**3. Case Studies**

In this work, two case studies are used to demonstrate the exergy footprint evaluation of process systems. The scalability of the concepts and their applicability to problems from different domains are tested using two case studies.

The first case study deals with a single process of recovery of a chemical component. It involves the evaluation of the exergy profit of acetic acid from waste streams. Two processes involving acetic acid (AA) as the input and output—i.e., methanol carbonylation and vinyl acetate monomer (VAM) production—are chosen. The exergy profit is determined by taking the exergy needed for the processes and the exergy contents of the outlet streams into account.

The second case study considers a larger-scale, distributed system involving the potential treatment processes of Municipal Solid Waste (MSW), which is the output from private households. The exergy profit of the MSW stream is evaluated, considering the exergy requirement for the treatment processes, such as landfill and recycling, as well as the useful exergy content of the secondary products. For the exergy calculations, the specification of the reference point is 25 ◦C and 1 atm = 101.325 kPa.
