Investigation of an integrated system with industrial thermal management options for carbon emission reduction and hydrogen and ammonia production

Abstract

Abstract A new integrated energy system employing the cement slag waste heat is uniquely proposed in this study. The core focus of the proposed system is to generate clean hydrogen thermochemically and convert it into ammonia. The designed system consists of the copper–chlorine (Cu–Cl) cycle, a cryogenic air separation unit and a steam Rankine cycle while the useful commodities produced by the proposed system are hydrogen, ammonia, oxygen, hot water and electricity. A CO2 emission analysis is also conducted to calculate the emissions which can be avoided by recovering this waste heat. The Aspen Plus simulation software is utilized to model and simulate the proposed integrated system. A thermochemical water splitting process is incorporated into the system for hydrogen production. The cryogenic air separation unit is integrated in order to separate nitrogen from the air. This proposed system also reduces the environmental effects of the flue gas emitted by the cement industry. Multiple parametric studies are performed to investigate the system performance by varying operating conditions and state properties. The energy analysis is implemented on each component of the designed system. The overall energy efficiency of the system is concluded as 30.1%. The amount of CO2 emissions which can be avoided by utilizing this waste heat is 29.64 ktonne/5 years.