DK146651B

DK146651B - METHOD FOR PREPARING HYDROGEN PEROXIDE

Info

Publication number: DK146651B
Application number: DK375978AA
Authority: DK
Inventors: Bengt Gustaf Franzen
Original assignee: Elektrokemiska Ab
Priority date: 1977-08-26
Filing date: 1978-08-25
Publication date: 1983-11-28
Also published as: SE411745B; FI782554A; DK375978A; FI65608C; DK146651C; NO782840L; NO144260C; FI65608B; SE7709607L; NO144260B

Description

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§ (12) FREMLÆGGELSESSKRIFT od 146651 B§ (12) PUBLICATION MANUAL OR 146651 B

DIREKTORATET FOR PATENT-OG VAREMÆRKEVÆSENETPATENT AND TRADEMARKET DIRECTORATE

(21) Patentansøgning nr.: 3759/78 (51) lnt.CI.3: C01B 15/023 (22) Indleveringsdag: 25 aug 1978 (41) Aim. tilgængelig: 27 feb 1979 (44) Fremlagt: 28 nov 1983 (86) International ansøgning nr.: - (30) Prioritet: 26 aug 1977 SE 7709607 (71) Ansøger: *ELEKTROKEMISKA AKTIEBOLAGET; S-445 01 Suite 1, SE.(21) Patent Application No: 3759/78 (51) Lnt.CI.3: C01B 15/023 (22) Filing Date: 25 Aug 1978 (41) Aim. available: 27 Feb 1979 (44) Submitted: 28 Nov 1983 (86) International Application No: - (30) Priority: 26 Aug 1977 SE 7709607 (71) Applicant: * ELECTROCHEMICAL SHARE COMPANY; S-445 01 Suite 1, SE.

(72) Opfinder: Bengt Gustaf *Franzen; SE.(72) Inventor: Bengt Gustaf * Franzen; SEE.

(74) Fuldmægtig: Internationalt Patent-Bureau (54) Fremgangsmåde til fremstilling af hydrogenpero-xid(74) Plenipotentiary: International Patent Office (54) Process for the production of hydrogen peroxide

Den foreliggende opfindelse angår en fremgangsmåde til fremstilling af hydrogenperoxid ved anthraquinonprocessen, ved hvilken der som hovedsageligt opløsningsmiddel for anthraquinonerne anvendes benzencarbonhydrider, og denne fremgangsmåde er ejendommelig ved, at der som opløsningsmiddel for ved hydrogeneringen dannede hydro-generingsprødukter desuden i arbejdsopløsningen indgår mindst to højere, sekundære, alifatiske alkoholer, og at samtlige i arbejdsopløsningen indgående opløsningsmidler proportioneres således, at CD arbejdsopløsningens fordelingskoefficient bliver højre end 30 og JZ. lavere end 50.The present invention relates to a process for the production of hydrogen peroxide by the anthraquinone process, in which the main solvent for the anthraquinones is used benzene hydrocarbons, and this process is characterized in that, as a solvent for hydrogenation products formed during the hydrogenation, additionally is included in the working solution at least two higher. secondary aliphatic alcohols, and that all solvents contained in the working solution are proportioned so that the distribution coefficient of the CD working solution becomes higher than 30 and JZ. lower than 50.

io S Ved fremstilling af hydrogenperoxid efter den kendte anthra- ^ quinonproces hydrogeneres alkylanthraquinon og/eller tetrahydroan- T“ * Ω 2 146651 thraquinon og tetrahydroalkylanthraquinon opløst i organiske opløsningsmidler i nærværelse af en katalysator til tilsvarende anthrahydroquinoner. Efter at katalysatoren er fraskilt, oxideres anthra-hydroquinonerne med luft eller oxygengas, hvorved der opnås hydro-genperoxid, samtidig med at de oprindelige anthraquinoner gendannes. Hydrogenperoxidet ekstraheres med vand, hvorefter den såkaldte ar-bejdsopløsning tilbageføres til hydrogeneringstrinnet. Arbejdsopløs-ningen indeholder sædvanligvis mindst to typer opløsningsmiddel med forskellige egenskaber. Den ene type opløsningsmiddel skal kunne opløse et højt indhold af anthraquinoner. Dets evne til at opløse et tilsvarende højt indhold af anthrahydroquinoner er derimod oftest utilstrækkelig. Benzenderivater med 8-10 carbonatomer i molekylet har vist sig at være egnede opløsningsmidler for anthraquinoner og tetrahydroanthraquinoner. For at der ikke skal ske udfældning af anthrahydroquinoner i hydrogeneringstrinnet, anvendes der desuden en anden type opløsningsmiddel, en organisk væske, som relativt let opløser anthrahydroquinoner og tetrahydroanthrahydroquinoner. Højere alifatiske, sekundære alkoholer har vist sig at være tilstrækkelig gode opløsningsmidler til dette formål. Eksempler på sekundære alkoholer af denne art er alkoholer med 7-9 carbonatomer, såsom 4-hepta-nol, 2-octanol og 2,6-dimethyl-4-heptanol. Fremgangsmåder, i hvilke et aromatisk carbonhydrid anvendes sammen med en sekundær alifatisk alkohol, er kendte fra norsk patentskrift nr. 105.014.In the preparation of hydrogen peroxide following the known anthraquinone process, alkyl anthraquinone and / or tetrahydroan- T * * 2 146651 thraquinone and tetrahydroalkylanthraquinone are dissolved in organic solvents in the presence of a catalyst to corresponding anthrahydroquinones. After the catalyst is separated, the anthrahydroquinones are oxidized with air or oxygen gas to obtain hydrogen peroxide while recovering the original anthraquinones. The hydrogen peroxide is extracted with water and the so-called working solution is returned to the hydrogenation step. The working solution usually contains at least two types of solvent having different properties. One type of solvent should be able to dissolve a high content of anthraquinones. However, its ability to dissolve a similarly high content of anthrahydroquinones is usually insufficient. Benzene derivatives having 8-10 carbon atoms in the molecule have been found to be suitable solvents for anthraquinones and tetrahydroanthraquinones. In addition, in order not to precipitate anthrahydroquinones in the hydrogenation step, another type of solvent is used, an organic liquid which dissolves anthrahydroquinones and tetrahydroanthrahydroquinones relatively easily. Higher aliphatic secondary alcohols have been found to be sufficiently good solvents for this purpose. Examples of secondary alcohols of this kind are alcohols having 7-9 carbon atoms, such as 4-heptanol, 2-octanol and 2,6-dimethyl-4-heptanol. Methods in which an aromatic hydrocarbon is used with a secondary aliphatic alcohol are known from Norwegian Patent Specification No. 105,014.

Til arbejdsopløsningen og opløsningsmidlet stilles der flere fordringer, hvoraf flertallet er angivet i f.eks. svensk patentskrift nr. 340.442. Imidlertid omtales det ikke i dette patentskrift, at fordelingskoefficienten for hydrogenperoxid i forhold til arbejdsopløsningen og en vandfase bør have en med hensyn til arbejdsopløsnin-gens produktivitet og processens sikkerhed passende størrelse. Med fordelingskoefficienten menes forholdet mellem gram hydrogenperoxid pr. liter i vandfasen og den tilsvarende koncentration i den organiske væskefase ved ligevægt. Ved arbejdsopløsningens produktivitet menes det indhold af hydrogenperoxid udtrykt i gram pr. liter, som arbejdsopløsningen i praktisk drift højest kan indeholde efter oxidationen. Dette indhold beror på arbejdsopløsningens totale sammensætning, som det f.eks. er vist i vesttysk fremlæggelsesskrift nr. 1.112.051.Several claims are made for the working solution and the solvent, the majority of which are stated in e.g. Swedish Patent Specification No. 340,442. However, it is not mentioned in this patent that the distribution coefficient of hydrogen peroxide relative to the working solution and an aqueous phase should be of adequate size in terms of the productivity of the working solution and the safety of the process. By the distribution coefficient is meant the ratio of grams of hydrogen peroxide per liter. liters in the aqueous phase and the corresponding concentration in the organic liquid phase at equilibrium. By the productivity of the working solution is meant the content of hydrogen peroxide expressed in grams per gram. per liter, which in practical operation can contain the highest after the oxidation. This content depends on the total composition of the working solution, as it is e.g. is shown in West German Petition No. 1,122,051.

En høj fordelingskoefficient hos arbejdsopløsningen er gunstig ved ekstraktionen. Denne muliggør, at vandekstrakten kan få et højt hydrogenperoxidindhold. En alt for høj fordelingskoefficient i kombi- 3 146651 nation med et givet indhold af hydrogenperoxid i arbejdsopløsningen kan imidlertid være risikabel, dersom der opstår en mindre mængde vandfase i arbejdsopløsningen før ekstraktionen. En sådan vandfase kan eksempelvis dannes ved, at hydrogenperoxid sønderdeles til vand og oxygen. Fordelingskoefficienten multipliceret med gram hydrogenperoxid pr. liter arbejdsopløsning bør ikke i væsentlig grad overstige 600. Dvs., at det højest mulige hydrogenperoxidindhold i vandfasen ikke bør være højere end ca. 600 gram pr. liter I modsat fald foreligger der risiko for eksplosiv reaktion mellem vandfasen og den organiske fase.A high coefficient of distribution of the working solution is favorable for the extraction. This allows the water extract to have a high hydrogen peroxide content. However, a too high partition coefficient in combination with a given hydrogen peroxide content in the working solution can be risky if a small amount of aqueous phase in the working solution occurs before extraction. Such an aqueous phase can be formed, for example, by decomposing hydrogen peroxide into water and oxygen. The partition coefficient multiplied by grams of hydrogen peroxide per liter of working solution should not substantially exceed 600. That is, the highest possible hydrogen peroxide content in the aqueous phase should not be higher than approx. 600 grams per Otherwise there is a risk of an explosive reaction between the aqueous phase and the organic phase.

De benzenderivater, der kan anvendes som opløsningsmiddel for anthraquinon, har en fordelingskoefficient, der går op til 2000-3000. Fordelingskoefficienten for de alifatiske, sekundære alkoholer, der anvendes som opløsningsmiddel for anthrahydroquinoner, er imidlertid betydeligt lavere. 2-0ctanol har eksempelvis fordelingskoefficienten 11.The benzene derivatives which can be used as a solvent for anthraquinone have a distribution coefficient of up to 2000-3000. However, the coefficient of distribution of the aliphatic secondary alcohols used as a solvent for anthrahydroquinones is significantly lower. 2-0ctanol, for example, has the partition coefficient 11.

For at koncentrationen af anthraquinoner i den oxiderede arbejdsopløsning skal være høj, må sædvanligvis ca. 50 vol% af opløsningsmiddelindholdet bestå af aromatiske carbonhydrider. Dersom resten er 2-octanol, bliver blandingens fordelingskoefficient ca. 30.In order for the concentration of anthraquinones in the oxidized working solution to be high, usually approx. 50% by volume of the solvent content consists of aromatic hydrocarbons. If the residue is 2-octanol, the partition coefficient of the mixture becomes approx. 30th

I en sådan arbejdsopløsning med fordelingskoefficienten 30 er f.eks. sammensætningen for øvrigt sådan, at indholdet af hydrogenperoxid efter oxidationen ikke kan være højere end 14 gram pr. liter. Den højest mulige hydrogenperoxidkoncentration i vandekstrakten bliver da 420 gram pr. liter, hvilket er utilfredsstillende. Erstattes opløsningsmidlet 2-octanol helt med 2,6-dimethyl-4-heptanol, bliver fordelingskoefficienten ca. 50. Hydrogenperoxidindholdet i vandfasen kan da blive 700 gram pr. liter, hvilket kan være risikabelt.In such a working solution with the distribution coefficient 30, e.g. the composition, moreover, such that the content of hydrogen peroxide after the oxidation cannot be higher than 14 grams per liter. liter. The highest possible hydrogen peroxide concentration in the water extract will then be 420 grams per minute. liter, which is unsatisfactory. If the solvent 2-octanol is completely replaced with 2,6-dimethyl-4-heptanol, the partition coefficient will be approx. 50. The hydrogen peroxide content in the aqueous phase can then be 700 grams per liter. liter, which can be risky.

Fremgangsmåden ifølge den foreliggende opfindelse udføres ved, at anthraquinoner og tetrahydroanthraquinoner, som er opløst i opløsningsmidler, hydrogeneres, de opnåede hydrogeneringsprodukter oxideres og ved oxidationen dannet hydrogenperoxid ekstraheres med vand. Som nævnt anvendes der som opløsningsmiddel for de ved . hydrogeneringen dannede hydroquinoner mindst to højere, sekundære, alifatiske alkoholer. Eksempler på sekundære, alifatiske alkoholer, der kan anvendes ifølge opfindelsen, er alkoholer med 7-9 carbonato-mer. Specielt skal der nævnes 2-octanol og 2,6-dimethyl-4-heptanol.The process of the present invention is carried out by hydrogenating anthraquinones and tetrahydroanthraquinones dissolved in solvents, oxidizing the obtained hydrogenation products and extracting hydrogen peroxide formed by oxidation with water. As mentioned, solvent is used for the wood. the hydrogenation produced hydroquinones at least two higher, secondary aliphatic alcohols. Examples of secondary aliphatic alcohols which may be used in accordance with the invention are alcohols having 7-9 carbon atoms. In particular, mention should be made of 2-octanol and 2,6-dimethyl-4-heptanol.

Ved at variere det indbyrdes volumenforhold mellem sådanne alkoholer med hver for sig forskellig fordelingskoefficient kan arbejdsopløs- 4 146651 ningens fordelingskoefficient indstilles på en med hensyn til hydro-genperoxidindholdet i den oxiderede arbejdsopløsning passende størrelse, uden at andelen af hovedsageligt anthraquinon- og tetrahydro-anthraquinonopløsende opløsningsmiddel behøver at ændres.By varying the volume ratio of such alcohols to different distribution coefficients individually, the distribution coefficient of the working solution can be adjusted to a size appropriate to the hydrogen peroxide content of the oxidized working solution, without the proportion of mainly anthraquinone and tetrahydro-anthraquinone solution. needs to be changed.

En høj fordelingskoefficient er fordelagtig med hensyn til ekstraktionsprocessen. Den kan enten benyttes for at spare materiale og energi i processen eller for at tilvejebringe en høj hydrogenper-oxidkoncentration i vandekstrakten. Det sidste indebærer også materialebesparelse hvad angår lagerlokaler og energibesparelse ved transport samt ved en eventuelt efterfølgende koncentreringsproces. Som tidligere nævnt kan imidlertid en alt for høj fordelingskoefficient indebære risici. Ved industrielle processer kan fordelingskoefficienten variere mellem f.eks. 30 og 50, og en passende værdi kan f. eks. være 45. En arbejdsopløsning ifølge opfindelsen kan til tilvejebringelse af denne fordelingskoefficient indeholde f.eks.A high coefficient of distribution is advantageous in terms of the extraction process. It can either be used to save material and energy in the process or to provide a high hydrogen peroxide concentration in the water extract. The latter also involves material savings in terms of storage space and energy savings during transport as well as in any subsequent concentration process. However, as previously mentioned, an excessively high coefficient of distribution may involve risks. In industrial processes, the coefficient of distribution may vary between e.g. 30 and 50, and a suitable value may be, for example, 45. A working solution according to the invention may contain, for example, this distribution coefficient.

46-54% aromatisk carbonhydrid 15-32% af et første opløsningsmiddel, som udgøres af en sekundær alkohol 39-14% af et andet opløsningsmiddel, som udgøres af en anden sekundær alkohol.46-54% aromatic hydrocarbon 15-32% of a first solvent constituted by a secondary alcohol 39-14% of a second solvent constituted by a second secondary alcohol.

Til de opløsningsmidler, som anvendes i anthraquinonprocessen, stilles flere fordringer, hvoraf fordringen om en passende fordelingskoefficient er vigtig, men ikke alene afgørende. Ved hydrogenerings-og oxidationsprocessen dannes der af anthraquinonerne relativt let biprodukter. Af tilstedeværende tetrahydroanthraquinoner dannes epoxi-der, der er helt uvirksomme som reaktionsbærere for hydrogenperoxid-processen. Der kendes ganske vist fremgangsmåder til gendannelse af virksomme tetrahydroanthraquinoner ud fra epoxiderne, men sådanne fremgangsmåder medfører øget forbrug af hjælpemidler og energi.For the solvents used in the anthraquinone process, several claims are made, of which the requirement for an appropriate coefficient of distribution is important, but not essential. In the hydrogenation and oxidation process, the anthraquinones form relatively easy by-products. Of tetrahydroanthraquinones present, epoxides are formed which are completely inactive as reaction carriers for the hydrogen peroxide process. Although methods for recovering effective tetrahydroanthraquinones from the epoxides are known, such methods result in increased consumption of aids and energy.

En arbejdsopløsnings opløsningsmiddeldel ifølge opfindelsen kan f.eks. bestå af 52% aromatiske carbonhydrider 30% 2-octanol 18 % 2,6-dimethy1-4-heptanol.The solvent portion of a working solution according to the invention may e.g. consist of 52% aromatic hydrocarbons 30% 2-octanol 18% 2,6-dimethyl-4-heptanol.

Dens fordelingskoefficient er 45. Dersom den oxiderede arbejdsopløsning indeholder 12 gram hydrogenperoxid pr. liter, kan vandekstrakten højest indeholde 540 gram hydrogenperoxid pr. liter , hvilket er acceptabeltud fra et sikkerhedssynspunkt og fordelagtigt med hensyn til materiale- og energiforbruget.Its partition coefficient is 45. If the oxidized working solution contains 12 grams of hydrogen peroxide per minute. per liter, the water extract may contain no more than 540 grams of hydrogen peroxide per liter. per liter, which is acceptable from a safety point of view and advantageous in terms of material and energy consumption.

146651 5146651 5

EksempelExample

En arbejdsopløsning indeholdende 105 gram tetrahydroanthraqui-noner og opløsningsmidlerne aromatiske carbonhydrider, 2-octanol og 2,6-dimethyl-4-heptanol i volumenforholdet ca. 5:2:3 anvendes i 2100 timer i en kontinuerlig proces til fremstilling af hydrogenperoxid. Som katalysator ved hydrogeneringen anvendes finkornet Raney-nikkel.A working solution containing 105 grams of tetrahydroanthraquinones and the solvents aromatic hydrocarbons, 2-octanol and 2,6-dimethyl-4-heptanol in a volume ratio of approx. 5: 2: 3 is used for 2100 hours in a continuous process for the production of hydrogen peroxide. As the catalyst in the hydrogenation, fine-grained Raney nickel is used.

I det nævnte tidsrum hydrogeneredes, oxideredes og ekstraheredes hver del af arbejdsopløsningen ca. 600 gange. I hele forsøgsperioden blev der ikke foretaget nogen speciel regenerering af epoxider, og man fjernede heller ikke på anden måde sådanne ikke ønskelige oxidationsprodukter fra arbejdsopløsningen. Ved driftsperiodens afslutning konstateredes, at arbejdsopløsningen indeholdt 2 gram epoxider pr. liter, hvilket er et overraskende lavt indhold. I tysk fremlæggelsesskrift nr. 1.273.499 omtales epoxidindhold, der går op til 17-50 gram pr. liter.During the said period, each part of the working solution was hydrogenated, oxidized and extracted for approx. 600 times. Throughout the experimental period, no special regeneration of epoxides was performed, nor were such undesirable oxidation products removed from the working solution. At the end of the operating period, it was found that the working solution contained 2 grams of epoxides per day. liter, which is a surprisingly low content. German Patent Specification No. 1,273,499 mentions epoxide content which goes up to 17-50 grams per minute. liter.