UPSC Prelims 2009 Q143: Environment & Ecology – Renewable Energy & Green Technologies

UPSC Prelims 2009, General Studies Paper I · Environment & Ecology

In the context of alternative sources of energy, ethanol as a viable bio - fuel can be obtained from

Answer: (c) Sugarcane

Explanation

Which crop is a viable bio-fuel source for ethanol

Among these options, one is the classic, most commercially significant source for ethanol production.

Option	Verdict	Reason
(a) Potato	Incorrect	Not the standard major ethanol source crop
(b) Rice	Incorrect	Also not the primary ethanol source crop in this context
(c) Sugarcane	Correct	Sugarcane, particularly via its molasses by-product, is a major, well-established source for ethanol production as a bio-fuel
(d) Wheat	Incorrect	Also not the primary ethanol source in this context

Ethanol bio-fuel source facts:

Point	Detail
Primary crop	Sugarcane (via molasses)
Use	Blended with petrol as a bio-fuel

Answer: (c) Sugarcane.

(a) Incorrect. Potato is not the standard major ethanol source crop.
(b) Incorrect. Rice is also not the primary ethanol source crop in this context.
(c) CORRECT. Sugarcane (via molasses) is the major, well-established ethanol bio-fuel source.
(d) Incorrect. Wheat is also not the primary ethanol source crop here.

Sugarcane, through its molasses by-product, is the major, well-established source for ethanol bio-fuel production.

Ethanol as a viable bio-fuel can be obtained from sugarcane.

Confusing sugarcane's ethanol-production role with other starch/grain crops.
Not knowing the molasses-to-ethanol production pathway.
Mixing up various crops' different bio-fuel roles (ethanol vs bio-diesel).

Sugarcane (via molasses) = the classic ethanol bio-fuel source, distinct from oil-seed crops used for bio-diesel.

Ministry of Petroleum and Natural Gas, Government of India — Ethanol Blended Petrol Programme (2003)
Ministry of New and Renewable Energy, Government of India — National Policy on Biofuels (2009)