Patent GB-706686-A (GB)
Title: Process for the destructive oxidation of organic materials in aqueous media
Inventor: ZIMMERMANN FREDERICK JOHN
IPC: C02F11/08
Filed: 1950-06-15
Abstract: Destructive oxidation of organic materials in an aqueous medium comprises the steps of continuously feeding to a reaction zone the aqueous medium containing the organic material and an oxidizing gas such as air in quantity at least sufficient to oxidize the whole of the organic materials, maintaining in the reaction zone a temperature above 450 DEG F. and a pressure sufficient to maintain the water in liquid form so as to cause the organic material to be oxidized, the reaction being initiated by the application of heat to the reaction zone, and the requisite temperature in the reaction zone being thereafter maintained by heat from the exothermic oxidation proceeding therein.  Since the reaction is exothermic, the organic materials may thus be used as fuels for the generation of heat or power.  Suitable materials are liquors resulting from paper and pulp mill operations such as sulphite liquor, sewage waste, waste effluents from slaughter-houses, plastic-, rubber-, dye- and pharmaceutical factories and the like, milk process waste liquids and low-grade powdered coals mixed with a relatively large quantity of water. Where the organic materials in the aqueous medium are insufficient to maintain a self sustaining destructive oxidation, other organic materials such as oil sludge, comminuted organic refuse, coal dust, or the like may be added.ALSO:Destructive oxidation of organic materials in an aqueous medium comprises the steps of continuously feeding to a reaction zone the aqueous medium containing the organic material and an oxidizing gas in quantity at least sufficient to oxidize the whole of the organic materials maintaining in the reaction zone a temperature above 450 DEG  F. and a pressure sufficient to maintain the water in liquid form so as to cause the organic material to be oxidized, the reaction being initiated by the application of heat to the reaction zone, and the requisite temperature in the reaction zone being thereafter maintained by heat from the exothermic oxidation proceeding therein. The reaction products from the reaction zone may be passed to a gas-liquid separator in which the pressure is reduced, the separated gaseous product being passed to an expansion engine (such as a turbine) whilst heat is recovered from the liquid products.  In an example the apparatus consists of a pump for the aqueous dispersion, an air compressor, an oil-jacketed tower reactor provided with means for periodically removing precipitate, and a flash chamber to receive the reaction product from the reactor.  Air at 1,500 pounds per square inch is admitted to the reaction system, the oil bath around the reactor is heated to about 536 DEG  F. and the reactor two thirds filled with waste sulphite liquor.  Lime sufficient to convert the sulphur in the liquor to calcium sulphate had been added.  When the liquor in the reactor reaches a temperature of about 518 DEG  F. sufficient liquor is pumped into the reaction system to fill it with liquid.  Heating of the oil is discontinued and air is continuously supplied to the reactor at the above pressure, at a temperature of 86 DEG  F. and at a rate of 400 lbs. per hour (92.6 lbs. oxygen per hour).  Waste liquor at 65 DEG  F. is pumped under a pressure of 1,500 lbs. per square inch and at a rate of 7.8 gallons per hour. Precipitated calcium sulphate is periodically removed from the reactor and liquor leaving the reactor is passed into the flash chamber from which nitrogen, carbon dioxide and any excess air are bled off with steam at a pressure of 1,500 lbs. per square inch; the quantity of steam amounts to 2.2 lbs. per gallon of liquor fed. Liquid effluent from the flash chamber amounts to 5.8 lbs. per gallon of liquor fed to the reactor and is at a temperature of 540 DEG  F. Examples of other starting materials are: Liquors resulting from paper and pulp mill operations, sewage waste, waste effluents from slaughterhouses, plastic-, rubber-, dye- and pharmaceutical factories and the like, milk-process waste liquids, and low-grade powdered coals mixed with a relatively large quantity of water. Where the organic materials in the aqueous medium are insufficient to maintain a self-sustaining destructive oxidation, p  other organic materials such as oil sludge, comminuted organic refuse, coal dust, or the like may be added.