Presentation on theme: "Electrochemical Reactors"— Presentation transcript:
1Electrochemical Reactors Quak Foo LeeDepartment of Chemical and Biological EngineeringThe University of British Columbia
2IntroductionIn 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.
3Reactors 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
4Advantages High product purity (no secondary reactions) Low reaction temperature (except for fused-salt electrolysis)Easy control of reaction rate through variation of electrode voltage
5Disadvantages High energy losses in the system Large space requirement High investment costs
6When 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.
7Applications Chlorine production by chlor – alkali electrolysis Mercury amalgam processDiaphragm-cell processMembrane processMetal winning by fused-salt electrolysisAluminumMagnesiumSodiumMetal refiningCopperNickel
8Applications Electrolysis of inorganic materials Electrolysis of waterFluorine production by electrolysis of hydrogen fluorideProduction of sodium chlorate by electrolysis of sodium chlorideElectrochemical oxidation of sodium chlorate to perchlorateRecovery of persulfuric acidProduction of ozoneElectrolysis of organic materialsProduction of adiponitrile from acrylonitrideProduction of dimenthyl sebacateReduction of nitrobenzene to aniline