Fire, which can transform from an atmosphere- enhancing candle to a devastating blaze in seconds, is at its most basic level a series of chemical reactions. Understanding the way that the element of fire is created can inspire respect for the ways in which this element can be used for good – cooking, ambiance – or for destruction, in the case of neglected flames that get out of control.
What is fire, really?
Fire is a chemical process. Chemical processes either absorb energy or release it as molecules rearrange themselves. The chemical process present in fire is called oxidation, which which oxygen atoms combine with hydrogen and carbon to form water and carbon dioxide.
Fire arises when oxygen in the atmosphere reacts with a type of fuel, such as wood or gasoline. To complete the combustion response, you must use heat to fuel the ignition temperature. How does this occur?
Fuel gets hot: Be it a match, focused light, friction, or lightning, a force outside of the fuel itself must heat up the wood, paper, or fabric until it reaches a state of decomposition.
Fuel decomposes: Once the fuel reaches approximately 300 degrees Fahrenheit (150 degrees Celsius), it begins to decompose. Some of the decomposed material releases in the form of volatile gases, known as smoke, which is composed of hydrogen, carbon, and oxygen. These gases release into the air as smoke.
Char develops: The reminder of the material turns to char. Char is almost pure carbon and ash, which includes the unburnable minerals in wood (calcium, potassium, etc.). When you purchase charcoal, you are essentially buying char, or wood that has been heated to remove most of the volatile gases, leaving the carbon behind. Charcoal fires produce no smoke because those volatile gases have already absorbed into the air.
How does combustion work?
Fire lights when a combustion reaction takes place. Combustion occurs when fuel reacts with an oxidizing agent , releasing energy in the form of heat or light. In the case of fire, the fuel is usually wood, gasoline, or coal, combined with oxygen.
At best, fire creates warmth and light. At worst, it can demolish your home. By understanding the way in which fire is created, you can more accurately grasp how this powerful chemical reaction can be used and contained in your daily life, and the safety precautions necessary to make sure it never causes a home fire.