Dec. 23, 1952
Q_,y ct. RAY
SEPARATION oF CYCLOPENTANQN'E
Filed sept. 2v, 194e
2,623,072
Patented Dec. 23, 1952
2,623,072
UNITED STATES PATENT OFFICE
2,623,072
SEPARATION OF CYCLOPENTANONE
Gardner C. Ray, Bartlesville, Okla., assig'nor to
Phillips Petroleum Company, a corporation of
Delaware
Application September 27, 1946, Serial No. 699,665
2 Claims. (Cl. 260-586)
l
2
cyclopentanone and about 36 volume per cent
This invention relates to a distillation process.
In one aspect this invention relates to the separa
Water. I have further discovered that cyclo
tion of a cycloalkanol, such as cyclopentanol,
pentanol and water boil simultaneously at a tem
and/or a cycloalkanone, such as cyclopentanone,
perature of 96.1° C. at a pressure of 74.8 mm. of
from water. In still another aspect this inven CD mercury to produce a distillate comprising about
43 volume per cent cyclopentanol and about 57
tlon'relates to a process for the manufacture of
an oxygenated cycloalkyl.
volume per cent Water.
Cyclopentanol and cyclopentanone are highly
Upon determining the solubility or" cyclopen
valuable organic compounds used as explosives
tanol and aof cyclopentanone in water and of
Water in cyclopentanol and in cyclopentanone
intermediates, solvents, organic synthesis inter
mediates, etc. Commercial processes involving
at 80° F., I have also found that the partial solu
bility relationships exist as shown in Table I.
their production and purification are, therefore,
desirable. In the course of the production or
TABLE I
utilization of these compounds, they are often
obtained admixed with appreciable quantities of
water, and in some cases, water-soluble, non
volatile acids or alkalis are also present.
An object of this invention is to provide a
continuous process for the recovery of cyclo
pentanol and/ or cyclopentanone from their aque
Cyclopentanone in water,
vol. percent
Water in cyclopentanone,
vol. percent
Cyclopentanol
in water, vol.
percent
Water in cy
clopentauol,
v01. percent
29.6
13,8
9.6
16. 8
20
ous solutions.
Another object of this invention is to provide
Upon cooling and condensing either the cyclo
pentanone-water azeotrope or the cyclopentanol
water azeotrope from their normal boiling tern
mixture comprising cyclopentanol, cyclopenta
peratures to 80° F., two liquid phases result, a
none and water.
25 Water-rich phase and an organic compound-rich
Still another Aobject of this invention is to
phase. A considerable concentration of cyclo
provide a process for the manufacture and purin
pentanone or cyclopentanol results from the
cation of cyclopentanone.
azeotropic distillation of somewhat dilute aque
A further object of this invention is to provide
ous solutions of either the ketone or the alcohol.
a process for the manufacture and puriñcation
If desired, the upper or organic phase of the
of cyclopentanol.
condensed azeotropic distillates may be redistilled
A still further object is to provide a process
to produce a quantity of anhydrous ketone or
for the removal of water from a solution of an
alcohol since insuñicient water is present in these
oxygenated cycloalkyl.
Other objects and advantages will become ap 35 phases to form an azeotropic mixture with all
the ketone or alcohol present.
l
parent from the accompanying description and
a method for separating the components of a
disclosure.
If quantities of non-volatile acids or bases, such
as sulfuric acid or sodium hydroxide, are present,
..
The drawing represents a diagrammatic show
ing of apparatus adapted to carry out the in
vention.
it is sometimes advantageous to introduce addi
40 tional water into the aqueous mixtures contain
.
In. ordinary distillation at atmospheric pres
sure, cyclopentanone and cyclopentanol have
normal boiling points of about 130° C. and about .
140° C., respectively. Since water has a normal
boiling point of 100° C., it would appear that
Water could be readily distilled from the alcohol
or ketone. However, I have found, much to my
surprise, that upon distilling solutions of either
these compounds in water, constant-boiling mix
ing cyclopentanol or cyclopentanone prior to
azeotropic distillation. Reducing the concentra
tion of the acid or base present in this manner
oftentimes eliminates the occurrence of undesir
able side reactions, such as the dehydration of the
alcohol, polymerization of the ketone, esteri?lca
tion of the alcohol, and the like.
In view of the above discoveries, a solution of
water and a cycloalkanol and/or a cycloalkanone,
tures are produced each of which has a normal 50 the alcohol and the ketone possessing partial ¥
I
solubility with water and preferably containing
have discovered that cyclopentanone and water
distil simultaneously at 92.6° C. at a pressurel
of 740 mm. of mercury to produce a distillate
a single ring having not more than six` carbon
boiling point slightly below that of water.
atoms permolecu1e, is separated into its com
ponents by a series of continuous azeotropic dis
having a composition of about 64 volumeper cent 65 tillation steps. Since two liquid solutions of
2,623,072
4
3
water and the organic compounds exist, that is,
is present. The aqueous phase which contains
sulfuric acid and cyclopentanol and which has
one solution in which water is the solvent and
been diluted to about a 5 to l0 per cent con
the organic compounds are the solute and the
centration of acid is passed through line lil to
other solution in which either or both of the
organic compounds are the solvent, this invention Si distillation zone I6. Water and sulfuric acid sub
stantially free from cyclopentanol are withdrawn
is equally applicable to the separation and re
from disitllation zone I6 as a bottom product
covery of the components of either solution. In
through line Il and water and cyclopentanol are
separating the components of such solutions, the
withdrawn as an overhead product through line
liquid solution is introduced into a ñrst distilla
The aqueous sulfuric acid withdrawn from
tion zone and the solvent is removed therefrom
column lil through line il may be reconcentrated
as the bottom product and substantially an azeo
by distillation and returned to reactor l for re
tropic mixture of water and the organic com- i
pound is removed therefrom as an overhead
previously
use in promoting
stated, the
the overhead
hydrationazeotropic
reaction. mix
product. The overhead product is condensed
and allowed to separate into 'two liquid phases,
ture has a’composition of about 43 volume per
cent cyclopentanol and about 57 volume per cent
water. The overhead fraction is condensed and
a solvent-rich phase and a solute-rich phase.
The solvent-rich phase is returned to the first
distillation zone and the solute-rich phase is in
separated into two liquid phases ‘by passing the
troduced into a second distillation zone and a
stream through condenser I9, line 2l into ac
compoundl are removed therefrom. This over
head fraction from the second distillation zone
through line 26 for further fractionation. The
.lower aqueous phase in settler 22 .containing
about 9.6 volume per cent cyclopentanol is re
turned to column I6 through line 23, preferably
to the feed plate of that column.
bottom product comprising the solute and an 20 cumulator 22. The upper cyclopentanol-rich
phase containing about 16.8 volume per cent
overhead product comprising substantially an
water is passed to a second distillation zone 25
azeotropic mixture of water and the organic
is also condensed and separated into two liquid
phases in the same step as the overhead from
the ñrst distillation zone. If either the solute
or the solvent Withdrawn as a bottom product
In distillation column 26 a second separation
is made between cyclopentanol and water; and
this mixture may be separated into its components 30 azeotropic mixture of cyclopentanol and water
is withdrawn overhead from column 26 through
in a third distillation step.
>line 2l andrecycled through condenser i9 to
The above data for the phase relationships and
separator 22. '.This azoetropic mixture is similar
the properties of the mixture of water, alcohol
in composition/to theazeotropic overhead mix
and ketone will vary somewhat with pressure and
alterations or changes in pressure to gain sim 35 ture 0i’ column I6 and therefore can be separated
inte two phases in a similar manner as the over
ilar results is within the scope of this invention.
head in column i6. Since insufñcient water is
As an example of the application of the knowl
present in the feed to column 25 to form an a'zeo
edge imparted by this invention, a process for
trcpic mixture with all the cyclopentanol present.
the production and purification of cyclopentanol
and cyclopentanone will be described with refer 40 cyclopentanol substantially free from water is
withdrawn as a liquid from column 26 through
ence to the drawing >accompanying this applica
lines 28 and 52 as a product of the process. The
tion. Although the azeotropic properties of cy
approximate boiling point of the cyclopentanol
clopentanol and cyclopentanone with water are
water azeotrope is about 96° C. while the boiling
especially applicable >to the processes to be de
scribed, the accompanying description should not 45 point of cyclopentanol itself is about 140° C.; thus
it is apparent that the separation between the
be construed to limit the applica-tion of this in
cyclopentanol and the azeotrope may be eifected
- vention to such a process, According to the draw
with ease in column 26.
ing, Cyclopentene and sulfuric acid together with
When cyclopentanol is not the desired product
water are introduced into hydration reactor 'l
»through lines 6 and ê, respectively. The cyclo 50 but is an intermediate product in the production
0f cyclopentanone, cyclopentanol is passed
pentene feed may be obtained from various
through line 28 to reactor 29 in which the cyclo
sources, such as petroleum refinery processes.
pentanol is converted to cyclopentanone. The
When using about 65 to about 75 per cent sul
conversion of cyclopentanol to cyclopentanone is
furic acid, appropriate reaction conditions for ef
fecting the hydration of the Cyclopentene are a 55 effected inthe presence of a catalyst, such as
nickel or brass. Since the conversion products,
temperature of about 75 to about 85° F. at at
‘ comprises a mixture ofv a ketone and an alcohol,
mospheric pressure and a residence time of about
With such conditions the conver
aside from cyclopentanone, are somewhat differ
ent >depending upon the catalyst, the purification
of the conversion effluent must be eifected ac
sion of Cyclopentene to cyclopentanol is about 50
to about 80 per centper pass. A liquid eñluent 60 cordingly. When nickel is used as the catalyst,
.the conversion is carried out at a temperature of
from reactor 'l is passed therefrom through line
about 260° C, at about atmospheric pressure.
8 and admixed with water entering line 8 through
The normally liquid portion of the conversion
line 9. Water-is added to the eilluent in order
eíiluent under certain conditions comprises ap
to hydrolyze the sulfuric acid esters and to suf
proximately the composition shown in Table 'II
ficiently dilute the acid to prevent or minimize
below.
side reactions (asalcohol dehydration) during
TABLE I1
subsequent distillation steps. The resulting aque
. 2 to 3 hours.
ous mixture is cooled (not shown) and vis then
passed to separator Il wherein a liquid organic
phase and liquid aqueous phase ar-e formed. The 70
lighter organic phase comprising polymers and
unreacted hydrocarbons, and other side reaction
products is removed from separator l-I through
line l2 and discarded, if desired. or distilled to
recover cyclopentanol if an appreciable quantity
Component:
Volume percent
Cyclopentene
_______________________ -_
5
Cyclopentano1_____V __________________ -_ 20
Cyclopentanone ______________________ _; 20
Water ______________________________ _-150
APolymers
___________________________ __
5
The conversion effluent from reactor 29 is passed
`v'therefrom through line 30 to a gas separator 3|
» 2,623,072
5
6
in which hydrogen is separated from »the liquid
eñluent. From gas separator 3l the liquid con
zone 51 through line 59 to condenser 6I and then
through line 62 «to separator or accumulator 63.
version eil‘luent is passed to a first distillation
zone 32. In distillation zone 32 the cyclopentene
The bottom product comprising cyclopentanone
substantially free from water is withdrawn
through line 58 as a product of the process. In
is separated from the conversion eñiuent as an
separator 63 an upper organic phase comprising
overhead product and is recycled «to reactor 1
through line 34 and line 6. The bottom product
'from distillation zone 32 comprisingl cyclopen
tanol, cyclopentanone, water and polymers is
cyclopentanone and about 13.8 volume per cent
water is separated from a lower aqueous phase
comprising about 29.6 volume per cent cyclopen
tanone. The upper` organic phase is returned to
distillation zone 51 through line 64 and the aque
ous phase is passed to a second «distillation column
61 through line 65. Substantially an azeotropic
mixture of cyclopentanone and water is with
passed to a second distillation zone 36 through
line 33. In distillation zone 36, substantially an
-azeotropic mixture of Water and cyclopentanol,
and water and cyclopentanone is distilled over
head while water and polymers are removed from
distillation zone 36 as a bottom product through
line 31. The overhead fraction from distillation
zone 36 passes through line 38 to condenser 39
and thence through line 4l to separator or >ac
cumulatorl 42. rEhe resulting condensate is sepa
drawn as an overhead product from distillation
zone 61 through line Á68 and is passed to con
denser 6l and separator 63 for separation into
two liquid phases as previously described. Water
is withdrawn from distillation column 61 from
rated into two liquid phases in separator 42, an
upper organic phase comprising a major propor
line 59 to keep cyclopentene from building up ln
the system.
tion of cyclopentanone and cyclopentanol and a
lesser proportion of water and a lower aqueous
In a similar manner, this invention may 'be
applied to a process for the manufacture of `cy--
phase comprising a major proportion of water
with minor proportions of cyclopentanone and
cyclopentanol. The aqueous phase is returned to
distillation zone 36, preferably to the feed plate
cyohexanol and cyclohexanone and to the separa
tion of such compounds from their aqueous solu
tions.
The following examples are offered as exem~
thereof, by means of line 43.
plary of the separation described in this appli
The upper or
ganic phase is passed from separator 42 through
cation, and should not be considered unneces
lnie 44 to a third distillation zone 46. A mixture
sarily limiting to lthis invention.
Example I
of water, -cyclopentanol and cyclopentanone is
passed
overhead
from
distillation
zone
46
The separation of cyclopentanone from a di
through line 41 and passed to condenser 39 and
lute aqueous solution by batchwise azeotropic
separator 42 to be separated into two liquid phases
distillation is illustrated by the data of Tables
as previously described. The bottom product
III and IV below:
from distillation zone 46 comprises cyclopenta
none and cyclopentanol substantially free from
TABLE lll
Charge:
water. This bottom product is passed through
60.0 cc. cyclopentanone
230 cc. distilled water
_line 48 to a fourth distillation column 49 to be
ratio: 10:1
separated into an overhead fraction comprising 40 Reflux
Column: Approximately 'J5 equivalent theoretical plates
cyclopentanone which is removed through line
53 and a bottom fraction comprising cyclopen
Vol.
Vol.
Total
tanol which is removed through line 5|. The oy
",Iätä Vâl'oof ¿g3g percent percent ketone
Cut No. fract‘ion phâse phase
zO in ketone in both
clopentanol may be recycled to reactor 29 through
c c '
c c ’
c c '
ketone
in H2O phases,
line 52, if desired. Since the boiling point of 45
cyclopentanone is about 130° C. and the boiling
16. 5
point of cyclopentanol is about 140° C. the sep
13. 5
aration of the ketone and alcohol in distilla
34. 0
’
tion -zone 49 is effected with ease.
’
When brass is used as the catalyst for the
conversion of the cyclopentanol to cyclopentanone
at about 30D-325° C. and one atmosphere pres
sure, the conversion is about 95 per cent, accom
panied by the formation of very little water, cy
clopentene, and other by-products. Although the
contamination of the cyclopentanone with other
compounds, such as cyclopentene, cyclopentanol,
etc. is small, sufficient water may be present to
warrant its removal, but in a different manner
‘
‘
phase
phase
c. c.
u. 0
spectively, thereby decreasing the number of trays
.umns.
`
25. 0
13. 5
22. 0
In some in
stances it may be desirable to return a portion
of the organic phase in separators 22 and 42 as
.auliquid reñux to the top columns I6 and 36, re
necessary in the rectification section of the col
'
TABLE IV
l
55
Accum '
,
Out No.
l
Accum.
'
|
Vlgèll‘lë’gï
përrceut
ol. per- Overhead
ketone
ketone
cent of
temp"
charge
’in the
c-ha-rge
‘o C" at
distilled azeotrope dlstuled end of cut
overhead
Overhead
92. 62
92. 62
92. 62
92. 65
9S. 4
99. 2
99. 2
Bumm
eter 'mm
lig
'
739. 6
739. 6
739. G
739. 8
739. 6
740. 3
740. 3
than previously described with regard to the
conversion using a nickel catalyst. When a brass
catalyst is used, the conversion effluent is passed
By redistilling the combined ketone phases
from cuts 1 »to 4, `cyclopentanone-water azeotrope
from line 30 through line 56 to a first distillation
is obtained as an overhead fraction, and sub
zone 51 in which an overhead product comprising 70 stantially pure cyclopentanone is recovered as a
cyclopentanone and water along with traces of
kettle residue.
cyclopentene and a bottom product comprising
Encample II
cyclopentanone with traces of cyclopentanol and
polymers are formed and withdrawn therefrom.
The overhead product is passed from distillation
The separation of cyclopentanol from a dilute
aqueous solution by batchwise azeotropic distil
' 24,623,072
7
'8
.letìonis iilustratedby .the `data 0f Tables V and
VI below;
-
Watehrisli phase, returning said. `~water«rich
nhese'to said ñrst distillation zone. passing said
.
'
cyclopentansne-rißh phase t0 a second distille
.tion Zone.. removing. an Overhead product com
prising substantially an azeotropic mixture of
cyclopentanone and Water from said second dis
tillation zone and passing same to the aforesaid
condensation step, and removing a bottom prod
uct. comprising cyclopentanone from said sec
TABLE V
Charge:
27.0 CC. Dur@ QYCIODGHhinQl; 273 cc. distilled water (9.0 ucl. rer
Qcent cyelopentanol)
Column: 36 plates
ë
î
e
É
`
y
ï
|
Vol.
i
Vol.
A
y
Total
T-otal
our ivëi‘lfäie ‘rili'oor l Ãiâàt‘âi ârälzöslt'pîfcânlt slsgggâ leghe
'
-
-
,
‘
j
V2
1n
aco
o
1n
10 ond distillation zone as a product of the process.
,
No' i m mit’ phi-15e’ I’ÈS'ÉL' [alcohol in H2O phases, phases,
l ‘c‘
1.i
„t' ..
2
I
ß' c'
._ l
i
L'
16.5 |
._
13.0 1l..
n.0 |
24.15 i
13.5` l
4`
37.0 |
37.0
5
20.0*
20.01 ______
12.5 I
10.0 l
-
phase
c. c.
_c. c.
15.8
, l
2.5 i
l
_.
`
'i
, phase
......
..... _.
_
Acculn.
Water-rich solution containing the same, which
comprises introducing- such a liquid solution into
v13.8
9.3
a ñrst distillation zone, removing from said lfirst
37.0
distillation zone a bottom product comprising
Water and an overhead product comprising sub
stantially an azeotropic mixture of cyclopen
tanone with Water,A condensing said overhead
20.0
TABLE YI
.
2. A rcontinuous process for the separation and
recovery of dissolved cyclopentanone from a
Acleum,
v0 .per-
A _
product `from said ñrst distillation zone to form
a liquid cyclopentanone-rich phase and a liquid
âïì‘êt: Éîêââ Bamm. vyegggç- gçgglgï was? t
water-rich phase, returning said water-rich
cent of temp. at
phase to said ñrst distillation zone, passing said
cyclopentanone-rich phase to a second distilla
tion zone,¿removing an overhead product c_om
Cut No.
eter.
alcohol rêcgv'cred alccêlìilol
I
I
`
1 _______ _.I
9. S
96, 08
T48
51
41
18. 0
22. 1
Q6. 12
99. 40
747. 5
747. 0
93
99
75
83
l(
cîlltd‘?ë mm. H` recovered
"
'
in azléotrdpe
phase
overhead alcohol
prising substantially an azeotropic mixture of
2
3
i.-
5. A
_
34.5
99.35
745.()
‘J9
S3 .
42. 2
Q9. 35
74.4.
99
83
Residue: 163 cc.=53.5 vol, percent of charge.
Distillation loss: 4.3 vol. percent of charge.
By redistilling the combined alcohol phases
from cuts 1 -to 3, cyclopentanol-.Water azeotrope
is obtained as an overhead fraction, and substan
cyclopentanone and water from said second dis
tillation zone. and passing same. to the aforesaid
condensation step, and removing a bottom prod
uct comprising cyclopentanone from said second
distillation zone as a product of the process.
GARDNER. C. RAY.
REFERENCES CITED
The following references are of record in the
ille of this patent.:
tially pure cyclopentanol is recovered as a kettle
residue.
UNITED STATES PATENTS
Various modifications and alterations of this
Number
Name»
Date
invention may become apparent to those skilled 40 1,394,232
Stevens ______ ____ __ Oct. 18, 1921
in 'the art for ‘the separation and purification of
1,911,832
Lewis ____________ __, May 30,- 1933
cyclopentanol and cyclopentanone without de
2,290,636.
Deanesly __ ______ __ July 21, 1942
parting from the scope of this invention.
2,368,497
Shipley et al ______ __ Jan. 30, 1945
I claim:
2,414,646
Hopp _____.____._____ Jan. 21, 1947
1. In a process for the manufacture of cyclo
2,417,635
Davis ___ _________ __ Mar. 18, 1947
pentanone by the dehydrogenation of cyclopen
' tanol under conditions such that water is formed
as a by-product and forms a Water-rich solu
f tion with the cyclopentanone product, the meth
¿od for purifying the cyclopentanone product 50
-which comprises introducing such a liquid solu
tion into a nrst distillation zone, removing from
2,439,513,
Hamblet et al _____ __ Apr.. 13, 1948
FOREIGN PATENTS.
Number
315,012
Country
Date '
Germany _____ __.___ Oct. 23, 1919
OTHER REFERENCES
Randall et al., “Eractionation- of partially- mls
cihlel liquids,” 31 Industrial and Engineering
prising Water and an overhead product compris
ing substantially an azeotropic mixture of cyclo 55 Chemistry, 1181-1186 (September 1939).
Othmer, “Partial pressure processes,” 33> In
pentanone and Water, condensing said overhead
dustrial and Engineering Chemistry, 11106-1112
product from said ñrst distillation zone to form
(September 1941).
a liquid cyclopentanone-rich phase and a liquid
said ñrst» distillation zone a bottom product com