**5. Overall summary and recommendation**

#### **5.1 Summary**

The approach to attain energy efficiency in facility designed is incredibly important in achieving sustainable best-in-class energy efficient facility design. ADU-VDU case is presented to produce insight for developing plant level sustainable energy efficient design which may well be extended to the facility level. Since the facility operates as an integrated system of plants, units and streams, it must be understood in and of itself and it must be treated in and of itself. Research within the area of process systems

*Sustainable Energy Efficient Industrial Facility Design DOI: http://dx.doi.org/10.5772/intechopen.108829*

#### **Figure 9.**

*Future energy efficient facility design.*

engineering has led to a motivating breakthrough referred to as process integration. This breakthrough has expanded the influence of engineering design to methodically and insightfully address systems of multiple plants, units and streams employing a consistent basis of fundamental concepts of chemical and systems engineering. Process integration is defined as a holistic approach to design and operation that emphasizes the unity of the process. Thus, unifying all processes specified all design intents are met is that the way to achieve sustainable energy efficient design. All design aims are addressed well except Retrofit-ability, as an example Reliability, Accessibility and Maintainability is fulfilled by RAM Study while Safety and Operability requirements are accomplished by HAZOP Study. As, in its entire lifetime, an industrial facility undergoes various retrofit subjected to changes that features but not limited to process disturbances, uncertain feedstock conditions, product demand, throughput increase, feedstock changes, improve performance etc., it has to be considered as a criterion for the new design. In summary, it is stated that, the retrofitting of a plant may be needed numerous times, in its lifespan, the most effective way to approach it's through sustainable energy efficient facility design because it will fulfill most of retrofits objectives.
