I am not sure what you mean. What process is that? Any combustible fuel will work, not just coal. You can read about the thermodynamics part by looking for a description of the "Carnot engine". The process is NOT reversible; although the Carnot engine is reversible in theory, there are always losses in practice that make it irreversible; also, the fact of burning the coal is not reversible.
A combustion reaction takes place when a fuel and an oxidant react, producing heat or heat and light. The most recognizable form of combustion reaction is flame, with explosions being an even faster form of combustion reaction. A combustion can happen at a wide range of speeds, and can occur in many different environments, but the majority of combustions we know and recognize happen in a fairly limited spectrum.
"Combustion engine" is a pretty generic term.Arguably the aeolipile was a very simple combustion engine, and it was described by Hero (that's a name, not a title) of Alexandria in the 1st Century.James Watt patented his steam engine in 1781.Robert Stirling developed an external combustion engine that did not use steam in 1816.The first internal combustion engine that we'd today recognize as an "engine" was probably the one developed by Christiaan Huygens (you may have heard the name before; he's more famous as an astronomer) in the 17th Century. It ran on gunpowder and was designed to operate water pumps for the palace gardens at Versailles.
"Combustion engine" is a pretty generic term.Arguably the aeolipile was a very simple combustion engine, and it was described by Hero (that's a name, not a title) of Alexandria in the 1st Century.James Watt patented his steam engine in 1781.Robert Stirling developed an external combustion engine that did not use steam in 1816.The first internal combustion engine that we'd today recognize as an "engine" was probably the one developed by Christiaan Huygens (you may have heard the name before; he's more famous as an astronomer) in the 17th Century. It ran on gunpowder and was designed to operate water pumps for the palace gardens at Versailles.
Please fell free to add / edit the answers provided. Others will do the same. Some answerers may edit your comments and make final adjustments to your words to the point you do not recognize the wording. But such is reversible, at need.
The Egyptians had batteries and Romans did not recognize the value of "zero", so they could not possibly have understood the concept of positive and negative, so necessary for the understanding of electricity.
recognize
I recognized my childhood friend immediately when I saw her at the airport.
To recognize the border
recognise
The suffix of "recognize" is "-ize."
The adverb for "recognize" is "recognizably."
Yes, they recognize them by smell.