Study of the decomposition of low density polyethylene blends with vacuum gas oils: Evolution of the gases

Previous studies focused on the behaviour of different samples of vacuum gas oil (VGO), polyethylene (PE) and vacuum gas oil-polyethylene blends (VGO-PE) in thermal and catalytic pyrolysis, showed that the pyrolysis of the blends goes through two decomposition steps, where the first is related to the elimination of the VGO fraction, and the second to the pyrolysis of PE. Moreover, the presence of catalyst mainly affects the PE decomposition. In this work, the evolution of the composition of the gases evolved in the thermal and catalytic pyrolysis decomposition of VGO, PE and VGO-PE blend with temperature (or time) has been studied by GC/MS. The results agree with the previous studies and allow the behaviour of such systems to be better understood, yielding valuable information for designing processes of plastic recycling by mixing with VGO and the mixture being treated in a unit similar to the industrial fluid catalytic cracking unit.