Apparatus and method for processing municipal waste into bio-ethanol

Abstract

A process and apparatus for recycling municipal domestic waste comprises subjecting the waste to steam at 150° C.-200°. After steam treatment, the resultant material is separated into constituent parts and biomass and/or plastics subjected to further treatment. The further treatment preferably produces bioethanol from the biomass and diesel from the plastics. As an alternative, some or all of the biomass may be gasified in order to produce hydrogen which may, in turn be fed to a fuel cell to produce an electrical output. The bio diesel or bioalcohol can also be used to produce electricity.

1 . An apparatus for extracting bio-fuel from solid waste material, the apparatus comprising:
 an inner drum ( 10 ) with an inlet for waste material to be introduced at one end and an outlet at the other end, wherein the inner drum is rotatable about its axis; and   an outer drum ( 22 ) at least partially surrounding the inner drum ( 10 ) and rotatable thereabout, wherein the outer drum ( 22 ) is adapted to receive said waste material from the outlet of the inner drum and is provided with an outlet to output treated said waste material, characterised in that the apparatus comprises means ( 24 ) for introducing steam into the interior of the inner drum ( 10 ) and is configured so that in operation the interior of the drums is substantially at ambient pressure.   
     
     
         2 .- 30 . (canceled) 
     
     
         31 . The apparatus of  claim 1 , wherein the outlet of the second drum ( 22 ) is located at the same end of the apparatus as the inlet of the inner drum ( 10 ) and said waste material is received from the inner drum towards the other end. 
     
     
         32 . The apparatus of  claim 31  wherein means ( 24 ) for introducing steam into the interior of the inner drum comprises a hollow shaft with perforations through which steam is injected into the interior of the inner drum. 
     
     
         33 . The apparatus of  claim 1  further comprising heating means for heating the inner drum ( 10 ), and wherein the heating means is selected from the group consisting of heated air, a heating jacket ( 18 ), an exterior steam jacket, and a heating element. 
     
     
         34 . The apparatus according to  claim 1 , wherein the outer drum ( 22 ) rotates in the opposite direction to the inner drum. 
     
     
         35 . The apparatus according to  claim 33 , wherein heating means heat, and maintain, the interior of the inner drum ( 10 ) at a temperature of 160° C. to 180° C. 
     
     
         36 . The apparatus according to  claim 1  wherein the interior of the drums is at a pressure under 2 bar. 
     
     
         37 . The apparatus according to  claim 1 , wherein said means for introducing steam into the inner drum comprises steam inlets into the interior of the inner drum ( 10 ). 
     
     
         38 . The apparatus according to  claim 37  wherein the steam inlets ( 24 ) are fixed relative to the interior of the inner drum ( 10 ). 
     
     
         39 . The apparatus according to  claim 1 , wherein steam is injected into the apparatus at a temperature of 150° C. to 200° C. 
     
     
         40 . The apparatus according to  claim 1 , further including means for transferring said waste material from the inlet of the inner drum ( 10 ) to the outlet of the outer drum ( 22 ). 
     
     
         41 . The apparatus according to  claim 1 , wherein the treated said waste material comprises a biomass of cellulose material containing less than 1% sulphur. 
     
     
         42 . The apparatus according to  claim 1 , wherein the outlet is connected to a sorting chamber where the treated said waste material is separated into plastics, ferrous metals, non-ferrous metals and biomass of cellulose material. 
     
     
         43 . The apparatus according to  claim 42 , wherein said biomass is transferred to a hyperbaric engine, a fuel cell, or a conversion unit for converting the biomass into biodiesel or an organic alcohol, such as bio-ethanol or bio-butanol, or an aviation fuel. 
     
     
         44 . The apparatus of  claim 43 , wherein the apparatus further includes electrical generators powered by the biodiesel or organic alcohol. 
     
     
         45 . The apparatus of  claim 1  wherein the outer drum ( 22 ), surrounds the inner drum ( 10 ) such so as to provide a radial overlap, and wherein the radial overlap is at least half of the length of the inner drum, is at least three quarters of the length of the inner drum or extends over substantially all of the length of the inner drum. 
     
     
         46 . A method for treating waste material comprising the steps of:
 a) inputting waste material into an apparatus according to  claim 1 , and   b) treating the waste material with steam at a temperature of 150° C. to 200° C. in the first cylinder or inner drum.   
     
     
         47 . The method of  claim 46  wherein steam is injected only in to the waste material. 
     
     
         48 . The method of  claim 46  wherein the waste material is particulate waste material or biomass. 
     
     
         49 . The method according to  claim 48 , wherein the biomass is further treated to form a fuel selected from: biodiesel, fuel for a fuel cell, bio-alcohol, aviation fuel or a substitute fossil fuel.