Activated carbon from coffee and plastic waste captures CO2 in project by female-led Arab team

A team of researchers in the United Arab Emirates has turned everyday trash into a potential climate tool: spent coffee grounds and plastic bottles are being combined and transformed into activated carbon that can pull carbon dioxide from industrial emissions. The method has been patented and aims to tackle two pollution problems at once—organic waste that releases methane in landfills and single-use plastics that persist for centuries.

Their approach mixes used coffee grounds, polyethylene terephthalate (PET) from plastic packaging, and potassium hydroxide to produce a highly porous adsorbent. Laboratory tests indicate this activated carbon is effective at capturing CO₂, offering a low-cost route to create industrial-scale sorbents from widely available waste streams.

From cups and bottles to CO₂-capturing material

The research centers on converting two abundant waste flows into value. Worldwide, an estimated eight million tons of spent coffee grounds are discarded every year, often ending up in landfills where they emit methane and other greenhouse gases. PET, a common polyester used in beverage bottles and packaging, accumulates in the waste stream and presents recycling challenges.

Scientists at the University of Sharjah developed a synthesis that blends these ingredients with potassium hydroxide (KOH), a potent activating agent. When processed under controlled heat, the mixture forms activated carbon with a vastly increased surface area and pore structure suitable for gas adsorption.

How the activation process works and why it matters

The team’s process harnesses chemical activation rather than relying solely on high-temperature thermal decomposition. Key features include:

• KOH activation: Potassium hydroxide etches the carbon matrix, creating micro- and mesopores that trap CO₂ molecules.
• Lower operating temperature: The activation is carried out at around 600 °C, which is lower than many thermal recycling routes for plastics, reducing energy input.
• Waste-to-resource conversion: Coffee grounds supply organic carbon and structure, while PET contributes an additional carbon source and material consistency.

Researchers say this route can produce high-performance adsorbents suitable for capturing CO₂ emitted by fossil-fuel-based power plants and industrial processes.

Potential applications and industrial uses of the activated carbon

Activated carbon is already a staple in a variety of purification and treatment systems. The new material produced from coffee and PET could be used in:

• Gas purification and CO₂ adsorption units
• Drinking water filtration systems
• Wastewater and sewage treatment
• Pool and aquarium filtration

Because the feedstocks are inexpensive and plentiful, the technique may offer a scalable, lower-cost source of adsorbent media compared with conventional materials.

Environmental benefits and waste reduction

By diverting coffee grounds from landfills and reusing PET, the method addresses multiple environmental pressures:

• Reduces organic waste that would otherwise decompose and release methane.
• Provides an outlet for plastics that are difficult to recycle mechanically.
• Generates a product that can help limit CO₂ emissions when installed in industrial exhaust streams.

The inventors emphasize the circular-economy angle: what starts as a disposable cup and a single-use bottle can be converted into a tool for pollution control.

Who’s behind the innovation and where it could go next

The work was led by Dr. Haif Aljomard and colleagues at the University of Sharjah. Their patent describes the detailed synthesis steps and the performance characteristics of the resulting activated carbon. Dr. Aljomard notes that the patent documents demonstrate the feasibility of synthesizing effective adsorbents from common wastes and point toward commercial possibilities.

Next steps for the technology include scale-up trials, integration into pilot CO₂ capture systems, and lifecycle assessments to quantify net climate benefits. If these stages prove successful, manufacturers of filtration media and companies working on carbon-capture solutions may adopt the approach as an affordable, sustainable feedstock option.

Challenges and considerations for adoption

Several factors will determine whether the innovation reaches wide use:

• Feedstock logistics: collecting and transporting spent grounds and PET in sufficient quantities.
• Production costs: ensuring the activation process remains economically favorable at scale.
• Durability and regeneration: assessing how many capture cycles the activated carbon can withstand and whether it can be regenerated efficiently.
• Regulatory and market acceptance: meeting standards for industrial adsorption systems and convincing stakeholders of performance and cost advantages.

Why this approach could attract attention from industry and policymakers

Transforming waste into functional materials aligns with global goals for circular economies and emissions reduction. The dual benefit—cutting landfill emissions while producing media that sequester CO₂—makes the technology attractive to municipal waste managers, beverage companies, and industries seeking lower-cost carbon-capture options.

If the patent holders can demonstrate reliable performance in real-world settings, this coffee-and-plastic route to activated carbon could become a practical tool in efforts to cut pollution and reuse waste.

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Michael Thompson

Michael Thompson is an experienced journalist covering U.S. and global news. With ten years on the front lines, he breaks down political and economic stories that matter. His precise writing and keen attention to detail help you grasp the real‑world impact of every event.