Optimisation of eco-industrial park for water, waste, and energy nexus

Abstract
A sustainable economy promotes efficient usage of resources via reusing, recycling, and regenerating in order to minimize fresh resources consumption. Technically, minimization of fresh resource could be achieved through optimisation process that enables integration of energy, water, and waste network. However, there is lack of research attempting to further optimise a combined energy-water-waste nexus at inter-plant scale. In this study, the synthesis and design for an optimal network of energy-water-waste nexus at the eco-industrial park (EIP) level was investigated. A mathematical model to maximise water, energy, and waste recovery between industries via a centralized system in an EIP was developed. The model was extended to include economic analysis prior to performing sensitivity analysis and scenario analysis on the network to check its robustness. The developed superstructure consisted of multiple sources from different industries, multiple demand streams, and application of reuse, mixing, outsourcing, and regeneration strategies to obtain minimal energy, water, and waste network. The sources, which have a certain amount of pollutants, were also used to recover specific valuable resources. The installation of a regeneration unit that performs solid-liquid separation could further reduce pollutant amount, given that the regenerated stream could be sent to the mixer to be supplied to the demand. The recovered resources could provide additional revenue as well. The model was solved via the general algebraic modelling system (GAMS) software. The model was applied on the case studies. The results show a 78 % freshwater reduction per year, 2.3 MW renewable electricity power generation, 856 dry ton per year of struvite and 112 dry ton per year of metal hydroxide recovery. Additionally, 32 dry ton per year of ammonium sulfate and 47.5 GJ per year of heat can also be recovered feasibly. The baseline case study provided the annual profit of ~USD 2.3 million. The revenue from resource recovery work was relatively small, though it was emphasised in the concept of circular economy. The integration works offer technical, economic, and environmental benefits to the involving plants; these support the efforts towards sustainability and the circular economy practices.
Description
Thesis (PhD. (Chemical Engineering))
Keywords
Environmental economics--Research, Industrial ecology--Data processing, Robust optimization
Citation