EL25C02 Mass Transfer – Semester IV – ChemElec – R-2025

Subject Code & Name: EL25C02 – Mass Transfer

Regulation: R-2025

Semester: IV (Fourth Semester)

Branch: B. Tech. Chemical and Electrochemical Engineering (ChemElec)

Credits / L-T-P: 3 Credits | L-T-P: 3-0-0

Course Objectives

• To impart knowledge on the mechanisms of mass transfer, understand various mass transfer operations, perform material balances in unit operations, solve engineering problems related to separation processes, and select appropriate design parameters for mass transfer equipment.

Full Unit-wise Syllabus

Unit I – Molecular Diffusion

Introduction to mass transfer operations; Molecular diffusion in gases, liquids and solids; diffusivity measurement and prediction; multi- component diffusion.

Activities: Numerical problems on diffusion coefficients

Unit II – Convective Transfer and Interphase Mass Transfer

Eddy diffusion, concept of mass transfer coefficients, theories of mass transfer, different transport analogies, application of correlations for mass transfer coefficients, inter phase mass transfer, relationship between individual and overall mass transfer coefficients.

Activities: Problem-solving on mass transfer coefficients; application of empirical correlations.

Unit III – Absorption

Gas Absorption and Stripping – Equilibrium; material balance; limiting gas-liquid ratio; tray tower absorber - calculation of number of theoretical stages, tray efficiency, tower diameter; determination of height of packing using HTU and NTU calculations.

Activities: Stage-wise calculations; design problems on absorption columns.

Unit IV – Distillation

Vapour liquid equilibria - Raoult’s law, Principle of distillation - flash distillation, differential distillation, steam distillation, multistage continuous rectification, Number of ideal stages by Mc.Cabe - Thiele method, Total reflux, minimum reflux ratio, optimum reflux ratio.

Activities: Graphical construction of McCabe–Thiele diagrams; numerical problems on reflux ratio and stages.

Unit V – Liquid

Liquid extraction - solvent characteristics-equilibrium stage wise contact calculations for single stage extraction, multi-stage cross current extraction, multi- stage counter current operation. Solid liquid equilibria: Equilibrium diagram for leaching, single stage leaching, multi stage continuous cross current and counter current leaching, stage calculations, stage efficiency.

Activities: Ternary diagram analysis; numerical problems on extraction and leaching operations.

Course Outcomes (COs)

• CO1: Mapping Apply molecular diffusion concepts and mass transfer mechanisms in gases, liquids, and solids.
• CO2: Analyze convective and interphase mass transfer processes using transport correlations and mass transfer coefficients.
• CO3: Evaluate gas absorption and stripping operations using stage-wise and HTU–NTU methods.
• CO4: Design distillation systems and determine stage requirements using equilibrium concepts and the McCabe–Thiele method.
• CO5: Create separation and purification schemes using liquid–liquid extraction and leaching principles for industrial applications.

Assessment Pattern (Quick Note)

• Weightage: Continuous Assessment 40% | End Semester Examinations 60%
• Internal methodology: Assignments (20%), Application-oriented problem solving (20%), Solving competitive exam -type questions (20%), Internal Examinations (40%)

Source: Official Anna University – B. Tech. Chemical and Electrochemical Engineering R-2025 Syllabus
Last Updated: October 2026