Module code: ENG2111

Module Overview

This course provides an introduction to separation processes in general, but with particular emphasis on equilibrium staged separations of binary mixtures.  Processes covered include binary distillation, liquid-liquid extraction and gas absorption and desorption in tray columns. This gives students an appreciation of what lies beneath chemical engineering flow-sheeting and design software packages. This appreciation is enhanced by hands on experience with HYSYS, an industry standard chemical engineering design simulation package.

Module provider

Chemical and Process Engineering

Module Leader


Number of Credits: 15

ECTS Credits: 7.5

Framework: FHEQ Level 5

JACs code: H810

Module cap (Maximum number of students): N/A

Module Availability

Semester 1

Prerequisites / Co-requisites

Completion of the progression requirements to FHEQ Level 5 of the degree courses in Chemical Engineering, Chemical and Bio-Systems Engineering and Chemical and Petroleum Engineering, or equivalent. 

Module content

 Indicative content includes:

Introduction to equilibria and staged separation processes

Minimum work of separation
Vapour liquid equilibria
Multicomponent flashes

Introduction to gas-liquid absorption and stripping in equilibrium staged processes

The definition and use of operating lines
Tray hydraulics
Tray to tray calculations and the Kremser equation

Introduction to distillation

The equimolar overflow concept (plus Trouton’s rule)
The top operating line
The bottom operating line and McCabe-Thiele
The q line
The feed line
Minimum stages and tray efficiency
Advanced columns – pump arounds etc

Batch distillation

Simple batch distillation
Derivation and use of the Rayleigh equation

Advanced binary calculaltions

Ponchon Savarit material and energy balances
Non-adiabatic columns

Introduction to liquid-liquid extraction

Simple multi-stage contactors
Counter-current contact
Total and partial immiscibility, triangular diagrams and stage to stage graphical constructions

HYSYS simulation

Introduction to the package, unit operations, graphical topology, component database, thermodynamic options, convergence, report generation
Checking thermodynamic setting against experimental data
Interpretation of Process description, setting up and running a simulation, convergence to required product rate and specification
Process costing and profitabality


Assessment pattern

Assessment type Unit of assessment Weighting
Examination EXAMINATION (2 HOURS) 65

Alternative Assessment


Assessment Strategy

The assessment strategy is designed to engage the students at an early stage in the semester and provide students with the opportunity to demonstrate all module learning outcomes, through a balanced mix of theoretical questions, design exercises and hands-on HYSYS simulations.

Thus, the summative assessment for this module consists of

Examination – 65%, 2 hours (LO1 – LO3)

Formative assessment – on the material covered in the first eight lectures, namely equilibria, absorption and stripping. (LO1 – LO3), 1 week for completion. Only upon satisfactory completion of this activity will the HYSYS component be marked
HYSYS Individual Submission - 11% after first HYSYS session (Simulation, Report and Simple Calculations) (LO4, LO5)
HYSYS Report – 24%. Submission of a group report, outlining the modelling of the process and including an assessment of the profitability of the process, a critical evaluation of the design and a completed simulation of any process improvements applied (LO3, LO4, LO5)

Formative assessment

Online quizzes associated with progress through HYSYS tutorials

Module aims

  • Provide students with an introduction to equilibria, including binary vapour-liquid systems and ternary liquid-liquid systems.
  • Introduce equilibrium staged separation processes, focussing on gas absorption, binary distillation and liquid-liquid extraction processes.
  • Provide the knowledge and skills to undertake the specification and design of absorption columns, binary distillation columns and liquid liquid extractors (i.e. continuous diffusional contact devices)
  • Familiarise students with a commercially available process modelling package (HYSYS) through hands-on examples

Learning outcomes

Attributes Developed
001 Recognise models used to describe phase equilibirum in ideal mixtures and useful simplifications for non-ideal cases. KC
002 Predict equilibria for binary vapour-liquid and ternary liquid-liquid systems and interpret appropriate graphical representations of these equilibria. KC
003 Design stage processes for gas-liquid absorption (bulk and dilute), binary distillation and liquid-liquid extracion using equilibria, operating and tie lines. KCP
004 Interpret a process description anduse HYSYS to simulate a process. KCP
005 Critically evaluate the output of the simulation and apply a simple costing model to evaluate the profitability of the process and suggest improvements CPT

Attributes Developed

C - Cognitive/analytical

K - Subject knowledge

T - Transferable skills

P - Professional/Practical skills

Overall student workload

Independent Study Hours: 112

Lecture Hours: 22

Tutorial Hours: 14

Laboratory Hours: 2

Methods of Teaching / Learning

The learning and teaching strategy is designed to:

Illustrate fundamental concepts and design procedures during lectures, by presenting them in the context of several worked examples.
Highlight the similarities and differences between the different separation processes, and their design.
Provide the students with opportunities to practice these concepts in carefully selected and thoroughly supervised tutorial sessions.
Allow students to develop hands-on experience of building and analysing complex process models

The learning and teaching methods include:

Separation Processes 1

Lectures                                 2 hours per week for 11 weeks
Tutorial/Problem Classes       1 hours per week for 12 weeks (12 hours total) 
Independent learning             71 hours


Supervised Lab Session        2 hours
Independent study (including online tutorial videos)                41 hours    
Drop in sessions                    2 hours


Indicated Lecture Hours (which may also include seminars, tutorials, workshops and other contact time) are approximate and may include in-class tests where one or more of these are an assessment on the module. In-class tests are scheduled/organised separately to taught content and will be published on to student personal timetables, where they apply to taken modules, as soon as they are finalised by central administration. This will usually be after the initial publication of the teaching timetable for the relevant semester.

Reading list


Programmes this module appears in

Programme Semester Classification Qualifying conditions
Chemical and Petroleum Engineering BEng (Hons) 1 Compulsory A weighted aggregate mark of 40% is required to pass the module
Chemical Engineering BEng (Hons) 1 Compulsory A weighted aggregate mark of 40% is required to pass the module
Chemical Engineering MEng 1 Compulsory A weighted aggregate mark of 40% is required to pass the module
Chemical and Petroleum Engineering MEng 1 Compulsory A weighted aggregate mark of 40% is required to pass the module

Please note that the information detailed within this record is accurate at the time of publishing and may be subject to change. This record contains information for the most up to date version of the programme / module for the 2020/1 academic year.