A JOINT project by Globalfoundries Singapore and Edwards Technologies Singapore for combustion chamber replacement abatement units has received Honourable Mention in the Best Practices category at the EENP Awards 2016.
The project involved a redesign of the existing abatement units to reduce LPG consumption. Thermal abatement units are used to break down process gases for safe disposal into the atmosphere. To reduce LPG consumption, the two companies working together retrofitted 35 thermal abatement units by halving the size of the combustion chamber and reducing the nozzle size. To ensure that the gas residence time and destruction efficiency remained unchanged, the total abatement capacity was kept constant by increasing the length of the weir.
The project yielded good results as the annual LPG consumption was reduced by 31 per cent, from 613 tonnes to 420 tonnes. This translated to an annual energy cost saving of US$200,000 and an annual carbon abatement of about 640 tonnes.
Globalfoundries is a leading full-service semiconductor design, development, fabrication and innovation company with locations across the globe.
Globalfoundries Singapore is the largest semiconductor foundry in Singapore with a staff strength of more than 6,000 here.
"Energy use reduction is always a part of Globalfoundries' priorities. Hence engineering module studied the energy cost allocation and identified LPG as one of the major contributor. Engineering module also identified thermal processing units with different combustion chamber sizes (24 inch/12 inch) consume different amounts of LPG. The opportunity was carefully studied. We then discussed with our strategic partner, Edwards Technologies, to work on the proposal together to reduce the LPG consumption," says Gu Zhi Min, GM and VP of Fab Management.
Besides big facility infrastructural projects for promoting energy efficiency such as more efficient chillers, the company has also worked on individual equipment chillers. It subsequently modified the chiller and its compressor such that instead of letting them run continuously, the chillers are only operated when needed. This is another success story that has resulted in electrical saving of 1.1 MKw per year with 0.6 years ROI (return on investment). Besides electrical cost saving, the operating life of the chiller compressor is now longer due to the shorter working periods as it no longer needs to work continuously.
Globalfoundries Singapore's energy management team consists of a certified Singapore Certified Energy Manager (SCEM), a Certified Energy Manager (AEE-CEM) and various domain experts from facilities and fab operations.
The work on energy efficiency (EE) started many years back with several key EE projects including upgrade of facilities chillers, thermal energy storage tanks, upgrading of gas farms and installation of kWh meters in most of the company's plants.
The team has developed an electricity consumption monitoring system that is used every day to keep track of the data from hundreds of meters installed.
"The main objective of the system is to identify abnormal electricity usage pattern and focus the various system owners to find the exact root cause of abnormal usage and bring usage back to baseline. This system has proven to be very effective in detecting system consumption drifts and allows us to reduce the potential impact every time as well as optimising the consumption by various systems," says Mr Gu.
Going forward, the company plans to promote the energy efficiency culture by encouraging more of its staff to do more energy efficient projects by showcasing to employees the EENP Award given to it to encourage ideas and support them on the ideas. The central engineering group is driving and promoting energy efficiency. Currently, it is working on solar energy with some vendors.
Kirel Tang, applications knowledge management director at Edwards Technologies Singapore, says that for the project with Globalfoundries, the company took a fundamental look at the system design and invested resources to enable the abatement units to be more energy efficient.
"An analysis of the performance characteristics of our gas-fired abatement units showed that a key abatement efficiency parameter is the residence time of the process gas species in the combustion zone, not the rate of fuel supply to the combustor. By optimising the residence time of gas species in the hot reaction zone, Edwards has been able to reduce the total fuel input while maintaining the same high abatement efficiency for those gas species which are typically pyrophoric, toxic, corrosive or GHG (greenhouse) in nature.
"Therefore, a straightforward upgrade of the combustion chamber with an extended reaction zone and optimised fuel gas supply allows the abatement system to be operated on the same process with up to 50 per cent less fuel gas consumption."
Edwards, part of the Atlas Copco group, is a leading manufacturer of sophisticated vacuum products and abatement systems and a leading provider of related value-added services for the manufacture of microelectronics devices, including silicon and compound semiconductors, flat panel displays, solar manufacturing and LEDs.
"At Edwards, we strive to be the environmental leader in the field of vacuum pump and abatement by applying technology, products and services to benefit the environment for future generations. Besides adopting all the relevant environmental standards like ISO14001 in our environmental management system, and establishing green goals to achieve our aims, Edwards is proud to claim that over our product's life cycle, we are greenhouse gas or carbon equivalent negative," says Dr Tang.
On getting an honourable mention for best practices at this year's EENP Awards, Dr Tang notes: "This award is recognition of Edwards' initiatives in the area of controlling emissions and promoting energy efficiency. It validates the focus and efforts that we have put in so far, and confirms we are progressing in the right direction, and is therefore very important to us.
"We are satisfied that our vision for reducing all emissions and enhancing energy efficiency in sub-fab operations has been recognised by the industry. It also strongly suggests that awareness within the industry is increasing, and Edwards is proud to be an environmentally aware company within this industry, with a readiness to face challenges and collaborate with our customers and partners going ahead, so as to create a brighter and better future for the world."