Perpustakaan Digital ITB

Global energy demand continues to rise, necessitating a transition from fossil fuels to sustainable biomass energy sources. Raw biomass such as rice husk and sawdust exhibits high moisture and low energy density, limiting their direct application. This research aims to analyze the thermochemical performance of a lab-scale autothermal dual-stage continuous entrainedflow biomass carbonizer, addressing the operational limitations of previous designs by implementing a shortened reactor length and upgraded feeding system. The research specifically investigates the effects of equivalence ratio (ER) and feeding configurations on biochar production and quality. The experimental methodology involved systematic variations of the ER and feeding configurations for both sawdust and rice husk. The carbonizer was operated at a shorter length to study the impact of reduced residence time and improved feeding capacity on mass flow stability. Performance was assessed through solid yield quantification, proximate and ultimate analyses, particle size distribution, and Higher Heating Value (HHV) measurements. This approach allows for a comprehensive comparison between the two biomass feedstocks under controlled autothermal conditions. Results demonstrate that feedstock characteristics significantly dictate conversion performance. Rice husk, stabilized by its silica-ash matrix, achieved superior mass retention, with the dualstage configuration significantly increasing the solid yield rate to 2.837 kg/h by bypassing pneumatic choking limits. Conversely, sawdust, being highly volatile, exhibited lower mass yield but superior energy densification, reaching an Enhancement Factor of 1.60. The dualstage configuration for sawdust increased mass recovery but suffered from incomplete devolatilization and tar-induced slagging at low ERs. Ultimately, this study establishes that while rice husk is optimal for bulk production, sawdust is preferred for deep carbonization applications, contributing essential data for upscaling continuous carbonization technology in industrial co-firing.