Question

(a) Classify the two fuels – CNG and hydrogen – as renewable and non-renewable.
(b) Justify the statement. “Hydrogen is a cleaner and better fuel than CNG.”

Answer 1

Hint:Renewable energy (including fuels) comes from natural sources that are constantly replenished in the environment. Non-renewable energy comes from depleting sources such as fossil fuels. Fuel quality (cleaner and better) depends on the amount of by-products it leaves behind when it burns and how those products affect the environment.

Complete step by step answer:
(a) CNG stands for Compressed Natural Gas. It is a type of natural gas and is derived from the compression of fossil fuels. Hydrogen on the other hand can be made through a variety of domestic resources such as biomass, nuclear power and renewable power. Therefore, as CNG comes from fossil fuels, it takes thousands of years to get replenished and is a non-renewable fuel. Whereas, hydrogen is a renewable fuel source.

(b) CNG is derived from fossil fuels and thus, is a mixture of organic compounds. Thus, when it is burned, it creates hydrocarbon emissions. These emissions are not good for the environment and cause pollution. When hydrogen is burned, it only forms water as a by-product. Thus, since there are no hydrocarbon emissions, pollution is minimum.Therefore, looking at the effect on the environment, hydrogen is a cleaner and better fuel than CNG.

Additional Information: Even though hydrogen seems to be the better and cleaner fuel to use, it requires the implementation of fuel cells. These cells are costly and difficult to maintain. Hence, hydrogen fuel, although gaining popularity, is not being used in everyday machines. Looking at the environment, renewable sources like hydrogen are important to reduce pollution and prevent the complete depletion of natural resources as well.

Note: Such questions are fact-based. With simple knowledge of the different types of energy sources one can answer this question with ease. Remember to learn what makes a certain fuel or energy renewable and non-renewable.