Comparative Analysis of an Expandable Modular Plant and a Stick-Built TiO₂ Plant

Expandable modular plants (EMPs) can be the future of the chemical industry, especially in emerging markets. Using the relative position of points on alternative NPV-time curves from the period of 10-20 years, we compare the economics of an expandable modular TiO₂ plant with that of a large-scale TiO₂ plant constructed fully on site (stick-built) and present scenarios where the expandable modular approach is economically favorable over the stick-built approach. To simplify the assessment of economic viability between constructing an EMP and a stick-built plant, we introduce a measure known as the flexibility feasibility ratio-a certain ratio of unit installed capacity in an EMP to the nameplate capacity of a stick-built plant at which the NPVs are equal at all points on alternative NPV-time curves. We determine that a flexibility feasibility ratio of 0.25 is suitable to install an expandable modular TiO₂ plant in Nigeria, relatively.