Home › PYQs › Environment › All questions › 2017 · Algal biofuels
UPSC Prelims 2017 · Environment · Warming World
It is possible to produce algae-based biofuels, but what is/are the likely limitation(s) of developing countries in promoting this industry? Select the correct answer using the code given below:
- Production of algae-based biofuels is possible in seas only and not on continents.
- Setting up and engineering the algae-based biofuel production requires high level of expertise/technology until the construction is completed.
- Economically viable production necessitates the setting up of large-scale facilities which may raise ecological and social concerns.
- (a) 1 and 2 only
- (b) 2 and 3 only
- (c) 3 only
- (d) 1, 2 and 3
Show the answer and explanation
Answer: (b) 2 and 3 only
Technology and scale are the real limits.
Statement by statement
1. ✗ WRONG Algae can be grown on land in ponds and closed photobioreactors.
2. ✓ CORRECT Building production systems needs high technology and expertise.
3. ✓ CORRECT Viable output needs big facilities, which can raise land, water and social concerns.
The idea
Algae grow very fast, some are rich in oil, and they do not need farmland: they can be grown in ponds or closed tanks, even with salty or waste water. So they do not compete with food crops. The problems are cost, technology and scale.
Algae grown in open ponds or closed photobioreactors → Harvested and dried → Oil is extracted → Converted to biodiesel → Each step is costly and energy-hungry
The trap
“Only” in statement 1.
Elimination technique
Statement 1 says “in seas only”. Absolute words usually mark the false statement in Environment PYQs. That removes (a) and (d).
Also know
Algal fuel is called a third-generation biofuel. Large ponds need a lot of water, nutrients and land, which is where the ecological and social concerns come from.
🔒 Algal biofuel = 3rd generation; open ponds or photobioreactors.