(82e) Process Intensification Based on Modular Decomposition to Improve the Sustainability of Chemical Processes

Process intensification through hybrid equipment combining unit operations has the potential to improve sustainability and decarbonize chemical processes by reducing energy and emissions while improving economics. One of the critical steps in intensifying a process is to systematically select which unit operations need to be combined to develop an intensified process. This work presents a novel methodology to guide such intensification using a graph representation and modularity analysis for the decomposition of a process flowsheet such that the process structure itself helps us to identify strongly related process units that have the potential to be combined into hybrid units or other forms of intensification. The methodology aims to identify and analyze intensified alternatives using process graph modularity and the Fire and Explosion Damage Index (FEDI) as criteria to carry out intensification. The first stage consists of developing or reproducing a conventional design through process simulation and obtaining the necessary information to carry out the analysis. In the second stage, safety is analyzed with the FEDI indicator, which is then used as a weighting criterion in the modularity analysis. The intensification of the process is carried out in the third stage, intensifying the process by combining process units that form a process module and generating new alternatives. The fourth stage is used to analyze the alternatives and see if the new designs generate more modules. Process design alternatives are evaluated and compared in terms of energy demand, economic and environmental indicators. Finally, the best alternative is selected. The methodology is illustrated by two case studies, the first involves the separation of an ethanol-butanol-water mixture. The results show that the safest design is the alternative that was developed using this approach and incorporates two columns with a dividing wall and correlates with a high modularity of 0.607. Energy usage is reduced by 25.8% compared to the non-intensified design, which had lower modularity (0.385). An empirically guided design was proposed as Alternative 2 which led to a modularity of 0.533, but only 10% energy savings and no improvement in FEDI. The second case study presents the intensification of a biojet fuel production process. In the intensified process energy utility costs were reduced by 70%, while ROI increased by 20%. In environmental terms, the global warming potential was reduced by 30%. The FEDI value drops from 123 to 105, indicating an inherently safer process. This demonstrates that modularity-driven intensification strengthens integration between process units while improving both the safety and energy efficiency of a process. As such, the approach has wide potential application to guide the intensification of other chemical processes.