Performance of Acidic MCM-Like Aluminosilicate Catalysts in Pyrolysis of Polypropylene

Mesoporous aluminosilicate catalysts having different Al/Si ratios were synthesized following a hydrothermal synthesis route and using different aluminum sources, such as aluminum nitrate and aluminum isopropoxide. These mesoporous materials have high surface areas, in the range of 520-1001 m(2)/g, and exhibit Type IV nitrogen adsorption isotherms. EDS and Al-27 MAS NMR results showed that aluminum was incorporated more effectively into the structure of the catalyst forming a tetrahedral framework when aluminum nitrate was used as the aluminum source. The activities of these catalysts in the polypropylene pyrolysis reaction were tested in a TGA apparatus. Results showed a marked reduction in the degradation temperature in the presence of aluminosilicate catalysts. The activation energy of degradation was 172 kJ/mole without any catalyst. However, using the mesoporous aluminosilicate catalysts synthesized by using aluminum nitrate as the aluminum source, activation energy of the degradation reaction decreased to values of about 24-28 kJ/mole.


The synthesis and characterization of aluminum loaded SBA-type materials as catalyst for polypropylene degradation reaction
Obali, Zeynep; Sezgi, Naime Aslı; Doğu, Timur (2011-12-01)
The performance of pure and aluminum containing SBA-type catalysts prepared using different aluminum sources and different Al/Si ratios were investigated in the polypropylene degradation reaction using a thermogravimetric analyzer. For the synthesis of catalysts, aluminum isopropoxide and aluminum sulphate were used as the aluminum sources. Synthesized materials had high surface areas and exhibited nitrogen adsorption isotherms of type IV. EDS results showed that the aluminum incorporation into the structur...
Direct hydrothermal synthesis of palladium-incorporated silicate-structured mesoporous catalysts
Sener, Canan; Doğu, Timur; Dogu, Guelsen (2007-01-01)
Pd-Si-structured novel mesoporous nanocomposite catalytic materials, having quite high Pd/Si ratios, were synthesized by an acidic direct hydrothermal synthesis route. The nanocomposite catalytic materials were then characterized by XRD, XPS, EDS, nitrogen adsorption, and SEM techniques. Unlike MCM-41, the XRD patterns indicated a rather wide d((100)) band at a 2 theta value of about 1.9. The materials, with very high Pd/Si wt ratios between 1.43 and 2.66, were synthesized and had BJH surface area values be...
Performance of silicotungstic acid incorporated mesoporous catalyst in direct synthesis of dimethyl ether from syngas in the presence and absence of CO2
Çelik, Gökhan; Bayat, Aysegul; Ozbelge, H. Onder; Doğu, Timur (2013-12-01)
Dimethyl ether (DME), which is an excellent green diesel fuel alternate, is synthesized following a direct synthesis route from synthesis gas, by using a bi-functional catalyst mixture, which was composed of a silicotungstic acid incorporated mesoporous catalyst [TRC-75(L)] and a commercial Cu-Zn based catalyst. Higher DME selectivity values were obtained by using TRC-75(L), than commercial gamma-alumina at 50 bars. Presence of CO2 in the feed stream caused significant enhancement in DME selectivity. Result...
Catalytic degradation of polypropylene over alumina loaded mesoporous catalysts
Obali, Zeynep; Sezgi, Naime Aslı; Doğu, Timur (2012-10-01)
The catalytic thermal degradation of polypropylene over aluminum containing ordered mesoporous MCM-41 and SBA-15 based materials was studied in a semi-batch reactor. Heavier molecules degraded to lighter hydrocarbons in the presence of catalysts and they gave high ethylene selectivity among the gaseous products. Additionally, butane selectivity increased with the use of catalysts. SBA-type catalysts showed higher selectivity to lighter hydrocarbons (<C-14). C-7 selectivity among the liquid products was high...
Performance of TPA loaded sba-15 catalyst in polypropylene degradation reaction
Ersoy Yalçın, Ulviy; Tutumlu, Zeynep.; Department of Chemical Engineering (2019)
Plastic materials are widely used due to their low cost and easy processing properties. With an increase in plastic usage, the amount of plastic wastes has also increased, and this situation causes environmental problems. Landfilling, incineration, and recycling are the methods used for the disposal of plastic wastes. Landfilling is not a convenient method as it causes soil pollution. Incineration is also not preferred due to its harmful effects on the environment caused by toxic gases. Recycling seems to b...
Citation Formats
Z. Obali, N. A. Sezgi, and T. Doğu, “Performance of Acidic MCM-Like Aluminosilicate Catalysts in Pyrolysis of Polypropylene,” CHEMICAL ENGINEERING COMMUNICATIONS, pp. 116–130, 2009, Accessed: 00, 2020. [Online]. Available: