Abstract: A process for the production of a range of improved biomass material products suitable for use as a fuel and which have been derived from municipal solid waste (MSW). The process comprises the steps of delivering a stream of mixed, MSW derived biomass material into a separator which operates under negative pressure enabling the biomass material to fall down the separator whilst inducing a sole air stream through the falling material to create a vortex of spinning material within the turbo chamber to separate out by centrifugal action selected denser components of the biomass material enabling such to continue falling to an outlet for collection whilst redirecting by entrainment in the air stream the remaining biomass material to a second outlet for subsequent processing or for collection.