Note: Descriptions are shown in the official language in which they were submitted.
47~L
This invention relates to a continuous l~rocess for
the prc)duction of uel gclS or synthesis gas by the partial
oxida~ion of a l~yclrocarbonaceous fuel More specifically,
the present invclltion relates to an iml)ro~ed procedure for
producing cooJc~l and cleaned gas mixturcs comprising hydrogen
and carbon loonoxide.
Liquill hy(lrocarl)orl fuels have previously l~een
partially o~idized with oxygen in the presence of stearn to
produce a mixture of gaseous products comprising carbon
monoxide and hydrogen. See, fo~ exampleJ U.S. Patent
No. 2,809,104, where the effluent gas stream from the reaction
zone is cooled by quenching in water. Scrubbing a precooled
gas stream with an oil-water emulsion containing ;-lbout 10 to 90
volume % water is described in U. S. Patent No. 3, 010, 8]3.
By quenching the effluent gas stream in water or in
emulsions containing large amounts of water, large amounts of
I2O will be introduced into the gas stream, and may be costly
to remove. Moreover, dispersions of particulate carbon and
watcr a-re produced, and complex systems are required to
:~0 separate the carbon from the water.
; By the present invention, traditional costly carbon
removal system~ may be eliminated and the waste water
treatment facilities now required to meet water disposal
standard~ may be simplified.
The present invention provides a process for the
production of clean synthesis gas or fuel gas which comprises:
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- _ 2 -
: . . .: -: : ~ . . , : .
~L~8~'74 "
(a) partial oxidation o~ a ~eed comprising dispersion of par~iculate
carbon in a liquid hydrocarbonaceous fuel with a free oxygen-con-
taining gas in a free flow, unpacked gas generator, at a tempera-
ture of from about 1300 to 3000F., and a pressure of from about 1
to 250 atmospheres, to produce an effluent gas stream comprising
H2, C0, CO2, H2O and entrained particulate carbon;
(b) cooling the effluent gas stream in a quench zone to a temperature
of from about 300 to 900F., but above the dew point of water in
~he effluent gas stream, and simultaneously removing the entrained
particulate carbonJ by discharging the effluent gas stream directly
into a body of hot immersion fluid comprising a dispersion of par-
~ ticulate carbon in hot liquid hydrocarbonaceous ~uel, and recover-
ing a clean gaseous stream comprising H2, CO, CO2, and H20;
~c) cooling at least a portion of the hot immersion fluid to a tempera-
ture of from about 300 to 850F., by indirect heat exchange, and
recycling at least a portion of the resulting cooled immersion
fluid to the quench zone; and
(d) introducing a portion of the hot immersion fluid produced in step
~b) or a portion of the cooled immersion fluid into the gas gener-
ator as at least a portion of the feed.
In accordance with one preferred embodiment, the
-- 3 --
partial oxidation is carried out in the presence of a -temperature
moderator, for example H20, C02, flue gas, cooled and recycled
effluent gas from the gas generator, or a mixture thereof.
Preferably, the temperature moderator and liquid
hydrocarbonaceous fuel are employed in a weight ratio of up to
3Ø
In accordance with another embodiment of the invention~
the clean gaseous stream is further purified by scrubbing in a
scrubber with a scrubbing fluid comprising liquid hydro-
carbonaceous fuel; an effluent stream from the scrubber isintroduced into a gas liquid separator; clean product gas and a
separate stream of scrubblng fluid are removed from -the
separator; a first portion of the scrubbing fluid is recycled
to the scrubbi~g zone; a second portion of the scrubbing fluid
is mixed with a portion of immersion fluid being recycled; and
additional liquid hydrocarbonaceous fuel is introduced into the
s-eparator, or into a ~tream of scrubbing fluid from the
separator.
In accordance with an alternative embodiment of the
invention, the clean gaseous stream is ~urther pur~fied by
scrubbing in a scrubber with a scrubbing ~luid comprising wa-ter;
an effluent stream from the scrubber is introduced into a gas-
liquid separator; by-product water, and clean product gas are
recovered from the separator and separate por-tions of by-product
water are recycled to the gas generator as temperature
moderator, and to the scrubber as scrubbing fluid. In this
embodiment, make up water is advantageously ineorporated
in recycled wa-ter from the separa-tor.
When a scrubber is employed, effluent from the
scrubber can, if desir~ed, be cooled before i-t is passed to the
separator.
Cl ~ C10 hydrocarbon vapors may be obtained as a
result of thermal cracking or volatilization of a portion of -the
immersion fluid during quenching of the hot process gas stream in
the quench zone. C5 - C10 hydrocarbon vapors that may be
entrained in the product gas stream may be condensed by
cooling and thereby separated from the prdduct gas stream.
By -the process of -the present invention, cooled and
cleaned synthesis gas or fuel gas may be produced.
The gas generator for carrying out -the partial
oxidation reaction preferably consists of a compact, unpacked,
free-flow, noncatalytic, refractory-lined steel pressure vessel
of the ~ype described in U.S. Patent No. 2809,104.
The ratio of free-oxygen in the free-oxygen-containing
gas, to carbon in the feedstock (OtC atom/atom) is generally in
the range of abou-t 0.6 to 1.5. Substantially pure oxygen is
preferred to minimize introducing nitrogen and other gaseous
impurities into the product gas.
The term "liquid hydrocarbonaceous fuel" as used
herein is intended to mean by definition a liquid material
containing carbon and hydrogen, and optionally other elements.
Examples include petroleum distillates and residual, gas oil,
: . :
.: ::: ~ :; . ; ;
. : .. ~ - . . ~ .
:
residual fuel, reduced crude, whole crude, asphalt, coal tar,
coal oil, shale oil, tar sand oil, and mixtures thereof.
Thermally cracked and vaporized constituents thereof which are
normally liquid C5 - C10 hydrocarbons are lso by definition
"liquid hydrocarbonaceous fuels". An economic advantage is
obtained whenilow cost sulfur-containlng petroleum oils with a
sulfur content in the range of abou-t 1 to 7 weight % are used.
Pumpable slurries of solid carbonaceous fu~ls, e.g.
particulate carbon, petroleum coke, and mixtures thereo* in a
liquid hydrocarbonaceous fuel~ such as one previously listed,
may also be fed to the gas generator and are included within
the definition of liquid hydrocarbonaceousf~uel. ~`
The liquid hydrocarbon ceous fuel may preferably
be introduced into the gas generator in liquid phase at a
temperature in the range of ambient to below the vaporæzation
temperature. Alternatively, the hydrocarbonaceous fuel feed
may be atomized and dispersed in steam or some other
temperature moderator.
Typical effluent gas streams f~m the gas generator
may have the following composition in mole %: H2 10 to 60;
C0 10 to 70; C02 1 to 50; H20 2 to 50; CI14 nil to 30;
N nil to 75; H2S nil to 2.0; COS nil to 0.7; r nil to 2;
and may contain from 0.2 to 20 weight ~ of particulate carbon
(basis weight of C in the hydrocarbonaceous fuel).
The effluent gas stream leaving the gas generator is
passed directly into a relatively large body of pumpable
-6-
.. . :. : : . '....... -
immersion fluid contained in a cooling and cleaning zone in an
oil immersion tank or quench tank. The immersion fluid
comprises a liquid hydrocarbonaceous fuel and may con-tain
dispersed particulate carbon.
In a preferred embodiment the effluent gas stream
from the gas generator is introduced below the surface of a
pool of liquid hyd~ocarbonaceous fuel-particulate carbon
dispersion contained in an immersion or quench tank,
preferably a vertical tank with an axially disposed dip leg.
The gas stream is passed through the dip leg and is discharged
beneath the surface of a pool of the liquid hydrocarbonaceous
fuel contained in the steel pressure vessel. A concentric
draft tube, open at both ends, may surround the dip leg,
leaving an annular passage -therebe-tween. In operation, the
direction of the down-flowing gas stream may thereby be reversed
and a mixture of gas and cooling fluid may then pass up through
the liquid hydrocarbon. The gas then separates in the space
above -the surface level of the immersion fluid, near the top
of the oil immersion tank. Generally, about 30 to 60 gallons
of immersion fluid are contained in the immersion tank for each
1000 Standard Cubic Feet of effluent gas from the gas generator
that is quenched therein.
The turbulent conditions in the oil immersion tank,
caused by the large volumes of gases bubbling up through the
; annular space, help the immersion fluid to scrub substantially
all the solids from the effluent gas, forming a dispersion of
unconverted par-ticulate carbon and immersion fluid. Thus
as used herein, the term "immersion fluid" is intended -to
mean either the mixtures of liquid hydrocarbonaceous fuels or
a pumpable dispersion of liquid hydrocarbonaceous fuels and
particulate carbon. The solids content of this oil - carbon
pumpable dispersion is generally in the range of about nil
to 50.0 % by weight, preferably from about 2.0 -to 8.0% by
weight.
The cooled clean process gas stream ~eaving the
imm~rsion fluid has an exit temperature in the range of about
300 to 900F., and preferably a temperature in the range of
about 600 to 700F. The lower temperature should be above
the dew point of wa-ter to prevent water from condensing out of
the process gas stream. The time in the immersion zone is
generally about 5 to 60 seconds. The effluent gas stream
leaving the immersion zone comprises H2, CO, CO2, and H2O,
and optionally contains at least one ma-terial from the group
H2S, COS, N2 r, par-ticulate carbon, and Cl - C
hydrocarbons. There may be up to 40 mole % of Cl - C10
hydrocarbons, which may result from thermal cracking or
volatilization of the immersion fluid.
The immersion f~uid may be maintained at a
temperature in the range of about 300 to 850~)F., and preferably
about 600 to 750F. The pressure in the i.mmersion tank is
generally in the range of about 1 - 250 atmospheres and is
"~.
preferably ~he same as in the gas generator. A pressure in
`~
~ -8-
~.
.. ..
. . .
~8ig~47~ ~
. .
tl-le range of al)o~1t ~3 to 250 atn1os~ eI~cs is suital)le. ~ c
it is desirat)l,e to minimize volatilization of the imn ersion
fluicl, higher pressures may be used, e. g. 1500 psia or
more~ To minimize Cl - C4 hydrocarbons in tl1e product
gas, the upper temperature of the immersion fluid should be
kept below its thermal cracking temperature. Optionally,
a r)ortion of the hot immersion fluid m.~y be removed from the
immersion tanlc at a temperature in the range of about 300
to 850 F., and m~y ~e introduced into the gas generator at
substantially the same temperature, as feed thereto. In
this mcmner the immersion tank serves as a fuel preheater
The liquid hydrocarbon immersion fluid is pumpable
at the operating conditions existing in the quench tank. The
liquid hydrocarbonaceous fuels which were previously described
as feedstock for the gas generator, and the immersion fluid are
substantia~y the same type of materials.
The temperature of the immersion fluid may be
controlled by continuously removing at least a portion of the hot
immersion fluid from the immersion tankJ cooling it, and
recycling to the immersion tank at least a portion of sa1d cooled
irnmersion fluid, optionally in admixture with a liquid dispersion
coml~rising particulate carbon, make~up liquid hydrocarbonaceous
fuel, and any condensed C5 - Cl0 hydrocarbons. This liquid
.~ . ,
dispersion may be obtained from subsequent gas scrubbing
and gas liquid, separation steps. Optionally, a portion of the
cooled immersion fluid may be recycled to the gas generator as
, .
_ g _ :
feed. Optionally, a portion of the immersion fluid may be
removed rom the system and burned elsewhere as fuel.
Cooling of the hot immersion fluid that is removed
from the immersion tank may be effected in a heat exchange
zone by indirect heat exchange with a coolant in a cooler, or
alternatively in a steam generator, producing by-product
ste~m and cooled immersion fluid.
At start-up, the immersion fluid may have to be
heated by conventional means -to a temperature that is above
the dew point for H2O in the effluent gas stream from the gas
generator.
The cleaned and cooled process gas stream ~eaving
from the -top of the oil immersion tank has a temperature in the ;~
range of about 300 to 900F., and preferably about 600 to 750F.
Residual solids contained in the gas stream may be removed by
passing the gas stream through a nozzle scrubber. A
conventional orifice or venturi scrubber may alternatively be
employed. For example, the process gas stream may be
passed through the throat of a nozzle-type scrubber at a velocity
in the range of about 100 - 400 feet per second. About 5 to 10
gallons of scrubbing fluid per 1,000 standard cubic feet are
injected into the process gas s-tream a-t the throat of -the scrubbing
nozzle.
In a first embodiment of the subject process, the
pumpable scrubbing fluid comprises liquid hydrocarbonaceous
~` fuel, optionally containing particulate carbon, and any condensed
:
-10-
~OB~47~
ligllt liquid hydrocarbons in the range C5 - C10 that n-~ay be
preserlt.
In t~le Eirst cmbodiment, the product gas leaving the
gas-liquid separcltor may contain from about nil to 40 mole
percent of Cl ~ C10 saturated and unsaturated hydrocarbons due
to cracking or vaporization of the immersion fluid. Other ;~
gaseous constituents incl-lde II2, CO, C02, and optionally
gaseous impurities selected from the group ~I2O, N2, ~r,
H2$, COS, and mixtures thereof. For example, synthesis
0 g.lS product may preferably contain up to 5 mole % Cl - C10
hydrocarbons, while fuel gas may preierably contain from 10
to 40 mole % of Cl - C10 hydrocarbons. The greater the
amount of Cl - C10 hydrocarbons present, the higher the heating
value of the product gas. Thus, for the same oxygen
consumption in the gas generator, fuel gas may be produced by
i
the process according to the present invention, having a greater
heating value, e. g. from 400 to 800. I3. T, IJ. per standard
cubic feet (SCF).
The amount of Cl - C10 hydrocarbons in the product gas
is a function of the characteristics of the immersion fluid, and the
temperature of the immersion fluid. Thermal cracking of the
-~ immersion fluid should be controlled or minimized when
synthesis ga,s is produced. In such case refractory oils such
as residual aromatic oils, high flow rates, low quench
temperatures, preferably below the thermal cracking temperature,
i, e. 300 to 500F., and pressures of at least 1500 psia are
. ~ : . . .
preferred operating condi-tions for producing a product gas
containing up to 5 mole % Cl - C hydrocarbons
However, when the product gas is fuel gas, some thermal
cracking of the immersion fluid in the immersion zone is
preferred, to increase the heating value of the gas.
If desired~ additional conven-tional gas purification
steps such as solvent absorp-tîon or cryogenic cooling may be
employed to eliminate any or all of the gaseous impuri-ties
from the product gas stream. For example, the product
gas leaving the gas-liquid separator may be cooled to condense
out water or a mixture of water and at least part of the C5 - C10
hydrocarbons.
In a second embodiment oE the process according to the
present invention, cleaned and cooled process gas stream
leaving from the top of the oil immersion tank is scrubbed fur-ther
in a scrubber, pre~erably a nozzle scrubber, with a pumpable
scrubbing fluid comprising by-product water collected -
subsequently in the process in admixture with fresh make-up
water. The process gas stream is then cooled below the
~` 20 dew points of the H20 and any normally liquid light hydrocarbons,
i.e. C5 - C10 that may be contained thereîn.
In a gas-liquid separator, the product gas from this
second embodiment may be separa-ted from the normally liquid
constituents, i.e. water and C5 - C10 hydrocarbons present in
the scrubbed gas stream. Any C5 - C10 liquid hydrocarbons
present will form a dispersion with the particulate carbon
-12-
~ 8~7~ ~
scr~lbbecl fl~onl t~le ~clS stl~ea~ lC (~ sl)cr,si~ ;el)al~ales
out an(l floats on the by-product water layer that sinlcs to the
bottom of the gas~liquid separator. If there is only a small
quantity of C5 - C10 liq~ hydrocarbons present, or if there
are no such hydrocarbons, the particulate carbon will form a
dispersion with the by-product water.
Before leaving the gas~ uid separator, the process
gas stream is was}led with clean n~ake-up water. The clean
product gas leaving the gas-liquid separator may then contain
from about nil to a~0 mole % of Cl - C4 saturated and unsaturated
normally gaseous hydrocarbons, produced by thermal cracking
of the immersion fluid. Other gaseous constituents include ~I2,
CO, CO2, and optionally gaseous inlpurities selected frorn the
group N2, Ar, ~12S, COS, and mixtures thereof. For example,
syn-thesis gas product m.ly preferably contain rom about nil
to 5 nJole ~0 of Cl ~ C4 hydrocarbons, while fuel gas may
preferably contain from 10 to 40 mole % of Cl - C4 hydrocarbons.
-~ The greater the amount of Cl - C4 hydrocarbons present, the
higher the heating value of the product gas Thus, for the
same o~cygen consumption in the gas generator, fuel ~as may be
produced by the subject process having a greater heating value
e, g. about d,00 to 800 B. T, U, per standard cubic foot (SCF).
The amount of Cl - C4 hydrocarbons in the product
gas is a f~nction of the characteristics of the immersion fluid,
and the temperature of immersion fluid. If desired,
dditional conventional gas purification steps such as by solvent
- 13 -
absorption or cryogenic cooling may be employed to elimmnate
any or all oE the gaseous impurities from the produc-t gas
stream.
In this second embodiment, the by-product water in
liquid phase separates by gravity from the product gas and ;~
any C5 - C10 liquid hydrocarbons in the gas-liquid separator.
A first portion of the by-product water in admixture wlth
make-up water is recycled to the nozzle scrubber as scrubbing
fluid, and a second portion is consumed in the gas generator
as a temper~ture moderator, as previously described.
Optionally, a third portion may be removed and used elsewhere
in the system. Any C5 - C1O liquid hydrocarbons separated
in the gas-liquid separator may be consumed in the gas ;
generator as a portion of the feed.
Advantages of the process according to the present
invention, include: (1) elimination of the conventional carbon-
extraction step employing naphtha for extracting carbon from
carbon-water slurries followed by decan-ting and naphtha
stripping; (2) production of synthesis gas or enrlched fuel
, .
gas having a high B.T.U. per SCF; and ~3) increased thermal
efficiency, by employing heat from the effluent gas from the gas
generator to preheat the oil feed to the gas generator.
A more complete understanding of the invention may
be had by reference to F~gs 1 and 2 of the accompanying Drawings
which show in detail, two embodiments of the process according
to the present invention. Quantities have been assigned to
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. :,~ . .. . . .
various streams so that -the following descrip-tion in
Examples 1 and II may also serve as an example of the subject
inven-tion.
E AMPLE I
This employs the apparatus shown schematically in
Fig. 1 of the accompanying Drawings.
On an hourly basis, about 2000 lbs. of an oil-carbon
feed dispersion in line 1 at a tempera-ture oP about 300F. is
passed through inlet 2 and inner annulus passage 3 of burner 4.
Simultaneously, about 1200 lbs. of steam at a temperature of
about 650F, in line 5 is passed through inlet 6 and outer
annulus passage 7. Burner 4 extends axially into upper
port 8 of conventional, vertical, free-flow, unpacked, non- ~;
;~ catalytic ~refractor~-lined gas generator 9. The oil-carbon
dispersion has a solids content of about 3.6 weight % of
particulate carbon. The oil in said d~spersion is 15.0 PI
California Reduced Crude having the following ultimate analysis
in wt. %: C 85.99; H 11.28; 0 0.13; N 0.88; S 1.69 and
Ash 0.03. The Heat of Com~ustion of the oil is 18,514 BTU
per lb.
Simultaneously, 2135 lbs. of substantially pure oxygen
in line 10 at a temperature of about 3000F. is passed through
central passage 15 of ~urner 4. The reactant streams
converge at the -tip of the burner where atomization of the fuel
and dispersal in the oxidant takes place.
Partial oxidation of the fuel takes place in reaction
-lS-
: - :. . . .: -
zone 16 of gas generator 9, at an au-togenous temperature of
about 2260Fo and a pressure of about 28 atmospheres.
121,700 standard cubic feet per hour (SCFH) of effluent gas
leave the gas generator by way of axially located bottom ,
flanged exit port 17 and directly passes down through dip
tube 18 and is discharged below the surface 19 of the immersion
f~uid constituted by the pool of oil-carbon dispersion 20
contained in vertical oil immersion vessel 21. Dip tube 18 ,
is axially mounted in the top flanged inlet port 22. The
direction of the process gas stream moving down dip tube 18
s reversed upon being discharged into the immersion fluid ~: :
confined in vessel 21. The gas stream then passes vigorously
~; up through the immersion fluid contained in the annular :
space 23 located between the outside surface of dip tube 18
and inside surface of open-ended concentric draft tube 24.
Spacers 25 support draft tube 24 and position it with respect to
dip tube 18. The turbulent action cools and cleans the
process gas stream, which then separates from the immersion
fluid in space 26 at the top of the immersion vessel at a
temperature of about 500F. The pressuresiin the immersion
vessel and in the gas generator are substantially the same.
Solid residues, such as ash and heavy metal
constituents, which separate from -the gas stream, sink to the :: :
bottom of the oil-carbon dispersion in vessel 21 and are
periodical~y removed through bottom axial flanged port 30, and
a conventional lock hopper system co~prising line 31, valve 32,
- :.
line 33, tank 34, line 35, valve 36 and line 37.
The temperature of the immersion fluid 20 is reduced
by removing 39,000 lbs. of the immersion fluid at a temperature
of about 500F. and containing about 4.0 wt. % of ~ar-ticulate
carbon through line 38. It is then passed through cooler 39
and lines 40-41. About 2000 lbs. of scrubbing fluid from
line 42, coming from a downstream gas scrubbing step to be
further described below, are mixed in l~ne 41 with the cooled
immersion fluid from line 40. By means of pump 43, about ;;
39,000 lbs. of this mixture of fluids at a temperature of about
300F. are pumped through lines 44 and 45 into, the top of
immersion vessel 21 as immersion fluid, About 2000 lbs. of
the mixture of fluids in line 44 are passed through line 46,
valve 47, lmne 1, and nozzle 2 into ~urner 4 as the liquid
hydrocarbonaceous fuel feed to gas generator 9. Alternatively~
coQler 39 may be placed in line 45. In such a case, a portion -
of the hot mixture of fluids in line 44 may be introduced, without
being substantially cooled, into gas generator 9 as at least a
portion of the feed, Optionally, a portion of the mixture of
fluids in line 44 may be passed through line 48, valve 49, and
line 50 and used for heating fuel.
Alternatively, the cooler 39 may be employed as a
steam generator, in order to make more efficient use of the
sensible heat of the immersion fluid.
The process gas stream is removed from space 26
at the top of immersion vessel 21 and is passed through line 55
into conventional nozzle scrubber 56 where it is scrubbed with
6200 lbs. of scrubbing fluid from lines 57 - 59. The process
gas stream, in admixture wi~h -the scrubbing fluid is then
passed through line 60 into gas-liquid separator 70 where the ,~
product gas separates, passes through a spray stream of
clean make-up California Reduced Crude Oil from line 71 at
ambient -temperature. Clean product gas is removed through
line 72 at the top of separator 70. In this example, there
are substantially no C2 - C10 hy~rocarbons in the product gas
stream. This is because the temperature of the immersion
;~ fluid in immersion vesse~ 21 is main-~ained below -the thermal
cracking temperature and below the vaporization temperature
for the existing pressure. The composition of the product
~as in line 72 in mole % (dry basis) is: H2 48.12; CO ~i4.99;
C2 5.89; CH4 0~33; H2S 0.36; COS 0.02; N2 0.22;
and Ar 0.07.
A pumpable liquid dispersion comprising scrubbing .
fluid, make-up oil, and 0.25 wt. % of particulate carbon is
removed through line 73 at the bottom of separator 70. By ~;
means o~ pump 74, a first portion is passed through lines 75
and 57 into nozzle scrubber 56. second portion is passed
through line 76 into line 42 and mixed in line 41 with the immersion
fluid from line 40, as previously described. Optionally,
further make up oil can be introduced .into line 42 through
line 77, valve 78 and line 79.
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~8~4
EXAMPLE II
This is carried out in the apparatus shown
schematically in Fig. 2 of ~he accompanying Drawings. The
same reference numerals as in Fig. 1 have been used where
appropriate. ~-
On an hourly basis about 2000 lbs. of an oil-carbon
feed dispersion in line la at a *emperature of about 300F. is
passed into line 1 where ;t is mixed with 500 lbs. of by-product
noxious water at a -temperature of about 200F. ~rom line 65.
The by~produot water acts as a temperature moderator in the
~;~ ensuing reaction. The feed mixture in line 1 is passed through ;
burner 4 by way of flanged inlet 2 and outer annulus 7. .
Burner 4 extends downwardly into upper port 8 of refraetory~
lined gas generator 9. The oil-carbon dispersion has a `
solids content of about 3.6 weight % of particulate carbon.
Theooil in said dispersion is the same as in Example I.
Simultaneously, 2254 lbs. of substantially pure oxygen
in line 10 at a temperature of about 300F. is passed through
central passage 15 o~ burner 4. The reactant streams
converge at the tip of -the burner where atomization of the fuel
and dispersal in the oxidant takes place.
Partial oxidation of the ~uel takes place. In reaction
zone 16 of gas generator 9, at an autogenousstemperature of
about 2520F, and a pressure of about 28 atmoæpheres.
107,600 standard cubic feet per hour (SCFH) of effluent gas leave
the gas generator by way of exit port 17 and directly passes
--19--
., ' '~,
47~
down through dip tube 18 and ~as in Example I) is discharged
below the surface 19 of the pool of oil-carbon dispersion 20
contained in vertical oil immersion vessel 21. The
arrangement of the dip tube, and -the means for cooling the
immersion fluid, and for removing solid residues and cooled
product gas are substantially the same as in Fig. 1 and will
not be described in detail.
The temperature of the immersion fluid 20 is
reduced by removing about 38,500 lbs. of the immersion fluid
at a temperature of about 500F. and containing about 4.0
wt. % of particulate carbon through line 38. It is then
passed through cooler 39 and lines 40-41. About 1,950 lbs.
of fresh California Reduced Crude make-up fluid from
line 42 are mixed in line 41 with cooled immersion fluid ;
from line 40. By means of pump 43, about 38,500 lbs. of
this mixture of fluids at a temperature of about 300F. are
pumped through lines 44 and 45 into the top of immersion
vessel 21 as said immersion fluid. About 2,000 lbs. of the
mixture of fluids in line 44 are passed through line 46,
valve 47, and lines la and 1 as previously described. As in
Example I, cooler 39 may be located in line 45, so that a
portion of the hot mixture of fluid in line 44 may be intro-
duced into gas generator 9 by way of lines 46, la and 1, as
at least a portion of the feed without being substantially
cooled. By this means make-up oil may be preheated by
contact with hot immersion fluid. Optionally, a portion
of the mixture of fluids in line 44 may be
20-
passed through line ~8, valve 49, and line 50 and used as a
heating fuel.
The process gas stream is removed from space 26
at the top of immersion vessel 21 and is passed through
line 55 into conventional nozzle scrubber 56 where it is
scrubbed with -100 lbs. of by-product water scrubbing fluid ~,
from lines 57, 58~and 59 in order to remove any entrained
- particulate carbon remaining in the process gas stream.
Preferably, a portion of the by-product water may be passed
through line 63 and valve 64, and introduced into the burner
through lines 65 and 1, as previously described. The process ~;
gas stream, in admixture with the scrubbing fluid is then passed
through line 60 into cooler 61, where the temperature of the
process stream is reduced to below the condensation temperature
of wa-ter and any C5 - C10 jhydrocarbons that may be present.
From cooler 61 the process stream is passed through line 62
into gas-liquid separator 70, where the product gas separates
from the liquids present. Before leaving separator 70, the ;~
product gas receives a final scrubbing with fresh make-up water
at ambient temperature from line 71. Clean product gas is
removed through line 72 at the top o~ separator 70. In this
example there are substantially no C2 - C10 hydrocarbons in
the product gas s-tream~ This is because the temper~ture
of the immersion fluid in immersion vessel 21 is maintained
below the thermal cracking temperature and below the
vaporization temperature for the existing pressure. The
-21-
composition of the product gas in line 72 in mole % (dry basis)
is: H2 45.14; CO 51.30; CO2 2,62; CH4 0.22;
H2S 0.38; COS 0.02; N2 0.24; and Ar 0.08.
- Optionally, the product gas in line 72 may be fuel
gas with a gross heating value in the range of about 400 to
7 00 BTU per SCF. This may be accomplished by operating
quench tank 21 at a temperature above the thermal cr~cking
temperature so that from about 10 to 40 mole % of Cl - C~ ;
gaseous hydrocarbons become mixed in the product gas.
A pumpable liquid dispersion scrubbing fluid
comprising noxious by-product wate~, in admixture with make-up
water and 0.2 wt. % of particulate carbon is removed through
line 73 at the bottom of soparator 70. By means of pump 74,
a first portion is passed through line 57 into nozzle scrubber 56.
second portion of the nozzle scrubbing fluid may be passed into
line 63, valve 64, line 65 and mixed in line 1 with the oil-carbon
dispersion from line la, as previously described. Any C5 - C10
liquid hydrocarbons may be drawn off through line 66 and burned
in the gas generator as a portion of the feed.
.:
-22-
