ORIGINAL PAPER Life cycle assessment and optimization of an iron making system with a combined cycle power plant: a case study from China Ting Li 1 • Pedro M. Castro 2 • Zhimin Lv 1 Received: 8 May 2016 / Accepted: 1 November 2016 Ó Springer-Verlag Berlin Heidelberg 2016 Abstract In the steel industry, the iron making system deals with large quantities of materials and energy and so it can play a critical role in reducing emissions and produc- tion costs. More specifically, excess by-product gases should be used for electricity generation; otherwise, they lead to pollution. A life cycle analysis is performed to compare the environmental impact of an iron making system with a combined cycle power plant (CCPP), to a system producing the same amount of electricity in a coal power plant. The results for a Chinese steel plant show a 33% reduction in the energy conservation and emission reduction potential for the CCPP system, which is thus more environmentally friendly. A mathematical program- ming formulation is then proposed for optimal scheduling. It incorporates key technological constraints and is sensi- tive to hourly changing electricity prices. The outcome is a 19% increase in revenue from electricity sales compared to a schedule that does not dynamically adjust to the price profile. The results also show that emissions from by-pro- duct gases can be avoided completely. The paper ends with a sensitivity analysis to evaluate the impact of changes in product demand, gas storage and CCPP capacity, and emission cost. Keywords Steel industry  Iron making system  Combined cycle power plant  Life cycle analysis  Emission cost  Mixed-integer linear programming Introduction The steel and iron industry in China accounts for nearly 10% of greenhouse gas emissions and energy consumption (Zeng et al. 2009) and so it is a major focus of national environmental protection policies (Ma et al. 2015). The iron making system (IMS) which includes coke, sinter and blast furnace production consumes more than 70% of the energy and materials required by the steel industry (Chen et al. 2014). Due to the consumption of a large amount of coal and the generation of large volumes of coke oven gas (COG) and blast furnace gas (BFG), coke ovens and blast furnaces are two major sources of carbon dioxide emissions during the production of molten iron (Carvalho Pinto et al. 2016). Therefore, the iron making system plays a vital role in reducing greenhouse gas emissions and energy consumption. Current IMS research aims to increase the throughput of molten iron and to reduce emissions. An active carbon recycling energy system reduced the CO 2 emissions to the atmosphere by using the CO 2 produced in the iron making system to regenerate CO by the electrolysis process, using the energy from the high-temperature gas-cooled reactor (Dipu et al. 2012). Qi et al. (2015) developed a method for hot transferring and charging coke, sinter and pellet into the blast furnaces with a gas of low carbon density and rich in oxygen and hydrogen. There are also studies dealing with the prediction of COG and BFG gas generation and consumption to better schedule the distribution and oper- ation of gas holders and increase overall gas utilization. & Zhimin Lv lvzhimin@nercar.ustb.edu.cn 1 National Engineering Research Center for Advanced Rolling, University of Science and Technology Beijing, Beijing 100083, China 2 Centro de Matema ´tica Aplicac ¸o ˜es Fundamentais e Investigac ¸a ˜o Operacional, Faculdade de Cie ˆncias, Universidade de Lisboa, 1749-016 Lisbon, Portugal 123 Clean Techn Environ Policy DOI 10.1007/s10098-016-1306-9