Thermo-catalytic studies on a mixture of plastic waste and biomass

Abstract

The effects of various catalysts on the composition of volatile pyrolysis products of a plastic waste and biomass mixture (1:1) were studied, by pyrolyzing the mixture sample using slow and fast heating rate. Various zeolite catalysts (β-and Y-zeolites, ZSM-5 and FCC) and nickel-molybdenum catalyst on alumina support were applied to find suitable catalysts for upgrading the quality of the thermal decomposition products of the waste mixture. A sample to catalyst ratio of 2:1 was used in the experiments. The rate of evolution of the decomposition products under slow pyrolysis was measured by thermogravimetry/mass spectrometry (TG/MS). The composition of the pyrolyzates was analyzed in detail by pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS) method. The influence of all applied catalysts was more pronounced on the plastic content of the sample than on biomass. The pyrolysis experiments revealed that the catalysts promoted the cracking reactions of the evolved hydrocarbons; furthermore, the formation of aromatic products was enhanced remarkably in the presence of all zeolite catalysts. Beta-zeolite and ZSM-5 catalysts were found the most effective in cracking hydrocarbons to gaseous products and in aromatization, while the highest CO2 formation was obtained by FCC from the biomass part of the studied waste mixture. NiMo catalyst promoted the H2 production from the plastic part; furthermore, slight aromatization and cracking effects were also observed.

Insights into in-situ catalytic degradation of plastic wastes over zeolite-based catalyst from perspective of three-dimensional pore structure evolution

“…The matrix with acidity builds up an interconnected network of micro-, meso-and macropores for heavy compounds accessing into internal surface and precracking. Considering the structural similarity of polyolefins-derived tar and crude oil, it is of great prospect to utilize FCC catalyst to transform petroleum-based plastic wastes into aromatics, olefins and paraffins in a scale-up application [12][13][14][15]. Andreas et al [16] employed steam-treated FCC catalysts for in-line catalytic upgrading of polyolefin and found the FCC catalyst obtained higher yields of C 5 -C 11 aliphatics up to 42 wt%, that is more active than the HZSM-5-containing additives in converting C 12+ products.…”

Insights into In-Situ Catalytic Degradation of Plastic Wastes Over Zeolite-Based Catalyst from Perspective of Three-Dimensional Pore Structure Evolution

“…The matrix with acidity builds up an interconnected network of micro-, meso-and macropores for heavy compounds accessing into internal surface and precracking. Considering the structural similarity of polyolefins-derived tar and crude oil, it is of great prospect to utilize FCC catalyst to transform petroleum-based plastic wastes into aromatics, olefins and paraffins in a scale-up application [12][13][14][15]. Andreas et al [16] employed steam-treated FCC catalysts for in-line catalytic upgrading of polyolefin and found the FCC catalyst obtained higher yields of C 5 -C 11 aliphatics up to 42 wt%, that is more active than the HZSM-5-containing additives in converting C 12+ products.…”