An ArcelorMittal steel plant in South Africa cut R90 million ($9.7 million) from its energy bill through an efficiency improvement project.
The project was the product of a energy management strategy that was launched in 2010, Dhesan Moodley, the general manager of the steel and mining giant’s Saldanha works (pictured) in South Africa’s Western Cape province, told ESI-Africa.com.
Initially, any potential savings were identified through an energy audit and an examination of its existing project list. The plant then initiated an ISO 50001-compliant energy management system that cut its energy use by 6.6 percent in a year, according to the interview.
Moodley says that the installation of a number of variable speed drive technologies delivered “greater savings that expected” and that a waste heat recovery project enacted at Saldanha’s roller hearth furnace has completely replaced a diesel heater at the facility’s air separation plant. The company has also installed some optimization projects at the water pump plant that required no capital expenditure.
The next project that Moodley is excited about is a contract that will replace the plant’s use of liquid petroleum gas in certain places with biogas from a bio-digester.
Lessons Moodley learned from the project include the need to assign resources if you are “really serious” about saving energy and the importance of staff training on efficiency issues and behavior.
Moodley also says that introducing energy savings is relatively easy when compared to sustaining them. This is especially true if continued savings rely on altering human behavior, Moodley says. The implementation of a system such as ISO 50001 can be invaluable to entrench and sustain such savings, he says.
In December, ArcelorMittal Indiana Harbor, the largest steel mill in North America commissioned a $63 million energy recovery project. The 504-boiler project recycles blast furnace gas to produce high-pressure steam used to power its steel mill. Prior to the commissioning 22 percent, or 46 bn cubic feet, of blast furnace gas per year was wasted when it was flared into the atmosphere.