Industrial waste heat recovery with Central Bank Mini thermal energy storage
Japanese industrial project cuts equipment costs by around 30% and achieves CO₂ payback in under a year. A waste heat recovery project in Kitakyushu City, Japan, has showed how compact thermal energy storage can help industrial sites capture heat that would otherwise be lost and make it available where and when it is needed.
Led by IHI Corporation, the project uses Sunamp Central Bank Mini to capture surplus boiler heat from soap manufacturer Shabondama Soap Co., Ltd. The stored heat is transferred to neighbouring Hirota Chemical Industry Co., Ltd., where it is used within the production process to warm chemical materials. Sunamp
The project provides a practical example of how PCM thermal storage can bridge mismatches in timing and power between industrial waste heat availability and thermal demand, while creating opportunities for heat sharing between neighbouring sites.
The challenge
In a dense industrial area, the two neighbouring factories presented a common waste heat recovery challenge.
One site had useful surplus heat available from its boiler operation, while the neighbouring facility required energy to heat chemical drums before they returned to production. However, the heat source and heat demand did not necessarily occur at the same time or at the same thermal power.
The project therefore required a system capable of:
- Capturing intermittent industrial waste heat
- Storing useful thermal energy with low standing losses
- Separating heat recovery from immediate process demand
- Helping bridge timing differences between heat supply and demand
- Transferring useful heat reliably between two separate industrial sites
For designers and engineers, this is an important role for thermal energy storage: the heat source does not need to follow the process demand in real time.
A Sunamp Central Bank Mini thermal battery, using Plentigrade® P58 phase change material, was installed at the soap manufacturing facility to store recovered boiler heat.
Central Bank Mini is designed for commercial and industrial thermal energy storage. Each P58 unit can store up to 80 kWh of thermal energy and can accept suitable heat from waste heat recovery systems, boilers and heat pumps at temperatures up to 80°C.
In this application:
- Surplus boiler heat is captured through a heat exchanger
- The recovered heat charges the Central Bank Mini thermal store
- Stored thermal energy can be retained until it is required
- Heated water is transferred through approximately 70 metres of underground pipe to the neighbouring chemical facility
- The recovered heat is then used to warm chemical drums before they return to the production process.
By placing thermal storage between the heat source and the end use, the system can continue to provide useful heat even when heat recovery and process demand do not occur simultaneously.
The results
Following testing and operational modelling, IHI reported strong technical, commercial and environmental outcomes from the project:
- Around 30% lower initial equipment costs compared with pre-trial estimates
- CO₂ payback in under one year, with emissions associated with manufacture and installation offset during the first year of operation
- Longer-term operating cost savings
- Productive reuse of heat that would otherwise have been wasted.
The project demonstrates how compact thermal energy storage can make industrial waste heat recovery more practical where direct heat reuse is constrained by differences in location, timing or thermal demand.
Why this matters for industrial specifiers
Waste heat recovery is not simply a question of finding a source of heat. The available temperature, thermal power, operating profile and timing of demand all influence whether that heat can be reused effectively.
Central Bank Mini provides a thermal buffer between heat supply and demand. Heat can be captured over time and stored until a process requires it, helping project teams design around:
- Intermittent waste heat sources
- Peak process heat demands
- Timing differences between heat generation and use
- Restricted plant room space
- Integration with heat pumps, boilers and heat recovery systems
- Modular thermal storage requirements.
Central Bank Mini is also modular, allowing multiple units to be configured in series or parallel where additional thermal storage capacity is required. Its PCM-based design can be up to three times smaller than an equivalent hot water thermal store, making it particularly relevant for retrofit and space-constrained commercial and industrial projects.
Enabling heat sharing between industrial sites
The demonstration also explored the potential for Heat as a Service, where recovered thermal energy could be supplied between separate organisations rather than each business generating all of its heat independently.
IHI Corporation described Central Bank Mini's role as helping to “adjust the timing difference between heat demand and supply”, and is progressing the concept towards commercial deployment.
For industrial estates, manufacturing clusters and other sites where one process rejects heat while another requires it, thermal energy storage can therefore become an important part of wider heat recovery and heat sharing infrastructure.
Specify Central Bank Mini
Central Bank Mini (P58) is a compact PCM thermal battery for commercial and industrial applications including:
- Industrial waste heat recovery
- Process heat
- Clean-in-place (CIP) and washdown
- Pre-heating
- Space heating
- Integration with heat pumps and boilers
- Thermal load shifting
- Heat sharing between buildings or industrial processes.
Watch this explainer video on Youtube to know more about Central Bank Mini.
Download the Central Bank Mini BIM object to explore dimensions, technical data and specification information.
