(35a) Use of Heat Pumps as Part of an Overall Steam Management Strategy

Use of Heat Pumps as Part of an Overall Steam Management Strategy

A large integrated producer of specialty C4 chemicals and derivatives recently completed an analysis of heat integration applications at its facility located along the Houston ship channel. This study was undertaken as part of a larger effort to ensure the long term operability and reliability of the sites steam and power systems.

A major objective of this study was to examine ways to eliminate or mitigate steam consumption by investigating heat integration options. One application that showed significant potential for steam savings was in the area of separating close boiling C4 isomers.

This paper illustrates how a heat pump may be applied to the distillation of isobutylene from isobutane to substantially reduce and/or eliminate reboiler steam demand.   Three different heat pump options for this separation are evaluated and screened to arrive at the optimum design. An economic analysis for the optimum design is also presented.

Finally, the impact of the heat pump on unit as well as overall site steam and power demand is evaluated in terms of existing and anticipated operability, reliability, and emissions impact in light of future projects as well as planned expansion of steam generation facilities.