Study of the pyrolysis of polyester/viscose fibers catalyzed by tungsten-manganese bimetal supported montmorillonite

Abstract

The upgrading of pyrolysis deoxygenation of polyester/viscose fibers was examined in this paper utilizing montmorillonite (MMT) catalysts with varying ratios and amounts of tungsten-manganese bimetallic. The temperature-programmed desorption of NH₃ (NH₃-TPD) revealed that after tungsten-manganese bimetal loading, MMT formed novel acidic sites, resulting in a considerable rise in total acidity. The maximum aromatics yield (73.10%) was achieved by the MMT with a bimetal loading of 10 wt%, the yield of monocyclic aromatic hydrocarbons (MAHs) was highest at 40.38%, while the yield of polycyclic aromatic hydrocarbons (PAHs) was lowest. The MAHs yield dramatically dropped at 15 wt% and 20 wt% bimetal loading. The application of a moderate load has the potential to facilitate the generation of MAHs, whilst an excessive load can readily facilitate the development of PAHs. The acid equilibrium of MMT was enhanced following the application of varying ratios of tungsten-manganese bimetal loading. When the ratio of bimetal load was 1:1, a significant synergistic impact was seen, resulting in a substantial enhancement of the catalyst regulation performance on MAHs and PAHs. Specifically, the catalyst exhibited a tendency to generate a higher proportion of useful MAHs (40.38%) while simultaneously reducing the production of PAHs (32.72%). This phenomenon can be attributed to the appropriate pore structure and the equitable distribution of Lewis acid and Brønsted acid sites within the pores.