Oil demetalizing process
US5795463A · kind A · utility
Inventor
Key dates
| Filing date | Aug 5, 1996 |
| Grant date | Aug 18, 1998 |
| Priority date | — |
| Expiry date | Aug 5, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10M175/0016
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Metals are removed from used, contaminated oils, such as crankcase oils from cars, by a low temperature, batch tank process. The oil is hydrated by adding enough water to prevent premature crystallization of a reagent salt from solution in a succeeding stage of the process. The batch is heated to a low, required reaction temperature. A quantity of a primary demetalizing agent, comprising an ammonium based salt, or its requisite acid and base to from the salt in-situ, is added in the range of stoichiometric to multiples of stoichiometric, in accordance with the analysed quantum of metals present in the oil batch. The mixture is stirred to react the metals present with the salt, and is then cooled, to precipitate the thus formed sludge, which is then physically separated. The residual oil is reheated, rehydrated if necessary, and a secondary sequestering agent is added, comprising a metal complexing agent selected from the group comprising water soluble salts of ethylenediaminetetraacetic acid (EDTA), n-hexylamine, ethylenediamine, water-soluble salts of tartaric acid, and alkylbenzene-sulfonic acids, and compatible mixtures thereof, to complex any remaining metallic compounds, for r…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.