Activated carbon derived from waste coffee grounds for stable methane storage.

Area of Science:

• Materials Science
• Chemical Engineering
• Sustainable Energy

Background:

• Developing efficient and stable materials for gas storage is crucial for energy applications.
• Waste valorization, such as using coffee grounds, offers sustainable routes to novel materials.
• Activated carbons are widely explored for gas adsorption due to their porous structures.

Purpose of the Study:

• To investigate the potential of waste coffee grounds as a precursor for activated carbon.
• To evaluate the methane and hydrogen storage capacity of the derived activated carbon.
• To understand the formation mechanism and structural evolution of activated carbon from coffee grounds.

Main Methods:

• Pyrolysis and activation of waste coffee grounds at elevated temperatures (900 °C).
• Characterization of the activated carbon's surface area (1040.3 m²/g) and micropore volume (0.574 cm³/g).
• Gas adsorption measurements for methane (CH4) and hydrogen (H2) under varying pressures and temperatures.

Main Results:

• The activated carbon derived from coffee grounds exhibited a high surface area and micropore volume.
• Stable methane (CH4) adsorption capacity of ~4.2 mmol/g at 3.0 MPa and 298 K.
• Significant hydrogen (H2) storage capacity of 1.75 wt% at 77 K and 100 kPa.

Conclusions:

• Activated carbon from waste coffee grounds is a viable and stable medium for methane and hydrogen storage.
• Elevated temperature activation is key to developing high surface area porous structures.
• This research presents a sustainable pathway for producing advanced materials for energy storage.