2.1.2. Biochar preparation
A lab-scale slow pyrolyzer was used for biochar production. The pyrolysis system (Figure
1) consists of a 4-liter volume batch reactor equipped with a programmable temperature
controller (up to 1200 o
C), a cooling system to collect bio-oil, and a source of nitrogen to
modify the pyrolysis atmosphere. The batch reactor was filled with feedstock, covered with
a fitting lid, and pyrolyzed under oxygen-limiting conditions. Vapors generated during the
process were condensed to collect bio-oil. After pyrolysis, biochar in the reactor was
allowed to cool overnight to room temperature. The weights of the bio-oil and biochar
collected were measured to obtain pyrolysis yields. The yield of each bio-product was
4
defined as the ratio of the weight of the product to that of the original feedstock. Syngas
yield was obtained through mass balance. The produced biochars were sealed in an airtight
container and stored at room temperature until use