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A Study on Electrochemistry of PKL (Pathor Kuchi Leaf) Electrochemical Cell
Mohammad Al MamunAssistant Professor
Department of Chemistry Jagannath University
Emission of green house gas CO2
• Rising temperature• Shrinking habitat• Food harder to get • Expanding diseases• Competition• Animals at risk
Green House Effect
To Combat
Global Warming
Separation
Capture
Sequesteron
Conversion
Solar Cells
Fuel Cells
Hydrogen Economy
Energy Storage Batteries
Supercapacitors
Carbon ManagementUse of High Strength Materials
Nanocatalysts to improve Fuel Efficiency
Reducing Friction in Engines
Improve Insulation for Buildings
Advanced Lighting Technology
Chemical Electrochemical Photo electrochemical
Reduced Energy
Consumptionand
ImprovingEfficiency
Renewable Energy
andStorage
Technology
Electrochemical Cell
Electrochemical Cell
■ Electrochemical reaction – transfer of electron - Electricity
Zn (s) + Cu2+(aq) = Zn2+(aq) + Cu (s) ■ Anode – Oxidation : Donation of electron-Half cell reaction
Zn(s) – 2e- = Zn 2+ (aq)
■ Cathode - Reduction : Gaining of electron – Half cell reaction Cu 2+ (aq) + 2e- = Cu (s)
■ Electrolytic Medium : Elimination of migration current.
Zn is anode but Cu is cathode - Why?Standard Reduction Potentials in Aqueous Solution at 25° C
Strongly held outerm
ost electron
Zn2+ (aq) + 2e- Zn (s) -0.76
Different types of electrode
Carbon paste electrode
Glassy carbon electrodeModified glassy carbon electrode
Potentiometric Cell
Subs
trat
eTr
ansd
uctio
n la
yer
Bio
reco
gniti
on la
yer
Electrochemical Cell
■ Voltaic Cell Chemical Energy Electrical
Energy
■ Electrolytic cell Electrical Energy
Chemical Energy
Electrolytic Cell
Electrochemical Cell - Current
• Diffusion Current – concentration gradient
• Migration Current – moment of charged particle along an electric field
• Convection Current - physical movement - stirring
Comparision - Schematic
Electrolytic CellVoltaic Cell
2Cl- - e- Cl2 2Na+ + e- 2Na
Comparision - Schematic
H2-O2 fuel cellConcentration cell
Comparision - Schematic
Dry cell Lead storage battery
Alkaloids & Minerals
Organic Acids: ●Palmitic Acid ●Stearic Acid ●Oxalic Acid ●Citric Acid ●Isocitric Acid ●Malic Acid●Succinic Acid●Ascorbic Acid●Amino Acids etc.
▪ Triterpenes, ▪ Glycosides, ▪ Flavonoids, ▪Cardienolides,▪ Steroids, ▪Bufadienolides and ▪ Lipids
Hypothesis -Photosynthesis
PKL Juice Preparation
PKL PKL + Water ( Blending)
Filtration
PKL Solution
Filtration
Without
PKL SuspensionSolid Wastage
Comparision - Schematic
Zn2+
SO42-
Cu2+
SO42-
1 MZnSO4 solution
1 MCuSO4 solution
Zn Anode Cu Cathode
Voltaic Cell (Unit cell)
Digital voltmeter
Zn Anode
40% PKL soln
5% CuSO4
e- e-
PKL Cell
(Unit cell)
Cu Cathode
For electrolytic studies the analyzed PKL Malt/Juice/Sap put in between Zn and Cu flat parallel electrodes with various surface areas separated say a 0.5 ±0.1 cm gaps and discharged using an external load. Using this process we get a unit PKL cell, module, Panel & arrays.
PKL Module
PKL Module Design
Practical Applications•15 kilowatt hr electricity -1 kg of leaves are required.
At a Glancé
Current and Potential Profile
pH Profile
Identification of H2 gas
AAS Analysis
Atomic Absorption Spectrophotometer
AAS Analysis
Ecell = Eoxidation (0.76) + Ereduction (0)° means standard conditions:
1atm, 1M, 25C
How can we determine the Cell EMF ?
Hydrogen ElectrodeVoltaic Cell
Ecathode (0.34 V)Eanode (0.76 V)
How can we determine the Cell EMF ?Ecell
Ecell = E
ox + Ered = 0.76+0.34 = 1.10 V
Theory – Nernst Equation Ecell = E °cell - RT log Q
nF Ecell = E °cell - 0.0592 log Q @ 25°C(298K)
n Ered = E °red - RT log Q
nF Ered = E °red - 0.0592 log Q @ 25°C(298K)
nQ = [Oxidised state]α/[Reduced state]β
α and β are stoichiometric coefficient
Theory – Spontaneity G = - nFEG = - nFE ; ; G = - RTlnK G = - RTlnK
G = Gibbs free energy [Reaction is spontaneous G = Gibbs free energy [Reaction is spontaneous if ΔGif ΔG isis
negative]negative]n = number of moles of electrons. n = number of moles of electrons. F = Faraday constant 9.6485309 x 10F = Faraday constant 9.6485309 x 1044 J/V (1 J/V (1
mol of mol of electrons carries 96,500C )electrons carries 96,500C )E = cell potentialE = cell potentialR = 8.31 J/mol.KR = 8.31 J/mol.KT = Kelvin temperatureT = Kelvin temperatureK = equilibrium constant K = equilibrium constant
[products][products]coeffcoeff/[reactants]/[reactants]coeffcoeff
Probable Electrochemical Reaction in PKL Cell
Anode : Zn → Zn2+ + 2e-, Cathode : 2H+ + 2e- → H2,
Cell : Zn + 2H+ → Zn2+ + H2,
Role of CuSO4 in PKL Cell■ Supporting electrolyte■ Depolarizer■ Secondary Salt (effect)■ Increase the cell EMF
Comparision – life time
• The organic acids are weak acid. These weak Organic acids dissociates in the solution very slowly and that is why longevity of the PKL Sap/Solution for electricity generation is more than the normal Voltaic cell.
• Once a mixture is prepared for producing electricity, it serves the purpose for 6 months continuously
Comparision – Cost
Cost of PKL cell is ~ 4 times less than the conventional Galvanic cell.
Cost of PKL cell is ~ 2.5 times less than the conventional storage battery
Cost of PKL cell is ~ 5 times less than the conventional Solar cell
Recycling Ability
Charging
Discharging
• The conversion efficiency of the PKL electricity can be expressed as:
η = P output / P input where, η =Conversion efficiency P output =Useful PKL electric power P input = Input PKL electric power
• The conversion efficiency lies between 0 & 1.That is 0< η<1. At present we got the maximum conversion efficiency is around 69%.
Efficiency of the PKL Electricity
Equivalent circuit of PKL cell
Conclusion
PKL cell :■ less expensive ■ highly efficient ■ longer shelf-life ■ environmentally friendly■ introduce a sustainable platform to combat the power crisis of this world in future.
Fig. Electrochemical mechanism of PKL cell electricity generation system : (a) pH , short circuit (SC) and open circuit (OP) voltage profile and (b) concentration profile of Zn2+ and Cu2+ ions in PKL electrochemical cell.
Thanks for your kind attention
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