Abstract: Systems and methods are provided for the treatment of caustic wastewater. Specifically, systems and methods are provided for combining refinery spent caustic and ethylene spent caustic solutions and treating the combined spent caustic mixture using a wet air oxidation process.

Abstract: Systems and methods are provided for the treatment of caustic wastewater. Specifically, systems and methods are provided for combining refinery spent caustic and ethylene spent caustic solutions and treating the combined spent caustic mixture using a wet air oxidation process.

Abstract: Systems and methods are provided for the treatment of caustic wastewater. Specifically, systems and methods are provided for combining refinery spent caustic and ethylene spent caustic solutions and treating the combined spent caustic mixture using a wet air oxidation process.

Abstract: A wet oxidation process is used to control the concentration of reduced sulfur compounds from a viscose process. The wet oxidation process oxidizes the reduced sulfur compounds to convert such reduced sulfur compounds to an alkali sulfate and/or thiosulfate species. The alkali sulfate stream is recycled to the viscose process. Oxidation is performed under elevated temperature and pressure conditions such that the offgas has an oxygen concentration of between about 2% to 18% and the alkali sulfate stream has a pH of about 2 to 10.

Abstract: Systems and methods are provided for the treatment of caustic wastewater. Specifically, systems and methods are provided for combining refinery spent caustic and ethylene spent caustic solutions and treating the combined spent caustic mixture using a wet air oxidation process.

Abstract: A process is disclosed for producing an oxidized liquid effluent containing minimal dissolved gases therein, from a subcritical wet oxidation treatment system. The oxidation mixture exiting from the treatment system is separated into a first oxidized liquid effluent and a first gaseous phase as the mixture a first separator vessel operated at a relatively low superatmospheric pressure. Sufficient pressure is maintained in the first gaseous phase to provide the motive force for transport to further treatment or discharge. The first oxidized liquid effluent flows to a second separator vessel operated at essentially atmospheric pressure, where remaining dissolved gases separate from the first oxidized liquid effluent. The second gaseous phase is discharged and the second oxidized liquid effluent is suitable for storage or further treatment. Provision for adjusting the pH of the oxidized liquid effluent during the separation process is also disclosed.

Abstract: Disclosed is a process for wet oxidation treatment of high strength liquor or wastewater to destroy a substantial portion of the pollutants and produce an effluent stream containing a high solids content for recovery or disposal. The liquor is treated by wet oxidation and separate vapor and liquid streams are removed from the wet oxidation reactor. The vapor stream is cooled and separated to give a liquid condensate phase and a gaseous phase. The liquid stream from the reactor is cooled and divided, with a portion of the liquid effluent sent to recovery or disposal, and a portion combined with the condensate phase. This low pollutant content stream is used to dilute the raw feed liquor and maintain a high solids concentration in the liquid effluent stream.

Abstract: This invention relates to a process and apparatus for dissipating the energy of a wet oxidation mixture after that stream traverses a pressure control valve. The depressurized stream is discharged into a phase separator vessel containing a gas phase and a liquid phase. The pressure control valve is positioned to discharge the oxidation mixture at a selected orientation below the surface level of the liquid phase in the vessel. This dissipates the energy of the mixture and prevents erosion of the phase separator vessel. The apparatus of the invention includes the separator vessel with gas and liquid phase exits, a control device for maintaining the liquid phase at the selected level in the vessel, a pressure control valve positioned at an aperture in the vessel for discharging the mixture below the surface level of the liquid phase in the vessel, and sealing device between the control valve and the separator vessel.

Abstract: This is a process for wet oxidation of an ammonium salt containing waste liquor which prevents plugging of the vapor-carrying lines of the wet oxidation system. The vapor-carrying lines are maintained in an unobstructed condition by adding sufficient liquid water to dissolve condensed ammonium salt which can plug these lines. This provides for safe operation of the wet oxidation system.

Abstract: A two-stage wet oxidation process for COD removal from high strength wastewater is disclosed. The wastewater stream is treated in a first stage subcritical wet oxidation zone at temperatures between about 250.degree. and 374.degree. C. to remove a substantial portion of the COD. Subsequently, all or a portion of the first stage oxidized waste stream is treated in a second stage supercritical wet oxidation zone at temperatures of 374.degree. to about 600.degree. C. to remove any remaining COD content. Both stages of wet oxidation treatment are carried out at essentially the same system pressure.

Abstract: The invention is a process for starting up a wet oxidation system using essentially pure oxygen for oxidation of a concentrated wastewater. Flow of startup water and air is established through the wet oxidation system at an elevated temperature and pressure. An incremental increase in flow of oxygen and wastewater to the system commences while simultaneously an incremental decrease in flow of startup water and air occurs, raising system temperature in a controlled fashion. The incremental changes in flows are repeated until the wastewater and pure oxygen have reached about 100 percent of selected operating flows, the startup water and air flows have decreased to zero, and the system has attained the selected operating temperature, while maintaining a selected oxygen residual in the offgases.

Abstract: A process is disclosed which limits the corrosion of the materials of construction of a wet oxidation system treating wastewaters. The process is particularly useful in the wet oxidation treatment of ammonium sulfate containing wastes such as acrylonitrile wastewaters. The wastewater is mixed with an oxygen containing gas such that a substantial residual oxygen gas concentration is maintained from before the stream-gas mixture is heated for wet oxidation until after the oxidized stream-gas mixture is cooled and separated. Preferably, in the treatment of acrylonitrile waste water the shutdown procedure comprises cooling said waste stream by introducing an aqueous liquid substantially free of organic impurities and containing a basic material.

Abstract: A process for treating an aqueous wastewater containing ammonium compounds. The process comprises the steps of preheating a liquid influent and introducing the preheated influent, an oxygen-containing gas an the wastewater into a reaction vessel for undergoing wet oxidation. An oxidized effluent is then withdrawn from the reaction vessel, which includes a gas phase containing ammonia and carbon dioxide and a liquid phase containing the ammonium compounds. The temperature of the effluent is then reduced to a temperature sufficient to condense a substantial portion of the ammonia into the liquid phase, and afterwards the remaining gas phase containing a substantial portion of the carbon dioxide is separated from the resulting liquid phase.

Abstract: An apparatus for injecting a mixture of pure oxygen or oxygen-enriched air (at least 25 percent oxygen) and purge water into a wet oxidation reactor operating at elevated temperature and pressure. An annular space between the oxygen carrying pipe and a second, larger pipe is filled with heat transfer resisting material, either maintained static or passed through the annular space to remove heat therefrom. The temperature of the oxygen and purge water is maintained at less than 250.degree. F., preferably less than 150.degree. F. to minimize evaporation of the purge water. Thus, backflow of organic matter into the oxygen pipe is prevented; plugging of the oxygen pipe by salts is also prevented.

Abstract: A method comprising operating steps required for safely operating wet oxidation reactors in which combustible substances are oxidized at elevated temperatures and pressures using pure oxygen. The steps satisfy the criteria that a potential of oxidation is established prior to introducing oxygen and maintained until after oxygen flow is stopped; that an inert gas, either from an external source or generated in situ, is present in the reactor from before oxygen flow is introduced until after oxygen flow is stopped; and that the oxygen introducing means is clean for oxygen use from prior to the introduction of oxygen flow until after the oxygen flow is stopped.