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Патент USA US2405395

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Aug. 6, 1946.
W. H. BAHLKE ETAL
'ACETYLENE PROCESS
Filed Jul'y 31, 1943
_2,405,395
, 2 sheets-sheet-l
` Patented Arias, 1,946-
f A2,405,395
UNITED STATES PATENT oFFlcE
wa... n. ÉÍÍÄÍÈÈÍÄÍ‘ÍÍÍÍÃ... T. C..- l
penter, Flossmoor, lll., assignors to Standard
Oil Company, Chicago, Ill., a corporation of In
diana
„
‘
Application July 31, 1943, Serial No. 496,904:
6 Claims. (Cl. 26o-679)
1
This _invention relates to a process-»and appa
fer material which is maintained in turbulent
ratus for making acetylene. One object of the
suspension -by .the `upfiowing vapors. The solid
invention is to provide a process for making acet
employed for this purpose is a refractory mate
rial, generally a metal oxide, 'carbide o'r metal
ylene continuously by the treatment of hydro
carbon material at high temperature. Another
capable of withstanding high temperatures of the
object of the invention is to make acetylene from
order of 2500 to 3000” F.y without fusion. Cal
hydrocarbon material with better yields than
cium, magnesium, or aluminum oxides, corundum
heretofore obtainable from similar processes by
and silicon carbide or carborundum are exam
maintaining more uniform temperatures within
ples. Carbon in the form of coke or graphite
the critical conversion region for acetylene pro .0 may also be used. Tungsten is an example of a
duction; Still another object of the invention is
suitable metal winch may be used in granular
to provide the heat required for the acetylene
or powdered form. '
conversion reaction in a simple manner with low
The reaction chamber I2 is suitably lined with
- fuel cost, low heat losses and avoidance of heat
refractory brick and the temperature is main
transmission thru the walls of heating tubes or 15 tained at about 1800 to 2500° F. and in some
reaction chambers.
-
cases as high as 3000° F. An operating tempera
ture of 2000 to 2300° F. is preferred. Heat is
The invention is illustrated by drawings which
show diagrammatically in Figure 1 an appara
supplied entirely by continuously introducing
tus for carrying out the process in which the ‘ into the reactor I2 the superheated contact ma
heating zone is positioned directly above the re 20 terial by line I6 leading from heating chamber '
action zone. Figure 2 shows a modification in
I1. In chamber I'I which is suitably superim-l
which the reaction zone is positioned above the
heating zone. This modification is especially
adapted to conducting the reaction at sub-at
posed on reactor I2 the contact material isïrdi
rectly heated by combustion of carbonaceous
matter mixed therewith or deposited thereon.
mospheric pressure. Referring to Figure 1, hy 25 Combustion is effected by a blast of preheated
drocarbon feed is introduced at I0 and is pre
air introduced at I8 thru'exchanger I9 and'n'o'z
heated in exchanger II, flowing thence into re
zle 20. The contact material is heatedli'n the
actor I2 containing a turbulent solid heating
preheater to a temperature well above the tem
material in granular or powdered form. For our ,
perature of the reactor I2, for example 100 to
purpose we may use almost any hydrocarbon '30 500° F. and preferably 200 to 300° F. above.
as a feed stock for our process. Methane or other
The contact material, referred to »hereinabove
hydrocarbon is suitable, for example ethane,
as a sub-divided solid material, may be a powder
ethylene, propane and butane. We may also use
of about 20 to 100 mesh. When using high va
napthas or gas oil. Residual petroleum oils and
por velocities, the contact material may be in
tars' from the distillation of coal or shale may 35 granular form having grains of 1A to 116 inch or
also be employed, generally in regulated amounts
fed simultaneously with lighter hydrocarbons
less. The settling tendency of the sub-divided
solid is opposed by the lifting action ofthe up
' such as methane or other hydrocarbon gas rich
flowing vapors in the reactor with the result that
in hydrogen. We may also charge hydrogen
contact material is maintained in suspension by
to the process simultaneously with the feed and 40 the phenomenon of retarded settling. This proc
for this purpose we prefer to employ hydrogenous
ess results in the formation of a “dense phase”
product gases separated in the process. Gas for
in which the suspended particles of solid in rapid
this purpose is introduced to the reactor by line
motion exert an influence on one another to
I3 as hereinafter described.
maintain a relatively constant density depend
Steam may also be introduced into the reactor 45 ing on the various factors involved, such as the
I2 by line I l, the amounts being adjusted depend
ing on the amount of gas recycled, the charac
A
ter of the hydrocarbon feed stock, and the de
sired ratio of solid material to vapor. Steam and
gas are preheated in heat exchanger I5, employ 50
particle size, the density of the contact material
itself and the upflow vapor velocity in the reac
tor. This “dense phase” will ordinarily have a
density of about 10 to 100 pounds per cubic foot
but lower densities of the order of 2 to 5 pounds
ing for the purpose heat otherwise wasted in
A per cubic foot may sometimes be encountered,
the process, or heat from an outside source.
In reactor I2 the hydrocarbon gases and vapors
especially with solids of low specific gravity such
as magnesium oxide. Densities of 15 to 25 pounds
and/or hydrogen and steam flow upwardly in
per cubic foot‘are satisfactory while the higher
contact with the sub-divided solid heat trans 55 densities of the order of 35 to 100 pounds per
2,405,395
I
cubic foot maybe encountered in _case of solids o_f
high specific gravity such as carborundum and
particularly powdered tungsten,
4
or ethyl acetate also lmay be used for this PUT*
pose.
'
.
,
_
The solvent is introduced into the absorber by
line 42 and unabsorbed gases, principally ethanc,
ethylene and propane, are discharged by vapor
line 43. The‘solvent and dissolved acetylene are
.
One of the fundamental characteristics of the
suspended dense phase reaction zone is the unl
formity of temperature resulting from the rapid
migration of solid particles from top to bottom
conducted by line 44 to stripper 45 from which '
>and back and from side to side. As a result any
acetylene is removed by line 46 while the solvent is
tendency toward overheating or cooling is in-l , recycled thru pump 41 and line 42. If desired,
stantly prevented fromv developing local hot zones 10 the acetylene may be retained in solution in the
solvent. e. g. acetone, in which it is very highly
soluble when maintained under pressure.
The gases eliminated from absorber 32 by line
iarly. preheated material introduced at I6 is al
most instantly equalized in temperature with the
I3 are comprised chiefly of hydrogen and methane
material alreadyin the reactor I2. As a result 15 with a small amount of other hydrocarbon gases.
the temperature thruout reactor I2 is> maintained
As hereinbefore indicated, these gases may be
uniform generally differing not more than 5° and
recycled to reactor I2 in sufficient amount to
not more than 25° F. at the maximum.
maintain the desired reaction conditions for the
The time required for the passage of hydro
vformation of acetylene from the hydrocarbon feed
or cold zones in the reactor by vreason of the
rapid mixing and redistribution of heat. Sim‘i- ‘
carbons thruthe reactor is maintained short in 20 supplied by line l0._ Methane in the recycle gas
order to ‘avoid secondary reactions resulting in
is also converted to acetylene in the reactor.
In the operation of quench tower 22, sufllcient
the loss of acetylene. A reaction timeof about
water or oil-quenching liquid is charged byline
0;1 to 1 second is preferred although longer reac
23 to maintain a liquid phase in the quench tower,
tion time may be used, for example 5 to‘10 seconds,
particularly when charging methane as the hydro 25 thereby providing a Washing action for the prod
uct vapors and removing therefrom suspended
carbon feed stock and when introducing substan-y
tial amounts of steam and/or hydrogen. ï The . ycontact material which may be carried over from
Contact material in suspension is
' reactor I2.
amount of steam or hydrogen introduced with the
conducted from the quench tower by line 48 lead
feed stock is preferably about 5 to 50 mols per mol
of hydrocarbon'introduced. ’
"
30 ing to separator 49 provided with overñow 50 for
the withdrawal of oil in case water is employed
The reaction products are conductedfrom` the
as the quenching liquid. In case oil is employed
reactor by line 2I leading `to quench tower 22'
as a quench liquid, the recovered quench oil may
where the temperature is instantly reduced-to a
point where acetylene decomposition is slow, byl
be recycled thru lines 50 and 54 back to quench>
tower 22. In case water is employed for quench
contact with a current of water or oil supplied by
ing, it may be returned directly from the base
line 23. Additional quench liquid, preferably
of tower 22, with solids in suspension, to quench
water, may be introduced by line 24 and directed ,
the reactor at 25, thus returning to the reactor
into line 2I_ at the outlet from reactor I2 or
Solids lost in the product vapors. The slurry from
directed by valved line 25 into the upper part of
reactor I2' itself above the level of kiliiidized solid 40 the base of separator 49 is conducted by line 5I
to settler 52 wherein the solid contact material
therein. The product gases thencefiowl by line
may be removed from the quench liquid by line
26 to condenser 21 from which the water or quench l
53. Part or all of the recovered solids may be
oil, and suspended solid particles escaping from
recycled by line 54 for use in quenching in 22
the quench tower, is condensed and _discharged
into separator 23. Accumulating oily reaction 45 or elsewhere, but where the solids have a low value
they may be discarded. If desired, recovered
products are withdrawn from the separator by
contact material may be dried -and returned to the
line 29. Uncondensed gases including acetylene
reactor for further use.
,
are conducted by line 30 and compressor 3| to
Additional contact material may be supplied as
absorber 32 wherein acetylene and‘heavier hydro
carbons are absorbed in an absorbing oil intro 50 makeup to the reactor-preheater system thru
hopper 55 controlled by valve 56. Additional solid
duced by line 33. The pressure employed in the
fuel to supply heat for the process may also be
absorber is suitably about 100 to 300 pounds per
introduced by hopper 55, for example granulated
square inch but may be much highenfor example
or powdered coal or coke may thus be introduced.
1000 pounds. The rich oil withdrawn from ab- ,
. sorber 32 by line 34 is reduced in pressure at valve 55 Coal may also be supplied directly to reactor I2>
35 and thence enters fractionator 36, wherein
acetylene and light hydrocarbons are discharged
thru vapor line 31 and the denuded oil is -recycled
thru line 38 and cooler 3S. The light hydrocarbon
by `means not shown. Thus powdered coal may
be blown into the reactor I 2 by a current of steam.
‘ In starting up operation of the process, the pre
heating chamber I1 may be heated to tempera
e. g. 2000“ F., by a blast of gas and air sup
fraction containing principally C4 hydrocarbons 60 ture,
plied by burner 51 and simultaneously contact
including butadiene, butylenes. butanes ~and '
material, e. g. carborundum, may be introduced
at 55 and recycled thru the system'. The contact
propylene may be withdrawn by trapout line 40.
material is withdrawn from the base of reactor I2-.
It should be understood that the fractionator 65 and returned to the top oi' preheater I1 by a suit
shown is diagrammatic and a plurality of towers,
able conveyor, for example, a hot blast thru an
perhaps operating at different pressures may be
insulated line involving a minimum of heat loss.
heavier hydrocarbons with some propane and
employed.
-
>
_ The vapors and gases withdrawn from frac
'
Thus a blast of air introduced at 58 is preheated '
in exchanger 59 and injected into eductor 60 where
tionator 36 by line 31 are conducted to absorber 70 the contact material is received from reactor I2 .
- and carried thru line 6I to cyclone separator 62.
24| wherein a selective solvent ¿for the recovery
Separator 62 serves to recover solids from the
y of acetylene is employed. For this purpose
combustion gases leaving heater I1'by duct 63 and
alcohol, e. g. methyl, ethyl or isopropyl alcohol,
also provides heat exchange between those gases
may be employed. Acetone, glycol monoformate,
glycol monoacetate, mono or diacetates of glycol, 75 and the solids recycled from reactor I2. The re
2,405,395
covered solids then ñow by duct 64 back to the
heater I1, preferably below the surface ofthe tur
charged via line 83 while recovered solids ilow>
back to-the heater'by duct 84. The reheated
bulent layer of powdered solids therein. In the
solids, for example, at a temperature of 2500“ F., `
operation of the heater I1 the turbulent solid heat ‘
flow by line 86 back to reactor 1| being impelled
by a jet of conveyor gas introduced by line 86.
carrier forms a pool which continually overflows
into duct I 6 leading to the reactor I 2, thereby
The amount of gas required for this purpose may
be only sufllcient to aerate the solids somewhat
In preheater I1 it is preferred to maintain the
and reduce the density of the suspension.
contact material in dense phase suspension, with
It is preferred to operate the heater 18 at a
a density of about 5 pounds to 25 pounds per
pressure slightly above atmospheric and to main
cubic foot, although much higher density may 10 tain the pressure differential between the heater
be employed, particularly in the case where very
and the reactor 1I by means of the column of
dense heat carrier solids are used. Thus with
aerated iluidized solids in duct 11 which acts as
carborundum, densities of 50 to 'I5 pounds per
_a standpipe. In this way the tremendous ex-_
cubic foot may be employed. The heat resulting
pense of exhausting the combustion gases from
15
from the combustion of carbonaceous material
heater 18 is avoided.
from the carrieris employed to preheat the con
Having thus described our invention what we
tact material to a uniform accurately controlled
claim is:
temperature for use in the reactor I2, thereby
1. The process of making acetylene which com
stabilizing the operation of the process.
prises contacting hydrocarbons with iìne granu
‘ maintaining a level resembling that of a liquid.
For reasons of heat economy the hot gases dis» 20
lar solids maintained inturbulent -dense phase
charged from separator 62 may beconducted by
line 65 thru heat exchangers I9, ll and 59 as
suspension by passing the vapors of said hydro
preheater special refractory linings must be used,
» by direct contact with combustion gases, main
carbons upwardly through a reaction zone in
indicated. Any residual solid contact material
contact with said granular solids at a velocity
carried away by the combustion gases may be
suiiicient to provide for hindered settling of said
recovered in electrical precipitator 66 orby scrub 25 solids,
maintaining the temperature of said re
bing with a suitable scrubbing liquid or by other
action
zone above .1800° F. by introducing into
means. The combustion gases may then be em
said reaction zone a stream of hot granular solids
ployed as a low grade fuel gas and have a fuel
at a temperature substantially above the tem
value comparable to that of producer gas owing
perature
of said reaction zone, withdrawing sol
30
largely to their carbon monoxide content. '
ids from said reaction zone at the temperature
It should be understood that on account of the
thereof and reheating them in a preheating zone
high temperatures employed in the reactor and
taining the solids in said preheating zone in
and where metals are exposed to the gases high
melting alloys such as chrome-nickel alloys, e..g. 35 dense ?luidized turbulent suspension by upfiow
ing combustion gases, maintaining an excess of
Calite, Chromel, etc. may be employed.
'
carbon in association with said solids beyond that
In order to obtain maximum yields of acetylene,
consumed by combustion in said preheating zone,
it is desirable to operate the reactor at low pres
maintaining
a higher pressure in said preheating
sures, generally atmospheric pressure or below.
40
zone
than
the
pressure in said reaction zone,
Sub-atmospheric pressures may be obtained by
transferring a dense fiuidized stream-of solids
operating pump 3l as a vacuum pump or ex
from said preheating zone back to said reaction
hauster. When conducting the reaction at sub
zone
through a column of suflicient height to
atmcspheric pressures it is _advantageous to em
ploy the arrangement of reactor and heater 45 provide a hydrostatic back pressure substantially
equivalent to thel pressure diiferential between
shown in Figure 2. '
said
preheating zone and said reaction zone.
Referring to the drawings, Figure 2, methane
withdrawing reaction products from the upper
or other hydrocarbon feed stock is supplied by
~part of said reaction zone and recovering acetyl»
line 10 to reactor 1I maintained under diminished
ene therefrom.
pressure, for example 0.2 to 0.9 atmosphere. The 50
2. The process of claim 1 wherein the preheat
conversion of the hydrocarbons to acetylene and
ing zone is maintained at a temperature of about
carbon is effected by the heat of. the ñnely di
200 to 500° F. above the temperature of said re
vided solid heating medium with which the re
action zone.
.
,
actor is substantially ñlled. The reaction prod
3. The process of making acetylene by contact
ucts escape by line 12 to a suitable exhausting 55 ing'a hydrocarbon vapor with a iluidized mass of
and acetylene recovery system. Quench liquid
hot refractory solids at _a temperature in excess
may be injected at 13 and/or 14 to prevent the
of 1800° F. in a reaction zone, introducing the
loss of acetylene by secondary reactions at lower
said hydrocarbons at a low point in said reaction
temperatures. Recycled gases, e. g. methane
at sufficient velocity to maintain said mass
and/or hydrogen, may be introduced into the 60 zone
of
solids
in iluidized dense phase condition, with
reactor by line 15 and steam by line 16.
drawing reaction products from the -upper part
'I‘he iluidized solid heating materialv in suspen
of said reaction zone, transferring a stream of
sion in gas overflows from reactor 1I into duct
ñuidized
solids from said reaction zone to a heat
11 leading to heater 18 where the temperature
exchange zone where they are contacted with hot
is restored by combustion with air introduced at 65 combustion gases withdrawn from a combustion
19. Additional heat may be supplied by burner
zone, transferring heated solids in a ñuidized
80 when desired but generally the amount of car
stream from said heat exchange zone to saidbon deposited on the heating material is more
combustion zone for further heating therein by
than suiiicient to supply all the heat necessary
a combustion reaction, discharging combustion
` when blasted with air, and it is desirable to leave 70 gases
from said heat exchange zone after con
a deposit of unburned carbon on the heat carrier
material to insure that the reheated material
carries no oxygen back to the reactor.
Combustion gases from heater 18 ñow by duct 1
- 8| to cyclone separator 82
tacting with said solids and conveying a ñuidlzed
stream 'of solids from said combustion zone to
said reaction zone, the vtemperature of said con
veyed solids being substantially above that ot`
and thence are dis` 75 said reaction zone.
_
'
m
p
9,405,395
, 6. The process of claim 1 wherein said reaction
zone is maintained at a. pressure of about 0.2 to
_' 4.
process of claim 1 ’wherein 'the vapor
velocity within said reaction zone is controlled
to provide a suspension of granular solids having
1.0 atmospheres and the preheating zone is main
tained above atmospheric pressure.
’ a density within the range ox bout'â to 50 pounds
per cubiefoot.
v
5. The process of claim 1 wherein the tempera
ture oi' said reaction -zone is maintained within
the range of. about 2000 to 2500’ F.
5
Will-IAM H. BAM.
MORRIS T. CARPENTER.
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