Chem. Eng. Thermodynamics(TKK-2137)

14/15 Semester 3

Instructor: Rama OktavianEmail: rama.oktavian86@gmail.comOffice Hr.: M.13-15, Tu. 13-15, W. 13-15, Th. 13-15, F. 09-11

Outlines

1. Thermodynamic terms review 1. Thermodynamic terms review

2. Thermodynamic properties 2. Thermodynamic properties

3. 1st law thermodynamics review 3. 1st law thermodynamics review

Thermodynamic terms

What is thermodynamic?

the study of the transformations of energy

enables us to discuss all matters quantitatively and to make useful predictions

e.g: The release of energy can be used to provide heat when a fuel burns in a furnace, to produce mechanical work when a fuel burns in an engine, and to generate electrical work when a chemical reaction pumps electrons through a circuit

Thermodynamic terms

What is thermodynamic?

Thermodynamics is the science of energy. A sound understanding of thermodynamics will allow you to determine how energy is controlled and converted in devices.

Thermodynamics is at the heart of every aspect of – design of an engine. – design of respirator.– And many more devices.

----- “Engineering Thermodynamics”, J.B. Jones, R.E. Dugan (Prentice Hall, 1996)

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Thermodynamic terms

Thermodynamic terms

A thermodynamic system is that part of the physical universethe properties of which are under investigation

A system is isolated when the boundary prevents any interaction with the surroundings

A system is called open when mass passes across the boundary, closed when no mass passes the boundary

Thermodynamic terms

Thermodynamic terms

Properties of a System - physical attributes that are perceived by the senses, or are made perceptible by certain experimental methods of investigation

1. non-measurable, as the kinds of substances composing a system and the states of aggregation of its parts

2. measurable, as pressure and volume, to which a numerical value can be assigned by a direct or indirect comparison with a standard

Thermodynamic terms

State of a System. A system is in a definite state when each of its properties has a definite value.

Change in State, Path, Cycle, Process. Let a system undergo a change in its state from a specified initial to a specified final state

The change in state is completely defined when the initial and the final states are specified

The path of the change in state is defined by giving the initial state, the sequence of intermediate states arranged in the order traversed by the system, and the final state

Thermodynamic Systems

State of a system – Determined by the state of matters

constituting the system.– Gas / liquid / solid state or the coexistence of

more than one phases.– Single component / multi-components.– Equilibrium / nonequilibrium.

Process– A system changes its state from one to

another state.– Initial state / path / final state.– Reversible / irreversible processes.

e.g., density, T, P, etc.

Thermodynamic Systems

The state of a system:– Determined by properties of matters within a

system, e.g., T, P, composition, density, etc. Some properties are interrelated, e.g., T, P, mass,

and V. The equation that correlates T, P, M, V is called the

equation of state (EOS). The ideal gas law (an EOS) was identified while

studying low-density gases. An universal temperature scale, the absolute

temperature scale, was defined.

– Can be specified by specifying two independent properties and masses of matters of the system – related to degree of freedom

Thermodynamic terms

A process is the method of operation by means of which a change in state is effected

State Variable, . . . . A state variable is one that has a definite value when the state of a system is specified . . . .

Path Variable,… Variable that do depend on path

Thermodynamic properties

Properties of matters:– Intensive / Extensive properties, mass-

dependent or not. Intensive properties: T, P, density, molar

volume, refractive index, etc. Extensive properties: mass, volume, etc.

Properties whose quantity is proportional to the amount (mass) of matter are called extrinsic properties, e.g., volume, gravity force, energy, etc.

Properties whose quantity is independent of the amount (mass) of matter are called intrinsic properties, e.g., density, T, P, color, etc

1st law thermodynamics

• Thermodynamics was then developed to study energy… The first law deals with energy interchanges. How efficiently can energy be converted from one form to another? Carnot answered this question, leading to the second law of thermodynamics …

• When the first and the second laws are combined they lead to relations that tell how much work is available in a given situation, a concept called availability, or exergy.

1st law thermodynamics

Properties of matters:– Energy content of matters:

– Other properties having the same unit as energy Enthalpy, Free energy, etc.

KineticEnergy

InternalEnergy

PotentialEnergy

NOTE: Heat and Work are energies exchanged between a system and its surrounding, not properties associated with matters.

Total Energyof matters

Processsimulation

ThermodynamicProperty• Activity coefficient (Wilson, NRTL, UNIQUAC, UNIFAC)

• EoS: virial, vdW, RK, SRK, PR, Gen. Corrr.)

TP

MeasurementsPublisheddata

30% effort untuk physical properties(Chen and Mathias, AIChE, 48 (2002) 194-200)

Q, W, Equilibrium conditions

Physical & Chemical Processes

DIPPR, DECHEMA, Journal2

Thermodynamics: Is it important??