Utility-Process Interface Optimization

A step-by-step procedure was obtained in optimizing the utility and process by working
inwards of onion model diagram. The process plantused in the case study is the palm oil
refinery, whilethe utility is the steamgeneration withturbo generator. Utility system was
the first part that beingoptimized since the source of energy is coming from this system.
From the optimization of utility, the marginal steam pricing plot was constructed to
visualize the scope of saving as a result of steam saving at the process site. The energy
saving of the process was obtained by working outthe difference of the existing to the
minimum heating requirement. The amount of steam saving then used to determine the
scope of saving by referring to the marginal steam pricing plot which is at
$32,326.44/year. A retrofitting of the heat exchanger network was made and the
estimated capital cost of installing new heat exchanger, covering the needed area was
about $123,266.24. The payback period for investing the new heat exchanger with the
scope saving obtained is about 4 years.