Systems and methods for processing mixed solid waste
Solid waste that includes a mixture of wet organic material and dry organic material can be are separated using mechanical separation to produce a wet organic stream enriched in wet organics and a dry organic stream enriched in dry organics. The separated wet organic stream and dry organic stream are separately converted to renewable or recyclable products using different conversion techniques particularly suited for the separated wet and dry organic streams.
1. A method for processing mixed solid waste, comprising:
providing a mixed waste stream comprising at least 10 wt % wet organic waste comingled with at least 10 wt % dry organic waste, at least a portion of the wet organic waste comingled with a flexible material;
fractionating the mixed waste stream by size to produce one or more sized waste streams;
fractionating the one or more sized waste stream by density to produce a plurality of intermediate waste streams having different densities, the plurality including at least a first intermediate waste stream that includes the portion of the wet organics comingled with the flexible material and a second intermediate stream enriched in dry organics; and
processing the first intermediate stream using a turbo separator, the turbo separator including breaker bars and being configured to separate wet organics from the flexible material, the processing with the turbo separator producing a flexible material stream enriched in the flexible material and an intermediate wet organic stream enriched in wet organics.
2. A method as in claim 1 , wherein less than 40 wt % of the mixed waste stream is separated as a recovered product using manual labor.
3. A method as in claim 1 , wherein less than 1 wt % of the mixed waste stream is separated as a recovered product using manual labor.
4. A method as in claim 1 , wherein the mixed waste stream includes at least 15% dry organic waste and at least 30% wet organic waste.
5. A method as in claim 1 , wherein at least 10 wt % of the mixed waste stream is dry organic waste selected from the group consisting of 3-D plastic, film plastic, paper, cardboard, rubber, textiles, and wood.
6. A method as in claim 1 wherein at least 10 wt % of the mixed waste stream is a wet organic waste selected from the group consisting of food waste, animal waste, and green waste.
7. A method as in claim 1 , wherein the throughput of the mixed waste stream is at least 10 metric tons per hour per single line of mixed solid waste.
8. A method as in claim 1 , wherein the second intermediate stream has less than 25% moisture content.
9. A method as in claim 8 , wherein at least a portion of the second intermediate stream is converted to a refuse derived fuel or electrical power.
10. A method as in claim 1 , wherein the mixed waste stream includes at least 20% by weight of low value material selected from the group consisting of wet organics, green waste, food waste, grit, fines less than 1 inch, asphalt, concrete, textiles, wood, rubber, film plastic, PVC, foil, rock, used consumer products, low value glass, composite materials, and combinations of these.
11. A method as in claim 1 , further comprising converting at least a portion of the first intermediate stream to one or more renewable products using at least a first conversion technique.
12. A method as in claim 11 , wherein the first conversion technique is selected from wet digestion, dry digestion, anaerobic digestion or composting.
13. A method as in claim 12 , wherein the first conversion technique produces biogas.
14. A method as in claim 13 , wherein the biogas is converted to a liquid fuel.
15. A method as in claim 1 , further comprising converting at least a portion of the second intermediate stream to one or more renewable products using at least a second conversion technique.
16. A method as in claim 1 , wherein the second intermediate stream includes fiber, the method further comprising converting the fiber to paper using a paper pulping process.
17. A method as in claim 1 , wherein the second intermediate stream includes PETE and/or HTPE and the PETE and/or HTPE is converted into a bottle, an insulation product, a packaging material, or combinations of these.
18. A method as in claim 1 , wherein the mixed waste stream includes aluminum, the method further comprising recovering aluminum from one or more of the plurality of intermediate waste streams.
19. A system for processing mixed solid waste, comprising:
a tip floor for receiving a mixed solid waste stream comprising at least 10 wt % wet organic waste comingled with at least 10 wt % dry organic waste, wherein the dry organic waste includes fiber and plastic and at least a portion of the wet organic waste is comingled with a flexible material;
one or more size separators configured to fractionate the mixed waste stream by size to produce one or more sized waste streams, each sized waste stream having an upper size cut and a lower size cut where the ratio of an upper cut-off to a lower cut-off is less than 8; and
one or more density separators configured to fractionate the one or more sized waste stream by density to produce at least a plurality of intermediate waste streams having different densities, the plurality including at least a first intermediate waste stream that includes the portion of the wet organics comingled with the flexible material and a second intermediate stream enriched in fiber and plastic;
a turbo separator including breaker bars and being configured to separate wet organics from the flexible material to produce a flexible material stream enriched in the flexible material and an intermediate wet organic stream enriched in wet organics;
one or more mechanical sorters configured to separate fiber material from plastic material in the second intermediate stream.
20. A method for processing mixed solid waste, comprising:
providing a mixed waste stream comprising at least 20 wt % wet organic waste comingled with at least 20 wt % dry organic waste, wherein the dry organic waste includes fiber and plastic and at least a portion of the wet organic waste is comingled with a flexible material;
fractionating the mixed waste stream by size to produce one or more sized waste streams, each sized waste stream having an upper size cut and a lower size cut where the ratio of an upper cut-off to a lower cut-off is less than 8; and
fractionating the one or more sized waste stream by density to produce at least a plurality of intermediate waste streams having different densities, the plurality including at least a first intermediate waste stream that includes the portion of the wet organics comingled with the flexible material and a second intermediate stream enriched in fiber and plastic;
processing the first intermediate stream using a turbo separator, the turbo separator including breaker bars and being configured to separate wet organics from the flexible material, the processing with the turbo separator producing a flexible material stream enriched in the flexible material and an intermediate wet organic stream enriched in wet organics;
sorting the second intermediate stream using a plurality of optical sorters to produce a sorted fiber material;
converting the sorted fiber material into paper using a paper pulping process;
recovering aluminum from at least one of the plurality of intermediate waste streams.