Thermodynamic Properties Involving Derivatives Using the Peng-Robinson Equation of State


  • R.M. Pratt The National University of Malaysia


Entry in the "Class and Home Problems" series.

Mathematical manipulation of derivatives is a topic found in nearly every thermodynamics textbook.  Most students spend considerable time during the first few weeks of their thermodynamics course learning to express these derivatives in terms of measurable quantities. Rarely, however, are they given an opportunity to calculate numerical values for these derivatives.  This article discusses calculation of such properties using the Peng-Robinson equation of state, and application is made to a hydrocarbon mixture.  Calculation of the three partial derivatives in P, V, and T is first made, then determination of the real fluid heat capacities, and finally, application is made to two useful thermodynamic properties-the sonic velocity and the Joule-Thompson coefficient.

Author Biography

R.M. Pratt, The National University of Malaysia

Ronald M. Pratt is a lecturer in the engineering department at the National University of Malaysia. He obtained his BS in mathematics and in chemical engineering at the Colorado School of Mines, his MS in mathematics at the Fuxin Mining Institute in Liaoning Province, China, and his PhD in chemical engineering at the Colorado School of Mines. Research interests involve molecular dynamics and fractal modeling.






Class and Home Problems