A hybrid poly-generation system for power and hydrogen production by thermal recovery from waste streams in a steel plant: Techno-economic analysis

Abstract

The steel industry stands as a prominent energy-intensive sector characterized by significant heat losses. In this research, a novel configuration of a poly-generation hybrid system, specifically tailored to explore the viable prospects of waste heat recovery within a steel manufacturing facility, is introduced. The proposed system comprises a steam Rankine cycle (SRC), a Kalina cycle, two organic Rankine cycles (ORC), and a proton exchange membrane (PEM) electrolyzer, collectively facilitating the recuperation of an impressive 262 MW of dissipated energy from the steel plant. A technical and economic assessment is conducted to evaluate the performance of the system. The proposed system demonstrates an energy efficiency of 25.76%, resulting in the concurrent production of power, heat, and hydrogen at rates of 48.39, 29.42 MW, and 8.12 tons/day, respectively. The system exhibits an exergy efficiency of 57.46%, with an exergy destruction magnitude of approximately 45 MW. It is revealed that the SRC cycle represents the primary contributor to the energy destruction portfolio of the proposed system, accounting for an impressive 67.83%. Furthermore, a comprehensive economic analysis has been conducted, revealing an initial capital cost of 36.6 MM$ for the implementation of this system. The revenue generated from the sale of electricity and hydrogen amounts to 3.6 and 3.8 MM$ per annum, respectively. Based on these financial considerations, the estimated return period for the investment is projected to be approximately 7 years.