Methane hydrate burning snowball

Fig. 5 The burning snowball. Methane hydrate decomposing to gas, which is burning, and water. (Photo courtesy of the GEOMAR Research Center, Kiel. Germany.) (View this art in color at www.dekker.com.)...

Figure 7.1 Burning snowballs of methane clathrate hydrate (image courtesy of the US Geological Survey).

Clathrate hydrates are inclusion compounds formed by the enclosure of a small guest molecule within a hydrogen bonded cage of solid-state water. Clathrate hydrates are co-crystals and are thus distinct from ice, which is made of pure water, and hence can have different physical properties to ice such as a different melting point. The classic example of a clathrate hydrate is the burning snowball of methane clathrate hydrate. The combustion of the methane in the clathrate is self-sustaining, Figure 7.1. Many... 

The burning snowball is an often-repeated pyrotechnic demonstration (Fig. 5). Methane hydrate is allowed to warm to the point where the surface begins to decompose, and the evolved methane can be ignited (methane hydrate requires 26 atmospheres pressure of methane at 273 K to keep it stable). The burning snowball... 

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