Process for disposing of sewage sludge
US5217625A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 1992 |
| Grant date | Jun 8, 1993 |
| Priority date | — |
| Expiry date | Oct 2, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W10/40
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A process for disposing of sanitary sewage sludge by producing a pumpable slurry of sewage sludge with or without solid carbonaceous fuel and burning said slurry as fuel in a partial oxidation gas generator, furnace, or boiler. First, an aqueous slurry of sewage sludge is concentrated to produce sewage sludge cake. The sewage sludge cake is preheated and sheared while in contact with sulfuric or sulfurous acid to produce a pumpable acidified aqueous slurry of sewage sludge having a pH of about 1 to 5. After two-stage hydrothermal treatment with neutralization of the sewage sludge after the second hydrothermal stage, the solids content of the pumpable aqueous slurry of sewage sludge is increased. By means of the subject process, the viscosity of the slurry of sewage sludge with or without solid carbonaceous fuel is reduced and coagulation is suppressed. A pumpable aqueous slurry of sewage sludge with or without solid carbonaceous fuel is produced and burned with a free-oxygen containing gas in a partial oxidation gasifier, furnace, boiler, or incinerator to produce a hot raw effluent gas stream. In a preferred embodiment, the effluent gas stream is cleaned and purified and non-conta…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.