The circular economy is an industrial system designed for recovery and regeneration to replace “end of life” with “recovery" in order to turn waste into resources and thereby achieve waste reduction. By constantly implementing the circular economy, we implement water conservation and drainage reduction through improvement programs to reclaim and recycle valuable water resources for reuse and set the annual water conservation target at “1%". The actual conservation in 2021 was 4.26%. The boundary of water resource and effluent management is the Kaohsiung Plant, with data coverage of 100%.
In terms of water stress distributions, based on the water stress by country in the ‘Aqueduct Water Risk Atlas’ published by the World Resources Institute (WRI), the water stress of Taiwan falls at the low to medium level, with water stress at 10-20%.
According to the 2020 water resources statistics published in the Water Resources Agency Register Statistical Report, MOEA, the water consumption of Kaohsiung City was 280,439 Ml, including 94,101 Ml of water for domestic use or public use, 85,677 Ml of water for industrial use, 80,177 Ml of water for agricultural use, and 20,485 Ml of water for other uses. The 2020 total water withdrawal of Kaohsiung Plant was 1,029.036 Ml, accounting for about 0.4% of Kaohsiung City’s total water consumption. USI withdraws water mainly from tap water supplied by the Pingding Waterworks and Cheng Ching Lake Waterworks for product production, equipment cooling, boiler, domestic use of employees, and other uses. Compared to 2020, water withdrawal in 2021 reduced by about 31 Ml to 998.098 Ml.
★ Water conservation and reclamation
Following the rising water demand, escalating climate change impact, and expanding sustainability pressure, we keep a constant track on water shortages and endeavor to reduce water consumption or enhance water reclamation in response. When the water shortage was severe in Kaohsiung during April-May 2021, the Kaohsiung City Government rationed water supply for industrial use by 7% at phase I and 11% at phase II. In response to the government’s industrial water rationing policy and promote water conservation and consumption control, we advocated the cessation of using tap water for irrigation, washing building exterior walls, cleaning ditches, washing cars, and taking shower, which would consume more water. We also enhanced leakage inspection of pipelines and control valves to save water across the plant.
Water reclamation program |
Effectiveness |
Enhancing the recycling rate of water resources |
We have improved the steam condensate recovery system. After the completion and operation of the Kaohsiung Plant’s new steam boiler, the condensate reclaimed from steam can be reused in the new boiler for re-use. The water reclaimed is approximately 47,520 MT/year.
Calculation: The project was completed in 2016. After field tests, we found that the reclamation volume is 6 MT/hour. Based on 330 days a year, the annual reclamation volume is 47,520 MT.
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Recycling spillage water reclaimed from pellet cutting |
Spillage water reclaimed from pellet cutting is first transported to the sedimentation tank. Then, it is pumped into the reclaimed water treatment plant before being further transported to the cooling tower for re-use to reduce tap water consumption and process effluents. The water reclaimed is approximately 27,720 MT/year.
Calculation: The project was completed in 2016. After field tests, we found that the reclamation volume of the system is 14 MT/batch. Based on six batches a day and 330 days a year, the annual reclamation volume is 27,720 MT.
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Continuous monitoring and reclamation of effluents |
Continuous monitoring of the in-house effluent quality to enhance effluent treatment and response capacity and ensure that effluents comply with the discharge standards. After reclaiming by the system, effluents are treated before being transported to the cooling tower for re-use to reduce tap water consumption and process effluents.
Calculation: Based on the readings of pumps on-site, the total wastewater reclamation in 2021 was 10,986 MT.
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Detention basin and storm water reclamation channel |
Pipelines will be installed from the existing detention basin and storm water reclamation channel to the cooling tower. After filtering by the storm water separator next to the cooling tower, storm water will be re-used by the cooling tower. The water reclamation in 2021 is about 15,914 MT.
Calculation: The project was completed in 2017 and started operation in 2018. The plant catchment area is 3,500 m2, the tank site dike area is 3,300 m2, Kaohsiung’s annual rainfall in 2021 was 2,600 mm. Based on a reclamation rate of 90%, the estimated water reclamation is about 15,914 MT/year.
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MRT Steam Condensate Recovery |
Steam condensate is recovered for reuse in the boiler to reduce tap water consumption. The project annual recovery is 17,500 MT.
Calculation: Steam condensate recovery at 2.2 MT/hour. The number of workdays is 330 days/year. The annual recovery is thus 2.2×24×330≒17,500 (MT/year).
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Note: The estimated volume of reclaimed and recycled water in 2021 was 119,640 MT; the total water withdrawal was 998,098 MT; the volume of reclaimed and recycled water was 12% of the total water intake.
★ Water Efficiency Management System
In 2021 we implemented the ISO 46001:2019 Water Efficiency Management System and completed system certification in February 2022. By inventorying the current status and ways of water consumption across the plant, through identifying, planning, managing, and improving the risks and opportunities of water with systematic water consumption management, and thereby optimizing water demand management, we effectively achieved the goals of water conservation and discharge reduction to enhance water efficiency and reduce water costs.
In 2022, we will enhance wastewater system management and optimize operation to reduce wastewater discharge and increase wastewater reclamation up to 12,000 MT (projected). We will also implement process improvement and reduce MRT steam use to save water up to 2,880 MT/year (projected).
★ Water as a shared resource
In 2021 we planned the firewater connection project with the plants (Grand Pacific Petrochemical Corporation) in the nearby Dashe Industrial Park. Besides dispatching water to support firefighting through water as a shared resource, this also strengthened the emergency response capability. Currently, Grand Pacific Petrochemical Corporation has connected firewater with TSRC Corporation in a firewater storage tank of about 4,500 m3. Currently, the effective capacity of our firewater storage tank is 4,297 m3. After the completion of the connection project at the end of 2022, the total volume of firewater as a shared resource will be about 8,797 m3.