Integrated Cost Targeting and Process Design

10 INTEGRATED COST TARGETING AND PROCESS DESIGN 9.10.1 Conventional Design Approach 

FIGURE 9.19. A systematic design procedure embedding energy optimization. 

The concept of targeting sounds very powerful, but there are challenges in application. One challenge is the selection of energy costs to be used as the basis—including 

Another key factor for successful cost targeting is capital cost estimation. Capital costs for heat recovery systems include costs for heat exchangers, heaters, and coolers. Improper estimates of capital cost can lead to suboptimal trade-offs between capital and utility costs. One important aspect is good estimates of heat transfer coefficients for individual process streams since heat transfer coefficients determine the size and surface area of heat exchangers. A second consideration for accurate capital costs is realistic cost calculation for process furnaces and cooling towers in the targeting phase of work— these are much more expensive than heat exchangers. 

but certainly not least, a design task schedule needs to be developed carefully to minimize the time required to develop a process design. Allocation of design activities should be proper such that the energy optimization work is done and completed in parallel with other process design work thus, no extra project time is required. 

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