Question 45 from UPSC CSE 2025 - Environme nt & Ecology

Question

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.

Accepted Answer

Correct Option: C. I, II, and III

Strategy: Identify the main capability — Direct Air Capture removes CO2 directly from ambient air, so it fits carbon sequestration. Its captured CO2 is a feedstock for industrial uses, including plastics and some food applications (like carbonation), and, critically, can be combined with hydrogen for making synthetic fuels, especially for aviation. All three statements match core applications and current research focus. Thus, all statements are correct.

Key Info: Direct Air Capture (DAC) is a set of technologies that extract carbon dioxide (CO2) directly from the ambient air. DAC is distinct from point-source carbon capture, which targets emissions from specific industrial sites.

• Carbon sequestration: DAC can permanently sequester CO2 by injecting it into deep geological formations (such as depleted oil and gas fields or saline aquifers), contributing to negative emissions and climate targets. This is a recognized method under the IPCC and used in some commercial carbon removal projects (e.g., Climeworks in Iceland).

• Industrial and product uses: Captured CO2 from DAC can be utilized as a feedstock in various chemical syntheses. It is used in manufacturing plastics (e.g., polycarbonates), carbon fibers, construction materials (e.g., carbonates in cement), and for food and beverage industry applications (carbonation of soft drinks, food preservation processes).

• Synthetic fuels and aviation: In Power-to-Liquid (PtL) or e-fuel processes, CO2 captured via DAC is combined with green hydrogen through Fischer-Tropsch synthesis or methanol pathways to produce synthetic hydrocarbons. This approach is being explored globally, particularly for aviation fuel, as it offers one of the few scalable low-carbon solutions for the aviation sector, helping reduce lifecycle emissions by recycling atmospheric CO2.

• Current status: Several pilot plants worldwide (e.g., Carbon Engineering, Climeworks) are scaling up DAC deployment, though cost and energy consumption remain challenges. Policy tools like carbon credits and investments in negative emissions are driving adoption.

Answer

Option A: I and II only

Answer

Option B: III only

Answer

Option D: None of the above statements is correct