Process to recover a portion of post-recycling municipal solid waste
This specification describes a system and process for treating waste, for example municipal solid waste (MSW) or post-recycling municipal solid waste. The system includes a press and a pulper. The press is adapted to provide a wet fraction of the waste suitable for anaerobic digestion and rejects. The pulper is adapted to receive the rejects and produce pulp. The pulper may be, for example, a drum pulper. In the process, waste is separated into a press into an organic fraction and rejects. The organic fraction is treated by way of anaerobic digestion. The rejects are separated, optionally in a drum pulper, to produce a fraction containing pulp. The pulp can be re-used to make paper or other products. In some case, 70% or more or 80% or more of MSW can be diverted from landfill.
1. A solid waste treatment system comprising,
a press for separating solid waste into a fluidized fraction and rejects; and,
a pulper,
wherein the pulper receives rejects from the press.
2. The system of claim 1 wherein the pulper is a drum pulper or a tub pulper.
3. The system of claim 1 wherein the press comprises a perforated extrusion chamber and a corresponding plunger.
4. The system of claim 1 further comprising an anaerobic digester that receives at least a portion of pulp from the pulper.
5. The system of claim 1 further comprising a pyrolyzer that receives at least a portion of pulp from the pulper.
6. A process for treating solid waste comprising the steps of,
pressing the solid waste to produce a wet fraction and rejects; and,
extracting pulp from the rejects.
7. The process of claim 6 wherein the process of extracting pulp comprises diluting the rejects with heated water, tumbling the diluted rejects and screening the diluted rejects.
8. The process of claim 6 wherein the pulp is extracted using a drum pulper or a tub pulper.
9. The process of claim 6 wherein the step of pressing comprises bursting cells in the waste.
10. The process of claim 6 comprising using the pulp to make a paper product.
11. The process of claim 6 further comprising treating at least a portion of the pulp by anaerobic digestion.
12. The process of claim 6 further comprising treating at least a portion of the pulp by pyrolysis.