| 208 / | HD | MINERAL OILS: PROCESSES AND PRODUCTS |
| 177 | DF | REFINING {23} |
| 208 R | DF | .~ Sulfur removal (free or combined sulfur) {17} |
| 226 | DF | .~.~ With alkali or alkali earth metal compound (except clays) {4} |
| 230 | | .~.~.~ Alkali metal compound {2} |
| 231 | DF | .~.~.~.~> With added oxygen containing organic compound {2} |
| 235 | DF | .~.~.~.~> With regeneration of treating agent |