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UPSC Prelims 2025, Question 36

The concept being tested: Direct Air Capture (DAC) — carbon sequestration and synthetic fuel production.

With reference to 'Direct Air Capture', an emerging technology, which of the following statements is/are correct? I. It can be used as a way of carbon sequestration. II. It can be a valuable approach for plastic production and in food processing. III. In aviation, it can be a source of carbon for combining with hydrogen to create synthetic low-carbon fuel. Select the correct answer using the code given below.

Options

  1. AI and II only
  2. BIII only
  3. CI, II and IIICorrect answer
  4. DNone of the above statements is correct

The answer: I, II and III

Direct Air Capture extracts carbon dioxide directly from ambient air using chemical sorbents or solvents, and the captured CO2 can then be injected underground for permanent geological storage, making DAC a genuine carbon sequestration route, so statement I holds. Once captured, this CO2 is not just buried; it is increasingly used as an industrial feedstock. It can be converted into polymers for plastics manufacturing and used in food and beverage processing for carbonation and modified-atmosphere packaging, which validates statement II. In aviation, captured CO2 can be combined with green hydrogen, typically via a Fischer-Tropsch-type synthesis, to produce synthetic low-carbon jet fuel, an approach several e-fuel pilot projects already use, confirming statement III. Since DAC supports sequestration, industrial utilisation and synthetic fuel production simultaneously, all three statements describe genuine, established applications, making 'I, II and III' the correct combination.

What UPSC was testing

This is a three-statement 'select the code' format designed to test whether aspirants know DAC beyond sequestration alone; many wrongly assume it is only a storage technology and eliminate the industrial-utilisation and synthetic-fuel statements as too specific or futuristic.

How often this comes up

This concept has appeared 8 times in UPSC Prelims General Studies Paper I between 2015 and 2025 — in 2016, 2019, 2023, 2024 and 2025.

The option-by-option autopsy for this question — why each of the other three is wrong, and which neighbouring concept each one was built from — is in the app.

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