An animal farm operator is considering the addition of an anaerobic digestion

facility to its operations. The biogas produced from this facility is expected to

significantly reduce its green house gas emissions by reducing its natural gas

consumption.

Please address the following:

Part a

Using a block flow diagram of the process show the following main steps.

$1.$ Anaerobic digester

$2.$ Biogas storage and combustion

$3.$ Sludge dewatering stage

$4.$ Disposal of waste sludge $(20)$

Part b

What will be net reduction in CO$2$ emissions from the new facility in kg$/$day$,$

assuming all the biogas produced is used in its operations. $(20)$

Following addional information is given:

$1.$ Biogas production rate: $120$ m$3/$day

$2.$ Biogas composition: $60\%$ methane & $40\%$ CO$2$