Division BAT 54: In order to reduce the waste water volume and to reduce the organic load discharged from the product purification to final waste water treatment, BAT is to use one or both of the techniques given below.

United Kingdom

Technique	Description	Applicability
a.	Use of the purge from the EO plant in the EG plant	The purge streams from the EO plant are sent to the EG process and not discharged as waste water. The extent to which the purge can be reused in the EG process depends on EG product quality considerations.	Generally applicable
b.	Distillation	Distillation is a technique used to separate compounds with different boiling points by partial evaporation and recondensation. The technique is used in EO and EG plants to concentrate aqueous streams to recover glycols or enable their disposal (e.g. by incineration, instead of their discharge as waste water) and to enable the partial reuse/recycling of water.	Only applicable to new plants or major plant upgrades

Technique

Description

Applicability

Use of the purge from the EO plant in the EG plant

The purge streams from the EO plant are sent to the EG process and not discharged as waste water. The extent to which the purge can be reused in the EG process depends on EG product quality considerations.

Generally applicable

Distillation

Distillation is a technique used to separate compounds with different boiling points by partial evaporation and recondensation.

The technique is used in EO and EG plants to concentrate aqueous streams to recover glycols or enable their disposal (e.g. by incineration, instead of their discharge as waste water) and to enable the partial reuse/recycling of water.

Only applicable to new plants or major plant upgrades