Abstract:

The reuse-water system of the refinery wastewater treatment in a petrochemical company in northwest China was improved using pinch technology. Based on the data of the flow rates and impurity concentrations of the water to be treated each stage, the optimal retrofit solution was proposed, and then the benefit of the retrofit was evaluated. The measure which increased the processing capacity of the ultrafiltration device leads to the ‘cascade utilization’ for the reclaimed water with different processing depth, and consequently increases the utilization extent of reuse-water. Under the preconditions of the discharge standards of municipal sewage system, the consumption of fresh water is reduced by 158t/h, the amount of discharged wastewater is reduced to 259t/h, and the discharge reduction rate reaches 37.7%. The economic benefit of water conservation is up to 1.517 million RMB per year.

Key words: water conservation and wastewater reduction, wastewater treatment, reclaimed water reuse, pinch technology