A spent caustic treatment process addresses the shortcomings with traditional Wet Air Oxidation Systems. The process can treat either refinery or sulphidic spent caustic streams with CODs of up to 50,000 mg/L. The process uses >90% oxygen as an oxidising agent. A horizontal, tubular reactor is operated at pressures between 100 and 170 Bar (ideally 145-165 Bar). The reactor has an operating temperature of between 120° C. and 320° C., ideally 280° C. to 300° C. A closed heat transfer medium circulation loop is utilised for heat recovery from the reactor effluent stream to the spent caustic feed stream. The invention allows for a COD reduction of 75 to 99.9%.
A process performed by a plant for oxidation of a waste stream with oxidizable material is described. In a start-up phase, supercritical water is fed to a supercritical water oxidation reactor, heating the process up to supercritical conditions. In a treatment phase, the waste stream is fed to the reactor for supercritical water oxidation treatment, in which sufficient mass of water under supercritical conditions is present in the reactor to retain supercritical conditions with the newly introduced waste stream. Oxygen is used as oxidant and a stoichiometric quantum is added to the reactor. The energy released from the oxidation reaction substitutes the energy provided by the addition of supercritical water up to a point where the reactor achieves near autothermal conditions with supercritical water providing trim heat requirement. The reactor outlet is quench cooled, neutralised and energy is recovered from it. A gas liquid separator ensures that the effluent stream is degassed.
Supercritical gasification of a waste stream uses a supercritical finned tubular reactor (R-1301) with optional oxidant injection at a plurality of injection points, the injection rates being chosen according to the nature of the stream material and downstream process control parameters. After the reactor there is heat recovery from the effluent stream, subsequent cooling (C-1101) followed by pressure reduction (X-1401) to provide a first reduced-pressure stream which is separated (S- 1501) into gas and liquid components. Hydrogen peroxide is injected into the liquid stream ensuring near complete oxidation of residual COD still contained within the treated liquid effluent stream. The liquid component is cooled (C-1402) and there is a further pressure reduction (X- 1402) to provide a reduced-pressure liquid stream. There is then separation (S-1502) of the reduced-pressure liquid component to provide a further gas component and liquid component. Gas components from the first gas and liquid separation step (S-1501) are distributed based on the requirement of the process or downstream processes.
B01J 3/00 - Procédés utilisant une pression supérieure ou inférieure à la pression atmosphérique pour obtenir des modifications chimiques ou physiques de la matièreAppareils à cet effet
A process performed by a plant for oxidation of a waste stream with oxidizable material is described. In a start-up phase, supercritical water is fed to a supercritical water oxidation reactor (TK-001), heating the process up to supercritical conditions. In a treatment phase, the waste stream is fed to the reactor for supercritical water oxidation treatment, in which sufficient mass of water under supercritical conditions is present in the reactor to retain supercritical conditions with the newly introduced waste stream. Oxygen is used as oxidant and a stoichiometric quantum is added to the reactor. The energy released from the oxidation reaction substitutes the energy provided by the addition of supercritical water up to a point where the reactor achieves near autothermal conditions with supercritical water providing trim heat requirement. The reactor outlet is quench cooled, neutralised and energy is recovered from it. A gas liquid separator ensures that the effluent stream is degassed.
224 4 waste stream from an alumina refining process. This achieves destruction of the oxalate and a feedback of filtrate to the digestion stage (4) of the refining process. The feed stream is pumped under high pressure through a tubular reactor (27) in which there is pre-heating and in-reactor heating to bring the stream up to a temperature in the range of 290ºC to 330ºC. The pumps provide a pressure in the range of 90Bar to 160 Bar, and a retention time in the range of 8 minutes to 30 minutes. Downstream of the reactor there is separation (32) of the treated liquid to provide a gas and a liquid containing sodium carbonate, treatment (33) of the gas to provide a safe discharge to the atmosphere, and treatment (40) of the separated liquid to provide a treated stream.
C01F 7/47 - Purification de l'oxyde d'aluminium, de l'hydroxyde d'aluminium ou des aluminates des aluminates, p. ex. l'élimination des composés de Si, Fe, Ga ou des composés organiques des liqueurs issues du procédé Bayer
A spent caustic (SC) treatment process addresses the shortcomings with traditional Wet Air Oxidation (WAO) Systems. The process can treat either refinery or sulphidic spent caustic streams with CODs of up to 50,000 mg/L. The process uses >90% oxygen as an oxidising agent. A horizontal, tubular reactor is operated at pressures between 100 and 170 Bar (ideally 145 – 165 Bar). The reactor has an operating temperature of between 120°C and 320°C, ideally 280°C to 300°C. A closed heat transfer medium circulation loop is utilised for heat recovery from the reactor effluent stream to the spent caustic feed stream. The invention allows for a COD reduction of 75 to 99.9 %.
B01J 3/00 - Procédés utilisant une pression supérieure ou inférieure à la pression atmosphérique pour obtenir des modifications chimiques ou physiques de la matièreAppareils à cet effet
Hydrothermal apparatus and installations for use in the treatment and disposal of sludges from sewage and wet waste, for the recovery of residual material by-product, and for use in power generation; waste water purification apparatus, installations, and tanks; purification installations for sewage and wet waste
39 - Services de transport, emballage et entreposage; organisation de voyages
40 - Traitement de matériaux; recyclage, purification de l'air et traitement de l'eau
Produits et services
Industrial waste purification plants; waste water treatment apparatus and installations, apparatus for water supply and sanitary purposes; installations and apparatus for waste water engineering; water purification installations; apparatus and instruments for the treatment of waste water, waste sewage and recovery from materials from waste. Distribution of waste. Treatment of materials; services for the recovery of materials from waste; energy generation; destruction of organic wastes; treatment of waste; processing and chemical treatment of waste materials.
