Examinando por Autor "Morselli, L."

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Feedstock recycling of agriculture plastic film wastes by catalytic cracking
(ELSEVIER, 2004) Serrano, D.P.; Aguado, José; Escola, J. M.; Garagorri, E.; Rodríguez, J. M.; Morselli, L.; Palazzi, G.; Orsi, R.
Feedstock recycling by catalytic cracking of a real plastic film waste from Almeria greenhouses (Spain) towards valuable hydrocarbon mixtures has been studied over several acid catalysts. The plastic film waste was mostly made up of ambient degraded low-density polyethylene (LDPE) and ethylene-vinyl acetate copolymer (EVA), the vinyl acetate content being around 4 wt %. Nanocrystalline HZSM-5 zeolite (crystal size ¿ 60 nm) was the only catalyst capable of degrading completely the refuse at 420ºC despite using a very small amount of catalyst (plastic / catalyst mass ratio of 50). However, mesoporous catalysts (Al-SBA-15 and Al-MCM-41), unlike it occurred with virgin LDPE, showed fairly close conversions to that of thermal cracking. Nanocrystalline HZSM-5 zeolite led to 60 wt % selectivity towards C1 - C5 hydrocarbons, mostly valuable C3 - C5 olefins, what would improve the profitability of a future industrial recycling process. The remarkable performance of nanocrystalline HZSM-5 zeolite was ascribed to its high content of strong external acid sites due to its nanometer dimension, which are very active for the cracking of bulky macromolecules. Hence, nanocrystalline HZSM-5 can be regarded as a promising catalyst for a feasible feedstock recycling process by catalytic cracking.
Thermal and catalytic cracking of a LDPE-EVA copolymer mixture
(ELSEVIER, 2003) Serrano, D. P.; Aguado, José; Escola, J. M.; Rodríguez, J. M.; Morselli, L.; Orsi, R.
Catalytic cracking of a plastic mixture consisting of LDPE and EVA copolymer (86/14 w/w) over mesoporous Al-SBA-15 and Al-MCM-41 materials as well as nanocrystalline HZSM-5 zeolite (crystal size ¿ 35 nm) has been carried out in a batch reactor at 400 - 420ºC. The release of acetic acid formed from the EVA decomposition was observed within the temperature range 350 - 400ºC. The most active catalyst was nanometer size HZSM-5 that led to complete conversion of the plastic mixture at 420ºC whereas both Al-MCM-41 and Al-SBA-15 were meaningfully less active. In addition, the polymer mixture was more difficult to be cracked both thermally and catalytically than pure LDPE. This result has been ascribed to the occurrence of crosslinking reactions leading to a fast deactivation by coke fouling especially over mesoporous catalysts (Al-MCM-41 and Al-SBA-15) because of their open structure. A high selectivity towards C1 - C5 hydrocarbons (¿ 75 %) was attained over nanometer size HZSM-5, most of them being valuable C3 - C4 olefins. PIONA analyses of the C6 - C12 hydrocarbon fraction obtained at 420ºC indicates that olefins were the main components whereas a significant amount of aromatics was also obtained both thermally and catalytically (> 15 %).