A framework for designing inter-plant water networks in eco-industrial parks

Wastewater reduction and water conservation are becoming increasingly more important issues in the industrial parks. This paper develops a framework for the design of the inter-plant water networks in eco-industrial parks (EIPs). The framework is based on water quality classification in EIPs and water pinch technology. Opportunities for water reuse/recycle across plants are exploited. The aim of the work is to minimize the freshwater consumption. Firstly, the water-using units are categorized into two levels according to the water quality they demand. Effluent from units of the first level could be reused to those of the second level. Design of the network involves selected units of two levels and the wastewater regeneration facility. The minimum freshwater and wastewater flow rate targets of the network could be identified by water pinch technology, prior to its detailed design. An EIP case study from literature is presented to illustrate the proposed framework. This EIP includes five manufacturing plants and a wastewater treatment plant. The freshwater flow rate of the network is reduced from 49.63t/h to 18.86t/h after inter-plant water integration. Results show that the consumption of freshwater is reduced effectively.