The Effect of Torrefaction Pre-Treatment on the Gasification of Biomass

thermochemical conversion of biomass to produce clean and quality heat, power and liquid fuels from biomass (Bhagavatula 2014).It could facilitate the use of biomass for co-firing in large coal-fired plant, distributed power generation using diesel AbstractRaw biomass has enormous potential as a feedstock for gasification, but its inherent characteristics limit its wide scale use.Properties such as high moisture content, high O/C ratio, low bulk density, heterogeneous nature, and lower grindability make its handling and gasification difficult.Furthermore, higher tar formation during the gasification of raw biomass increases the downstream cost of gas separation.Pre-treatment of biomass through torrefaction could remove some of these limitations, making biomass more suitable for gasification.Experiments in both batch and continuous modes of steam-gasification show that torrefaction pre-treatment decreases the tar by 79% and increases the quality of product gas.However, reactivity and the gas yield are found to be lower for torrefied biomass than raw biomass.The effect of torrefaction and gasification temperature on the product composition showed H2/CO ratio 1.5, 1.7 and 1.9 for raw, torrefied biomass at 250 o C and 275 o C respectively.Scanning Electron Microscope (SEM) analysis showed less fibrous characteristics of torrefied biomass.Brunauer-Emmett-Teller (BET) analysis of raw and torrefied biomass shows higher surface area for torrefied biomass char as compared to raw biomass char after devolatilization.The results are discussed in the paper.