| 초록 |
Plastic wastes, which cause a serious environmental problem in urban areas, can serve as sources of energy. For chemical recycling of waste plastics, clinoptilolite zeolites and halloysite were examined as catalysts for the degradation of polypropylene in a semi-batch reactor system, and their activities was studied. The proton form of the natural clinoptilolite zeolite(H-NZ), halloysite(HH), montmorillonite(HK30) and pyrophyllite were modified by treatment with NH4Cl. The degradation was carried out with a mixture of polypropylene and catalyst in the range of 350-450℃. The liquid products, formed in the catalytic degradation of polypropylene with clinoptilolite zeolites, montmorillonites and halloysites, are distributed in a narrow range of carbon numbers compared with those obtained by thermal degradation. Modified catalysts showed an improved catalytic performance of the degradation and was found to be very effective for the production of gasoline-range fuel oils. The natural halloysite catalyst was an efficient catalyst for the polypropylene degradation. The acidity and characteristic pore structure of halloysite and clinoptilolite zeolite appear to be responsible for the good performance. The effects of temperature, contact time, and the reaction time on the product distribution in polypropylene degradation are also discussed in this work. |
