By Yee Heng Ang and Dominic C. Y. Foo, University of Nottingham Malaysia |
By exploring strategies for process integration, such as waste-heat recovery and combined heat and power generation, plants can significantly improve their energy efficiency and reduce utility costs
In a chemical processing plant, utility costs typically account for about 10 to 20% of the total product cost . Advancements in systematic techniques for better utilization of energy, such as through process integration, had received recognition following the fuel crisis in the 1970s . Apart from economic reasons, improving energy management also brings environmental advantages, such as reductions in greenhouse-gas emissions.
Process integration can be defined as a holistic approach to design and operation that emphasizes the unity of the process [3, 4]. Since the 1970s, various process-integration tools have been developed for heat-exchanger network synthesis, as well as for the optimization of various energy-intensive processes, and are well documented in literature [5, 6]. Two such important tools showing the relationship between heat flow and temperature are the heat-recovery pinch diagram and the grand composite curve (GCC), both shown in Figure 1.
FIGURE 1. Two of the most important tools for design optimization of energy-intensive…