Liquid organic hydrogen carriers energy storage in urban-industrial symbiosis through process integration

The urban industrial symbiosis is a concept that reasonably represents the application of the circular economy concept, in which the energy symbiosis can reduce overall fuel consumption and ultimately reduce carbon emissions. Energy storage is one of the essential components for stabilising the energy supply and demand fluctuations due to renewable energy, urban energy consumption, and industrial consumption. Hydrogen-based energy storage is a promising storage option, along with heat or battery storage. This study proposes a Pinch-based methodology for targeting energy savings for thermal and power systems. This paper introduces the Hydrogen Storage Cascade (H2SC) to target the hydrogen-based energy storage capacity, which is currently assumed based on liquid organic hydrogen carriers (LOHC) storage, which chemically bonds hydrogen molecules to stable organic liquid carriers to avoid the compression or liquefication of hydrogen to make it saver and more cost-effective. The methodology can be adopted for other types of hydrogen-based energy storage systems. An illustrative case study with industrial processes, urban residential and renewable energy to demonstrate the proposed methodology using LOHC-based energy storage. This study found that the LOHC-based energy storage can reduce the energy utility cost by 59,148 million MYR/y (35.8 % reduction). The study compares the hydrogen-based storage system with the heat and battery storage systems. It is found that a power storage system has a great potential to reduce utility costs with a payback period of 0.89 year. The capital cost calculated for the hydrogen energy storage system is too high, making it less attractive. In addition, heat storage causes a reduction in the power cogeneration potential, which significantly affects the power supply and causes a reduction in excess electricity to generate income.