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Nov. 19, 1946.
F, E, FREY
2,411,256
CONVERSION 0F HYDRocARBoNs
Film> Novl 13, 1942
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RKI
BY
gw?"
ATToRNEx/s
Patented Nov. 19,r ‘1946
y 2,411,256
?UNITED STATES PATENT oFFlc
@2,411,256
~
~
»CONVERSION 0F HYDROCARBON S
Frederick E. Frey, Bartlesville, Okla., assignor to
Phillips Petroleum Com pany, a corporation of
Delaware
Application November 13, 1942, SerialNo. 465,495
2 Claims.
1
(Cl. 260-680)
.
2
Thisinvention relates to the production 'lof di
' olefin hydrocarbons -from more saturated hydro
be carried out in the presence or absence of cat
alysts.`
tion of low-boiling `diole?ins,particularly butadi- '
` `Acetylene can be ~produced by pyrolysis of rela
one and pentadienes from paralfln and oleñn hy
tively more saturated hydrocarbons at partou
larly high temperatures with a yield of. 5 to l0
Weight per cent and higher of the total products.
At the time and temperature levels suited for
,effecting juncture with ethylene to produce bu
_dijocarbons.I
Butadiene and related dioleñn hydrocarbons
They have been produced in a -
number of Ways, including vapor-phase cracking
of oils, Dyrolysis of organic compounds, dehydra
tion of lower aliphatic alcohols and of butylene
glycol, elimination of hydrogen halide from di
halides of paraffin hydrocarbons, dehydrogena- ,
` tadiene, there is a strong tendency for acetylene
to undergo auto-polymerization. This reaction
takes place much more rapidly than the auto'
polymerization of ethylene at the ‘same time
tion` of olefin hydrocarbons, vand other :more or
temperature-partialpressure conditions. Bysup
„less involved chemical .processes such as the syn- '
thesis of butadiene from phenol and the co~reac~
tion ofA .acetylene and ethylene to `form butadi
ene. .The last-mentioned procedure has not
found wide commercialA application because the
yields of desired product, were made relatively low
plying, in accordance with my invention,.addi`tional acetylene .to the, reaction Zone as` it is con
co
ferred to total ethylene plus acetylene supplied
amounts of other products stable under the ,pre
‘i
t
' ,
for the reaction step. A concentration of buta
diene results which is, substantially in excess of
that obtained by exposureof a stream of react
.
. I'have now` found that I can successfully pro.
duce substantial yields of low-boiling dioleñns,
ants to one or to two consecutive pyrolytic con
such as butadiene and pentadienes, from relatively
version steps, in` which all reactants, in admix
ture, enter and. pass through a conversion ’zone
more saturated hydrocarbons of two to four .car
bon atoms per molecule by a process which in-V
or zones.
volves cracking or pyrolyzing the more saturated f
hydrocarbons and effecting combination `of por
tions of the cracked products in a co-reaction
step.V The more saturated hydrocarbons are
those which are less unsaturated than the diole
fins; i. e.) the parafûns, ethane, propane, n. bu
acetylene, treating the resulting` mixture to ob
>tain a fraction which comprises ethylene and
acetylene in a suitable ratio, subjecting `said
\
'
`
.
A
_`
My invention further comprises variousfpre
ferred methods for obtaining the desired `-ratio of
hydrocarbons of the oleiin series to hydrocarbons
of the acetylene series, and effecting reaction to
obtain substantial production of the desired prod
uct.
tane, isobutane, and the `oleiins, ethylene, pro.-V
pylene, the butylenes, etc. In one specific em
bodiment, my invention comprises cracking a
charge stock composed predominantly of' satu
rated hydrocarbons of two to four carbon'atoms
per molecule under conditions adapted to eiïect
production of optimum yields of ethylene and
sumed, a totaladdition of :many times the de
sired steady` state .concentration may be made
with resultant increase in the percentage o_f ‘bu
tadiene toÍ6 to 10 per cent by Weight or more, re
by concomitant reactions that vformed excessive
vailing operating conditions.. .
.
ing reaction, as well as the crackingsteps, may
carbons -of two to four carbon atoms perwmole
Qule. `It is especially applicable to` the produc
arewell known.
‘
ther the yield of butadiene. The dioleiin-formà
'
An object of this invention is to provide an im
proved process for the manufacture` of dioleñns.
Another object of this invention is to provide an
improvedrprocess for the manufacture ci dioleñn
khydrocarbons from paranin and oleñn hydrocar
bons having a lesser number of carbon `atoms per
molecule. AnotherI object of ~ this invention is
to provide such a process which involves a com
bination of cracking and co-reactionsteps. . Still
_ another object of this invention is to provide an
fraction to reaction in a turbulence chamber or
improved process for the manufacture. of buta
diene from ethylene and acetylene. - Still another
object is` to provide an improved processV for the
multi-point reactor under conditions favorable
for' the production of butadiene, and separating
and recovering the desired butadiene so produced. ‘ » , manufacture of pentadiene from propylene and
Oi the butadiene-depleted material, a‘fraction`
comprising unreacted ethylene and/or acetylene
may be advantageously recycledY to the reaction
50
improved process for-the production of dioleñns
Another object is
to providesuch a process in ,which the _per-pass
, from an oleiin and acetylene.
zone. to increase the yield of butadiene,_ and Va
fraction comprising relativelyheavy Icy-products
may be advantageously .cracked to increase fur
acetylene. Stillanother object is to provide an
55
conversionof the oleñn. andA acetylene to dioleiins
is higher than heretofore possible.
2,411,256
sired fractions. Hydrogen and methane are
drawing.
withdrawn through pipe I6 and valve Il, and any
heavy oils and/or tar-like products are removed
from the system through pipe i8 and Valve I9.
I have found that low-boiling diolefin hydro
carbons, such as butadiene and pentadienes, may
be produced in high yields from more saturated
carbons of the ethylene series and of the acet
. Lf'
4
and valve I4 to fractionating means l5, which
may be any system of conventional fractional
distillation units suitable for separating the de
» Other objects and advantages of the invention
will be apparent to those skilled in the art from
the following description and the accompanying
hydrocarbons _of two to -four carbon atoms per
molecule-by reacting gaseous unsaturated hydro
» 'ÍÍ
. The remaining pyrolysis products, comprising
the ethylene and the, acetylene, are passed
10 through pipe 2|, controlled by valve 22, to heater
24, wherein they are heated to the temperature
ylene series under selected reaction conditions
that minimize side reactions. More specifically,
substantial yields of butadiene (or pentadiene)
of incipient reaction or just slightly below a re
action-sustaining temperature. Then they are
-
passed through pipe 25 to reaction z_one 26, in
are obtained by reacting a mixture comprising
coreaction to form butadiene is effected.
ethylene and acetylene (or propylene and acet 15 which
I have found that, for optimum yields o‘f
ylene) in a molal ratio of from about 10:1 to
50:1 at a suitable reaction temperature‘in a tur
bulence chamber of the type described in my co
butadiene, the'ratio of ethylene to acetylene in
the reacting gaseous mixture should be in the
range of about 10:1 to 50:1 by volume. If the
nature and composition of the material charged
pending application, Serial No. 373,047, ñled Jan
uary 3, 1941, now U. S. Patent 2,330,118, issued 20 to the pyrolysis zone or the conditions of the
September 21, 1943. The mixture is introduced
reaction* are such that the desired lratio ofV
ata high linear velocity in a direction and man
ethylene ~to acetylene is not directlyj obtained;
ner'such that a vigorous turbulent circulation of
additional‘quantities of the component which
the reaction mixture within the chamber ,is es
is deficient may be added. For example, eth
tablished and maintained, whereby rapid mixing 25 ylene or ethylene-rich gases Vmay be ‘added
and dilution of the incoming hydrocarbons with
through pipe 2l, controlled 'by valve 28,l to pipe
the` already present circulating and reacting con.í
2|.
Similarly, acetylene, or acetylene-rich
tents of the chamber is effected. By effecting
gases, `may be introduced through pipe ‘30, con
such rapid mixing anddilution of the incoming
trolled by valve 3|', to- pipe 25; or therf'acet
hydrocarbons, the co-reaction of ethylene and
ylene may be added directly to the reaction zone
acetylene to formbutadiene 1s favored, and the
through Valve 32 and pipe 33, provided' that it
is suiiiciently> rapidly> mixed and diluted with
formation of ’ polymers of ethylene and/or of
acetylene isminimized. Reaction temperatures
the reacting contentstherein.
»
.
may be in the range of 550 to 900° C. at pressures
‘ Reactionl'zone 26 is preferably a turbulence
of 0.2 to 2 atmospheres, or in the'range of` 300 35 chamber of the type described in my> above#
to 550"> C; at higher pressures, up to about 20 at
identified patent,.2,330,118. iBriefiy, itïcomprises
-va chamber of relatively large cross section, rela
tive to the hydrocarbon stream, into which the
bons of the ethylene series and of the acetylene
reaction mixture'V is introduced ata high linear
series usedv for the formation of. low-.boiling di 40 >velocity and in .aY direction and manner. such
olefins maybe obtained from any sourceV or pro
thatV a circulation ofthe contents of ,the chamf
mospheres.
‘
“
‘
‘
Although the gaseous unsaturated hydrocar
duced by any of variousA methods known to the
art, I preferY to crack hydrocarbons of >two to four
Vcarbon atoms . per molecule, or mixtures thereof,
which are more ‘saturated than the dioleñn hy
ber is establishedand maintained; thereby.l ef
fecting a rapid> mixing and dilution of'thein
ll5
drocarbonsgat temperatures in the range of 850
to 1500°` C.A and at pressures of 0.2 to 3 atmos
culating and reacting contents of the `chamber
through constant and turbulent circulation,
»which advantageously is` augmented through
multipoint-wise',l addition» of the incoming` hy
drocarbons, minimizes formation of‘polymers‘of
ethylene and/or of acetylenaand it simultane
ously favors interactionY ofY ethylene and -acet
pheres for periods of time suiiicient to‘yield eth
ylene and acetylene hydrocarbons in amountsfof
about 15 and 5 per centby weightrof the charge,
respectively.
.'
Y
p
‘
My vinvention will now be more specifically
described in connection with the `accompanying
drawing, which is a diagrammatical flow diagram
' showing one mode of procedure for practicing
my
invention.
`
,
Y
_
dioleñn hydrocarbons and of two to four carbon
the art for effectingV and maintaining pyrolysis
60
higher pressuraup to about 20 atmospheres, are
employed, _the temperatures maybe reduced to
the range of 300 to 550° C. The average time of
residence-of the hydrocarbons in reaction iZone
26 is preferably chosen sol as to -produce the
optimum vyield of butadiene. The reaction mix
65 ture is withdrawn substantially continuously, or
intermittently at suitable time intervals'` if pre
ferred, from reactionl Zone or chamber `26 through
or cracking` of low-boiling hydrocarbons. (The
hydrocarbon charge Vmay be augmented'by re
cycled material from pipe 44, controlled by valve
45.) The pyrolysis Vis prefer'ably‘effectedat 350
to 1500° C. andfat 0.2'Ytof3V-atmospheres,.depend
ing upon theyco'mp’ositiorif 'of theèchargefsto'ck‘;
the reaction time is such asïto convert about 1' to
pipe 35,l whoseV opening «is preferably» located
at` a central point in zone 2S so that short-cir-`
>cuiting of the reacting stream or Streamslis
avoided. It is passed to separating means V35,
wherein-separation into desired fractionsis ef->
fected byffractionation, absorption, extractionor
5 per cent of the chargeby weight-to acetylene .
other suitable means known to the art. VOneof
and about ,15 per cent or more to ethylene; `The
resulting product's‘lare passed 'through"pipe‘V I3
.
at temperatureszwithin> the range of 550 to 900°
C. and at. pressures of 0.2 to 2 atmospheres.V >If
l
zone l2. Pyrolysis zone l2 is heated by suitable
Yheating units, or furnaces, or the like known to
ylene to ,form butadiene.
Reaction within zone .26 is preferably eiîected
, A vhydrocarbon material more-’saturated-'than
atoms per molecule, which> may be> predominantly
ethane, propane, butanes, or; mixtures thereof,
is introduced into'the system through pipe I0
'and isgpassed by way of -Valve Il rto pyrolysis
coming hydrocarbons with the circulating andy
reacting contents. The rapid‘mixingand dilu
tion of the incoming hydrocarbons >with >the cir
75
these fractions comprises chieflylbutadieneand
2,411,256
is withdrawn through pipe 31 and valve 38.
Methane and hydrogen may be removed through
pipe 40 and valve 4|; and any oils and/or tar
like by-products may be withdrawn from the sys
tem through pipe 42 and valve 43.
A fraction comprising chieñy unreacted nor
mally gaseous hydrocarbons heavier than
methane is passed from separating means 36
through pipe 44. If predominantly parailînic,
6
these conditions 17.3 per cent of the ethylene re
acted to yield a cracked product stream contain
ing 3.95 per cent by weight of butadiene. The
butadiene yield amounted to 22.8 per cent by
weight of the ethylene reacted.
Example II
A mixture of ethylene and acetylene containing
3.24 per cent by weight of acetylene was reacted
it is reintroduced to pyrolysis zone i2 by means 10 as outlined above at 881° C. and 0.139 second.
of valve 45 and pipe I0 to be subjected to further
The cracked products stream contained 2.0 per
cracking. If it comprises appreciable quantities
cent by weight of acetylene, 77.9 per cent of eth
of unreacted ethylene and/or acetylene, it may`
ylene and 5.4 per cent of butadiene. The yield
be passed from pipe 44 through pipe 46 and valve
of butadiene was 26.9 per cent by weight of the
41 to pipe 25, so that it is mixed with the stream
C2 hydrocarbons reacted.
of cracking products to reaction zone 26; how
Example III
ever, it preferably is passed from pipe 44 through
pipe 48 and valve 49 to pipe 2|, so that it is mixed
A mixture of ethylene and acetylene contain
with the stream of cracking products before this
ing 2.50 per cent by weight of acetylene was
stream is heated to a temperature of incipient 20 cracked at 871° C. and 0.229 second at 256 mm.
reaction.
v
If desired, reaction products intermediate in
carbon content and molecular weight between
butadiene and heavy oils and/or tar, may be
passed from separating means 36 through pipe 25
5|, controlled by 4valve 52, to cracking Zone 53.
Ii desired, other hydrocarbons or diluent gases
may be added through pipe 54, controlled by
of Hg absolute pressure. The cracked products
contained 2.86 weight per cent of acetylene, 83.50
per cent oi ethylene and 4.96 per cent of butadi
ene. The yield of butadiene was 36.5 per cent by
weight of the C2 hydrocarbons reacting.
Example IV
In a single-pass experiment made to show the
valve 55. Within zone 53, cracking is effected
eiîect of a large percentage of acetylene, a mix
under conditions similar to those in zone I2, 30 ture of ethylene and acetylene containing 27.56
preferably at pressures of 0.1 to 2 atmospheres
weight per cent of acetylene was cracked at 810°
and temperatures in the range of 850-1500° C.
C. and atmospheric pressure in a quartz coil.
depending upon the composition of the material
being cracked. The products from cracking
The time of residence at reaction temperature
was 1.218 seconds. The cracked products stream
zone 53 are passed through pipe 56 and valve 51 35 contained 9.81 weight per cent of acetylene, 53.86
to separating means 58; however, any desired
per cent of ethylene and 4.55 weight per cent of
portion of the products may be passed from pipe
butadiene. In addition the cracked products
56 through pipe 50, controlled by valve 60, to
stream contained 24.04 weight per cent of C5 and
catalytic cracking zone 6|, wherein further
heavier products.
cracking is effected by catalysts such as alumina 40
The invention may be practiced otherwise than
or bauxite, and the eil‘luents are passed through
as speci?cally described or illustrated, and many
pipe 62, controlled by Valve 63, to separating
modifications and variations Within the spirit and
means 58.
scope of it will be obvious to those skilled in the
Within separating means 58, separation into
art.
i
desired fractions is effected by any suitable
I claim:
means. A butadiene fraction is withdrawn
1. The process of making butadiene from eth
through pipe 64 and valve 65. Methane and hy
ylene and acetylene which comprises passing a
drogen are removed through pipe 66 and valve
mixture consisting of ethylene and acetylene in
61. Heavy oils and/or tar are withdrawn
a molal ratio of from 10:1 to 50:1 through a re
through pipe 68 and valve 69. Intermediate , action
zone, maintaining the reaction mixture in
products, other than the butadiene fraction, are
said zone at a temperature of from 871 to 881° C.
passed through pipe 10, by means of valve 1|,
and under a pressure of from 0.2 to 2 atmos
to pipe 2| to be passed with the fractionated
pheres,
holding the reaction mixture in said zone
pyrolysis products from fractionating means l5
for a period of time within the range of from
through heater 24 to reaction Zone 26.
55 about 0.14 second to about 0.23 second, Withdraw
In some cases, with suitable charge stock, it
ing the reaction mixture from said zone and re
may be unnecessary to fractionate the pyrolysis
covering the butadiene content thereof as a prod
products 'before reacting them under conditions
uct of the process.
favorable for production of butadiene. In such
2. The process of making butadiene from eth
cases, the products formed in pyrolysis zone i 2
will pass through pipe 12', controlled by valvei13, 60 ylene and acetylene which comprises passing a
mixture consisting of ethylene and acetylene con
to heater 14, and then through pipe 15, con
taining 3.24 per cent by weight of acetylene
trolled by valve 16, to pipe 25 and reaction
through a reaction zone, maintaining the reac
zone 26.
tion mixture in said Zone at a temperature of
Example I
65 881° C. and at atmospheric pressure, holding the
reaction mixture in said zone for 0.139 second,
Pure ethylene was cracked at atmospheric
withdrawing the reaction mixture from said zone
pressure by flowing it through a narrow quartz
and recovering the butadiene content thereof as
tube maintained at 854° C. by a salt bath. The
a product of the process.
flow rate was such that the residence time at
70
reaction temperature was 0.16 second. Under
FREDERICK E. FREY.
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