Division BAT 20 In order to reduce emissions to water from the hydrofluoric acid alkylation process, BAT is to use a combination of the techniques given below.

United Kingdom

Technique	Description	Applicability
(i) Precipitation/Neutralisation step	Precipitation (with, e.g. calcium or aluminium-based additives) or neutralisation (where the effluent is indirectly neutralised with potassium hydroxide (KOH))	Generally applicable. Safety requirements due to the hazardous nature of hydrofluoric acid (HF) are to be considered
(ii) Separation step	The insoluble compounds produced at the first step (e.g. CaF₂ or AlF₃) are separated in e.g. a settlement basin	Generally applicable

Technique

Description

Applicability

(i)

Precipitation/Neutralisation step

Precipitation (with, e.g. calcium or aluminium-based additives) or neutralisation (where the effluent is indirectly neutralised with potassium hydroxide (KOH))

Generally applicable.

Safety requirements due to the hazardous nature of hydrofluoric acid (HF) are to be considered

(ii)

Separation step

The insoluble compounds produced at the first step (e.g. CaF₂ or AlF₃) are separated in e.g. a settlement basin

Generally applicable