Treatment of simulated waste TBP/n-dodecan and halogenated oils with steam reforming system

Steam reforming method has been developed for the treatment of organic wastes which are not suitable materials (tributyl phosphate, halogenated oil) for the incineration due to large quantities of secondary wastes generation. This method consists of the gasification process which includes the decomposition and vaporization of organic waste with superheated steam and the oxidation process which includes the oxidation and decomposition of vaporized waste with heated air. Process demonstration tests were conducted with the demonstration scale steam reforming system (maximum feed rate of waste: 3kg/h) to examine the feasibility of treatment of simulated waste solvent and simulated waste oils. These tests were also conducted to optimize the process conditions. In addition, the effluent gas from the system was analyzed to examine the possibility of explosion by the flammable gas generated in the system when the emergency shutdown was executed. TBP and n-dodecane mixture as simulated waste solvent and halogenated oils and mineral oil mixture as simulated waste oils were tested. The results of these studies are as follows: More than 98% of the simulated wastes were evaporated in the gasification process. Solid residues removed from the gasification process as secondary wastes were inorganic compounds. While the simulated waste oils were treated, the stacking of the filter is reduced by increasing the feed rate of steam from 1.5kg/h to 3.0kg/h. Most of phosphoric acids produced by thermal decomposition of TBP were vaporized in the gasification processes at 600-650degC. This result shows that volume of radioactive secondary waste can be effectively reduced. After the emergency shutdown of the system there is no possibility of gas explosion by remaining flammable gas. Because the concentration of oxygen in the gases became lower than minimum concentration of oxygen to support combustion of the gases by dilution with nitrogen gas fed into the gasification chamber. (author)