Design of bench–scale auger pyrolysis reactor: Experimental investigation on rice husk biomass

Abstract

India has biomass potential of 500 million metric tons per year in the form of agricultural residue. Pyrolysis is one of the extensively studied thermal decomposition for conversion of biomass into various high calorific value products. In this study attempt to address the problem of alternative energy sources and utilizing the biomass potential of India is made. This study examines the influence of temperature (450–600 °C) on pyrolysis product yields (bio-oil, biochar, and gases) in a newly designed and fabricated twin-screw auger reactor. A key innovation of this reactor is its integrated provision for catalytic upgrading, facilitated by an attached fixed-bed reactor, enhancing its capability for in-situ bio-oil improvement — a novel feature compared to existing systems. Results indicate that bio-oil yield increases from 27% to 33% as temperature rises from 450 °C to 550 °C, peaking before declining at 600 °C due to secondary cracking. Biochar yield decreases (42% to 36%) with increasing temperature, while gas yield rises, dominated by CO (34.11% to 40.8%) and declining CO₂ (42.18% to 23.7%). Methane and hydrogen production also increase at higher temperatures, driven by cracking and dehydrogenation reactions. These findings, consistent with prior studies, highlight the reactor’s potential for optimized pyrolysis and catalytic upgrading, offering a significant advancement in biomass conversion technology.