(63p) Influence of Temperature, Gas Flow Rate, and Steam/Biomass Ratio On Gasification of Algae Biomass

Biomass gasification is one of the most promising avenues in the field of alternative fuels. It is being looked at both as a method for production of syngas which will be used in catalytic reforming processes such as Fischer-Tropsch, and as a source of pure H₂ for fuel cell applications, just to name a few. The objective of this research was to determine the effects of temperature, gas flow rate, and steam/biomass ratio on the conversion of algae biomass to syngas during steam gasification. The temperature range used in these experiments was 1000°C -1300°C which exceeds the range of 400°C-900°C that is used in most gasification research. The motivation for exceeding the traditional gasification temperature range was to obtain gasification data that can be used to predict gasification results in solarthermal reactors which can easily achieve temperatures in excess of 1000°C. The algae gasification results were also compared with switchgrass gasification data that was obtained using the same experimental methods to determine which might be a better choice for syngas production. The data yielded the results that conversion and H₂ concentration have a strong dependence on increasing temperature. It was also shown that steam to biomass ratio increases and carrier gas flow rate decreases conversion, but both have more negligible effects than temperature. Algae and switchgrass had maximum conversions of 66% and 95% respectively at 1300°C. It was also found that temperature increases the selectivity of H₂ and decreases CO selectivity. The surprising result was that switchgrass had much higher conversions under the same operating conditions even though it contains lignin. Research is currently in progress to explain this result.