2015 Volume 55 Issue 2 Pages 373-380
Japanese steelworks achieve the world’s highest energy efficiency. However, approaches that seek intra-steelworks optimization alone have limitations when planning further energy conservation. It is thus necessary to establish a system that effectively utilizes energy at the societal level.
This study is proposed a hybrid steelworks having functionality that combines steel manufacturing and energy supply, focusing on improving the energy utilization of by-product gas. As the results, the typical hybrid steelworks is able to supply society with low-cost electric power without increasing energy consumption through the use of combined high-efficiency GTCC with the promotions of energy conservation in steelworks such as CO2 and N2 separation in blast furnace gas. Moreover, if the technology of this hybrid steelworks is applied to all steelworks in Japan (84 million t-steel/year blast furnace crude steel), the power generation potential is more than 38 billion kWh/year which is equivalent to 4.0% of gross domestic power demand. Furthermore, a CO2 reduction of 33 million t-CO2/year nationally can be expected; this effect is equivalent to a 23% reduction in steelworks CO2 emissions.