Co-pyrolysis of waste tire and pine bark for syngas and char production

Abstract

Thermochemical conversion of waste tire blended with forestry waste (waste blends) into syngas can help support energy security, provide solutions for the management of rapidly growing waste tires, climate change and environmental degradation. In this paper, co-pyrolysis of waste tire and pine bark mixtures was examined under N2 atmosphere at 900 °C using a lab-scale fixed-bed reactor test facility. The focus was on the evolutionary behavior of different components in the syngas (flow rates of CO, H2, CmHn hydrocarbons), total syngas yield, overall energy efficiency and solid residues characteristics. Insight into the effect of different blend fractions of in several discrete ratios of waste tire (W) and pine bark (P), termed as (W:P) = 0:100, 25:75, 50:50, 75:25, and 100:0 was also obtained. Synergistic effects on the syngas and solid yield under the defined blend ratios of waste tire and pine bark were reported. Results showed that peak flowrate of H2, CO, total syngas increased with increase in pine bark in the mixture, but the peak flow rate of CmHn decreased. H2, CmHn, total syngas, solid residues yield and overall energy efficiency showed synergistic interaction to varied extent. With increase of pine bark in blends, mole fraction of CmHn decreased while CO increased. BET surface area characterization of the solid residue indicated there was an interaction on the surface of waste tire and pine bark during co-pyrolysis supported by SEM of the char residue. These results help provide some practical insights on clean energy recovery from mixtures of waste tire and forestry wastes using thermochemical conversion.