Thermodynamics meets economics

Cost optimization for complex energy-conversion systems (e.g., refineries or integrated gasification-combined-cycle power plants) or energy-intensive chemical plants is usually expensive and requires knowledge of engineering, science, and business. The goal of optimization is to find the values of the system variables (the temperatures, pressures, and chemical composition of flow streams, equipment size, materials, etc.) that minimize the cost of the final products. In many cases a rigorous cost optimization for a complex energy system is not possible because some of the cost functions that are needed to express the capital cost of a component as a function of thermodynamic variables (temperatures, pressures, etc.) are either unavailable or inaccurate. But even in cases in which all the information is available and acceptably accurate, it is expensive and time-consuming to formulate and solve an optimization problem with an extremely large number of equations, constraints, and highly interdependent variables.