July 6, 1954
N. l.. DlcKlNsoN
PREPARATION oF HYDRocARBoN SYNTHESIS GAS
Original Filed Sept. 27. 1947
2,683,152
July 6, 1954
N. l.. DlcKlNsoN
PREPARATION OF‘ HYDROCARBON SYNTHESIS GAS
i 2,683,152
Patented July 6, 1954
2,683,152
UNITED STATES
ATENT oFFlcE
(i
PREPARATION 0F HYDROCARBON
SYNTHESIS GAS
vNorman L. Dickinson, Basking Ridge, N.. J., as
signor to The M. W. Kellogg Company, Jersey
City, N. J., a corporation of Delaware
.
Continuation of application Serial No. 776,518,
September 27, 1947. This applicationfNovem
ber 28, 1951, Serial No. 258,730 .
1
8V Claims.
(Cl. 252-373)
2
'I‘his invention relates to the synthesis of or
ganic compounds. In one aspect this invention
relates to the production of a gas rich in hydro
gen, useful for the synthesis of organic com
-pounds. In another aspect this invention relates
to an integrated process involving the produc
tion of hydrogen and an oxide ofk carbon and
the subsequent interaction of the hydrogen and
the oxide of carbon in the presence of a hydro
a normally gaseous hydrocarbon into normally
liquid hydrocarbons.v
provide a single integrated process for the pro
duction 'of both oxygenated organic compounds
and hydrocarbons as products of the process.
Another object of this invention is to pro
vide a more economic process for the synthesis of
organic compounds from methane.
genation catalyst to produce hydrocarbons hav
`
This application is a continuation of my appli
and disclosure.
cation Serial No.776,518, ñled September 27, 1947,
„
now abandoned.
cous mixture comprising hydrogen and carbon
monoxide may be produced either by the partial
to hydrogen and carbon-monoxide by partial
combustion with an oxygen-containing gas as
combustion of relatively low-boiling hydrocar
the primary reaction in one Zone and by direct
bons, such as methane, or by the reaction of rela
‘ reaction with steam as the primaryreaction in
tively low-boiling hydrocarbons with steam. The
a second zone. The product of the methane con
partial combustion of methane as well as the
version comprising hydrogen and carbon mon
reaction of carbon dioxide with methane to pro
duce hydrogen and carbon monoxide produces
these components in a relatively low ratio with
respect to each other, usually in a mol ratio less
than 'about 2:1 at temperaturesrbetween about
1800 and about 2500" F. On the other hand, the
production of hydrogen and carbon monoxide by
oxide from each zone is combined as a synthesis
feed mixture and passed through a synthesis re
action zone under suitable conditions of opera
tion and in the presence of a suitable catalyst,
such as iron, to produce hydrocarbons having
more than one carbon atom per molecule and
oxygenated organic compounds as theY principal
products of the process. Unconverted reactants,
the reaction between methane and steam pro- I
duces these components in a mol ratio above
carbon dioxide and methane from the synthesis
about 2:1 at a temperature of about 1250 to about
reaction are recycled to one or both of the meth
Either of the above reactions may be
ane conversion zones. By effecting the synthesis
of organic compounds according to this inven
effected with or Without a catalyst. The syn
thesis of hydrocarbons from such gaseous mix
tion thel efliciency of the process may be greatly
increased and a synthesis feed gas of the desired
tures has been effected in the presence of a cata
lyst, such as _a metal> or a'metal oxide in group
VIII of the periodic table, to produce organic
compounds therefrom. Generally the ratio of
hydrogen to carbon monoxide for the synthesis
of hydrocarbons is between about 1:1 and about
3:1, preferably va ratio of about 2:1. It is, there
fore, desirable to provide a method for producing
a synthesis feed having the preferred composi
tion of about 2:1 mol ratio of hydrogen to carbon
monoxide.
composition for optimum yield of normally liquid
organic compounds maybe produced.
It is desirable to use a synthesis feed gas hav
ing a relatively high ratio of hydrogen to carbon
monoxide, such as >a mol ratio of about 2:1,
since the use of a feed ,gas having a relatively
low ratio of hydrogen to carbon monoxide in
creases undesirable side reactions which results
45
y
It is an object of this invention to produce a
synthesis gas comprising hydrogen and carbon
'
According to this invention, methane, or other
normally gaseous hydrocarbon or mixture there
of, is converted simultaneously in separate zones
It has been known for some time that a gas
v 2400" F.
f
Other objects and advantages of the present
invention will become apparent to those skilled
in the art from the accompanying description
ing more than one carbon atom per molecule and
oxygenated organic compounds.
‘
Still a further object of this invention is to
.
in contaminating the synthesis catalyst with car
bon, tars, waxes and relatively high-boiling or
ganic compounds.
For the best understanding of the present in
vention a description of the process according to
t is another object of this invention to pro 50 the accompanying drawings will be undertaken.4
vide a continuous process for the synthesis of
Fig. l of the drawings comprises a diagram
organic compounds from relatively low-boiling
matic illustration of an arrangement of appa
hydrocarbons.
‘
Y
ratus for the manufacture of hydrocarbons hav
Still another object of this invention is to pro
ing more than one carbon atom per molecule and
monoxide in a ratio of about 2:1.
A
vide an integrated process for the conversion of 5.5 oxygenated organic compounds from methane in
'assente
3
a single synthesis reaction unit. The apparatus
of Fig. 1 comprises a methane combustion unit
1, a methane reforming unit ifi, a synthesis re
actor 2l and suitable auxiliary equipment,
Fig. 2 is a modiñcation of the present inven
tion for the manufacture of organic compounds
from methane in which the methane conversion
4
reaction is a function of the ratio of oxygen to
„iethana a specific ratio within the above range
is chosen to give the desired temperature at which
conversion is substantially complete and carbon
Ul formation is minimized. The specific mol ratio
of hydrogen to carbon monoxide in the product
from combustion chamber 1 is between about
1.1' :1 and about 1.8:1 when no tail gas is recycled
products are converted to organic compounds in
from the synthesis reaction system and between
two synthesis reaction units.
According to the illustration of the present lO about 1:1 and about 1.721 when tail gas includ
ing carbon dioxide is recycled. The composition
process of Fig. 1, methane or a methane-contain
ing gas from any suitable source, such as nat
ural gas, is passed under pressure through con
duit 6 to a combustion zone 1. Although meth
ane is referred to specifically as the feed, the
use of other gaseous hydrocarbons, such as ethane
and propane, is Within the scope of this inven
Oxygen or an oxygen-containing gas is
passed to combustion zone 1 through conduit 8.
Methane is preheated, such as by indirect heat
exchange with the combustion products from
of typical reaction eiñuents for the partial com
bustion of methane are shown below in Table II
and it will be understood that such composition
depends upon such operating conditions as tem
perature, ratio of methane and oxygen, etc.
Table II
tion.
combustion zone 1 as shown.
Nocuîâegcy“ Recycling
1.8
4.1
59.6
35.1
2.8
0.7
52.8
37.8
3.5
1.8
Total (Dry Basis) ___________ __do___-
100.0
100. 0
H2200 Ratio ______________________ __
1. 7:1
1.4:1
Oxygen may also
be preheated if desired. In combustion zone 1,
methane is oxidized to hydrogen and carbon
monoxide according to the typical equation shown
below.
Combustion zone 'l may comprise a pressure
Vessel formed of a carbon steel shell ca-pable of
withstanding the pressure of operation and pro
tected from excessive temperature by a cast lin
ing of a suitable refractory material, such as Zir
conia, including a burner fabricated of a heat
Although substantially pure oxygen is preferred
as the oxidizing agent for the methane combus
tion, air or other oxygen-containing gas may be
used also without departing from the scope of
this invention. In order to recover exothermio
heat of reaction liberated in combustion sone 1,
resistant alloy and cooled by circulating Water 35 indirect heat exchange of the reaction products
or steam through it.
When the source of methane is natural gas,
with water to produce steam may be effected in
conduit il as shown. The steam thus produced
the feed gas composition will be approximately
may be used for producing power, for heating
that shown in Table I below:
purposes or may be used in the reaction between
40 methane and steam to be described more fully
Table I
hereinafter.
_
Mol per cent
Simultaneously, with the production of hydro
N2 _____________________________________ __
CO2 ___.' _______________________________ __
1.3
‘0.5
gen and carbon monoxide in combustion unit 1,
methane is continuously passed from conduit ß
CHI
__
___ 79.7
through conduit 12 to reforming unit I4. Steam
C21-I6 __________________________________ __ 12.1
is introduced into reforming unit i4 through con
CSI-Is __________________________________ __
4.7
duit I3. Heat is supplied to reforming unit I3
04H10
_____
1.2
by the combustion of a fuel in indirect heat
C5+
__-__ 0.5
exchange with the mixture of steam and meth
100.0
ane to produce a temperature between about 1400
and about l600° F. Reforming unit lli comprises
The temperature of combustion zone 1 is be
a conventional tubular reforming furnace of the
tween about 1700 and about 2600° F., preferably
type known to those skilled in the art with cata
it is at a temperature of about 1800 to about l900°
lyst in the reaction tubes. The pressure of the
F., when using a catalyst, such as nickel, and a-t a
temperature of about 2350 to about 2500o F. when 55 reaction mixture of methane and steam in the
tubes of the reforming furnace ifi is below about
not using a catalyst. A pressure between about
100 pounds per square inch gage and is prefer
one atmosphere and about 500 pounds per square
ably between about 15 and about 50 pounds per
inch gage corresponding substantially to the pres
square inch, A ratio of steam to methane in the
sure in the subsequent synthesis reaction zone
feed mixture to the reforming unit iii is about
is maintained in combustion zone 1. Preferably, 60
2 mols of steam per mol of methane, although
the reaction is effected with a catalyst compris
higher ratios may be used without departing from
ing nickel or nickel oxide supported on a heat
the scope of this invention. Carbon dioxide may
resistant support as Alundum. The catalyst is
be employed to replace a portion of the steam
usually contained in a stationary bed in various
used. For example, one mol of steam and one
forms, such as pellets or granules, porous tubes 65 mol of carbon dioxide may be employed per mol
of ceramic material impregnated with catalyst,
of methane without departing from the scope of
or tubes of the metal catalyst. The reaction is
this invention. Typical equations for the reac
exothermic requiring only preheating of the
tion of methane with steam and carbon dioxide
methane stream to effect reaction. The mol ratio
are shown below:
of oxygen to methane entering the reaction zone 70
is between about 0.511 to about O.70:1. A reac
tion effluent comprising hydrogen and carbon
monoxide in a mol ratio of less than about 2:1
The interaction of methane with steam or car
is continuously removed from reaction zone i
through conduit Il. Since the temperature of 75 bon dioxide is effected in the presence of a suit
2,683,152
5;
able catalyst in reforming unit I4. Asuitable
reforming catalyst may comprise nickel or nickel
oxide supported on alumina or other supporting
material, such as, for example, a catalyst con
taining in parts by weight 1 NiO, 0.2 CrzOa,
1.6 SiO2, l0.9 MgO. Other reforming catalysts
comprise molybdenum, cobalt and chromium and
their oxides and suliides. The catalyst is con
tained in a stationary bed of granular material
in the tubes. A regenerative type reformer fur
nace constructed of ceramic material may be
used instead of the aforementioned tubular type
furnace. With a regenerative type furnace, tem
v peratures as high as 2400° F. are possible thus
6
ants and reaction products with the catalytic
material is afforded in reactor 2| to produce the
desired product of the process. Usually, a con
tact time of gases and catalyst between about
2 and 20 seconds is appropriate.
A reaction effluent comprising hydrocarbons,
oxygenated organic compounds, steam and un
reacted reactants including some methane, is
removed from reactor 2I through conduit 22 and
10 passed to a primary condensation unit 23. Con
densation unit 23 comprises a conventional con
denser and accumulator and auxiliary equipment
for partial condensation of the efliuent. Unit
23 may comprise a single or a series of condensa
obviating the necessity of a catalyst. A gaseous 15 tion units and accumulators. The temperature
eflluent comprising hydrogen and carbon monox
of the efñuent in condensation unit 23 is reduced
ide in a mol ratio greaterI than about 2:1, usually
to about 300° F. or lower but the eñiuent in con
about 4:1 with no recycle of tail gas, is removed
densation unit 23 is maintained at substantial
from reforming unit I4 through conduit I 8. Such
ly the same pressure as that existing in reactor
a gaseous effluent has arproximately a composi 20 2 I. rI'he cooling of the eñiuent results in the for
tion as shown in Table IlI below when natural
mation of two liquid phases in primary conden
gas is the source of methane. It will be under
stood that the composition of the eñluent will `de
pend uponthe reforming operating conditions,
sation unit 2K3. These liquid phases comprise
a lighter hydrocarbon-rich phase and a heavier
aqueous-rich phase containing dissolved oxy
such as temperature, space velocity, steam to 25 genated organic compounds. Gases comprising
methane ratio, etc.
hydrogen and/or carbon monoxide and includ
Table III
Mol per cent
N2
_____ __'
0.3
H2 ____________________________________ __ 73.5
CO _
18.1
CO2
'CH4
____ __
___
63
1 8
ingsome methane and carbon dioxide are re
moved from condensation unit 23 through con
duit 24 and may be recycled to synthesis reactor
30 2I through conduit 2S in order to supplement the
composition as to any component of the syn
thesis feed in conduit I9 and to'alter the ratio
of hydrogen to carbon monoxide in reactor 2l.
The aqueous-rich phase in primary condensa
Total (dry basis) ________________ __100.0 35
tion unit 23 is removed therefrom through con
The elfluent in conduit I6 is passed through a
cooler I1 for cooling the eiiiuent to a temperature
below about 100° F. to condense the steam in
theV effluent, which steam is removed as ccn
duit 2l and may be passed to subsequent con
ventional separation and recovery equipment
(not shown) for the removal of dissolved oxy
genated organic compounds therefrom as prod
densate from cooler I'I through conduit I5. 40 ucts of the process.
Usually the temperature of the- eflluent is cooled
A portion or all of the uncondensed compo
to about 100° F. before compressing. From
nents of the eñiuent from reactor 2I and the liq
coo'ler Il the reforming unit effluent is continu
uid hydrocarbon-rich phase are removed from
ously passed through conduit I3 and compressed,
condensation unit 23 through conduit 28 and
if necessary (not shown), to be combined with
passed to a 'secondary condensation unit 29 which
the v,effluent of ‘combustion unit 'I in conduit II,
may comprise a lean oil circulating system. Con
The resulting mixture from conversion units 'I
densation unit 29 may also comprise suitable
and I4 is continuously passed through conduit
condensers and accumulators for further con
I9 to a conventional synthesis reactor 2l.
densation and accumulation of reaction products.
Synthesis reactor 2l may comprise any of sev 50 The temperature of condensation unit 29 is main
eral types of conventional reaction chambers,
tained below about 100° F. and a pressure is
such as fixed bed or fluid bed reaction units,
maintained substantially equivalent to the pres
known to those skilled in the art, and may com
sure existing in synthesis reactor 2|. Pres
prise several reactors in series or in parallel.
sures higher than the pressures existing in re
The combined synthesis feed in conduit I9 corn 55 actor 2I and condenser 23 and refrigeration may
p'rises'hydrogen and carbon monoxide in a mol
be employed in connection with> unit 29 with
ratio of about 2:1. This feed is passed through
synthesis reactor 2l in contact with a suitablek
catalyst, such as iron or other metal ormetal
out departing from the scope of this invention.
In condensation unit 25 further condensation
of the gaseous components is effected and the
oxide of group VIII of the periodic table, under 60 liquid hydrocarbon condensateis'removed there
conditions of reaction such that hydrocarbons
from through conduit 3Ifand passed to subse
having more than one carbon atom per molecule
quent conventional separation and recovery
' and oxygenated yorganicy compounds are pro
equipment (not shown) for the recovery of prod
duced as products of the process. The tempera-_~
ucts of the process. Any water condensed in
ture of reaction in synthesis reactor 2l is usual 65 condensation unit 29 is withdrawn therefrom
ly between about 300° F. and about ‘700° F. and>
Vthrough conduit 32. Uncondensed components
a pressure is maintained between about atmos
of the reaction eiiiuent comprising hydrogen
pheric and about 500 pounds per square inch
gage, preferably between about 100 and aboutV
300 pounds per square inch gage. When em
ploying an iron or iron oxide catalyst, a tem
perature between about 450° F. and about 650°
F. is appropriate. When employing a cobalt
catalyst a temperature below 450° F. is em
ployed. Suliîcient contact time between react
and/or carbon monoxide, carbon dioxide,~methane and unrecovered hydrocarbons vheavier than
methane, are removed from condensation unit
29 through conduit 33 and are recycled in whole
or in part to conduit 6 and combustion unit 'i
by means of a recycle conduit 34. A portion or
all of the gases or vapors from the primary con- -
densation unit 23 may also be recycled to .corn-`
2,683,152
available source of synthesis feed gas (CO-l-I-Iz)
and, thus, the recycle of the normally gaseous
components of the synthesis eiiiuent to the
methane conversion units is desirable. The hy
bustion unit 'I through» conduits 24, 34 and 8.
Recycling of gases from condensation units 2?»
and 29 to combustion unit l isdesirable in order
to utilize the relatively high pressure existing on
the gases.
drogen in the recycle gases is not only a source
This pressure is substantially the
of hydrogen for the synthesis reaction, but is
same as the pressure existing in synthesis re
known to decrease carbon or coke formation dur
actor 2! which is usually under a pressure sub
stantially the same as that in combustion unit
ing partial combustion of methane, such as is
effected in combustion unit 1.
In order to prevent the build-up of nitrogen
in the system, particularly when using air as a
1, except for the additional> pressure needed for
the pressure drop required for iiow through the
system, If the pressure in combustion unit 'I
is lower than that of the recycled gases, the
pressure may be decreased by expansion into con
source of oxygen for combustion unit 1, a por
tion of the recycle gases is continuously or inter
` mittently passed to a carbon dioxide absorption
unit 36 through conduits 24 and 31 or conduit 33.
In absorption unit 35 the gases are contacted
with a suitable solvent for the removal of car
bon dioxide therefrom in the conventional man
ner.
Such solvents may comprise mono
20 ethanolamine or other ethanol amines. Nitro
gen and other unabsorbed gases, such as meth
ane, are removed from absorption unit 3% through
conduit 38 and vented to the atmosphere or used
as fuel. Carbon dioxide is recovered from the
duit 6 in which case `compression will be effected
infconduit il or I@ by means not shown. How
ever, if the pressure of the recycle gases is low
er than the pressure existing in combustion unit
"I, a suitable compressor (not shown) must be
provided for raising the pressure of the recycle
gases to the pressure existing in combustion
unit 1. Preferably, combustion unit l is op
erated at substantially the same pressure as syn
thesis reactor 2l with no compression of the
combustion unit eíiluent and in this mann-er of
rich solvent by stripping, by reducing the total
operation only a relatively small amount of com 25
or partial pressure, or by heating, and then the
pression of the recycled gases is necessary.
resulting lean solvent is returned for the ab
Alternatively, the recycled gases from conden
sorption of more carbon dioxide. The desorbed
sation units '23 and 29 may be passed in whole
carbon dioxide is removed from absorption unit
or in part to reforming unit I4 through conduits
dâ through conduit 39 and returned to recycle
34 and 4I without departing from the scope of
conduit 34 for return to either combustion unit
this invention although recycling to reformer I4
“i or reforming unit I4.
is not as desirable in most instances as recycling
With regard to stripping the rich solvent of
to unit ï, Recycling of at least a portion of the
absorption unit 3B by reduction of the partial
recycle gases to reforming unit I4 is particularly
desirable when the synthesis reaction is effected
pressure, as a modification of this invention the
rich solvent containing dissolved carbon dioxide
therein is contacted countercurrently with the
in the presence of an iron or an iron oxide cata
lyst since with such a catalyst the synthesis re
action efñuent contains appreciable amounts of
carbon dioxide. With a reduced iron catalyst
methane feed stream from conduits 6 or l2 and,
as the result of the reduced partial pressure of
carbon dioxide during contact with the methane
stream, the carbon dioxide is desorbed. A meth
ane stream containing the desorbed carbon di
oxide is then passed to either or both of methane
the composition of synthesis reaction effluent
may comprise as much as 20 to 50 per cent car
bon dioxide. As previously discussed, carbon
dioxide reacts with methane and, therefore, re
cycling of the carbon dioxide-rich gases to re
forming unit I4 is particularly desirable and re
conversion units 'I and I4„as desired. By this
method of desorbing carbon dioxide from the rich
solvent, the necessity of heating the rich solvent
sults in a higher methane conversion at given
conditions and in a lower endotherrnic reaction
is obviated or at least minimized and the car
bon dioxide is converted to carbon monoxide in
the methane conversion zones, particularly in
reforming unit I4.
duty per unit of carbon monoxide manufactured
as compared with the use of steam and methane
alone.
The recycled gases in conduit 34
Fig. 2 comprises a diagrammatic arrangement
be passed
of apparatus illustrating a modification of the
in entirety to either combustion unit ‘I or to re
forming unit I4 as will be most efncient and
present invention in which two synthesis reaction
units are employed rather than the single syn
thesis reaction unit of Figure l. For the best
understanding of this modification, a descrip
tion thereof will be undertaken in accordance
economical under conditions of operation, or the
recycling gases in conduit 34 may be divided
and a portion passed to combustion unit 'I and
the other portion passed to reforming unit I4.
A typical composition of recycle gases is illus
with the arrangement of apparatus of Figure 2.
In Figure 2, methane, natural gas or other rela
trated in Table IV below when using an iron
synthesis catalyst.
60
Table IV
Mol per cent
N2 ___________________________________ __
2.4
H2 __________________________________ ___ 47.4
CO ___________________________________ __
6,3
CO2 __________________________________ __ 32.3
CH4 __________________________________ __
8.5
02+ __________________________________ __
3.1
65
tively low-boiling hydrocarbons are continuously
passed through conduit iii by means of a com
pressor (not shown), if necessary, to conduit 52
and thence in indirect heat exchange with the
reaction products of a combustion unit 53 to the
inlet of combustion unit
Oxygen is combined
with the inlet methane stream by means of con
duit 54 and the resulting mixture is burned
under conditions of partial combustion in com
bustion unit 53 under similar conditions and in
70 a similar manner as described in Figure 1. The
preheated methane stream may be combined
with steam injected therein through conduit 5%,
As is evident from the above typical composi
if desired, in order to minimize the formation
tion a considerable amount of hydrogen and
of carbon and increase the conversion of meth
combined carbon is present in the recycle gases.
ane. IThe temperature of combustion unit 53 is
The presence of such components is a readily 75
Total ___________________________ __100.0
2,683,152
10
usually above 1800° F. and in order to recover
at least a portion of the exothermic heat of the
reaction, water may be passed in indirect heat
and a relatively high concentration of 'carbon
dioxide in the recycle gases in conduit 1I not to
recycle such gases to combustion unit 53 because
carbon dioxide requires additional oxygen and
lowers the hydrogen to carbon monoxide ratio
exchange through conduit 58 with combustion
unit 53 to produce steam which may 'oe/used for
heating purposes, for compression purposes or
of the product gas. Normally liquid hydrocar
for use in the reaction between steam and meth
bons and oxygenated organic compounds are
ane. A gaseous effluent comprising hydrogen and
withdrawn from synthesis unit 59 through con
carbon monoxide in a mol ratio less than about
duit 13 and passed through conduit 'it to con
2:1, usually about 1:1 when tail gas is recycled 10 ventional purification and recovery units (not
from the synthesis reaction, is removed from
shown) for the recovery of products of the
combustion unit 53 through conduit 51 and is
process.
.
passed to a conventional synthesis reaction unit
Simultaneously, with the partial oxidation of
59.
methane in combustion unit 53 reforming of
Synthesis reaction unit 59 comprises a con 15 methane is being effected in a reforming unit 63.
ventional stationary or fixed bed reactor or a
conventional fluid bed reactor with suitable aux
Consequently, methane is continuously passed
from conduit 5I through conduit 6l to reforming
iliary equipment combined therewith known to
unit 63 and steam from conduit 62 is admixed
those skilled in the art. Synthesis reaction unit
with the methane stream in reforming unit 63
59 may comprise a plurality of reactors in series 20 to eifect the reaction between steam and meth
or in parallel. The reaction conditions of op
ane to produce hydrogen and carbon monoxide.
eration will depend upon the product desired
The operation of reforming unit 63 is similar to
and upon the particular catalyst used and will
the operation of reforming unit I 4 of Figure 1
usually be within the aforesaid conditions of
and, therefore, the operating conditions, the con
operation with respect to synthesis unit 2| of 25 struction of the reforming unit and the manner
Figure 1, except with regard to changes neces
of op-eration need not be discussed in detail here.
sitated by the change in composition of the syn
The reforming operation is effected at a tem
thesis feed. Since the reaction eiiiuent has a
perature between about 1400o F. and about 1600"
relatively low ratio of hydrogen to carbon mon
F. in the presence of a catalyst by the indirect
oxide therein, the most suitable catalyst for such
heating of the methane-steam mixture in tubes
low ratios is iron and thus this catalyst is pre
of a conventional reforming furnace 63. A reac
ferred. However, other conventional synthesis
tion eiliuent comprisingv hydrogen and carbon
catalysts, such as cobalt or nickel, may be used
monoxide in a mol ratio greater than about 2:1
in synthesis unit 59 without departing from the
is removed from reforming unit 63 through con
35 duit Si and ispassed through a cooler 66 in
scope of this invention.
Synthesis unit 59 comprises, in addition to a
which steam is condensed from the eii‘luent and
reactor, suitable condensation and separation
removed therefrom through conduit 61. The re
equipment for separating normally gaseous com
action eñiuent is cooled by cooler 66 to a tem
ponents, such as unreacted reactants, and nor
perature below about 100° F. From cooler 86 the
40
mally liquid products of the process from the
cooled effluent is passed, with or without com
l,
reaction eiiiuent as shown in Figure 1 and pre
pression and/ or preheating (not shown), through
viously described. A gaseous mixture comprising
unreacted hydrogen and/or carbon monoxide,
conduit 68 to a conventional synthesis reaction
unit 69 comprising either a conventional ñxed or
carbon dioxide and methane, is removed from
unit 59 through conduit 'Il corresponding to
ñuid bed reactor, suitable auxiliary equipment
and conventional condensation and accumulating
units for the separation of products of reaction
and normally gaseous components of the effluent.
The catalyst in synthesis reaction unit 69 may be
oxide, usually below about 2:1, the reaction efflu
any of the various conventional hydrogenating
ent will contain a relatively small proportion of 50 catalysts for the production of hydrocarbons and
hydrogen and will be rich in carbon dioxide, espe
oxygenated organic compounds, >such as iron,
cially when an iron catalyst is used. An analysis
cobalt and nickel. 'Fnesynthesis reaction con
of a typical recycle gas in conduit 'H is Yshown in
ditions are substantially the same as those de
Table V below:
,
'
scribed with respect to synthesis reactor 2l of
'Figure 1 and synthesis unit 59.1 of Figure 2.
Table V
Since the synthesis feed comprises hydrogen and
Mol per cent
carbon monoxide at a ratio greater than about
N2 _____» _______________________________ __
3.3
2:1, a conventional and suitable catalyst in this
H2 ____________________________________ __. 28.1
step comprises cobalt. A cobalt catalyst may
COI ___________________________________ __ 11.4
60 be advantageously employed in synthesis unit 69
CO2 _____________________________ _.;_____ 47.6
either conduit 24 or 33 of Figure 1. Since the
synthesis feed to the synthesis unit 59 has a rel
atively low mol ratio of hydrogen to carbon mon
CH4
__________________________________ __
6.1
C‘z-I-
__________________________________ __
3.5
Such a composition of recycle gas of course de
pends on such operating conditions of synthesis
unit 59, as temperature, pressure, catalyst, space
velocity, composition of feed gas, etc. According
to this modiñcation, the gases are passed through
because cobalt is characterized for its use with
a molar feed ratio of hydrogen to carbon mon
oxide between about 2:1 to 3:1. An iron cata
' lyst, particularly a low alkali iron catalyst, can
be used and is preferable in some instances.
Since reforming unit 53 is operated at rela
tively low pressures below about 100 pounds per
square inch gag-e, synthesis unit 59 can be oper
ated at relatively low pressures and may be oper
conduit 'H and 6| to a reforming unit 63 in a
similar manner and for similar reasons as de 70 ated at pressures as low as 100 pounds per square
scribed with regard to the recycling of a high
inch gage or lower, especially when using a. co
carbon dioxide content recycle gas to reforming
unit I4 of Figure l. It is desirable in this par
ticular instance when there is a relatively low
concentration of hydrogen and carbon monoxide 75
balt catalyst. The operation of unit 69 at low
pressures eliminates the necessity of compressing
the effluent from reforming unit 53. Neverthe
less, synthesis unit may be operated at pressures
2,683,152
12
as high as 500 pounds per square inch gage With
production in unit t9 results in a Well-balanced
out departing from the scope of this invention.
Recycle gases are withdrawn from synthesis
unit @il through conduit ‘E2 which corresponds
to either conduit il@ or conduit ¿'33 of Figure l.
Recycle gases from synthesis unit SS. contain a
relatively high concentration of hydrogen and a
relatively low concentration of carbon dioxide be
cause the original synthesis feed to that unit con
tains a relatively high ratio of hydrogen to car
leon monoxide. A typical recycle gas »composi
tion passing through conduit 'l2 is shown in Table
VI below which composition depends upon the
process since it provides a. source ofv gasoline and
chemicals from a single integrated process.
operating conditions existing in synthesis unit 69.
Table VI
Mol per cent
____________________ __
2.7
Another single integrated process for the pro
duction of gasoline and diesel fuel is provided by
the present invention when a low alkali iron cata
lyst is used in the low ratio HzzCO unit 59 and
a cobalt catalyst is used in the high ratio I-IstCO
unit ‘53. The low alkali iron catalyst produces a
high yield of gasoline motor fuel and the cobalt
catalyst produces a high yield of diesel fuel. Of
course,r various operating conditions character
istie for each catalyst andr product, which are
known to those skilled in the art, may be em
ployed.
It is within the scope of this invention to re
cycle a portion of the recycle gases directly to
the synthesis reaction zones of Figure 2. Recycle
gases in conduit 'il may be dividedand a portion
passed directly to synthesis unit 59, the recycle
gases being prepared by any of the methods de
scribed vvith regard to Figure 1. Additionally or
alternatively to the above, a portion of the re
cycle gases in conduit 'l2 can be recycled directly
Total _________________________ __ 100.0 25 to synthesis unity 59.
` Certain valves, coolers. heaters, accumulators,
Since- the recycle gases in conduit 'l2 have
distillation columns, pumps, etc. have been omit
such a composition, it is very desirable on account
ted from the drawings as a matter of convenience
of their high pressure and the presence of hy
and their use and location will become obvious
drogen and methane to recycle these gases to
to those skilled in the art. The. length of cer
combustion unit 53 through conduits ‘l2 and 52 30 tain conduits of Figures l and 2 of the drawing
as previously described with regard to Figure l.
are not proportional to the distance travelled but
The presence of hydrogen in combustion unit 53
are merely diagrammatical. It is not intended
shifts the production» of carbon dioxide to the
to limit any particular location of inlets and out
production of carbon monoxide and results in a
lets as shown in the drawings. The examples of
greater Volume of hydrogen in the reaction
composition of gases and theory in connection
eiiluent from combustion unit
Products of
with this invention are offered as illustration and
the process are Withdrawn from synthesis unit
should not be construed to be unnecessarily
S9 through- conduit ‘le and are combined with the
limiting to the invention.
products of the process in conduit ‘i3 and are
Various modiñcations- and alterations of the
passed through conduit i8 to conventional puri
present invention may become apparent to those
ñcation and recovery units (not shown) .
skilled in the art Without departing from the
In the event synthesis unit 59 is operated at
scope of this invention. For example, conversion
a pressure below the pressure existing in com
bustion unit 53, a compressor (not shown) is pro
vided inv conduit l2 for compressing the recycle
gases to the inlet pressure of combustion unit 53.
Compression of the gases in conduit 'l2 instead of
in conduit E?, reduces the compression costs be
cause the quantity of gases to be compressed is
less.
A portion of the recycled gases in conduits 'il
and i2 may be vented through conduits l'i and/or
18, in order to prevent the build-up of inert gases,
such as nitrogen, in thev system. The gases. from
conduits 'il' and lli
be vented to the atmos
phere or used as fuel, or passed through a car»
bon dioxide absorption unitsimilar torunit
of
Figure l,
the carbon dioxide recovered and
recycled to either or both of conduits 'il and '52,
preferably to conduit ll;
Since relatively low ratios of HzzCo are con
ducive to CO2 formation rather than water for
mation,.synthesis unit 5t of Figure 2 can be con
veniently operated with a high alkali iron cata
lyst (1.0 to 2.0% alkali) to produce Water soluble
oxygenated organic compounds, such as alcohols,
acids, etc. The small quantity of water produced
decreases the cost of recovery of
Water solu
ble chemicals from the Water. ln combination
with the prod .ction of oxygenated compounds in
synthesis unit
unit
is advantageously oper
ated to produce the maximum yield of hydro
carbons, such as by use of a low alkali iron cata
lyst or a cobalt catalyst. The combination of
chemical production in unit 59 and hydrocarbon
of coal or coke Withsteam andv »oxygen may he
substituted for the partial combustion` of meth
ane in unit
to produce a synthesis feed gas of
a relatively low ratio of hydrogen to carbon mon
oxide. Moreover, it may be necessary to remove
HzS from the feed stream in conduit 5l when
the feed is natural' gasV in order to prevent in
jury to the catalysts and'equipment.
I claim:
1. A process for the. preparation of a hydro
carbon synthesis feed gas which comprises intro
ducing a normally gaseous hydrocarbon from an
external source into separatereforming and com
loustiony zones arranged in parallel; reacting the
hydrocarbon with steam in the reforming zone
under reforming conditions to produce a gaseous
effluent comprising hydrogen and carbon mon
oxide in a relatively high mol ratio; simultane
ously reacting in the combustion zone under par
tial coinbustion conditions free oxygen, the hy
drocarbon and a recycle product stream contain
ing hydrogen and methane of an effluent from a
synthesis reaction for the production of hydro
carbons from carbon monoxide and hydrogen to
produce a gaseous edluent comprising- hydrogen
and carbon monoxide in a relatively low mol
ratio, and combining the eiiiuents from the re
forming and combustion zones to produce a syn
thesis feed gas of the desired hydrogen-carbon
monoxide mol ratio.
2. A process for the preparation of a hydro
carbon synthesis feed gas which comprises in
...i
2,683,152
13
troducing a normally gaseous hydrocarbon from
an external source into separate reforming and
14
carbon synthesis feed gas which comprises in
troducing a normally gaseous hydrocarbon from
an external source into separate reforming and
combustion zonesA arranged in parallel; reacting
steam with said gaseous hydrocarbon in the re
forming zone at a temperature between about
combustion zones arranged in parallel; reacting
the hydrocarbon with steam in the reforming
zone under reforming conditions to produce a
gaseous eiiiuent comprising hydrogen and carbon
monoxide in a mol ratio greater than about 2:1;
Í1250 and about 2400 degrees Fahrenheit, under
simultaneously reacting in the combustion Zone
a pressure between atmospheric and about 100
under partial combustion conditions free oxygen,
pounds per square inch gage to produce a gaseous
the hydrocarbon and a recycle product stream 10 eiiiuent comprising hydrogen and carbon monox
containing hydrogen and methane of an effluent
ide in a mol ratio greater than about 2:1; simul
from a synthesis reaction for the production of
taneously reacting in the combustion zone under
hydrocarbons from carbon monoxide and hydro
partial combustion conditions at a temperature
gen to produce a gaseous effluent comprising hy
between about 1700 and about 2600 degrees
drogen and carbon monoxide in a mol ratio less
than about 2:1, and combining- the eiiluents from
the reforming and combustion zones to produce
a synthesis feed gas of 'the desired hydrogen-car
bon monoxide mol ratio.
3. A process for the preparation of a hydro
carbon synthesis feed gas Which comprises in
troducing a normally gaseous hydrocarbon from
Fahren-heit and a pressure between atmospheric
and about 500 pounds per square inch gage free
oxygen, said gaseous hydrocarbon and a recycle
product
stream
containing
hydrogen
and
methane of an effluent from a cobalt-catalyzed
synthesis reaction for the production of hydro
carbons from carbon monoxide and hydrogen
to produce a gaseous eii‘iuent comprising hydro
gen and carbon monoxide in a mol ratio less
than about 2:1, and combining the eiiiuents of
the reforming and combustion zones to produce
a synthesis feed gas of the desired hydrogen
reforming conditions to produce a gaseous efîiu
carbon monoxide mol ratio.
ent comprising hydrogen and carbon monoxide
7. A process according to claim 4 in which
in a mol ratio greater than about 2:1; simul
said recycle product stream comprises in addi
taneously reacting at relatively high pressure 30 tion
carbon dioxide separated from the eiiiuent
under partial combustion conditions in the com
of a synthesis reaction for the production of
bustion zone free oxygen, said gaseous hydro
hydrocarbons from carbon monoxide and hy
carbon and a recycle product stream containing
drogen.
hydrogen and methane of an effluent from a
8. A process for the preparation of a hydro
an external source into separate reforming and
combustion zones arranged in parallel; reacting
steam with said gaseous hydrocarbon in the re
forming zone at a relatively low pressure under
cobalt-catalyzed synthesis reactionfor the pro
duction of hydrocarbons from carbon monoxide
carbon synthesis feed gas which comprises in
troducing a normally gaseous hydrocarbon from
and hydrogen to produce a gaseous eiiìuent com
an external source into separate reforming and
prising hydrogen and carbon monoxide in a mol
combustion zones arranged in parallel; reacting
ratio less than about 2:1, and combining the
steam with said gaseous hydrocarbon in the
eíiiuents of the reforming and combustion zones 40 reforming zone at a temperature between about
to produce a synthesis feed gas of the desired
1250 and about 2400 degrees Fahrenheit, under
hydrogen-carbon monoxide mol ratio.
a pressure between atmospheric and about 100
4.'A process for the preparation of a hydro
carbon synthesis feed gas which comprises in
troducing a normally gaseous hydrocarbon from
an external source into separate reforming and
combustion zones arranged in parallel; reacting
steam with said gaseous hydrocarbon in the re
forming zone at a temperature between about
1250 and about 2400 degrees Fahrenheit, under i
a pressure between atmospheric and about 100
pounds per square inch gage to produce a gase
ous eii‘iuent comprising hydrogen and carbon
monoxide in a mol ratio greater than about 2: 1;
pounds per square inch gage to produce a gaseous
effluent comprising hydrogen and carbon monox
ide in a mol ratio greater than about 2:1; simul
taneously reacting in the combustion zone under
partial combustion conditions at a temperature
between about 1700 and about 2500 degrees
Fahrenheit and a pressure between atmos
pheric and about 500 pounds per square
inch gage free oxygen, said gaseous hydro
carbon and a recycle product stream con
taining hydrogen and methane of an effluent
from a synthesis reaction for the production of
simultaneously reacting in the combustion zone 55 hydrocarbons from carbon monoxide and hydro
under partial combustion conditions at a temper
gen from which water and organic compounds
ature between about 1700 and about 2600 degrees
having a C3 and higher carbon content have
Fahrenheit and a pressure between atmospheric
been removed to produce a gaseous effluent com
`and about 500 pounds per square inch gage free
oxygen, said gaseous hydrocarbon and a recycle 60 prising hydrogen and carbon monoxide in a mol
ratio less than about 2:1, and combining the
product stream containing hydrogen and meth
eiiìuents of the reforming and combustion zones
ane of an eiiiuent from a synthesis reaction
to produce a synthesis feed gas of the desired hy
for the production of hydrocarbons from carbon
drogen-carbon monoxide mol ratio.
monoxide and hydrogen to produce a gaseous
eíiiuent comprising hydrogen and carbon monox 65
References Cited in the file of this patent
ide in a mol ratio less than about 2:1, and com~
UNITED STATES PATENTS
bining the effluents of the reforming and com
bustion zones to produce a synthesis feed gas
Number
Name
Date
oi' the desired hydrogen-carbon monoxide mol
ratio.
70
5. A process according to claim 4 in which the
normally gaseous hydrocarbon is methane.
6. A process for the preparation of a hydro»
2,185,989
Roberts, Jr _______ -_ Aug. 19, 1938
2,270,897
Roberts, Jr., et al. __ Jan. 27, 1942
2,274,064
2,324,172
Howard et al _____ -_ Feb. 24, 1942
Parkhurst ______ __ July 13, 1943
2,541,657
Lynch -,.,...-..-_„...._ Feb. 13, 1951