This invention pertains to a bio-mass processing system, and method of processing waste bio-mass, wherein one or more mixers mixes a bed of bio-mass material such as manure at substantially any and all locations in a defined length and width portion of the bed, in a dryer. Heated air percolates upwardly through the bed. Separation apparatus separates a relatively dryer fraction of the bio-mass material from the dryer. The separated finished product from the dryer is optionally fed to a boiler where the dried bio-mass material is burned. Heat of combustion from the boiler is used as dryer heat for drying the bio-mass feed material in the dryer. Excess heat is optionally used to produce steam, which powers a turbine, which powers an electrical generator. Residual ash from the combustion process comprises about 2% by weight of the solids content of e.g. a feed stream coming into the dryer.