Heat integration optimization

Partially vaporized feed reverses these effects. For a given separation, the feed conditions can be optimized. No attempt should be made to do this at this stage in the design, since heat integration is likely to change the optimal setting later in the design. It is usually adequate to set the feed to saturated liquid conditions. This tends to equalize the vapor rate below and above the feed. 

It must be emphasized that it is not worth expending any effort optimizing pressure, feed condition, or reflux ratio until the overall heat-integration picture has been established. These parameters very often change later in the design. 

No attempt should be made to optimize pressure, reflux ratio, or feed condition of distillation in the early stages of design. The optimal values almost certainly will change later once heat integration with the overall process is considered. 

The thermal profile through the reactor will in most circumstances be carefully optimized to maximize selectivity, extend catalyst life, etc. Because of this, direct heat integration with other process streams is almost never carried out. The heat transfer to or from the reactor is instead usually carried out by a heat transfer intermediate. For example, in exothermic reactions, cooling might occur by boiling water to raise steam, which, in turn, can be used to heat cold streams elsewhere in the process. 

For a given separation, the feed condition can be optimized. No attempt should be made to do this in the early stages of an overall design, since heat integration is likely to... 

Yee TF, Grossmann IE and Kravanja Z (1990) Simultaneous Optimization Models for Heat Integration -1. Area and Energy Targeting of Modeling of Multi-stream Exchangers, Comp Chem Eng, 14 1151. 

HEAT-INTEGRATED DISTILLATION SEQUENCES BASED ON THE OPTIMIZATION OF A SUPERSTRUCTURE... 

Papageorgiou, L.G., Shah, N., Pantelides, C.C., 1994. Optimal scheduling of heat-integrated multipurpose plants. Ind. Eng. Chem. Res., 33 3168-3186 Peneva, K., Ivanov, B., Bancheva, N., 1992. Heat integration of batch vessels at fixed time interval. 

A mathematical approach for optimization of energy use in heat integrated multipurpose batch plants has been presented and tested in a case study. The results have shown that heat integration with heat storage considerations can result in energy savings of more than 75%, compared to standalone operation that relies solely on... 

Duran, M. A. and I. E. Grossmann. Simultaneous Optimization and Heat Integration of Chemical Processes. AIChE J 32 123-138 (1986). 

Yee, T. F. I. E. Grossmann and Z. Kravanja. Simultaneous Optimization Models for Heat Integration—I. Area and Energy Targeting and Modeling of Multistream Exchangers. Comput Chem Eng 14 1165-1183 (1990). 

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