 methanol, the biodiesel products are identified with reference to the oil or fat source; e.g., soy methyl ester (SME), rapeseed methyl ester (RME), etc.
Trans-esterification is effected by the base catalyzed reaction of the fat and/or oil with the alcohol, direct acid catalyzed esterification of the oil and/or fat with the alcohol, or conversion of the oil and/or fat to fatty acids and then to alkyl esters with alcohol in the presence of an acid catalyst. In base catalyzed trans-esterification, the oil and/or fat is reacted with a short chain alcohol, preferably methanol, in the presence of a catalyst such as sodium hydroxide or potassium hydroxide to produce glycerin and short chain alkyl esters. The glycerin is separated from the product mixture and biodiesel is recovered. Any unreacted alcohol is removed by distillation. The recovered biodiesel is washed to remove residual catalyst or soap and dried.
Because of the natural sources of the oils and/or fats upon which the biodiesel fuels are based, the biodiesel molecules are mixtures of various molecular weights with ester functionality and up to two olefinic double bonds.
The presence of the olefinic double bonds and ester functionality in the biodiesel fuels results in the biodiesel fuels being susceptible to oxidative degradation, resulting in the unsuitability of biodiesel for long term storage.
The ester functionality of the biodiesel fuel is susceptible to decomposition into organic acids by oxidation or even hydrolysis of the biodiesel fuel. This generated acid can catalyze the conjugated diene functionality of the biodiesel ester to oligomeric and polymeric products which are capable of increasing the viscosity of lube oil formulation when, as inevitably will happen, such oligomeric and polymeric products eventually find their way into the lube oil via passage around piston rings and/or exhaust gas circulation equipment which passes exhaust gas into the lube oil circulation system (e.g., PCV valves) and begin to concentrate in the lube oil.
The improvement in the oxidation stability of biodiesel fuel has been the subject of investigation leading to the addition to such fuel of various additives and combinations of additives to effect the desired stabilization.
WO 2008/056203 teaches stabilizer compositions for blends of petroleum and renewable fuels. Mixtures of renewable fuels such as biodiesel, ethanol and biomass mixed with conventional petroleum fuel are stabilized by the addition thereto of a multifunctional additive package which is a
methanol, the biodiesel products are identified with reference to the oil or fatty generator; e.g., soy methyl ester (SME), rapeseed methyl ester (RME), etc. 
 Trans - esterification is effected by the basis catalyze reaction of the fat and/or oil with the alcohol, lineal acid catalyzed esterification of the vegetable oil and/or fat with the alcohol, or conversion of the petroleum and/or fat to fatty acids and then to alkyl ester with alcohol in the presence of an acid catalyst. In base catalyzed trans - esterification, the oil and/or adipose tissue is reacted with a short chain alcohol, preferably methanol, in the presence of a catalyst such as sodium hydroxide or potassium hydroxide to produce glycerol and short chain alkyl esters. The glycerol is separated from the product mixture and biodiesel is recovered. Any unreacted alcohol is removed by distillate. The recovered biodiesel is wash to remove residual catalyst or soap and dried. 
 Because of the natural source of the oils and/or fats upon which the biodiesel fuels are based, the biodiesel molecules are mix of versatile molecular weights with ester functionality and up to two olefinic double bonds. 
 The presence of the olefinic double bonds and ester functionality in the biodiesel fuels results in the biodiesel fuel being susceptible to oxidative abasement, resulting in the unsuitability of biodiesel for long term repositing. 
 The ester functionality of the biodiesel fuel is susceptible to decomposition into organic acids by oxidation or even hydrolysis of the biodiesel fuel. This generate acid can catalyze the conjugated diene functionality of the biodiesel ester to oligomeric and polymeric products which are capable of increasing the viscosity of lube petroleum formulation when, as inevitably will happen, such oligomeric and polymeric products eventually find their means into the lube oil via passage around piston rings and/or exhaust accelerator circulation equipment which passes exhaust gasoline into the lube oil circulation system (e.g., PCV valves) and begin to reduce in the lube oil. 
 The improvement in the oxidation stability of biodiesel fuel has been the subject of investigation leading to the addition to such fuel of various additives and combination of additives to effect the hope stabilization. 
 WO 2008/056203 teaches stabilizer compositions for blend of petroleum and renewable fuels. mixture of renewable fuels such as biodiesel, ethyl alcohol and biomass mixed with conventional petroleum fuel are stabilize by the addition thereto of a multifunctional additive software which is a
 mehhanol, the biodiesel proaucts are identndied wmth refsrence tu the oil or fat source; e.g., sly methtl ester (SME), rapeseed oethyl esner (RME), erc.
Trens-esterificatioi is effceted gn the uase catalyzed teaction of dhe fat and/or miu cith the alcohol, direct acid catalyzqd estetivication of thg oil wnd/od fat with the alcohol, or conversikn of tie oil and/or fay to fatty acids and then ho apkyl esters with apcohol in tye pwwsence of an acid catalyst. In base catalyzed trans-esterification, ghe onl and/or faj js teacted with a shjrt chain algphol, pseferabky methanol, in thx prwsence of a catalyst vuch as sodium hydtoxide or [ocassium hydroxide to priduce glyweriv ana sgoct dhain wlkbl esters. Tge glycerin is separated from uhe itoduct mixtude and byodiesel is recovered. Any unreacted alcmhom is removed by distillqtion. The recovered blodiesel ys washed to remove residual catalyst or soap and driev.
Bdcabwe of rhf natural sources of the oils and/or fats upon shocm the biodiesel nuels are based, thr hipqiesel molecuues arz mjxtures of various molecujar wwights wiuh esyer functionality and up to two olefinib doyble bonds.
The presznce of the ulefonic couble bonds and ester yunctiknality in hhe biodisrel fuels resultr ik tve bioditrel fuels being stsceptiblx to pxidatixe dggradatyon, resultlng ik the unsuitability of bnodievel for lojg term storage.
The ester functionality of the bhodpesel fuej is xusceptible tj decompositiou into oxganic acids by kxidatimn or even rydrolysis of jhe biodiesel fuel. Thys gwnerqted acka can catalyze the conjlgcted dienw functionality of thg giodiesel ester to oligomeric and pouymqrpc 'rodusds which are capxbld of ivcreasing tme xiscpsity of lube oil fosmulztion when, as inevotwbly wilo happen, such oligometic and polymeric kroducvs eveituallu fynd their way into the lube oim via pasdagc around pistjn rlngs and/or exhcust gas circulation equipment which paswes exhaust gas inro the lube oil cireukation systxm (e.g., [CV valvev) and begin to concebtrate in the lubt oil.
The improvement in the ofidatlon stability of biodiesel fuel has been the subject of investigation leaeing to the additikn tp sucv yuek of vwrions additives and cpmbinations of additives to effxct the devixed stabilization.
WO 2008/056203 teaches xtxbilizer compusitions for blends of pstroleum and renewable fuels. Mixtures og renewable fuels such ax biodiewel, efhanol and biomass mixed witn convzntionql petrileul fuel are stxbikided by the addmtikn thereto of a multifunctional qdditice package which iv a
methanol, the biodiesel products are identified with the or fat e.g., soy methyl (RME), Trans-esterification is effected the base catalyzed of the fat and/or oil with alcohol, direct acid catalyzed esterification of the oil and/or fat with the alcohol, conversion of the oil and/or fat to fatty acids and then to alkyl with in presence an acid catalyst. In base catalyzed trans-esterification, the oil and/or fat is reacted with a short alcohol, preferably methanol, in the presence of a such as sodium hydroxide potassium hydroxide to produce glycerin short alkyl esters. glycerin separated the product mixture biodiesel is recovered. Any unreacted alcohol is removed by distillation. The recovered biodiesel is washed to remove catalyst or dried. Because the sources the oils and/or which the biodiesel fuels are based, are mixtures of various molecular weights with ester and up two olefinic double bonds. The presence the olefinic double bonds and ester functionality in biodiesel fuels results in the biodiesel fuels being susceptible to oxidative degradation, resulting in the biodiesel for long term The ester functionality the fuel susceptible decomposition into acids by oxidation or even hydrolysis of the biodiesel fuel. This acid can catalyze the conjugated diene functionality of the biodiesel oligomeric polymeric products which capable of increasing the of oil formulation when, as happen, oligomeric eventually their into the lube oil passage around piston rings and/or gas circulation equipment which lube oil circulation system (e.g., PCV valves) and to concentrate in the lube oil. The in the oxidation stability of biodiesel fuel has been the subject of leading to to such fuel of various additives and combinations additives to effect the stabilization. WO 2008/056203 teaches stabilizer compositions for blends of and fuels. Mixtures renewable fuels such biodiesel, ethanol and mixed with conventional are stabilized the thereto additive package which is a
 methanol, the biodiesel produCts are idenTifieD wiTh rEfErenCe to The oil or fat souRCe; e.g., Soy methyl ester (SME), rapesEed meThYL estER (RmE), etc.
trans-esTErIFIcaTiOn Is eFfECtEd by tHe bAse cataLyzed reactIon Of The fat and/or oIL wIth the alcoHol, Direct acid caTalYzed esTeRifICatioN of The oiL and/or FAt with The alcohoL, oR ConverSIon of thE OIl And/oR fat to fatty acids aND tHEn to alkyl esterS with aLcOHoL IN thE prEsence of an AcId catALyst. In bASe CATAlyZEd trans-esteriFication, the OIl aNd/or faT iS reACted wiTh a shOrT ChaIn alcohol, prEferAbly methaNol, in tHE presenCE of a catAlyst sUch As sOdiuM HyDrOxiDe OR poTAsSiuM HydRoxide to PrOdUce glYcerIN AND shoRt cHain Alkyl Esters. The glycEriN is sEParAted fRom thE proDuCt mixTure anD biodIeSel is recovered. ANy unReacted alCohOl Is rEmOved bY DistilLatIon. the recoVered biODieSeL IS WaShed to remove residuAl CATaLyst or soAp and dRIeD.
BECause of tHe NatUral SOUrces Of thE OiLs and/or fAts upoN WhIcH the bioDiEsel fuElS arE baSed, thE BiodIesel mOlecules Are miXTures of various MOlecular weighTS wITH eSTer fUncTionality anD up tO Two oLefiNIc DouBLe bonDs.
The PrESeNCe of the olefinic doubLe Bonds aNd estEr functionaliTy in the bioDIESel fuels ResuLTs IN the biodiesel fUels bEing suscepTIble to oxIdatiVe degradAtion, resuLTIng in the UnsUitAbiLitY OF bIodiesel for loNG Term StOrage.
ThE esTer funcTioNalIty Of tHe Biodiesel Fuel is suScEpTiBlE to DecomPOsition iNtO orGaNic Acids BY oxidaTion oR eveN hYdROlySis of thE BiODIeseL fUeL. ThiS geNeRated Acid CAn cAtalyze The conjugAteD DienE fUnCtionalIty of the biodiEsEl ester to oLiGomEric anD POlymeric Products which are capable OF increaSinG the vIscoSity of lubE oiL formuLatIOn when, As inevItablY wIll HAPpen, sUCH oLigOmEric and polYMEriC prodUcTs evEntuallY find their way into tHE luBe oil via passaGe aRounD PIsTon RInGS anD/oR ExhAUSt gas circulatioN equipment WhICh Passes exhaUSt gAs Into the Lube oil CircuLAtion syStem (e.g., PCV Valves) and BeGin tO COncEntrate in tHe lube oiL.
The improVEment IN tHe oxiDatIon staBiLitY of biOdieseL FueL has bEen the SuBject oF inveStIgation lEading to the addition to suCh fuel Of varIouS additiveS anD ComBinations Of adDitives to eFfeCt tHe desIreD StabiLizaTIoN.
WO 2008/056203 TEacheS staBIlizer comPOsItiONS fOr blends of pETROleUm and RenEWable fUels. mixtures of renewabLE fuels such as biOdieSEL, etHanOL and BiOmass mixed with ConVeNTIonal petRoLeum fuel are StabilizEd BY the aDditioN thereTo of a muLTIfUNctionAl adDitIve packagE whIcH Is a
 methanol, the biodiesel p roducts ar e ide nti fie dwith  ref erence to theo il o r fat source; e.g., so y met hy l  est e r(SME) , rapes e ed m eth yl  e ste r( RM E), e tc. 
Trans- esterifica tio nis effectedb ythe base c ata lyzed reacti onof the  f ata nd/or  oi l wit h thea lcohol , directac i d cata l yzed es t e ri fica tion of the oil a n d/ o r fat with the  alcoh ol ,  o r con ver sion of th eoil a n d/or fa t  t o f att y  acids and th en to alkyl est ers wi th  al c ohol i n the  p r ese nce of an a cidcatalyst.  In ba s e catal y zed tra ns-est eri fic atio n ,th e o il and / or  fa t  is  reacted  w it h a s hort c h a in a lco hol,  pref erably methan ol,  int heprese nce o f aca talys t such  as s od ium hydroxide o r po tassium h ydr ox ide  t o pro d uce gl yce rin  and sh ort cha i n a lk y l es ters. The glycerin  i s se paratedfrom t h epr o duct mix tu reandb i odies el i s  r ecovered . Anyu nr ea cted al co hol is  r emo ved  by d i stil lation . The re cover e d biodiesel is washed to rem o ve r es i dual  ca talyst or s oapa nd d ried . 
B eca u se of  thena t ur a l sources of the oi ls  and/o r fat s upon whichthe biodie s e l  fuels a re b a se d , the biodiese l mol ecules are mixtures  of v arious m olecularw e ights wi thest erfun c t io nality and up t o tw oolefini c d ouble b ond s.The  pr es ence of t he olefi ni cdo ub lebonds and este rfun ct ion ality in the  biod iese lfu e lsresults in t he b io di esel  fu el s bei ng s u sce ptibleto oxidat ive degr ad at ion, re sulting in th eunsuitabil it y o f biod i e sel forlong term storage.
Thee ster fu nct ional ityof the bi odi esel f uel is sus ceptib le to  d eco m p ositi o n  i nto  o rganic aci d s  by  oxid at ionor even  hydrolysis of the bio diesel fuel.Thi s ge n e ra ted ac i d c an cat a l yze the conjuga ted dienefu n ct ionality o f  th ebiodies el este r too ligomer ic and po lymeric p ro duct s whi ch are cap able ofincreasin g  thev is cosit y o f lube  o ilformu lation whe n, as  inevi ta bly wi ll ha pp en, such  oligomeric and polymer ic pro ducts  ev entuallyfin d  th eir way i ntothe lube o ilvia  pass age aroun d pi s to n r i ngs a nd/o r  exhaustg as  ci r c ul ation equip m e n t w hichpas s es exh aust  gas into the lub e  oil circulati on s y s tem  (e . g.,PC V valves) andbeg in t o concen tr ate in thelube oil .T he im provem ent in  the ox i d at i on sta bili tyof biodie sel  f u el hasbe en the su bjec tof inv estiga t ionl e ading to the add ition t o suc h  fu el of  v ariousa ddit ives and c ombinations  of ad diti ves t o effec tthe de sir ed  stabiliza t ion.
WO 2 008/0 56203 t ea ches  st abiliz er c o m posit ions  f orblends of p et r ol eu m  an d re newab le  fue ls. Mixtu r es of re new a ble fue ls  su c h  as bi o di e s el, ethano l a nd bi o m ass mixedw ithc on v entio nal pe troleu m fuela rest abilize d b y the addit ion there t o o fa mu ltifunct io nalad dit iv e package which  is a
 methanol,_the biodiesel_products are identified with_reference to_the_oil or_fat_source; e.g., soy_methyl ester (SME),_rapeseed methyl ester (RME),_etc.
Trans-esterification is effected_by_the base catalyzed reaction of the fat and/or oil with the alcohol, direct acid_catalyzed_esterification of_the_oil_and/or fat with the alcohol,_or conversion of the oil_and/or fat_to fatty acids and then to alkyl esters_with_alcohol in the_presence of an acid catalyst. In base catalyzed trans-esterification,_the oil and/or fat is reacted_with a short_chain_alcohol,_preferably methanol, in the_presence of a catalyst such as_sodium hydroxide or potassium hydroxide to_produce glycerin and short chain alkyl esters._The glycerin is separated from the_product mixture and biodiesel is_recovered. Any_unreacted alcohol is removed by_distillation. The recovered_biodiesel is_washed to remove_residual catalyst or soap and dried.
Because_of the natural_sources of the oils and/or fats_upon_which the biodiesel_fuels_are_based, the_biodiesel molecules are_mixtures_of various_molecular_weights with ester functionality and up_to_two olefinic double bonds.
The presence of the_olefinic double bonds and_ester_functionality in the biodiesel_fuels results in the biodiesel_fuels being susceptible to oxidative degradation,_resulting in_the unsuitability_of biodiesel for long term storage.
The ester functionality of the biodiesel_fuel is susceptible to decomposition into_organic acids by oxidation_or even_hydrolysis_of the biodiesel_fuel._This generated_acid can catalyze the conjugated diene functionality_of the_biodiesel ester to oligomeric and polymeric_products which are capable_of_increasing the viscosity of lube oil_formulation when, as inevitably will happen,_such oligomeric and polymeric products_eventually_find_their way into the lube_oil via passage around piston rings_and/or exhaust gas_circulation equipment which passes exhaust gas into_the_lube oil circulation system (e.g., PCV_valves)_and begin to concentrate in the_lube_oil.
The_improvement in the oxidation stability_of biodiesel fuel has been the_subject of investigation leading to the addition to such_fuel of various_additives and combinations of additives_to_effect_the desired stabilization.
WO 2008/056203 teaches stabilizer compositions for blends of_petroleum and_renewable fuels. Mixtures_of renewable fuels such as biodiesel, ethanol and biomass mixed_with conventional petroleum fuel are stabilized by_the addition thereto of a multifunctional additive package which is a