Is carbon flammable


What is left after burning ashes?


Combustion is a process in which a fuel is oxidized by oxygen at a high temperature and forms new chemical compounds. This releases heat and light. Like any organic substance, wood as a fuel essentially consists of carbon and hydrogen. These are linked in molecules that are built into the wood cells. A piece of wood now consists of millions of wood cells. When burned, these molecules react with oxygen and carbon dioxide and water vapor gas are produced, both of which rise in the smoke. So wood would burn without ashes.

In fact, a tree also needs other elements to live, such as sodium, calcium, magnesium, potassium, aluminum and phosphorus, which are built into the molecules of the wood cells. When burned, these oxidize and, when completely burned, remain in the gray powdery ash. However, the combustion is often not complete. To understand this, let's look at how wood burns. This is done in three stages: drying, firing and glowing. In the first two, the high heat "evaporates" the wood and wood gas is produced. If there is a lack of oxygen, this wood gas does not burn but rises as smoke. The embers consist only of carbon. If the embers are now surrounded by gray powdery ash, the oxygen no longer comes to the carbon and the embers go out. That is why one often finds charred pieces of wood in the ashes. These are nothing more than the charcoal that you can buy in the supermarket. If you take them out of the ashes and light them up again, you can grill some good sausages.