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Патент USA US2411437

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Nov. 19, l1946.
G. à. LAKE
2,411,437 i
RECOVERY 0F AQUEOUS AZEOTROPE FORMER IN OZEOTROPIC
DISTILLATION OF HYDROCARBONS
Filed Oct. 18, 1941
2 Sheets-Sheet 2
Y
V
o/snL/.maN
„ze-¿mane
meme? mvo
scr/.VENT
Eme/:mow
f
HZEOÍWE
‘ FORMER
H
'Genga E fahr,
>
INVENTOR
Patented Nov. 19, 1946
'
2,411,437`
2,411,437
. RECOVERY OF AQUEOUS AZEOTROPE
FORMER IN AZEOTROPIC DISTILLA
TION OF HYDROCARBON S
George R. Lake, Long Beach Calif., assignor to
Union Oil Company of California, Los Angeles,
Calif., a corporation of California
Application October 18, 1941, Serial No. 415,568
8 Claims. (Cl. 202-42)
l
.
2
.
with water since in many cases, the azeotrope
tropic distillation to prepare pure hydrocarbons
former has a preferential solubility in the hydro
carbons as compared with the solubility in the
from complex petroleum fractions'which are difii
water. «The result is that the hydrocarbons must
cult to separate by ordinary fractional distillation
due to the small differences in boiling points of Si be, washed with an excessively large amount of
the hydrocarbons contained in the petroleum
water in order to remove the last traces of the `
azeotrope former so that the hydrocarbons may
fraction. The invention is particularly directed
to an improved process for separating `the hydro
be utilized and the azeotrope former recoveredV
without sustaining a substantial loss of this more
carbons and the azeotrope former that are con
tained in the azeotropic distillate produced by the
valuable material. To illustrate, it has been found ‘
This invention relates to a process of azeo
azeotropic distillation.
that methyl ethyl ketone containing'water, i. e.,
The process of separating one hydrocarbon
component from another hydrocarbon component
about 10% by volume, is very efficient as an azeo-v
trope former to effect the separation of non-aro
Yof substantially the same boiling point contained ,
matic hydrocarbons from a hydrocarbon fraction 1
in a complex hydrocarbon fraction by azeotropic l. containing toluene. y Yet‘the use of this azeotrope
former offers the serious difficulty of recovering
distillationY is Well known. This process consists
the methyl ethyl ketone from the azeotropic dis
in distilling the hydrocarbon fraction in the pres
tillate. While the separation of` the methyl ethyl
ence of an extraneous substance which has a pref
ketone may be accomplished by washing with
erential afllnity for one of the components con
water, this has required about ñve or six volumes
tained in the complex hydrocarbon fraction, thus
of water for each volume of azeotropic distillate.
causing a disturbance of the vapor pressure equi
Furthermore, in order to recover' the methyl ethy1
librium that formerly existed in the fraction in
‘ ketone from the veiy dilute wash solution, it is
such manner that the partial vapor pressure or l
fugacity of at least one component in the fraction
necessary to heat an excessively large volume of
is changed sumciently to permit its separation by
dilute methyl ethyl ketone.
_
separation of the azeotrope former containing
relatively more paraliinic hydrocarbons together
water `as a constituent from the hydrocarbons
contained in the vazeotropic .distillate and it is a `
with the extraneous substance leaving as undis
tilledbottoms the relatively less parafl‘lnic hydro
`
It is thus an object of my invention to effect a
controlled fractional distillation. In such proc
esses, the distillation effects the separation of the
30 particular object to effect the aforesaid separa
carbons which may or may not contain a portion
of the extraneous substance. In the present de
scription of my invention, the aforesaid type of
fractional distillation will be referred to as azeo
tropic distillation, the extraneous substance `or
substances which are added to the complex hydro
carbon fraction to effect the aforementioned
change will be referred to as azeotrope formers
and the overhead from the azeotropic distillation
. will be referred to as the azeotropic distillate.
tion in an efficient and economical manner.
Itis a further object of my invention to effect
the separation of the aqueous azeotrope former
from` the'azeotropic distillate by ñrst removing
. the Water contained in the azeotropic distillate
' and then subjecting the dried‘azeotropic distillate
to fractional distillation to remove the azeotrope
former from the hydrocarbons. A further objectÄ
is to effect the fractional distillation of the dried
azeotropic distillate under temperature and pres
>One of` the main diiîiculties in the azeotropic
sure conditions which are different than those of
distillation process is in the separation or recovery ‘
the azeotropic distillation resulting in the produc
of -the azeotrope former from the hydrocarbons
contained in the azeotrope distillate. One of the f
tion of the azeotropic distillate.'
_ methods proposed for this purpose resides in
washing the azeotropic distillate with water which
l is adapted to dissolve the azeotrope former from
the azeotropic distillate and thus be separated
from the hydrocarbons by settling and stratifica
V
,
I have discovered that if the water contained in
1an .azeotropic distillate which is produced by dis
tilling a complex hydrocarbon fraction in the
presence of an aqueous azeotrope former is re
moved from the azeotropic distillate, the latter
may then be fractionally distilled `and the re
tion. The solution of azeotrope former and water 50 maining non-aqueous azeotrope former may be »
effectively separated from the hydrocarbons,
may be distilled to separate the azeotrope former
whereas if the fractional distillation-is carried
from the water.
l
out without removing the aqueous portion of the
However, difllculty has been experienced to sep
azeotrope former, an azeotrope consisting of the
arate the azeotrope former substantially com
aqueous azeotrope former and hydrocarbons will
pletely from the azeotropic distillate by washing
I 2,411,437
4
be distilled inthe same mannerand composition _
be removed by settling, centrifuging >or dilterlng
as the azeotropic distillate was removed in the
the chilled mixture.`
initial azeotropic" distillation. However, by first
.
dehydra'ting the azeotropic distillate, the compo
sitiòn of the remaining azeotropic distillate is
' modified suñlciently with respect to the partial
,
'
»
In general, the passage of the azeotropic'distil
late through the dehydrating agent is continued
until the dehydrating agent is saturated with
water and is no longer ’effective for removing fur
vapor pressure of the constituents therein so that
subsequent fractional distillation will prevent an
azeotrope from distilling over and thus a separa
tion of the azeotrope former from the hydrocar 10
is regenerated.
bons may be accomplished.
regeneration is accomplished by blowing a heat
'
.
-
In other words, it has been found that; certain
' compounds are very veiiicient azeotrope'formers
ther quantities of the ' water, whereupon the
stream of azeotropic distillate is diverted toa
fresh drier and the saturated dehydrating agent
In the case of solid absorbents,
ing gas, such as steam, air or inert gas through
_the drier containing -the dehydrating agent until
for the vseparation of“ hydrocarbons when em
all of the water has been distilled from the de
ployed in the 'absence of water, whereas other 15' hydrating agent. In the case "of the normally
. compounds are very eñicient only in the presence
liquid absorbent, regeneration maybe similarly
-of water to effect the desired separation and when
employed in the absence of water merely distill
accomplished or the saturated dehydrating agent
may be fractionally distilled at a temperature>
from'the hydrocarbon mixture without taking, » above the boiling point of water asis well known
any of the hydrocarbon components overhead. 20 by those skilled in the art. Where solid dehy
Hence, when an azeotropic distillate which is pro
drating agents are employed which form solu
duced by distilling a complex hydrocarbon frac
tions in water, the separated aqueous solution '
tion in the presence of such compound and water
may also be subjected to distillation to drive of!
_ is first dehydrated, subsequent distillation under
the'water contained in the solution.
controlled conditions of the dehydrated azeo
The dehydrated azeotropic distillate consisting `
tropic distillate results in the distillation of the 25 of the non-aromatic hydrocarbons and the azeo
azeotrope former without removing overhead any` ‘ trope former is next subjected to fractionation in
of the> hydrocarbons in the same manner -as
order to separate the hydrocarbon from the azeo
when the distillation of the initial 'hydrocarbon
trope former. Fractionation may be accom
fraction is’effected in the presence of the’azeo
plished either at atmospheric, superatmospheric
trope former. and in absence of water.
/
or under a vacuum but is preferably carried un
‘_Dehydration-of the azeotropicA distillate is 'ac
der subatmospheric conditions since these condi
tions result in effectively removing as an over
head product substantially all of the azeotrope
former as a fraction substantially free> from hy--
complished by merely contacting the azeotropic
distillate with a dehydrating agent which has a
preferential4 affinity for Water. Preferably this is
accomplished by passing the azeotropic distillate
through a bed of solid absorbent material which . .
is adapted to absorb the water in preference to
the 'organic materials contained in the azeotropic
distillate. Solid materials adapted to absorb the 40
water‘from the azeotropic distillate include acti-î
-vated clays, activated carbons, Activated Alu
mina, activated silica, cotton, _also unactivated
clays, carbons, aluminum, silica, etc.
j
drocarbons. The overhead, azeotrope formerfif
relatively free from hydrocarbons may be mixed-
with the proper quantity of water and returned
to the azeotropic distillation step. In the event
the thus separated azeotrope former contains a
substantial portion of the hydrocarbons, this mix
ture may be' condensed and then subjected to ex
traction with a selective solvent adapted to dis
„
solve one of the components, either the azeotrope
Another method which lmay be employed for 45 former or. the hydrocarbons but not substantial
quantities of the other component as will be de
tillate includes -theuse of solid water soluble com
scribed hereinafter.
pounds such` as sodium chloride, calcium oxide
- Other objects, features and advantages of my '
and chloride, sodium and .potassium carbonates;
invention will be apparent to those skilled in the
s sulfates and hydroxides and metallic salts of 50 art from the following description of the inven
pyrosulfuric and pyrophosphoric acids such as the
tion as taken from the accompanying drawings.
pyrosulfates and pyrophosphates of potassium,
In the drawings, Figure 1 represents a diagram
sodium, zinc,- calcium, mercury, silver, copper,
matic arrangement of apparatus for carrying out
etc.-« When using these dehydrating agents, the
my invention and Figure 2 represents a simplified
solid as it absorbsthe moisture lfrom the azeo 55 flow diagram showing the important process steps»
» separating the watel` from the azeotropic dis
tropic distillate'forms a solution of the dehydrat-` "
of the
' ing `agent and water 'which during the process
of passing the azeotropic distillate through the
solid compounds, separates -from the remaining
invention.
.
.
'
-
'
In the following example, the invention will be
described as applied to the separation of toluene
, from ahydrocarbon fraction employing methyl
i» solid compound and thus may lbe removed as a, 60 ethyl ketone containing about 10% by volume of
bottom layer from the drier.
water as the azeotrope former and clay as the`
Also,- normally liquid materialsïmay be em
dehydrating agent.
Y ployed as dehydrating agents for separating the
However, it will be observed '
that this example is not to be tal-:en as limiting
water from the azeotropic distillate. Liquids
my invention since the process is applicable to
which may be employed for this purpose include 65 separate other components from complex sub
glycerine, polyglycols such as mono-, di-, tri
ethylene and other glycols, sulfuric acid, etc. De
stances employing other azeotrope farmers con
taining water under conditions adapted to eil‘ect
the desired separation and other dehydrating
hydration with these materials may be accom
plished by simply .contacting the azeotropic dis
Á tillat» or bubbling the vaporized azeotropic dis
K tillate through a layer of the dehydrating liquid.
Dehydration of the azeotropic distillate may
also be accomplished by chilling the distillate to a temperature sulliciently lov.r to crystallize the
agents.
70
'
«
_
"
‘
In Figure 1, the hydrocarbon feed to be re
solved into its _component parts preferably one
having a narrow boiling range, not more than 50°
F., such as for example', a hydrocarbon fraction
having a boiling range of about 200 to 240° F.
aqueous portion of the distillate which may then 75 and consisting of substantially 45% by volume
2,411,437
6
of toluene, 6% by volume of oleñns and the re
mainder parailln and naphthene hydrocarbons
when allowed to settle into an upper phase _com
prising the b_ulk or the azeotropic distillate and
consisting of substantially all ci the hydrocar
bons and most‘ of the methyl ethyl ketone with
obtained by fractionation of a catalytically re
formed gasoline, is taken from tank I0 via line
II and is pumped by pump I2 through line I4 fil some water and a lower phase consisting of sub- _
controlled by valve I5 into line I6. Azeotrope
stantially all of the water containing the re
former, such as methyl ethyl ketone, containing
mainder of methyl ethyl ketone. In such case.
it is preferable to pass the cooled azeotropic con
about 10% water,` is takenfrom tank I1 via line
I8 controlled by valve I9 and is pumped by pump
densate from condenser 28 through lines 29 and
20 through lines 2l and 22 and valve 23 into line 10 3| controlled by valve 3Ia into a separator 32
IB where it is mixed with the hydrocarbon feed
where the mixture is allowed to stratlfy into the
two layers. The lower layer is withdrawn via
from tank I0. The mixture of hydrocarbon feed
and azeotrope former in the ratio of approxi
line 34 and may be passed by pump 32a via line
33 controlled byvalveßäa to .a recovery system
mately two parts of the azeotrope former and
one part of hydrocarbon feed in the example
for the recovery of the methyl ethyl ketone, as
herein given, is passed into fractionating column
will- be describedihereinafter. Preferably, it is
passed into line 22 where it may' be mixed with
2d where the mixture is subjected to fractiona
methyl ethyl ketone introduced into line 22 as
tion, heat being supplied by closed steam coil
25. If desired, the azeotrope former may be in
will be described hereinafter in such proportions
troduced directly into the fractionating column 20 as to 'produce an azeotropeiormer containing an
optimum amount of water which mixture may
at any other point as near the top of the column
then be recycled to the azeotropic distillate. The
in which case it will act in part as reflux for
upper layer is withdrawn via line 35 and passed
the fractionation or reñux may lœ obtained by
via line 30 to the methyl ethyl ketone recovery
cooling coil 25a. In the fractionating column,
the distillation is’controlled so as to distill over
` head an azeotrope consisting of the paraffin, ole
system.
i
The bottoms in the fractionating column 2d
ñn and naphthene hydrocarbons together with
substantially all of the methyl ethyl ketone andv
water. In the example herein given, this is ac#
consisting of the aromatic fraction or toluene are
compound such as its Iboiling point.
The type of distillation to be used depends
somewhat upon the quantity of the azeotrope
event it is desired to recover the aromatic hy
withdrawn via line 38 controlled by valve 3l and
are pumped by pump 38 through line 39. If the
complished at an overhead temperature of ap 30 hydrocarbon feed to the azeotropic distillation
has been carefully fractionated to produce a frac
proximately i60-170° F. and at atmospheric pres
tion free from aromatic hydrocarbons other than
sure. If desired, the azeotropic distillation may
toluene and if the azeotropic distillation has been
' be carried out either at atmospheric or super
atmospheric pressure or under a vacuum. Other i
carried out under such conditions as to remove
all of the non-aromatic hydrocarbons and
azeotrope formers containing water which are
azeotrope former, the bottoms from the frac- '
effective for separating the relatively non-aro
tionating column may be passed directly via lines
matic hydrocarbons from the relatively aromatic
hydrocarbons include alcohols such as ethyl, nor
36, 39,740 controlled by valve 4I, lines 52, 43 con
trolled by valve 44 and line »l5 into storage tank
mal and isopropyl, primary, secondary and ter
tiary butyl alcohols, other ketones such as diethyl 40 46. However, in the event the charging stock
has not been carefully fractionated to remove
ketone and methyl isobutyl ketone, dioxane, etc.
The optimum amount of water to' be employed
aromatic hydrocarbons heavier than toluene,
with these azeotrope Íormers for eillcient opera
such as xylene, etc., the bottoms in the fraction
ating column 24 will contain all or substantial
tion will vary from 5 to 25% by volume, depend
ing. upon the characteristics of the particular ,5. m. amounts of such aromatic hydrocarbons. In the
drocarbon mixture per se, it is passed directly to
tank 46 as described above. However, if it is de
sìred to separate the toluene from the :remain
former used. I` may distill over any proportion
of the petroleum fraction to be subjected to azeo 50 ing aromatic hydrocarbons, the bottoms are
tropic distillation that I desire by adjusting the
passed via lines 36, 39, 40. 42 into line 41 con
quantity of azeotrope former. Thus. by employ
trolled by valve 48 from which it passes through
ing a relatively small proportion of the azeotrope
heater 49 and line 50 into fractlonating column
former, it is possible to distill overhead a portion
6I where the mixture is fractionated to remove
of 'the relatively non-aromatic hydrocarbons and 55 the toluene as an overhead product aided by heat
leave a portion as bottoms with the relatively
from the heater 52. The vaporized toluene is re
aromatic hydrocarbons, or by employing a rela
` moved from the top of the Iractlonatlng column
tively larger amount of the azeotrope former, it
El via line 53, condensed in condenser 54 and
is possible to distill all of the relatively non-aro
passed via line 65 into collecting tank 56. The
matic hydrocarbons and a portion'of the rela 60 condensate may be withdrawn from the oollect- ‘
tively aromatic hydrocarbons, leaving relatively
ing tank by pump 51 and passed into line 58. If
aromatic hydrocarbons as still bottoms.
desired, part of the condensate may be cycled via
The above overhead mixture is removed'frorn
line 59 controlled by valve 80 to the fractionat
the iractionating column via line 26, controlled
lng column "5I to serve as redux for the fractiona
by valve 21, condensed in condenser 28 and passed 05 tion. The remaining portionis passed via >line
via line 29 into line 3b controlled by valve 30a to
Si controlled by valve 62 through line 46 into
the methyl ethyl ketone-water 'recovery system,
storage tank 46. The bottoms from the frac
as will be described hereinafter. In some cases,
tionating column, consisting of xylene or a mix
depending upon the hydrocarbon iîeed and the
ture of xylene and higher boiling aromatic 'hy
character and composition of4 the azeotrope 70 drocarbons, is withdrawnvia line 63 controlled by
former, the azeotropic distillate obtained in line
valve Stand pumped by pump 65 and line B6V
26 will separate into two‘phases when properly
into storage tank B1.
cooled. In the case ofithe example herein de«
In4 the event the bottoms fraction from the
scribed, cooling of the azeotropic distillate to
fractionating column 25 .contains a portion of
about 50,-70° F., the condensate will-separate 75 the azeotropeiormer, this may be removed by
2,411,491
passing the bottom fractionv via lines 36, 39 and
68 controlled by valve 69 through heater 10 and
line 1| into fractionating column 12 provided
' a temperature of 75° F. and under an absolute
pressure of 100 millimeters- of mercury. The
methyl ethyl ketone vapors may be passed via
valve |00 into line -22 where it is mixed with the
optimum amount of water such as obtained inline 34 and the mixture is passed via line I6 to
`with a heater `13 and reflux cooling coil 14 where
theazeotrope former may be fractionated and
-removed via line 15, condensed in condenser 16
and passed via line 11 into collecting tank 18 from
the azeotropic distillation in fractionating co1
which _it may b'e returned to the fractionating - umn 24. When the overhead from the fraction
column 24 by pump 19 and line 80 Ycontrolled
_ating column |00 contains non-aromatic hydro
Aby valve 9| and lines 22 and IB. The bottoms lo carbons and it is desired to separate them, the
from the fractionating column 12 may be passed
overhead may be passed via line i0| _controlled
via line 82 controlled by valve 83 into line 42
by valve |02, condensed in condenser |03 and
from which it may be -‘passed by pump 84 either
passed via line |04 into the bottom of an ex
directly to the storage tank 46 or to fractionat
tractor |05 which is provided with packing ma
ing column 5| in accordance with the’above dis
terial, such as broken tile |06, where the mix
closure.
ture is ‘countercurrently contacted with a selec
The toluene or the mixture of toluene and
tive solvent adapted to extract the methyl ethyl
higher boiling aromatic hydrocarbons obtained
ketone from the mixture. 'I‘he selective solvent
in tank 46 and the higher boiling aromatic hy
is obtained from tank |01 and passed via line
drocarbons obtained in tank 61 may be treated 20 |08 controlled by valve |09 and ypumped by pumpi »
with clay which may be accomplished at a tem
H0 into the extractor |05. As selective solvents
perature of about 230° F. employing l to 5 pounds
adapted for the purpose, tetra ethylene glycol is
of vclay per barrel of the hydrocarbon fraction.
particularly suitable when used in about two
If ldesired, the clay treatment may precede the
volumes to one of the. hydrocarbon-methyl ethyl
fractionation in fractionating column 5| in which
ketone mixture at about atmospheric tempera- l
_ case the 'fractionation in 5| may serve either to
ture.
rerun the clay treated stock and/or to fractionate
Besides tetra-ethylene glycol mentionedabove,
the high boiling aromatic hydrocarbons from the
toluene". In place of clay treatment, the aro
selective solvents which I have found suitable '
to effect the extraction of azeotrope formers from
v matic fraction may be cooled and then treated ;
azeotropic distillates include phenolic compounds
such as resorcinol, para-chlorophenol, phenol,
with 1 to 10 pounds of sulfuric acid per barrel of
the hydrocarbons followed by neutralization with
xylenol, pyrogallol, pyrocatechol and cresylic acid,
clay or caustic alkali. The acid treatment serves
to remove small traces of undesirable unsaturated
v
polyhydric alcohols such as di-, tri-. tetra- and
hydrocarbons which may be detrimental in color
stability'and nitration of the toluene.
In order to recover the azeotrope former from
the azeotropic distillate, the latter is passed into
the bottom oi' either of the driers 85 through linesY
86 and valves 81 which are ypacked with a'clay 40
adapted to remove the water contained inthe dis
tillate when passed upwardly in contact with the
clay. If desired, the dehydration may be effected
while the distillate is in the vapor phase and in
hexaethylene glycols and dipropylene glycol,`
amines such as mono-, di- and tri-ethanolamine,
2-methyl propanol amine, diethylene triamine,
trlethylene te‘tramine, tetra-ethylene pentamine.
diethylene diamine, tri-ethylene triamine, di
phenylamine, xylidine, aniline, ,ortho phenylene
diamine, alpha naphthol amine and phenyl hy
drazine, fatty acids such as acetic, propionic and
form'ic acids. aliphatic alcohols such as methyl.
ethyl, isopropyl. tertiary butyl and normal propyl
alcohols, ketones such as methyl ethyl ketone
this respect„the >condenser 28 may be deleted or .i and acetone, cyclic lketones such as cyclohexan- "
operated as a temperature regulator to adjust
one, alkyl ethers of polyglycols such as mono
the temperature of the distillate vaporto the
ethyl ether of diethylene glycol and ethyl ether A
proper level for optimum operation in the drier.
Preferably,l ‘the drying is vaccomplished by per
colating upwardly a condensate of the azeotropic
distillate through the clay.
The dehydrated azeotropic distillate is withdrawn from the driers 85 through valves l88~and
I» line 89. Preferably the driers are operated alter- l
nately, one being employed until 'the dehydrat
ing agent is saturated with water so that it is no
. llonger eifective to dehydrate the distillate, after _
of ethylene glycol, heterocyclic compounds s‘uch
, as furfuryl alcohols. tetrahydro furfuryl alcohol.
dioxane. morpholine, plperidine and thiophene, '
nitroparaflins such as nltromethane, nitroethane
and nitropropane. In addition to the above. aro
matic hydrocarbon solvents may be employed to
` effect the desired separation since the azeotrope
formers have a‘ greater ailìnity for these hydro-`
carbons than they have for the relatively non
aromatic hydrocarbons contained in the azeo
«which the distillate stream is diverted to the
tropic
distillate. Aromatic` hydrocarbon solvents
other drier and the saturated dehydrating agent ’ - useful forA the purpose include benzene.
toluene,
is regenerated.¿ Regeneration is accomplished 60
xylenes, étc. ' Of the above selective solvents.- I
= by blowing a heated gas. such as steam, air or
have found the polyhydric alcohols such as di-.
inert-gas through the dehydrating agent which
tri- and tetra ethylene glycolsA amines such
may be introduced via lines 90 controlled by
as mono- and tri-ethanolamine and dii-ethylene
valves 9|. The regenerating gases `and water sep
triamine, and also'resorclnol and nitromethane
arated from the dehydrating agent _in the ti'orm
to be particularly eiiicient for extracting such
of steam is removed from the driers 85 via‘lines
azeotrope‘formers as methyl-ethyl ketone and
82 controlled by valves 93.
methanol from azeotropic distillates containing
The‘dehydrated distillate passing through line
non-aromatic hydrocarbons having a boiling
80 is heated in heater 94 and passed via line 95
range of 2,00 to 240° F.
, '
into the Vfractionating- column 96 which is pro 70 Instead of employing a selective solvent for the
vided with heater 91 and reflux -coolingV coil 98
azeotrope former in order to separate it from the
' where the methyl ethyl ketone isvdistilled from
hydrocarbons,- I may employ a solvent which is
thehun-aromatic hydrocarbons and withdrawn
from the fractionating column via line 98.. Frac
u selective for the hydrocarbons and thus separate
a solution of the solvent and hydrocarbons from
tionation in“column 90 is preferably carried at 75 the azeotrope former. Solventsv adapted to ac
2,411,437
ll0
complish this purpose include highly parailinic
chemically similar hydrocarbon components~ dis
hydrocarbons of high boiling point such as solvent
reñned lubricating oill fractions which have a
-tilled therefrom which comprises distìlling said
complex hydrocarbon fraction in the presence of
greater affinity for the non-aromatic hydrocar
bons than for azeotrope former. Also, low melt
ing paraflin waxes and other paraiiin hydrocar
a. suiiicient amount of an azeotrope` former and
water to produce an azeotropic distillate consist
ing of at least one class of the chemically similar
components contained in said complex hydrocar
bons may be used for this purpose.
The non-aromatic hydrocarbons, if relatively
, free of methyl ethyl ketone are withdrawn from
bon fraction together with said azeotrope former
and Water, thereby leaving at least one class of
chemically similar components diiîerent from said
chemically similar components contained in said
azeotropic distillate -contained in said complex'
hydrocarbon fraction in the residue, the steps of
dehydrating said azeotropic distillate with a de
hydrating agent, that bodily removes water sepa
rating the remaining-azeotropic distillate from
the dehydrating agent and water and fraction
the top of the extractor |05 via line l|-| controlled
by valve H2 and are pumped by pump H4 into
storage tank H5, Non-aromatic hydrocarbons
separated in fractionating column 96 are with
drawn as bottoms via line H6 controlled by valve
lli and are passed by pump | I8 into storage tank
I l5. The solution of selective solvent and methyl
ethyl ketone is withdrawn vla line l |9 controlled
ally distilling said dehydrated azeotropic distillate
by valve §20 and pumped by pump |2| through
to separate the azeotrope former from hydro
heater |22 into fractionating column |23 provided
with heater |26 Where the mixture is fractionated 20 carbone.
to separate the methyl ethyl ketone as an over
head vapor which may be passed via line |25 and
valve |26 through lines 2|, 22 and l5 into the
fractionating column 2li or the overhead may be
passed via line I2? controlled by valve |23, con
densed in condenser iig and collected in collect
2. In a process for the treatment .of a complex
hydrocarbon fraction to separate chemically sim
ilar hydrocarbon components therefrom from
other hydrocarbon components contained there
in which ordinarily distill from the hydrocarbon
fraction in the same temperature range as said
ing tank |36. As indicated above, the lower layer
in separator 32 passing through line 33 may also
be passed into the fractionatlng column |23 for,
chemically similar hydrocarbon components dis
tilled therefrom which comprises distilling said
may be passed via line E32 controlled by valve
components contained in said complex hydro
carbon fraction together with said :azeotrope
complex hydrocarbon fraction in the presence of
the recovery of the azeotrope former. The con 30 a suñcient amount of an azeotrope former and
water to produce an azeotropic distillate consist
densate is Withdrawn from the bottom of the
ing of at least one class of the chemically similar4
collecting tank by pump |3| and ‘part thereof
|33 to fractionating column `|23 to serve as reñ‘ux
for the fractionation. The remaining portion of
the condensate is passed via line ist controlled
by valve §35 into storage tank il. The selective
solvent is withdrawn from the bottom of the
fractionating column |23 via line |36 controlled
by valve I3? and is pumped by pump §38 through
cooler i3d and line iëlû to storage tank lill.
As disclosed above, the methyl ethyl ketone dis
tilled as an overhead vapor in fractionating col
umns 96 and |23 may be passed to the azeotropic
distillation in iractionating column 2d to serve
as azeotrope former for the distillation. How
ever, since the azeotropic distillation in 24 is pref
erably carried out in the presence of a mixture'
of 90% methyl ethyl ketone and 10% water, the
overhead >vapor from fractionatlng columns 96
and £23 will be relatively free of water and thus
this overhead vapor must be adjusted to the
. former and water, thereby leaving at least one
class of chemically similar components different
from said chemically similar components con
tained in said azeotropic distillate contained in
said complex hydrocarbon fraction in the residue,
the steps of dehydrating said azeotropic distil
late with a dehydrating agent, that bodily7 removes
water separating the remaining azeotropic distil
late from the dehydrating agent and water and
fractionally distilling said dehydrated azeotropic
' distillate at a reduced pressure to separate the
azeotrope former from hydrocarbons.
3. In a process for the treatment of a complex
hydrocarbon fraction to separate it into com
ponent' parts of dissimilar characteristics which,
comprises .distilling said complex hydrocarbon
fraction in the presence of a sumcient amount of
an aqueous azeotrope former to produce an azeo
tropicvdistillate consisting of at least one of the
components contained in said complex hydrocar
tropic distillate from 24 is cooled and separated 55 bon fraction together with said azeotrope former
and Water, thereby leaving at least one of the
in separator 32 and the bottom layer consists sub
components contained in said complex hydrocar
stantially of' Water, this bottom layer may be
bon fraction in the residue, the steps of dehydrat
mixed with the overhead from fractionating col
ing said azeotropic distillate with a dehydrating
umn 9S and |23 to effect, in part, the desired ad
agent, that bodily removes water separating the
justment of water, content in the azeotrope
dehydrated azeotropic distillate from the dehy
former. Also; the water separated from driers
@E may be passed into line 22 to effect the above , dra-ting agent and water, fractionally distilling
said dehydrated azeotropic distillate to 4separate
'adjustment of water content.
the azeotrope former together with a portion of
The foregoing description of my invention ls
not to be taken as limiting my invention but only 65 hydrocarbons contained in said azeotropic distil
late from remaining hydrocarbons and extracting
as illustrative thereof since many variations may
said separated mixture with a selective solvent
be made by those skilled in the art without de
to separate said azeotrope former from said hy
parting from the scope of the following claims,
dro'carbons.
I claim:
.
4. Ina process for the treatment of a complex
1, In a process for the treatment of _a complex
hydro-carbon fraction to separate chemically sim
hydrocarbon fraction to separate chemically sim
ilar hydrocarbon components therefrom from
ilar hydrocarbon components therefrom from
other hydrocarbon components contained there
> other hydrocarbon components contained there
proper water content by addition of water.
In A =
some casesas described above, when the azeo
in which ordinarily distill from the hydrccarbonV
in Ywhich ordinarily distill from the hydrocarbon .~
fraction in the same temperature range as said 75 fraction in the same temperature range as said
Il
2,41 1,487
_
chemically similar hydrocarbon components dls- v
till therefrom, which comprises distilling said
lar components contained in said complex hydro
carbon fraction together withl said azeotrope
former and water, thereby leaving at least one
components contained in said complex hydrocar
bon fraction together with said azeotrope former
and water, thereby leaving at least one class oi
class of chemically similar components, diiIer
ent from said chemically similar components
contained in said azeotropic distillate, contained
in said complex hydrocarbon fraction, in the resi
due, the steps oi' dehydrating said azeotropic dis
chemically similar components, diiïerent from
„'said chemically 'similar components contained in
' said azeotropic distillate, contained in said com
plex hydrocarbon fraction, in the residue, the
steps oi dehydrating said azeotropic distillate with
tillate withl a solid absorbent- that bodily removes
Water separating the dehydrated azeotropic dis
a solid absorbent that bodily removes water, sepa-.
tillate from the solid absorbent and water and
rating the remaining azeotropic distillate from
fractionally distilling said dehydrated azeotropic
the solid absorbent and water and separating the
distillate to separate the azeotrope former from
y azeotrope former from hydrocarbons.
5. In a process for the treatment of a complex
l
hydrocarbon fraction to separate chemically sim
ilar hydrocarbon components therefrom from
20
chemically similar hydrocarbon components dis
till therefrom, which comprises distilling said
‘
water to produce an azeotropic distillate consist
ing of at least one- class of the chemically simi
a suiiicient amount of an azeotrope former and
water to produce an azeotropic distillate consist
ing of at least one class of the chemically similar
fraction in the same temperature range as said
12
a suiflcient amount of an azeotrope former and '
complex hydrocarbon fraction in the presence of
otherl hydrocarbon components contained therein
which ordinarily disti11 from the hydrocarbon
l
complex hydrocarbon fraction in the presence of
hydrocarbons.
6. A process according to claim 4 in which said
solid absorbent is clay.
7. A process according to claim 4 in which said
solid absorbent is carbon.
-
8. A process according to claim 4 in which said
solid absorbent is alumina.
«
‘
_
GEORGE R. LAKE.
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