Characterization and Performance Analysis of Various Biomass Feedstocks in a Downdraft Gasifier

Gasification has gained recognition as an effective waste-to-energy (WTE) conversion method due to its low tar production, superior producer gas yield, and enhanced efficiency compared to other thermochemical routes like pyrolysis, incineration, and combustion of waste materials. Utilizing gasification for power generation using biomass as an alternative to traditional fossil fuels is expected to significantly address the pressing challenges associated with coal, petroleum, and similar fuels. The study deals with the performance assessment of a downdraft gasifier (10 kWth) utilizing binary mixtures of blends of sawdust (SD) and cow dung (CD) at different weight ratios, as feedstock. Gasification performance was assessed concerning the producer gas yield, lower heating values (LHV), and gasification efficiencies. Experiments were conducted at 800 °C at an equivalence ratio (ER) = 0.3. The H2 content in the producer gas is practically identical for individual and blended biomasses. However, increasing the amount of cow dung content in the cow dung/sawdust blend causes a modest drop in CO and CH4 levels and increases the CO2 concentration in the producer gas. The highest LHV was found for the producer gas obtained from individual sawdust feedstock, measuring 6.972 MJ/Nm3. The cold gas and carbon conversion efficiencies decrease with increasing cow dung content in the binary mixture. The maximum values are found for sawdust briquettes measuring 65.52% and 95.08%, respectively.