The Use of Combustion Process Modification to Capture Cesium from Combustion of Contaminated Biomass -- IT3
Citation:
Lemieux, P., S. Lee, W. Linak, AND L. Virtaranta. The Use of Combustion Process Modification to Capture Cesium from Combustion of Contaminated Biomass -- IT3. In Proceedings, 37th International Conference on Thermal Treatment Technologies (IT3) & Hazardous Waste Combustors Conference Proceedings, League City, TX, October 02 - 03, 2019. Air & Waste Management Association, Pittsburgh, PA, CP-233-EFS, (2019).
Impact/Purpose:
This paper reports on successful results to capture cesium from combustion of biomass using a kaolinite sorbent. This has the potential to be a technology of use to minimize radioactive waste from a radiological incident where massive quantities of biomass are contaminated.
Description:
In the aftermath of a wide-area radiological contamination incident in an urban setting, there is the potential for generation of significant quantities of contaminated biomass waste. These wastes are likely candidates for incineration as a means of volume reduction, due to the costs associated with disposal of large volumes of low-level radioactive waste. Radioactive Cesium (134Cs and 137Cs), an alkali metal element, might be used in a radiological dispersal device or may be the predominant long-term radionuclide contaminant from a nuclear power plant accident. Cs presents problematic behavior in combustion systems due to its volatility and solubility of many Cs species in water. Although high-temperature combustion or incineration systems cannot destroy the elemental metal constituents, these environments may induce metal transformations. These transformations may exacerbate difficulties in controlling the radionuclides of interest because many of the metal species, including Cs, vaporize readily within the combustion environments. This saturated vapor will subsequently nucleate and condense downstream of the flame, forming a fume of submicron aerosol with a mean volume aerodynamic diameter between 100 and 200 nanometers. These small particles are difficult to collect in pollution control systems such as electrostatic precipitators. The objective of this research was to: 1) Examine the behavior and transformations of biomass-bound Cs in an incinerator environment; and 2) Determine whether combustion modifications, including sorbent injection into the post-combustion zone of practical incinerators and combustors, could be used to convert biomass-bound Cs into easily collected forms. This paper reports on a series of tests performed in a pilot-scale rotary kiln.
