| 208 / | HD | MINERAL OILS: PROCESSES AND PRODUCTS |
| 177 | DF | REFINING {23} |
| 208 R | DF | .~ Sulfur removal (free or combined sulfur) {17} |
| 209 | DF | .~.~ With hydrogen {4} |
| 213 | DF | .~.~.~ With solid catalyst or absorbent {4} |
| 216 R | ![]() | .~.~.~.~ With group VI metal or compound {1} |
| 216 PP | DF | .~.~.~.~.~> With specific porosity or pore volume |