but also the higherboihngprod.- »
uctsof V,the_.reaction.
To illustrate more definitely the»~natureof§my`
invention I now- refer tothefollowingtable-which:l
includes experimental. data obtained- in twelve
alkylationv runsl using, a substantially» anhydrous .
hydrogen ñuoride. catalyst and. a hydrocarbon.
charging stock. having the --followingapproximate -
molall composition: 4%. isobutylene,._ 9%. n.-bu-»
The '-sep'arated‘hydrocarbon phase passes :from
zone-5 bysmeans of line `rl2‘.ir1to lfractionation zone 65 andheavier. Theapparatusfused was arranged.~
I3.
Light hydrocarbon gases of the process are>`
recoveredihroughlline: I8.-` A low'boiling uncon
vertedfzisoparaiiinï. stream' .suchf .asl ' isobutaneY may
befre'coveredz' throughîlineî M“- and'is preferably
Y recycled; by.“ means Áofîiline; I5: to -alkylation-zonef f
21;. SaturatedM gasoline boiling; range hydrocar--bonsiaresremoved “through line- l 6, and the :higheri
boiling ¿hydrocarbon reaction .products are recov
eredthrough. line .-I 7.
'
in `substantially. the same manner as shown-_iinI
Fig.-` 1,. andcomprised essentiallya.mechanically
agitated reaction zone of theßturbofmixer type,~..
means. for. charging,fresh_hydrogen;iluoride and.`
hydrocarbon reactants-_` thereto»,v a? settling; zone.
for» the separation` of used. catalyst fromfthe hy,-4
drocarbonreaction products, afractionation zone:
for fractionating-.said hydrocarbon reaction .-prod- à
nots, vmeans >for. recycling> the usedcatalyst ».from;
ïBythe-termßhydrogen ñuoride eatalyst’.’ which 5 ' the settling zone to thereaction zonefand .mea-ns.->
¿2,404,393 '
6
5
from the system.
,
such as space time, temperature,- composition of
for'withdrawing a portion of the used catalyst
the fresh charging stock and the combined feed,
‘
Run No.
l
Series..
2
3
_.
4
5
6
A
7
8
9
10
11
. B
C
0. 0
4. l
9. 3
70. 0
9.1
69. 3
0. 0
4. 1
9. 3
70. 0
l. 7
3. 8
9.1
69. 3
1. 3
4. 1
8.7
69. 7
_.
15. 9
15. 3
15.9
15. 3
15.6
05+
___________ __
i-Parañin/oleiìu ratio ................................... -_
0.7
5. 2
0. 8
5. l
0. 7
5. 2
0.8
5. 1
0.6
5. 3
i-Cll’ïl’m
n~C4H1o..__
___-.
-___
Conditions:
Space time, mim...
............. _.
Press., p. s. i. gage..
_____________ __
Temp., °
............ _.
_.
36
1. 7
3. 8
l
35
36
l
36
54
i
53
|
50
9
‘
1l
100
Vol. ratio, catalyst/hydrocarbon, 1n reaction zone.
_ 1. 1
Catalyst withdrawal rate, cc./hr .... __
_ 12.1
Catalyst addition rate, cc./h _______ __ 20. 0
R. P. M. of agitator in contacting zon
Analysis of catalyst phase:
`
Total titratable acidity, wt. per cent ................... _- 86. 8
l. 2
8. 4
6. 0
1. 0
3.1
5.5
|
12
l
l1
150
..... _'. .............. _.
Water, wt. per cent .................... ._
R l(1)1rganic diluent, wt. per cent ________________ _.
es ts:
A. S. T. M. Octane No. 0f 275° F. E. P. a1ky1ate.__.
61
.
12
50
1.1
1. 4
1. 2
2. 4
3. 3
7. 2
1750
1. 0
1. 9
4.0
,
1.1
1.1
3. 0
1.0
0.9
0. 9 96. 6
310 102.0
1. 2
1.4
4l. 4 13. 3
48.0 16.0
3500
1. 2
9. 5
11. 0
81.1
73. 2
66. 6
85.3
88. 7
79. 5
1. 9
24. 9
4. 0
29. 4
2. 7
12.0
1.1
26. 0
69.4
1.1
29. 5
92. 1
2.0
16.9
76. 7
1.0
22. 3
72. 9
_ 2. 6
_ 11.1
1.2
6. 7
1.2
10.1
l. 2
19.3
73.1
1. 2
25. 7 ,
._ 92. 3
92. 3
92. 7
92. 9
92.1
91.4
92. 7
92.4
92. 4
92.3
92. 5
92.7
- .
22
30
84
198
60
91
162
176
7
18
56
Vol. 275° F. E. P. alkylate/vol. catalyst withdrawn ..... __
20
27
75
171
54
82
144
153
7
17
51
58
Bronline No. of crude alkylate ____ _r ................... _.
0.1
0.1
0.1
0.2
0.1
0.1
0.2
0.1
0. 1
0.1
0. l
____ __
. Vol. crude alkylate/vol. catalyst withdrawn ______ ._
degree of mixing of reactants and catalyst, water
content ofthe catalyst, etc. The effect on the
location of the optimum acidity range caused by
changing other process variables may be illus
trated by comparing the curves for series A and
Series A comprising runs 1, 2, 3 and 4 was made
at 100° F., 36 minutes space time and 1750 R. P. M. '
on the mechanical agitator in the reaction zone.
In series B comprising runs 5, 6, 7 and 8 the
space time was .increased to an average value of
B which were made at space times of 36 and 55
about 55 minutes with all other conditions the
same. Series C comprising runs 9, 10, 11 and
12 was made at 50° F., an average space time of
about 11 minutes, and 3500 R. P. M. on the
mechanical agitator. The four tests in each se
ries were made at decreasing values of total
minutes, respectively. The .major effect under the
conditions of the two series was merely a general
decrease in the octane number level of the prod
uct, as the space time was increased over the
range of 36 to 55 minutes. However, in the case
of series C‘ the space time was decreased, the tem
titratable acidity in the catalyst phase in order
to illustrate the effect of the hydrogen fluoride
concentration under each set of conditions.
It can be seen by examining the data for each
series that as the total titratable acidity of the
catalyst phase in the reaction system decreases,
the volume of crude alkylate produced per vol
ume of used catalyst withdrawn from the system
increases markedly. Substantially the same ef
fect is noted in terms of volumes of 275° F., E. P.
alkylate produced per -volume of used catalyst
withdrawn from the system. It is apparent, then,
that a considerable economic advantage accrues
by operating at a relatively low titratable acidity
since the quantity of desired product obtained at
a given hydrogen fluoride replacement rate or
a given hydrogen fluoride regeneration cost is
substantially improved.
`
l
However, I have found as a result of experi
mental tests that there are limitations on the
66
perature was decreased, and the degree of mixing
4.
(as a function of the agitator speed) was in
creased with Vthe net result that the optimum
range of total acidity was definitely displaced in
the direction of higher hydrogen fluoride concen
trations. In practical terms this means a higher
regeneration rate or catalyst replacement rate is
required.
While it is thus not possible to establish they
optimum range of total acidity which is applicable
1n all cases, it has been found that for many cases,
e. g., when alkylating isobutane with propylene,`
butylenes, or amylenes, the desirable total acidity
will fall within the broader range of from about 65
to about 95%. Moreover, when'isobutane is al
kylated with normally gaseous oleiins in the pres
ence of a hydrogen fluoride catalyst under sub
stantially liquid phase conditions and at tempera
tures of from about 50° F., to about 100° F., or
useful degree of the dilution of the catalyst phase 60 slightly higher, the optimum octane number prod
ucts will be obtained at a total acidity within the
since with too great a dilution the quality of the
range of from about 70 to about 85%.
product is adversely affected. This fact is illus
It should be noted that the titratable acidity
trated in Fig. 2 wherein the Weight per cent
of the catalyst phase within the reaction system
total acidity of the catalyst phase has been plotted
against the A. S. T. M. octane number of the
275° F., E. P. alkylate product for all three series.
It will be seen that for each of the three series
_ there is a deñnite optimum range of total acidity
wherein the highest octane number product is
obtained.
~
'
It is not possible to establish definitely a rela
tively narrow range of total acidity which will
give optimum results in all cases. The exact op
timum range for any case may depend to a con
is an eñective measure of the free hydrogen fluor
ide concentration. However, it is not necessarily
a true measure of the catalytic activity of the
catalyst phase unless the complete composition
of the phase is known. From the data obtained
in these runs, it will be seen that the dilution of
the hydrogen fluoride was accomplished largely by
the accumulation of organic diluent during the ,
alkylation reaction. If the same effective dilu
tion of the hydrogen iluoride were obtained by the
siderable extent on the other process variables 75 addition of water, the catalyst activity would not
2.404,393':
7
While~_in;most instances
the< hydrogeniiiuoride charged 4to the falkylation».
process vwill be of the commercially “anhydrous”
variety which contains several per cent of water,
under certain 'conditions 'somewhat larger
amounts of water may be present as hereinbe
fore described. This, of course, may eiîect the
location of the critical rangeV of Ytotal acidity.
Previous experienceV has shown that hydrogen
ñuoride diminishes greatly in its alkylation ac
tivity if more than from about 10% to about 15%
acting an isoparaiiîn with an oleñnsinztheefpresv
ence of a substantially anhydrous hydrogenv
iluoride catalyst, thereby Vforming a catalyst
phase containing organic diluent of higher mo
lecular weight than the alkylated isoparañîìn,
withdrawing used catalyst from and adding more
concentrated hydrogen fluoride to the alkylatingf.
step, and, by regulation of saidV catalyst .with
draWal and addition, controlling the accumula
tion of said organic diluent in the catalyst phase
Water is present. From the data presented here
it is evident that substantially larger amounts
of organic-diluent formed. duringthe alkylation
to maintain the hydrogen nuoride concentration
ofthe catalyst phase within the range ofëlfrom
.about 70 to about 85 weight percent.
reaction may be present in many cases without
an adverse effect on the catalyst activity.y
8
'i 2.; Anv alkylation processi.,-which.comprìscsn’erß4
`3. The process as defined in claim 2 further
characterized in that the `withdrawn used cata:
y
Although‘the mechanism ofthe effect of con
lyst is regenerated to separate»hydrogen'ñuoride
trolled amounts of organic diluent in the catalyst
from organic diluent and the former returned
phase is not entirely clear‘it'appears that the
to the alkylating‘step vas at least a portionof-'said
catalyst activity isl altered by the presence of the 20 more concentrated’ hydrogen Euclide.
organic material to such` an extent that unde
4. An alkylation process which comprises‘re- l
desirable- side reactions are repressed resulting
acting isobutane with a normally» gaseous olefin
in improvedquality of the alkylation-products,4
at a temperature of from about 50°F. 'to about
said improved quality being evidenced,` for eX
100° F. in the presence of a substantially anhye.
' Y ample, by the'relatively high octane number.
It 25
isnot intended, however; that the scope oi-.my
invention be limited in any way by this explana-y
tion of the effect of the organic diluent.
Eromexperimental observations I have 1 shown ‘
drous hydrogen fluoride catalyst,l thereby form
ing a catalyst phasecontaining o-rganic diluent
of higherV molecular weight vthan the alkylated
isobutane, and controlling the accumulationY of
said organic diluent. inthe lcatalystv phase;` to
that unexpectedmesultsmay be'obtained in the ï 30 maintain the titratable'acidityfoff the catalyst; `
alkylation of isoparañins: with oleñns using. a
phase within the range-of from about .'70fto about"`
hydrogen fluoride„«'cata1yst` of , relatively high vor
85 weight percent.y
ganic diluenticontent; This is contrary to previous
experience with mineral. acidialkylation catalysts,
sinceit:wouldï'ordinarily be4 expected that the
product;qualityVl would decline` continuously with
increasing*contaminationïofthel catalyst. I have
'5. An alkylation processlwhich comprises rea...
acting‘isobutane with a normally gaseous<oleñn\
at a'temperature of. from about 50° F; to about;A
100°
inthe presence of a'vsubstantially'f'anhye.î
not onflyshownthat good resultscan'be obtained ‘
withvhydrogençfluoride catalysts of relatively low
titratable> aciditiesbut Athat under-any` given set
>of processing conditions there ís yalso arelatively
criticalV range- of totalY acidity which‘must not »
i be-exceededv if products-*of optimum vquality are
to;be.obtained-.
I;claim asmyinvention:
45
1;v An alkylation-»process whichY comprises re- l
actingranfisoparamn with an‘oleñn‘in the pres
1 ence of aY substantially anhydrous hydrogen v
fluoride» catalyst', thereby. forming a 'catalyst
drous hydrogen iiuoride catalyst;;thereby forming:
a catalystfphase containingV organic diluent‘zof"
.higher molecular weight than the-alkylated‘fisoeA
«butane, withdrawing used catalystv from». and?
adding more concentrated hydrogen fluorideito
the alkylatingstep, and, by regulation ofásaid‘v
catalyst withdrawal >and addition, ,controllingtlie
accumulation of said'organicfdiluent inthe cat'- f
alystphase to maintain; the titratableracidityfof.the catalystv phase within', theA range; off' from~
about 70 to about .85.Weight percent:
6. The process as 'deiined inclaimy 5 further"
characterizedîin that the withdrawn vusedlcatat»
50 lystis regenerated to separate hydrogen‘ffluorid‘el
lecular weight .than the -alkylated ’isoparafñm andv
from'organic diluent and thelformer"returnedfto‘
n] controlling; the.>r accumulation. of: said, organic
the alkylating'step‘as at leastìa portioniofrsaidZ
y phase;.containingf~~organic diluent of higher mo
" diluent in the. catalystiphase to maintain the
î hydrogen ñuoride.- concentration ofgthe catalyst
l phasefwithinV the range of'fromeabout 703to aboutl ßârweightg'percent.
'
more = concentrated hydrogen fluoride;
HARRISON C'."
`
.
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