Hydrocracking of Heavy Hydrocarbons in a Plasma Spouted-Bed Reactor: Role of Alkyl Aromatic Compounds in the Presence of a High Flow of Hydrogen Radicals

The aim of this work is the petroleum residue reforming. For this purpose, a plasma spouted-bed reactor has been selected. In order to promote cracking reactions and to avoid coke formation, a high flow of hydrogen radicals, obtained from an inductively coupled argon-hydrogen plasma, is introduced into the reactor. The weak activation energy E_a of the n-C₁₆H₃₄ cracking in the presence of atomic hydrogen (96 kJ/mol) compared to classical cracking energy value (250 kJ/mol) confirms the catalytic role of adsorbed atomic hydrogen.
In the plasma spouted-bed reactor, the high flow of hydrogen radicals promotes the toluene Ø−C bond scission, leading to a methyl radicals enrichment. Thus, an increase of the methyl radical flux raises the cracking rate by a factor of two, by increasing the preexponential term of the kinetic constant. Both H° and CH₃° radicals seem to control the conversion rate of hydrocarbons, the kinetics phenomena and the carbon black deposit through recombinaison reactions with macro-radicals which are responsible for deposits.