NOVELTY - The apparatus has casing (108) having inlet (202) to introduce dry solid content at high pressure above atmospheric pressure in a direction parallel to radius of rotating cylinder (111) having protrusions with rotating elements (110) to generate mixing zones. An inlet is provided to feed steam at different doses to mixing zones, and outlet (204) is provided to discharge mixed content. The rotating cylinder is provided with channels to inject steam, and protrusions to generate unsteady fluctuating velocity distribution such as vortex dominated flow.    USE - Apparatus for fluffing and mixing steam and biomass such as lignocellulose-based material, used in production of bio-ethanol gas (both claimed).    ADVANTAGE - The loss in the mechanical energy can be avoided and the heating losses can be reduced reliably while optimizing the overall speed of the fluffing and mixing process. The back flash problem can be avoided and the plug flow condition can be created effectively while enabling continuous feed of biomass.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) system for producing bio-ethanol from biomass which includes pre-processing subsystem for collecting, transporting, reducing to pulp, comminuting and delivering material to processing apparatus. A reactor is provided for changing the chemical and physical structures of the material;    (2) method for processing two media using a processing apparatus which involves injecting steal into mixing zone while solid content is comminuted;    (3) method of utilizing processing apparatus which involves producing heat transfer between heated gas and dry solid content;    (4) method for mixing two media which involves achieving intimate contact between the media; and    (5) method for opening structures of organic materials such as lignocellulose-based material.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of the apparatus for fluffing and mixing steam and biomass.    Reaction chamber (102)    Casing (108)    Rotating elements (110)    Rotating cylinder (111)    Inlet (202)    Outlet (204)