high temperature airsteam gasification of steam exploded….pdf

1 Energy-and Furnace Technology HIGH TEMPERATURE AIR/STEAM GASIFICATION OF STEAM EXPLODED BIOMASS DuleekaSandamaliGunarathne Jan Karol Chmielewski(PhD) WeihongYang (PhD) ******@ Tel: +4687908402 Royal Institute of Technology (KTH) School of Industrial Engineering and Management Department of Materials and Science Engineering Division of Energy and Furnace Technology Stockholm, Sweden 2 Energy-and Furnace Technology Presentation schedule ?Introduction to biomass pretreatment ?Opening possibilities ?Background ?Objective of present work ?Methodology: The system and the fuel ?Gasification performance ?Insight into behaviour of tar ?Conclusions 3 Energy-and Furnace Technology Biomass pretreatment ?Mechanicalpretreatment ?Torrefaction ?HTC ?Steamexplosion –heating biomass under high pressure steam –sudden release of pressure assuring explosive pression –Typical conditions: ?Pressure: - MPa ?Temperature: 170-250 oC ?Time: 10sec-10min –limited energy consumption –low use of chemicals 4 Energy-and Furnace Technology Opening possibilities Structural change Effect Ultimate result Opening possibilities Hemicellulose & cellulose de- polymerization Low thermal stability 1-5 Early thermal degradation + Low temperature operations possible Altered lignin structure Release of minerals Low alkali metal content and low ash content High ash fusion temperature + High temperature operations possible Less reactive - Need longer bed (high H/D ratio) Release of hemicellulose to solution Low hemicellulose content Reduced volatiles Less hydroxyl groups 3 Hydrophobic + Transportation and storage easiness Less amorphous structures (High crystallinity) 6 Heat diffusion limitations 7 - High temperature operation suitable Reduced O content Low O/C and H/C (moving close to peat region) + Co-gasification possible High lignin content High C content High heating value High energy density + Positive in transportation and storage Disintegration of biomass Fine part