Division 8 Generation of waste
United Kingdom
BAT 16: In order to reduce the quantity of spent sulphuric acid sent for disposal, BAT is to use one or a combination of the techniques given below. The neutralisation of spent sulphuric acid from chlorine drying with virgin reagents is not BAT.
| Technique | Description | Applicability | |
|---|---|---|---|
| a | Use on site or off site | The spent acid is used for other purposes, such as to control the pH in process and waste water, or to destroy surplus hypochlorite. | Applicable to sites with an on-site or off-site demand for spent acid of this quality. |
| b | Reconcentration | The spent acid is reconcentrated on site or off site in closed-loop evaporators under vacuum by indirect heating or by strengthening using sulphur trioxide. | Off-site reconcentration is restricted to sites where a service provider is located nearby. |
The BAT-associated environmental performance level for the quantity of spent sulphuric acid sent for disposal, expressed as H2SO4 (96 wt-%), is ≤ 0,1 kg per tonne of chlorine produced.