The contents of biogas were measured using a GC (Varian Inc.)
equipped with a thermal conductivity detector (TCD) and
a FID. An 180 1/80 (inside diameter) Silcosteel column packed
with HayeSep Q (80e100 mesh) was used to separate CO2 and
CH4. TCD and FID detector temperatures were maintained at
150 and 225 C, respectively. Nitrogen was used as the carrier
gas at a flow rate of 30 mL/min