Experimental investigation on gasification of cationic ion exchange resin used in nuclear power plants by supercritical water

Spent ion exchange resins produced by nuclear power plants are radioactive organic waste. Until now, there is no satisfactory industrial treatment. Supercritical water gasification (SCWG) of cationic ion exchange resin (CIER) used in nuclear power plants was carried out in a batch reactor in this study. Results showed that the gasification efficiency increased with the growth of temperature (550-750 degrees C), addition of alkali homogeneous catalyst (K2CO3), proper ratio loading of catalyst to CIER (1:1), decrease of feed concentration (2-10 wt%) and extension of residence time (10-60 min). Carbon gasification efficiency was up to 97.98% with K2CO3 added and 30 min at 750 degrees C in the batch reactor. The gaseous products mainly consist of H2, CO, CO2 and CH4. The GC-MS analysis showed that the organic component in liquid products was mainly composed of benzene, monocycle arenes, phenol group and polycyclic aromatic hydrocarbons. Based on the experimental results, the formation and gasification pathways of CIER in SCW were proposed.

Automated summary

Supercritical water gasification can effectively treat the radioactive organic waste produced by nuclear power plants. By adjusting parameters such as temperature, catalyst addition, and residence time, the gasification efficiency can be improved, with the main gas products being H2, CO, CO2, and CH4, and the organic components mainly including benzene, aromatic hydrocarbons, and polycyclic aromatic hydrocarbons.