Process for treating sludge and manufacturing bioorganically-augmented high nitrogen-containing inorganic fertilizer
US7947104B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 19, 2008 |
| Grant date | May 24, 2011 |
| Priority date | — |
| Expiry date | Jul 31, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W10/40
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The invention describes a new method for treating sludge, which can result in the production of high nitrogen organically-augmented inorganic fertilizer that incorporates municipal sludges or biosolids or organic sludges that can compete with traditional fertilizers such as ammonium phosphate, ammonium sulfate and urea on the commodity fertilizer marketplace. The method takes advantage of the thixotropic property of dewatered biosolids or organic sludge to create a pumpable paste-like material from the biosolids or organic sludge that is then treated with an oxidizer to reduce odorant effects and an acid. This mix is then interacted with concentrated sulfuric and or phosphoric acids and an ammonia source or alternatively a hot or molten melt or salt of ammonium sulfate/phosphate to form a fertilizer mix. The present invention controls the heat, atmospheric pressure and retention time of the fertilizer mix in the reaction vessel. When a fertilizer melt is formed ammoniation is subsequently completed by the specific use of vaporized ammonia. The invention can also be an add-on to commercial production of ammonium salts. The fertilizer produced by the present invention contains more t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.