Synthesis and characterization of TPA loaded mesoporous catalysts and their performance in pyrolysis of polypropylene

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Kimya Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2013

Öğrenci: CEREN KASAPOĞLU

Danışman: NAİME ASLI SEZGİ

Özet:

Plastic materials have attracted attention in recent years because of their functionalities therefore; they are widely used in household and industry. As their usage increases, plastic waste amount also increases and this is an important environmental problem. Chemical recycling of these materials is a useful method to solve this problem because plastic materials can be converted into petrochemical feedstock with this method. In this study, tungstophosphoric acid (TPA) loaded SBA-15 materials were synthesized hydrothermally to be used in degradation of polypropylene. TPA was incorporated to the porous framework of SBA-15 with different W/Si ratios. The synthesized catalysts characterized using XRD, Nitrogen Physisorption technique, SEM and FTIR and their performances were tested in TGA. XRD analysis revealed that introducing TPA did not cause deformations in the regularity and the catalysts showed an amorphous structure. N2 adsorption-desorption isotherms showed that the synthesized materials exhibited type IV isotherms. The surface areas of the samples were in the range of 478-786 m2/g depending on the amount of TPA loaded. Pore size distributions showed their mesoporosity. The average pore sizes were approximately 7.0 nm. SEM images indicated the hexagonal structure. DRIFTS spectra showed that TPA loading resulted in the formation of Brønsted acid sites and as the amount of TPA increased, the peak intensity of the Brønsted acidity increased. TG analysis revealed that when catalyst amount used in the experiments and TPA amount loaded into the materials increased, the degradation temperature decreased. Activation energy values of the samples were between 92.5 and 165.8 kJ/mole depending on the TPA loading amount and they are lower than that of pure polypropylene degradation reaction.