Thermal and catalytic pyrolysis of polyethylene over HZSM5 and HUSY zeolites in a batch reactor under dynamic conditions

Literature survey for a first choice of a fuel-oxidiser couple for hybrid propulsion based on kinetic justifications

“…The gaseous part increases with the temperature up to about 90 wt.% at 1053 K. The oil is composed of aromatics. For both LDPE and HDPE, the proportion between paraffin (alkanes), olefin (alkenes) and aromatics are the same in the liquid or gaseous phases during pyrolysis [50]. The atmosphere also impacts on HDPE pyrolysis and it can yield low polycyclic aromatic hydrocarbons (PAH)…”

Thermal and catalytic pyrolysis of plastic waste

“…These intermediate radicals can be submitted to break the carbon-carbon bond by scission β to produce compounds saturated or with unsaturated terminal and new radicals. The transfer of intra / intermolecular hydrogen depend on the experimental conditions, the first of which leads to an increase in the production of olefins and diolefins, paraffins results in the second [34,36,37] . The termination reactions can occur, for example, by disproportionation, which can produce different olefins and alkanes or a combination of radicals can lead to the same products.…”

“…The mechanism involves the stages of initiation, propagation and / or free radical transfer followed by β chain scission and termination [20,34,36] . This mechanism provides many oligomers by hydrogen transfer from the tertiary carbon atom along the polymer chain to the radical site [18] .…”

“…The products obtained from the pyrolysis can be divided into non-condensable gas fraction, liquid fraction (consisting of paraffins, olefins, naphthenes and aromatics) and solid waste. From the liquid fraction can be recovered hydrocarbons in the gasoline range (C4-C12), diesel (C12-C23), kerosene (C10-C18) and motor oil (C23-C40) [1,3,18,20,[33][34][35] .…”

Co-Production of Liquid and Gaseous Fuels from Polyethylene and Polystyrene in a Continuous Sequential Pyrolysis and Catalytic Reforming System

“…In addition, during the aromatization reaction, a considerable number of hydrogen atoms are abstracted which subsequently accumulate on the catalyst surface, and then consumed in the hydrogenation of olefins. Moreover, the HY-zeolite adsorbed polar molecules strongly, which may also lead to a possible explanation for the increase of iso-paraffins at the expense of olefins (Marcilla, Beltran & Navarro, 2009 ;Manos & Garforth, 2000). Therefore, a lot of aromatics and iso-paraffins at the expense of the n-paraffins and olefins existed in the final liquid products.…”