A comprehensive study on upgradation of pyrolysis products through co-feeding of waste tire into rice straw under broad range of co-feed ratios in a bench-scale fixed bed reactor

Abstract

A comprehensive study investigating all co-pyrolysis products (bio-oil, char, and gas) utilizing bench-scale reactor is essential for potential use in upscaling and techno-economic analysis for commercialization and integration of pyrolysis with conventional systems. This study explores the co-pyrolysis of rice straw (RS) and waste tire (WT) to assess the impact on products under a broad range of feedstock ratio (20, 40, 60, and 80 wt% of WT into RS) in fixed bed reactor at 550 °C. Results revealed that feedstock mass ratio played a crucial role to transform the oxygenates into hydrocarbons (HCs). Liquid yield, organic phase, pH, aromatics, and olefins increased with increase of WT proportion in blend. Bio-oil yield, aromatics and olefins reached to 45 wt%, 42%, and 30% at WT/RS (80:20) compared to 36 wt%, 2%, and 4% in the case of RS alone, respectively. Likewise, at the same blend ratio, 85% reduction in oxygenates was observed while higher heating value (HHV) of bio-oil (41.40 MJ/kg) was comparable to that of WT (41.50 MJ/kg). Significant positive synergy was achieved for non-condensable gas after incorporation of WT into RS. Hydrogen (H2) and methane (CH4) along with higher HCs were increased while oxides of carbon reduced with the addition of WT compared to RS alone. Char characteristics also improved with addition of WT into RS in terms of increased carbon content, HHV, and reduced ash content.