Process modifications to maximise energy savings in total site heat integration

A new methodology combining total site analysis with exergy analysis

“…The first case study is described by Chew et al (2014). In this case study, the authors use the plus minus principle as well as other methods that improve the utilities consumption.…”

“…To prevent large modifications that might affect utilities performance, temperature modifications are restricted to ±10 K. The objective function is modified to represent the utilities cost per MW as in Chew et al (2014), thus (24) becomes: obj = 2.5 * C VHPS + 2 * C HPS + 1.5 * C MPS + C LPS + 0.2 * C CW (26)…”

“…The TSA method was the basis for development of other methodologies and techniques used to study issues of multiple plants energy integration such as planned or sudden shutdowns and their impact (Liew et al, 2012) or process modifications to reduce the general utility size (Chew et al, 2014). In general, the TSA allows determining the energy savings, cogeneration potentials and information about the utilities needed to allow heat exchange between plants.…”

Total Site Heat Integration Considering Pressure Drops

“…The utility usage and generation are directly interpolated on the TS-PTA at the respective utilities temperatures [20]. An example of the TS-PTA is given in Table 3.…”

“…The TS energy targets are determined using the pinch-based graphical and algebraic method [20]. (e) Pressure drops determined for liquid utility systems can be used as an input to the cost optimisation in terms of higher pumping cost and the constraints in allowable ∆P.…”