Factors for evaluation | Thin film evaporation process | Vacuum disitillation with clay treatment process | Acid clay process | Direct clay treatment process | Distillation followed by solvent extraction |
Lube yield | 65 - 75% | 65 - 75% | 60 - 62% | 54 - 60% | 65 - 75% |
Utilities consumption | High | High | Low | Low | High |
Energy consumption | Low | Low | Low | Low | Low |
Process | Semi-continuous / continuous | Batch / continuous | Batch | Batch | Continuous |
Hazardous chemicals | None | None | Acid | None | None |
Residue | 10 - 12% | 10 - 12% | None | None | 12 - 15% |
Acid sludge | None | None | High | None | None |
Spent clay | 2.5 - 6% | 2.5 - 6% | 8 - 10% | 2.5 - 306% | None |
Heating | Indirect | Indirect | Direct | Direct | Indirect |