SE184234C1

SE184234C1 -

Info

Publication number: SE184234C1
Authority: SE
Publication date: 1963-01-01

Description

Uppfinnare: W R Keeler, D R Douslin och C H Deal, jr Uppfinningen avser en forbattring av det satt som utgor foremal f8r patent 175 715 och avser att framstalla vatesuperoxid genom partiell oxidation av sekundara alkoholer, varvid vatesuperoxiden utvinnes ur den densamma innehfillande oxidationsprodukten. Inventors: W. R. Keeler, Dr. R. Douslin and C. H. Deal, Jr. The invention relates to an improvement in the process of patent 175 715 and to the production of hydrogen superoxide by partial oxidation of secondary alcohols, the hydrogen superoxide being recovered from the same containing oxidizing product.

Enligt huvudpatentet framstalles salunda vatesuperoxid pa ett f5r teknisk drift lampligt satt genom att en sekundar alkohol, foretradesvis isopropylalkohol, i flytande f as oxicleras med en molekylart syre innehallande gas, foretradesvis i narvaro av en initiator for peroxidreaktionen, namligen en ringa mangd vateperoxid eller flagon annan peroxid, och vid forhojd temperatur, namligen vid fran omkring 70° C till 160° C, foretradesvis fran 90° C till 10 G, samtidigt som man noga tillser att den vatskeformiga reaktionsblandningen Mlles ur beroring med amnen, som astadkomma sonderdelning av peroxider, samt att vatesuperoxid utvinnes ur reaktionsblandningen. Da oxidationen av den sekundara alkoholen fortskrider, Midas vatesuperoxid, som ansamlas i den vatskeformiga reaktionsprodukten till dess att koncentrationer av upp till 10 % eller darutover anda upp till gransen for riskfri drift uppnatts. Den erMina vatskeformiga oxidationsprodukten har befunnits utom vatesuperoxid innehfilla en darmed ungefar ekvivalent mangd av sasom biprodukt uppstaende keton, vidare den oforbrukade delen av den sasom utgangsmaterial anvanda sekundara alkoholen samt sma mangder av vattenlosliga organiska produkter harrorande fran bireaktioner. Om aldehyder aro narvarande, fir mangden av dessa endast obetydlig och forsumbar jamfort med mangden av vatesuperoxid och keton. En typisk sammansattning av oxidationsprodukten av isopropylalkohol vid anvandande av ett av de namnda forfarandena ar foljande: Komponent Viktsproeent (torr) Isopropylalkohol 67 Aceton 22 Aktivt syre* sasom 11202 9 Aldehyder sasom acetaldehyd <0,0 Andra organiska fororeningar sasom C 0,01-0, * Peroxi (-0-0—) syre. According to the main patent, hydrogen peroxide is thus conveniently prepared for a technical operation by oxidizing one second of alcohol, preferably isopropyl alcohol, in liquid phase with a molecular oxygen-containing gas, preferably in the presence of an initiator of the peroxide reaction, namely a small amount of other peroxide. peroxide, and at elevated temperature, namely from about 70 ° C to 160 ° C, preferably from 90 ° C to 10 G, while carefully ensuring that the liquid reaction mixture is removed from contact with the substances which cause peroxides to be probed, and that hydrogen superoxide is recovered from the reaction mixture. As the oxidation of the secondary alcohol progresses, Mida's hydrogen superoxide, which accumulates in the liquid reaction product until concentrations of up to 10% or more exceeds the limit for safe operation. My liquid oxidation product has been found in addition to hydrogen superoxide to contain an approximately equivalent amount of ketone arising as a by-product, as well as the unused portion of the secondary alcohol used as a starting material and small amounts of water-soluble organic products resulting from side reactions. If aldehydes are present, the amount of these is only insignificant and negligible compared to the amount of hydrogen peroxide and ketone. A typical composition of the oxidation product of isopropyl alcohol using one of the above procedures is as follows: Component Weight percentage (dry) Isopropyl alcohol 67 Acetone 22 Active oxygen * such as 11202 9 Aldehydes such as acetaldehyde <0.0 Other organic impurities such as C 0.01-0 , * Peroxi (-0-0—) acid.

Foreliggande uppfinning baserar sig pa iakttagelsen, att den raa oxidationsprodukt, som erhalles genom partiell oxidation av sekundara alkoholer, utom vatesuperoxid kan innehalla aktivt syre (peroxi-syre), foreliggande I annan form an som vatesuperoxid, eventuellt i form av organiska peroxider. Totala mangden air aktivt syre foreliggande i form av dylikt bundet peroxi-syre (sasom det icke i form air vatesuperoxid foreliggande aktiva syret kan benamnas) kan variera mom betydande granser beroende pa de ursprungligen i reaktionsblandningen forhandenvarande komponenterna och den sa.som utgangsmaterial anvanda sekundara alkoholen liksom aven pa de speciella betingelserna vid oxidationen av den sekundara alkoholen. Mangden av bundet peroxi-syre kan variera frail nagra fa pro centav totala mangden aktivt syre upp till 50 % darav. The present invention is based on the observation that the crude oxidation product obtained by partial oxidation of secondary alcohols, except hydrogen peroxide, may contain active oxygen (peroxyacid), present in another form than hydrogen peroxide, optionally in the form of organic peroxides. The total amount of active oxygen present in the form of such bound peroxyacid (as the active oxygen not present in hydrogen peroxide can be termed) can vary considerably depending on the components originally present in the reaction mixture and the secondary alcohol used as starting material. as well as on the special conditions of the oxidation of the secondary alcohol. The amount of bound peroxyacid may vary from a few percent of the total amount of active oxygen up to 50% thereof.

Det bundna peroxi-syret har befunnits foreligga i en form eller typ ay kemisk forening, som i huvudsak icke ingar flagon reaktion med kaleiumhydroxid. The bound peroxyacid has been found to be in a form or type of chemical compound which does not substantially react with potassium hydroxide.

Den kemiska form, i vilken del bundna peroxi-syret foreligger, har icke helt klarlagts. Det har angivits, att organiska peroxider, sarskill polymera organiska peroxider, forefinnas i de raa oxidationsprodukterna. Det är mojligt, att keton-peroxider och sarskilt polymera 2— — ketonperoxider likaledes dro narvarande. Alclehyder, om- sadana overhuvudtaget bildas, och peroxi-foreningar av dessa, foreligga i mangder, som joke ph langt nar motsvara de mangder av bundet peroxi-syre, vilka kunna forekomma. The chemical form in which some of the bound peroxyacid is present has not been fully elucidated. It has been stated that organic peroxides, especially polymeric organic peroxides, are present in the crude oxidation products. It is possible that ketone peroxides and especially polymeric 2-ketone peroxides are also present. Alclehydes, whether formed at all, and peroxy compounds thereof, are present in amounts which, as a joke, are far from corresponding to the amounts of bound peroxy-oxygen which may occur.

Narvaron av bundet peroxi-syre liar befunnits leda till vissa svarigheter. Dessa aro: I) Flyktighetskarakteristiken hos det bundna peroxi-syret ãr sadan, att, cla oforbukad sekundar alkohol och sasom biprodukt erhallen keton avdestilleras fran den ran oxidetionsprodukten, det bundna peroxi-syret tenderar att avgá tillsammans darmed. Detta peroxi-syre tenderar aven ehuru det forflyktigas endast i sma mangd.er, att inaktivera eller forgifta hydreringskatalysatorer. Da man onskar att av keton-biprodukten genom hydrering aterbilda den shsom utgdngsmaterial anvanda sekundara alkoholen liar man darfor varit tvungen att rena, t. ex. fraktionera, den keton-biprodukten innehallande destillatfraktionen fore hydreringen for att effektivt kunna genomfora denna sistnamnda. The presence of bound peroxy-oxygen has been found to lead to certain similarities. These are: I) The volatility characteristic of the bound peroxyacid is such that, as unbound seconds of alcohol and as a by-product obtained ketone is distilled off from the crude oxidation product, the bound peroxyacid tends to escape therewith. This peroxyacid, although volatilized only in small amounts, tends to inactivate or poison hydrogenation catalysts. When it is desired to recover from the ketone by-product by hydrogenation the secondary alcohol used as starting material, it is therefore necessary to purify, e.g. fractionation, the ketone by-product containing the distillate fraction before the hydrogenation in order to be able to carry out the latter efficiently.

Mindre flyktigt bundet peroxi-syre, som hittills kvarblivit i den sasom bottenprodukt yid destillationen erhallna vattenlosningen av vatesuperoxid, reagerar icke med kalk under de betingelser, som aro lampliga for utvinning av vatesuperoxid genom utfallning sâsom kalciumperoxid. Da den i destillationsaterstoden forefintliga vatesuperoxiden omvandlas till kalciumperoxid genom reaktion med kalciumhydroxid, uppstar darfor en betydande forlust av aktivt syre. Less volatilely bound peroxyacid, which has hitherto remained in the aqueous solution of hydrogen peroxide obtained as the bottom product by distillation, does not react with lime under the conditions suitable for the recovery of hydrogen peroxide by precipitation such as calcium peroxide. As the hydrogen peroxide present in the distillation residue is converted to calcium peroxide by reaction with calcium hydroxide, a significant loss of active oxygen therefore occurs.

Det mindre flyktiga bundna peroxisyret innehdller kol. Narvaron darav komplicerar efterfoljande rening och/eller koncentrering av vatesuperoxiden genom forangning. Detta beror dels ph den store risken for explosioner eller andra haftiga reaktioner mellan vatesuperoxid i relativ koncentrerad form och organiska amnen, dels pa att flyktighetskarakteristiken hos det mindre flyktiga bundna peroxi-syret gOr det myeket svart att soparera detsamma fran vattenlosningen av vatesuperoxid. The less volatile bound peroxyacid contains carbon. The narvaron thereof complicates subsequent purification and / or concentration of the hydrogen superoxide by evaporation. This is partly due to the high risk of explosions or other violent reactions between hydrogen peroxide in relatively concentrated form and organic substances, and partly because the volatility characteristics of the less volatile bound peroxyacid make it very difficult to separate it from the aqueous solution of hydrogen peroxide.

Det bundna peroxi-syret innebar i den man det innefattar ketonperoxider och polymera ketonperoxider en fOrlust av keton, som annars skulle kunna omvandlas till sekundar alkohol och anvandas ph nytt i processen. The bound peroxyacid in the man it includes ketone peroxides and polymeric ketone peroxides meant a loss of ketone, which could otherwise be converted to secondary alcohol and used ph again in the process.

Det her nu befunnits, att det bundna peroxi-syret i rhprodukten frail partiell oxidation av lagre sekundara alkoholer innehallande shdant syre och vatesuperoxid kan selektivt sOnderdelas till vatesuperoxid utan namnvard sonderdelning av vatesuperoxiden. Genom att utfora en sadan selektiv son:derdelning av det bundna peroxi-syret i enlighet med forfarandet enligt foreliggande uppfinning kan man framstalla en betydande mangd vatesuperoxid, som adderar sig till den i den raa oxidationsprodukten ursprungligen forhandenva rande vatesuperoxiden. Oforbrukad sekundar alkohol och keton kunna separeras frail den rda oxidationsprodukten samtidigt med den selektiva sOnderdelningen av det bundna peroxi-syret, varvid man erhaller en vattenlosning innehallande vatesuperoxid i sterre utbyte raknat ph den totala mangd aktivt syre, som ursprungligen forefinnes i den ran oxidationsprodukten. Vidare atervinner man betydligt mera av biprodukten keton, och efterfoljande steg avseende utvinning, rening och koncentrering av vatesuperoxiden underlattas i hog grad. It has now been found that the bound peroxy oxygen in the raw product from the partial oxidation of lower secondary alcohols containing shdant oxygen and hydrogen peroxide can be selectively decomposed into hydrogen superoxide without nominal separation of the hydrogen peroxide. By performing such a selective decomposition of the bound peroxyacid in accordance with the process of the present invention, a significant amount of hydrogen peroxide can be produced which adds to the hydrogen peroxide originally present in the crude oxidation product. Unused seconds of alcohol and ketone can be separated from the red oxidation product at the same time as the selective decomposition of the bound peroxyacid to give an aqueous solution containing hydrogen peroxide in a higher yield of the total amount of active oxygen originally present in the raw oxidation product. Furthermore, significantly more of the by-product ketone is recovered, and subsequent steps regarding recovery, purification and concentration of the hydrogen peroxide are greatly facilitated.

Forfarandet enligt uppfinnigen utfores genom att underkasta den raa oxidationsprodukten en reglerad varmebehandling och en rektifikation i en fraktioneringskolonn under kontrollerade driftsbetingelser och genomforingshastighet genom kolonnen. Enligt en foredragen utforingsform utforas varmebehandlingen och rektifikationen samtidigt i en rektifikationszon, varigenom man i en enda operation ernhr selektiv sonderdelning av det bundna peroxi-syret till vatesuperoxid och utvinning av oforbrukad alkohol, keton saint en vattenlosning av vatesuperoxid. The process of the invention is carried out by subjecting the crude oxidation product to a controlled heat treatment and a rectification in a fractionation column under controlled operating conditions and throughput through the column. According to a preferred embodiment, the heat treatment and the rectification are carried out simultaneously in a rectification zone, whereby in a single operation a selective separation of the bound peroxy oxygen into hydrogen peroxide and recovery of unused alcohol, ketone saint an aqueous solution of hydrogen peroxide is performed.

Vid utforandet av forfaringssattet enligt uppfinningen underkastas den rha oxidationsprodukten med fordel en kontinuerlig fraktionerad destillation under i huvudsak konstanta forhallanden av vatskejamvikt i en fraktioneringskolonn innefattande en rektifikationszon, en separeringszon under rektifikationszonen for samtidig beroring med kokande och aterflodande vatskeformig produkt och angor, som utvecklats darur. Metoden innefattar drift under kritiska, inbordes avpassade, reglerade betingelser av a) tryck (eller temperatur) inuti kolonnen och b) uppehallstid i kolonnen for den genom denna passerade vatskeformiga produkten. I kolonnen omvandlas bundet peroxi-syre, som.forefinnes i den i kolonnen inmatade oxidationsprodukten, till stor del, t. ex. i huvudsak helt, till vatesuperoxid. En angfraktion innehallande sekundar alkohol, keton och vatten uttages kontinuerligt nara kolonnens ovre ande, och vattenhaltig flytande produkt innehallande vatesuperoxid samt betydligt minskad och fOr manga andamal fOrsumbar eller obefintlig halt av bundet peroxi-syre och andra organiska aninen uttages kontinuerligt, nara kolonnens botten. In carrying out the process according to the invention, the crude oxidation product is advantageously subjected to a continuous fractional distillation under substantially constant conditions of vatskjam weight in a fractionation column comprising a rectification zone, a separation zone under the rectification zone for simultaneous contact with boiling and refluxing drought. The method involves operation under critical, inboard-adjusted, controlled conditions of a) pressure (or temperature) within the column and b) residence time in the column of the liquid product passed through it. In the column, bound peroxyacid, which is present in the oxidation product fed into the column, is largely converted, e.g. essentially completely, to hydrogen superoxide. A vapor fraction containing seconds of alcohol, ketone and water is continuously withdrawn near the top of the column, and aqueous liquid product containing hydrogen peroxide and significantly reduced and for many purposes negligible or non-existent content of bound peroxyacid and other organic anines is continuously withdrawn from the near bottom of the column.

Den i kolonnen inforda produkten bor innehalla en shdan mangd vatten, att den vatskeformiga bottenprodukten fran kolonnen innehaller frail omkring 5 till omkring 35 vikt% vatesuperoxid. Enar de lagre sekundara alkoholerna bilda azeotropa blandningar med vatten, maste den i kolonnen inforda oxidationsprodukten innehalla tillrackligt med vat-ten for att tillhandahalla vatten for den vid lagsta temperaturen kokande vatten-azeotropen av den i produkten forefintliga alkoholen — —3 och dessutom en mangd vatten uppgaende till Fran 19 till 1,85 och foretradesvis fran 9 till 2,34 ganger vikten av det aktiva syret uttryckt sasom vatesuperoxid i den i kolonnen inmalade oxidationsprodukten. Typiska i kolonnen inforda blandningar innehalla frail 20 och upp till 60 vikt% vatten. Den ran oxidationsprodukten bor, om den icke innehaller tillrackligt med vatten for att fylla ovanstaende krav, spadas med vatten innan den infores i kolonnen, varvid mangden tillsatsvatten latt kan utraknas i varje enskilt fall pa basis av mangderna sekundar alkohol, aktivt syre °eh vatten i den raa oxidationsprodukten och sammansattningarna av den angformiga Ovre fraktionen och den vatskeformiga bottenprodukten, som uttagas ur kolonnen. The product introduced into the column should contain such an amount of water that the liquid bottom product from the column contains from about 5% to about 35% by weight of hydrogen peroxide. If the lower secondary alcohols form azeotropic mixtures with water, the oxidation product introduced into the column must contain sufficient water to provide water for the lowest boiling water azeotrope of the alcohol present in the product and a large amount of water. ranging from Fran 19 to 1.85 and preferably from 9 to 2.34 times the weight of the active oxygen expressed as hydrogen peroxide in the oxidation product ground in the column. Typical columns introduced in the column contain frail 20 and up to 60% by weight of water. The crude oxidation product, if it does not contain sufficient water to meet the above requirements, should be diluted with water before being introduced into the column, the amount of additional water being easily calculated in each case on the basis of the amounts of seconds of alcohol, active oxygen and water in the crude oxidation product and the compositions of the vaporous upper fraction and the liquid bottom product taken out of the column.

Oxidationsprodukten inf8res i kolonnen i flytande form. Temperaturen hos densamma installes nara temperaturen hos vatskan pa inforingsbottnen i kolonnen. Den. forvarmda produkten kan aven inforas i kolonnen delvis eller helt i angformigt tillstand. Sâ t. ex. kan det vara onskvart att befria produkten fran eventuella spar av metalliska fororeningar innan den infores i kolonnen. Detta kan ske genom snabbforangning av produkten och inforande av den forangade raa oxidationsprodukten i kolonnen licit eller delvis i angtillstand. The oxidation product is introduced into the column in liquid form. The temperature of the same is installed near the temperature of the liquid on the insertion bottom of the column. The. the preheated product can also be introduced into the column in part or in full in an angular state. For example. it may be unwise to rid the product of any traces of metallic contaminants before it is introduced into the column. This can be done by rapid evaporation of the product and introduction of the evaporated crude oxidation product into the licit column or partially in the state of anxiety.

Oxidationsprodukten infores kontinuerligt i kolonnen vid en mellanliggande punkt av denna. En vatskeformig del air produkten strommar nedat genom kolonnen i motstromskontakt med uppatstigande angor, som utveeklas ur den nedatstrommande vatskan under aterflOdes- och atcrkokningsbetingelscr. Sekundar alkohol och keton separeras eller avdestilleras frail den nedatstrommande vatskan. Samtidigt omvandlas det bundna peroxisyret selektivt till aktivt syre, som foreligger i en med kalk reaktionsbenagen form, dvs. till vatesuperoxid, och flyktiga organiska amnen, som uppstâ vid denna omvandling, avdestilleras i den man de bildas. Den nedatstrommande vatskan samlar sig i kolonnens undre del, fran vilken den uttages kontinuerligt i form av den onskade vattenlosningen av vatesuperoxid. The oxidation product is continuously introduced into the column at an intermediate point thereof. A liquid portion of the product flows downwardly through the column in countercurrent contact with ascending vapor, which is discharged from the downflowing liquid under reflux and reflux conditions. Seconds of alcohol and ketone are separated or distilled from the downwardly flowing liquid. At the same time, the bound peroxyacid is selectively converted to active oxygen, which is present in a form reacted with lime, i.e. to hydrogen superoxide, and volatile organic substances arising from this conversion are distilled off in the man in which they are formed. The downwardly flowing liquid collects in the lower part of the column, from which it is taken out continuously in the form of the desired aqueous solution of hydrogen peroxide.

Flyktiga amnen, som annars skulle medfolja den byre angformiga fraktionen frail kolonnen, kvarhallas genom att man leder angorna fran separeringszonen uppat genom rektifikationszonen och i motstrom mot och i huvudsaklig ang-vatske-j amvikt med kokande aterflodesvatska. Aterflodesvatskan utgores av vatskeformigt kondensat, som strommar neat fran hogre stallen i kolonnen. Flyktiga amnen, som vid lagre driftstryck eller i varo av rektifikationen i rektifikationszonen skulle avga upptill med den angformiga fraktionen fran kolonnen, kvarhallas salunda i kolonnen. Dessa flyktiga amnen innefatta flyktigt bundet peroxi-syre, som kvarhalles i ko- lonnen och i denna omvandlas till mindre flyktig vatesuperoxid. Forutom inre aterflodesvatska är oxen anordnat ett yttre vitsked.terlopp. Delta sker genom att aterfora en del av den kondenserade Ovre angformiga fraktionen till Ovre anden av fraktioneringszonen. Aterflodesforhallanden av minst omkring 0,2 (forhallande mellan volymen av aterford kondenserad, upptill uttagen fraktion och volymen av uttagen produkt) anvandas. Hogre aterflodesforhallanden, namligen upp till 4 eller darutover, kunna anvandas. The volatiles, which would otherwise accompany the byre angular fraction from the column, are retained by passing the vapors from the separation zone upwards through the rectification zone and in countercurrent to and in the main ang-liquid equilibrium with boiling reflux water. The re-flood water consists of liquid-shaped condensate, which flows neatly from the higher stables in the column. Volatile substances which, at lower operating pressures or in the presence of the rectification in the rectification zone, would emit at the top with the angular fraction from the column, are thus retained in the column. These volatile substances comprise volatile bound peroxy-oxygen, which is retained in the column and in this is converted into less volatile hydrogen peroxide. In addition to the inner white river, the ox is provided with an outer white spoon. Delta takes place by returning a part of the condensed Upper Ang-shaped fraction to the Upper spirit of the fractionation zone. The backflow ratio of at least about 0.2 (ratio between the volume of aterford condensed, top extracted fraction and the volume of withdrawn product) is used. Higher flood conditions, namely up to 4 or more, can be used.

Tryck (matta i byre delen air kolonnen) mom omradet 400-700 mm Hg anvandas beroende pa den speciella oxidationsprodukt, som behandlas i kolonnen, uppehallstiden och Onskad koncentration av vatesuperoxid i den vid kolonnens undre ande uttagna vatskeformiga produkten. Flyktigheten och stabiliteten hos de organiska peroxidkomponenterna ha befunnits mama sadana, att yid lagre tryck an omkring 400 ram Hg markbara mangder av aktivt syre tendera att fans Over i den Ovre fraktionen. A andra sidan leda vid tryck avsevart Over 700 mm Hg de erforderliga hOga destillationstemperaturerna till overdriven forlust av vatesuperoxid genom sonderdelning eller reaktion med de organiska amnen, som farefinnas i kolonnen. Dâ den sekundara alkoholen utgores av den foredragna isopropylalkoholen, dro tryck fran omkring 550 till omkring 700 mm Hg onskvarda. Enar det fOreligger en liten positiv tryckskillnad mellan kolonnens ovre ande och botten, kommer trycket vid kolonnens botten att vara exempelvis 25-75 mm hogre an trycket i kolonnens Ovre del. Da hdr tales om tryck inuti kolonnen, avses det tryck, som uppmates i kolonnens Ovre del. Temperaturerna i kolonnen komma att variera Mom granser overensstammande med trycket och den speciella oxidationsprodukt, som behandlas, och variera fran en minimitemperatur ay 55° C, matt yid kolonnens Ovre ande, till en maximitemperatur air 120° C matt vid kolonnens botten. Temperaturen pa den kokande vattenlosningen av vatesuperoxid i kolonnens kokarsektion beror pa 15sningens koncentration liksom pa trycket. Kolonnen b5r drivas yid sadana tryck och vdtesuperoxidkoncentrationer i kokarsektionen, att losningen av vatesuperoxid dar kokar Mom omradet 85-120° C. Pressure (mat in the upper part of the air column) with a range of 400-700 mm Hg is used depending on the special oxidation product, which is treated in the column, the residence time and the undesired concentration of hydrogen peroxide in the liquid product taken out at the bottom of the column. The volatility and stability of the organic peroxide components have been found to be such that yid lower pressures of about 400 ram Hg marked amounts of active oxygen tend to fans Over in the Upper fraction. On the other hand, at pressures above 700 mm Hg, the required high distillation temperatures lead to excessive loss of hydrogen peroxide by probing or reaction with the organic substances present in the column. As the secondary alcohol is the preferred isopropyl alcohol, pressures range from about 550 to about 700 mm Hg. If there is a small positive pressure difference between the upper spirit of the column and the bottom, the pressure at the bottom of the column will be, for example, 25-75 mm higher than the pressure in the upper part of the column. When hdr refers to pressure inside the column, it refers to the pressure that is applied in the upper part of the column. The temperatures in the column will vary depending on the pressure and the particular oxidation product being treated, and will vary from a minimum temperature of 55 ° C, matt above the upper spirit of the column, to a maximum temperature of 120 ° C matt at the bottom of the column. The temperature of the boiling aqueous solution of hydrogen peroxide in the boiling section of the column depends on the concentration of the solution as well as on the pressure. The column should be operated at such pressures and hydrogen superoxide concentrations in the boiler section that the solution of hydrogen superoxide boils in the Mom range of 85-120 ° C.

Genom reglering av inforingshastigheten for den rha oxidationsprodukten for ernaende ay en uppehallstid for denna produkt i kolonnen mom bestamda kritiska grainer regleras f8rloppet av omvandlingarna och separationerna i kolonnen pa sadant satt, att man ernar huvudsak kvantitativ utvinning i form av vatesuperoxid av det aktiva syret (peroxisyret) i den i kolonnen inforda oxidationsprodukten. Uppehallstiden kan definieras sasom kvoten mellan volymen av vatskeinnehallet i kolonnen (inklusive kokaren) och info- — — ringshastigheten f6r den vatskeformiga produktens i kolonnen. Uppehallstiden, som for .ernaende av optimala utbyten av vatesupercaid i viss utstrackning beror pa arten av den kolonnen inforda oxidationsprodukten och temperaturen i kokar- och separeringssektionerna i kolonnen, b8r icke overstiga 100 minuter. Uppehallstider Mom omradet 10-30 minuter aro vanligen optimala. Raa produkter fran partiell oxidation air isopropylalkohol innehallande mellan 10 och 40 % av det totala aktiva syret i form av bun:det peroxi-syre, varvid resten utgores av vatesuperoxid, ha behandlats enligt uppfinningen vid tryck i kolonnen mellan 550 och 675 mm Hg och vid uppehallstider mellan 10 och 30 minuter med utbyten air vatesuperoxid sá hoga som 97.99 % raknat pa totala mangden aktivt syre i den i kolonnen inforda oxidationsprodukten, innebarande utbyten air vatesuperoxid raknat pa mangden av vatesuperoxid i den i kolonnen inforda oxidationsprodukten betydligt overstigande 100 7',0 Omvandlingen av det bundna peroxi-syret och rektifikationen utforas samtidigt. I vissa fall kan en partiell omvandling av det bundna peroxi-syret till vatesuperoxid foretagas i ett sarskilt, forberedande steg, varefter den atersthende delen air det bundna peroxi-syret omvandlas genom kontinuerlig rektifikation av den resulterande blandningen. SO. t. ex. kan man upphetta den rda oxidationsprodukten i on tank, varmevaxlare eller annat lampligt karl till temperaturer mellan 75 och 120° C under en tid av upp till omkring 1 timme tillracklig for astadkommande av en partiell omvandling av det bundna peroxi-syret till vatesuperoxid. Den raa oxidationsprodukten innehallande den aterstaende delen av det bundna peroxi-syret, vatesuperoxid, sekundar alkohol, keton °eh vatten kan darefter kontinuerligt inforas i rektifikationskolonnen och underkastas kontinuerlig rektifikation, sa att den aterstaende delen av det bundna peroxisyret omvandlas till vatesuperoxid samtidigt med retifikationen air blandningen for utvinning av alkoholen, ketonen och vattenhaltig yatesuperoxidlOsning. By controlling the rate of introduction of the crude oxidation product to a critical residence time for this product in the column defined in the column, the course of the transformations and separations in the column is regulated in such a way as to obtain mainly quantitative recovery in the form of hydrogen peroxide of the active oxygen. ) in the oxidation product introduced into the column. The residence time can be defined as the ratio between the volume of the liquid content in the column (including the digester) and the infeed rate of the liquid product in the column. The residence time, which in order to obtain optimal yields of hydrogen supercide to some extent depends on the nature of the oxidation product introduced into the column and the temperature in the boiler and separation sections of the column, should not exceed 100 minutes. Residence times Mom in the range of 10-30 minutes are usually optimal. Raw products of partial oxidation of air isopropyl alcohol containing between 10 and 40% of the total active oxygen in the form of bun: the peroxy oxygen, the remainder being hydrogen peroxide, have been treated according to the invention at pressures in the column between 550 and 675 mm Hg and at residence times between 10 and 30 minutes with yields of hydrogen peroxide as high as 97.99% calculated on the total amount of active oxygen in the oxidation product introduced into the column, i.e. yields of hydrogen peroxide calculated on the amount of hydrogen peroxide in the oxidation product introduced in the column significantly exceeding 100 The conversion of the bound peroxy oxygen and the rectification are carried out simultaneously. In some cases, a partial conversion of the bound peroxy oxygen to hydrogen peroxide may be carried out in a separate, preparatory step, after which the remaining part of the bound peroxy oxygen is converted by continuous rectification of the resulting mixture. SO. e.g. For example, the red oxidation product can be heated in a tank, heat exchanger or other suitable vessel to temperatures between 75 and 120 ° C for a period of up to about 1 hour sufficient to effect a partial conversion of the bound peroxy oxygen to hydrogen peroxide. The crude oxidation product containing the remaining part of the bound peroxyacid, hydrogen superoxide, secondary alcohol, ketone or water can then be continuously introduced into the rectification column and subjected to continuous rectification, so that the remaining part of the bound peroxyacid is converted to the hydrogen peroxide at the same time as the hydrogen peroxide. the mixture for the recovery of the alcohol, the ketone and aqueous yate superoxide solution.

Den vattenlosning air vatesuperoxid, som erMlles vid utforande av forfarandet enligt uppfinningen, är en i och for sig anvandbar produkt, och i manga fall kan den auvandas for det avsedda syftet utan ytterligare rening och/ eller koncentration. Da man Onskar ytterligare rena och/eller koncentrera denna losning, kan sadan rening och/eller koncentrering utforas pa vilket som heist kant salt. The aqueous solution of hydrogen superoxide obtained in carrying out the process according to the invention is a product which can be used per se, and in many cases it can be used for the intended purpose without further purification and / or concentration. When it is desired to further purify and / or concentrate this solution, such purification and / or concentration can be carried out on any hot salt.

Den upptill Iran kolonnen avgaende fraktionen ledes i kretslopp, sa att den oforbrukade alkoholen aterfOres till oxidations steget for framstallning av ytterligare mangder vatesuperoxid, och ketonen hydreras till den sekundara alkohol, som an-vandes sasom utgangsmaterial. En av fordelarna med uppfin ningen bestar i att denna kretsprocess i hog grad underlattas genom att den upptill ut- tagna fraktionen är fri Iran flyktiga peroxisyreforeningar, som tendera att inaktivera hydreringskatalysatorn. Den upptill uttagna fraktionen innefattande alkohol-vatten-azeotrop och keton-biprodukt kan inforas direkt i hydreringsapparaten, i vilken den fores i beroring med gasformigt vate och en hydreringskatalysator under hydreramle betingelser eventuellt efter foreghende fraktionering for att separera all alkohol eller en del av alkoholen frail ketonen, innan denna sistnamnda hydreras. Den fran hydreringsapparaten utgaende produkten kan destilleras f8r atervinning av icke omvandlad keton, vilken aterfores till hydreringsapparaten. Den sekundara alkoholen kan aterf8ras fran destillationsapparaturen till oxidationssteget med tillsats av ytterligare alkohol. The fraction extending up to the Iran column is circulated so that the crude alcohol is returned to the oxidation step to produce additional amounts of hydrogen peroxide, and the ketone is hydrogenated to the secondary alcohol used as starting material. One of the advantages of the invention is that this circuit process is greatly facilitated by the fact that the fraction taken at the top is free Iran volatile peroxyacid compounds, which tend to inactivate the hydrogenation catalyst. The fraction taken from the top comprising alcohol-water-azeotrope and ketone by-product can be introduced directly into the hydrogenation apparatus, in which it is contacted with gaseous hydrogen and a hydrogenation catalyst under hydrothermal conditions, optionally after previous fractionation to separate all alcohol or part of the alcohol. the ketone, before the latter is hydrogenated. The product leaving the hydrator can be distilled to recover unconverted ketone, which is recycled to the hydrator. The secondary alcohol can be returned from the distillation apparatus to the oxidation step with the addition of additional alcohol.

Uppfinningen shall i det foljande beskrivas i saraband med en kontinuerlig process fOr framstallning air vatesuperoxid med anvandande av den apparatur, som visas a bifogade riffling. The invention will now be described in conjunction with a continuous process for the production of hydrogen peroxide using the apparatus shown in the accompanying rifling.

Vid processen infores lagre sekundar alkohol, t. ex. isopropylalkohol, innehallande en liten mangd, t. ex. 500 delar per million av tillsatt stabilisator far vatesuperoxid, sasom kaliumpyrofosfat, i reaktorn 1 genom inloppet 2. Till den ursprungliga satsen air alkoholen sattes en ringa mangd, exempelvis omkring 1 vikt %, vatesuperoxid eller organisk peroxid, sasom di-tert.-butylperoxid. Alkoholen behandlas med en shorn air gas innehallande molekylart syre, t. ex. luft, som infores under tryck och i overskott genom inloppet 3 och bringas i intim kontakt med den vatskeformiga alkoholen. Avgaser utslappas genom ett avlopp 4 och en aterflodeskylare 5. Innehallet i reaktorn omrores medelst ett rorverk 6. Reaktionstemperaturen kan ligga mellan 100° C och 160° C, och en temperatur av 130° C är synnerligen lamplig. 'S/id kontinuerlig tillforsel av sekundar alkohol till reaktorn och sedan normal drift uppnatts uttages en oxidationsprodukt, innehallande of orbrukad alkohol, motsvarande keton, vatesuperoxid och bundet peroxi-syre, genom avloppet 7, kyles i en varmevaxlare 8 och fares genom en ledning till en perkolator 10. I perkolatorn fores produkten fran reaktorn i beroring med ett katjonutbytande harts av en typ, som formar avlagsna spar av tungmetalljoner. During the process, lower secondary alcohol is introduced, e.g. isopropyl alcohol, containing a small amount, e.g. 500 parts per million of added stabilizer for hydrogen peroxide, such as potassium pyrophosphate, in reactor 1 through inlet 2. To the original batch of air alcohol was added a small amount, for example about 1% by weight, of hydrogen peroxide or organic peroxide, such as di-tert-butyl peroxide. The alcohol is treated with a shorn air gas containing molecular oxygen, e.g. air, which is introduced under pressure and in excess through the inlet 3 and brought into intimate contact with the liquid alcohol. Exhaust gases are discharged through a drain 4 and a backflow cooler 5. The contents of the reactor are stirred by means of a stirrer 6. The reaction temperature can be between 100 ° C and 160 ° C, and a temperature of 130 ° C is extremely suitable. In the continuous supply of secondary alcohol to the reactor and after normal operation has been reached, an oxidation product, containing unused alcohol, corresponding to ketone, hydrogen peroxide and bound peroxyacid, is taken out through the drain 7, cooled in a heat exchanger 8 and passed through a line to a percolator 10. In the percolator, the product from the reactor is brought into contact with a cation exchange resin of a type which forms deposited traces of heavy metal ions.

Den med harts behandlade oxidationsprodukten fares via en ledning 11 till en mellanliggande niva i en kolonn 12. I kolonnen 12 uttagas upptill genom ledningen 13 oforbrukad alkohol samt keton-biprodukt, och forhandenvarande bundet peroxi-syre omvandlas samtidigt och selektivt till vatesuperoxid, som uttages sasom bottenprodukt ur kolonnen via a-vloppet 14. I beroende air onskad koncentralion av H2O2 i denna produkt samt koncentra- — — tionen av vatten i oxidationsprodukten fran reaktorn 1 kan utspadningsvatten tillsattas till reaktionsprodukten fore fraktioneringen, exexpelvis genom inloppet 15. The resin-treated oxidation product is passed via a line 11 to an intermediate level in a column 12. In the column 12, unused alcohol and ketone by-product are taken out through the line 13, and any bound peroxyacid is converted simultaneously and selectively to hydrogen superoxide, which is taken as bottom product from the column via the α-stream 14. Depending on the desired concentration of H2O2 in this product and the concentration of water in the oxidation product from the reactor 1, dilution water can be added to the reaction product before the fractionation, for example through the inlet 15.

Kolonnen 12 kan Tara av bruklig konstruktion forsedd med klockbottnar, gallertrag, silbottnar eller darmed ekvivalenta anordningar. Kolonnen dr upptill ansluten till en kondensor 16 med aterflOdestrumma 17 och returledning 18 samt forsedd med kokare 19 och returledning 20. Den bar vara konstruerad for effektiv separering av vatten och alkohol-vatten-azeotropen av den anvanda lagre sekundara alkoholen, och vidare maste den lampa sig for arbete vid de tryck och de uppehallstider, som erfordras i fraktioneringssteget enligt uppfinningen. Kolonnen bar vara framstalld av eller atminstone fodrad med ett material, som är inert gentemot vatesuperoxid, sasom glas, keramiskt material, icke rostande metall, sasom tenn, tantal eller vissa slag av rostfria sta.' eller aluminium. Column 12 can Tara of conventional construction provided with bell bottoms, grid trays, screen bottoms or thus equivalent devices. The column at the top is connected to a condenser 16 with reflux drum 17 and return line 18 and provided with a boiler 19 and return line 20. It should be designed for efficient separation of water and the alcohol-water azeotrope of the lower secondary alcohol used, and furthermore the lamp for work at the pressures and residence times required in the fractionation step according to the invention. The column should be made of or at least lined with a material which is inert to hydrogen superoxide, such as glass, ceramic, non-rusting metal, such as tin, tantalum or certain types of stainless steel. ' or aluminum.

Oxidationsprodukten infores kontinuerligt i kolonnen i &Man mangd, att uppehallstiden dari fOr den valskeformiga delen av produkten icke overstiger 100 minuter och foretradesvis uppgar till 10-30 minuter. Try&et i kolonnen balks genom vakuumpumpar mom omradet 400-700 mm Hg och installes i enlighet med vattenkoncentrationen i den MIMI.- da oxidationsprodukten och den onskade vatesuperoxidkoncentrationen i botienfraktionen frail kolonnen. Vid vissa oxidationsprodukter kan koncentrationen av polymera organiska peroxider samt flyktigheten och losligheten av dessa vara sadana, att sma mangder av en separat och pa organiska peroxider rik fas kan bildas pa en eller flera bottnar i kolonnen. For att unthika en eventuellt haftig sonderdelning av de organiska peroxiderna i denna f as, kan densamma uttagas ur kolonnen vid den eller de bottnar, pa vilka den samlas, genom en. lamplig uttagsledning, varvid vatskan frail denna botten fOres till en utanfor kolonnen beldgen separeringsanordning, i vilken de polymera peroxiderna separeras och avlagsnas ur systemet. Andra likvardiga medel kunna avenledes anvandas harfor. The oxidation product is continuously introduced into the column in such a way that the residence time for the roller-shaped part of the product does not exceed 100 minutes and preferably amounts to 10-30 minutes. The pressure in the column is balked by vacuum pumps in the range 400-700 mm Hg and installed in accordance with the water concentration in the MIMI.- oxidation product and the desired hydrogen superoxide concentration in the botien fraction frail column. In the case of certain oxidation products, the concentration of polymeric organic peroxides and their volatility and solubility may be such that small amounts of a separate phase rich in organic peroxides may form on one or more bottoms of the column. In order to avoid a possible severe separation of the organic peroxides in this phase, it can be removed from the column at the bottom or bottoms on which it accumulates, through a. suitable outlet line, the liquid from this bottom being fed to an outside column beldgen separating device, in which the polymeric peroxides are separated and removed from the system. Other equivalent means can also be used here.

Den upptill fran kolonnen 12 avgaende produkten bestaende vasentligen ax alkohol-vatten-azeotrop och keton uttages kontinuerligt och fores till en hydreringsapparat 21 via en ledning 22, en forangare 23 och ledning 22a. Vale infores genom en ledning 24 och hydrering sker i apparaten Over en hydreringskatalysator, sasom en nickel-, jam-, koppar-, kobolt- eller platinakatalysator eller annan lamplig katalysator. Katalysatorn kan med fOrdel utgoras av en nickelkatalysator innehallande 40-60 vikt % nickel uppburet av ett inert mineraliskt barande material, sasom diatornacejord, kiseldioxid etc. Hydreringstemperaturen kan ligga exempelvis mellan 25° C och 150° C och vatgastryck upp till 350 kg/cm2 kunna anvandas. The product consisting essentially of the column 12 consisting essentially of alcohol-water-azeotrope and ketone is continuously withdrawn and fed to a hydrator 21 via a line 22, an evaporator 23 and line 22a. Vale is introduced through a line 24 and hydrogenation takes place in the apparatus via a hydrogenation catalyst, such as a nickel, jam, copper, cobalt or platinum catalyst or other suitable catalyst. The catalyst can advantageously consist of a nickel catalyst containing 40-60% by weight of nickel supported by an inert mineral-bearing material, such as diatomaceous earth, silica, etc. The hydrogenation temperature can be between 25 ° C and 150 ° C, for example, and water pressure up to 350 kg / cm 2 can used.

Fran hydreringsapparaten 21 fares den avgaende produkten genom ledningen 25, kondensorn. 26, ledningen 27, separatorn 28 och ledningen 29 till kolonnen 30, som dr fOrsedd med aterflodeskylare 31, aterflodestrumma 32 och kokare 33. I kolonnen 30 kan i produkten fran separatorn 28 eventuellt forefintlig, icke om.vandlad keton separeras och uttagas upptill samt aterforas till hydreringsapparaten genom ledningen 34. Mervunnen sekundar alkohol kan foras tillbaka direkt till reaktorn 1 genom ledningen 35 eller om sa Onskas fraktioneras, exempelvis i syfte att darur avlagsna en del av vattnet for att erhalla en produkt med lagre vattenhalt for aterinfOrande i kretsloppet eller for avlagsnande av spar av fororeningar, sasom tungmetalljoner, Foljande exempel askadliggiir mera i detalj en utforingsform av uppfinningen. I exemplet avse deter och procentsatser viktdelar respektive viktprocent, savida kite annat an-gives. From the hydrator 21, the effluent is passed through the line 25, the condenser. 26, line 27, separator 28 and line 29 to column 30, which is provided with reflux condenser 31, reflux drum 32 and boiler 33. In column 30 the product from separator 28, if any, unconverted ketone may be separated and removed at the top and refilled. to the hydrator through line 34. Recovered second alcohol can be returned directly to reactor 1 through line 35 or if so desired to be fractionated, for example for the purpose of removing some of the water therefrom to obtain a lower water product for re-introduction into the cycle or for removal. of traces of impurities, such as heavy metal ions, The following examples illustrate in more detail an embodiment of the invention. In the example, deter and percentages refer to parts by weight and percentages by weight, respectively, unless otherwise stated.

Exempel. Example.

En râ oxidationsprodukt framstalldes ge, nom att i vatskefas och i ursprunglig narvaro av omkring 2 vikt% tillsatt vatesuperoxid partiellt oxidera isopropylalkohol innehallande 12,5 % vatten och 10-20 delar per million av natriumpyrofosfat. Den raa oxidationsprodukten inneholl raknat p. vattenfritt till-stand 5,6 % aktivt syre uttryckt sasom vatesuperoxid, omkring 45,8 % isopropylalkohol, omkring 11,9 % aceton och omkring 0,2 % av andra syrehaltiga organiska foreningar. Av totem a mangden aktivt syre forelag omkring 40 % i en med kalk icke reaktionsbenagen form. A crude oxidation product was prepared by partially oxidizing isopropyl alcohol containing 12.5% water and 10-20 parts per million of sodium pyrophosphate in the aqueous phase and in the initial presence of about 2% by weight of added hydrogen peroxide. The crude oxidation product contained, in the anhydrous state, 5.6% active oxygen expressed as hydrogen peroxide, about 45.8% isopropyl alcohol, about 11.9% acetone and about 0.2% of other oxygen-containing organic compounds. Of the totem in the amount of active acid, about 40% was present in a form unreacted with lime.

For fraktionering av den ran oxidationsprodukten anvandes en helt av glas bestaende kolonn med 35 perforerade bottnar och utrustad med en. av pyrex-glas utford kokare av termosifontyp, en ovre kondensor samt en valskedelande overdel med en solenoidreglerad anordning for reglering av aterflodesforhallandet. Trycket i kolonnen heals medelst en till den pa kolonnen anordnade kondensorn ansluten vakuumpump -vid 650 mm Hg. En kontinuerlig strom av ovannamnda raa oxidationsprodukt infordes i kolonnen vid den 25:e bottnen frail undre anden raknat och i en. mangd, som medfiirde en uppehallstid av vatskan i kolonnen pa 29 minuter. AterflodesfOrhallandet installdes pa 0,5 (5.terflode/ produkt). Da destillationen fortskred, uttogs en blandning av isopropylalkoh.ol-vatten-azeotrop och aceton kontinuerligt upptill och en omkr. 15 %-ig vattenlosning av vatesuperoxid uttogs fran kolonnens undre ande. Temperaturen pa losningen i kokaren vid denna koncentration och detta tryck uppgick till 101° C. Temperaturen i kolonnens ovre del uppgick 6— — till 74° C. Av totala mangden aktivt syre i den till kolonnen forda oxidationsprodukten atervanns, 96,1 % sasom vatesuperoxid i bottenprodukten fran kolonnen. Den utvunna vatesuperoxiden motsvarade ett utbyte av 160 % raknat pa vatesuperoxidhalten i den till kolonnen forda oxidationsprodukten. For fractionation of the crude oxidation product, an entirely glass column with perforated bottoms and equipped with one was used. of pyrex glass challenge thermosiphon type boilers, an upper condenser as well as a roller-chilling upper part with a solenoid-regulated device for regulating the return flow ratio. The pressure in the column is healed by means of a vacuum pump connected to the condenser arranged on the column - at 650 mm Hg. A continuous stream of the above-mentioned crude oxidation product was introduced into the column at the 25th bottom frail lower duck shaved and into a. amount, which resulted in a residence time of the liquid in the column of 29 minutes. The reflux ratio was set at 0.5 (5th reflux / product). As the distillation proceeded, a mixture of isopropyl alcohol-water-azeotrope and acetone was continuously withdrawn at the top and an approximately 15% aqueous solution of hydrogen peroxide was taken from the bottom of the column. The temperature of the solution in the digester at this concentration and this pressure was 101 ° C. The temperature in the upper part of the column was 6 to 74 ° C. Of the total amount of active oxygen in the oxidation product fed to the column, 96.1% as hydrogen superoxide was recovered. in the bottom product from the column. The hydrogen peroxide recovered corresponded to a 160% yield calculated on the hydrogen peroxide content of the oxidation product fed to the column.

Claims

Patent claim:

1. In the preparation of hydrogen superoxide by oxidation with oxygen of secondary alcohols in the liquid phase according to patent 175 715, characterized in that the oxidized reaction mixture is fed into a fractionation column at a point between its spirits, the temperature being matt at the 8th second of the column. Melt at at least 55 ° C and matt at the bottom at a maximum of 120 ° C saint pressure matt at the upper dude Hiles of the column between 400 and 700 mm Hg, while the temperature of the feed reaction mixture Mlles near the temperature at part of the column where the reaction mixture is fed, and wherein the water content of the mixture is adjusted so that the bottom fraction obtained during the rectification contains 5-35% by weight of hydrogen peroxide, the reaction mixture is rectified in the column for a residence time of up to 100 minutes, and alcohol and ketone formed during the oxidation are distilled off as a top fraction. aqueous solution containing 5-35% by weight of hydrogen peroxide is taken sa.- so m bottom fraction.

2. According to patent claim 1, characterized in that the reaction mixture is inadvertently freed from the usual traces of metallic impurities, e.g. by rapid evaporation followed by complete or partial condensation. 3. Set according to claim 1 or 2, characterized in that the top fraction is returned as flow back to the fractionation column in a return ratio of 0.2: 1. Set according to any of claims 13, characterized in that the top fraction is returned to the oxidation step then in the same existing ketone hydrogenated to secondary alcohol. Cited publications: Patents from Switzerland 140 084, 149 397, 208 527; Germany 199058, 219154, 877893, 888840; USA 2 479 111. Other publications: Beilstein's Handbuch der organischen Chemie, Hauptwerk, Volume 1 (Vierte Auflage, Berlin 1918), p. 645, 6th paragraph. Stockholm 196

3. Kungl. Boktr. P. A. Norstedt & StMer. 680081)