Answer the following.
(a) Which fuels can be obtained by microbial processes? Why is it necessary to increase the use of such fuels?

Explanation

The fuels which can be obtained by microbial processes are:
1. Gaseous fuel: Methane can be obtained by microbial anaerobic decomposition of urban agriculture dn industrial waste.
2. Ethanol (alcohol) is a clean (smokeless) fuel obtained during fermentation of molasses by the yeast- Saccharomyces.
3. Hydrogen gas is considered to be fuel of future. Hydrogen gas is released during bio-photolysis of water in which bacteria perform the photo reduction.
4. It is necessary to increase the use of microbial fuel because, of the following reason:
a.They are clean and eco-friendly.
b.The energy production is from renewable resource such as waste water, urban agriculture and industiral waste and from organic waste.
c. These fuels are inexhaustible.