Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
3'~
BACKGROUND OF THE INVENTION
Field of the Invention: This invention relates to a continuous process for
the manu~facture of fuel and synthesis gas from solid carbonaceous fuels.
Description of the Prior Art: Because of increasing oil prices and decreas- -
ing supplies of natural gas, it is now necessary to use other natural fuel
resources which were previously uneconomical. While large deposits of com-
paratively low cost coal and oil shale exist in this country, these solid
carbonaceous materials may not be in a convenient form for many uses. Often
these materials contain excessive amounts of sulfur compounds which limit
their use as a fuel. In the subject improved process, slurry streams of a -
solid~carbonaceous fuels may be burned more efficiently than previously in a
synthesis gas generator.
SUM~RY
In one aspect, the present invention provides in the continuous
manufacture of gaseous mixtures principally comprising H2 and CO, and option-
ally containing at least one member of the group C02, H20, CH4, N2, A, COS~
and H2S by the partial oxidation of a hydrocarbonaceous fuel with a free-
oxygen~containing gas in the presence of a temperature moderator in a reac-
tion zone free from packing and catalyst of a free-flow gas generator, the
improvement which comprises introducing into said reaction zone a continuous
first slurry feedstream comprising a ground so]id carbonaceous fuel and a
liquid hydrocarbon fuel at a velocity in the range of about 1 to 500 feet per
second; simultaneously introducing into said reacti~n zone so as to contact
said first slurry feedstream a continuous separate second slurry feedstream
comprising a ground solid carbonaceous fuel and water at a velocity in the
range of about 1 to 500 feet per second; simultaneously introducing into said
reaction zone a continuous separate third stream comprising a free-oxygen con-
taining gas interposed between said first and second slurry feedstreams;
and contacting and mixing said three streams together to form an atomized
S~3Z~
. ~
dispersion in which the ratio of atoms of oxygen to atoms of carbon in the :
total fuel is in the range of about .6 to 1.6, the weight ratio of H20 to a
fuel is in the .range of about .10 to 1.3, and the weight ratio of total solid
carbonaceous fuel to liquid hydrocarbon fuel is in the range of about ..8 to
12, and reacting said atomized dispersion in said reaction zone at a temper- :
ature in the range of about 1500 to 3500 F., and a pressure in the range of : -
about 1 to 250 atmospheres. ~.
In another aspect the invention provides 2 process for the pro-
duction of fuel gas or synthesis gas comprising introducing into the reac-
10 tion zone free from packing and catalyst of a free-flow gas generator a con-
tinuous first slurry feedstream comprising a solid carbonaceous fuel and a
liquid~hydrocarbon fuel at a velocity :in the range of about 1 to S00 feet per . . .
second, wherein sai~ first slurry stream comprises .30 to .6S parts by weight
of a ground solid carbonaceous fuel selected from the group consisting of
petroleum coke~ coal~ particulate carbon~ coal char, coke from coal~ oil :.
shale, tar sands, pitch, and mixtures thereof for each part by weight of ~ :.
liquid hydrocarbon fuel selected from the group consisting of fuel oil,
residual fuel oil, reduced crude oil, whole crude oil, coal oil, shale oil,
gasoline, kerosene, naphtha, gas oil fractions of petroleum distillate,
benzene, toluene, hexane, heptane, cyclohexane, tetralin, decalin and mix-
tures thereof; simultaneously introducing into said reaction zone so as to
contact said first slurry feedstream a continuous separate second slurry ~.
feedstream comprising a solid carbonaceous fuel and water at a velocity in ` .
the!range of about l to 500 feet per second, and wherein said second slurry
stream comprises .3 to .65 parts by weight of said ground solid carboniferous
fuel for each part by weight of water; simultaneously introducing into said
reaction zone a continuous separate third feedstream comprising a free-oxygen
containing gas interposed between said first and second slurry feedstreams,
and contacting and mixing said three feedstreams together to fo`rm an atomized
~ - la -
j: :
~ :', ', ' . .; . : ~ ' ' ~
~ 5~?3;~:0
dispersion in which the ratio of atoms of oxygen to atoms of carbon in the
total fuel is in the range of about 0.6 to 1.6, the weight ratio of H20 to
fuel is in the range of about .10 to 1.3, and the weight ratio of total solid
.~
carbonaceous fuel to liquid hydrocarbon fuel is in the range of about 0.8 to
12, and reacting said atomized dispersion in said reaction zone at a temper- -~
ature in the range of about 1500 to 3500F.~ a pressure in the range of about
1 to 250 atmospheres, and for a residence time of 1 to 10 seconds; splitting
the effluent gaseous stream from said reaction zone into first and second
split process gas streams; cooling said first split process gas stream by
indirect heat exchange with water in a waste heat boiler to produce steam;
scrubbing with liquid hydrocarbon fuel or a dispersion of particulate carbon
and liquid hydrocarbon fuel the effluent gas stream from said waste heat
boiler to remove entrained solid particles~ separating a disperiion of par- .`
ticulate carbon and liquid h~drocarbon fuel, and separating a first product
gas stream principally comprising H2 and C0 and containing at least one
member of the group C02, H20, CH4, N2, A, COS, and H2S; mixing a portion of
said dispersion of particulate carbon and liquid hydrocarbon fuel with make-
up solid ca~boniferous fuel to produce said first slurry feedstream to the
gas~generator; separating at least one member of the group C02, H20, CH~, N2,
A~ COS, and H2S from said first product gas stream in a gas purification zone;
and simultaneously cooling and scrubbing to remove entrained solid particles
from said second split process gas stream by immersion in water in a quench
zone, removing a second product gas stream from said quench zone similar to
said first product gas stream but saturated with H2~.and substantially free
from entrained solid particles; removing a dispersion of solid particles and
water from said quench zone and separating therefrom a concentrated particu-
late carbon-water dispersion, and mixing said ground solid carbonaceous fuel
with said concentrated dispersion of particulat~ carbon-water to produce said
second slurry feedstream to the gas generator.
~ - lb -
t
3;~
.....
By the subject invention, two different and separate slurry streams .
of solid carbonaceous fuels are simultaneously brought together in a single . -
free-flow gas generator where by partial oxidation they are efficiently con- .
verted into synthesis gas or into a clean fuel gas which may be burned with-
out contaminating the environment. : - :
The two pumpable slurry reactant streams are simultaneously passed ,' -
through a double annulus type burner mounted in a gas generator. One slurry
stream comprises a solid carbonaceous fuel with water as the li~uid carrier :
and theother slurry stream comprises a solid carbonaceous fuel with a liquid
hydrooarbon fue1
.''.' . :
. "
'~'' ''~' .
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-
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.
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- as the carrier. One slurry stream is passed through the
central conduit of the bur~er while the other slurry
stre~ is passed through the outer ~nnulus o:E the burner.
Simultaneously, a reactant stream of free:-oxygen containing
gas is passed through the intermediate axl~ulus passage o~
the burner thereby flowing between the other two streams.
The three reactant stream~ are introducecL simultaneously
into the refractory lined reaction zone o~he fr~e-flo~
noncatalygic gas generator where they impinge, atomize,
and mix together. The velocity of each of the slurry streams
is in the range of about 1 to ~00 feet per second. The
velocity of the free oxygen containing gas i8 in the range
of about 100 feet per ~econd to sonic velocity.
Partial oxidation reaction takes place in the
reactlon zone o~ the gas generator at an auto~enous
temperature in the range of about 1500 to 350QF. and a
pressure ln the range of about 1 to 2~0 atmospheres. The
effluent gas leaving the gas generator is split into t~o
stream~. The ~irst split stream o~ gas is cooled in a
waste-heat boiler to produce steam. This cooled gas stream
is then scrubbed with liquid hydrocarbon fuel or optio~all~
~ater to remove entrained particulate solids. Optionally,
by convention~l gas puri~ication procedures, :acid-
gases may be removed to produce a clean dry synthesis gas or
fuel gas. The second split stream of effluent gas from the
gas gen~rator is introduced into a quench tank where it i8 ~ -:
; cooled and scrubbe~ with water. A process gas stream
3aturated with water i8 produced thereby which may be lntro-
duced into a water-gas shlft con~ers~on zone where the M2/CO
mole ratio of the g~s stream i~ increased
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By the subject invention, it was unexpectedly
found that æeadily available solid carbonaceous fuels may
be more econ~micall~ converted into a cIean fuel gas `.
having a gross heating value in the rangel o~ about 7~ to
400 ~1~ per SCF or into synthesis gas. Improved
performance may be shown by reductlon in the follo~ing
weight ratios: water to ~uel, oxygen to ~uel, and liquld
hydrocarbo~ to total solid fuel. ..
BRIEF DESCRIPTION OF T~E D~AWING .:
The invent~an ~ill be ~urther understood by
re~erence to the accompan~ing drawing in which Fig. 1
15 ~chematic repre~entation of a preferred embodiment
o~ the process.
Fig. 2 i~ a diagram~atic repreæentation in vertical cross
section o~ a preferred burner for slmultaneously intro- .
ducing the two slurry streamæ and one ~ree-oxygen containing
gaæ stream i~to the ga~ generator.
DESCRIPTION OF THE INVENTION
.
By means o~ the sub~ect proce3s, t~o gaseous
streams each comprising principally hydrogen and c&rbon
mo~oxide, and optionally at lea~t one m~mber o~ the group
carbon dioxide, water rapor~ me~hane, nitrogen, argon,
carbonyl sulfide, and hydrogen sul~ide are produced, One .~
o~ said gaseous ~treams may be æaturated with water vapor -~.
wh~l~ the other stre~m ma~ contain a ~axlmu~ of 15 mole %
O. Particulate carbon and optionally acid gas ~re
removed ~rom the gas stream~.
Th~ product gas stream m~y be considered :~uel gas
. or synthesis ga~ depending o~ the specific g~s ~pplieation.
~ypical compo~tion~ m~le ~) o~ the product gas stre~m
are sho~n in Table I.
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TABLE I
Produc Gas
H2 8.o to 60.0
co 8.o to 70.0
C2 1.0 to 50.0
H20 2.0 to 50.0
4 0.0 to 30.0
COS 0.0 to 0.7
H2S 0.0 to 1.O
N 0.0 to 8s.o
A 0.0 to 2.0
The solid carbonaceous ~uel employed in the
sub~ect process gas ~s select~d ~rom the group conslstlng
o~ coal, co~e from coal, coal char, petroleum coke~ oil
shale, tar 5ands, pitch, particulate carbon, and mixtures
thereof. With the exception of particulate carbon which
has a particle size o~ less than 10 microns, all o~ the
other solid carbonaceous fuel~ are preferably ground to a
particle size so that 100% o~ the material passes through an
ASTM E 11-70 Sie~e Designation Standard 1~25~ m (Alternative
No. 40) and at least 80~ passes through an ASTM E 11-70
Sleve De~i~nation Standard 75~U m (Alternative No. 200)
lQ00~4m - 1 mm.
The coal may be any type e.g. anthrac~te,
bitum~nous and lignite. Coke ~rom coal is the strong porous `
res~due compri3ing carbon and mineral ash formed when
coal e.e. bituminous is heated in the absence of air in
a coke oven~ Coal char may be made by the pyrolysis o~
coa~ at a temperature in the range o~ about 600 to 1600F.
with or without the presence of air, hydrogen or ~ynthe~is
gas. For ex~mple~ char may be pro~uced in a fluidizecl bed
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retort~see coassigned U.S~ Patent No. 3,715g301.
Petroleum coke consists of deh~drogenated and conden~ed
hydrocarbons of high molecular weight in the form of a
matrix o~ conslderable p~ysical extent. It princlpally
comprises carbon an~ contains dispersed throughout a ~ery -
minor amount of petroleum-based asphaltic-like compounds.
Raw petroleum coke suitable for use as a star~ing material
in the process of this invention m~y be produced by the
I'delayed coking" process or by a similar process for
converting heavy residual fuel oil into gasoline, gas oil,
and coke. A typical delaged coking process is described
in Kirk~Othmer Encyclopedia of Chemical Technology, 2nd
Edition, Vol. 15, Inter-Science Publisher 1968, pages 20-~3.
Calcined petroleum coke and ~luid coke are also suitable
as a starting material. Pitch is a black amorphous solid
or semi-solid residue obtained from the distillation of
tars and tar product~. Particulate carbon or free carbon
soot may be f~und entrained in the effluent gas stream from
.
the partial oxidation gas generator in the amount o~ about
0 to 20 weight percent (basls weight o~ carbon in the Puel).
This particulate carbon is both oleophilic and hydrophobic.
It ha6 an Oil Absorption No. o~ more than 1, and usually
one gram of particulate carbon will absorb 2-3 cc of oil. ;
Some typical solid carbonaceous ~uels are
described ~urther in Table II.
.,~
. . . ...................................................... ., : ~ ,, . . , . .. ', . ', ' ', ' ' ., ' '
33'~0
~ABLE ~I
TYPICAL SOLID CARBO~ACEOUS ~U~S
s CoaL ~oleum Particulate
CoalCoal Coke Char Coke Carbon
Proxlmate
Analysl~,
~t.~ (dry)
~olatile 38.6 2.0 3.5 5.0 3.
Matter
F~xed Carbon5000 88.o 76.4 94.3 93
Ash 11.4 10~0 20~,1 o.7 4,o
~T~S 100 . O100 . O~ 00 . O 100 0 O 100 . O
Ul~i~at2
Analy~is,
Wt.% (dry)
C 67.2 78.9 76.8 88.4 9~.2
H 5.2 7.5 1.4 7.0 1.
N 1.3 1.1 1.2 2,,1 O. 2 `
s 3.8 1.l 3.1 1.5 o,6
O 11 1 7.2 0~1 o.4
A~h 11.4 4.2 1704 oO6 2.4
TOT~LS100 . O100 . O100 . O 100 . O 100 . o
The solld carbonaceou~ fu~ls that ar~ us~d in
the sub~ec~ process arc ~ir3t ground to the prop~r 9iZ~el
and mixed ~ith a liquld vohicle to produce a pumpable
slurry. Thu~, a ~ir~t roactant ~lurry stream may comprise
solid carbonaceous ~u~l-lia,uid hydrocarbon ~u~l slurry
having a ~olids contont ln tho range of about 30 to ~:
6 5 weight p~rcent and pre~erablg about 4~ to 60 ~. %0
This ~ir~t slurry feed~kroam i~ prepared by mixing toeather
a liquid hydrocarbon ~uel with a ~olid carbonaceou~ fuel .;
solacted ~rom the group con~i~tir~ of coal, coke ~rom coal,
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coal char, fluid or delayed petroleum coke~ cal- -
Gi~ed petrol~um cok~oil sh~le~ ~a~ ~a~æ~ pl~c~
particulate carbon, and mixtures thereof. The lLquid
hydrocarbon Yuel is selected ~rom the group con~13ting
of petroleum di~tillate, gas oil~ resid~ u~1 oil~ ' -
reduced crude, whol~ crude5 a~phalt, coal tar, coal o~lg
~ha~ oil, tar ~nd oil, and m~xt~res th~r~o~. Pre~erably,
the liquld hydrocarbon ~uel i~ sc~bbing rluid w~ich was
u~ed subs2quently in the process and which contains ,.
particulate carbon ~crubbed ~rom tha e~fluent gas str~am
from the gaB generator. ;.
The ~econd r~actant slurry ~tream comprise~ a
solid carbonaceous ~uol-water pu~pable ~lurry hav~ng a :
sollds contont in the range o~ about 30 to 65 weight
p~rcent and pro~era~ly ~bout 45 to 60 wt. ~. Thi~
second slurry ~eed~tr~am i~ prepared b~ mixlng together a
~olid carbonac~ou~ fuel or ~i*tur88 thereof as previously
described with water.
The thlrd reactant stream comprises a ~ree-oxygen ~.
contalning gQ8 selected from the group consisting o~ air, ~:
oxygen-enriched alr, i.e~ at least 22 mole ~ oxygan, and
sub~tantiallg pure oxygen i.eO at lcast 95 mole ~ oxygen
(tho remainder compris~ng N2 and rare gases). Sub3tantial~y
pur~ oxygen is pre~orr~d in order to reducc tho amount of
nitrogen ~d othar gaseous impurities in the product gas.
The three reactant stre~m~ previously described ~
are introduced si~ultaneously into the reaction ~one of a
conventional free-flow gas generator pre~erably by way of
a double annulus burner. The ga~ eenerator ~s fre~ ~rom :
3 packing and catalyst. It is a vertical steel pressure
ve~cl llned on the lnside with refr~ctory, such as
, ................................ . . .
3Z~)
described in coassigne~ U~S. Patent 3~097~081. A suita~le
multiplc annulus burner is shown ln coassigned U.S.
Patent 3,705,108~ However~ the feedstream and ~elocit~es
~or the sub~ect process dlffer ~rom those dislcosed in
aaid patent.
In the sub~ct invention~ either the ~irst ox
second reactant slurry ~tream is passed into the reaction
zone by way of ~hs central nozzle o~ the triple ori~lc~
burner shown in Figure 2 o~ the drawing ~or coassigned ;~
U.S. Patent 3,705,108. Si~ultaneously, the other slurry
stream is passed through the outer coaxial annular nozzle
that iB dispo~ed about an lntermodi~te co~xial annular
nozzle which in turn is di~po~ed about said central nozzle.
The thlrd reactant ~tream compri~ine ~reo-oxygen containing
gas is passed simultaneously through said intermediate r
coaxial annular nozzle. The fir~t and second reactant
slurry str~ams ara in liquid phase at a temperature in
the range o~ about 40 to 700 F~ as they pass through the
burner at a velocity at the burner tip ln the range o~ :
about 1 ft. per 8ec . to 500 ~t. per æec. and pre~erably
about 5 to 250 ~eet per second. The thlrd ~eactant stream
comprising ~ree-o~ggen containlng gas is at a temperature
in the ranee o~ about 40 to 150~Fo as it pa~ses throug~ -
the burner at a ~elocity in the buxner tip ln the rang~ of
about 100 ft~ per secO to ~onic ~alocity and preferably
about 200-to 450 ft. p~r 8ecO By thls arrangement, the '~
free-oxygen containing gas emerge~ at the burner tip ~s
a hollo~ conical ~haped str0am which is dirscted towards
the longitudinal axls of the burn~r, and which i5 interposed
bet~n said ~irst ~nd second slurry reactant st~samO
_8_ ::
~6~5~326~
;
By this mean~ th~ free-oxygen cont~lning stream m~y deeply
penetrate the two slurry streams and provide thorough
mlxlngO The inter~ediate and out~r ann~llar channels are
inclined sligh~ly inwardly wlth respect to the longitudinal
axis o~ the burncr, making an angle in t;he range o~ about
lO to 70 degraesO Wh~n the f~r3t ~Id ~econd slurry ~.
streams impinge to~ether near the tip o~ the burner~ the
solld particles in the two stream~ eo~tact a~ch oth~r ~n~ ~re ~.
~rther-reduced i~ ~ize, The i~ermedi~e h~gh ~e-ocity
Jat ~tre~ o~ free oxy~en containing ga~ contacts the :
other two str~ams to ~orm a ~og o~ mlnuta solid particleY.
A 8ub~tantially homogeneou~ and uni~orm di~persion of ~ins
particl~s o~ 801id carbonacaou~ fuel in atomized li~uid
hydrocarbon ~uel, H20, ~nd oxygen i~ produced. By thi~ :
moan~ the combu~tlon e~iciency i8 improv~d, a~d there ma~ be a
reduotlon $n the weight ratios stoam to ~uel, oxygen to ~uel
a~d total liguid hydrocarbo~ ~uel to ~oli~ ca~bonaeeou~ fuel,
Th~ relative proportions of ~olid carbonaceous ;~
~uel, liquid hydrocarbon ~uel, water, and oxygen in the
~eed~tre~ to the gas generator are care~ully regulated
to convert a eubstantiàl portion o~ the carbon, o.g. at
least 80 wt. ~ to carbon oxid~s ~.~. C0 and C02 and to
maintain an autogenou~ reactiOn zone temperature in th0
rang~ of about 1500 to 3500F., prs~erably in tho~range o* .:.
about 1800 to 2800 Fo The pr~s~u~e in the reaction zone :
i~ in the range of 1 to 250 atmosp~ere~. The ti~0 in th~ ~:
reaction zone in s~conds i~ tho range of o.5 to ~a ~ and
pre~erably 1.0 to 10~ ~ The weight ratio o~ Bteam to
total fuol ~solid carbonaceou3 ~uel plus liquid hydrocarbon
30 - ~uel) in the roaction zone is in the range o~ about 0~1 to
_9_ :
~ ~5g3~
1.3, and preferably .2 to .50. The atomic ratio of oxygen
in the free oxygen containing gas to carbon in the total fuel
is in the range of about .6 to 1.6, and preferably o.8 to
1.4. It is co~mon practice to express ratios in this
- manner as the denominator of the ratio is one ~nd the
numerator is the range specified e.g. .6 to 106.
0.1 to 3 parts by wsight and preferabl~ .5 to
1.5 parts by weight of said solid carbonaceous ~uel-liquid
hydrocarbon fuel slurry are introduced into the reaction
zone per part by weight of solid carbonaceous fuel-water slurry.
About o.8 to 12 parts by weight and preferably 2 to
12 parts by weight o~ total solid carbonaceous fuel are
reacted in ~he gas generator per part by weight o~ liquid
hydrocarbon fuel.
~ he e~luent gas stream ~rom the reaction zone
is split into tWo streams ~`or coollng, cleaning, and ~or re-
moving entrained solid~. One gas st~eam is cooled in a
waste-heat boiler and the other is coolsd by quenching ln ~`
water in an ~uench vessel. If desired, acid ~ases i.e. ~2Sg
COS, C02, and mixtures thereof may be removed from the
effluent gas stream. ~y this means fuel gas may be produced
whlch may be bu~ned without contaminating the environment.
Also, the heating ~alue may be increased. Alternately~ the
product gas may be used as a synthesis gas ~eed whlch dQes
not Rf~ect sulfur-seQ~it~ve catalysts.
The effluent gas stream leaving the synthes~s gas-
generator has the ~ollo~ing co~position in mole %: H28.o to
60.0, CO 8.o to 70.0~ C02 loO to 50.0, ~ 0 2.0 to 50. 03 CH4 0
to 30.0, H2S O.O to 1.0, COS 0.0 to 0.7, N2 ~ to 85.o, and
A 0.0 to 2Ø Entrained in the e~luent gas stream is about
.5 to 10 weight perc0nt of partlculate carbon (basi~ weight
of carbon in the ~eed to the gas generator). As previou~ly
,:
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mentioned the efrluent gas stream is then split into two
gas stream~ ~hich are ~epar~tely ~oled.
The first split stream of e~luent gas c~mprisin~
about 5 to 95 volume percent and preferably ab~ut 75 to 95
of the total volume of effluent gas from the gas generator
is cooled to a temperature ~n the range of about 200 tQ
1800F. ~nd preferably from 400 to 600F. by indirect heat
exchange with water in a wa~te heat boiler. Steam is
simultaneously produced at a temperature in the range of
abou~ ~00 to 650F. The particulate carbon is scrubbed
from the ~irst split stream of effluent gas by conventional
methods using a li~uid hydrocarbon fuel scnubbing flu~d.
For example, as shown in coa~signed U.S. Patent ~o,
3,63g,26~ the process ga~ stream ma~ be passed through a
venturi or ~et scrubber, such as described in Perry's
Chemical Engineers~ Handbook~ Fourth Edition, McGraw Hill,
Co., 1963~ pages 18-55 to 56 and scrubbed with a scrubbing
fluid selected from a li~uid hydrocarbon ~uel ~9 pre~lou~y
described or a dispersion o~ particulate carbon and liquid
hydrocarbon ~uel. Then in a conventional oil knockout pot, ~ :
the proce~s gas ~tream i~ s~parated from a di~p~r~o~
o~ particulate carbon-liquld hydrocarbon ~uel containing ~rom
about 1 to 20 wt. % ~nlids ~hich i8 ~em~ved fr~m th~ bo~ttom o~ :
~he knockout pot and mlxed with ground solld carbonlferous ~:
fuel in a conventional grlnding system. The aforesaid
~irst slRrry feedstream is produced thereby and is intro-
duced into the synthesis gas generator as previGusly
described.
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93~ :
Any particulate carbon and other entrained solids
such as a small a~ount of ash i~ a;ny remaining in the process
gas stream may be removed ln a second sc~bbing stage. In
such event, the process gas stream may be passed through an
orif`ice scrubber similar to that pre~iousl~ described in
the first scrubbing stage and scrubbed with water. Then ~n
a water knockout pot, a ¢lean pro~ ct gas cont~ ning less
than f~ve mg of particulate carbon per 100 SCF of gas iæ
separated from a water disper~ion con~aining from about
.001 to .2 wt. ~ of entrained solids. This dispersion may be
subsequently concentrated in a manner to be further described
and used as a portion of` the ~eed to the gas generator.
Ga~eous impuritie~ may be removed from khe process gas stream
by con~entional p~cedures.
The previously mentloned ~econd split stream of
effluent gas from the gas generator is cooled by direct
quenching in water ln a quench tank ~uch as shown in co-
assigned U.S. Patent Mo. 2,896,927. As the process gas stream
bubbles through water maintained at a temperature in the
range o~ about 50 to l~50F. 3ubstantially all o~ the particulate
carbon and other entraine~ solid~ ~uch as a~h are scrubbed
~rom the proce~s gas stream and wat~r i5 vaporlzed. Product
gas ~aturated with water leaves near the top of the quench
tank. Optionally, ~his gas stream may be sub~ected to ~ater- -
gas shift reactio~ to increase the ~2/CO ratio. H20 and any
gaseous impuritie~ may be then remo~ed by conventional methods.
A water disper~lon of partlculate carbon and ash
containing abo~t .1 to 2.0 wt. % of solids from the bottom o~
the water quench tank, i~ mixed with the di~per3ion o~ water
~nd e~trained solid~ e.g, particu}ate carbon, from l;he .;
pre~iously de~cribed water knockout pot~ ~y conventional
:.
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llquid-solids separation procedureæ e.g. settling,
filtration, and centri~uge clarified water is separated
from said dispersion. For example, ~he dispersio~ may be -~
passed into a settling ta~k fr~m which the following
three streams are removed: a stream o~ co~rse ash which
is removed ~r~m the bottom of the tank~ a water dlspersion
stream of fine ash and particulate c~rbon containing about ~;
l.O to 20 weight percent o~ sollds wh~ch i~ removed and
passed into a con~entional ~roth flotation process, and
a clari~ied water stream which i recycled to the water
quench tank. A two-stage flotation system may be used to
re~ol~e said water dlspersion into separate ~treams of
water, a stream of ash, and a concentrated part~culate
carbon water sl~rry stream.
This concentrated particulate carbon
water slurry stream contains about 10.0 to 40.0 weight
percent of solids and is ~assed into a hold up tank
from whence it provides li~uid for slurry make-up or for
wet grinding o~ the solid fuel. Ground make up solid
~0 carbonaceous fuel may be introduced in said mix and hold
up tank. For example about 20 to 70 weight percent o~
solid fuel introduced into mix and hold up tank comprises
said solld carbonaceous fuel m~ke-up. A pumpable
mixture of solid ~uelæ and water containing 30 to 65 wt. % ;~
solid~ from said mix and hold up tank i8 preferably
in~roduced into the gas generator as said first reactant
~lurry ætream.
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lq)~g~
Optionally, the product gas stream from
the water knockout pot or the product gas stream fr~m
the water quench tank may be submitted to additional
cleaning and conventional puri~ication steps to remove
any remainlng solids or at least one ~aterial from the
group consi~ting of H20~ C02, ~, H2S, COS, A, and
2^
DESC~IPTIO~ 0~ THE DRAWING
AND EXA~PIES ~:
A more complete understanding o~ the
lnvention may be had by reference to the accompa~ing
sch~matlc drawing which shows in Figure 1 the pre-
viously described proce~s in detail. Quantities have
been assigned to the various streams so that the
~ollowing description in Example 1 may be also se~ve
as an example o~ the sub~ect invention.
EXAMPIE I
:`'
On an hourly basis about 2750 lbs. of
a ground solid carbon~ceous ~uel-particulate carbon-
water ~lurry ~eed in line 1 in li~uid phase at a
temperature of abou~ 60F. are passed through the outer
annul~r passage 2 and discharged into the reaction zone
of synthesis ~as generator 20 by way of converging
ou~er annular orifice 3 of double annulus burner 4 at a
veloclty o~ 80 feet per second.
.. .
-14- ~
..
- , .. ... . . .. .
~OS~3;~0
.
An enlarged vert~cal ~ross sectlonal
~iew of burner 4 is shown in Fig. 2. Double annulus
burner 4 is more fully described in coassigned U~S. ...
Pat~ t 3,705,108. Other features of the burner
include concentric intermediate annular passage 5
which leads to concentric converging intermediate :
annular discharge nozzle 6 and central conduit 7 ;~
which leads to central nozzle or orifice 8. At
the t~p of the burner is hollow annular coollng
~hamber 9 through which cooling water is lntroduced
by w~y o~ line 10. Tubing 11 through which cooling
wate~ i~ pa~sed, encircles the outside barrel 12
of burner 4. By means of mownting plat~ 13, burner 4
is attached to the upper flange of burner houslng 1~. :
Housing 14 is attach~d to flanged inlet 15 of
vertical free-~low noncatalytic partial oxidation
synthesis gas generator 20 having a 33 cubic feet :
refractory lined reaction chamber 21.
The a~oresaid solid carbonaceous ~uel-
particulate carbon-water slurry is pumped into line 1
by means o~ pump 22. This water slur~y comes from line
23 ~nd mix and hold up tank 2~. In Run ~o. 1~ its . . :
composition in weight percent comprises Utah bituminou~ ;
coal ,ground to a particle s~ze so that 10 ~ of the
mater~al pa~ses through an ASTM Ell-70 Sieve
Designation Standard 425~m a~d at least 80% passes
through an AS~M E 11-70 Sieve Designation Standard
75~ m 49.0~ p~rti~ula~e carbon (produced sub-
Gequently in the proce~) 1.0, and wa~er 50Ø
.. .
: ... ...
~ S93ZO ~'
The material~ which are introduced into tank 24
and mix~d together therein comprise ground make-up
Utah bituminous coal from line 25, and a concentrated
dispersion of particulate carbo~ and water containing
10 weight percent of solids from line 26. m e U~ah ~
bituminous coal has the ~ollowing ultlmate analysis ~ -
in wt. %: C 78.9, H 7.5, N 1.1, S 1.1, 0 7 2,
and Ash 4.2. Gros~ Heatlng Value of the co~l is
15,737 BTU/lb.
Simultaneously, about 4125 lbs. o~ a
ground solid carbonaceous ~uel-particulate carbon-
llguid hydrocarbon fuel slurry feed ln line 30, ln
liguid pha~e, at a temperature o~ about 200F.
are pa~sed through central condult 7 of bux~er 4 ~ ; -
and are discharged into the gas generator reactio~
zone 21 khrough central nozzle 8 ak a velocity of -
about 50 ft. per sec. ~he ~olid ~uel-liquid hydro- ;
carbon fuel slurry in line 30 ~or Run No. 1 is
prepared by grinding together i~ conventional
grinding ~ystem 31, 2063 lbs. of Utah bituminous
coal make-up (as previously described) ~rom line
32, and 2062 lbs. of a dispersion ~rom line 33
containing 0.4 ~t. % solids and comprising particulate
carbon and 13.7~API California Reduced Crude make-up.
The reduced crude has the following ultimate a~alysis
in wt. %: C 85.8, H 11.26,S ~98,o o .11, and N ~.~0,
Ash 0O05~ and a ~eat of Combu~tion of 18~410 BTU per 1~.
~'~
-16~
.,: ,
... .
: ,.~ . ,. ~. . ... . .
~S~3
Simultaneously, about 5~17 lbs. of
substantially pure o~;yge~ (99.7 mole % 2) feed in line
40 a,t a temperature of about 100F. are pa~sd through
~ntermediate annular pa~sage 5 and discharj3ed into the ~ ;
j~as g~nerator reaction zone 21 through conver;ging inter-
mediats annular nozzle 6 at a ~eloclty o~ about 350 ft.
per see. By this arrangement o~ ~eedstreams, a stream
of substantialSy pure oxygen gas i~ di~ch~rged fr~m the
. burner and is interposed between the oil-slurry stream
and the water-slurry ~tream. Upon disch~rge ~rom burner
4, the three reactant stream~ contact each other ~n the
reaction zone with such ~orce as to pulverlze the
particle~ o~ bituminous coal. The ~lurry streams are
atomized and thoroughly mixed with the oxygen stream.
Reaction takes place in reaction zone 21 of
~ynthesi~ gas generator 20 at an autogenoua ~emperatura
o~ about 2600F., and a pres~ure of about 28 atmo~pheres~
The realdence time in the reaction zone i~ 2 seconds. `.
241,400 standard cubic feet per hour (SCFH) of
2Q e~fluent stream o~ ~ynthesis gas leave ga~ generator 20
by ~ay of fl~n~ed exit ~1 and lin~ 42 with the following
compo~i~ion in mole % ~or Run No. 1: H2 33 5~ C0 53.1,
o2 3~4~ H20 9.3, CH4 .1~ COS .02, ~S .2, N .3,
A. .1, and 4.0 ~t. ~ of particulate carbon (~asi~ weight
o~ total carbon ~n the ~eedstock to the gaa generator).
;:
~17-
~6~5~;3f~
~ .,.~ ; i . .
. The e~lue~t stream o~ synthesis gas $n
line 42 is split into two streams. The ~irst
spllt stream Or effluent gas i~ pas~ed through line 43 -
and into waæte heat boiler 44 where it is cooled to a
~emperature of 630F. by indireet heat exchange ~ith
boiler ~eed ~ater, enterlng through llne 45 at a
tempera~ure o~ 200F. and leaving through line ~6 a~
steam at a temperature of 590~F. ~he ~econd split
stream o~ e~fluent gas iæ passed through 1 ne 47 and . ~.
ls cooled by dlrect quenching in water in a quench ..
tank 48. Quench tank 48 i9 further de~cribed in co-
assigned U.S. 2~896~927. The product gas leavlng
guench t~nk 48 by way o~ line 49 is saturated with
waber. Optionally, the product gas in line 49 m~ be
introduced into a conventional gas cleaning and
purification zone (not shown in the dra~ing) where
any remaining ~olids are removed and one or more . .
gaseous impurities from the group C02, H2S, COS, A~ CH4,
~ 0, and ~z may be removed.
Partlculate carbon in the aforesaid flrst
spll~ ~tream of e~luent ga~ leaving waste heat boiler 44
b~.llne 55, ma~ be removed by passin~ said ef~luent ga~ ~,
~tream through a conventional ori~ice scrubber 56. The
.
~crubbing fluid whlch enters scrubber 56 by way o~ line
57 is ~ mixture of Cal~fornia Re~uced Crude make-up ~as
pre~lously descrlbed)~hich enters~the system through line
58 and a di~persion from llne 59 comprising partlculate
carbon and California Reduced Crude. Thi~ dispersion con-
8i~t~ 0~ about 0.~ wt.% 801ids ~nd i8 pumped by mean3 of pump 60
. '
-18- ~.-
3L~SS~3~?
,~ ,
from the bottom o~ oil knockout pot 61 through lines 65,
66, and 59. A portion o~ this dispersion i5 introduced
into grinding system 31 by way of line 33 as previously ~-
described. The process gas stream ~d scrubbing oil
mixture leaving ori~ice scrubber 56 by way o~ line 62 ' ,
is pa~sed into oil knockout pot 61 where the normally
liquid dispersion separates and is drawn o~f near the
bottom as previously described. me clean process gas
stream leaves through line 68 near the top o~ oil
knockout pot 61. Optionally, to remove any remaining
particulate carbon, the gas stream is passed through
conYentional orifice scrubber ~9 and scrubbed with water
~rom line 70. ~his water may include ~resh make-up
watex. The process eas stream is then introduced into
knookout pot 75 where clean product gas i8 removed through ~ ;'
llne 76 near the top o~ knockout pot 7~. The composition
of this product gas stream iB slmilar to th~t in line 49
with the exception that the water content is less than
10 mole percent and the wt. ~ o~ particulate carbon (basis
weight of total carbon in the ~eedstock to the gas generator)
i8 les~ than 6 parts p0r million. Optiona~,ly, H20 and on~ ~'
or more gaseous impurities from the gr~up C02, H2S, COS~ A~ ,
and N2may be removed from the produc~ gas stream in line 7Q
in a conve~tional gas puri~ication zone not shown in the' ,,
drawing. A ~ater di~persion containing 0.1 wt. % ~olids
su~sta~tiA~ly com~rising particulate carbon and ~pt~onally
some ash i8 removed through line 77 at the bottom of pot
75.
The disperslon of water and solid particle~ in
line 77 i~ mlxed in line 78 with the dispersion o~ water and
801~d particIes ~ontaining 1.0~ % solids e.g, partlculat0
-19-
.
~L~593'~0 ~ :
carbon and any ash leav~ng wa~er quench tank ~8 by way o~ line -
79. The mixture is passed into a conventional settler.unit 80.
Clarified water is removed by way of line 81 and by means of
pump 82 is recycled to wat r quench tank ~8 through line 83. .
A water slurry of p~rticulate carbon and any ~ine ash .. .
~s removed from settler unit 80 and is passed through line 84 ~-
into a conven~ional ~roth flotation unit 85. Any c~rse ash may .
.
~e remo~ed from settler 80 through 86. In flotation unit : :
85, any fine ash may be r~moved by way of line 87 and water
may be removed by way of line 88. S~me of this ~ater may be
treated and discharged from the system for disposal while other
portions of this water may be rec~cled to quench tank 48 or to ..
ori~ic0 scrubber 70 or to bo~h. A co~centrated disper~ion
o~ partlculate carbon and water is removed by way of line 26
and i5 passed into ~lx and hold up tank 24, as previousl~
described. 245 lbs. of ash or other solids may be removed
from the syætem by way of lines 86 and 87.
To show the advantages of the subject process
over systems e~ployi~g a single slurry feed ~tream, rune
2 and 3 which do not ~epresent the gQbJe~t invention are ..
shown below in Table III in comparison with the proceæs of
the sub~ect in~ention (Run No. 1). ~he operatlng
conditions, ~nd the amount of synthesis gas produced in all
th~ee runs are about the same. In Run No. 2 the ~eed to the
burner comprises: a coal-particulate carbon-emulsion of .: .
li~uid hydrocarbon fuel and water pumpable slurry~ and a
separate stream of free-oxygen containing gas. In Run No.
3 the feed to the burner comprises: a coal-particul~te
carbon-wat~r pumpable slurry; and a separate stream of free- - .
oxygen containing gas. ~ :
-20- .
~35~3;2~ :
~; , o , o o~ o I
~r~ I o , o ~ ODOO~O ~0 1 0~0 '
C , o , "~ .......... ~,,.l~
.
~ . .
: I I ~ O~) ~D 000 r~l (N N~O ~ ~
I I ~ oa:)L~OOC~J~0 C~ O
. ~ ~ {) 0~ ,,
'`~'` ~ ' .
: ~ .
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. ',.',
Lr~ O I O ~O~ ~OO ~ L~ O .:
c~ o:1 o ~ ~1 o o c~ ~no o c~ o oo~:) o
C~J .
~ I :C`J
~ ~ ~
;
,~ ~
,.~,
~q ~
.:
~ ~
,.,~
~I~ r~
r~ O ha)'Cl ~ I
~ g c~ g h;~ g o ~
U~ ~ _, ~ ,/~ ~ ,Q h O 1~ h O
t21 ~d h h ~ ~~ ~ bD ~ ~ h
O ~ O
,0
- O ~
~ 0 ~ P, ~ ~ ~ ~IXI h
0 ~2
c~ v ~ v ~ 3$
~ V ~ Ou~
aS
0 (D h ~10 ~
I I I O ~1~ ~ bD ~ ~1 ~
~ ~ ~ ~ ~ ~ ~ 0~
- - .
~5~3~ :
From Table III it is re~dily apparent tha-t
the perf`o~ce ch~racteristics for ~ ~;mlber 1 ~hich
represents the subject in~rention, are supe~rior to that
o~ the other Runs. Significant economic ~avings are
ef~ected a~d a more stable operation ls attainable by
the sub~ect invention. This is evident by the increa~ed -
production of H2~C0 per lb. of ~uel charged; the higher
ratio of total solid fuel/liquid hydrocarbon ~uel; the
lower oXygen consumption per MSCF H2~CO; and the reduced
water to ~uel ratio.
The proce~s of the invention has been
described generally and by example~ Wlth re~erence to
liquid-801id carbonl~erou~ ~u~l slurries ~nd synthesi~
gas of particular compositlons ~or purposes o~ cla~it~
and illu3tration only~ It will be apparent to those
skilled in the art from the foregoing that various
modi~ications o~ the process and ma~erials di~clo~ed
herein can be made without departure ~rom the ~pirit
o~ the ~nvention.
-22-
.
; , ~:
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