The digestion was a batch process and 6 kg each of pre-fermented
Lemon grass, Cow dung and Poultry droppings was respectively
mixed with water to form slurry in the ratio 1:1 by volume
and introduced into Reactor A, B and C respectively through an inlet
pipe of 50 mm at the top of each reactor. The slurry was allowed
to occupy three quarter of the digester space leaving a clear height
of about 0.0625 m as space for the gas production. Before feeding
the reactors, the flexible hose connecting the gas outlet from the
reactor to the gas holder was disconnected, such that the gas outlets
from the reactors were left open. This was done to prevent
negative pressure build up in the reactors. The gas was collected
from the digesters through a 10 mm diameter flexible hose connected
from the digesters to the bottom of the gas collection systems.
The collected gas was allowed to pass through water and
slaked lime respectively as scrubbers.