Answer: If a fuel has a lower combustion temperature, generates a significant amount of warmth, and has a higher carbon content, it is called excellent or valuable. A good fuel does have these specific traits:
(I) It should be reasonably priced and widely accessible.
(II) Its heat of combustion should be higher than normal.
(III) It must be simple to use and transport.
(IV) This should not emit any harmful substances during combustion and must not leave the waste or ashes behind.
(V) The rate of burning should be constant and predictable.
(VI) It must have a high heating value, which means this should create a lot of energy per unit volume or mass.