Assignment 1 - 2012

Due date(s):	14 September 2012
(PDF)	Assignment questions
(PDF)	Assignment solutions

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Assignment objectives

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There are several viewpoints we can use to understand separation processes. One is to consider them based on the mechanism being exploited; another is to consider them based on separations of solids, liquids and gases from various combinations of each other.

.. question::

Fill in the grid of 9 squares (shown in class on 7 September) with as many unit operations as possible.

For each of the nine entries, give an actual unit and state what the streams in and out of the unit are. For example, cryogenic distillation columns are used during gas from gas separation for nitrogen (major) vs oxygen (minor) separations.

.. question::

#. Identify the mechanism by which the components are being separated in the following instances. For example, when concentrating orange juice in an evaporator, we are exploiting the difference in *volatility* between water, and the complex aqueous compounds that make up the juice.

#. Also identify the separating agent and state whether it is an MSA or ESA.

*Unit operations to consider*:

* Waste water treatment: secondary clarifier * Distillation column separating methanol and water * A chromatography column * Drying laundry * Protein purification using a membrane * Liquid-liquid (solvent) extraction

.. question::

Give actual example(s) of where the following mechanism could be used to split components from a given feed stream. State what is in the feed stream and the output separated streams. Also state the name of a unit operation that exploits this mechanism to cause the separation.

* Density * Particle size * Solubility * Mobility * Charge * Phase change * Magnetism

.. question::

Separation processes cannot operate without bounds (energy input into the process is expensive). But in some instances we are constrained also by the nature of the products being separated. Give examples of a separation process where we have to meet additional constraints on the design and operation of the unit in terms of:

* temperature * contamination from other sources (human, airborne, limited choices of solvents to separate the components)

For example, in protein separation, we have to ensure the proteins remain in an aqueous phase, else they will denature, in other words, they are sensitive to the chemical environment.

.. question::

For each of the following general industries, please identify two separation systems (unit operations):

* petrochemical * bioprocessing * food and beverage * pharmaceutical * minerals/mining * metals * air products * wastewater treatment

.. question::

A particle 1mm in diameter, with density of 5000 :math:`\text{kg.m}^{-3}` is settling in an unhindered environment of water. Calculate an estimate of its terminal velocity.

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