際際滷

際際滷Share a Scribd company logo

MANUFACTURE OF CHLORINE - CAUSTIC SODA USING ELECTROLYSIS PROCESS (MEMBRANE CELL) * CORRECTION NEEDED

Download as PPT, PDF
Ankush Gupta
Ankush Gupta

This document summarizes the process of manufacturing chlorine and caustic soda using electrolysis. It includes: - A process flow diagram of the membrane cell process used to separate NaCl into NaOH, H2, and Cl2 via electrolysis. - Material and energy balances calculations for each unit operation including the membrane cell, evaporator, and dryer. These calculate chemical reactions, flows, heating needs and efficiencies. - The process achieves 70.28% conversion of NaCl and 27.37% yield of NaOH from the reacted NaCl. Waste streams and energy requirements are also quantified.

1 of 19
Downloaded 658 times
PROJECT TOPIC MANUFACTURE OF CHLORINE CAUSTIC SODA USING ELECTROLYSIS PROCESS BHARATI VIDYAPEETH COLLEGE OF ENGINEERING CHEMICAL DEPARTMENT Prof. R.K.Kulkarni Presented by Ankush Gupta
PROCESS FLOW DIAGRAM Membrane Cell Process
MANUFACTURE OF CHLORINE - CAUSTIC SODA USING ELECTROLYSIS PROCESS (MEMBRANE CELL) * CORRECTION NEEDED
MATERIAL BALANCE
Basis : 1150 kg/hr NaOH , 1000 kg/hr Chlorine 2NaCl + 2H2O 2NaOH + H2 + Cl2 (58.5) (18) (40) (2) (70) (28.75) (28.75) (28.75) (14.375) (14.375) Kmoles/hr (1681.8) (517.5) (1150) (28.75) (1006) kg/hr Sample calculation Moles = weight / molecular weight For NaCl Moles = 1150/40 28.75 Kmol/hr NaCl required (Kg) = 28.75 * 58.5 1681.8 kg (1700 Kg/hr).
Assumption : 1700 kg/hr of NaCl 20 kg/hr Na2Co3 15/100 x Feed =1700 Feed = 11333.33 Kg/hr. OVERALL MATERIAL BALANCE Feed (F) + Na2Co3 = |Sludge|4 + |NaCl|3 11333.33 + 20 = |Sludge|4+ |NaCl|3eqn(1) MATERIAL BALANCE OF NaCl 1700 = 28%|NaCl|3 + 10%|Sludge|4 170000 = 28|NaCl|3 + 10|Sludge|4.eqn(2) On Solving Eqn(1) & eqn(2) we get |NaCl|3 = 3137.03 Kg/hr. |Sludge|4 = 8216.3 Kg/hr.
For 55% efficiency of Caustic Soda &Cl2: 2NaCl + 2H2O = 2NaOH + H2 + Cl2 Mass flow(kg/hr) 878.36 270.25 330.28 8.256 289.01 Molecular Weight 58.5 18 40 2 70 Moles flow(Kmol/hr) 15.014 15.014 15.104 7.552 7.552 Moles flow(Kmol/hr) 8.257 8.257 8.257 4.153 4.153 (55%) Sample Calculation: For NaOH : Amount of NaCl entering a membrane cell = 28%|NaCl|3=28% (3137.03)=878.368kg/hr Converting into molar flow rate = 878.368/58.5=15.014 Kmol/hr By Stoichiometry , No of moles of NaCl = No of moles of NaOH = 15.014 Kmol/hr. But since we have for 55% efficiency for Membrane cell No of moles of NaOH = 55%(15.014)= 8.257 Kmol/hr. Therefore the amount of NaOH obtained= 8.257*40=330.28 Kg/hr
OVERALL MATERIAL BALANCE OVER EVAPORATOR Aq. NaOH(35%NaOH) = Aq.NaOH(50% NaOH) + Water vapour 330.28 = 231.196 + 99.081 Calculation for amount of aq.NAOH obtained as a main product: Pure NaOH out of aq. NaOH = 35% of (330.28) = 115.598 kg/hr Water content in incoming aq. NaOH = 330.28 115.98 = 214.68 kg/hr Amount of NaOH obtained after 50% concentration is 50% of (aq. NaOH) = 115.598 kg/hr Therefore aq. NaOH (50%) obtained as product = 231.196 kg/hr Water content in obtained aq. NaOH (50%) = 231.196-115.598=115.598 kg/hr Therefore Water Vapour = 214.68-115.98=99.082 kg/hr
OVERALL MATERIAL BALANCE OVER DRYER: Wet Cl2 + H2SO4(98% conc) = Dry Cl2 + H2SO4 (70% conc) 289.019 + 98% of (25kg) = Dry Cl2 + H2SO4 (70%) .eqn1 MATERIAL BALANCE OF H2SO4 OVER DRYER: Inlet H2SO4 (98%conc) = Outlet H2SO4 (70%conc) 98%(25) = 70% H2SO4 98x25 = 70% H2SO4 H2SO4 (70%) = 35 kg/hr Substituting in ..eq1 Dry Cl2 = 278.519 kg/hr.
ENERGY BALANCE
STEAM REQUIREMENT FOR HEATING BRINE m = mass flow rate of Aq NaCl in kg/hr CP= specific heat capacity of Aq NaCl At 60O C T = Temperature Difference 了 = latent Heat of evaporization in kJ/kg m1 = Flow rate of steam kJ/hr mcPT = m1 了 3137.03 x 3.274 (333-298) = m x 2358.40 m1 = 151.186 kJ/hr
ENERGY BALANCE OVER MEMBRANE CELL Assumption Datum temperature = 25o C INLET STREAM OUTLET STREAM MATERI AL NAME SPECIFIC HEAT AT 60o C FLOW RATES kg/hr H2O 4.185 kJ/kgK 270.252 Aq.NacL solution 3.247 kJ/kgK 876.368 MATERIAL NAME SPECIFIC HEAT AT 80o C FLOW RATES kg/hr Hydrogen (g) 14.43 kJ/kgK 8.256 Chlorine (l) 0.48 kJ/kgK 289.019 NaoH (35% by wt) 3.594 kJ/kgK 330.28 Depleted brine 3.247 kJ/kgK 521.065
INPUT STREAM Material mcPT Aq .NaCl 876.368 x 3.247x (333-298) = 99594.84 kJ/hr H2O 270.252 x 4.185 x (333-298) = 39585.16 kJ/hr TOTAL HEAT INPUT = 99594.84 + 39585.16 = 139180 kJ/hr OUTPUT STREAM Material mcPT Hydrogen (g) 8.256 x 14.43 x (353-298) = 6552.37 kJ/hr Chlorine (l) 0.48 x 289.019 x(353-298) = 4855.51 kJ/hr Aq.NaoH 3.594 x 330. 28 x (353-298) = 41545.92 kJ/hr Depleted Brine 3.247 x 521. 065 x (353-298)= 59216.43 kJ/hr TOTAL HEAT OUTPUT = 6552.37 + 4855.51 + 41545.92 + 59216.43 = 112170.23 kJ/hr 2Na (s) + 2H2O 2NaOH + H2O H = -368.4 kJ/gmNa Depleted brine = 526.064 kg/hr (50% by wt of NaCl) 0.5 x 526.064 x -368.4 = - 96900.98 J/hr
MATERIAL NAME SPECIFIC HEAT AT 80o C FLOW RATES kg/hr Aq.NaoH 35% by wt 3.594 kJ/kgK 330.28 MATERIAL NAME SPECIFIC HEAT AT 110o C FLOW RATES kg/hr 50 % Caustic soda 3.564 kJ/kgK 231.196 INLET STREAM OUTLET STREAM MATERIAL NAME Latent Heat AT 110o C FLOW RATES kg/hr Steam 2231.86 kJ/kg 94.127 ENERGY BALANCE OVER EVAPORATOR
INPUT STREAM Material mcPT Aq .NAOH 330.28 x 3.594 x (353-298) = 65286.44 kJ/hr TOTAL HEAT INPUT = 65286.44 kJ/hr OUTPUT STREAM Material mcPT Aq.NaoH (50% by wt) 231.196 x 3.564 x (383-298) = 45319.03 kJ/hr Material m了 Water vapour (g) 94.127 x 2231.86 = 210078.28 kJ/hr TOTAL HEAT OUTPUT = 45319.03 + 210078.28 = 255397.31 kJ/hr
MATERIAL NAME SPECIFIC HEAT FLOW RATES kg/hr Wet chlorine 0.48 kJ/kgK 289.019 H2SO4 (98% by wt) 1.465 kJ/kgK 10 MATERIAL NAME SPECIFIC HEAT FLOW RATES kg/hr Dry chlorine 0.48 kJ/kgK 285.019 H2SO4 (70% by wt) 2.177 kJ/kgK 14 INLET STREAM OUTLET STREAM ENERGY BALANCE OVER DRYER
INPUT STREAM Material mcPT Wet Chlorine 289.019 x 0.48 x (353-298) = 7630.10kJ/hr TOTAL HEAT INPUT = 7630.10 kJ/hr OUTPUT STREAM Material mcPT Dry Chlorine (l) 285.019 x 0.48 x (343-298) = 6156.41 kJ/hr H2SO4 70% 14 x 2.177 x (303-298) = 152.39 kJ/hr TOTAL HEAT OUTPUT = 6156.41 + 152.39 = 6308.8 kJ/hr
% conversion NaCl = (Reacted moles / Total no moles) x 100 = {(878.36 261.032)/878.36} x 100 = 70.28 % %Yield = (NaoH moles Formed /Reacted moles of NaCl) x 100 = {(115.598/ 40) / (617.328/58.5) } x 100 = 27.37 %
REFERENCES 1 ) Subrata Basu , Swapan Kumar Mukhopadhyay , Amitava Gangopadhyay and Sujata G. Dastidar International Research Journal of Environment Sciences Characteristic Change of Effluent from a Chlor-alkali Industry of India due to Process Modification 2013. 2) S.Koter.A.Warszawski Polish Journal of Environmental Studies Electro- membrane Processes in Environment Protection (2000) 3) Yohannes Kiros and Martin Bursell International Journal Electrochemistry Science Low Energy Consumption in Chlor-alkali Cells Using Oxygen Reduction Electrodes (2008) 4) Rezaee, J. Derayat, S.B. Mortazavi,Y. Yamini and M.T. Jafarzadeh American Journal of Environmental Sciences Removal of Mercury from Chlor-alkali Industry Wastewater using Acetobacter xylinum Cellulose(2005) 5) Drydens outlines of chemical technology (2012)

More Related Content

MANUFACTURE OF CHLORINE - CAUSTIC SODA USING ELECTROLYSIS PROCESS (MEMBRANE CELL) * CORRECTION NEEDED

  • 1. PROJECT TOPIC MANUFACTURE OF CHLORINE CAUSTIC SODA USING ELECTROLYSIS PROCESS BHARATI VIDYAPEETH COLLEGE OF ENGINEERING CHEMICAL DEPARTMENT Prof. R.K.Kulkarni Presented by Ankush Gupta
  • 5. Basis : 1150 kg/hr NaOH , 1000 kg/hr Chlorine 2NaCl + 2H2O 2NaOH + H2 + Cl2 (58.5) (18) (40) (2) (70) (28.75) (28.75) (28.75) (14.375) (14.375) Kmoles/hr (1681.8) (517.5) (1150) (28.75) (1006) kg/hr Sample calculation Moles = weight / molecular weight For NaCl Moles = 1150/40 28.75 Kmol/hr NaCl required (Kg) = 28.75 * 58.5 1681.8 kg (1700 Kg/hr).
  • 6. Assumption : 1700 kg/hr of NaCl 20 kg/hr Na2Co3 15/100 x Feed =1700 Feed = 11333.33 Kg/hr. OVERALL MATERIAL BALANCE Feed (F) + Na2Co3 = |Sludge|4 + |NaCl|3 11333.33 + 20 = |Sludge|4+ |NaCl|3eqn(1) MATERIAL BALANCE OF NaCl 1700 = 28%|NaCl|3 + 10%|Sludge|4 170000 = 28|NaCl|3 + 10|Sludge|4.eqn(2) On Solving Eqn(1) & eqn(2) we get |NaCl|3 = 3137.03 Kg/hr. |Sludge|4 = 8216.3 Kg/hr.
  • 7. For 55% efficiency of Caustic Soda &Cl2: 2NaCl + 2H2O = 2NaOH + H2 + Cl2 Mass flow(kg/hr) 878.36 270.25 330.28 8.256 289.01 Molecular Weight 58.5 18 40 2 70 Moles flow(Kmol/hr) 15.014 15.014 15.104 7.552 7.552 Moles flow(Kmol/hr) 8.257 8.257 8.257 4.153 4.153 (55%) Sample Calculation: For NaOH : Amount of NaCl entering a membrane cell = 28%|NaCl|3=28% (3137.03)=878.368kg/hr Converting into molar flow rate = 878.368/58.5=15.014 Kmol/hr By Stoichiometry , No of moles of NaCl = No of moles of NaOH = 15.014 Kmol/hr. But since we have for 55% efficiency for Membrane cell No of moles of NaOH = 55%(15.014)= 8.257 Kmol/hr. Therefore the amount of NaOH obtained= 8.257*40=330.28 Kg/hr
  • 8. OVERALL MATERIAL BALANCE OVER EVAPORATOR Aq. NaOH(35%NaOH) = Aq.NaOH(50% NaOH) + Water vapour 330.28 = 231.196 + 99.081 Calculation for amount of aq.NAOH obtained as a main product: Pure NaOH out of aq. NaOH = 35% of (330.28) = 115.598 kg/hr Water content in incoming aq. NaOH = 330.28 115.98 = 214.68 kg/hr Amount of NaOH obtained after 50% concentration is 50% of (aq. NaOH) = 115.598 kg/hr Therefore aq. NaOH (50%) obtained as product = 231.196 kg/hr Water content in obtained aq. NaOH (50%) = 231.196-115.598=115.598 kg/hr Therefore Water Vapour = 214.68-115.98=99.082 kg/hr
  • 9. OVERALL MATERIAL BALANCE OVER DRYER: Wet Cl2 + H2SO4(98% conc) = Dry Cl2 + H2SO4 (70% conc) 289.019 + 98% of (25kg) = Dry Cl2 + H2SO4 (70%) .eqn1 MATERIAL BALANCE OF H2SO4 OVER DRYER: Inlet H2SO4 (98%conc) = Outlet H2SO4 (70%conc) 98%(25) = 70% H2SO4 98x25 = 70% H2SO4 H2SO4 (70%) = 35 kg/hr Substituting in ..eq1 Dry Cl2 = 278.519 kg/hr.
  • 11. STEAM REQUIREMENT FOR HEATING BRINE m = mass flow rate of Aq NaCl in kg/hr CP= specific heat capacity of Aq NaCl At 60O C T = Temperature Difference 了 = latent Heat of evaporization in kJ/kg m1 = Flow rate of steam kJ/hr mcPT = m1 了 3137.03 x 3.274 (333-298) = m x 2358.40 m1 = 151.186 kJ/hr
  • 12. ENERGY BALANCE OVER MEMBRANE CELL Assumption Datum temperature = 25o C INLET STREAM OUTLET STREAM MATERI AL NAME SPECIFIC HEAT AT 60o C FLOW RATES kg/hr H2O 4.185 kJ/kgK 270.252 Aq.NacL solution 3.247 kJ/kgK 876.368 MATERIAL NAME SPECIFIC HEAT AT 80o C FLOW RATES kg/hr Hydrogen (g) 14.43 kJ/kgK 8.256 Chlorine (l) 0.48 kJ/kgK 289.019 NaoH (35% by wt) 3.594 kJ/kgK 330.28 Depleted brine 3.247 kJ/kgK 521.065
  • 13. INPUT STREAM Material mcPT Aq .NaCl 876.368 x 3.247x (333-298) = 99594.84 kJ/hr H2O 270.252 x 4.185 x (333-298) = 39585.16 kJ/hr TOTAL HEAT INPUT = 99594.84 + 39585.16 = 139180 kJ/hr OUTPUT STREAM Material mcPT Hydrogen (g) 8.256 x 14.43 x (353-298) = 6552.37 kJ/hr Chlorine (l) 0.48 x 289.019 x(353-298) = 4855.51 kJ/hr Aq.NaoH 3.594 x 330. 28 x (353-298) = 41545.92 kJ/hr Depleted Brine 3.247 x 521. 065 x (353-298)= 59216.43 kJ/hr TOTAL HEAT OUTPUT = 6552.37 + 4855.51 + 41545.92 + 59216.43 = 112170.23 kJ/hr 2Na (s) + 2H2O 2NaOH + H2O H = -368.4 kJ/gmNa Depleted brine = 526.064 kg/hr (50% by wt of NaCl) 0.5 x 526.064 x -368.4 = - 96900.98 J/hr
  • 14. MATERIAL NAME SPECIFIC HEAT AT 80o C FLOW RATES kg/hr Aq.NaoH 35% by wt 3.594 kJ/kgK 330.28 MATERIAL NAME SPECIFIC HEAT AT 110o C FLOW RATES kg/hr 50 % Caustic soda 3.564 kJ/kgK 231.196 INLET STREAM OUTLET STREAM MATERIAL NAME Latent Heat AT 110o C FLOW RATES kg/hr Steam 2231.86 kJ/kg 94.127 ENERGY BALANCE OVER EVAPORATOR
  • 15. INPUT STREAM Material mcPT Aq .NAOH 330.28 x 3.594 x (353-298) = 65286.44 kJ/hr TOTAL HEAT INPUT = 65286.44 kJ/hr OUTPUT STREAM Material mcPT Aq.NaoH (50% by wt) 231.196 x 3.564 x (383-298) = 45319.03 kJ/hr Material m了 Water vapour (g) 94.127 x 2231.86 = 210078.28 kJ/hr TOTAL HEAT OUTPUT = 45319.03 + 210078.28 = 255397.31 kJ/hr
  • 16. MATERIAL NAME SPECIFIC HEAT FLOW RATES kg/hr Wet chlorine 0.48 kJ/kgK 289.019 H2SO4 (98% by wt) 1.465 kJ/kgK 10 MATERIAL NAME SPECIFIC HEAT FLOW RATES kg/hr Dry chlorine 0.48 kJ/kgK 285.019 H2SO4 (70% by wt) 2.177 kJ/kgK 14 INLET STREAM OUTLET STREAM ENERGY BALANCE OVER DRYER
  • 17. INPUT STREAM Material mcPT Wet Chlorine 289.019 x 0.48 x (353-298) = 7630.10kJ/hr TOTAL HEAT INPUT = 7630.10 kJ/hr OUTPUT STREAM Material mcPT Dry Chlorine (l) 285.019 x 0.48 x (343-298) = 6156.41 kJ/hr H2SO4 70% 14 x 2.177 x (303-298) = 152.39 kJ/hr TOTAL HEAT OUTPUT = 6156.41 + 152.39 = 6308.8 kJ/hr
  • 18. % conversion NaCl = (Reacted moles / Total no moles) x 100 = {(878.36 261.032)/878.36} x 100 = 70.28 % %Yield = (NaoH moles Formed /Reacted moles of NaCl) x 100 = {(115.598/ 40) / (617.328/58.5) } x 100 = 27.37 %
  • 19. REFERENCES 1 ) Subrata Basu , Swapan Kumar Mukhopadhyay , Amitava Gangopadhyay and Sujata G. Dastidar International Research Journal of Environment Sciences Characteristic Change of Effluent from a Chlor-alkali Industry of India due to Process Modification 2013. 2) S.Koter.A.Warszawski Polish Journal of Environmental Studies Electro- membrane Processes in Environment Protection (2000) 3) Yohannes Kiros and Martin Bursell International Journal Electrochemistry Science Low Energy Consumption in Chlor-alkali Cells Using Oxygen Reduction Electrodes (2008) 4) Rezaee, J. Derayat, S.B. Mortazavi,Y. Yamini and M.T. Jafarzadeh American Journal of Environmental Sciences Removal of Mercury from Chlor-alkali Industry Wastewater using Acetobacter xylinum Cellulose(2005) 5) Drydens outlines of chemical technology (2012)
AboutCopyright
息 2025 際際滷