A mass spectrometer was used to measure the composition of
the product gases. The gas was first passed through a condenser to
remove tar and condensable vapors, and then passed a series of
filters to capture associated particles. Typically, tar produced by the
updraft gasifier is in the 100 g/Nm3 range. Detail experiments are in
progress to determine tar content as a function of ER and moisture
content with and without catalyst and the results will be reported
elsewhere. After steady state operation was achieved a small
amount of clean and cooled gas was supplied into the gas analyzer.
The gas analyzerwas pre-calibrated using a standard mixture of gas
(N2, CO, CO2, H2, C2H6, and CH4) and the inert gas (Helium) every
three days in order to improve its accuracy. The gas compositions
were recorded every 10 s when Tpeak fluctuationwas less than 10 C
by the gas analyzer when gasifier reached steady state.