Low-Cost CO₂ Capture Using Amine-Modified Coconut Shell Activated Carbon

What is it about?

This study investigates how carbon dioxide (CO₂), a major greenhouse gas responsible for global warming, can be captured using activated carbon made from coconut shells. Instead of relying on expensive commercial adsorbents or energy-intensive amine scrubbing processes, we produced activated carbon from locally available coconut shells and enhanced it through functionalization and activation processes. The coconut shells were carbonized and activated under controlled temperatures using nitrogen and steam to develop porous structures suitable for gas adsorption. The prepared activated carbon was then tested for its ability to capture CO₂ at different flow rates (1, 2, and 3 L/min), different masses (0.5 g, 1.0 g, and 1.5 g), and varying contact times (10–60 minutes). Results showed that CO₂ adsorption increased with time and adsorbent mass, reaching equilibrium at about 50–60 minutes. The highest CO₂ uptake occurred at 1.5 g dosage and 3 L/min flow rate, with a maximum uptake of 105 mg. Surface characterization using FTIR, BET, SEM, and TGA confirmed the presence of functional groups, porous morphology, and adequate surface area (328 m²/g), which explain the strong adsorption performance. The study demonstrates that coconut shell-derived activated carbon can serve as an effective and low-cost alternative for CO₂ capture from flue gases.

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Photo by Marcin Jozwiak on Unsplash

Photo by Marcin Jozwiak on Unsplash

Why is it important?

Carbon dioxide emissions from fossil fuel combustion are one of the primary drivers of climate change. While technologies like amine scrubbing are widely used for CO₂ capture, they are expensive and energy-intensive, limiting their accessibility in developing economies. This research provides a cost-effective and locally sustainable alternative by converting agricultural waste (coconut shells) into a high-performance adsorbent. The study not only reduces waste but also contributes to climate mitigation strategies through affordable carbon capture solutions. Importantly, the adsorption capacity achieved compares favorably with other adsorbents such as zeolites and kaolin. With a surface area of 328 m²/g and measurable adsorption capacities across varying flow rates, the material shows practical potential for industrial and laboratory applications. The work supports the development of scalable, low-cost carbon capture technologies, particularly relevant for coal-fired power plants and emerging economies seeking sustainable environmental solutions.

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