CA1149163A - Combustion of ammonia with hydrogen carrier - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
The present invention provides a method of improving the combustion of ammonia, which comprises; mixing in said ammonia from 0.5 to 15 percent by weight of a hydrogen carrier; and com-busting the resulting mixture; said hydrogen carrier being a com-pound selected from the group consisting of a boron hydride, a borohydride, a hydrazine and mixtures thereof, said compound having a molecular weight of from 8 to about 125 and a heat of formation of from about 10 kcal, to about 100 kcal. per mole; provided that the compound selected is non-reactive with the ammonia it is mixed in at ambient temperatures, does not lower the shelf life of the mixture, does not deteriorate below the ignition temperature of said mixture to release energy and at the point of ignition, re-leases energy and hydrogen, said mixture being non-hypergolic.

Description

~9~L~ii3 The invention relates to novel fuel compositions and their use and more particularly concerns methods of improving the combustion of fuels such as ammonia, petroleum distillates, al-coho~s and amines by release of energy and hydrogen at the time of ignition.
This application is a divisional application of copend-ing application No. 280,622 filed June 15, 1977.
It is vital that new sources of high energy fuels be developed and that presently available substandard fuels be im-proved to raise their usefulness and efficiency. Prior hereto,it was appreciated that ammonia, petroleum distillates such as naphtha, benzene and the like, volatile alcohols andamines were fuels which upon combustion form combustion gases with considera-bly greater thermal energy than the initial combustion reactants.
However, each of the above mentioned fuels has failed to achieve an important commercial position as an energy source. As fuels, ammonia, certain of the petroleum distillates, volatile alcohols ~ and amines have shortcomings which can very generall~ be said to - relate to an unsatisfactory combustion. The reàsons for the unsatisfactory combustion are varied and individual to the ~ L63 partlcular fuel as will be dcscri.~ed in grea~er detail hereinaf~er, ' There is agreemcnt among those who are ~no~ledgeable in tl-e ield of energy fuels that hydrogen is the ideal fuel of the future, but that it will be decades be~ore engineering has been developcd to n-eet the practical requi.rements for uti}.ization of hydrogen per se as a commercially significant fuel. l`h~ desirability o utilizing hydrogen as a ~uel is based on thrce factors. First, hydroyen can be produced in abundance from ~ibundant and inexpensive raw ma~erials.
Second, as a sourco of enerc3y, hydrogen prov.ides 61,000 BTU/
pound upon combustion and third, tl~e product o hydrogen co~ustion is wa~er, whicl poses no pollution threat to the ecology.
; To enhance the con~ustion o a number of conventional uels and fuels of poor combustibility, it h~s been previously 6uggested to add gaseous hydrogen to the combustion mix~ure, The addition of hydrogen to combustion m.ixtures can provide additional thermal energ~ release, lower ignition temperature~, advance flame speeds, reduce thë undesirable emissions of nitrogen oxides and carbon monoxide and generally effect a more e~ficient combustion. I-Iowever, the previously proposed methods o adding hydrogen to combustion mixtures haveconsisted of adding yaseous hydrogen to the volatiIized fuel at the time . ~ 3 .
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1~ , ~ ;3 o~ i~nition or just ~rior thercto; ~ee for example U 5.
Patcnt RE 2S,~47, The system~ proposed here~oo.rc ~or injecting ga6eous llydrogen into a com~ustion mi~ture have . been complex, costly and of questionahle reliability, Xn S general, the prior sy6tems ha~e required such things as a i separate hydrogen injecti.on sys~em, includ.ing dual fuel supply lines;.provision for ~eneration and/or storage of hydxogcn ~as and new carburetion control systems and Iike complicated ap~aratus. ~s of this time, no commercial , hydrogell ~as utilizing system has been availahle because o the techllical problems involved in meeting these requirement~
. B~ the method-of my invention, hydrogen is made :~ available to the combustlon mi~ure by dissolving a hydxogen - carrier in the base fuel to obta.in novel fuel com~ositions. .
-LS The carxier releases hydxoyen for combustion at the time of ignition and thus obviates tlle need ~or a separate hydrogen ~as injection s~stem, dual fuel supply system, special carburetion devices, fuel mixing controls and hydrogen ~as xe-leasing ~ genexating and stoxage equipment. The fuel compositions of my invention are also advantageous in that the hydrogen caxxier employe.d is a chemical compound which - has chemically bound hydxogen. The release of hydrogen from the carriex occurs when the chemical bond is broXen with a conseq~ent release o energy. This encrgy release serves as 1 ' I
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.11 ~ 3 an "ener~y kick" to a~sist ic3ni~ion and boo~ combu~tion o~ th~ base fuel and the a~ditive.
It was p~eviously appre~iated that ammon~a in admixturc with air forms an cxplosive fuel mixture which can operate internal con~ustion engin~6. ~Iowever, ammonia ha~ been considered inferior to hydrocarbons as a fuei hecau~e it has a relatively high i~kion temperature in admixture wlth air, i.eOS on the order of ~bout 780~C~
~urtllermore, the cxplosive range of amlnonia and air n~xture ) ls quite narrow, i e.; within a range of about 16 to ~5%
weight of anhydxous ammonia in admixture with air. This requires se~lsitive carburetors. ~lso the higher temperatures re~uire different alloys and designs for the engine, Illustrative of prio~ art attempts to obtain a satisfactory fucl composition based on ammonia is U. S.
Patent No. 2,559,605 which discloses the addition of an auxiliary gas to prime the explosion of a mixture of alr `
and ammonia. Representative of the auxiliary gases di~closed are hydrocarbon gases, carbon monoxide, methanol vapors, 3 methylether, ethylether, methylamine, ethylamine or a mixture o~ such gases~ In U. S~ Patent No. 2,393,S94 an attempt was made to upgrade ammonia as a fuel for use in internal combustion engines by dissolving ammonium nitrate (as an oxldlzer) in liquid ammonia. The latter patent also discloses .,, ' .' ', , .
~ ~ 5 _ . ' '. .

~ 9~63 fuel mlx~ure~ of ~mmonia and low moleeular weight alcohol~
with ammonlum nitrate dissolved therein ~no~hcr approach .
is representecl by U. ~. Pat~nt No 2,140,254 which disclo~es -a device employi.ng fuel mixtures for internal co~bustion engines comprisillg mixturcs of ammollia with hydrogcn gas and nitrogen ~as Other ap~roaches to the use o ammonia a~
a fuel have .included it~ a~l.ixture with hydrocarbon uels ~or use in internal combustion eng:ines (see for example U. S.
Patent Nos~ 1,589,885; 1,671jl58; and 3,150,645).- Compositio~s of ammonla and at least 30jO by weight of lithium ~orohydride are disclosed in U S. Patent 3,108,431 as roc~et fuels, ie ;
fuels possessing hypergolicity.
Although it was previously known that certain boro-hydrides formed mono, di, tri and tetra-ammoniates (UO S.
Patent No. 3,108,431) and that certain boron compounds were advantageously used in a~mixture with liquid hydrocarbon fuels (see for example U, S. Patent Nos. 30738,819; 3,403,014;
3,215,740) it was not heretofoxe appreciated t~at minor propor~ions of these compounds could be employed to prime and enhance the combustion of ammonia-air mixtùres.
In ~eneral, all of the prior art compositions and .
methods of employing ammonia as a fuel have not been entirely satisfactory for a number of reasons, such as, for example, the difficulty in emDloying a rela~ively pure ammonia and .,, ' , ` `, ,.
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F ' '(.li ~ 63 obtaining thc necessary lligh initial.heat fl~sh to bring .
about an auto-ign~tion. No commerclal application ever resulted from such attempts.
The improvements of petroleum distillates such as ga301ine as a fuel, by the addition of from 4 to 10% by weigh-t of hydro~en gas to the vapors of gasoline has been ~uggested; see, for example, ChPmical and Engineering News, ~pril 14, 1975, page l9. The benefits sugyested include a reduction o nitrogen oxide e~issiol~S and carbon monoxide ~ ~
emissions due to the.lower igni.tion temperatures associated . . .
with the mixtures. However, as discussed above, the dificulty of using hydrogen gas heretofore for ~ts fuel potential, particularly as a motor fuel resides in the engineering problems of storing, transporting and adapting it to the automoblle engine. These difficulties are overcome by the method of my invent~on. The addition of ammonia to improve hydrocarbon fuels is disclosed in U. S~ patents ~os~
1,589,885 and ~,671,158~ . . . ;~
Quaternary ammonium boxohydxides are disclosed in U. S~
Patent No. 3,403,014 as useful when added to high volatilit~ ;
gasoline (~eid vapor pressura ~bove ~) in proportions of ~rom 0.001 to 0.1% by weight o the gasoline, as a cold weather anti-stalling additive .
Curxe~t intexest in substitutes or petroleum basea fuels has included the lvwer molecular welght, volatile .
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,-11 ' 1:149163 alcoh ~ ~uch a~ metll~nol, eLhunol and t-butanol wllich c~
be synthesized without resort ~o petroleum ~tarting material~D
Methanol has been thoroughly studied ~ a fuel (~ee ~or .
example Reed et al., Science 182, No~ 4119, page 1299), The advantage of using methanol as a base fuel is related to its ' high octane rating, the lower combustion temperatures wi.th consequent lower exhaust temperatures, lower emissions o ', nitrogen oxid~ and improved comkustion of mixtures o~ ..
gasoline with up to 15% by weight of methanol.~
There are, l~owever, disadvan~ages associated with the use of methanol, alone or i~ admixture wi~h gasoline as a ' . ' fuel~ For e'xample, methanol may require heating to volatil;.æe~
In addition, methanol has a low flame speed, corrodes engine parts (through aldehyde and acid formation) and lowers mileage per gallon (by a factor of 0~5) beca~se of its lower energy .
value (in comparison to gasoline3. By the method o~ my . ;:
i~vention, methanol as a ~uel'may be upgraded in that . .
combustion efficiency is improved, ~lame speed'i~ increased~' corrosion lnhibited and the mile6 per yallon ratio in proved.

Summary o the Invention ~ ' . .

The invention comprises a method o improving the combustion'.o a base ~uel 6elected ~rom tha group consisting of ammonia, petroleum distillates, alcohols having i to 16 . ' , , ''' ,.

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cal-~on atoms, inclusive and a rnolcular weigllt of from 17 to 275 and organic amines havlng a molecular weigh~ o~ ~rom ~bout 17 to about 110, ~hich comprises; mixing in said base fuel from O.S to 15% ~y weight of a hyd~ogen carrier; and combusting the resulting mixture; said hyc~royen carrier being a compound of hydrogen and at least one element selec~ed fxom ~he group consisting of litllium, sodium, po~assium, magnesium, boron, aluminum and nitrogen~ said compound havin~ a molecular weight of fxom 8 to a]~out 125, a he~t of formation o rom about 10 , Xcal. to about 100 kcal. per mole and compatibili~y wit~
the ~6e fuel selected, at ambient temperatures.
The term "ambie~t temperatures" as used herein mean~
a temperature within the range of about minus 20F. to abou~
250F. , The invention also comprises novel fuel compositions which comprise from 0.5% to 15% by weight of a compound of hydro-gen and one or more elements sélected from the group consisting of lithium, sodium, potassium9 aluminum, magnesium~ boron and nitrogen, said compound having a molecular weight of from 8 to 125 and a heat of formation of from about ~0 kcal. to about 100 kcal. pex mole; mixed i~ a base fuel ~e~ected from the group consisting of ammonia, petroleum distillates~ alcohols having from 1 to 16 carbon atoms, inclusive and a molecular weigh~

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__ _. _ . ' r .: - , , . r ~ " 11 ~ 3 . ,. , o from 32 to about 275 and or~anic amines having a molecular weight of from 31 ~o about 110; provided that the compound selected i~ non~reactive with the ba~e fuel ; lt is mixed in at arnbient temperatures,doe~ not lowex S the shelf li.e of the base fuel, does not de~erioL^ate below tlle i~nition temperature o~ said fuel composition to release energy and at the point o~ ignLtion, release~
energy and hydrogen, said fuel composition being non-hypergolic~ ;
O The term "non-hypergolic" is used he~ein in its usual sense as meani.ng the composition is not ordinarily spontan~ously combustible, when in contact with an oxidizer.
The composition6 of the invention are paL-ticularly . ;useful fuels ~or internal combustion engines, turbine ~. ~ .
engines! turbine jet engines and for combustion in conventional sFace heating apparatus~

Detailed Description of the Invention r : ¦

The method of the invention ~s carried out by irst mixing from 0.5 to 15% by weight of the hydrogen carrier in ~ .
~0 the seleated liquld base ueI. ~ixing may be e~fected ~y :
bringing the components o the novel composit.~on togethe~
a~ ambient temperatures and admixing with the aid o~
. ~onventional and appropriate mixing equipment-. The novel : :' ' ' ,~ . . , ' . ' , ' .
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fuel compo~itions so ohtalned are then iynlted in conven~lo~al furnaces, lnternal combustion engines, turbine englnes and like energy utilizing apparatu~ appropL-iat~ ~oi~ the desired combustion and use of the fuel compo6itions~
The base uels employed in the method of the inven~ion a~e well known material~ charac~erized in part a~ l~quids wh~ch are largely volatile at ambient tempexatures. ~ore particula~ly, ammonia may ~e employed in its li~uid form as a base uel or in combination wi~h the other fuels such as ';
0 alcohols, aminefi and/or hydrocarbons in the ~thod of the : -invention. slmilarly, saturated and unsaturated alcohols hav~ng from 1 to 16 car~on atoms, inclusive, may be used as base uels~ SUch alcohols are well known, and may be illustrated by the aliphatic alcohols ~uch a5 methanol, ethanol, n-propanol, isopropanol, n~butanol, t-butanol, n-pentanol, : isopentanol, hexanol, heptanol~ octanol, decanol, hexaaecanol and the like. The cycloaliphatic alcohols such as c~clohexanol may also be employed. Unsaturated aliphatic alcohols ~uch as 1-buten-4-ol, and the like are also representative Oæ ;-;
~0 useful base fuels employed in the method o the invention.
It is realized that many chemical compouhds falling within the classificatlons stated are useful but only limit number po~sessès e~onomical vlrtue.

, . ' , ~ , , .. .. --~ 9~3 Petroleum dis~illate baee fuels a~ defined as the products of rac~iol~al d.istillation of pe~roleum and lnclude for example petro~.eum ether ~the pen~ane-~lexane-heptane low boi.ling mix-ture); gasoline (the heptane to do~e-can~ mixture); kerosene ~the decane to hexadecane mixture) : (to 16 caxbons) benzene, naphth~, toluene, n-hexane and like distillates (the kerosenes and addi~ives mos~ use~ul for jet engines). . ;
Organic amines which may be employed as b~se fuel~ .
O . in the method o the invention axe represente~ by methyl-amine, dimethylamine, diethylamine, triethylami~e, aniline, cyclohe~ylamil~e, and the like.
Preerred as the base fuel according to the invention are ammonia, certain lower aliphatic amines ~see a~ove) L5 and aliphatic alcohol~, particularly ~e~hanol, ethanol and t-butyl alcohol, by themselves, in mixturls of these with - ~r without hydrocarbon aamixturesO - .~
The h~drogen carriers employed aB com~orients of the ~.
compositions of the invention may be characterized as organic ' and inorganic compounds having a high energy content, i.e.;
a positive heat o ormation of from 10 kcalv to about 100 kcal. per mole and are combustible. In addition, ~he hydrogen carriers employed a~e soluble or misci~le (emulsifiable) in the base uels with ~hich they are co~bined, .. . ' '` " , " ' -' ' `~ `.' `''`.
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at a~bient ~emperature~ Thos~ 6kllled in the art will ' .
.. appreciate that the hydroge~ carrlerS selected for compounding .
with a.particular ~ase fuel mu~t also ~e inert in ~espect ~o .
. chemical reaction therewith unde~ ordinary and ambient i temperature condi~ions. B~ i~ext, we mean that the hydro~en ' carrler~ are ~able'and non-reactive with the ~ase fuel under ordinary storage collditions a~ld do not adversely affect the . s~lel-lifa of the base fuel. The hydrogell carrier rnU6~ ;
. release its energy and decompose at or jus~ under the lQ ignition temperature o~ the compo6itions o the lnven~.ion' so that energy and hydrogen are released or combustion .
at the time of ignition. The hydrogen carrier must ~e carefully ~elected to meet the conditions outlined above, . ' for each particular base fuel to ~e compounded therewith~
Ammonia as Base Fuel . .,~ .- . , .
. . The preferred ammonia based fuel compositions of tho " .
invention may be prepared by admixture of liquid ammcnia with .
: a hyarogen carrier compcund Preferred hydro~en carriers to be.
. added to ammonia fuel are tho~e selected from a boron hydride, a ~orohydride, a hydrazine including a lower aliphatic or .
' aromatic~by themselves ox ~y co~bination with each othe~
in the proportions set forth above. Admixture of the fuel composition componen~s i~ conveniently carried out at ambient ¦! temLer res e Flcying onventional ecuipnen~. ~ltbougb ` . . ' " ._.... " - i3 -'. " ' ' . ' "' ~ 9~3 the a~lonia compon~nt may be aclmixed in itB ga~ou~ orm, the admixture i8 pxeercibly carried out wi~h ammonl~ in it~ liquid state undar refr~geration and/or supex~a~mo~phexic pressure, preferably anhydrous ammonia ls used ae t~le base ~uel. Also,. ammonia dissolved in an organic solven~ whi.ch ;
per ~e i~ a combu~tib3.e ma~erial.
~ ny boron or borohydri.de compound may be employed as ~ hydrogen carrier component o the ammonia ~a~e ~uel composition of the.invention, which i~ characterized by its ability to release ener~y and be oxidized ~eadily, Representative of boron and borohydrides employed in p~epari~g the ammonia base fuel compositions of the invenkion are oxganic and inorganic boron hydrides ~uch a~, for example, diboranb~
pentaborane, borazine, boraæol and inorganic ~oxoh~drides:
metal borohydrides ~uch as lithium borohydride~ lithium cyanoborohydride, aluminum borohyride, and the like, adducts of metal borohydrides and organic polynitrogen compound~ .
~uch as those disclosed in U. ~ .Patent No. 3,.3~2,B14 and hav;ng the formula~ .

, . I~ , IM (BH~) X 1 rl ` ,,;

(II) .
wherein ~ i~ an organic nit~ogen compound composed ~oi21~ -of car~on hydrogen and nitrogen atoms, said organi~ nitrogen ,`
compoulld containing at least 1 ni~rogen atom coordinatel~
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Y bonded to M where M repr~sents alu~inum; wlierein x ~8 the , ~alenc~ o~ M alld wherein N i~ an intcg~r havi~g a min.~mum . .
... , value of l and ~ maximum valuo no greater than the number :.: of nitrogen a~oms contained in the organic nitrogen compound , .
,~" L whlch funct'ion as Lewi~ basesî with ~he pro~iso that when,M . ' .
,, is alumlnum then ~ cannot be ~2NZ'wherein each ~ ia a :; monovalent ~aturated hydrocarbon raaical, and wherein Z ~6 -' ' ,,,, hydro~en o'r a monovalent saturated hydrocarbon radica~ .
,~.; Qrganic ~orohy~x~ides such a~ sodium ~riethylbo~ohydride, . , ~,, O 60dium trimetho~yborohydride, cetyltrimethylammoniumborohydride, .. , tetraethylammoniumborohydride, tricaprylmethylammo~lumborohydrid ,,.. r, . triphenylpho'~phineborane and the like hydrazonium borohydride~ , :;.~, such as those disclosed in U., S. Patent N0, ~,215,740 and ' havin~ the general formul;

S 5 l ~ [ I "
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. wherein R', R", and R"' ara alkyl and ~"" and R'R axe tha r;
:. sam~ or different and a~e ~elected from the clas~ consisting.
.. o~ hydrogen and alkyl;-and ~ike hydrazonium borohydridesO ' , Hydrazina compounds employed as hydrogen carriers ~n .
~ ~he preparatlon of ammonia base fuel compositions are .
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~ i3 rcpresented ~ hydraz~ne, monoalkyl ~ubstitutad hydrazine~ ' . such ~s monomethylllydrazine and the like; unsymmetrical v;
- aialkylhydrazlnes ~uch as unsymme~xical dimethylhydrai~ina :.
and the l.ike; symme~rical dial.kylhydrazineis such as fo~ ..
. example ~ymmetrical dlethylhydxazine, ~rialkyl ~ubstituted . hydrazines such ~s or example trimethylhydrazine and tet~aalkyl su~stituted hydrazines ~uch ai3 for example, .
. tetrameth~ll?ydraziine, aromatic hydrazines ~uch a~ pheny~- ;
.. hydrazine and the like, . ~-. Representative o~ other hy~.rogen ca~ier~ ~hich may .
be compounded with ammonia to provide compositions of the ..
.. invention are sodium amide, potassium amide, boronhydride, llthium borohydride, ~odium borohydride and the ~ike.. ; ..
Preferred hydrogen carriers in the method o~ the . invention and fox ammonia based fuel compositio~s ~re the compounds wherein the element compounded with hydrogen i~ ..
. one or more of lithium, sodium, potas6ium, ~oron or nitrogen~
.. ~ ~xemplary of ~uch hydrogen calrier~ are: ~-` ; - ', . (a) hydroxylamine, . ..
.; . ~ iminoalcohol5, like ~-(2-hydroxy-e~hyl? _ .~. - ethylene imine. .
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( ~1 , ~9~63 ~c) hydrazin~s i.ncluding a~kyl ~ ituted . .
hydrazine~ as repre~ented by hydra~ine, hydr~zlne hydrate~ `
methylhydrazine, ~ymmetrical aimothylh~drazln~, unsymmetxical dimcth~lhydrazine, phenylhydrazine, butylhydxazine, S hex~lhydraz.ine and the ~ike; s . .
(~ boxanes ~Uch as diborane, pentaborane, borazil-~
and the like; ' .
. (e) borohydrides such as ll~hium borohydride, .
magnesium borohydride and the like: : !
(~) borane-amine complexes such a~ bo~ane-tert- :.
butylamine, borane ~ dimethylamine, borane ~riethy~amine, borane trimethylamine~ borane . ~yridine, ammonia ^ hydrazine-decaborane adduct (U~ S. Patent 3,291,662), hydrazine , ............. . . . .
diborane 3,323,878), hydrazine P tetraborane, hydrazine ;L5 pentaboxane, trihydrazine D decaborane, dimonomethylhydrazine ~
pentaborane, tximonomethylhydrazine , pentaborane, methylhydraz-ine ~ decabo~ane, dimethylhydrazlne P decabo~ane~ hyarazine-b~s-borane, hydxa~ino~bi~-borane, dimethylhydrazine-bis~ .
. borane (U. S. patent 3,450,638), diammoniate diboxane 0 (U~ S. Patent 3,576,609~ and the like; -(g) hydrazinoalkanols such as ~-hydrazinoethanol . and the liXe, and (h) borohydride-ammonia adducts ~uch as lithium ~ borohydride monoammoniate (U. 5. Patent 3~108,431~ and ,: 2 $ the like . ' ~ -`," ' .., , , ,,'' '''..`.
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( _ .................... , ,~ , , ~__ ~et~olcum J~ifJti~ e~ na~e Fllel .,. __ _ . ________ _ In y~nexal, ~l~e p~trole~lm distillate ~aso uel~
ma~ be im~rovcd by the met.l~od of the invention by admixing one or more of the same hydrogen carrier~ descxibed above in relation ~o ammonia as a bas~ fuel, Pree~ed a~ the hydro~en carrier~ in ~ixturQ with pe~roleum di~tilla~e~
are hydrazines, cspeclally alkyl hydraz~ne~ such ag unsymmetrical dimethylhydrazine, boron-hydrogen adducts .
like ~amine~ BH3 or highel homolog~les~ One o~ the signi~lcant improvements resulting from the pre6ence o~ the add.itive6 described herein relntes to 6igni~icant reduction of undesirable em;.ssion components. Al60 combu~tion efficiency is increased. .
~lcohols as a Ba6e Fuel L5 Those ~k~lled in the art will apprecia~e that the ; - ~eac~ivity of alcohols with ~abile hydrogen llmits the additive hydrogen carriex components ~hich may bo compounded with them. In general, the carrier compoun~s de~cr~bed above ;
in relation-to the improvement of ammonia a~ a ~ase fuel may - ~o be used, provided they are non-~eactive with the alcohol~
Representative of prefèrred hydrogen carrie~ employed as components of the novel composition~ of ~he invention employin~
alcohols as a base fuèl are the hydrazines described in group i (c) above and the borane-amine complexe~ described in (~) ~$ above, proyided they are non-reac~ive ~ith the ~lcohol an~
with water.
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,_ ;3 ; Organic Amines s the Base Fuel A broad range of hydrogen carrier compounds may be admixed with organic amine base fuels to improve their combustion.
In general, all of the aforementioned carrier compounds may be used. Preferred carri.ers for admixture with organic amlne base fuels are the boronhydrides lgrouP (e) above~, the hydrazines [group ~c) above] and the borane . aminecomplexes [group (f) above).
The base fuels described above may also be used in ad-mixture with one another~ For example, ammonia maybe dissolved in the amine fuel and serve as a solvent for the hydrogen carrier ~hich in this case advantageously may be represented by unsym-metrical dimethyl hydrazine or one of the amine-borane adducts.
As a further example, kerosene and an amine fuel such as triethyl ~- amine may be admixed with an amine - BH3 adduct as the hydrogen carrier such as, for example, an amineborohydride aduct (amine-borane) as a hydrogen carrier. A preferred hydrogen carrier for use in such a mixture of base fuels is the adduct of equimolar proportions of ammonia and one-half B2H6: (NH3 . BH3) or a methylamine or ethylamine - BH3 adduct; i.e.; CH3NH2 . BH3;
(C H ) NH2 BH3; (C2H5)2 NH BH3; ~C2H5)3 3 ponding hydrazine adducts like ~CH)2 NNH2 . BH3.
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~ 3 ,'' . . ' ' . ' '.1 In a preferxed e~odimont of the invention, ~he ]Iydroyen carrier is ~ hydrate ~uch a~, for example, - ~!;;
hydrazine hydrate (N2~15b~) or a h~drazillo alcoho~. Xn this manner, oxygen as well as steam are contributed to the ig~ition and combustion process. ; ;
In another preferred el~odimen~ o~ the invention, ~he hydxogen carrler is an amino-alcohol, like N-hydroxy-ethyl-eth`yle~e imine. Such novel composition~ have the f~rt'ller advantage of improving combustion e~ficiency and lowering the emission of noxious by-products.
The base fuels descrîbed above may also ~e used in admixture with one another. ~or e~ample, ammonia may be di~solved in methanol and ~oth ~ay serve a~ ~olvent fo~ the hydrogen carrier which in this case advantageously may be represented by unsymmetrical dimethyl hydraziné, or R stable aminoborane t"stable" meanin~ unreact~ve or very slowly . , , . . , ' reactive with the alcohol ~ase ~uel i~ the particula~ ure of alcohol and ammonia emplo~ed), As a further example, kerosene and an amine fuèl such a~ trie~hylamine; hydrogen car~iers such ~S, fo~ example, an aminoborane ~dduct as a hydrogen carrier A preferred ~drogen carrier for use in such a mi~ture o~ base ~uels is the adauct o~ equimolar propor ons oP ammDAia and bo~o~ly~ide, . , " ''. . ' .. ';'.

. ' ' , . ; ~,.

.. . . .. .. .
. , . . . , . _ .. . ... _ _ ` ~ 63 .................. In addition to ~e hyd~ogon car~ier, the compos~.~i.on~
. - of ~he ~nvention may al~o con~airl ot~e~ Rdditives having . specific d~sired ~unctions~ For examp~e, combustion depo~i~
modifiers such as clays may ~e added to the compositions o~
the invention ~nti-oxidants, ~etal deactivà~ors~ corrosion .
inhibitor~, anti-icing agent~, detergent~, dye~ bricant~
. and ~ike conventional fuel additives may be added to the fuel ~ compos~kion5 of the invention in conventiona~ propor~ions to .
effect their particular purposes upon combustion of the ' ~0 composition of the invention. . -The compositions of the in~entio~ may ~e combusted .
~. . in conventional combustion e~uipment or the e~uipmen~ may be :: . modified to meet the 6~ècial propexties o an individual composition to obtain maximum efficiency, i.e,~ compression !5 xatios, cycle timing, air mixtures, pump mean~ or controlling ~` the 10w of fuel, combustion timing ~echanisms, and like , . control device~ may be modified to meet the ~pecific .
.~ . combustion characteristics o~ the-fuels provided by ~he ,., . . , . ..
method o~ this in~ention~ Tho~e skllled in the ar~ wi.ll ~ 2a . apprecia~e how to effect the desired and advanta~eous :; . modiication~ when ~equired or ~aximum fuel e~iciencyO
;` The ammonia and alcohol based fuels are particularly .
: . advantageous ~uels for tur~ine and internal co~bustion enginesa For example~ tha alcohol and ammonia ~ased fuel composition~ o~ the invention may be employed in internal ., . ', ' '. ' '`, - ' ~', .
." , , . ': . ' :~: . ~ 21 ~ ~;J
`~;' ~ _ ~ 63 combustion en~ines using apparatus and ~ccllniques prevlously . ~nown, Illustratively, t~le composi~ions o the invention may be stored and dcliv~red to carburetor o the internal . combustion engin~ described in U. S. Patent ~o. ~,559,~05.
The liquid rnixtures upon reaching the carburetox nra ,, volatilized and admixed with air before being drawn into .
: the combustion chambers of tha engine. Although it is .
pre~erred'that the mixture of ammonia based fuel with air be in such proportions as ko provide from about ~.5 to about 30% by weight of ~lonia, other proportions ~ay be emp~oyed , ~ . outside of this prefel~.red range~ Similarly, a wide xange , .~ of compression~ are usable in combusting khe ~mmonia based . ,~
. compositions of t~e invention when mixed ~ith air, ~ ~hen the base fuel is an alcohol such a6 methanol, .: ~he compositions o~ the inventio~ are admixed with air fox . co~bustion (aftar volatilizat~on), The comprebsions usable ., ~ in combusting,the methanol ~asad compositions o~ the -. invention are within the nor~al and known compressions ~or ..

!', . . methanol used per se~ (Methanol responds well to highes~
,. ~ compression ratios~
r The petroleum distillates and organic amines may .
similarly be employed as fuels in conventional and known equipment ~or combusting such fuels withou~ major mod~fications~
., The following examples describe the ~anner and . ~ .
. j process of.'making and using the invention and se~ o~th ~he ,: . ~ , , , . ' ' ' ., . - , ~

_. _22 , (.11, ' ~ 3 best rnode contomplated by ~he inventor o~ carxying out ~,the lnvention ~ut ~re not to be construed as limiting.
., . . , E~:ample 1 .
'.,, . ' '' ' " .
A sui~able pressure xeaction vessel i9 charged wi~h 100 lbs, of liquid ~mmonia. ~o this charge there is added with fitirring 1 lb, of lithium borohydride, The ~esulting mixturë is stirred for abouk 15 ~inute~
and then transferred ~o a pressure colltainer where the . ' li~uid mixtur~ is maintained, The resulting fuel is useful to power turbine engines. Similarly, repeating the above procedure but replacing the li~hium ,borohydride ~ as employed t]lerein with an equal proportion of any other sf~, . hydrogen carrier compound suitable for compounding with a~monia as described pxeviously, a composition of the i ~nvention is obtained.
~.~ ' ' , ' "
Example 2 A suitable reaction vessel is ~larged ~ith 100 lbs.
of methanol. To thi~ charge there is added with mixing , , 3 lbs. of uns~mmetrical dimethylhydrazina, The resulting mixture ;s a fuel which may be used in in~exnal co~bustion engin . S milarly, repeating t~le above proce~ure bul~

. -23-'~''x' . ' "
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~,' . ' .
.: -- . . . . . _ ~ . - ~--,. .-~
, ~ ~ . .
: ~ .

. ~,11 ~ ' , .

replacing ~h~ UD~I as u~ed thcrein with any other hydrogen carxier previously desc~ibed a~ suit~le for admixture wi~h an alcohol, a composition of ~he ~nvention i~ obtai.ned~

E~nple 3 .;

A suitable ~es~el i9 charged with 100 lbs. o kerosene.
To this charge there is addcd with stirring 5 lbs. o -hydrazine base. Tlle resulting fuel may be used i~ a kerosene burning heatin~ plant. Similarly, following the above , proccdure but mixing in place of the i~ydrazin0 base any otller hyarogen carrier described above as sui~able for -mixture with a petrolcum distillate, compositions of the invention are obtained. ;

Example 4 A suitabIe vessel is chargea with 100 ~bs o~
dimethylamine. To the charge there i~ added with mixing -4 lbs. o~ uns~nmetricai dimethylhydrazine (UDMH) The resulting ~uel may be used to power heatin~ plan~s. Similarly, following the above procedure but replacing the UDMH as used thereln with any other hydrogen carrier aescribea a~ove as useful for mixture with an amine fuel, a composition of the in~ention is ob~ained, t'.. '` . ~' ' ,, ,'i :`.'` . ' ' ' ' '.
'.:` . ~ 2~ ~
. ~ .r .
' ' ~ ~, ,. . 1 ,,~"

~ r . ~ ;7 ~

., .

43163 .I
. , , .
;' . ' ' '~. .
.' .~ , , .'-The pressure container prepared ~n Example l .
above and contai~ g 99% by weight ç~mmonia w~ith 1%
. . by ~eight of lithium boxohyaride is attached to a S pr~s~ure reducing valve previously connected to an . .
.. air mixiny burner. The valve i 6 .open~d to permit ' the fuel composition to enter the burner head and . to be admixed with air ln the ratio o~ about 75 ~o .~ 25 parts of air to the fuel composlt;on~ The air .; ~uel compo6ition i~ ignited and foun~ to burn evenly with a briyht yellow flame. .

Example 6 .~ Following the general procedures outlined in Examples 1-4, inclusiYe, additional fuel compositions .
S of th nventicn mey be prep~red as follows~

- ~
v" ."' ,.' ',, " '. "' ",.

: . ~ ~ 25 -;~' ' .' ': ' ' ' , , " , '' ' ' ' ' ' ' ': ' ' ' ' ',,,,,,~,S,.. "
' ~., . . ' ' ' , , ' ' ' ' ' ' '`'. '`.

.
~ 63 ~ . . '~'.

, .~ . All o the abc:ve ~uel composi~ions may be ; '~ .,, used. a~ enexgy uels ~ rl conven~ional e.ngin~s, ~u~3ine~
~n~ , rg~ um~ vic ~ ' . ,' ~'~`;' '} . '- ' ' " '. '. ,' .~', '',,. ' ,;' ~' ~S~ '' ,' " '' I ' .~

,~ . _ z7 ,- . , ,i,'.,'' " . . ;
. ,. ,' "~.~,~'' , , i, . , '. ~ .' . . , . ~ , .

Claims (8)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A method of improving the combustion of ammonia, which comprises; mixing in said ammonia from 0.5 to 15 percent by weight of a hydrogen carrier; and combusting the resulting mixture; said hydrogen carrier being a compound selected from the group consisting of a boron hydride, a borohydride, a hydrazine and mixtures thereof, said compound having a molecular weight of from 8 to about 125 and a heat of formation of from about 10 kcal, to about 100 kcal. per mole; provided that the compound selected is non-reactive with the ammonia it is mixed in at ambient temp-eratures, does not lower the shelf life of the mixture, does not deteriorate below the ignition temperature of said mixture to release energy and at the point of ignition, releases energy and hydrogen, said mixture being non-hypergolic.

2. A composition, which comprises: from 85 to 99.5 percent by weight of ammonia; and from 0.5 to 15 percent by weight of hydrogen carrier, said hydrogen carrier being a compound selected from the group consisting of a boron hydride, a boro-hydride, a hydrazine and mixtures thereof, said compound having a molecular weight of from 8 to 125, a heat of formation of from about 10 kcal. to about 100 kcal. per mole; provided that the compound selected is non-reactive with the ammonia it is mixed in at ambient temperatures, does not lower the shelf life of the composition, does not deteriorate below the ignition temperature of said compostion to release energy and at the point of ignition, releases energy and hydrogen, said composition being nonhypergolic.

3. The composition of claim 2, wherein said ammonia is anhydrous.

4. The composition of claim 2 wherein said ammonia is dissolved in an organic solvent which is combustible.

5. A method as claimed in claim 1, in which said hydrogen carrier is an alkyl borane.

6. A composition as claimed in claim 2, in which the hydrogen carrier is an alkyl borane.

7. The composition of claim 6, wherein said ammonia is anhydrous.

8. The composition of claim 6, wherein said ammonia is dissolved in an organic solvent which is combustible.