Chin H.H., Jia X., Varbanov P.S., Klemeš J.J., Wan Alwi S.R., 2021, Targeting Flowrates and Concentrations in Internal Or Total Site Water Mains for Single Contaminant, Chemical Engineering Transactions, 86, 895-900.
This work aims to extend the Pinch-based approach, namely the Material Recovery Pinch Diagram to identify the minimum numbers of water mains/headers required, flowrates and concentrations of the contaminants inside the water mains/headers. The freshwater target should be first determined using the Source and Sink Composite Curves (CC) representations. The header lines can then be drawn along the Source CC to determine the optimal mixing of the water sources that the contaminant limits for the sinks are not violated, while guarantees the freshwater target is still achieved. The attributes of the header lines represent the properties of the headers. The number of segments in the header lines represent the minimum number of headers required, the horizontal length of the segment represent the flowrates inside the water mains and the gradient of the segment is the concentrations of the contaminants inside the header. The methodology can be applied to both process and site-level scale. The approach is flexible for different scenario including single Pinch Point problem, multiple Pinch Points problem and threshold problem. A case study is used to elucidate the proposed methodology. The proposed method is beneficial as it provides a graphical interface for the header targeting and design for the decision-makers. The lengths and gradients of the header lines can also be tweaked by the users as long as the header lines are below the Sink CC.
