You can not turn [Compact Hard Coal] Into [Coal-Infused Combustion Particle]
It takes 360 units of [Hard Coal] which is = to about 288 KiloSpark
total Input is 288 KiloSpark
For an output of 50 Units of [Compact Hard Coal] which is = to about 7500 KiloSpark
Which means the Output is 2504% more then the Input
However
The other reaction uses [Hard Coal] and only 180 units of it or about 144 KiloSpark, Since the farming stuff grows on its own and you are not leaving your base to go out and collect it, one might be able to say you are kind of getting it as a free material. since if it is setup correctly, it replaces itself with little effort.
So with that in mind and you count it as free, then turning 144 KiloSpark worth into 9000 KiloSpark worth is now a 6450% bonus. and this is what I think the fuel farming was designed to do, You can get a lot more out of the Hard Coal per unit, for less, if you are willing to count your farm as „free materials“
.