In the context of which one of the following are the terms ‘pyrolysis and plasma gasification’ mentioned?
Answer & explanation
Answer: (d) Waste-to-energy technologies
Pyrolysis and plasma gasification are waste-to-energy technologies: they treat waste (such as plastics and municipal solid waste) at high temperature and turn it into fuel oil or syngas that can generate power.
- ✓ (d) In pyrolysis, waste is heated (400-600°C) without oxygen to give pyrolysis oil and gas. In plasma gasification, a plasma arc above 3000°C turns waste into syngas, which can run gas engines to make electricity.
- ✗ (a) Rare earth elements are recovered from ores by mining and chemical processing, not by these thermal waste treatments.
- ✗ (b) Natural gas extraction uses drilling and hydraulic fracturing; neither term belongs there.
- ✗ (c) Hydrogen vehicles run on fuel cells or hydrogen engines; pyrolysis and gasification are not vehicle technologies.
Remember · Pyrolysis (heating waste without oxygen) and plasma gasification (waste to syngas in a plasma arc above 3000°C) are waste-to-energy routes for plastics and solid waste.
Sources
- PIB, Ministry of Science & Technology: Sustainable Processing of Municipal Solid Waste, 'Waste to Wealth' (23 Oct 2020) ↗ “The polymer waste consisting of plastics, sanitary waste etc. is being disposed of through two main processes i.e. pyrolysis and plasma gasification. … The produced syngas when passed through a series of gas purification system comprising of catalytic converter, redox reactor, cyclone separator, scrubber and condenser is ready for use in gas engines for generation of electricity.”
Question and answer: UPSC's official GS Paper I (2019, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·