Division BAT 22 In order to prevent and reduce the emissions of hazardous substances to air and water from base oil production processes, BAT is to use one or a combination of the techniques given below.
United Kingdom
| Technique | Description | Applicability |
|---|---|---|
| (i) Closed process with a solvent recovery | Process where the solvent, after being used during base oil manufacturing (e.g. in extraction, dewaxing units), is recovered through distillation and stripping steps. See Section 1.20.7 | Generally applicable |
| (ii) Multi-effect extraction solvent-based process | Solvent extraction process including several stages of evaporation (e.g. double or triple effect) for a lower loss of containment | Generally applicable to new units. The use of a triple effect process may be restricted to non-fouling feed stocks |
| (iii) Extraction unit processes using less hazardous substances | Design (new plants) or implement changes (into existing) so that the plant operates a solvent extraction process with the use of a less hazardous solvent: e.g. converting furfural or phenol extraction into the n-methylpyrrolidone (NMP) process | Generally applicable to new units. Converting existing units to another solvent-based process with different physico-chemical properties may require substantial modifications |
| (iv) Catalytic processes based on hydrogenation | Processes based on conversion of undesired compounds via catalytic hydrogenation similar to hydrotreatment. See Section 1.20.3 (Hydrotreatment) | Generally applicable to new units |