Energy, environmental and economic analysis of the integration of high temperature heat pumps into amine regeneration process

This paper presents a numerical investigation of the integration of a high temperature heat pump into an amine regeneration process, with the aim of enhancing energy efficiency and reducing environmental impact (i.e. CO2 emissions) via the electrification of steam supply. Several system configurations are systematically explored, involving different heat pump architectures and working fluids. The architectures considered include a simple configuration based on a standard reverse cycle and one employing mechanical recompression of steam. For refrigerant selection, a set of candidates working fluids is extracted from the Refprop 10.0 database by filtering them based on critical temperature, normal boiling point, and Global Warming Potential. For each combination of system architecture and working fluid, a thermodynamic optimization of the heat pump working cycle conditions is carried out using a Particle Swarm Optimization algorithm. This approach enables the identification of optimal design thermodynamic parameters while ensuring compliance with a set of thermodynamic and technical constraints. The result of this phase is the identification of the most suitable refrigerant for each configuration. Following the thermodynamic analysis, a techno-economic and environmental assessment is performed, comparing the performance of the proposed heat pump integration with that of a conventional combustion boiler-based heat supply system. The results demonstrate that, under the specific constraints of the case study, the integration of a high-temperature heat pump can lead to equivalent primary energy savings in the range 31.6 to 36.6%, reductions in CO2 emissions from 26.8 to 32.0%, and OPEX saving is within 2.16M€/y to 2.71 M€/y, resulting in simplified payback between time between 0.87 years and 4.00 years. Overall, the high-temperature heat pump emerges as a key enabling technology for the transition toward more sustainable industrial thermal systems.