Practice Tests
IELTS Reading (AC) Task 1 #142

A. Carbon Capture, Utilisation, and Storage (CCUS) is a suite of technologies designed to mitigate climate change by capturing carbon dioxide (CO2) emissions from large point sources, such as power plants and industrial facilities. The primary goal is to prevent this greenhouse gas from entering the atmosphere. Once captured, the CO2 is compressed and transported, typically via pipeline, to a site where it can be either utilised in other industrial processes or permanently stored in deep underground geological formations.

B. There are several different methods for capturing CO2. Post-combustion capture involves separating CO2 from the flue gases after a fossil fuel has been burned. Pre-combustion capture involves converting the fuel into a mixture of hydrogen and CO2 before it is burned, after which the CO2 is separated. A third method, oxy-fuel combustion, involves burning the fuel in nearly pure oxygen instead of air, which results in a flue gas that is almost entirely CO2 and water, making the CO2 much easier to capture.

C. After capture, the CO2 can be utilised to create products like concrete, chemicals, or fuels, which can provide an economic incentive for the process. However, the largest potential for climate mitigation lies in long-term storage. The captured CO2 is injected deep underground into porous rock formations, such as depleted oil and gas reservoirs or saline aquifers, which are typically located a kilometre or more beneath the surface. These formations are overlain by an impermeable cap rock that traps the CO2 and prevents it from escaping.

D. CCUS is considered by many scientists and policymakers to be a critical technology for achieving ambitious climate targets, particularly for decarbonising heavy industries like steel and cement manufacturing, where emissions are difficult to abate. However, the technology faces significant challenges, including high costs, large energy requirements for the capture process, and public concerns about the long-term safety and permanence of CO2 storage. As such, it is generally viewed as part of a broader portfolio of climate solutions, alongside renewable energy and energy efficiency, rather than a single silver bullet.