Method for reducing heavy metal content of sludge-based biocoke
US11643350B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 2021 |
| Grant date | May 9, 2023 |
| Priority date | — |
| Expiry date | Sep 4, 2041 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W10/40
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
The disclosure relates to a treatment method for sludge utilization in a sewage treatment plant, in particular to a method for reducing heavy metal content of sludge-based biocoke. The disclosure includes following steps (1) to (5): step (1): concentrating a residual sludge produced by a municipal sewage treatment plant to be with a moisture content of 95-98%; step (2): conditioning the concentrated sludge in a sludge bioleaching tank for 48 hours, with a pH value of the sludge being reduced to below 4.5; step (3): pumping the conditioned sludge into a high-pressure diaphragm plate and frame for a press filter dewatering to obtain a dewatered cake with a moisture content less than or equal to 50%; step (4): delivering the dewatered cake into a sludge dryer for crushing, heating and drying to obtain the dried sludge with a moisture content of 15-22%; and step (5): carbonizing the dried sludge into sludge-based biocoke at a high temperature in a pyrolytic carbonization device with a carbonization temperature of 500-650° C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.