Question

(a) List two ways in which animal dung can be utilized as fuel.

(b) Out of these two which one is better?

(c) Justify your answer.

Answer 1

(a)

There are two ways in which animal dung can be used as fuel:

1. To heat animal dung in the form of cakes after drying them.
2. Anaerobic degradation of animal dung to produce useful fuel called biogas.

(b)

1. Biogas is more efficient since it has a high calorific value.

(c)

1. Biogas has thermal efficiency higher than that of cow dung.
2. Because it doesn't contain moisture while cow dung has a lot.