Catalyst for distributed batch microwave pyrolysis, system and process thereof
The present document describes a catalyst to initiate microwave pyrolysis of waste, a process for the microwave pyrolysis of waste using the catalyst, as well as a microwave pyrolysis system.
1. A pyrolysis process for domestic or municipal waste which comprises the steps of:
a) steam purge of a domestic or municipal waste in a media: and
b) pyrolysis of said domestic or municipal waste in said media using a catalyst and a microwave for a time sufficient to allow generation of heat providing a thermal treatment between 300° C. and 600° C. through absorption of microwaves by said catalyst and said media
wherein said catalyst comprises a carbon-based compound to absorb microwaves, transfer heat to microwave-transparent waste and initiate a pyrolysis reaction, and
wherein said carbon based compound is the carbonaceous residue from a previously performed pyrolysis reaction.
2. The pyrolysis process according to claim 1 , wherein said waste undergoes thermal depolymerization to form a microwave absorbent.
3. The pyrolysis process according to claim 2 , wherein said microwave absorbent allows a further generation of heat through absorption of microwaves and a thermal depolymerization of an unreacted waste.
4. The pyrolysis process according to claim 1 , wherein said pyrolysis process is for distributed pyrolysis of waste, is an at source process, is a small scale to a medium scale process, or combinations thereof.
5. The pyrolysis process according to claim 4 , wherein said small scale to a medium scale process is from about 1 kg to about 40 kg of waste.
6. The pyrolysis process according to claim 1 , wherein said process is batch operated.
7. The pyrolysis process according to claim 1 , wherein no oxygen is added to said process.
8. The process according to claim 1 , wherein said steam purge is performed at a temperature of about 20° C. to about 100° C.
9. The process according to claim 1 , wherein said steam purge is performed for about 5 to about 120 min.
10. The process according to claim 1 , wherein during said steam purge is performed, a temperature of said waste is about 150° C. or less.
11. The process according to claim 1 , further comprising the addition of water, of an acid, or a combination thereof, to said waste prior to said steam purge.
12. The process according to claim 1 , wherein said waste is shredded prior to said steam purge.
13. The pyrolysis process according to claim 1 , wherein said process comprises air in a stoichiometric balance with said waste.
14. The pyrolysis process according to claim 1 , wherein said microwave has frequency from about 915 MHz to about 2450 MHz.
15. The pyrolysis process according to claim 1 , wherein said process has a reaction temperature from about 300° C. to about 400° C.
16. A gas produced by the pyrolysis process according to claim 1 , having an energy content of about 8 megajoules/m 3 to about 15 megajoules/m 3 .
17. A condensable hydrocarbon oil produced by the pyrolysis process according to claim 1 , having an energy content of about 15 megajoules/kg to about 22 megajoules/kg.
18. A carbonaceous by-product produced by the pyrolysis process according to claim 1 , having a carbon content of at least about 80% by weight.
19. The carbonaceous by-product according to claim 18 , wherein said by-product may be used as a catalyst in a pyrolysis reaction.