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Two processes of utilizing polyvinyl chloride (PVC) waste, an incineration process and a vacuum pyrolysis process, for energy conversion were compared to determine their efficiency and environmental performance. We carried out a life cycle assessment with each of the two processes to evaluate their environmental impact and defined the goals and limits of our remit. As well, we established an inventory of PVC waste from incineration and vacuum pyrolysis based on process analysis, data collection and calculations. The results show that electrical power output per unit mass of PVC waste in the incineration process was twice as high as that of the vacuum pyrolysis process. Incineration had a larger total environmental impact potential than vacuum pyrolysis. The total environmental impact potential of PVC waste from incineration was three times higher than that from vacuum pyrolysis. Incineration of PVC disposed 300 ng·100 kg of dioxins and vacuum pyrolysis 98.19 ng·100 kg of dioxins. As well, we analyzed the data for their uncertainty with results quantified in terms of three uncertainties: basic uncertainty, additional uncertainty, and computational uncertainty. The coefficients of variation of the data were less than 25% and the quality of the inventory data was acceptable with low uncertainty. Both PVC waste disposal processes were of similar quality and their results comparable. The results of our life cycle impact assessment (LCIA) showed considerable reliability of our methodology. Overall, the vacuum pyrolysis process has a number advantages and greater potential for development of PVC disposal than the incineration process. [ABSTRACT FROM AUTHOR]

A solvent extraction process is proposed to recover uranium and thorium from the crystal waste solutions of zirconium oxychloride. The extraction of iron from hydrochloride medium with P350, the extraction of uranium from hydrochloride with N235, and the extraction of thorium from the mixture solutions of nitric acid and the hydrochloric acid with P350 was investigated. The optimum extraction conditions were evaluated with synthetic solutions by studying the parameters of extractant concentration and acidity. The optimum separation conditions for Fe (III) are recognized as 30% P350 and 4.5 to 6.0 M HCl. The optimum extraction conditions for U (VI) are recognized as 25% N235 and 4.5 to 6.0 M HCl. And the optimum extraction conditions for Th (VI) are recognized as 30% P350 and 2.5 to 3.5 M HNO in the mixture solutions. The recovery of uranium and thorium from the crystal waste solutions of zirconium oxychloride was investigated also. The results indicate that the recoveries of uranium and thorium are 92 and 86%, respectively. [ABSTRACT FROM AUTHOR]

A series of catalysts LaCeCoO, LaCeCoPtO and Pt/LaCeCoO were prepared by combustion method and impregnation method, respectively. The purpose of the present work was to study the effect of platinum, with the same loading, on the platinum-substituted perovskite and perovskite-supported platinum catalyst. The catalysts structure were characterized by X-ray diffraction (XRD), BET measurements, transmission electron micrographs (TEM) and the methane oxidation activity of the catalysts were investigated in detail. It was found that the catalytic activity of LaCeCoPtO was superior to that of LaCeCoO and the activity performance of Pt/LaCeCoO was higher than that of LaCeCoPtO for methane combustion. [ABSTRACT FROM AUTHOR]