Abstract: A method is described for preparing hog fuel, other biomass, or peat for efficient burning and heat recovery in a water-wall boiler. The process requires drying the fuel to less that a 30% moisture content. The fuel is then pulverized to an upper particle size such that there are substantially no particles which will not burn in air suspension within the confines of the combustion zone and the boiler can meet emission requirements. Additionally, the pulverizing step is adjusted such that a fines portion of fuel is created of such size and in such amount that the fines portion readily self-ignites upon flame initiation. The fines provide sufficient ignition energy so that the entire flow of fuel burns without the necessity of the conventional fossil fuel support or pilot. The fuel is sized to burn in air suspension by injection into the boiler through a swirl stabilized-type burner.