Performance Advantages of Amine-Treated Microspherical Silicas as CO2 Absorbents

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Carbon dioxide is a major driver of global warming, contributing to historic floods, storms and wildfires. It is also warming the Earth, which climate models predict will grow hotter by 7 degrees Fahrenheit by the end of the century.

To combat climate change, scientists are searching for ways to reduce pollution. One solution is carbon capture, which traps CO₂ molecules at emission sources before they can reach the atmosphere.

Why Carbon Capture Matters

Carbon capture is a key technology to combat the effects of climate change. It provides a way to offset emissions and prevent natural disasters. By removing CO₂ from the air, the United States can also make progress toward its goal to achieve net-zero emissions.

Two primary methods of carbon capture include:

Point Source Capture

This method of carbon capture takes place at the source of emissions — often coal or natural gas power plants. The technology uses porous particles, called solid sorbents, to extract carbon dioxide from flue gas released by smokestacks. Once captured, the CO₂ is stored underground or reused.

Direct Air Capture

Direct air capture (DAC) technology extracts carbon dioxide from the atmosphere at any location. Once CO₂ is removed, it is buried deep underground or repurposed. The United States is a global leader in this technology, with plans to create four DAC hubs over the next 10 years.

Introducing RESIFA™ SOLESPHERE™ Fine Silica for Carbon Capture

AGC Chemicals Americas has developed RESIFA™ SOLESPHERE™ silica particles, an effective solution for carbon capture. These advanced mesoporous silica grades are available in three forms: bare silica, silica pellets and amine-treated silica pellets.

Their key features that maximize CO₂ capture efficiency include:

• Highly porous structure: Their pore volume of up to 2.0 mL/g+ and pore diameter of 50 nm effectively traps and releases CO₂ molecules.
• Customizable solutions: Available in various particle sizes and porosity to meet your specific carbon capture needs.

SOLESPHERE Microspherical Silica Versus Other Materials

When paired with an amine treatment, AGC’s microspherical silica particles adsorb and release more carbon dioxide than zeolites and metal-organic frameworks (MOFs).

Zeolites

Zeolites are hydrated aluminosilicate minerals with porous structures. While these particles are inexpensive, they can degrade when exposed to water, which is present in flue gas. As a result, they can be less effective at capturing carbon dioxide. Zeolites also require large amounts of energy to release CO₂, which can contribute to carbon emissions.

Metal-Organic Frameworks

 Metal-organic frameworks (MOFs) are rigid, crystalline structures of metal ions and organic linkers. These particles have large surface areas that are ideal for carbon capture, but they are often expensive. MOF particles also have low hydrothermal stability, which can reduce their capacity to absorb CO₂ over time.

Why Microspherical Silica Is an Ideal Material for Carbon Capture

 While silica may not be inherently superior to other materials, SOLESPHERE microspherical silica particles stand out due to their unique pore structure. This structure allows them to adsorb and release more CO₂ than competing materials, and they do so at relatively low temperatures — reducing energy consumption and costs.

Key advantages of microspherical silica include:

Solid Carrier for Amine Treatments

Microspherical silica has a unique porous structure with a large surface area and pore volume, making it well-suited for amine treatments. When the pores are structured with AGC technology, the treated silica can efficiently adsorb and release higher amounts of CO₂.

 Superior Adsorption and Desorption Performance

 When paired with an amine treatment, microspherical silica maintains a high absorption capacity at various CO₂ concentrations. Additionally, amine-treated silica particles release CO₂ efficiently at low temperatures, requiring less energy for desorption. This energy-efficient silica is a cost-effective alternative to other CO₂ absorbents.

Ready to improve your carbon capture efficiency? Learn more about SOLESPHERE silica here.