Why Does Wood Burn

“Why does wood burn?” is one of those questions the pursuit of whose answers kept the primitive man in an enigmatic haunt. You would have definitely read or performed some thing while you were a grade reader in your elementary school. Those who haven’t been to this experience must have been indulging the fire burning of wood in their childhood for fun, hiding it from your elders somewhere in the neglected corner of your house.

Man for a long time was not able to answer the “why” of this question. Did you come across with the answer when the smoke started erupting? Whether did you hint on the chemical reaction behind these smoke curls or not but you were prevented from any further practical exploration under the prejudiced layer of common sense: “Keep burning wood out of the reach of inquisitive children.”

Wood Burns Why Does Wood Burn

Of all the organic matter, the DRIED WOOD burns quick:

Protoplasm is predominantly organic in nature with carbon, hydrogen and oxygen and the fundamental constituents in its composition. It is this third element, oxygen that ignites the matter.

A dried wood easily catches fire because of little amount of water in it. The componential burning of carbon and hydrogen further augments the process of ignition. Despite of all these positive indicators, all wood won’t catch fire quickly.

Normally, wood is prone to catch fire very quickly but before that it has to reach a certain temperature, called the “Flash point”. At this threshold wood issues gases from the spot of ignition considered the interface between the point of flame and the surface that seems to be undergoing ignition but actually not. Interface, identified as the colorless thin film, is the site of rapid succession of oxidation-reduction process liberating some 900 oF heat energy.

Composition of Wood

Organic compounds present in a wood’s composition are highly volatile to spontaneous burning. This character of wood is more prominent in its sap or bark for the “sap” is rich in glucose contents and glucose in turn is highly combustible material. On the contrary, there are some negative factors also, such as the presence of inorganic compounds, viz. layers of calcium, potassium and magnesium that inhibit the rate of combustion.

The smoke that evolves from the surface of the burning wood consists of hydrocarbons, the product of a typical combustion process. It is at this threshold 300 oF temperature that the smoke starts to appear from out of the burning wood. A slight increase beyond this sharp threshold point of ignition would result in a full-scale fire — a phenomenon we commonly see in daily life.

On the other hand, when we burn charcoal, no significant fire is seen; it is because this substance has pure carbon in it. However, the insignificant color of charcoal flame is due to the presence of the traces of hydrogen and glucose. This leaves us to conclude that the color of flame of wood fire is predominantly because of other two elements, hydrogen and oxygen.

Utility of Wood

The decaying process of wood doesn’t need any catalyst (stimulant) such as bacteria or the like and hence considered as “biodegradable’ waste that adds to the fertility of soil. Green wood helps to maintain cool environment.

Similarly, it requires fewer amounts of energies to burn as compared to other (metallic) substances. Wood transforms into different products that have unique uses; in other words its utility is renewable, no absolute expiry — a great natural source.

Wood has a wide-scale usage in erection and fabrication such as; building of wooden enclosures and scaffoldings, pathways, lumber works, etc. To many fashion designers and artists, wood is much more appealing and pleasant than any other substance for decoration purposes.

Fire in action:

We know even before pre-historic period, the use of fire was not just confined to keeping oneself warm at night. The primeval man was acquainted with a variety of uses of fire ranging from lighting, roasting to use as a weapon by inflicting wounds on wild animals both for hunting and safety purposes. The ancient people used to highlight / flag spots of their interest in the dark at night in forests; this aided them in hunting. Over the course of their hunt, they analyzed that the auto-ignition of grass was most suitable for the better growth of the forest next time as it enriched the fertility of the soil by providing it with organic wastes for the observation would have confirmed by the time they saw ever growing fields replete with a variegated flowers and plants.

There has been a drastic global weather change over the span of a couple of last centuries; in the present scenario one would hardly wish a tropical fire.

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