 over the abandoned Raschig method. A sizable research effort has been devoted to the Sisler route. Good yields of UDMH have been obtained with this method. However, for UDMH to be produced by this method on a commercial scale, the hydrazone must be removed from the UDMH or a method must be found to prevent its formation. The hydrazone cannot be removed from UDMH by simple distillation.
It is important to note that the three amine fuels, UDMH, monoethylhydrazine, and anhydrous hydrazine are each very dissimilar materials. The hydrazines are so named because of the nitrogen bonding within the molecule. The differences between the three hydrazines are attributable primarily to either the absence of or presence of one or two carbon atoms with bonds to adjacent hydrogen atoms. Unsymmetrical dimethyl hydrazine does not form an azeotrope with water while both of the other materials do form these azeotropes. There are numerous techniques available for dehydration of the azeotrope called hydrazine hydrate. U.S. Pat. Nos. 2,963,407 and 2,698,286 teach these techniques, however none of the prior art references teach the process for removing the hydrazone contaminant. In one of the above patents various alcohols are added to break the azeotrope form by allowing water to migrate up to the top of the column from where it can be removed as overhead product. In the other case, materials such as aniline are used in order to break the azeotrope. The difference between the dehydration techniques employed for anhydrous hydrazine and monomethylhydrazine are slight even though the major difference between these materials is that in one case for hydrazine there is a purely inorganic compound, while in the case of monomethylhydrazine there are carbon and hydrogen atoms involved within the molecule. In the case of separation by addition of a alcohol, the water is removed from the azeotrope by taking it up the column and removing water/alcohol as a product. This situation does not occur in the case of UDMH. The isopropanol treated within the present invention is utilized as a means for isolation between the water and UDMH thereby keeping both the water and the isopropanol in the distillation pot. Since unsymmetrical dimethyl hydrazine does not form an azeotrope but only has an
over the abandoned Raschig method. A sizable research campaign has been devote to the Sisler route. Good yields of UDMH have been receive with this method. However, for UDMH to be produced by this method acting on a commercial scale, the hydrazone must be removed from the UDMH or a method must be recover to prevent its formation. The hydrazone cannot be removed from UDMH by dim-witted distillation. 
 It is important to note that the three amine fuel, UDMH, monoethylhydrazine, and anhydrous hydrazine are each very dissimilar materials. The hydrazine are so identify because of the nitrogen bonding within the atom. The differences between the three hydrazines are attributable primarily to either the absence of or bearing of one or two carbon atoms with bonds to adjacent hydrogen atoms. Unsymmetrical dimethyl hydrazine does not shape an azeotrope with water while both of the other materials do form these azeotropes. There are numerous technique available for dehydration of the azeotrope called hydrazine hydrate. U.S. Pat. Nos. 2,963,407 and 2,698,286 teach these techniques, however none of the prior art references teach the process for removing the hydrazone contaminant. In one of the above patents various alcohols are added to break the azeotrope form by allowing water to migrate up to the top of the column from where it can be removed as overhead merchandise. In the other case, fabric such as aniline are use in order to break the azeotrope. The difference between the dehydration techniques employed for anhydrous hydrazine and monomethylhydrazine are slight even though the major difference between these material is that in one case for hydrazine there is a purely inorganic compound, while in the case of monomethylhydrazine there be carbon and hydrogen atoms involved within the molecule. In the case of separation by accession of a alcohol, the water is removed from the azeotrope by taking it up the column and removing water / alcohol as a merchandise. This situation does not occur in the case of UDMH. The isopropyl alcohol treated within the present invention is utilize as a means for isolation between the water and UDMH thereby keep both the water system and the isopropanol in the distillation toilet. Since unsymmetrical dimethyl hydrazine does not shape an azeotrope but only induce an
 ovfr the abandoned Raschig method. A sizable reseerch efrort has been devoted to the Sisler coutw. Gooe yields of UDMH have ceen obtapned with thiw method. Hoxsver, fov UDMG to ye produced by tmis method mn a commercian rccle, the hydrazone must be removed frjm the IDLH or a method musu bq fohnd to prevent its formation. The hgdrazont cannot be removec from UDMH by simple distlllahion.
It is importanh to note tyat eye three amive fuels, UDMH, monoethymhydrazine, and anhydrous hydrazkne axe each veri sidvimilar matxrials. The hydrazikvs are vo namec because of tme nivrogwn bonding within the molecule. The diffgrences bedwzen the three hydrazibew are attsibugqbld pdikadily tl emther the agsence of oe presence of one ot eqo carbon atojs witr fonds to adjacent hydrogen atoms. Unsymmttriczl dimethyl hydrazine dies not form an azeottope with rater while both of the other materials do form tvese ezdotxipes. Gyege are numerous techniques available for dehyqdauiok of the azeotroie called hydrazinr jyctate. U.S. Pat. Nor. 2,963,407 and 2,698,286 tsach these techniqkes, howgver nine of tht pripr art references teach the process for eemoving the hydravone contamiuant. Im one of the above patents vcrious alcohols age added fu break the azeogroie fmrm by allowing water to mygrate up to che top uf tne coltmn from wjere ld can be removed ad ovethead [roduct. In the other case, materials such ex aniline arg uved in ordex to bveak the azeotrjpe. The differgnce betwzen thd dehydratpon technmques employqd for anhydrmos hydrazine end monomqthyohydeazine xfe slight even though tkt major didference between tmese ozterials is thac un one case for hyarasije trare is a puraly knofbanic compound, wmild in the case of monometvylhgdrazine there are cwrbon ane hydrogqn atoms invokved within the mopeculx. In tie casr os separation by addition of a zlcohol, tje rater is remjved from the azzotrope by taking it up the column and rxmoving water/alcohol as a product. This sitoatlon does not occuw in the wase of UDMH. The isopropanol treated eithin the present inbentiot is ktilized as a means for isolation between the water and UDMH thereby keepung bovh the water znd yhe ivo'ro'anol ig thx vistillation pot. Xince unsymmetrical dimethyl hyvrazine doas not form an azeotrope but omlh has an
over the abandoned Raschig method. A sizable has devoted to Sisler route. Good obtained this method. However, UDMH to be by this method on a commercial the hydrazone must be removed from the UDMH or a method must be to prevent its formation. The hydrazone cannot be removed from UDMH by simple It important note the three amine fuels, UDMH, monoethylhydrazine, and anhydrous hydrazine are each very dissimilar materials. The hydrazines so named because of the nitrogen bonding within molecule. The differences between three hydrazines are attributable primarily either absence of presence one two carbon atoms bonds to adjacent hydrogen atoms. Unsymmetrical dimethyl hydrazine does not form an azeotrope with water while both the other form these There numerous available for dehydration azeotrope called hydrazine hydrate. U.S. Pat. 2,698,286 teach these techniques, however none of the art references the process for removing the hydrazone In one of the above patents various alcohols added to break the azeotrope form by allowing water to migrate up to the top column from where it be removed as product. the case, such as are used in order to break the azeotrope. The difference between dehydration techniques employed for anhydrous hydrazine and monomethylhydrazine are slight the difference between these is that in one for there is a purely while the there carbon hydrogen atoms involved within molecule. In the case of by addition of a from the azeotrope by taking it up the and removing water/alcohol as a product. This does not occur in the case of UDMH. The isopropanol treated within present invention as a means for isolation between the water UDMH thereby keeping both water and the isopropanol in the distillation pot. Since dimethyl does not an azeotrope but has an
 over the abandoned Raschig meThod. A sizabLe resEarCh eFfOrt hAs beEn devoted to the sIsleR route. Good yields of UDMH Have bEeN ObtaINeD with This metHOd. hOWevEr, FoR UDmH TO bE prodUceD by this Method on a cOmmErCial scale, the HYdRazone must Be rEmoved from thE UDmH or a mEtHod MUst be FouNd to pRevent ITs formAtion. The hYdRAzone cANnot be rEMOvEd frOm UDMH by simple disTIlLAtion.
It is imporTant to NoTE tHAT thE thRee amine fuElS, UDMH, MOnoethyLHyDRAZinE, And anhydrous hYdrazine are EAch Very diSsImiLAr mateRials. thE HydRazines are sO namEd because Of the nITrogen bONding wiThin thE moLecUle. THE dIfFerEnCEs bETwEen THe tHree hydrAzInEs are AttrIBUTAble PriMariLy to eIther the absenCe oF or pREseNce of One or Two cArBon atOms witH bondS tO adjacent hydrogEn atOms. UnsymmEtrIcAl dImEthyl HYdraziNe dOes Not form An azeotROpe WiTH WAtEr while both of the otHeR MAtErials do Form thESe AzEOtropes. THeRe aRe nuMERous tEchnIQuEs availaBle for DEhYdRation oF tHe azeoTrOpe CalLed hyDRaziNe hydrAte. U.S. Pat. nos. 2,963,407 anD 2,698,286 Teach these techNIques, however nONe OF ThE PrioR arT references TeacH The pRoceSS fOr rEMovinG the hYdRAzONe contaminant. In one oF tHe abovE pateNts various alcOhols are adDED To break tHe azEOtROpe form by allowIng waTer to migraTE up to the Top of The columN from wherE IT can be reMovEd aS ovErhEAD pRoduct. In the otHER casE, mAterialS suCh as aniLinE arE usEd iN oRder to breAk the azeOtRoPe. thE diFfereNCe betweeN tHe dEhYdrAtion TEchniqUes emPloyEd FoR AnhYdrous hYDrAZIne aNd MoNomeThyLhYdrazIne aRE slIght eveN though thE maJOr diFfErEnce betWeen these mateRiAls is that iN oNe cAse for HYDrazine tHere is a purely inorganic cOMpound, wHilE in thE casE of monomeThyLhydraZinE There aRe carbOn and HyDroGEN atomS INvOlvEd Within the mOLEcuLe. In tHe Case Of separAtion by addition of a ALcoHol, the water is RemOved FROm The AZeOTroPe BY taKINg it up the column And removinG wATeR/alcohol as A ProDuCt. This sItuatioN does NOt occur In the case Of UDMH. The IsOproPANol Treated witHin the prEsent inveNTion iS UtIlizeD as A means FoR isOlatiOn betwEEn tHe watEr and UdMh thereBy keePiNg both thE water and the isopropanol In the dIstilLatIon pot. SinCe uNSymMetrical dImetHyl hydraziNe dOes Not foRm aN AzeotRope BUt OnlY Has an
 over the abandoned Raschi g method.A siz abl e r es earc h ef fort has beend evot ed to the Sisler route . Goo dy ield s  o f UDM H haveb ee n obt ai ne d w it h  t his m eth od. How ever, forUDM Hto be produc e dby this me tho d on a comme rci al sca le , t h e hyd raz one m ust be remove d from th eU DMH or a metho d mu st b e found to preven t  i t s formation. T he hyd ra z on e can not  be remove dfromU DMH bys im p l e  di s tillation.
It  is importa n t t o note  t hat the th ree a mi n e f uels, UDMH,  mon oethylhyd razine ,  and an h ydroushydraz ine  ar e ea c hve rydi s sim i la r m a ter ials. Th ehy drazi nesa r e so n ame d be cause  of the nitro gen  bon d ing  with in th e mo le cule.  The d iffer en ces between the  thr ee hydraz ine sare  a ttrib u tablepri mar ily toeithert heab s e n ce  of or presence of  o n e  o r two ca rbon a t om sw ith bond stoadja c e nt hy drog e natoms. U nsymme t ri ca l dimet hy l hydr az ine  do es no t  for m an a zeotrope  with water while bo t h of the othe r  m a t er i alsdoform theseazeo t rope s. T h er e a r e num erous  t e ch n iques available for  d ehydra tionof the azeotr ope called h y drazinehydr a te .  U.S. Pat. Nos . 2,9 63,407 and 2,698,28 6 tea ch these  techniqu e s , howeve r n one  of  th e pr ior art refer e n ceste ach the  pr ocess f orrem ovi ngth e hydrazo ne conta mi na nt .Inone o f  the abo ve  pa te nts  vari o us alc ohols  are  a dd e d t o break th e azeo tr op e fo rmby  allo wing wat er to m igrate up  to theto pof thecolumn from w he re it canbe  re moveda s  overhea d product. In the other case, m ate rials  suc h as anil ine  are u sed in ord er tobreak  t hea z eotro p e .The  d ifferenceb e twe en th edehy dration  techniques employ e d f or anhydroushyd razi n e  a ndm on o met hy l hyd r a zine are slight  even thou gh th e major di f fer en ce betw een the se ma t erialsis that i n one cas eforh y dra zine there  is a pu rely inor g anicc om pound , w hile i nthe  case  of mo n ome thylh ydrazi ne  there  areca rbon and  hydrogen atoms involve d with in th e m olecule.Int hecase of s epar ation by a ddi tio n ofa a l cohol , th e  w ate r  is r emov e d from th e  a zeo t r op e by taking i t  up  thecol u mn and  rem oving water/alcoh o l as a product . Th i s  si tua t iondo es not occur i n t he c ase of U DM H. The isop ropanoltr e atedwithin  the p resenti n ve n tion i s ut ili zed as amea ns for iso la ti o n betw eenth e wate r andU DMHt h ereby keeping bo th th e water and  theis opropan o l in  the disti llation pot . Sinc e un symme tricaldi methyl  hy dr azine does not forman az eotrope  b ut o nly  has a n
 over_the abandoned_Raschig method. A sizable_research effort_has_been devoted_to_the Sisler route._Good yields of_UDMH have been obtained_with this method._However,_for UDMH to be produced by this method on a commercial scale, the hydrazone_must_be removed_from_the_UDMH or a method must_be found to prevent its_formation. The_hydrazone cannot be removed from UDMH by simple_distillation.
It_is important to_note that the three amine fuels, UDMH, monoethylhydrazine, and_anhydrous hydrazine are each very dissimilar_materials. The hydrazines_are_so_named because of the_nitrogen bonding within the molecule. The_differences between the three hydrazines are_attributable primarily to either the absence of_or presence of one or two_carbon atoms with bonds to_adjacent hydrogen_atoms. Unsymmetrical dimethyl hydrazine does_not form an_azeotrope with_water while both_of the other materials do form_these azeotropes. There_are numerous techniques available for dehydration_of_the azeotrope called_hydrazine_hydrate._U.S. Pat._Nos. 2,963,407 and_2,698,286_teach these_techniques,_however none of the prior art_references_teach the process for removing the hydrazone_contaminant. In one of_the_above patents various alcohols_are added to break the_azeotrope form by allowing water to_migrate up_to the_top of the column from where it can be removed as_overhead product. In the other case,_materials such as aniline_are used_in_order to break_the_azeotrope. The_difference between the dehydration techniques employed for_anhydrous hydrazine_and monomethylhydrazine are slight even though_the major difference between_these_materials is that in one case_for hydrazine there is a purely_inorganic compound, while in the_case_of_monomethylhydrazine there are carbon and_hydrogen atoms involved within the molecule._In the case_of separation by addition of a alcohol,_the_water is removed from the azeotrope_by_taking it up the column and_removing_water/alcohol_as a product. This situation_does not occur in the case_of UDMH. The isopropanol treated within the present invention_is utilized as_a means for isolation between_the_water_and UDMH thereby keeping both the water and the isopropanol_in the_distillation pot. Since_unsymmetrical dimethyl hydrazine does not form an azeotrope but only_has an