Why is there a flame when firewood burns?

Flame is actually a burning phenomenon of combustible gas. Although firewood is not a combustible gas, once it is burned, it will undergo complex chemical changes, and soon the combustible gas will be released and burned again to form a flame.

Chemists have come to the conclusion that flame is a burning phenomenon of combustible gas. Cooking gas and gas welding calcium carbide gas (acetylene) are combustible gases, so these gases have flames at all. But matches and firewood are not gases. Why are there flames when they are drawn out? Matches and firewood are not combustible gases, but once they catch fire, they will undergo complex changes, and soon they will release combustible gases and burn to form flames.

So why is there no flame when charcoal burns?

As we know, charcoal is a dark brown or black porous solid fuel left by incomplete combustion of wood or wood raw materials or pyrolysis under the condition of air isolation.

Charcoal is an impure amorphous carbon, which keeps the original structure of wood and leaves tar in its pores. Charcoal was used in bronze wares of Shang Dynasty and ironware smelting in Spring and Autumn Period and Warring States Period in China, and its hygroscopicity was used to observe climate change.

Therefore, after processing, charcoal contains no combustible gas, only carbon, so it is flameless.