The Cokemaking department has a complicated water balance. Water is used primarily for quenching coke and for cooling gas at the Gas Processing Plant. The quality of water required for gas cooling is higher than that for quenching.
A large air conditioning system has once through water cooling. The used cooling water was historically fed to the water make-up circuit for the quencher.
An improvement opportunity was identified where, due to the quality of the used air conditioning water, it could be diverted from the quencher circuit to the gas cooling circuit. This reduces the amount of fresh water used for gas cooling and also allowing additional recycled water to utilised in the quenching circuit.
As part of implementing the project, it was determined that the water feed to the air conditioning system could also be reduced by 30%.
The total water saving from the project is in the order of 150 kL/day.