Recovery and Reduction of Spent Metal Catalyst via Plasma Sintering Technique

• Main Authors: Kuo-ChenChiang, 江國振
• Other Authors: Yun-HweiH Shen
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/46192475608883941499

博士 === 國立成功大學 === 資源工程學系碩博士班 === 98 === Plasma is a quasi-neutral gas consisting of a large amount of charged and neutral active species. These diverse active species with the high energy radiation capability of plasma can help to enhance the chemical reactions substantially and to make some reactions possible. As for gasification, it is commonly applied to convert coal, biomass, and waste materials to syngas and useful chemicals in industries. Supported metallic catalysts were widely used in industry for hydrogenation, hydrotreating, and steam-reforming reaction. The metallic catalysts was supported on the ceramic substrates (i.e., silica and alumina) to increase its surface area for achieving better catalytic efficiency. After multiple of catalytic reactions, the surface of metal-supported catalyst was completely covered with organic tar and loses its catalytic efficiency. This thesis is the recovery of metal and reduction of metal oxide of the spent catalyst in nitrogen medium under plasma conditions. The spent catalysts were sintered and organic wastes are converted to syngas in thermal plasma reactor. The gases evolved upon recovery of metal (Pt) and reduction of metal oxide (NiO2, Co3O4-MoO2) to metal are continuously pumped out the system and clarify the spent alumina-supported platinum catalyst. The results demonstrate that the thermal plasma treatment makes reduction of metal oxide to metal by single step thermal plasma processing. Key word： Oxidation catalyst；Alkali metal transition elements；Support carrier material；Plasma sinter；syngas；catalyst reduction