Pinch analysis of crude distillation unit using the HINT software and
comparison with nonlinear programming technique
Abstract
The effectiveness of HINT is first verified by the application to a case
study investigated for minimum area target, and then applied to a crude
distillation unit (CDU) after obtaining a satisfactory solution which
was within 1 percent when compared with existing solution for minimum
area target. The HINT package accomplished the maximum heat recovery
between the hot streams and the cold streams and later identified the
utility required for the heat balance in the heat exchanger networks
(HENs). Pinch analysis of the CDU plant showed that both hot and cold
utilities are still needed after the maximum energy recovery between all
the hot streams and all the cold streams present in the HENs
synthesized. The total hot utility required was found to be 4.99 x 108
kJ/hr while that of cold utility was 5.08 x 108 kJ/hr. The ∆Tmin that
gives the minimum total annual cost was found to be 2.95K and the
corresponding total annualized cost was $4.88 million/yr. The findings
also revealed that HINT is capable of returning solutions that are
comparable with those of mathematical based techniques such as the
nonlinear programming (NLP) technique used as a basis for comparison.