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Патент USA US3078672

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Feb. 26, 1963
A. G. RoccHlNl ETAL
Filed Feb. 24. 1959
`l? a
States Patent @ffice
Patented Feb. 26, 1963
bustion of a residual fuel oil containing vanadium com
pounds, vigorously attack various metals, their alloys,
and other materials at the elevated temperatures en
countered in the combustion gases, the rate of attack
becoming progressively more severe as the temperature
Albert G. Rocchini, Oaicmont, and Charles E. Trautman,
Cheswiclr, Pa., assignors to Gulf Research & Develop
ment Company, Pittsburgh, Pa., a corporation of Del
is increased. lThe vanadium-containing ash forms de
posits on the parts affected and corrosively reacts with
Filed Feb. 24, 1959, Ser. No. 795,036
7 Claims. (Cl. eil-39.02)
It is a hard, adherent material when cooled to
ordinary temperatures.
This invention relates to vanadium-containing petro
leum fuels. More particularly, it is concerned with ren
dering non-corrosive those residual fuels which contain
such an amount of vanadium as normally to yield a
corrosive-vanadinni-containing ash upon combustion.
It has been observed that when a residual type fuel
oil containing substantial amounts of vanadium is burned
lt has already been proposed to employ in corrosive
residual fuels small amounts of certain metal compounds
to mitigate the vanadium corrosion. Such compounds
are of varying effectiveness and it has not always been
possible to reduce vanadium induced corrosion to a mini
15 mum amount.
in furnaces, boilers and gas turbines, the ash resulting
from combustion of the fuel oil is highly corrosive
materials of construction at’elevated temperatures and
attacks such parts as boiler tubes, hangers, turbine blades
and the like. Theseieifects are particularly noticeable v ’
It has now been discovered that residual petroleum
fuels containing vanadium in an amount sufficient to yield
a corrosive vanadium-containing ash upon combustion
can be rendered substantially non-corrosive by incorpor
ating therein to form a uniform bled (l) a small amount
of a vanadium-free aluminum compound su?'icient to,
retardjthe corrosiveness of the ash, and (2) a small
ingas turbines. Large gas turbines show promise of be
amount of a vanadium-free alkali metal compound suf
coming an important type of industrial prime mover.
iicient' to furtherreduce the corrosiveness of said ash to
However, economic considerations based on the eñîciency 25 a minimum.' In they fuel compositions of the invention
of, the gas turbinedictate the use of. a fuel for this pur
the coaction `of the two additive compounds is such that
pose which is cheaper than a distillate diesel fuel; other
the corrosion 'is reducedto'negligible amounts.
wise, other forms of power suchA as'diesel engines .be
V‘In the accompanying drawing, thesingle FIGURE shows
comes competitive withy gas turbines.
a î w
. One of the main problems arising inthe use :of `resi
anfappa'ratus‘for» testing'thejcorrosivity of residual fuel
dual fuel `oils in gas turbines >is the corrosiveness` induced
fuel oils asnormally obtained in the reñnery'contain
so`little vanadium,-or none, as'to present Anofcorrosion
problems, such non-corrosive fuel oils are not always
factors appear to militate against the extensive use ofI
residual fuel oils for gas turbines.
_ l corro
Aside from
sion; the formation of deposits upon the burning'of a
residual fuel in a gas turbine mayïresult in unbalance‘
o'fßtheturbine blades, clogging- of openings and reduced
thermal eñìciencyof the turbine.>
~ Substantially identical problems are encountered when
known tothe’art. For example,`residual1fuel oils are `ob
tained as liquid residua` by the conventional distillation of
total'cru'des, 'by atmospheric and vacuum reduction of
total crudes, by thethermal crackingy of topped crude's,y
theresidual'oil loses‘its competitive advantage. These
fuel oils which contain a su?li'cjient' amount of vanadium to
form acorrosive ash upon combustion.' These are resid
ual type fuel voils obtained from petroleum by methods`
present or the amount of vanadium is small, noappref
ciabl'eI corrosion is encountered. While many'residual
such instance, -the- cost of transportation of-the non-‘cor
rosive oilto the point of usel is often prohibitive, and`
directed'is exemplilied by No._ 45,'No7 6 and Bunker “C”
Where vno » vanadium `is'
available at the pointrwhe're the oil is to be used.
'y The- type‘ef residual »fuel cils to which -th‘e invention is
by those residual fuels containing sufrlcientamounts` of
vanadium -to` cause corrosion.
by visbreaking»heavypetroleum residua, and other con
ventional treatments of 'heavy petroleum oils. ï lìesidua'k
` thus obtained are sometimes diluted with distillate fuel
oil stocks, yknown as “cutter” ~`stocks, and theinvention
also includes residual fuel oils so obtained, provided that
suchboils contain suiiicient 'vanadiumïn‘ormally to ‘exhibit’E
the corrosion >characteristics described V herein. _ ¿It sl'íoulilI
` be lux‘lderstood that distillatefuel oils themselves contain"
\ either no vanadium yor* such small amounts'- as topresent
no‘p'roblem of corrosion. >'I'he’total ash from commercial
using a solid residual petroleum fuel containing substan# 50 residual fuel'oils usually ranges from about 0_.02‘to _0.2‘
tial? amounts of vanadium. .These fuels are petroleumy
residues obtained by known methods of petroleum reñning such as deep vacuum reduction v-ofasphaltic crudes’
to obtain solid residues, visbreaking of :liquid distillation'
percent by' weight; Thevvanadium pentoxide (V205) con-`
Ä tent _of such ashes ranges from -Zero‘to trace »amounts up'
to about 5 percent by Weight for low Vanadium stocks,y ex;y
hibitingl no signiñcant vanadium corrosion problem, toas"
bottoms followed by distillation to obtain. solid residues, 55 much as 8S percent by weight for some ofthe high vana#
colcing ofyli'quid distillation bottoms and the like. fïThe».
solid residues thus obtained are known variously'as petro
leum pitches or cokes and find use as fuels. Since the
vanadium content of the Í‘original crude oil tends to con
dium stocks, Y' exhibiting ‘severe corrosion.
*The type of vanadium-containing' solid residual fuels' to.v
1 whichv the» invention‘is' directed is> exemplified by the cokel
obtained in’known manner by the rdelayed thermal "cokin'g
centratey in the residual fractions, and' since the process
ing of the residual fractions to solid residues results inI
or fluidi-Zed coking of topped or reduced crude oil'sand bye
further concentrationof the yanadium in the solid residues,
the vanadium` corrosion problem tends to-beintensilied
um reduction of asphaltic. crudes 'to obtainsolid residues'. `
v These materials have ash contents'` of the ordert of- 0.218
inusingthe solidresidues as fuel.k ,
The vanadium~containing ash present inthe 4hot lluef
the pitches obtained in `known manner byl the deep vacu@
percent by weight,l more or-'1ess,` andrcontain Ycorrosivei
amounts of vanadium when :prepared vfrom stocks-con#
taining substantial amounts of vanadium". A typical pitch”>
taining substantial amounts of vanadiur'ri- compounds~
exhibiting corrosive characteristics uponcombustion had.~
causes “catastrophic”. corrosion ofthe turbine blades 1": a softening ‘point’ lof1347° F; and arvanadiu'mcontent‘, ‘as
and Iother metal parts Ain a gas turbine. The corrosive
vanadium,~ of 578 parts permillion. "
nature-of the ash appears to be due to‘ its -vanadiu'm ‘oxide
' I`A`ny"alurninum "compound, organic or inorganic,which'`r
content.- -Certain'inorganic compounds of vanadium, such*v
is" free from vanadium lis used as 'the `aluminumvadditive'
as 'vanadiuml oxide (V205), which'vare formedo'n fcom'-v
of the inventions Similarly, anyforga’nic vor- inorganic
gas obtained from, theburning of a residual fuel-,con
the mixture can` then. be subjected to the refiningproceu
vanadium-free alkali metal. compound is employed. The
alkali metals include sodium, potassium, lithium, cesium
which will produce the solid, fuel. For example, in the
production of a pitch by the> deep vacuum reduction of
and rubidium; sodium and potassium compounds are re
an asphaltic crude oil, the additives or a concentrate
ferred. Such inorganic alkali metal and aluminum com-
thereof are slurried with the oil in proportion to the
pounds as` the. oxides, hydroxides‘,v acetates, carbonates,
vanadium content thereof, and the whole subjected to
deep vacuum reductionV to obtain a pitch containing the
silicates, oxalates, sulfates», nitrates, halides and the like
are successfully employed. In4 this` connection, the mix~
additives uniformly dispersed therein. As stillV another
alternative, particularly with a pitchl whichis withdrawn
ture., of` salts present in seawater, as disclosedV in: our`
copending; application Serial No. 654,812, filed April 24,.
1957, now` U_.-S.. Patent 2,966,029, comprises a suitabley 10 in molten form from the processing vessel, the additives`
can be mixed» withithe molten pitch and theï mixture al
alkali metalA compound. Aluminum oxide isa preferred.
lowed to solidify afterA which it is ground -to the desired
of 'aluminum and- the alkali metals include the oil-soluble
In the` case» of either liquid or solid residual fuels,
and oil-dispersible salts` of acidic, organic compounds such
as: (1_) the fatty acids, eg., valeric, caproic, 2-ethylhex 15 theV additives: can be separately fed into the „burner- ast
inorganic aluminum compound. The organic compounds
concentrated solutions or dispersions.
anoic, oleic, palmitic, stearic„ linoleic, tall oil, and the
like; (2) alkylaryl sulfonic acids,u e.g.,_ oilfsoluble petrole
um sulfonic acids and dodecylbenzene sulfonic acid;` (3)A
longchain alkylsulfuric` acids, eg., lauryl sulfuric acid;
(.Iiì‘petroleum rraphthenic,acids;(5)í rosinand-hydrogenatcd`
In such a case,
ity is preferred to meter the additives into the fuel line
just prior to thecombustion zone. In a'gas turbine plant
where the heat resisting metallic parts'are'exposed‘to hot
20 combustion gasessat temperatures of the order ofi1200°
rosin; (6);,alkyl phenols,A e.g«., iso-octyl phenol, t«butyl-
F. and‘above, the additivestcan be'added separately `fromy
phenolsandthe like;` (7) `alkylphenol t sulfides, e.g.,.bis(iso.-`
oçtyl phenoDmonosulíidc, bis(t-butylphenol)disulfide, and
the fuel: either prior to` or during combustion itself, or
even subsequent' to combustion; However they may
speciñcallycbe added„whether inadmixture with on sepa
the likt?, (8)1îhc acids-obtained by theoxidation of- petro
leum‘waxesA and, other petroleum< fractions;A andi` (9)- oil 25 rately form` the fuel, the' additives are introduced into
said plant upstream of- thetheat resisting metal-` parts -`to`
solubleÈ phenolfformaldehyde resins, e.g., the; Amberols„
be‘protected from corrosion.
suchj as;ltfbutylphenobformaldehyde resin, and the; like;
The. aluminum compounds' and-r the alkali“ metal com
Since the: salts or; soapsgofisuch acidicorganiecompounds
pounds‘are. both employed in1small„corrosion retarding
t the-` fatty, acids, naphthenic. acids- andY rosins are rela-`
tively inexpensiveandV areeasily prepared,` these are pre-` 30 amounts with‘respect,tol'thelfuel, and'in‘such amounts‘l
with respect to’each‘V othery asI to `minimize the corrosive-v
ferred‘materials for` the, organic additives.
ness of the ash. Fortexample,- when1 the aluminum com»
When employingl in l residual ,fuels the inorganic addi-`
tives of the invention, it is desirable to useviinely-diyided,V
poundÍ` is employed in; an t amount‘ofï abou-t4 atomiweights
materials. However, the; degrce‘of subdivisiontis notvcrit
of. aluminum per atom. weight' off vanadium;Ä ordinarily.`
dispersion or4 susp_en_sion,¿ of« the) additiyesfwhenv blended;
corrosion to negligible amounts. Althoughlarg‘en amounts :1
ical.l -One1 requirement ,for usinga iinely-dividedïmaterial.
35 an. amount. ofïalkali metal: compound yielding about 1
atom.~ weight of; alkali metal‘ is" suflìcient- toÁ reduce'ß the“ `
isbased, upon, the i desirability- of forming, a fairly ç stableÁ
with: a., residual ¿ fuell oil... Furthermore, _. the more.A ñnelyf»
of,I theY alkali» metalí compound> can' be; employed;y
divided- rnaterials;- are“- moreeificient in forming.v uniform.
sired; no additional ‘ advantage» is- usually ‘ obtained,A t
blends and 'rendering noncorrosiyeÍ the. relatively small
amounts îof vanadium in.»a residualrfuel, whether the fuel
.solid ,or-liquid», Theinorganic additives;~ are ltherefore;
employed -_in_t a` particle _size rangeof less than ï215() .micron_s,=_
preferably less than.,5_0 microns.- However, where'` the
TheÍ following f examples are: further illustrative= oflfthe#
a .residual
of ‘aluminum
' fuel " oil
and 0.02percentb`y
blend ' 0.08 t" percent
inorganic- additiyes, are .» water-soluble, for example, , in Vthe
of sodium carbonate. Theresidual fuel ‘oil`cmployed"has».
caseoftaluminumsulfate, sodium carbonate, and the like„ 45 tlîie` following inspection;
it_-. is not-Y necessary to employ finely-dividedi materials
Gravity, ’APT
desired„the„additiyes can bedissolyed ínwater.<
Viscosity, 4Furol ; asec. z
tognform, a more,or„ less, concentrated solution. andthe
watersolution emulsiiied,in_.the'fuelA
The.- organic. additives of .- the _invention i are~ oil-solubleA 50
122° F
orfoil-dispersible': and are therefore ,readily blendedwithtv
residual `:fuels- to.,form uniformblends. Since on a weight,
Pîlash; OC,»„°’E
Eire, OC, °Ff
basis. in' relation to the fuel, the'` amounts of the additives
Sulfur, B,\ percent __________________________ __ 1.8`i
Ash, . percent
0.04 e'
are,v small, , itlmay be. desirableV tovtpreparev concentrated,
solutions’.` or..dispersionsz of> thevorganic» additives
a: 55
naphtha,_kerosene or gas.` oil for. convenience.> in. com«»`
In the practice of -theL invention with' vanadium-con-`
Vanadium, p.p.m. of oil __________________ ___-- 203i
Sodium, p.p.m.f ofïoiL ____________________ ____
The resulting composition has an atom weight ‘ratio’
of4 aluminum to vanadium of 4:1 andv an atom‘weight"
taining residual-fuel-,oils, the'mixture of` additives is uni
ratiov of sodium to vanadium `of 1:1.
formly. blended ïwith the oil. This is >accomplished by;
suspending the ñnely-divided. dry` additives-in theoil,`
emulsifying or.` dispersing arconcentratedíwater solution
Tothe samexresidual‘fuel oiljof Example'l,~ add andi
offthe water-soluble inorganieaddi-tives in the oil, ordis
uniformly blend 0.52' percent byweight of l aluminum.,`
solving _Yors dispersing the Vorganic additives `in the` oil.
sulfate, Al2(SO¿)3.18H2O, and> 0.12‘ percent by‘ weight
If` desired, suitable surfaceactive agents, such as‘sorbitan 65 fo a solution of ‘sodium petroleum naphthenate in naphtha „
monooleateandmonolaurate andsthe ethylene oxide,con-.
containing 7 percent by ‘weight of sodium. The resulting
densationiproducts thereof,gglycerol monooleate, and the.
composition has an atom‘ weight ratio‘ of' aluminum to
like, _which- promote ìthe ,stability of :the suspensions or
vanadium> of `4:1 and an atom weight ratio of sodium toA
emulsionscan be employed.
of 1:1.
In .the 1 practice „'ofrthe invention .with .the ,solid residualY 70 `
fuels, incorporation of .thexadditives `of the inventionV is.`
accomplished in severalways.' The additives can be- sus
pended, , emulsiiiedtor. l dissolved in .the ‘- liquid vanadium-`
containing residual stocksiorcrudeoil stocksifrom which:
Meltl-asolid petroleum pitch obtainedjfromthedeep
vacuum reduction of auf asphalticlcrude.- This i pitch“l
basa Lsoftening-_point off347° l?. and 1a vanadium content“l
the solid residual fuels of the invention are derived, and 75 of 578 parts per million. While the pitch is in molten
form, add and uniformly blend therein 0.23 percent by
weight lof aluminum oxide and v0.08 percent by weight
of sodium sulfate. Upon I„cooling and ,solidificatiom
products ofa residual fuel oil, the specimen being main
tained at a selected test temperature of, for example,
1350°, 1450° or 1550“ F. by the heat of the combustion
products. The test is usually run for a period of 100
grind the mixture to about 150 mesh. The resulting fuel
has an atom weightv 'ratio fof aluminum 4to vanadium of
4:;1î and an atom ‘we1ght rat1o of sodium to vanadium of
hours with the rateof fuel feed being 1/2 pound per hour
and _the rate of atomizln-g an' feed` being 2vpounds per
_ ,
The .combustion air entering through air inlet 31
In order vto test the effectiveness of the additives of this
is fedr at 25 pounds per bouh . Atm@ end of the’ test 'mml
invention under con-ditions v. of burning residual fuels` in
the specimen isreweighed to determinethe Weight of de.`
a gas turbine, the apparatus shownin the drawing is em- 10 posits `and is then descaled with a conventional alkalinez
ployed. As shown therein, the residual oil under test is ` descaling salt ‘in` molten lcondition at 475° C.. After
introduced through line 10 into a heating coil 11 disposed
ldesc'aling, the specimen is-dippedin-6 ÁN hydrochloric acid
in a tank of water 12 maintained at such temperature that
containing a conventionalV pickling inhibitor, and isy then.
the incoming fuel is preheated to a temperature of ap~
washed, driedand weighed. The lossl in weight of the
proximately 212° F.
From the heating coil 11 the pre- 15y specimen after ydescaling is the corrosion loss.
heated oil is passed into an atomizing head designated general‘ly as 13. The preheated oil passes through a passageway 14 into a nozzle 1S which consists of a #26 hypodermic needle of approximately 0.008 inch LD. and 0.018
c _ _
Tests are conducted in the apparatus just describedv
using a l257-20 stainless steel as `the test specimen. . The
tests are run forA 4100 hours at a temperature of 1450"v F.
under the conditions described above. Tests are made`
inch `O._D. The tip of the nozzle is ground square and 20. with `the fueloil `composition ofk Example Lwith similar
allowed to project slightly through> an oritice 16 of ap- " fuel oil compositions but containing only oneof the addi-1
proximately 0.020 inch diameter. yThe oritice is supplied
tives in varying proportions, and withthe uncompounded
with l55`i.g. air for atomization of the fuel into the
residualfuel'A oil of Example I.y The same base ~fuel is
com-bustion chamber 21. The air is introduced ythrough
used inall thetests. The following table ¿shows the cor~v
line 17,` preheat coil 10 iny tank 12, and air passageways 2.5.Í rosion and deposits obtained.
Table 1
Wt. Loss oi
Mg/Sq. In.
Uncompounded Fuel of Example I......................... __
Fuel+Sodium Carbonate .................. ._
Atom Wt.
Metal: V
' l
l, 151
Hard Scale.
Hard Granular.
Hard Scale.
Do ____ __
Hard Powdery.
Fuel-{"Aluminum Oxide
1:1 ......... _.
FuîEH-_ìluminum Oxide-i-Sodium Carbonate
___________________________________ _.
100 powdery
19 and 20 in the atomizing head 13. The combustion
It will be seen from the preceding table that, although
chamber 21 is made up of two concentric cylinders 22
the alkali metal and aluminum additives individually tend
and 23, respectively, welded to two end plates 24 and 2'5.
to reduce corrosion and deposits, substantial corrosion
Cylinder 22 has a diameter of 2 inches and cylinder 23
and deposits are nevertheless obtained. This is apparent
has a diameter of 3 inches; the length of the cylinders
even when relatively larger amounts of the individual
between the end plates is 81/2 inches. End plate 2d has
additives are employed, for example, in atom weight
a central opening 26 into which the atomizing head is 50 ratios of additive metal to vanadium on the order of 4:1
inserted. End plate 25 has a one (l) inch opening 27
and 5:1. However, when the additives are employed in
covered by a baille plate 28 mounted in front of it to
combination, corrosion and deposits are unexpectedly
prevent direct blast of flame on the test specimen 29.
minimized. Thus, it will be noted that the aluminum
Opening 27 in end plate 25 discharges into a smaller
additive and the alkali metal additive when individually
cylinder 30 having a diameter of 11/2 inches and a length 55 employed in the same total additive content as the com
of 6 inches. The specimen 29 is mounted near the down
bination of >additives do not minimize corrosion and de
stream end of the cylinder approximately 1% inches from
posits. Similar results to those shown for the specific
the outlet thereof. Combustion air is introduced by
additives employed in the examples and in the preceding
means of air inlet 3l into the annulus between cylinders
22 and 23, thereby preheating the combustion air, and
then through three pairs of 3m; inch tangential air inlets
table are obtained when using the other aluminum and
60 alkali metal compounds disclosed.
A typical analysis of the 25-20 stainless steel employed
32 in the inner cylinder 22. The first pair of air inlets
in the testing described is shown in the following table
is spaced 1A inch from end plate 24; the second pair 3%:
in percent by weight:
inch from the first; and the third 3 inches from the sec
Table Il
ond. The additional heating required to bring the com 65
bustion products to test temperature is supplied by an
electric heating coil 33 surrounding the outer cylinder 23.
_____ __
The entire combustion assembly is surrounded by suitable
insulation 34.
The test specimen 29 is a metal disc one
inch in diameter by 0.125 inch thick, with a hole in the 70
center by means of which the specimen is attached to a
tube 35 containing thermocouples. The specimen and
tube assembly are mounted on a suitable stand 36.
In conducting a test in the above-described apparatus,
a weighed metal specimen is exposed to the combustion 75
_ _ _ __
Mn _______________________________________ __
P _____________ __
Fe _____________________________________ __ Balance
Resort may be had to such modifications and variations
as fali within the spirit of the' invention and the seopeof
the appended claims.
We claim:
l'. A fuel composition comprising a uniform blend ofi
a' maior amount of a residual petroleum fuel' yielding a
corrosive vanadium-containing ash upon combustion, anY
arriountof a vanadium-free aluminum compound yielding
about~ 4' atom weights of aluminum per atom weight'of
vanadium in said fuel, and an amount of a vanadium-free
alkali metal compound yielding aboutv 1 atom weight of
alkali metal per atom weight of vanadium in s'aid fue1._ _
2. The fuel composition of claim 1, wherein tlieî fuel
isa s‘olid‘residual petroleum fuel.
to' be corroded by the' corrosive vanadium-containing ash`
resulting from combustion of said oil, the method of re
ducin'g'r said corrosion which comprises introducing intoA
s'a'id plant upstream of said parts a small amount offal
vanadium-free mixture of an aluminum compoun‘dand an
alkali metal compound, the amount of said aluminum
compound being sufficient to yield about 4 atom weights
ofV aluminum per atom weight of vanadium in said fuel
oil and the amount of said alkali metal compound being
sufûcient to yield about 1 atom weight` of alkalimetal
p_er atom weight of vanadium insaid fuel oil.
References Cited in the tile of this patent
3. The fuel composition of claim 1, wherein the fuel is
a residual fuel oil and the alkali metal compound is“ aV 15
sodium compound.
4. The fuel composition’of claim 3, wherein the alumi
num compound> is aluminum oXideand the sodium com
pound is 'sodium carbonate.
51 The’fuel‘composition of` claim 3, wherein the alumi 26
n'um compound‘is'aluminum sulfate and the-'sodium com‘
poundïi‘ssodiu‘m naphthenate.
6l The fuel composition ofA claim 3, wherein'th‘e'alumi#
num" compound `is aluminum oxide andthe sodium com
pound is sodium sulfate.
7. In a gas turbine plant in which a fuel oil containing
vanadium is burned and which includes heat resisting
metallic parts exposed to hot combustion gases and liable
Rocchini et al _________ __ Aug; 16, 1960
Rocchini et al. _~.»_____-___. Jan.` 17, 1961
Australia _____________ _- Nov; 4, 1955
Belgium ______________ __ Feb.`15`, 1951
Great< Britain __________ __ Feb. 1, 1956
Great' Britain _________ __ Feb. 15, 1956
Great Britain1 .;_ ..... _..-_'.. Mar. 21, 19516‘
Greatv Britain.A_____ __'__^.. Nov.' 14,1956
Great Britain _________ __ Aug. 21, 1957
France _______________ __ Mar. 5, 1956
Switzerland __________ _.. Mar. 15, 1958
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