NOVELTY - A municipal solid waste (MSW) treatment apparatus comprises a feeding unit; two pressure vessels; an agitator for contents of one pressure vessel; a connection comprising a compressor between the vessels for transferring steam between them; and a classification section to classify treated waste to yield several fractions.    USE - An apparatus for treating municipal solid waste for making organic fiber-based fuel for providing green electricity (claimed).    ADVANTAGE - The apparatus improves energy consumption and/or use of energy in MSW treatment. Electricity is obtained from renewable resources in an efficient and effective way. The waste treatment obtains fuel obeying the Renewable Obligation Certificate (or equivalent green energy premium) type fuel requirements.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) waste treatment plant comprising the municipal solid waste treatment apparatus;    (2) integrated power plant and waste treatment plant, where heating requirement in the waste treatment plant is provided by steam supply of the power plant;    (3) a process for treating municipal solid waste in vessels used in an alternating fashion comprising feeding waste material into one pressure vessel; agitating the vessel while having steam pressure in the vessel; depressurizing the vessel and transferring the steam to another vessel with the aid of a compressor; discharging the first vessel; and classifying the treated waste, yielding several fractions;    (4) process for making organic fiber-based fuel comprising treating municipal solid waste in vessels; depressurizing the vessel and applying vacuum to the vessel to dry the fibrous content of the vessel to 40-60 wt.% water; classifying the treated waste through a screen to remove less than 12 mm fraction comprising less than 2 wt.% plastic (calculated on 60 wt.% moisture in the fibers); and treating the less than 12 mm fraction in an air classification device to yield a fibrous fraction comprising less than 2 wt.% inorganic material (calculated on 60 wt.% moisture in the fibers);    (5) method for providing green electricity by operating a power plant on site of MSW treatment plant and providing greater than or equal to 5% of the energy requirement of the power plant by using the fibrous fraction and having less than or equal to 2 wt.% inorganic material and less than or equal to 2 wt.% plastic material; and    (6) plant for making organic fiber-based fuel and providing green electricity.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a waste plant using an autoclave.    Screening area (2)    Hopper (3, 8, 14)    Feed conveyor (4)    Spray nozzle (5)    Autoclave vessel (6, 6')    Conveyor (7, 9, 11, 13, 15)    Trommel screen (10)    Air classification device (12)    Picking belt (16)    Magnetic and eddy current screening devices (17)    Heavies (18)    Fibers (19)