UNITED STATES - PRODUCTION and Recovery of HYDROGEN Peroxide Gerhard A
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Patented Oct. 21, 1952 ". UNITED STATES - PRODUCTION AND RECovERY of HYDROGEN PERoxIDE Gerhard A. Cook, Snyder, N.Y. signor, by mesne assignments, to Union Carbide and Car bon Corporation, a corporation of New York NoDrawing. Application May 27, 1948, serial No. 29,671 6 claims. (CI, 23-207) 2 It is known that hydrogen p produce hydrogen peroxide, made by oxidizing propane, ethane, he treatment as drocarbons under suitable peroxide-forming con proposed will substantially increase the final ditions, such, for example, as are shown in my yields of this product, and it will contribute recently issued Patent No. 2,416,156. Aldehydes, greatly to the commercial economy of such a such as formaldehyde and acetaldehyde, are also process. formed in such a reaction, and while these com: The following examples will be further illus pounds seem to have very little affinity toward trative of the invention: . hydrogen peroxide in the vapor ph - - - - - - - Eacample 1 '...'... ." ... *- : ' '... ::... presence in a condensed solution product is dif- 10 A solution typical of those to ..which this re covery process is applicable was made. up, by mixing commercial formalin with an aqueous a hydrogen peroxide solution, in proportions to provide one mole of formaldehyde for each mole of hydrogen peroxide, and diluting with water. Twenty milliliters of this... solution. (containing 0.03 mole of peroxide), was cooled to 0°C. and added rapidly, with vigorous mechanical stirring, to a lime slurry. The lime slurry had been pre viously cooled to 4°C., and was prepared by Suspending. 0.037. mole of... a pure commercial calcium hydroxide. in 80 ml. of water. After completing the mixture, the solution was stirred 5 for an additional 15 seconds, and was immedi method of recovering improved yields of hydro ately, filtered on a Buechner funnel...The filtra gen peroxide from solutions initially containing tion time required another 12, seconds, and the this compound in the presence of aldehydes filter cake was then immediately-washed clean which are readily reactable therewith. A further with water. Conversion...of peroxide in the object is to provide a practical metho con : starting. Solution to calcium peroxide reached wherebyverting organic improved peroxides efficiencies to hydrogen in production peroxide, of 30 a total of 96.8%, and upon drying at 609. C. for a the latter compound, as made byt period of 50 minutes, 2.5% of the -peroxide was tion of hydrocarbons, cé lost, presumably... by decomposition. The dried The invention com - 3: . product contained 81.6% CaO2. in which aqueous solutions containing the or- 35 . To...recover hydrogen-peroxide, the calcium ganic reaction products of aldehydes and hydro peroxide. So prepared was suspended in sufficient gen peroxide are first treated with hydroxides or water to give a slurry, containing 0.835. mole other compounds of metals which are capable of CaO2 per liter. While the slurry was vigorously forming peroxides insoluble in water, and the agitated at 25°. C., a rapid stream of CO2 was metal peroxides so formed are then treated with 40 passed through it for a period of three hours. acids to liberate hydrogen peroxide. Alkaline The solution was then filtered, and in the filtrate, earth metal compounds, in particular calcium 89.8% of the starting peroxide was recovered as and barium hydroxides, will react with organic H2O2, in a concentration of 2.5 grams per 100. peroxides to form insoluble metal peroxides, and ml...of solution. Unreacted CaO2 in the filter. after filtration and washing,' the latter.com. 45 cake amounted to , 4.0%, the balance apparently pounds can be made to release hydrogen peroxide being lost by decomposition. byRapid treatment precipitation, with carbonfiltration, dioxide and initial and water.wash ing of the insoluble metal peroxide are desirable, An aqueous solution obtained by scrubbing the to avoid further reactions which can readily occur 50 gases from a reactor operating under peroxide if formaldehyde is present in the solution, and it oxygenforming andconditions recycle ongases a mixture(propylene, of ethylene,propane, is further desirable to maintain temperatures carbon monoxide, etc.) was analyzed, and found preferably below about 20° C. during the precipi to contain 1.06 moles total peroxides, 0.41 mole tation treatment. As applied to the reaction total aldehydes (mostly formaldehyde and ac condensates from a hydrocarbon oxidation to." etaldehyde) and 0.30 mole total acid (mostly 2,614,907 4. formic and acetic acids) per liter. This Solu actable to organic peroxides, which comprises tion, in an amount of 1060 ml., was added to a adding calcium hydroxide to said Solution which slurry of 1.3 moles of Ca(OH)2 in 1300 ml. of converts all organic peroxides to calcium perOX water at 8° C. The addition took five minutes, ide, separating the calcium peroxide from the and clean ice was added to the reaction mixture Solution, and releasing hydrogen peroxide from to keep the temperature below 10° C. The pre Said calcium peroxide by treating an aqueous cipitate was then filtered off and washed three Suspension of the latter compound with carbon times, being dispersed each time in 800 ml. of dioxide. dilute clear lime water. After drying in air at 3. Process of recovering hydrogen peroxide 72° C. for a period of about 14 hours, 115 grams O from an aqueous solution initially containing said of dried product was obtained. This contained hydrogen peroxide and aldehydes readily re 61.5% by Weight CaO2, indicating a peroxide re actable to organic peroxides, which comprises covery from the initial solution of 89.2%. adding barium hydroxide to said solution which Hydrogen peroxide was then regenerated by converts all organic peroxides to bariumperoxide, suspending the dried calcium peroxide in water, Separating the bariumperoxide from the solution, and introducing carbon dioxide gas into the SuS and releasing hydrogen peroxide from said bari pension. The calcium carbonate formed Was ...um peroxide by treating an aqueous suspension filtered off, and the resulting solution was con- . of the latter compound with carbon dioxide. centrated by evaporation in vacuo until it con 4. In the production of hydrogen peroxide by tained 21 grams of H2O2 per 100 ml. of Solution. thermal oxidation of hydrocarbons, means for re Simple concentration by evaporation usually covering improved yields of hydrogen peroxide leaves a small amount of calcium carbonate in from the aqueous condensate solution of the re the solution, because of the slight solubility of action products containing organic peroxide, this compound in water, and for greater purity which comprises adding to said condensate solu in the product, the peroxide may be distilled off, tion an alkaline earth metal hydroxide which leaving all of the calcium carbonate behind. By precipitates the organic peroxides as correspond appropriate distillation, solutions having a con ing metal peroxide, separating the alkaline earth centration of over 90% peroxide have been ob metal peroxide from the solution, and releasing tained. hydrogen peroxide from said metal peroxide by Modifications over the exact procedure of the 30 treating with acid an aqueous suspension of the above examples, which will be apparent to those latter compound. skilled in the art, include the use of compounds 5. In the production of hydrogen peroxide by of metals other than calcium and barium to pre thermal oxidation of hydrocarbons, means for cipitate insoluble metal peroxide. Examples of recovering improved yields of hydrogen peroxide these are salts of uranium and thorium, which 35 from the aqueous condensate solution of the re will function as intended, although economical action products containing organic peroxides, ly such compounds may not be as practical as which comprises adding calcium hydroxide to the hydroxides of calcium and barium. Almost Said condensate solution which converts all or any inorganic acid soluble in Water can be used ganic peroxides to calcium peroxide, separating to liberate the hydrogen peroxide from the metal 40 the calcium peroxide from the solution, and re peroxide, but acids like carbonic (CO2) and Sul leasing hydrogen peroxide from said calcium furic are preferred, because they form insoluble peroxide by treating an aqueous suspension of salts with metals such as calcium and barium, the latter compound with carbon dioxide. thus permitting separation from the aqueous hy 6. In the production of hydrogen peroxide by drogen peroxide by simple filtration. Where the 45 thermal oxidation of hydrocarbons, means for re acid used may form a soluble salt, e.g. HCl, the covering improved yields of hydrogen peroxide hydrogen peroxide can usually be separated from from the aqueous condensate solution of the re the Salt component by distillation or extraction, action products containing organic peroxides, The proportions of the reactants do not appear Which comprises adding barium hydroxide to said critical, although a slight excess. Over Stoichio 50 condensate Solution which converts all organic metric amounts of the metal precipitant is peroxides to bariumperoxide, separating the bari usually desirable for more complete recovery. un peroxide from the solution, and releasing Large excesses should be avoided, as this may hydrogen peroxide from said barium peroxide by cause unnecessary contamination of the precipi treating an aqueous suspension of the latter com tated metal peroxide, and, at the same time, re 55 pound with carbon dioxide. quire too large amounts of acid to completely liberate the hydrogen peroxide. GERHARD A. COOK. I claim: . 1. Process of recovering hydrogen peroxide REFERENCES CITE) from an aqueous Solution initially containing Said 30 hydrogen peroxide and aldehydes readily reacta The following references are of record in the ble to organic peroxides, which comprises adding file of this patent: to said Solution an alkaline earth metal hydrox UNITED STATES PATENTS ide which precipitates the organic peroxides as Number. Nanne Date corresponding metal peroxide, separating the 65 1,235,664 Doerner ----------- Aug.