A joint exergy analysis/exergetic resilience approach for evaluation of suspension PVC production with VCM recovery

• Despite having a high energy consumption, the suspension method has a high exergy efficiency of 79%. • The exergy losses are mostly in form of unavoidable losses with the VCM recovery section having the highest of the process stages. • The drying section presented the most avoidable losses of the process due to wastes stream from the cyclone. • The sensibility analysis showed that the valorization of wastes can improve the exergy performance of the process up to 84% • It is recommended the use of energy integration techniques and changing equipment to utilize energy streams to the fullest extent possible. Suspension process is the main method of production of PVC, it is characterized by an intensive consumption of energy. Due to the ongoing climate crisis, the study of energy utilization of chemical processes has become relevant as a step to achieving sustainable operations. Therefore, an exergetic analysis is proposed to study the energy management of the PVC production process by suspension. The process was modelled using simulation software which allows the quantification of the extended mass and energy balances of the process and the thermodynamic properties of pure substances and mixtures. From this information chemical and physical exergies were obtained; exergy parameters were calculated per stage and for the whole process. The analysis showed that the process has efficient energy management with an efficiency of 79.6%, showing that most of the exergy inputs remain in the product stream, with irreversibilities of 236.798 MJ/h of mostly unavoidable losses (80%). It was found that the drying and VCM recovery stages presented poor performance, the drying stage had the highest irreversibilities (75,618 MJ/h) associated with avoidable losses (wastes) with 46,488 MJ/h. The VCM recovery section presented the lowest exergy efficiency (84%) due to mainly unavoidable losses (45,268 MJ/h). Furthermore, a sensitivity analysis was performed, valorizing the process waste, resulting in an increase in efficiency up to 84% and a reduction in irreversibilities to 56%. Also, improving the recovery section would increase global efficiency by up to 95%. However, the unavoidable losses are the main source of exergy destruction of the process; reducing them has the potential to increase efficiency significantly, so it is recommended to expand the analysis to study the service streams (heating, fuel, and refrigerants) together with energy integration.