Catalytic pyrolysis of PVC and biomass using K2CO3 for HCl adsorption and upgrade of the bio-oil

Abstract

The effect of K₂CO₃ on the fast co-pyrolysis of poly(vinyl chloride) (PVC) and wood powder (WP) was studied. The pyrolysis characteristics were studied using TGA and the pyrolysis experiments were carried out on a fixed bed reactor. The results showed that after the addition of K₂CO₃, the solid residues increased, and the weight loss of the sample decreased. The activation energy and the pre-exponential factor were determined by kinetic methods, and the addition of WP was found to decrease the activation energy of the first and second stages of the PVC pyrolysis. When K₂CO₃ was added, the first stage activation energy of the mixture increased and the second stage activation energy decreased. The analysis of the solid product showed that K₂CO₃ could effectively absorb the HCl produced by pyrolysis. The results of fixed-bed experiments showed that K₂CO₃ could inhibit the generation of polycyclic aromatic hydrocarbons (PAHs) and promoted the generation of monocyclic aromatic hydrocarbons, which could be attributed to the catalytic action of alkali metals and the enhancement of the pyrolysis behavior by CO₂ release.