Page 196 - Analysis, Synthesis and Design of Chemical Processes, Third Edition

Example 7.8.

Example 7.8

Determine the capital cost for a major expansion to a fluid processing plant that has a total purchased
equipment cost of $6,800,000.
Capital Costs = ($6,800,000)(4.74) = $32,232,000

This estimating technique is insensitive to changes in process configuration, especially between processes
in the same broad categories shown in Table 7.7. It cannot accurately account for the common problems
of special materials of construction and high operating pressures. A number of alternative techniques are
available. All require more detailed calculations using specific price information for the individual
units/equipment.

7.3.2 Module Costing Technique

The equipment module costing technique is a common technique to estimate the cost of a new chemical
plant. It is generally accepted as the best for making preliminary cost estimates and is used extensively in
this text. This approach, introduced by Guthrie [9, 10] in the late 1960s and early 1970s, forms the basis
of many of the equipment module techniques in use today. This costing technique relates all costs back to
the purchased cost of equipment evaluated for some base conditions. Deviations from these base
conditions are handled by using multiplying factors that depend on the following:
1. The specific equipment type
2. The specific system pressure
3. The specific materials of construction

The material provided in the next section is based upon information in Guthrie [9, 10], Ulrich [5], and
Navarrete [11]. The reader is encouraged to review these references for further information.

Equation 7.6 is used to calculate the bare module cost for each piece of equipment. The bare module cost
is the sum of the direct and indirect costs shown in Table 7.6.

(7.6)

where C BM = bare module equipment cost: direct and indirect costs for each unit

F BM = bare module cost factor: multiplication factor to account for the items in Table 7.6 plus the
specific materials of construction and operating pressure

= purchased cost for base conditions: equipment made of the most common material, usually
carbon steel and operating at near ambient pressures

Because of the importance of this cost estimating technique, it is described below in detail.