Eli5 why is there no liquid wood


Assuming no oxygen is around could we melt wood?

In: 0

Wood is a very complex material made of various organic compounds that melt or break apart at different temperatures.

If you were to heat wood in an environment with no oxygen various chemical reactions will occur.

First the water and lightweight volatile materials will boil out. Then, the hydrocarbon structure of the wood will start to turn into charcoal.

If there is adequate sap or resin it will leach out as pine tar.

Increasing the temperature will cause other compounds to break down and eventually evaporate until you are left with a lump of carbon which won’t start to melt until over 3300 degrees Celsius.

Wood is a large collection of different molecules bonded in various ways. Instead of melting, if you apply sufficient heat to wood those bonds start to break down and the molecules get broken into different forms. Some of the result will be a liquid and flow or boil away, others will sublimate into gases directly, others will remain solid and require far more heat before they break down and go through similar processes. Plenty of the processes would be anaerobic and would happen regardless of oxygen.

In addition to what others have said, some pure substances of only one molecule type, such as in the case of dry ice aka frozen solid carbon dioxide, does not have a liquid stage.

It is called sublimation when a substance directly transitions from a solid to a gas state, and while that is not quite what wood is going through when it is heated into charcoal, the point is that not everything “melts” into a liquid form above its solid state temperature.

Feels like we have the same question asked here as we dod a few hours ago, that one was why we can’t melt diamonds like glass.

For the same reason, wood and other plants are fiber based, those fibers break down to complex carbon chains. Carbon as explained earlier, at our atmospheric pressures, doesn’t have a liquid phase. There’s solid, and gas, add energy to carbon and it gets hot then burns. The same is said for wood.

Take plants and compress for millions of years and you end up with fossilized hydrocarbons, aka crude oil. The closest we’d be able to find liquid wood on this planet.

Wood is not a single substance. wood is made up of thousands of different compounds, each with different melting points (in fact, some organic compounds don’t have melting points at all; they decompose into different molecules if you try to heat/pressurize them too much), so wood doesn’t have a melting point in the same way that water, iron, and salt do, since wood isn’t a single compound like those other things.

If you heat up a piece of wood in the presence of oxygen, the wood will just burn (i.e., undergo combustion, a permanent chemical reaction) and you’ll be left with carbon and a whole bunch of other gasses like carbon monoxide, carbon dioxide, sulfur oxides, and nitrogen oxides.

If you heat up wood in a vacuum or otherwise not in the presence of oxygen, the individual chemicals that make up wood will either melt individually, react, or decompose. Mostly, you’ll end up with carbon dioxide, water vapor, and and carbon.


Also, [this was just asked a few weeks ago,](https://www.reddit.com/r/explainlikeimfive/comments/14qbjz9/comment/jqm9czv/?context=3) so please search first next time.