TNB Grid's SF6 Gas Recycling and Reconditioning Centre, a trailblazer in Southeast Asia's environmental efforts, redefines SF6 gas management. SF6, a potent greenhouse gas crucial for insulating electrical equipment like Gas Insulated Switchgear (GIS) and Circuit Breakers (CBs), poses a significant environmental challenge. With the highest Global Warming Potential (GWP) of approximately 23,500 and an atmospheric lifetime of around 3,200 years, SF6 necessitates a solution to reduce reliance on virgin gas and minimise its environmental impact.
Our rising SF6 consumption and the high cost of returning waste to its origin countries for incineration further emphasise the need for a solution. Incineration, the most common method, raises concerns due to potential greenhouse gas emissions during the process. Returning waste to origin countries like Germany, South Korea, and Australia is expensive, costing RM11.6/kg with an additional surcharge of RM232 for every 40kg bottle. Launched in October 2021, the centre tackles this challenge head-on, minimising environmental impact by embracing a circular economy approach and paving the way for a more sustainable future.
A Circular Economy Approach: Reduce, Reuse, Recycle
The SF6 Gas Recycling and Reconditioning Centre embodies a circular economy approach, focusing on the 3R principles: Reduce, Reuse, and Recycle. This minimises reliance on virgin gas and reduces environmental impact.
Reduce
By effectively recycling SF6 gas, we minimise the need to purchase new gas cylinders, directly reducing overall SF6 gas acquisition.
Reuse
The recycled gas is meticulously reconditioned to meet the required standards, enabling its reuse within our operations for GIS and CB maintenance, extending the lifespan of valuable resources.
Recycle
The centre employs a meticulous four-stage SF6 gas handling process, with the first two stages (Recovery and Recycling) dedicated to collecting and reprocessing the gas for reuse.
The SF6 Gas Handling Process
The centre utilises a meticulous four-stage process to manage SF6 gas effectively, employing specialised equipment for each stage. Here's a table summarising the process:
| Stage | Equipment | Function |
|---|---|---|
1. Recovery |
Service Carts |
Collect and store SF6 gas extracted from electrical equipment during maintenance activities. |
2. Recycling |
Mini SF6 Gas Handling Unit (No. 1) Pre-Filter Unit SF6 Gas Handling Unit (No. 2) |
Used for main storage pumping of received gas (liquid form) and storing it as a gaseous form inside the storage tank (with additional function of pump back storage from the measurement test set). Filters moisture and gaseous products from the input gas before pumping it into the SF6 Gas Handling Unit (No. 2). The main GHU pumps mixed gas from the Mixed Gas Storage Tank or from the Mini GHU to the Main Gaseous Storage Tank. It can also clean mixed gas bottles using N2 and a vacuum pump. |
3. Treatment |
SF6 Gas Separating Plant |
This stage is used for higher purity requirements. It utilises low-pressure, high-pressure, and buffer tanks operating at low temperatures to remove impurities through a recycling process, resulting in high technical grade SF6. However, this process also generates a small percentage (10-20%) of waste gas. |
4. Disposal (Minimal) |
N/A |
Any remaining unusable SF6 gas undergoes a safe and environmentally friendly disposal process that adheres to strict regulations. This minimises waste and ensures responsible environmental practices. |
As of April 2024, the centre has processed a total of 11,114.83kg of SF6, contributing to cost savings of RM500,167.35 year-to-date (YTD) from January 2022 to April 2024. This represents an impressive 86% of the targeted cost avoidance for the facility.
To maximise the environmental and economic benefits, TNB has also stopped procuring new SF6 gas in bulk. By implementing a closed-loop system, the centre plans to incorporate the use of recycled SF6 gas for GIS rehabilitation, repair and refurbishment works.
Financial and Environmental Benefits
The TNB SF6 Gas Recycling and Reconditioning Centre offers a win-win situation. It reduces TNB Grid's environmental footprint by promoting SF6 gas reuse and minimising reliance on virgin gas, aligning with TNB's Sustainability Pathway 2050 and supporting national climate change mitigation efforts. Additionally, TNB Grid estimates potential savings of at least RM0.6 million annually.
Beyond internal use, there is a potential regional service. We envision the SF6 Gas Recycling and Reconditioning Centre becoming a key player in regional sustainability efforts. By offering our services to external parties, the Centre can benefits companies and utilities across Southeast Asia:
Support Large Power Consumers
Companies with industrial facilities that utilise SF6-insulated equipment can benefit from our recycling and reconditioning services, reducing their environmental footprint and contributing to regional sustainability goals.
Empower Neighbouring Utilities
We have the potential to partner with utilities in Southeast Asia, providing them with access to this eco-friendly solution for SF6 gas management. This can contribute to a collective reduction in the region's greenhouse gas emissions and support regional climate change mitigation efforts.
Through TNB's SF6 Gas Recycling and Reconditioning Centre, we promote circular economy and reduce the impact to environment.