2.3.2. Capital Cost

It is empirically observed that all capital cost components, such as construction cost, pump cost, and equipment cost, are correlated with the plant capacity, size of the main equipment, or other design parameters, in the power-law form [20]:

$$\text{cost} = k(\text{size})^n \tag{25}$$

Instead of directly relating the capital cost of the membrane to capacity, Sethi and Wiesner [7] proposed an approach for predicting capital costs of membrane processes. In this approach, the capital cost is divided into several major categories and the capital cost for each category is developed to improve the accuracy. Membrane system costs generally consist of the costs of pumps and other manufactured equipment. The correlation of each category to the plant capacity is discussed in detail as follows.
