Page 277 - Chemical engineering design

252
CHEMICAL ENGINEERING
instrumentation costs for each piece of equipment are costed separately. Detailed costing
is only justified if the cost data available are reliable and the design has been taken to the
point where all the cost items can be identified and included.
Typical factors for the components of the capital cost are given in Table 6.1. These
can be used to make an approximate estimate of capital cost using equipment cost data
published in the literature.
In addition to the direct cost of the purchase and installation of equipment, the capital
cost of a project will include the indirect costs listed below. These can be estimated as a
function of the direct costs.
Indirect costs
1. Design and engineering costs, which cover the cost of design and the cost of
“engineering” the plant: purchasing, procurement and construction supervision.
Typically 20 per cent to 30 per cent of the direct capital costs.
2. Contractor’s fees, if a contractor is employed his fees (profit) would be added to the
total capital cost and would range from 5 per cent to 10 per cent of the direct costs.
3. Contingency allowance, this is an allowance built into the capital cost estimate to
cover for unforeseen circumstances (labour disputes, design errors, adverse weather).
Typically 5 per cent to 10 per cent of the direct costs.

The indirect cost factors are included in Table 6.1.
The capital cost required for the provision of utilities and other plant services will
depend on whether a new (green field) site is being developed, or if the plant is to be
built on an existing site and will make use of some of the existing facilities. The term

Table 6.1. Typical factors for estimation of project fixed capital cost
Process type
Item Fluids Fluids Solids
solids
1. Major equipment, total purchase
cost PCE PCE PCE
f 1 Equipment erection 0.4 0.45 0.50
f 2 Piping 0.70 0.45 0.20
f 3 Instrumentation 0.20 0.15 0.10
f 4 Electrical 0.10 0.10 0.10
f 5 Buildings, process 0.15 0.10 0.05
Ł
f 6 Utilities 0.50 0.45 0.25
Ł f 7 Storages 0.15 0.20 0.25
Ł
f 8 Site development 0.05 0.05 0.05
Ł f 9 Ancillary buildings 0.15 0.20 0.30
2. Total physical plant cost (PPC)
PPC D PCE (1 C f 1 C ÐÐÐ C f 9 )
D PCE ð 3.40 3.15 2.80
f 10 Design and Engineering 0.30 0.25 0.20
f 11 Contractor’s fee 0.05 0.05 0.05
f 12 Contingency 0.10 0.10 0.10
Fixed capital D PPC (1 C f 10 C f 11 C f 12 )
D PPC ð 1.45 1.40 1.35
Ł Omitted for minor extensions or additions to existing sites.