Optimizing waste valorization: catalytic co-pyrolysis of cabbage waste and tire waste for enhanced bio-oil and syngas production utilizing char as a reforming catalyst

Abstract

This study explores the catalytic co-pyrolysis of cabbage waste (CW) and tire waste (TW) to enhance the yield and quality of bio-oil and syngas. Although CW is produced in large quantities from global cabbage cultivation, its lower hydrogen content limits its utility for fuel and chemical production. The co-pyrolysis process, utilizing char as a catalyst, presents a cost-effective approach to optimize product outputs by promoting the reforming of volatiles during thermal decomposition. Thermogravimetric-infrared spectrometry (TG-FTIR) and a dual-stage fixed bed reactor were employed to assess thermal behavior, the release of evolved gases and product composition. Results demonstrated that catalyst-assisted co-pyrolysis with char reduced non-condensable emissions to 33.45% and increased condensable products to 66.57%, compared to 39.57% and 60.46% for co-pyrolysis alone, and 49.23% and 50.77% for CW pyrolysis. Furthermore, char-mediated volatile reforming significantly decreased the oxygenated fraction to 6.7% from 13.6% in co-pyrolysis and 22.5% in CW pyrolysis and greatly increased phenolic compounds and aromatics to 28.3% and 31.7% from 22.3% and 27.8% for co-pyrolysis, 17.9% and 21.7% for biomass pyrolysis, respectively. This research highlights the potential of integrating biomass and waste materials to promote sustainable energy solutions through enhanced resource utilization and diminished environmental impact.