| 摘要 |
A method for separating used oil in a simple batch process into usable fractions. A pretreatment step involves forming a mixture of the used oil and specified pretreatment chemicals. A reduced pressure is maintained throughout the process along with mixing of the formed mixture. Heat is applied at a predetermined rate corresponding to vaporization and recovery of usable fractions of aqueous, light hydrocarbons, base oil, and a pumpable residual. Each distillate fraction is removed as a vapor, condensed and collected. Undesirable cracking is avoided by maintaining a reduced pressure and avoiding rapid or localized heating within the mixture by mixing during the distillation process. The resulting aqueous and light fractions can be reused in the process or otherwise used. The pumpable residual can also be sold as a high quality asphalt extender. The recovered base oil fraction may be sold as a diesel fuel extender, lubricant, catalytic cracker feed stock, or #4 fuel oil for stationary power generators. The base oil fraction may also be further refined using NMP, lower alkanols, and/or water in a solvent extraction process. The described extraction process uses reduced solvent to base oil ratios and has significantly reduced residual solvent in the raffinate. The process effectively breaks the emulsion of used oil into usable fractions with minimal additional cracking or production of undesirable deposits or aromatics.
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