Design of integrated energy-water systems using pinch analysis: a nexus study of energy-water-carbon emissions

Abstract

Severe environmental issues such as excessive energy and water resources consumption and massive carbon emissions are becoming progressively prominent. Energy, water and carbon emissions are also intrinsically linked and have become the critical indicators for sustainable development. Nexus analysis between the three resources has been increasingly emphasised, mainly using mathematical programming approaches. Applications of insight-based approach for nexus study, however, have been directed very few attentions. This paper presents a new framework for the optimal design of integrated energy-water systems based on Pinch Analysis considering the energy-water-carbon emissions nexus. The framework consists of a series of Pinch Analysis methods, specifically Power Cascade Table (PCT), Water Cascade Table (WCT) and Energy Planning Pinch Diagram (EPPD), to obtain the minimum targets for each resource. The established targets provide valuable insights to assess the whole integrated system following any design modifications on certain resource networks. The framework was tested on a small-scale industrial plant case study, where adjustments on the system design were performed to achieve 20% CO2 gas discharge reduction target. The final integrated design gave minimal impacts of up to 12% changes on the energy system, while the water system deviates by less than 1% from the initial design. The outputs from the framework can assist designers in the planning of their integrated energy-water systems while meeting the environmental requirements.