Heat integration — History, recent developments and achievements

Process Integration (PI) is a powerful tool for designing and optimising processes for energy efficiency and sustainability. It has been widely extended and become both a part of most good degree studies curricula as a routine tool for advanced design and optimisation in various industries. However, sometimes its simplicity is still misunderstood. Even PI and in this contribution specifically heat integration (HI) has some potential pitfalls related to the problem formulation and data extraction. Regardless of the precision used, the results largely depend on solving the correct problem — i.e. if the formulation reflects the reality adequately and if the appropriate data have been extracted. An incorrect data extraction has been the reason for conclusions that PI did not work. When revisiting most of those problems, it becomes obvious that it was not a fault of the PI methodology, but an inexperienced user.