Chemical Engineering Thermodynamics

A course in engineering thermodynamics is required of students in all engineering disciplines. In addition, chemical engineering students take, generally in the first semester of the third (junior) year, a specialized thermodynamics course called Chemical Engineering Thermodynamics. Thermodynamics is the engineering science that deals with the interconversion between work and energy. The concept of equilibrium is integral to thermodynamics, and the essence of Chemical Engineering Thermodynamics is the study of equilibrium phenomena in chemical systems. Equilibrium can be understood to be the state of a system from which no change is expected; that is, the system is in a stable state. It follows that any system not at equilibrium will have the tendency to move toward equilibrium. The driving force for any process is the departure from equilibrium.

Chemical Engineering Thermodynamics helps students define equilibrium in terms of thermodynamic quantities, such as enthalpy, entropy, free energy, and so on, and relate these thermodynamic quantities to measurable system properties, such as pressure, temperature, volume, and composition [13]. Students learn about the changes in thermodynamic quantities associated with various chemical processes and how to quantify these changes from the volumetric behavior of substances. Volumetric behavior refers to the pressure-volume-temperature relationship for the substance. The ideal gas law is the simplest equation describing the volumetric behavior. Most substances, as they are not ideal gases, require more complex equations, and students learn about nonideal behavior and equations that describe this behavior.

Students learn to apply the laws of thermodynamics to chemical systems—pure substances and mixtures, single phase and multiphase, reacting and nonreacting. Figure 3.14 provides an overview of the course.

Figure 3.14 Overview of the Chemical Engineering Thermodynamics course.

Concepts learned in Chemical Engineering Thermodynamics are applied in the advanced courses, particularly separation processes and kinetics, and provide the theoretical foundation for process and equipment design.