Modelling Seawater Desalination With Waste Incineration Energy Using Dynamic Systems Approach

Abstract

Water shortage issues have been growing concerns in many cities around the world in recent years, especially in Eastern cities of Australia, which is the driest continent on the earth. The aim of this PhD thesis is a development of a model to study the use of waste incineration energy supplemented by alternative energy to power seawater desalination. It is to aid the freshwater supply of a drought stricken city in Eastern Australia. My work contributes to a development of efficient model in a simpler understandable way to reduce efforts required for modelling complex multi domain problems. This research is motivated by the successive severe drought conditions that affected many Australian cities in the past few years, compounded with an additional strain from a fast growing population. While we dump our waste into the Australian landscape, in more densely populated cities in Europe and Asia, the waste is incinerated to obtain thermal energy for various purposes. The waste is used as an energy source while at the same time reducing the amount of space needed for landfill. Seawater desalination has been uccessfully practiced for quite some time particularly in the Middle Eastern countries. To deal with increasing water shortage crisis, many cities around the world have opted or are considering seawater desalination to supplement their freshwater supply. The combination of both - waste incineration and seawater desalination - has rarely been studied. This is a twofold problem that requires modelling the problem of water demand and supply together with waste incineration to find a sustainable solution. This is a complex task. The effort needed for this can be reduced by using a modelling approach that is more efficient than the traditionally used statistical approaches. In this thesis, I present a comprehensive model developed using a dynamic system approach combined with artificial neural networks. It simulates water demand and supply as well as the possible amount of the desalinated water that can be produced using the energy from clean city waste incineration. This is done while taking in various influential factors including population growth and irregular weather patterns. This research comprises a literature review on seawater desalination and waste incineration, the establishment of water demand and supply dynamics of Gold Coast City as my case study and identifying any modelling difficulties that need to be overcome. This is followed by the development of a comprehensive model and its components, model calibration and simulation experiments. It was found that with the energy of waste incineration, up to 60% of the freshwater demand could be fulfilled by seawater desalination in a sustainable way.