1. Electrochemical Reactors
Quak Foo Lee
Department of Chemical and Biological Engineering
The University of British Columbia

2. Introduction
In electrochemical reactions, electrons are supplied to a reactant in the electrolyte or removed from it with the aid of an electric current.
A minimum voltage called the decomposition voltage must be applied to the electrodes for this purpose.
In addition to the electrochemical reactions occurring on the electrode surface, transport processes and chemical reactions in the electrolyte both are important.

3. 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

4. Advantages High product purity (no secondary reactions)
Low reaction temperature (except for fused-salt electrolysis)
Easy control of reaction rate through variation of electrode voltage

5. Disadvantages High energy losses in the system Large space requirement
High investment costs

6. When to Use Electrochemical Reactor?
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.

7. Applications Chlorine production by chlor – alkali electrolysis
Mercury amalgam process
Diaphragm-cell process
Membrane process
Metal winning by fused-salt electrolysis
Aluminum
Magnesium
Sodium
Metal refining
Copper
Nickel

8. Applications Electrolysis of inorganic materials
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
Production of adiponitrile from acrylonitride
Production of dimenthyl sebacate
Reduction of nitrobenzene to aniline