Methane explosion suppression characteristics based on the NaHCO₃/red-mud composite powders with core-shell structure

Area of Science:

• Materials Science
• Chemical Engineering
• Safety Engineering

Background:

• Methane (CH4) explosions pose significant risks in various industrial settings.
• Effective suppression agents are crucial for mitigating explosion hazards.
• Red mud (RM), a byproduct of alumina production, and sodium bicarbonate (NaHCO3) are explored for their potential in explosion suppression.

Purpose of the Study:

• To develop and evaluate NaHCO3/RM composite powders for methane explosion suppression.
• To investigate the structural and performance characteristics of the composite powders.
• To determine the optimal loading of NaHCO3 for enhanced inhibition properties.

Main Methods:

• Preparation of NaHCO3/RM composite powders using a solvent-anti-solvent method.
• Characterization of the composite powders, including structural analysis (core-shell structure).
• Testing of methane (9.5% CH4) explosion suppression in a 20L spherical vessel and a 5L Perspex duct.

Main Results:

• NaHCO3/RM composite powders exhibited a core-shell structure and excellent endothermic performance.
• The composite powders demonstrated significantly better methane explosion suppression than pure RM or NaHCO3.
• Optimal NaHCO3 loading (35%) resulted in a 44.9% decrease in max explosion pressure, a 96.3% decrease in max pressure rise rate, and a 366.7% delay in pressure peak time.

Conclusions:

• The NaHCO3/RM composite powder is a highly effective agent for methane explosion suppression.
• The core-shell structure and endothermic properties contribute to the enhanced suppression performance.
• Optimizing NaHCO3 loading is critical for maximizing the inhibitory effect of the composite material.