Question 25 from UPSC CSE 2019 - Environment

Question

In the context of which one of the following are the terms 'pyrolysis and plasma gasification' mentioned?

IASCODEX · Accepted Answer

Correct Option: D. Waste-to-energy technologies

Strategy: Focus on the core processes implied by the terms 'pyrolysis' and 'plasma gasification'—both denote thermal decomposition of organic matter, which aligns directly with waste-to-energy conversion. The presence of 'gasification' suggests turning waste into useful gases, not extraction or automobile technology. This eliminates other options and points squarely to waste-to-energy.

Key Info: **Pyrolysis**
Pyrolysis is a thermochemical process that decomposes organic materials at elevated temperatures in the absence of oxygen, producing products such as bio-oil, syngas, and char. It is widely used for converting municipal solid waste, plastics, and biomass into useful fuels and chemicals.

**Plasma Gasification**
Plasma gasification employs extremely high temperatures, generated by plasma torches (ionized gas), to break down waste into syngas—mainly hydrogen and carbon monoxide—alongside an inert slag byproduct.

**Application and Distinction**
Both processes are significant in modern waste management strategies under waste-to-energy schemes, as they minimize landfill use and generate usable energy products. These methods are distinguished from natural gas extraction (physical or chemical extraction of geological resources), rare earth extraction (complex mining and chemical processes), and hydrogen-fuel automobile technology (primarily involving fuel cells or hydrogen storage), none of which utilize pyrolysis or plasma gasification as primary technologies.

IASCODEX · Answer

Option A: Extraction of rare earth elements

IASCODEX · Answer

Option B: Natural gas extraction technologies

IASCODEX · Answer

Option C: Hydrogen fuel-based automobiles