1. Optimization of Industrial Water Networks
Sule Abdullahi
Supervisors: Prof. Joe Akunna, Dr Ruth Falconer
School of Science, Engineering & Technology
Abertay University
Abstract
Methodology
Preliminary Results
This research aims to optimise the design of water reuse networks for different industries, while considering single-contaminant and multicontaminant wastewater. By maximising freshwater reuse and recycling of wastewater this will lead to minimization of freshwater used in an industry. It is proposed that by combining Water Pinch Technology (WPT), Water Source diagram (WSD) with Genetic Algorithms (GA) that this offers a robust and easy to use framework for decision makers to make savings. Future work will look at balancing other objectives such as economic savings and GHG.
Water Pinch Technology (WPT), Water Source diagram (WSD) and mathematical programming are the key approach to optimization for this research. The objective function and constraints in equation below are solved using Genetic Algorithm (GA), and the system analysed for optimum result. Optimization toolbox of MATLAB software was used as a solver. The model used for the analysis is shown in Figure 2. It involve optimisation of single-contaminant, multicontaminant processes and interconnections of water and wastewater systems among the processes.
Figure 2: The model
Table 1: Comparison of Results obtained for single contaminant water reuse without regeneration and Literature
Number of processes
Water use without optimization
(ton/h)
Genetic Algorithm (GA) Minimum fresh water result (ton/h)
Literature Minimum fresh water result
Reduction % 3 90
56.667
56.670 37 4
134
90.1 33 5 65 30 58
Genetic Algorithm parameters:
Introduction
Water is intensively utilised in food, pulp or paper, pharmaceutical, petrochemical and chemical industries. The wastewater generated in the processes of those industries is normally treated in a central common facility in order to remove contaminants and to meet regulatory specifications for disposal. As opposed to this conventional approach, water-reuse, recycling, and regeneration-reuse/recycle in an integral water network helps in reducing the consumption of freshwater, and minimizes the amount of wastewater to be treated and disposed as illustrated in figures 1.
Future Work
To design a framework for optimizing water reuse network capable of handling multicontaminant and addressing multiobjective. The Sensitivity analysis of water reuse optimization model and obtaining Genetic Algorithm (GA) parameters. Considering new treatment technologies that can improve regeneration and recycling of waste water and GA parameters that pertain to nonconvexity, nonlinearity and uncertainty of the problem global optimum solution.
Conclusion
In this research, an improved and general framework for optimising water (fresh and waste) use applied to different industries was developed. Genetic algorithms (GAs) was used to optimize the water-using networks problem. It was tested and the results are compared to the ones from literature.
References
1. Prakotpol, D., and Srinophakun, T :. GA Pinch: genetic algorithm toolbox for water pinch technology, Chemical Engineering and Processing 43 (2004) 203–217
2. LAVRIC, V., IANCU, P. and PLEŞU, V., Genetic algorithm optimisation of water consumption and wastewater network topology. Journal of Cleaner Production, 13(15), pp
3. LI, B., ZHANG, G., YE, M., DU, J., XIANG, X., QUAN, X., YANG, F., XU, X. and MA, S., Network optimization and performance evaluation of the water-use system in China's straw pulp and paper industry: a case study. CLEAN TECHNOLOGIES AND ENVIRONMENTAL POLICY, 18(1), pp
Acknowledgements
Petroleum Technology Development Fund
(PTDF) Nigeria.
Figure 1: Different water reuse minimization method