Environmentally Friendly Waste System

We met Dr Han to finalise the details of the digester. We have the drawings of the final design at the bottom:

(photos to be added all at once)

There are a few differences in design of the prototype in comparison to the actual digester. Firstly, there is the addition of stirrers at both stages to homogenize the sludge. Also, the prototype design consists of a thermostat to control the temperature in the aerobic stage which makes it more convenient. Then we also incorporated the methane capture section of the design. A vacuum pump is needed to ensure there is a pressure difference and hence allowing the biogas to be transferred to the methane capture device for separation. Another minor difference is the incorporation of gas test sockets and pressure gauges to allow easier reading.

In the methane capture device, the biogas is passed through an activated carbon filter before being bubbled into water or an organic solvent (NaOH) this would ensure that the carbon dioxide and the hydrogen sulphide is removed from the biogas and pure methane can be trapped. In the design, there is a pipe leading out from the solvent containment to allow for drainage.

He also introduced us to the project supervisor, Ireaneus. He is to guide us through the whole building of the prototype and handle all the technical issues.