TG/FT-IR analysis of HZSM5 and HUSY deactivation during the catalytic pyrolysis of polyethylene

Evolution of products during the degradation of polyethylene in a batch reactor

“…Bockhorn et al [11] also found a higher yield of paraffins in the isothermal pyrolysis of polyethylene (not specified whether LDPE or HDPE), but they observed that at low temperatures (430 8C), the ratio of paraffins to olefins was constant over time, while at higher temperatures (480 8C) the mole fraction of paraffins increased with time while that of olefins decreased. Marcilla et al [12] reported no change in the relative intensity of the IR bands obtained from the products evolved in dynamic TG/FTIR experiments during the thermal pyrolysis of polyethylene.…”

Catalytic pyrolysis of high density polyethylene in a conical spouted bed reactor

“…Moreover, it improves the yield of volatile products and provides selectivity in the product distribution, especially for obtaining products of great commercial interest (gasoline and monomers) [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. The more used catalysts are acid ones (zeolites HY, HZSM-5, Hb, MCM-41) and they activate the well-known carbocationic mechanisms for cracking the primary product molecules (mainly waxes) and the subsequent reactions of isomerization, oligomerization-cracking and hydrogen transfer.…”

IR spectroscopic analysis of the structure of a biospecific sorbent based on a polyethylene matrix

“…: there are bands at 2917 cm -1 and 2839 cm -1 due to antisymmetric and symmetric stretching vibrations of the CH 2 groups, and bands at 2948 and 2866 cm -1 associated with the asymmetric and symmetric stretching vibrations of the CH 3 groups [14,15]. The bands in the 1470-1430 cm -1 region observed in the IR absorption and MATR spectra are due to bending vibrations of both the CH 2 and CH 3 groups of the polyethylene [14,15].…”

“…The bands in the 1470-1430 cm -1 region observed in the IR absorption and MATR spectra are due to bending vibrations of both the CH 2 and CH 3 groups of the polyethylene [14,15]. The presence of a rather intense band at 1373 cm -1 suggests significant numbers of CH 3 groups in the structure of the studied polyethylene [14].…”

“…Figure 1 shows the IR absorption spectra for samples of the original polyethylene (PE) and the PE-PAA. We know that in the IR spectrum of polyethylene, there are a series of absorption bands in the intervals 3100-2600 and 1500-700 cm -1 , due to stretching and bending vibrations of the CH 2 group respectively [14,15]. In technical-grade polyethylene, along with CH 2 groups there are CH 3 groups, the vibrations of which appear in the same regions [14].…”