A combustion control system, including a first set of sensors for generating sample data including data representing a sequence of detected images of different samples of a fuel made up of solid particles; a fuel analysis module for controlling a processor of a computing device to: (i) determine attributes for one or more predetermined physical characteristics of the particles in each said sample based on the sample data, and (ii) generate an index value for each said sample based on said attributes, said index value representing a level of combustibility of the particles in each said sample; and a combustion control module for controlling a processor of a computing device to adjust one or more parameters for controlling a combustion process based on changes to said index value over time.