Complete process plants: (3) - WATER TREATMENT
15 Jan 2000
This, the third in Costimator's series on the costs of complete process plants (not to be confused with the concurrent series on individual items of plant equipment), is devoted to plants for the treatment of waste water, water quality improvements, and sea water desalination.
Water is required worldwide, both for industrial and domestic use, so these plants are clearly ubiquitous. Although the information here should therefore be particularly helpful, it should be borne in mind that the data quoted can only be used for budget purposes.
Moreover, the size and type of plant is governed by feed and product qualities and volumes, the possible combinations of which are legion. The correlations presented here - in Table 3 and Figure 3 - must therefore be used with caution and regarded very much as a `broad brush' approach.
As usual, for the costs of complete process plants we give, the base date is January 1996. In the correlations, cost is in £ and capacity in m3/h. Of the five correlations in Table 3, two of them - multistage flash distillation and flocculation, clarification, filtration and chlorination - are three or so orders of magnitude greater than the others. This is due to the type of feed and the purpose of the product. All correlations fitted the data reasonably well, although equation 3e was the least satisfactory: also the exponents tend to support the two-thirds power law.
The next issue to be focused on complete process plants will concentrate on those for industrial gases.
{{Table 3: Key and correlations to Figure 3
Curve Process and general Correlation Equationnumber application number
1 Carbon adsorption: waste Cost = 58.1(Capacity)0.63 3a water treatment and water quality improvement
2 Multistage flash distillation Cost = 68000(Capacity)0.87 3b (MSF): seawater desalination
3 Reverse osmosis (RO): saline Cost = 21.7(Capacity)0.8 3c water purification and desalination
4 Demineralisation: boiler feed Cost = 21.3(Capacity)0.65 3d water treatment and similar
5 Flocculation, clarification, Cost = 37300(Capacity)0.64 3e filtration and chlorination: large scale domestic water production}}
Figure 3: Costs of water treatment plant as functions of output
