Optimization studies of waste plastics-lignite catalytic coliquefaction

Abstract

The optimization studies of an investigation for waste plastics-lignite catalytic coliquefaction are reported in this paper. At first, two SiO₂ supported, Pt-Co and Pt-Mo promoted bimetallic catalysts were prepared. Next, catalytic coliquefactions were attempted on 1/1 mixtures of lignite and waste polymers, e.g. polystyrene, polyisoprene and polyethylene in the presence of various organic solvents. Taking into consideration the results obtained from the variables examined, two newer series of experiments were designed and undertaken aiming at the optimization of this complex transformation. In the first series, the best performing catalyst and the selected most-effective waste plastics were employed and different mixtures of the two more active solvents were added. In the second series, coliquefactions of the precedent mixtures in two stages was attempted in order to optimize overall conversion so far attained. It was found that the mentioned catalytic coprocessing is an interesting form of hydrocarbon synthesis, although the efficacy of the conversion achieved was influenced by the chemical characteristics of the polymers added and of the solvents employed.