Benchmarking water utilisation using minimum water network

Abstract

This paper describes a procedure to establish the minimum utility targets, which relates to the maximum potential utility savings for a manufacturing plant. The focus is on setting the best achievable, or the minimum water and wastewater benchmark targets for a semiconductor plant using a new procedure known as the minimum water network (MWN) technique (Manan and Wan Alwi, 2006). The procedure involves detailed analysis of a plant configuration, material and energy balances, design and thermodynamic constraints. The minimum water network (MWN) technique can help a company realize its’ best achievable water savings target and assess its true potential for continuous improvement as part of its quality management requirement. Application of MWN technique on a semiconductor plant in Malaysia showed that savings of up to 85.5% fresh water and 97.8% waste water were achievable with an estimated payback period of less than half-a-year. The proposed detailed improvement schemes and targets provided a useful guideline for the semiconductor plant short and long term water-saving program.