เปรียบเทียบวิธี

	สมการสภาวะ Peng-Robinson	UNIFAC
สาขาวิชา	ฟิสิกส์ประยุกต์	ฟิสิกส์ประยุกต์
ตระกูล	Process / pipeline	Process / pipeline
ปีกำเนิด	1976	1975
ผู้ริเริ่ม	Ding-Yu Peng and David Bernard Robinson	Aage Fredenslund, Russell Jones, John Prausnitz
ประเภท	Equation of state; thermodynamic property correlation	Activity coefficient model; predictive liquid-phase property method
แหล่งต้นตำรับ	Peng, D. Y., & Robinson, D. B. (1976). A new two-constant equation of state. Industrial & Engineering Chemistry Fundamentals, 15(1), 59-64.	Fredenslund, A., Jones, R. L., & Prausnitz, J. M. (1975). Group-contribution estimation of activity coefficients in nonideal liquid mixtures. AIChE Journal, 21(6), 1086-1099.
ชื่อเรียกอื่น	PR-EOS, Peng-Robinson model	UNIFAC predictive model, UNIQUAC functional-group contribution
ที่เกี่ยวข้อง	4	3
สรุป	The Peng-Robinson equation of state is a cubic model that describes the thermodynamic properties of pure fluids and mixtures. Introduced by Ding-Yu Peng and David Bernard Robinson in 1976, it improves upon earlier models (van der Waals, Redlich-Kwong) by better predicting compressibility factors and phase equilibria, especially near the critical point. It is widely used in petroleum engineering, chemical process design, and natural gas calculations.	UNIFAC (Universal Functional-group Activity Coefficient) is a predictive model for liquid-phase activity coefficients of multicomponent mixtures. Developed by Fredenslund, Jones, and Prausnitz in 1975, it decomposes molecules into functional groups and uses group interaction parameters to estimate non-ideal behavior. UNIFAC is revolutionary because it can predict phase equilibria for mixtures never experimentally measured, making it invaluable for process design and chemical engineering.