Effective energy management is showing significant cost savings at South Africa’s largest steel producer, ArcelorMittal’s Western Cape plant in Saldahna, says the National Cleaner Production Centre of South Africa (NCPC-SA).
Energy savings were achieved at the Saldanha plant with the help of NCPC-SA, which challenged and changed some of the plants standard operational practices, instead of focusing on major capital investment.
ArcelorMittal Saldanha Works in the Western Cape, which is a steel producer mainly for the export market, was recently praised by donor partners of the Industrial Energy Efficiency Improvement Project (IEE Project) for the significant energy efficiency improvements that it has achieved through its participation in the project.
The plant served as a pilot site for the IEE Project, which is managed by the NCPC-SA. The NCPC-SA is hosted by the Council for Scientific and Industrial Research (CSIR) on behalf of the Department of Trade and Industry (DTI).
Interventions to manage energy usage at the plant required an investment of R500 000, but led to gross financial savings of more than R89.6-million within the first year (2011).
By the end of June 2013, the value of energy savings reached R176-million and it is estimated that the savings realised will account for R362-million by 2016.
Examples of interventions include reducing the use of fans and pumps, maintaining the temperature of the water-cooling system, preventing the unnecessary use of burners, and reducing the consumption of liquid petroleum gas (LPG).
“Results have been reached with a relatively small investment; however, I realise the complexities around implementation of the energy-saving methods as well as how skilful the management and workforce must be to achieve these objectives,” Swiss ambassador to South Africa Christian Meuwly said during a recent donor partners visit to the plant.
The IEE Project was initiated in South Africa after rolling blackouts in 2008 exposed the country’s acute shortage of electricity. The project is a collaboration between the Department of Energy, the DTI, the Swiss Secretariat for Economic Affairs as well as the UK Department for International Development, and is implemented by the United Nations Industrial Development Organisation and the NCPC-SA.
During the visit, DTI green industries chief director Gerhard Fourie said the project is important in light of rapid increases in the cost of energy, which have been prevalent over past years, as well as the pressure on the South African economy to reduce its carbon footprint.
“The interventions to reduce the energy requirement on the power grid make this industry more competitive, and make a large contribution to the reduction in our greenhouse-gas emissions,” says Fourie.
He adds that these large industries play a major part in the local economy, and highlights that South Africa has to create a structural change over time, where manufacturing with beneficiation can occur more frequently. “It is important that big industries remain competitive and sustainable.”
Western Cape NCPC-SA senior project manager Alf Hartzenburg highlighted the importance of having top management on board during such initiatives.
“An energy project starts with the commitment from the top down, and is not something that can be implemented at middle or lower management level. Top management commitment provides resources in terms of time and funding,” says Hartzenburg.
The NCPC-SA say that they were fortunate to have the commitment of ArcelorMittal Saldanha Works GM Dhesan Moodley, who had the foresight to support this initiative, which has enabled the organisation to unlock available opportunities.
ArcelorMittal joined a capacity-building programme offered by the IEE Project in January 2011. The company’s engineers were trained by international experts on energy-management systems, as well as on improvements of pumps, compressed air, fan and motors systems.
Training and technical support enabled the plant to implement an energy-management system in its ironmaking, steelmaking and milling departments, which account for 70% of the plant’s energy consumption.
Previously, cooling fans in the melt-shop were left running even during limited or nonproduction times, which occurred 30% of the time. It was found that only one of the two fans was needed to run during these times. No capital investment was needed and the cost savings accounted for R262 000 in 2011.
The water-cooling system also consumed significant energy. This system was improved by maintaining the temperature of the water supply as close as possible to summer temperatures of 40 °C throughout the year, thereby reducing the need for air-cooled heat exchangers.
When the average air temperature was 16 °C in winter, it was found that it was possible to turn off 35% of exchangers. The overall cost savings amounted to more than R1.37-million in 2011.
During the ironmaking, steelmaking and casting operations, molten metal is transported between stations in ladles. The burners that heat the ladles are fired up by gas. The staff believed the burners needed to run continuously even between operations, as they did not trust the burner start-up mechanisms. In this case, a behavioral and cultural change was needed among the ladle stations’ operating staff.
After being briefed and understanding the reasons behind the improvements, the staff agreed to switch the burners off when not required, and R250 000 was saved in 2011.
The most significant improvement at the works has been with the overall reduction of LPG consumption, which was driven by a severe gas shortage. The plant reduced its consumption by 26% within three months (by the end of December 2011), and this resulted in savings of R52-million. This consumption was reduced by another 30% by the end of 2012.
Further, repairing a hole in the liquid iron-producing corex melter improved the reliability of production and reduced the number of unplanned stoppages.
Other interventions, such as the repairing of leaks in the compressed air system, use of chemical energy during winter and further ‘switching-off’ awareness raising during standing times, added to the energy savings at the plant, and accounted for around R37-million of the R89-million saved in 2011.
The NCPC-SA has been hosted by the CSIR for the past ten years on behalf of the DTI. Through the IEE Project, it has facilitated the implementation of energy-management systems and energy-systems improvements in several large and small companies in energy-intensive sectors such as the metal and automotive industries.
The NCPC-SA says that ArcelorMittal is the single biggest success story of the IEE Project since its inception in 2010. To date, participating companies have noticed energy savings of over 270 MWh, which translates into a cost saving of R229-million and carbon emission reductions of almost 255 000 t.
Meanwhile, more than 2 000 professionals have been equipped to implement energy-efficiency measures in the industry through the IEE Project and the NCPC-SA capacity building programme.
The NCPC-SA also runs an internship programme aimed at enhancing the employability of engineering graduates, who are given intensive training in identifying and implementing resource efficiency and cleaner production interventions.