Division BAT 62: In order to prevent or reduce emissions of organic compounds to air and emissions to water of organic substances from the vacuum systems, BAT is to use one or a combination of the techniques given below.
United Kingdom
| Technique | Description | Applicability | |
|---|---|---|---|
| a. | Water-free vacuum generation | Use of dry-running pumps, e.g. positive displacement pumps | Applicability to existing plants may be restricted by design and/or operational constraints |
| b. | Use of water ring vacuum pumps with recirculation of the ring water | The water used as the sealant liquid of the pump is recirculated to the pump casing via a closed loop with only small purges, so that waste water generation is minimised | Only applicable when technique a. cannot be applied. Not applicable for triethanolamine distillation |
| c. | Reuse of aqueous streams from vacuum systems in the process | Return aqueous streams from water ring pumps or steam ejectors to the process for recovery of organic material and reuse of the water. The extent to which water can be reused in the process is restricted by the water demand of the process | Only applicable when technique a. cannot be applied |
| d. | Condensation of organic compounds (amines) upstream of vacuum systems | See Section 12.1 | Generally applicable |