Process synthesis and simulation of amine solvent regeneration in natural gas sweetening units using heat pump assisted configurations

For natural gas sweetening, amine based chemical absorption is the most used process. However, large energy requirements in the regeneration of the amine solvent makes this process energy intensive. The concept of heat pump assisted distillation has been known to reduce energy requirements in distillation processes. In this work, we study, simulate and analyze four different configurations for the regeneration of amine employing the concept of heat pump. The studied configurations are based on the concepts of Mechanical Vapor Recompression (MVR) and Self-Heat Recuperation (SHR). The configurations were simulated using Aspen HYSYS software. The configurations were mainly analyzed by comparing their overall energy consumption, overall cooling energy and operational costs. The developed configurations were also compared with the conventional regeneration unit design. The results show that the best obtained configuration uses both MVR and SHR based design of heat pump. The SHR aspect related to further preheating of the feed stream. This resulted in savings in the overall energy consumption, cooling energy and operational costs were 10.11%, 10.92% and 8.28% (savings of about 41,000 $/yr) as compared to a conventional regeneration unit design for this configuration.