Process Economics and Environmental Impacts of Process Intensification in the Petrochemicals, Fine Chemicals and Pharmaceuticals Industries - Process Intensification for Green Chemistry - page 363

Table 14.2 Petrochemicals capital cost elements and their relative contributions (data
derived from [7], Table 25-50 fluids processing).

Element Factor %

Process equipment delivery (free on board) 1 22-18

Process equipment installation 0.27-0.47 6-9

Piping 0.66-1.20 15-22

Steel and concrete for the structure 0.13 3-2

Electrical and instruments 0.09-0.11 2-2

Building and site preparation 0.92-1.19 21-22

Auxiliaries 0.70 16-13

Contractor fees 0.21 5-4

Contingencies 0.42 10-8

Total 4.40-5.43 100

Capital Cost. Table 14.2 lists the major capital cost elements of petrochemical processes.
The cost estimation method starts from the process equipment cost, obtained from the
vendors. All other cost is then calculated using the factor values inTable 14.2. Thismethod is
of course only valid for conventional equipment.
If, for instance, a microreactor were to be chosen which had a higher equipment cost than
the conventional reactor, but a much lower volume and weight, then this cost calculation
method would result in a higher cost for all other elements, but it is clear that the steel and
concrete cost would in reality not go up, but rather down, and all other costs would stay the
same. To avoid this mistake it is better to take the same value for all cost elements outside
the microreactor as for the conventional reactor. The steel and concrete cost is a small
fraction of the total, so this simple method is justified.
Table 14.2 implies that reducing the amount of equipment reduces all other capital cost.
Therefore, reducing the amount of equipment using PI, as in reactive distillation (RD), is a
very effective way of reducing total cost.

CapitalCost andScale-up. Thecapital cost of thepetrochemical process typically increases
with process production capacity according to the power law [7]:

capacity 0 : 6 Capital cost ¼ constant (14.1)

This implies that the cost per ton of product decreases with increasing capacity:

capacity 0 : 4 Capital cost = ton product ¼ constant (14.2)

Other costs, suchas labour, increaseeven lesswithcapacity,while transport costs are constant
per ton of feedstock and product. For this reason, petrochemical processes are designed for
very large capacities.

Return on Investment. Accurate ROI calculations are complicated as they must take into
account the capital expenditure over the installation time and the additional costs and low