Real-time performance assessment of open-top downdraft biomass gasifier system

Biomass gasification is a promising technology for electricity generation, thermal application, and synthesis of chemicals. Present investigation was carried out to obtain temperature profile, evolutionary characteristics of producer gas composition, calorific value at the different flow rate, and morphological characteristics of eucalypts and their residue. Result show that producer gas so obtained has a reasonably high calorific value of 3.709 MJ/Nm(3), with carbon monoxide (13.3%) and hydrogen (10.8%). The lowest CH4 and CO2 values are 0.9 and 9.2% at the moisture content of 8.5% and equivalence ratio of 0.309 (optimal equivalence ratio for the best performance of the downdraft gasifier). Morphological analysis showed the transformation of all volatiles give way to pores and tube-like structures, seen in the eucalyptus residue indicating enhanced porosity. The absence of an aliphatic C-H peak (3000-2500 cm(-1)) in the residue indicates that the aliphatic structure was disturbed during the thermochemical conversion. The crystallinity of the residue decreases as it degrades throughout the gasification process. The TG-DTG analysis gives information of thermochemical properties of biomasses before gasification.