Step 5. Establish process options and constraints.
With a firm product slate, work may now commence to map processing routes
that will achieve the product objective. This will include very rough plant
configurations irrespective of cost or other constraints that will fulfill a
processing route. This step should end with the elimination of the more obvious
undesirable routes, for example, those routes which contain very small process
units or those that contain unit processes that have undesirable by-products. This
step should provide five or six reasonable process options for further study.
Step 6. Commence screening studies.
The purpose of this item is to reduce the number of possible options to two or at
the most three process configurations that appear most economically attractive.
To arrive at the selected options, those alternates arrived at in step 5 are allocated
capital and operating costs. The capital costs in this case are very rough
estimates arrived at by applying factors to the installed cost for similar processes.
Details of this technique in cost estimating are given later in this chapter under
the discussion of section “Capital Cost Estimates.” Licensors are usually
requested to participate in the development of these cost items in the case of
their proprietary processes. The operating costs for nonproprietary processes are
also factored from similar processes. With these cost data in place, an incremental payout time is calculated for each option. The option with the lowest
capital cost is used as a base case and the others compared against it. Details of
this calculation are given later in this chapter. The two (or three) options with the
lowest positive incremental payout time against the base case are selected for
further study.
Step 7. Prepare data for a more accurate cost estimate.
The credibility of any economic study depends to a large extent on the accuracy
of the data used in predicting the various cost items. The principal cost item will
be the capital cost of the processes to be installed and/or revamped. The next step
in the study therefore is for the development engineer to provide basic engineering for a “semi-definitive” capital cost estimate to be prepared. (Very often, the
refining company may solicit third-party engineering contractors to undertake
this step.) Should the project proceed from study stage to installation, this
estimate may be used as the first project budget estimate for project control.
Details of this type of estimate are given later in this chapter. Briefly, for this
estimate, development engineers (and/or third-party engineering contractors)
will:
• Prepare process flow sheets (complete with mass balances).
• Prepare preliminary mechanical flow sheets (complete with line and instrument sizes and specifications).
• Initiate all equipment data sheets sufficient for obtaining manufacturers’ firm
prices.
• Review and select manufacturers’ offers for equipment.
• Using selected manufacturers’ equipment data, prepare a preliminary utility
balance and size by factoring new or expanded utility facilities.
• Factor additional offsite facilities as required.
702
D.S.J. Jones and P.R. Pujado ´
With a firm product slate, work may now commence to map processing routes
that will achieve the product objective. This will include very rough plant
configurations irrespective of cost or other constraints that will fulfill a
processing route. This step should end with the elimination of the more obvious
undesirable routes, for example, those routes which contain very small process
units or those that contain unit processes that have undesirable by-products. This
step should provide five or six reasonable process options for further study.
Step 6. Commence screening studies.
The purpose of this item is to reduce the number of possible options to two or at
the most three process configurations that appear most economically attractive.
To arrive at the selected options, those alternates arrived at in step 5 are allocated
capital and operating costs. The capital costs in this case are very rough
estimates arrived at by applying factors to the installed cost for similar processes.
Details of this technique in cost estimating are given later in this chapter under
the discussion of section “Capital Cost Estimates.” Licensors are usually
requested to participate in the development of these cost items in the case of
their proprietary processes. The operating costs for nonproprietary processes are
also factored from similar processes. With these cost data in place, an incremental payout time is calculated for each option. The option with the lowest
capital cost is used as a base case and the others compared against it. Details of
this calculation are given later in this chapter. The two (or three) options with the
lowest positive incremental payout time against the base case are selected for
further study.
Step 7. Prepare data for a more accurate cost estimate.
The credibility of any economic study depends to a large extent on the accuracy
of the data used in predicting the various cost items. The principal cost item will
be the capital cost of the processes to be installed and/or revamped. The next step
in the study therefore is for the development engineer to provide basic engineering for a “semi-definitive” capital cost estimate to be prepared. (Very often, the
refining company may solicit third-party engineering contractors to undertake
this step.) Should the project proceed from study stage to installation, this
estimate may be used as the first project budget estimate for project control.
Details of this type of estimate are given later in this chapter. Briefly, for this
estimate, development engineers (and/or third-party engineering contractors)
will:
• Prepare process flow sheets (complete with mass balances).
• Prepare preliminary mechanical flow sheets (complete with line and instrument sizes and specifications).
• Initiate all equipment data sheets sufficient for obtaining manufacturers’ firm
prices.
• Review and select manufacturers’ offers for equipment.
• Using selected manufacturers’ equipment data, prepare a preliminary utility
balance and size by factoring new or expanded utility facilities.
• Factor additional offsite facilities as required.
702
D.S.J. Jones and P.R. Pujado ´