Optimum water network using process integration and sustainable process index

• Main Author: Ku, Valarie S.
• Format: text
• Language: English
• Published: Animo Repository 2004
• Subjects: Process control; Water reuse; Integrated water development
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/3151
• Institution: De La Salle University

Process water integration studies have focused on reducing the amount of water used by a process on the assumption that environmental impact is reduced through efficient water reuse. However, the environmental impact of retrofitting the water network through the installation of pumps and pipes and energy for their utilization which may even lead to a network with a higher environmental cost as measured using a more comprehensive metric. Using the Sustainable Process Index (SPI), an established means of measuring environmental impact, this study combines the concepts water integration and environmental impact and shows that there is a balance that must be struck between water savings and water network modifications. A mathematical model that combines the two concepts was constructed and the model was applied to an actual case study with multiple contaminants. In addition, sensitivity analysis was made by using two hypothetical cases, one by increasing the flowrate of the original case study by 10-fold still with multiple contaminants and a second one where data was sourced from a published study and considers a single contaminant. For the second hypothetical case study, arbitrary plant distances were assumed. Results prove the premise that the effect of introducing pumps, pipings and utilizing them has an effect on the environmental impact. In one case study, the Sustainable Process Index of the minimum fresh water scenario (conventional Process Water Integration methodology) is even higher than that of the current no reuse scenario. However, capital costs implications is outside the scope of this study. Being a new study, several improvements can be added to this research in the future. The author recommends a combination of process integration, Sustainable Process Index and capital cost for investors and actual plant managers to see the bigger picture.