Biomass is likely to be a significant energy resource in the future. A common way to recover energy from biomass is through gasification where synthesis gas is produced; by-products of this process are tar and ash/char. This research investigates the potential to use the ash/char as a catalyst by understanding the properties of char generated under different gasification conditions. Specifically, it is desired to produce a porous char which could be used as a catalyst or as a support for more catalytically active metals. In this work, poplar wood was gasified under CO2, steam, and air at different reaction temperatures. Experiments were done in a fluidized bed reactor at temperatures of 500°C, 750°C and 920°C and char was recovered. BET-surface area measurements showed that gasification under CO2 has the potential to produce char with a higher surface area than char produced from steam gasification. Higher temperature or longer gasification times resulted in the production of a more porous char. TGA experiments showed that gasification under CO2 resulted in a higher mass loss compared to gasification with steam. Gasification with steam/CO2 mixtures yielded a mass loss similar to that of steam only which could be indicative of competitive reactions between steam and CO2. Experiments done in an ESEM allowed for visual observation of the changes in physical properties of the biomass during gasification. With CO2, physical changes were observed at temperatures as low as 400°C whereas physical changes were not observed under steam at this temperature.

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