Chemical Engineering Thermodynamics

Chemical Engineering Thermodynamics (ECE3253)

Introduction

(Week 1)

B. Eng (Hons) Chemical Engineering

PowerPoint® Slides

by PS Yap

2© I-Station Solutions Sdn Bhd18/04/2023Last Updated:

Chapter Overview

• The use of chemical engineering thermodynamics

• The equilibrium state


Learning Objectives

1. To introduce the basic properties of chemical

engineering thermodynamics

2. To introduce the concepts of equilibrium


Learning Outcomes

Students will be able to:

1. Define the basic terminology of thermodynamics, such

as internal energy, potential energy, kinetic energy,

system, and phase

2. Understand the general concepts of equilibrium, which

is very important in the application of thermodynamics

in chemical engineering


Introduction

Internal energy – The energy of a substance associated with the motions, interactions, and bonding of its constituent molecules

External energy – Associated with the velocity and location of its centre of mass, which is of primary interest in mechanics

System – The region under study, which may be a specified volume in space or a quantity of matter

Surrounding – The rest of the universe

Phase – The state of agglomeration of the system, that is whether it is a gas, liquid, or solid


Introduction – cont’d

Adiabatic system – A well-insulated system in which there are no heat flows in or out.

Closed system – A system in which there are no mass flows in or out.

Isolated system – A system that is closed to the flow of mass and energy in the form of work flows and heat flows (i.e. is adiabatic)

Open/Steady-flow system – A system in which flows of mass, heat, and work may be present but in such a way the system properties do not change over time

Cyclic process – A process that follows a periodic path so that the system has the same properties at any point in the cycle as it did at that point in any preceding or succeding cycle


A System of Units


The Equilibrium State

Steady states – Also known as time-invariant states.

Natural flows – Flows that arise naturally and drive the system to equilibrium

Forced flows – Flows imposed on the system by its surrounding


The Equilibrium State (cont’d)

Stable system – The system returns to its initial equilibrium states

Unstable system – The system does not return to its initial state

Figure 1.3-1 Blocks in states (a) and (b) are stable to small mechanical disturbances; the delicately balanced block in state (c) is not


Pressure, Temperature, and Equilibrium

etemperaturT

constantgasR

volumemolarV

pressure absolute P

:where

273.15 C)T( (K) T

RTVP


Heat, Work, and the Conservation of Energy

Heat – Transfer of energy as a result of only a temperature difference

Work – Energy transfer by any mechanism that involves mechanical motion of or across the system boundaries


Heat, Work, and the Conservation of Energy (cont’d)


Intensive and Extensive Variables

Intensive variables – Size-independent property (e.g. pressure and temperature)

Extensive variables – Variable dependent on the size or amount of the system (e.g. mass, volume and total energy)


Equations of State

2)(1.6uationV)......EqP(U,P

V)(P,UU

P)(T,UU

1)(1.6tion).....EquaV(T,UU

)VP(T,P

^^

^^

^^^

^


References

S.I. Sandler (2006). Chemical, Biochemical, and Engineering Thermodynamics. John Wiley.

Chemical Engineering Thermodynamics

Documents

Transcript of Chemical Engineering Thermodynamics