ChemChar gasification of radioactive, inorganic, and organic laden wastes

The ChemChar gasification process is a cocurrent flow gasification process that utilizes a unique triple reverse burn (TRB) char to mix with liquid and sludge wastes to produce a readily handled product. The process has been shown to effectively treat a wide variety of wastes to produce combustible gas products while largely retaining metals and inorganics on the char matrix. The process has also been shown to be effective in destroying any organic constituents present in a waste without producing SOx or NOx gases nor chlorinated dibenzodioxins or chlorinated dibenzofurans, all of which can occur with other thermal treatment methods such as incineration.; A laboratory scale ChemChar gasification process was utilized to investigate the fate of various radionuclides during gasification, study the destruction and subsequent phosphorous distribution from chemical warfare surrogates, and explore the destruction of chlorofluorocarbons and retention of chloride and fluorine. A larger scale 4-inch diameter gasification system was also evaluated in this study.; It was found that the radioisotopes arsenic, uranium, thorium, neptunium and protactinium were essentially all retained in the laboratory scale gasifier column with a small amount of the As, Th, Pa, U and Np being found in downstream components and none of the radiotracers exiting the gasification system. For mercury, much greater volatilization was observed, none of the mercury escaped the gasification system however. Using this methodology, the fate of arsenic, cesium, and strontium during gasification in the presence of organic matter was determined. It was found that similar behavior was seen with the As, Cs, and Sr being found almost exclusively in the reactor column with minute amounts being found downstream and none exiting the gasification system.; The ChemChar process was also found to be particularly effective in treating chemical warfare surrogates and chlorofluorocarbons (CFCs). Destruction removal efficiencies (DREs) of greater than 99.9996% were found for the treatment of chemical warfare surrogates such as parathion while DREs of greater than 99.9998% were found for the treatment of the CFC 1,1,2-trichloro-1,2,2-trifluoroedme. Additionally, the phosphorus that results from the destruction of chemical warfare surrogates was found to be retained in the gasification system with the majority isolated in the reactor column. The halides that result from the destruction of CFCs were found to exhibit similar retention.; Finally, a 4-inch diameter ChemChar gasification system was constructed and its operation evaluated by treating two surrogate waste mixes. It was found that DREs of greater than 99.99% were achieved for all of the organic constituents with no organics escaping the gasification system, while over 99% of the metals and radionuclide surrogates were found to be retained in the reactor column.; These studies illustrate that the ChemChar gasification process holds significant promise as an alternative to other thermal waste treatment processes such as incineration for the safe and complete destruction of hazardous wastes.