Introduction to Chemical Engineering Thermodynamics-I

1. Introduction to Chemical Engineering Thermodynamics-I Ashfaq M Ansery ChE Deptt, BUET

2. History • The name was coined in 1849 by Lord Kelvin by combining Greek words for heat (thermos) and power (dynamos) • The science of thermodynamics was born in the middle of 19th century to describe the operation of steam engine and their limit of operation Chemical Engineering Thermodynamics-I

3. Thermodynamics • Thermodynamics is the study of the inter-relation between heat, work and internal energy of a system Chemical Engineering Thermodynamics-I

4. Example Chemical Engineering Thermodynamics-I

5. So…… Thermodynamics is • the science of heat and work and related properties • the basic science that deals with energy • the study of energy movements Chemical Engineering Thermodynamics-I

6. Why study thermodynamics? • Design of equipment such as • steam turbines • refrigerators and heat pumps • compressors • boilers • condensers • cooling towers and heat exchangers Chemical Engineering Thermodynamics-I

7. Methods of Studying • Two methods of studying thermodynamics • Classical thermodynamics • Statistical thermodynamics Chemical Engineering Thermodynamics-I

8. Classical thermodynamics • Macroscopic viewpoint towards mater • It requires no hypothesis about the detail structure of matter on the atomic scale, nor it is necessary to assume that molecules exist • Its conclusions are quite general Chemical Engineering Thermodynamics-I

9. Statistical Thermodynamics • Based on average behavior of large groups of individual particles • The microscopic approach is more elaborate and is rather involved Chemical Engineering Thermodynamics-I

10. Scope of Thermodynamics • The basis of thermodynamics is ‘experimental observation’ • These findings have formalized into certain basic laws • Zeroth law • First law of thermodynamics • Second law of thermodynamics • Third law of thermodynamics Chemical Engineering Thermodynamics-I

11. Scope of Thermodynamics • The first law of thermodynamics is simply an expression of the conservation energy principle • The 2nd law of thermodynamics asserts that energy has quality as well as quantity; and actual process occur in the direction of decreasing quality of energy Chemical Engineering Thermodynamics-I

12. Scope of Thermodynamics • Thermodynamics deals with equilibrium positions • Thermodynamic considerations do not establish the ratesof physical or chemical processes • Thermodynamics, a macroscopic-property formulation, cannot reveal the microscopic (molecular) mechanisms of physical or chemical processes Chemical Engineering Thermodynamics-I

13. Concluding Remark • If everything is so simple, why does thermodynamics have the reputation of being hard? Chemical Engineering Thermodynamics-I

14. Concluding Remark • It is full of hard words and signs and numbers, not very entertaining or understandable looking ... (quoted in Levenspiel, p. xi) • The difficulty comes from making precise descriptions of phenomena and in developing a mathematical framework that allows us to cultivate an understanding of the Laws Chemical Engineering Thermodynamics-I

15. Text Book • Introduction to CHEMICAL ENGINEERING THERMODYNAMICS, sixth edition by J. M. Smith, H.C. Van Ness, M.M. Abbott Chemical Engineering Thermodynamics-I