Transcript Electrical Resistance Tomography ERT

Electrochemical Reactors
Quak Foo Lee
Department of Chemical and Biological Engineering
The University of British Columbia
Introduction
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In electrochemical reactions, electrons are supplied to
a reactant in the electrolyte or removed from it with
the aid of an electric current.
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A minimum voltage called the decomposition voltage
must be applied to the electrodes for this purpose.
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In addition to the electrochemical reactions occurring
on the electrode surface, transport processes and
chemical reactions in the electrolyte both are
important.
Reactors for Electrochemical
Processes
A) Metal winning by fused-salt electrolysis; B) Electrolytic metal refining; C) Electrolysis of inorganic material; D) Electrolysis of organic material; E) Mercury
amalgam process; F) Diaphragm-cell process; G) Membrane process
a) Water; b) Chlorine; c) Sodium chloride; d) Hydrogen; e) Sodium; f) Sodium hydroxide; g) Anode; h) Cathode; i) Membrane; j) Product; k) Amalgam; l)
Recycle brine + chlorine; m) Mercury; n) Graphite; o) Diaphragm; p) Electrolytic salt solution of metal to be refined; q) Anode slime; r) Electrolyte removal;
s) Organic feed solution; t) Oxygen
Advantages
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High product purity (no secondary reactions)
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Low reaction temperature (except for fusedsalt electrolysis)
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Easy control of reaction rate through variation
of electrode voltage
Disadvantages
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High energy losses in the system
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Large space requirement
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High investment costs
When to Use Electrochemical
Reactor?
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Electrochemical processes are used only
when no available thermal or catalytic
process can accomplish the same purpose,
which is especially true in the production of
chlorine, aluminum, and copper.
Applications
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Chlorine production by chlor – alkali electrolysis
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Metal winning by fused-salt electrolysis
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Mercury amalgam process
Diaphragm-cell process
Membrane process
Aluminum
Magnesium
Sodium
Metal refining
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Copper
Nickel
Applications
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Electrolysis of inorganic materials
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Electrolysis of water
Fluorine production by electrolysis of hydrogen fluoride
Production of sodium chlorate by electrolysis of sodium chloride
Electrochemical oxidation of sodium chlorate to perchlorate
Recovery of persulfuric acid
Production of ozone
Electrolysis of organic materials
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Production of adiponitrile from acrylonitride
Production of dimenthyl sebacate
Reduction of nitrobenzene to aniline