Energy Efficiency Improvement and Cost Saving Opportunities for the U.S. Iron and Steel Industry An ENERGY STAR(R) Guide for Energy and Plant Managers

Abstract

Energy is an important cost factor in the U.S iron and steel industry. Energy efficiency improvement is an important way to reduce these costs and to increase predictable earnings, especially in times of high energy price volatility. There are a variety of opportunities available at individual plants in the U.S. iron and steel industry to reduce energy consumption in a cost-effective manner. This Energy Guide discusses energy efficiency practices and energy-efficient technologies that can be implemented at the component, process, facility, and organizational levels. A discussion of the structure, production trends, energy consumption, and greenhouse gas emissions of the iron and steel industry is provided along with a description of the major process technologies used within the industry. Next, a wide variety of energy efficiency measures are described. Many measure descriptions include expected savings in energy and energy-related costs, based on case study data from real-world applications in the steel and related industries worldwide. Typical measure payback periods and references to further information in the technical literature are also provided, when available. The information in this Energy Guide is intended to help energy and plant managers in the U.S. iron and steel industry reduce energy consumption and greenhouse gas emissions in a cost-effective manner while maintaining the quality of products manufactured. Further research on the economics of all measures-and on their applicability to different production practices-is needed to assess their cost effectiveness at individual plants.

Emerging Energy-efficiency and Carbon Dioxide Emissions-reduction Technologies for the Iron and Steel Industry

“…The SCS technology is currently under development. An SCS coke reactor operating in Germany was relocated to China a few years ago (Worrell et al 2010). Figure 5 shows a schematic drawing of the single-chamber system.…”

“…The following benefits are reported for SCS coking reactors compared to conventional multichamber coking reactors (Worrell et al 2010;Nashan 2007):  Reduced coking time  Improved productivity  Increased coke strength  Reduced space requirement, which increases design flexibility of the plant  Ability to use wider range of coal, particularly coals containing less volatile matter, thus yielding a higher coke output  Lower coke reactivity index values and higher coke strength after reaction values compared to those of conventional systems using similar coal  Lower capital investment costs than for conventional ovens, particularly from implementing lean oven chambers  Estimated capital investment of approximately $40 million for 100,000 t of BF coke per year; estimated cost savings of 10 $/t coke or higher  Utilization of coke oven gas as energy carrier, reducing agent for iron ore, and synthesis gas in chemical plants  Lower maintenance costs  Reduced CO 2 emissions Block Diagram or Photo: Worrell et al (2010), Nashan (2007) …”

“…The main benefit of development of a commercial technique for slag heat recovery would be the energy savings, which are estimated to be approximately 0.35 GJ/t pig iron (around 2.5 percent of BF energy use) (Worrell et al 2010). …”

“…A kilogram of plastic can replace about 0.75 kg of coke. When plastics are used, a reduction of the hot metal sulfur content is possible because plastics have a lower sulfur input than heavy oil or coke (Worrell et al 2010). …”

“…Many studies from around the world have identified sector-specific (e.g., Worrell et al 2010;AISI 2010;EPA 2010;APP 2010;EIPPCB 2010) and cross-cutting (e.g., U.S. DOE/AMO 2012) energy-efficiency technologies for the iron and steel industry that are already commercially available. However, information is limited and not easily accessible regarding emerging or advanced energy-efficiency and low-carbon technologies for the industry that have not yet been commercialized.…”