CA2109096A1 - Process for reducing nitrogen oxides emissions and improving the combustion efficiency of a turbine - Google Patents
Process for reducing nitrogen oxides emissions and improving the combustion efficiency of a turbineInfo
- Publication number
- CA2109096A1 CA2109096A1 CA 2109096 CA2109096A CA2109096A1 CA 2109096 A1 CA2109096 A1 CA 2109096A1 CA 2109096 CA2109096 CA 2109096 CA 2109096 A CA2109096 A CA 2109096A CA 2109096 A1 CA2109096 A1 CA 2109096A1
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- Canada
- Prior art keywords
- emulsion
- water
- emulsifier
- fuel
- dea
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
- C10L1/00—Liquid carbonaceous fuels
- C10L1/32—Liquid carbonaceous fuels consisting of coal-oil suspensions or aqueous emulsions or oil emulsions
- C10L1/328—Oil emulsions containing water or any other hydrophilic phase
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- Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Liquid Carbonaceous Fuels (AREA)
- Catalysts (AREA)
Abstract
2109096 9219701 PCTABS00017 A process for formation of an emulsion in emulsifiers (52 and 54) with water from water inlet (40) and fuel from fuel supply (120) and optionally an emulsifier from emulsifier supply (30) and injection of said emulsion into a combustion zone of a turbine by engine pump (136) to reduce nitrogen oxides and plume opacity and improve the combustion efficiency of a turbine.
Description
W~92~1~7~1 rCT/US9~/03328 9 ~ ! :
DESCRIPTION
P~iOCES8 FOR ~ED~CING ~ITROGEN OXIDEB ~ 8IONB ~ND
I~PRO~I~G ~E COMBUSTION EFFICIE~CY OF A T~RBI~E ~`-Related Application This application is a continuation-in-part of copend ing ~nd commonly assigned U.S. Patent ~pplication entitled "Improved Combustion Efficiency Water-ln-Fuel .-Oil Emulsion11, having Serial No. 07/603,266, filed in the name of Sprague on October 24, 1990, which in turn is a continuation of U.S. Patc-nt Application Serial No.
07/348,296, filed May 5, 1989, : now abandoned, the disclosures o~ which are incorporated herein by reference.
~ The present ln~enti~n~relates t~o a~process which:~will :
~improve the combustion ~-ef~lciency ~ o`~ a gas;~turbine:in order to reduce the ~emissiLons~o~f ~troge~ oxides (NOx~
~and visi~le~emissions~(~p:artic~lates,~which lead~to plume : : ~:
opacity~ ~:o~the~:atmosphe~e~
~ as or combustio~tur~ines have bèén~utilized~:by~many utillties as peaking~ units~;to~rapidly~;bring àdditional electrical generation~on:line~a:s~:requlred~and~,;henc~e,~are~
prefer~ed~ for many appli~ations~ Unfortunately~ the:~
:
:
'W~ 71)1 rCT/VS92/03328
DESCRIPTION
P~iOCES8 FOR ~ED~CING ~ITROGEN OXIDEB ~ 8IONB ~ND
I~PRO~I~G ~E COMBUSTION EFFICIE~CY OF A T~RBI~E ~`-Related Application This application is a continuation-in-part of copend ing ~nd commonly assigned U.S. Patent ~pplication entitled "Improved Combustion Efficiency Water-ln-Fuel .-Oil Emulsion11, having Serial No. 07/603,266, filed in the name of Sprague on October 24, 1990, which in turn is a continuation of U.S. Patc-nt Application Serial No.
07/348,296, filed May 5, 1989, : now abandoned, the disclosures o~ which are incorporated herein by reference.
~ The present ln~enti~n~relates t~o a~process which:~will :
~improve the combustion ~-ef~lciency ~ o`~ a gas;~turbine:in order to reduce the ~emissiLons~o~f ~troge~ oxides (NOx~
~and visi~le~emissions~(~p:artic~lates,~which lead~to plume : : ~:
opacity~ ~:o~the~:atmosphe~e~
~ as or combustio~tur~ines have bèén~utilized~:by~many utillties as peaking~ units~;to~rapidly~;bring àdditional electrical generation~on:line~a:s~:requlred~and~,;henc~e,~are~
prefer~ed~ for many appli~ations~ Unfortunately~ the:~
:
:
'W~ 71)1 rCT/VS92/03328
2 1~ 9 n9 b -2-temperatures at which gas turbines opexate tend to cause the production of thermal NOX, the temperatures being so high that free radicals of oxygen and nitrogen are formed and chemically combine as nitrogen oxides.
Nitrogen oxides are troublesome pollutants and comprise a major irritant in smog. It is further believed that nitrogen oxides can cause or enhance the process known as photochemical smog formation through a series of reactions in the presence of sunlight and hydrocarbons.
Moreover, nitrogen oxides are a significant contributor to acid rain and have been implicated in the undesirable warminy of the atmosphere through what is known as the "greenhouse effect" and in the depletion of the ozone layer. In addition, gas turbines often emit a visible plume, which is highly undesirable since it causes concern among the population in areas surrounding the facility.
Although the use of emulsified oils (primarily produced from relatively simple mechanical technigue~
for combustion improvemen~s has been suggested in the past, they have not:been~applied to gas turbines, and the oils emulsified are usually~ heavy oils (i.e., #5: oilj.
Because gas turbines are peaking units, the fuel is required to remain emulsified for at least 30 days in a holding tank, and at least 2 hours during in-line mixing . This has been dif f icul~ to accomplish, especially when using mechanical emulsion methodology.
In addition, gas turbines are very sensltive to corrosion, which often leads the practitioner to avoid introducing emulsified water into the combustion zone~
~'.
W~ 7~l PCT~US~2/03328 S
It has been known for some time that the injection of wa~er directly into the combustion zone (also referred to as the "combustion can") of a gas turbine at water to fuel ratios of greater than l:l can control the emission of NOX and reduce opacity to a limited extent. The direct injection of water into the combustion can, though, requires extensive mechanical modificatiQn of the gas turbine (with high capital cost) and in~olves thP ::
injection of large volumes of demineralized w~tter which results in ex~ensive additional maintenance and out ye time because of the the~mal shock to the combustion can.
What is desired, therefore, is a process which permits the reductic:~n of effluent nitrogen oxides and plume opacity from a gas turbine wi~hout the thermal ~.
shock, large capital costs, and other drawbacks of ;
injecting water directly .into the combustion can.
Brlef De ~
The present invention will be better understo~d and its ad~antages more apparent in view of the *ollowing .-de~ailed description, especialIy when read with reference to the appended drawings, wherein:
' FIGURE 1 is a schematic~ illu~stration of a gas turbine fu~l supply system :having an emulsification æystem -.
according to the present::invention installed therein;
~ IGU~E 2 is a schematic illustration of an emulsification system according to the present invention as installed in a gas turbine fuel supply system, and ~ -.
FIGURE 3 is a graphic representation of the results of Examples IIa and IIb.
., .
W~ tOI PCr/US92/03328 2 1 ~ 6 Disclosure of Invention The pr~sent in~ention relat~s to a method for reducing nitrogen oxides emissions and improving the combustion efficiency of a gas turbine (which term will be considered to be interchange~ble with ~omb~stion turbine). In particular, this invention relates to a process involving the formation of a stable water-and~
fuel oil emulsion, where the oil is a light fuel oil such as diesel fuel, distillate fuel or ~2 oil. The subject emulsion can be either a water-in-fuel oil or a fuel oil-in-water emulsion (although water-in-fuel oil emulsions ~re preferred for most applications),~and the introduction of the emulsion into at least one of the combustion cans of a gas turbine through its fuel system.
Typically, the oil phase in the inventive emulsions comprise what is conventiona:lly known as diesel fuel, distillate fuel, or #2 oil, as defined by the Amert an Society of Testing and Measurement (ASTM~ Standard Specification for Fuel Oils (~esignation: D 396-86).
Especi~lly preferred are distillate fuels. Included among these are kerosene and ~et ~uels, both commercial and military, commonly referred to as ~P4 and JP5, respectively.
Although demineralized water is n~t re~uired for the suc~essful control of nitrogen oxides and opacity, the use of , demineralized wat~r in the emulsion foxmed accordi~g t~ the process~of this invention is preferred in order to avoid the deposit of minerals from the wa~er on the blades and other iL~ernal surfaces of the gas turbine. In this way, turbine life is extended and maintenance and outage tlme signifi~antly reduced.
~ /lg7~l PC~`/U~92/03328 2~ 09VYij -The emulsions used in the fuel system of the gas turbine advantageously comprise water-in-fuel oil emulsions having up to about 50% w2ter by w ight. The emulsions of this type which have the most practical significance in combustion applications are those having at least abo~t 5% water and are preferably about 10% to about 35% water-in-fuel oil by weight. In addition, this invention also relates to the formation of fuel oil-in-water emulsions having about 50% to about 8b%
water, which have practical applicability in certain situations.
Advantageously, the emulsions are prepared such that the discontinuous phase (i.e., the water in a water-in-fuel-oil emulsion and the oil in an a fuel oil-in-water emulsion) has a particle size wherein at lea~t about 70%
of the droplets are below about 5 microns Sauter mean diameter. More preferably, at least about ~5~, and most pre~erably at least about 90~, are below about 5 microns Sauter mean diameter.
Emulsion stability is largely related ~o droplet si~e. The primary driving force for emulsion separation is the large energy associated with placing oil molecul s in close proximity to water molecules in the form of small droplets. Emulsion breakdown is controlled by how quickly droplets coalesce. Emulsion stabil~ity can be e~han~ed by the u~e of surfa~tants and the like, which ~Ict as ~mulsifiers or emulsidn stabilizers. These generally work by forming repulsiYe layers hetween droplets prohibiting coalescence~ The gravitational driving f orce for phase separatlon is much more pro~inent for large droplets,~ so lemulsions containing large droplets separate mosk rapidly.
W~ 7~)1 P~T/US92/03328 2 l 09~ 6-Smaller droplets also settle, but can be less prone to coalescence, which is the cause of creaming. If droplets are sufficiently small, the force of gravity acting on the droplet is small compar~d to thermal fluctuations or sub~le mechanical agitation forces. In this case ~he emulsion can beoome stable almost indefinitely, although given a long enough period of time or a combination of thermal fluctuations these emulsions ~ill eventually separate~ ' Because of the operating characteristics of gas turbines, ik is requixed that the water/fuel oil emulsion exhibit a high degree of st:ability. In most cases, gas turbines are "peaking" unit:s, as noted,. which do not operate regularly. Accordingly, an emulsified fuel mcy sit stagnant for extended pe.riods or with only mild recirculation in the fuel line. In order to avoid separation of the emulsion into its components, which can cause slugs of water to be injected throu~h the burner nozzle leadin~ to combustion problems and possible engine damage, an emulsifier or emulsion stabilizer is also desirable in the water/fuel oil emulsion.
Advantageously/ the emulsifier utilized comprises a composition selected from one or more alkan~lamides,: by which ls gene~ally meant an amide formed by condensation o~ an alkyl or hydroxyalkyl amine~ or mixtures thereof r and an organic acid. Pre~erred acids are fatty acids, such as lauric acid, linoleic acid, oleic acld, stearlc acid, and coconut oil ~atty acids. Most pre~erred are alkanolamides having a molar ratio of alkanolamine group to acid group of from about l:l to about 2~
:'' Surprisingly, these compositio~s can stabilize an emulsion of up to about 50% water-in-fuel oil, or up to W~ ~J2/ 1~70 i PCT/US92/03328 2l~sas6 --7-- ~:
abs:~ut 80% fuel oil-in-water in alkanolamid~ amounts as low as about 0.05% by weight, and even as ~ow as about 0.01% ~y weight. In fact, although there is no true :~
maximum amount of emulsifier which can be used, there is usually no need for greater than abou~ 1%, or, in fact, greater than about 0.5% by weight emulsifier in the subject emulsion. Advantageously, to stabilize an --emulsion ~f up to about 50% water-in-fuel oil, the noted :~.
alkanolamides should be included in an amount of ~rom ;~
about 0.1% to about 0.3% by weight~
Suitable alkanolamides which can function to .
stabilize the emulsion of the process of the pr~sent invention include any one or more of the followi~g: :~
cocamide diethanolamine (DEA), lauramide DE~, polyoxyethylene (POE) cocamide, cocamide monoethanolamide (MEA), POE lauramlde DEA, olea.mide DEA, linoleamide DEA, an~ stearamide MEA, as well as mixtures thereof. ~uch alkanolamides are commercially available under trade names such as Clindrol ll~O-0, rrom Clintwood Chemical Company of Chicago, :IIlinois; Schercomid ODA, from Scher ::hemicals, Inc. of: Clifton, New Jersey; Sche~c:omid SO~
also from Scher Chemicals , I:nc .; ~nd Mazamide~, and the Mazamide series from PPG Nazer Products Corp. of Gurnee, Illinois. : : :
Other emulsif iers which: may be useful include :
ethoxylated alkylphenols, such as nonyl~ phenol, octyl phenol, i etc. and salts o~ alkylated sulfates or sulfonates, such ~ as sodium lauryl sulfate. ~ In addit~ion, the skilled artisan will recognize that o~her emulsifiers or blends of emulsifiers, ma~ be also effective at maintaining the stability: of the inventive ~emulsio~
.;, The use of ~ the noted emulsifiers prov1des chemicaI
"
. . .
WOg~/l9701 PCT/US92~03328 ~ 1 0 ~
-8- :
emulsification, which is dependent on hydrophylic-lipophylic balance (HLB), as well as on the chemical nature of the emulsifier. The HLB of an emulsifier is an expression of the balance of the size and strength of the hydrophylic and the lipophylic groups of the composition.
The HLB, which was developed as a guide to emulsifiers by :~
ICI ~mericas, Inc. of Wilmington, Delaware can be determined in a number of ways, most conveniently for the p~rposes of this in~ention by the solubility or dispersibility characteristics of the em~lsifier in water, from no dispersibility (HLB ranye of 1-4) to clear solution (HLB range of 13 or greater). The emulsifiers useful in the present invention should most preferably have an HLB of 8 or less, meaning that after vigorous agi~ation they form a milky dispersion in water ~HLB
range of 6-8~, poor dispersion in water (HLB range of 4~6), or show no dispersability in water (HLB range of less than 4).
It is also possible to utilize a physical emulsion .:
stabilizer in combination with the chemical emulsifiers noted above to maximize the sta~ility of the emulsio~ :
achieved in the process of the present invention. Use of physical stabilizers also provides economlc benefits due to their relatively low cost. Altho~gh not wishing to:be bound by any theo ~, i~ is belie~ed that physical stabilizers increase ~emulsion stability :either by increasing ~he solubility of immiscible phases or by ~orming an insoIuble barrier attracted to the oil~water interface. Exemplary of suitable~ physical stabilizers are ~axes, cellulose products and~gums such as whalen gum and xanthan gum. : ~
~,...
When utilizing both chemical emulsifiers and physical emulsion stabllizPrs, the physical 5tabilizer is present ., WO~ 7nl PCT/US92/033~8 in an amount of about 0.05% to about 5% by weight of the combination ~f chemical emulsifier and the physical stabilizer. The resulting combination emulsifier/stabilizer can then be used at the same levels noted above for the use of emulsifier alone.
The emulsification provided must be sufficient to maintain the emulsion to a greater extent than if the emulsifier was not present and to as great an extent'as possibli. The actual level of emulsification will vary depending upon the percentage of oil and water in the emulsion and the particular fuel oil utilized. ~or example, when the continuous phase is ~2 oil, it is highly desired that no more than about 0.1~ free water be present in the emulsion, and that the emulsion -is maintained that way at ambient conditions for at least about two hours. Ambient conditions, that is, the .
conditions to which the emulsion is expected to be exposed, include the temperature in the gas turbine fuel feed lines. Such temperatures can be~up to about 65C
more typically up to about 90C and even as high as about~
100 C. ~ ' The emulsion used in the pro~ess of the present in~ention can be formed usinq a suitable mechanical emulsifying apparatus which would be familiar to the skilled artisan. Advantageously, the ~apparatus is an in-1ine emulsifying device for most efficiency. The emulsion is. formed by feeding both the water and ~he fuel oil in the desired proportions to the emulsifying ~.
appara~us, and: emulsi~ier or stabilizer ~he~ used~can~
either be admlxed or dispersed in~o one or b~th of ~he components before emulsification or can be added to the emulsion after it is formed.
: : ~
~2~197~1 PCT/U~92/03328 2 1 0 !~ ~ 3 6 Preferably, the emulsifier and/or sta~ilizer is present at the time of emulsifying the water and fuel oil. Most advantageously, any emulsifier or stabilizer used is pro~ided in the water phase, depending on its HLB. It has been found that the emulsions noted above with the chemical emulsifiers can be stabilized at up to about 50~ water-in-fuel oil for up to 30 days and longer. In fact, with mild agitation, such as recirculation, it is believed that th~ emulsic~ can stay in suspension indefinitely.
Surprisingly, the emulsion can then be introduced into a c~mbustion ran of the gas turbine through the fuel feed lines and burner nozzles conventionally used with such combustion apparatus. There lS no need for modification of the gas turbine fuel feed lines or combustion can to accommodate the emulsion used in the process of this invention.
Figures 1 an~ 2 illustrate a gas turbine fuel supply :
system having installed:therein an emulsification system for ~he practice of ~he:process:of the present:invention and a schematic illustration;:of~ the emuls~ification system:
:itself. As illu~.at~d~ in~ Figure l:,~an:~emulsification~
system lO can ~ be installed~ln~;a~ gas~:turbine~fuel supply system lOO between the~ h~eater l22 and~the~final:filter 124~ hough emulsifi~ation:~system~lO~is:illus~ra~ed~as being installed: ~in~ this~pos~ition:in~uel supply ~sys~em~
lOO, it will ~ be recogniz~ed b~y the skilled arti6an~t~at other positions~ may; ;be ~ more~ ~advantaqeous in ~terms of emulsion stability:~ in: ~other :~fuel ~:supply ~ ~;system;~
embodiments, and :emulslfi:catlon : system~: lO~can:~:be installed at virtual~ly any::po~lnt alon~ fuel supply~system~
lOO :for operability.~Indeed~, it~will also be~recogniz~d~
that~ heater ~122 ~and~final~filter 124 are preferr~d: :
., , ' ~ `'' W~Z~1')7~1 P~T/US9~/03328 2~'.`3~3~
components of fuel supply system 100 and conventionally utilized~ but not critically needed.
Fuel supply system 100 is typical of many gas turbine f~el supply syst~ms and generally comprises a fuel supply line 110 which is fed by a fuel tank or other holding or storage apparatus (~ot shown). Fuel flowing through fuel supply line 110 proceeds through a set of initial filters 112a and 112b, and is then fed to individual fuel sup~ly systems 120, 220, and 320 which feed engines controlled by fuel supply system 100. For ease of understanding, fuel supply system 120 which feeds engine manifold 130 is specifically illustrated. Supply systems 2~0 and 320 are equivalent in operation.
Fuel supplied through fuel supply line 110 is fed along engine manifold 130 supply line 120 into heater 122. From there, the fuel flow continues past valve 114 into final filter 124. From ~inal filter 124, the fuel flow continues along line 12~ through engine pump 136 and from there into fuel distribution manifold 121 which then supplles the fuel through primary nozzle 132~ and secondary nozzle 134 to engine manifold 130~ which is the combustion æone of the subject gas turbine. In::addition, fuel supply system 110 further comprises recirculation lines 123a and 123b and recirculation pump 128 for recirculation of the fuel through line 123.
! When valve 114 in fuel supply line 120 i~ closed and val~2s 20 and 22 in ~emulsification system 10 are open, fuel flowing along fuel supply: line 120 is shunted through emulsification system lO after heater 1~2, and lS
resupplied to fuel supply line 120 be~ore final filter 124 ior ieeding to englne manifold 130 or recirculation.
.
~Y~ 7~1 PCT/US9~03328 ~ 0 9~i -12-As illustrated in Figure 2, emulsification system lO
comprises an emulsifier supply line 30 which supplies emulsifier from a tank or other storage means (not shown~
to a metering pump, and is then fed through line 50. In addition, emulsification system lO comprise~ water inlet line 40 which feeds water from a tank or other supply means (not shown) through a water pump 28a to supply line where it is admixed with emulsifier supplied from emulsifier supply line 30.
The water/emulsifier fed through line S0 then meets fuel being fed through line 58 when valve 20 is open and valve 114 is closed, These are then fed through either one or both of l l/2 inch emulsifier S2 or 2 inch emulsifier 54, depending on whether one or both of valves 24 or 26 is open through feed lines 56a and 56b, respectively. The emulsified water-in-fuel oil is then fed via line 58 back through fuel supply line 120 when valYe 22 is open and from there into engine pump 136 and ir:to engine manifold 130~
Although not wishing to be bound by any theory, it is believed that the use o~ an emulsion provides striking a~vantages o~er separate water injection syst~ms because the water is being provided internal ~o the flame. By doing so, less water is required to achieve superior results, which reduces the deleterious effects of directly introducing large amounts of water to the ~ombustion zone of the gas tur~ine~
Because of the advantages of introducing water internal to the flame, utilization of the inventive process r~sults in a redu~ed use of demineralized water (since the emulsion contains less than the l:l ratio of water to fuel oil used when water is injected directly W~J2/1~701 PC~/US92~03328 2 1 0 9 ~ 9 6 ~
into the combustion can), and leads to less thermal stress which reduces maintenance cost and outage time.
When the emulsified fuel is introduced into the combustion zone, the heat of vaporization from the burning fuel causes the emulsified wàter droplets to become stea~, which creates a secondary atomization.
This secondary atomization improves combustion and increases the gas volume. In addition, the heat re~uired to change the water to steam is believed to reduce the flame temperature of the combustlon which helps to rPduce formation of nitrogen oxides.
Additionally, use of the water/fuel oil emulsion results in substantial elimina~ion of the need for an expensive, independent smoXe suppressant additive.
Typically, such additives are heavy metal ~ased products which can form ~eposits on the turbine blades, reducing efficiency and increasing maintenance costs. By the use :
of emulsions in the process of~this invention, a 90% or greater reduction in smoke suppressant additive use is often achieved, which increases ~the blade:life due to reduced depo its, and~ creates~ less wear on:the turbine blade coatings. These:~d~antages~ lead;to signifioant~
:~savin~s in operating and~maint~nan~e cos~s.
Furthermore,~ when ~:compared~ to a ~separate water injectlon system, the~:use of the process of thls inventionl leads to improved engine fuel sys~em integrity;
the en~ine burns cooler,iwhich,~ as~noted~ ads~t`o less~
thermal stress;: it is believ~ed that ~he~gas turbine:can~
assume a ~higher ~:load~capacity;~ ~and compliance~; with environmental regulations is~more~easily ob~ain~b~le.
When the proces5 Of the pres~nt invention is,: for WO'~2/1~7~1 PCr/US9~/0332~
21~90~6 lnstance, conducted on a 48 megawatt gas turbine by installing a manually operated in-line emulsification system at the fuel oil inlet, it is found that reductions of Il~trogen oxides of about 75%, which are immediate and reproducible, are obtained. These results are about 50%
greater than those found when a separate water in~ection system is used at equivalent water injection rates. In addition, plume opacity is found to disappear and no .~
operational problems are detected. In fact, inspection ~-of the engine after use of the emulsion process of this inventiQn shows no deposits. ;
The following examples further illustrate and explain the invention. ~:
~ E~E I
An emulsification system is prepared comprising two rotary emulsifiers and related storage, pumping and piping apparatus for prPparation and supply of a water-in-fuel oil emulsion to a Pratt and Whitney Jet engine burning 30 gaIlons of fuel per minute at full load ..
"
" ~
Baseline emissions tests are run on the engine with~ :
non-emulsified distillate fuel oil, and~ then with ~.
emulsi~ied fuel at water levels:of 10%, 15%, 20%, 25~, :
35~, and 50%. The emulsifier used is oleamide DEA added at 2.5 gallons per l,000 gallons of fuel ~corresponding to .25% of emulsi~ier by weight). The emulsion remained ~:
stable (i.e., no visible water separation~ for over two hours without agitationa ,..
The results of the two tests are then compared and the foIlowing found: :`
W09~197nl PCT/US9~/03328 ~1~9~.i3S
1. When compared to baseline, each incremental increase in water content reduced nitrogen oxides levels up to ~o%.
2. At water rontents above 20%, visible opacity disappeared. ~
Nitrogen oxides are troublesome pollutants and comprise a major irritant in smog. It is further believed that nitrogen oxides can cause or enhance the process known as photochemical smog formation through a series of reactions in the presence of sunlight and hydrocarbons.
Moreover, nitrogen oxides are a significant contributor to acid rain and have been implicated in the undesirable warminy of the atmosphere through what is known as the "greenhouse effect" and in the depletion of the ozone layer. In addition, gas turbines often emit a visible plume, which is highly undesirable since it causes concern among the population in areas surrounding the facility.
Although the use of emulsified oils (primarily produced from relatively simple mechanical technigue~
for combustion improvemen~s has been suggested in the past, they have not:been~applied to gas turbines, and the oils emulsified are usually~ heavy oils (i.e., #5: oilj.
Because gas turbines are peaking units, the fuel is required to remain emulsified for at least 30 days in a holding tank, and at least 2 hours during in-line mixing . This has been dif f icul~ to accomplish, especially when using mechanical emulsion methodology.
In addition, gas turbines are very sensltive to corrosion, which often leads the practitioner to avoid introducing emulsified water into the combustion zone~
~'.
W~ 7~l PCT~US~2/03328 S
It has been known for some time that the injection of wa~er directly into the combustion zone (also referred to as the "combustion can") of a gas turbine at water to fuel ratios of greater than l:l can control the emission of NOX and reduce opacity to a limited extent. The direct injection of water into the combustion can, though, requires extensive mechanical modificatiQn of the gas turbine (with high capital cost) and in~olves thP ::
injection of large volumes of demineralized w~tter which results in ex~ensive additional maintenance and out ye time because of the the~mal shock to the combustion can.
What is desired, therefore, is a process which permits the reductic:~n of effluent nitrogen oxides and plume opacity from a gas turbine wi~hout the thermal ~.
shock, large capital costs, and other drawbacks of ;
injecting water directly .into the combustion can.
Brlef De ~
The present invention will be better understo~d and its ad~antages more apparent in view of the *ollowing .-de~ailed description, especialIy when read with reference to the appended drawings, wherein:
' FIGURE 1 is a schematic~ illu~stration of a gas turbine fu~l supply system :having an emulsification æystem -.
according to the present::invention installed therein;
~ IGU~E 2 is a schematic illustration of an emulsification system according to the present invention as installed in a gas turbine fuel supply system, and ~ -.
FIGURE 3 is a graphic representation of the results of Examples IIa and IIb.
., .
W~ tOI PCr/US92/03328 2 1 ~ 6 Disclosure of Invention The pr~sent in~ention relat~s to a method for reducing nitrogen oxides emissions and improving the combustion efficiency of a gas turbine (which term will be considered to be interchange~ble with ~omb~stion turbine). In particular, this invention relates to a process involving the formation of a stable water-and~
fuel oil emulsion, where the oil is a light fuel oil such as diesel fuel, distillate fuel or ~2 oil. The subject emulsion can be either a water-in-fuel oil or a fuel oil-in-water emulsion (although water-in-fuel oil emulsions ~re preferred for most applications),~and the introduction of the emulsion into at least one of the combustion cans of a gas turbine through its fuel system.
Typically, the oil phase in the inventive emulsions comprise what is conventiona:lly known as diesel fuel, distillate fuel, or #2 oil, as defined by the Amert an Society of Testing and Measurement (ASTM~ Standard Specification for Fuel Oils (~esignation: D 396-86).
Especi~lly preferred are distillate fuels. Included among these are kerosene and ~et ~uels, both commercial and military, commonly referred to as ~P4 and JP5, respectively.
Although demineralized water is n~t re~uired for the suc~essful control of nitrogen oxides and opacity, the use of , demineralized wat~r in the emulsion foxmed accordi~g t~ the process~of this invention is preferred in order to avoid the deposit of minerals from the wa~er on the blades and other iL~ernal surfaces of the gas turbine. In this way, turbine life is extended and maintenance and outage tlme signifi~antly reduced.
~ /lg7~l PC~`/U~92/03328 2~ 09VYij -The emulsions used in the fuel system of the gas turbine advantageously comprise water-in-fuel oil emulsions having up to about 50% w2ter by w ight. The emulsions of this type which have the most practical significance in combustion applications are those having at least abo~t 5% water and are preferably about 10% to about 35% water-in-fuel oil by weight. In addition, this invention also relates to the formation of fuel oil-in-water emulsions having about 50% to about 8b%
water, which have practical applicability in certain situations.
Advantageously, the emulsions are prepared such that the discontinuous phase (i.e., the water in a water-in-fuel-oil emulsion and the oil in an a fuel oil-in-water emulsion) has a particle size wherein at lea~t about 70%
of the droplets are below about 5 microns Sauter mean diameter. More preferably, at least about ~5~, and most pre~erably at least about 90~, are below about 5 microns Sauter mean diameter.
Emulsion stability is largely related ~o droplet si~e. The primary driving force for emulsion separation is the large energy associated with placing oil molecul s in close proximity to water molecules in the form of small droplets. Emulsion breakdown is controlled by how quickly droplets coalesce. Emulsion stabil~ity can be e~han~ed by the u~e of surfa~tants and the like, which ~Ict as ~mulsifiers or emulsidn stabilizers. These generally work by forming repulsiYe layers hetween droplets prohibiting coalescence~ The gravitational driving f orce for phase separatlon is much more pro~inent for large droplets,~ so lemulsions containing large droplets separate mosk rapidly.
W~ 7~)1 P~T/US92/03328 2 l 09~ 6-Smaller droplets also settle, but can be less prone to coalescence, which is the cause of creaming. If droplets are sufficiently small, the force of gravity acting on the droplet is small compar~d to thermal fluctuations or sub~le mechanical agitation forces. In this case ~he emulsion can beoome stable almost indefinitely, although given a long enough period of time or a combination of thermal fluctuations these emulsions ~ill eventually separate~ ' Because of the operating characteristics of gas turbines, ik is requixed that the water/fuel oil emulsion exhibit a high degree of st:ability. In most cases, gas turbines are "peaking" unit:s, as noted,. which do not operate regularly. Accordingly, an emulsified fuel mcy sit stagnant for extended pe.riods or with only mild recirculation in the fuel line. In order to avoid separation of the emulsion into its components, which can cause slugs of water to be injected throu~h the burner nozzle leadin~ to combustion problems and possible engine damage, an emulsifier or emulsion stabilizer is also desirable in the water/fuel oil emulsion.
Advantageously/ the emulsifier utilized comprises a composition selected from one or more alkan~lamides,: by which ls gene~ally meant an amide formed by condensation o~ an alkyl or hydroxyalkyl amine~ or mixtures thereof r and an organic acid. Pre~erred acids are fatty acids, such as lauric acid, linoleic acid, oleic acld, stearlc acid, and coconut oil ~atty acids. Most pre~erred are alkanolamides having a molar ratio of alkanolamine group to acid group of from about l:l to about 2~
:'' Surprisingly, these compositio~s can stabilize an emulsion of up to about 50% water-in-fuel oil, or up to W~ ~J2/ 1~70 i PCT/US92/03328 2l~sas6 --7-- ~:
abs:~ut 80% fuel oil-in-water in alkanolamid~ amounts as low as about 0.05% by weight, and even as ~ow as about 0.01% ~y weight. In fact, although there is no true :~
maximum amount of emulsifier which can be used, there is usually no need for greater than abou~ 1%, or, in fact, greater than about 0.5% by weight emulsifier in the subject emulsion. Advantageously, to stabilize an --emulsion ~f up to about 50% water-in-fuel oil, the noted :~.
alkanolamides should be included in an amount of ~rom ;~
about 0.1% to about 0.3% by weight~
Suitable alkanolamides which can function to .
stabilize the emulsion of the process of the pr~sent invention include any one or more of the followi~g: :~
cocamide diethanolamine (DEA), lauramide DE~, polyoxyethylene (POE) cocamide, cocamide monoethanolamide (MEA), POE lauramlde DEA, olea.mide DEA, linoleamide DEA, an~ stearamide MEA, as well as mixtures thereof. ~uch alkanolamides are commercially available under trade names such as Clindrol ll~O-0, rrom Clintwood Chemical Company of Chicago, :IIlinois; Schercomid ODA, from Scher ::hemicals, Inc. of: Clifton, New Jersey; Sche~c:omid SO~
also from Scher Chemicals , I:nc .; ~nd Mazamide~, and the Mazamide series from PPG Nazer Products Corp. of Gurnee, Illinois. : : :
Other emulsif iers which: may be useful include :
ethoxylated alkylphenols, such as nonyl~ phenol, octyl phenol, i etc. and salts o~ alkylated sulfates or sulfonates, such ~ as sodium lauryl sulfate. ~ In addit~ion, the skilled artisan will recognize that o~her emulsifiers or blends of emulsifiers, ma~ be also effective at maintaining the stability: of the inventive ~emulsio~
.;, The use of ~ the noted emulsifiers prov1des chemicaI
"
. . .
WOg~/l9701 PCT/US92~03328 ~ 1 0 ~
-8- :
emulsification, which is dependent on hydrophylic-lipophylic balance (HLB), as well as on the chemical nature of the emulsifier. The HLB of an emulsifier is an expression of the balance of the size and strength of the hydrophylic and the lipophylic groups of the composition.
The HLB, which was developed as a guide to emulsifiers by :~
ICI ~mericas, Inc. of Wilmington, Delaware can be determined in a number of ways, most conveniently for the p~rposes of this in~ention by the solubility or dispersibility characteristics of the em~lsifier in water, from no dispersibility (HLB ranye of 1-4) to clear solution (HLB range of 13 or greater). The emulsifiers useful in the present invention should most preferably have an HLB of 8 or less, meaning that after vigorous agi~ation they form a milky dispersion in water ~HLB
range of 6-8~, poor dispersion in water (HLB range of 4~6), or show no dispersability in water (HLB range of less than 4).
It is also possible to utilize a physical emulsion .:
stabilizer in combination with the chemical emulsifiers noted above to maximize the sta~ility of the emulsio~ :
achieved in the process of the present invention. Use of physical stabilizers also provides economlc benefits due to their relatively low cost. Altho~gh not wishing to:be bound by any theo ~, i~ is belie~ed that physical stabilizers increase ~emulsion stability :either by increasing ~he solubility of immiscible phases or by ~orming an insoIuble barrier attracted to the oil~water interface. Exemplary of suitable~ physical stabilizers are ~axes, cellulose products and~gums such as whalen gum and xanthan gum. : ~
~,...
When utilizing both chemical emulsifiers and physical emulsion stabllizPrs, the physical 5tabilizer is present ., WO~ 7nl PCT/US92/033~8 in an amount of about 0.05% to about 5% by weight of the combination ~f chemical emulsifier and the physical stabilizer. The resulting combination emulsifier/stabilizer can then be used at the same levels noted above for the use of emulsifier alone.
The emulsification provided must be sufficient to maintain the emulsion to a greater extent than if the emulsifier was not present and to as great an extent'as possibli. The actual level of emulsification will vary depending upon the percentage of oil and water in the emulsion and the particular fuel oil utilized. ~or example, when the continuous phase is ~2 oil, it is highly desired that no more than about 0.1~ free water be present in the emulsion, and that the emulsion -is maintained that way at ambient conditions for at least about two hours. Ambient conditions, that is, the .
conditions to which the emulsion is expected to be exposed, include the temperature in the gas turbine fuel feed lines. Such temperatures can be~up to about 65C
more typically up to about 90C and even as high as about~
100 C. ~ ' The emulsion used in the pro~ess of the present in~ention can be formed usinq a suitable mechanical emulsifying apparatus which would be familiar to the skilled artisan. Advantageously, the ~apparatus is an in-1ine emulsifying device for most efficiency. The emulsion is. formed by feeding both the water and ~he fuel oil in the desired proportions to the emulsifying ~.
appara~us, and: emulsi~ier or stabilizer ~he~ used~can~
either be admlxed or dispersed in~o one or b~th of ~he components before emulsification or can be added to the emulsion after it is formed.
: : ~
~2~197~1 PCT/U~92/03328 2 1 0 !~ ~ 3 6 Preferably, the emulsifier and/or sta~ilizer is present at the time of emulsifying the water and fuel oil. Most advantageously, any emulsifier or stabilizer used is pro~ided in the water phase, depending on its HLB. It has been found that the emulsions noted above with the chemical emulsifiers can be stabilized at up to about 50~ water-in-fuel oil for up to 30 days and longer. In fact, with mild agitation, such as recirculation, it is believed that th~ emulsic~ can stay in suspension indefinitely.
Surprisingly, the emulsion can then be introduced into a c~mbustion ran of the gas turbine through the fuel feed lines and burner nozzles conventionally used with such combustion apparatus. There lS no need for modification of the gas turbine fuel feed lines or combustion can to accommodate the emulsion used in the process of this invention.
Figures 1 an~ 2 illustrate a gas turbine fuel supply :
system having installed:therein an emulsification system for ~he practice of ~he:process:of the present:invention and a schematic illustration;:of~ the emuls~ification system:
:itself. As illu~.at~d~ in~ Figure l:,~an:~emulsification~
system lO can ~ be installed~ln~;a~ gas~:turbine~fuel supply system lOO between the~ h~eater l22 and~the~final:filter 124~ hough emulsifi~ation:~system~lO~is:illus~ra~ed~as being installed: ~in~ this~pos~ition:in~uel supply ~sys~em~
lOO, it will ~ be recogniz~ed b~y the skilled arti6an~t~at other positions~ may; ;be ~ more~ ~advantaqeous in ~terms of emulsion stability:~ in: ~other :~fuel ~:supply ~ ~;system;~
embodiments, and :emulslfi:catlon : system~: lO~can:~:be installed at virtual~ly any::po~lnt alon~ fuel supply~system~
lOO :for operability.~Indeed~, it~will also be~recogniz~d~
that~ heater ~122 ~and~final~filter 124 are preferr~d: :
., , ' ~ `'' W~Z~1')7~1 P~T/US9~/03328 2~'.`3~3~
components of fuel supply system 100 and conventionally utilized~ but not critically needed.
Fuel supply system 100 is typical of many gas turbine f~el supply syst~ms and generally comprises a fuel supply line 110 which is fed by a fuel tank or other holding or storage apparatus (~ot shown). Fuel flowing through fuel supply line 110 proceeds through a set of initial filters 112a and 112b, and is then fed to individual fuel sup~ly systems 120, 220, and 320 which feed engines controlled by fuel supply system 100. For ease of understanding, fuel supply system 120 which feeds engine manifold 130 is specifically illustrated. Supply systems 2~0 and 320 are equivalent in operation.
Fuel supplied through fuel supply line 110 is fed along engine manifold 130 supply line 120 into heater 122. From there, the fuel flow continues past valve 114 into final filter 124. From ~inal filter 124, the fuel flow continues along line 12~ through engine pump 136 and from there into fuel distribution manifold 121 which then supplles the fuel through primary nozzle 132~ and secondary nozzle 134 to engine manifold 130~ which is the combustion æone of the subject gas turbine. In::addition, fuel supply system 110 further comprises recirculation lines 123a and 123b and recirculation pump 128 for recirculation of the fuel through line 123.
! When valve 114 in fuel supply line 120 i~ closed and val~2s 20 and 22 in ~emulsification system 10 are open, fuel flowing along fuel supply: line 120 is shunted through emulsification system lO after heater 1~2, and lS
resupplied to fuel supply line 120 be~ore final filter 124 ior ieeding to englne manifold 130 or recirculation.
.
~Y~ 7~1 PCT/US9~03328 ~ 0 9~i -12-As illustrated in Figure 2, emulsification system lO
comprises an emulsifier supply line 30 which supplies emulsifier from a tank or other storage means (not shown~
to a metering pump, and is then fed through line 50. In addition, emulsification system lO comprise~ water inlet line 40 which feeds water from a tank or other supply means (not shown) through a water pump 28a to supply line where it is admixed with emulsifier supplied from emulsifier supply line 30.
The water/emulsifier fed through line S0 then meets fuel being fed through line 58 when valve 20 is open and valve 114 is closed, These are then fed through either one or both of l l/2 inch emulsifier S2 or 2 inch emulsifier 54, depending on whether one or both of valves 24 or 26 is open through feed lines 56a and 56b, respectively. The emulsified water-in-fuel oil is then fed via line 58 back through fuel supply line 120 when valYe 22 is open and from there into engine pump 136 and ir:to engine manifold 130~
Although not wishing to be bound by any theory, it is believed that the use o~ an emulsion provides striking a~vantages o~er separate water injection syst~ms because the water is being provided internal ~o the flame. By doing so, less water is required to achieve superior results, which reduces the deleterious effects of directly introducing large amounts of water to the ~ombustion zone of the gas tur~ine~
Because of the advantages of introducing water internal to the flame, utilization of the inventive process r~sults in a redu~ed use of demineralized water (since the emulsion contains less than the l:l ratio of water to fuel oil used when water is injected directly W~J2/1~701 PC~/US92~03328 2 1 0 9 ~ 9 6 ~
into the combustion can), and leads to less thermal stress which reduces maintenance cost and outage time.
When the emulsified fuel is introduced into the combustion zone, the heat of vaporization from the burning fuel causes the emulsified wàter droplets to become stea~, which creates a secondary atomization.
This secondary atomization improves combustion and increases the gas volume. In addition, the heat re~uired to change the water to steam is believed to reduce the flame temperature of the combustlon which helps to rPduce formation of nitrogen oxides.
Additionally, use of the water/fuel oil emulsion results in substantial elimina~ion of the need for an expensive, independent smoXe suppressant additive.
Typically, such additives are heavy metal ~ased products which can form ~eposits on the turbine blades, reducing efficiency and increasing maintenance costs. By the use :
of emulsions in the process of~this invention, a 90% or greater reduction in smoke suppressant additive use is often achieved, which increases ~the blade:life due to reduced depo its, and~ creates~ less wear on:the turbine blade coatings. These:~d~antages~ lead;to signifioant~
:~savin~s in operating and~maint~nan~e cos~s.
Furthermore,~ when ~:compared~ to a ~separate water injectlon system, the~:use of the process of thls inventionl leads to improved engine fuel sys~em integrity;
the en~ine burns cooler,iwhich,~ as~noted~ ads~t`o less~
thermal stress;: it is believ~ed that ~he~gas turbine:can~
assume a ~higher ~:load~capacity;~ ~and compliance~; with environmental regulations is~more~easily ob~ain~b~le.
When the proces5 Of the pres~nt invention is,: for WO'~2/1~7~1 PCr/US9~/0332~
21~90~6 lnstance, conducted on a 48 megawatt gas turbine by installing a manually operated in-line emulsification system at the fuel oil inlet, it is found that reductions of Il~trogen oxides of about 75%, which are immediate and reproducible, are obtained. These results are about 50%
greater than those found when a separate water in~ection system is used at equivalent water injection rates. In addition, plume opacity is found to disappear and no .~
operational problems are detected. In fact, inspection ~-of the engine after use of the emulsion process of this inventiQn shows no deposits. ;
The following examples further illustrate and explain the invention. ~:
~ E~E I
An emulsification system is prepared comprising two rotary emulsifiers and related storage, pumping and piping apparatus for prPparation and supply of a water-in-fuel oil emulsion to a Pratt and Whitney Jet engine burning 30 gaIlons of fuel per minute at full load ..
"
" ~
Baseline emissions tests are run on the engine with~ :
non-emulsified distillate fuel oil, and~ then with ~.
emulsi~ied fuel at water levels:of 10%, 15%, 20%, 25~, :
35~, and 50%. The emulsifier used is oleamide DEA added at 2.5 gallons per l,000 gallons of fuel ~corresponding to .25% of emulsi~ier by weight). The emulsion remained ~:
stable (i.e., no visible water separation~ for over two hours without agitationa ,..
The results of the two tests are then compared and the foIlowing found: :`
W09~197nl PCT/US9~/03328 ~1~9~.i3S
1. When compared to baseline, each incremental increase in water content reduced nitrogen oxides levels up to ~o%.
2. At water rontents above 20%, visible opacity disappeared. ~
3. At water levels above 35~, power output frvm the ::
engine increased ~y approximately 3~ due to greater mass flow.
engine increased ~y approximately 3~ due to greater mass flow.
4. Blades and guide vanes are found to be cleaner with the emulsion prepared a~cording to the present invention.
EX~MPLE IIa An emulsification system in a~cordance with Figures 1 and 2 ls prepared fox supply to a single TP~M A4 engine `~
operating as par~ of a twinpac~ rated at approximately 35 MW. Flue gas samples are obtained through a three point ~:
pro~e installed on the outlet ~uct with the sample points~
located between the gulde vanes. The~ samples are combined and the NO and NO2 levels therein measured, and compared with basellne levels.
: Two tests are run usin~ incre~entally increased emulsion strengths (water content) and~ the resul~s plotted in Fi~ure 3.
-EXAMP~ Ib :
~ s reported by ~Becker et al. in "~as Turbine ~ :
Operating Per~ormance a~d Consider~ations for Combi~ne:d Cycle Conversion~ at ~Hay Road Power Station'i, American '.
~' ~, ~' WO~2/l')7()l PCT/US92/0332B
Z ~ U -16-Power Conference, April, lg90, two 100 MW Siemens model V84.2 engines with hybrid burners are operated with :~
separate water injection. Flue gas NO and NO2 leYel~
are measured and compared with baseline levels.
Two tests are run using incrementally increased levels of water injection and the results plotted in ~;~
Figure 3 Figure 3 illustrates the fact that use of the process of the present invention permits equivalent reduc~ion of ni.trogen oxides with approximately 50% of the amount of water injected. ;~
rhe above description is for the purpose of teaching the perso~ of ordinary skill in the axt how to practice the present invention, and it, is not intended to detail all of those obvious modifications and variations of it which will become apparent to the skilled worker upon reading the description. It is intended, however, that all such ob~ious modifications and variatlons be included -~
within the scope of :the present in~ention which is defined ~y the following clalms. ~ .
EX~MPLE IIa An emulsification system in a~cordance with Figures 1 and 2 ls prepared fox supply to a single TP~M A4 engine `~
operating as par~ of a twinpac~ rated at approximately 35 MW. Flue gas samples are obtained through a three point ~:
pro~e installed on the outlet ~uct with the sample points~
located between the gulde vanes. The~ samples are combined and the NO and NO2 levels therein measured, and compared with basellne levels.
: Two tests are run usin~ incre~entally increased emulsion strengths (water content) and~ the resul~s plotted in Fi~ure 3.
-EXAMP~ Ib :
~ s reported by ~Becker et al. in "~as Turbine ~ :
Operating Per~ormance a~d Consider~ations for Combi~ne:d Cycle Conversion~ at ~Hay Road Power Station'i, American '.
~' ~, ~' WO~2/l')7()l PCT/US92/0332B
Z ~ U -16-Power Conference, April, lg90, two 100 MW Siemens model V84.2 engines with hybrid burners are operated with :~
separate water injection. Flue gas NO and NO2 leYel~
are measured and compared with baseline levels.
Two tests are run using incrementally increased levels of water injection and the results plotted in ~;~
Figure 3 Figure 3 illustrates the fact that use of the process of the present invention permits equivalent reduc~ion of ni.trogen oxides with approximately 50% of the amount of water injected. ;~
rhe above description is for the purpose of teaching the perso~ of ordinary skill in the axt how to practice the present invention, and it, is not intended to detail all of those obvious modifications and variations of it which will become apparent to the skilled worker upon reading the description. It is intended, however, that all such ob~ious modifications and variatlons be included -~
within the scope of :the present in~ention which is defined ~y the following clalms. ~ .
Claims (16)
1. A process for reducing nitrogen oxides emissions and improving the efficiency of a gas turbine comprising forming an emulsion which comprises water and fuel oil and using said emulsion in the fuel system of a gas turbine.
2. The process of claim 1 wherein said emulsion comprises a water-in-fuel oil emulsion.
3. The process of claim 2 wherein said emulsion comprises up to about 50% water-in-fuel oil.
4. The process of claim 1 wherein said fuel oil is selected from the group consisting of distillate fuel, kerosene, jet fuel, diesel fuel, and No. 2 oil.
5. The process of claim 3 wherein said emulsion further comprises an emulsifier having an HLB of 8 or less in an amount of about 0.01% to about 1.0% by weight.
6. The process of claim 5 wherein said emulsifier comprises ethoxylated alkylphenols, alkylated sulfates, alkylated sulfonates, or alkanolamides, formed by condensation of an alkyl or hydroxyalkyl amine or mixtures thereof and an acid.
7. The process of claim 6 wherein said alkanolamide emulsifier is selected from the group consisting of cocamide DEA, lauramide DEA, propoxylated cocamide MEA, cocamide MEA, propoxylated lauramide DEA, oleamide DEA, linoleamide DEA, stearamide DEA, and mixtures thereof.
8. The process of claim 7 wherein said alkanolamide emulsifier is present in an amount of about 0.05% to about 0.3% by weight.
9. The process of claim 6 wherein said emulsifier further comprises an emulsion stabilizer selected from the group consisting of waxes, cellulose products, gums J
and mixtures thereof.
and mixtures thereof.
lo. The process of claim 1 wherein said emulsion comprises a fuel oil-in-water emulsion.
11. The process of claim 10 wherein said emulsion comprises about 50% to about 80% water.
12. The process of claim 10 wherein said emulsion further comprises an emulsifier having an HLB of 8 or less in an amount of about 0.01% to about 1.0% by weight.
13. The process of claim 12 wherein said emulsifier comprises an alkanolamide formed by condensation of an alkyl or hydroxyalkyl amine or mixtures thereof and an:
acid.
acid.
14. The process of claim 13 wherein said alkanolamide;
emulsifier is selected from the group consisting of cocamide DEA, lauramide DEA, propoxylated cocamide MEA, cocamide MEA, propoxylated lauramide DEA, oleamide DEA, linoleamide DEA, stearamide DEA, and mixtures thereof.
emulsifier is selected from the group consisting of cocamide DEA, lauramide DEA, propoxylated cocamide MEA, cocamide MEA, propoxylated lauramide DEA, oleamide DEA, linoleamide DEA, stearamide DEA, and mixtures thereof.
15. The process of claim 14 wherein said alkanolamide emulsifier is present in an amount of about 0.05% to about 0.3% by weight.
16. The process of claim 13 wherein said emulsifier further comprises an emulsion stabilizer selected from the group consisting of waxes, cellulose products, gums, and mixtures thereof.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US69155691A | 1991-04-25 | 1991-04-25 | |
| US07/691,556 | 1991-04-25 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2109096A1 true CA2109096A1 (en) | 1992-10-26 |
Family
ID=24777009
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2109096 Abandoned CA2109096A1 (en) | 1991-04-25 | 1992-04-22 | Process for reducing nitrogen oxides emissions and improving the combustion efficiency of a turbine |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0581870A1 (en) |
| AU (1) | AU1900092A (en) |
| CA (1) | CA2109096A1 (en) |
| WO (1) | WO1992019701A1 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5584894A (en) * | 1992-07-22 | 1996-12-17 | Platinum Plus, Inc. | Reduction of nitrogen oxides emissions from vehicular diesel engines |
| EP0924412B1 (en) | 1997-12-17 | 2004-04-14 | ALSTOM Technology Ltd | Method of operating a gas turbo group |
| BR0107632B1 (en) | 2000-01-12 | 2011-09-06 | fuel comprising an emulsion between water and a liquid hydrocarbon, wherein the emulsion is stabilized by a polymeric surfactant. | |
| WO2003006588A1 (en) | 2001-07-09 | 2003-01-23 | Cam Tecnologie S.P.A. | Fuel comprising an emulsion between water and a liquid hydrocarbon |
| CN1622988A (en) | 2002-03-28 | 2005-06-01 | Cam技术股份公司 | Method for reducing emission of pollutants from internal combustion engine, and fuel emulsion comprising water and liquid hydrocarbon |
| ITRM20110694A1 (en) | 2011-12-29 | 2013-06-30 | Fuel S A E | STABILIZED EMULSIONS WITH WATER-EFFECTIVE DIESEL OIL. |
| WO2014158262A1 (en) | 2013-03-14 | 2014-10-02 | Rolls-Royce Corporation | Algae-derived fuel/water emulsion |
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|---|---|---|---|---|
| US2892694A (en) * | 1956-05-22 | 1959-06-30 | Monsanto Chemicals | Process for the manufacture of emulsion fuels |
| US3281438A (en) * | 1962-05-23 | 1966-10-25 | Swift & Co | Water soluble alkylolamides |
| US3339145A (en) * | 1965-04-05 | 1967-08-29 | Ibm | Latching stage for register with automatic resetting |
| US3490237A (en) * | 1966-07-18 | 1970-01-20 | Petrolite Corp | Thixotropic oil-in-water emulsion fuels |
| US3637357A (en) * | 1969-07-23 | 1972-01-25 | Exxon Research Engineering Co | Fuel emulsion with improved stability |
| DE2653026A1 (en) * | 1975-06-30 | 1978-05-24 | Edward C Wenzel | LIQUID MIXTURE THAT CAN BE USED AS FUEL FOR COMBUSTION ENGINES |
| US3932476A (en) * | 1973-07-02 | 1976-01-13 | Ethyl Corporation | Preparation of fatty acid amides |
| KR780000630B1 (en) * | 1975-12-31 | 1978-12-09 | Eun Bok Lee | Method of emulsifing water and buncker c oil |
| US4017522A (en) * | 1976-03-15 | 1977-04-12 | The United States Of America As Represented By The Secretary Of Agriculture | N-(furoyloxyethyl) fatty acid amides |
| US4392865A (en) * | 1977-02-23 | 1983-07-12 | Lanko, Inc. | Hydrocarbon-water fuels, emulsions, slurries and other particulate mixtures |
| JPS544905A (en) * | 1977-06-14 | 1979-01-16 | Kao Corp | Surface active agent for emulsion fuel |
| IL54937A0 (en) * | 1977-07-25 | 1978-08-31 | Gen Electric | Water injection for gas turbine engine emission control |
| US4162143A (en) * | 1978-03-13 | 1979-07-24 | Ici Americas Inc. | Emulsifier blend and aqueous fuel oil emulsions |
| US4199326A (en) * | 1978-03-23 | 1980-04-22 | Fung Paul S T | Emulsified fuel composition and surfactant useful therein |
| US4173455A (en) * | 1978-10-11 | 1979-11-06 | The United States Of America As Represented By The Secretary Of The Army | Fire-safe hydrocarbon fuels |
| DE2854540A1 (en) * | 1978-12-16 | 1980-06-26 | Bayer Ag | FUELS |
| US4666457A (en) * | 1984-09-24 | 1987-05-19 | Petroleum Fermentations N.V. | Method for reducing emissions utilizing pre-atomized fuels |
| CS253476B1 (en) * | 1985-07-16 | 1987-11-12 | Jaroslav Vitovec | Method of phtalic anhydride vapours' continuous desublimation |
| FR2588012B1 (en) * | 1985-10-01 | 1988-01-08 | Sodecim | PROCESS FOR HOMOGENEIZING A MIXTURE OF AQUEOUS RESIDUAL LIQUIDS AND LIQUID OR SOLID FUELS |
| US4725287A (en) * | 1986-11-24 | 1988-02-16 | Canadian Occidental Petroleum, Ltd. | Preparation of stable crude oil transport emulsions |
| US4907368A (en) * | 1987-11-23 | 1990-03-13 | Atlas Powder Company | Stable fluid systems for preparing high density explosive compositions |
-
1992
- 1992-04-22 EP EP92911684A patent/EP0581870A1/en not_active Withdrawn
- 1992-04-22 WO PCT/US1992/003328 patent/WO1992019701A1/en not_active Application Discontinuation
- 1992-04-22 CA CA 2109096 patent/CA2109096A1/en not_active Abandoned
- 1992-04-22 AU AU19000/92A patent/AU1900092A/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| EP0581870A1 (en) | 1994-02-09 |
| AU1900092A (en) | 1992-12-21 |
| EP0581870A4 (en) | 1994-04-27 |
| WO1992019701A1 (en) | 1992-11-12 |
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| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |