Techno-Economic Evaluation of Waste Heat Recovery Systems for Industrial Decarbonization

Abstract

Abstract. The decarbonization of energy-intensive industries (i.e., steel and iron, cement, aluminum, and glass) is critical for the effective reduction of CO2 emissions, which is necessary due to the continually increasing energy consumption. The industrial sector itself generates approximately 28% of global CO2 emissions. Elimination of CO2 emissions can be done via direct approach (i.e., alternative fuel or energy source) and indirect approach (i.e., utilization of waste heat). In this paper, the steelmaking process is investigated as a potential waste heat source. The steelmaking process has sources of waste heat where the waste heat can be utilized with temperatures between 473 and 1573 K based on the process step and type of furnace (i.e., Blast furnace, Basic oxygen furnace (BOF), Electric arc furnace). The waste heat can be utilized by all potential power cycles as a bottoming cycle. However, due to the large temperature range, potential retrofitting, and limited footprint, a supercritical CO2 (sCO2) waste heat recovery system can be an ideal candidate for utilizing waste heat in the steelmaking processes. The paper is focused on the optimization of potential waste heat recovery systems based on sCO2 power cycle for a steel plant with several electric arc furnaces (EAF). Several sCO2 cycle layouts have been investigated to meet the requirements. Results show higher performance of the sCO2 cycle and potential retrofitting into the current steel plants. The sCO2 power cycles can reach cycle efficiencies above 40% and provide approximately 800 kWel with approximately Levelized cost of electricity (LCOE) of 0.065 $/kWhel.