United Arab Emirates University Chemical and Petroleum Engineering

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United Arab Emirates UniversityChemical and
Petroleum Engineering
Desalination of seawater using exhaust CO2

• Presented By
• Ahmad Hussain AlHossany
• Adeeb Omar Bamatraf
• Mohamad Jamal El-Cadi
• Saleh Mohammed Mohammed
• Advisor Co-advisors
• Dr. Ali Al-Marzouqi Dr. Omar Chaalal

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Water Desalination

• The Na of seawater is 14,000 ppm.
• Brackish Water with Na of 1000 4000 ppm is
  suitable for irrigation (depending on crops).
• Saline type agriculture is under research to use
  saline water up to Na of 10,000 ppm.
• Water demands include
• Domestic use
• Agriculture use
• Industrial use

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Main Desalination Technologies
Multi-Stage Flash (MSF)
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Gas Flaring in the UAE
Total Gas Flaring in the UAE 83 MMSCFD
MMSCFD
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OBJECTIVE
Propose a practical process, at low cost, for
producing large quantities of brackish water,
using CO2 from combustion exhaust, which
otherwise would be contaminating the environment.

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Advantages of the proposed process

• Low energy consumption low cost.
• Raw materials available at low cost.
• Produce brackish water for irrigation purposes.
• Produce valuable by-products.
• Solves two environmental problems
• Reduce CO2 emissions to the atmosphere.
• Treatment of reject brine or formation water.

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Theory

• - The absorbed CO2 reacts with ammonia in the
  ammoniated brine to form carbamic acid.
• CO2 NH3 NH2COOH (carbamic acid )
  (1)
• - Carbamic acid reacts with ammonia to form
  ammonium carbamate.
• NH3 NH2COOH NH4 NH2COO-
  (2)
• - The overall reaction is given as (Primary Rxn.)
  
• CO2 2NH3 NH2COO-
  NH4 (3)
• - The carbonate slowly converts into bicarbonate
  (Secondary Rxn.)
• NH2COO- H2O NH3 HOCOO-
  (4)

• Main Reaction
• NaCl (aq) NH3 (aq) H2O (l) CO2(g)
  NaHCO3 (s) NH4Cl(aq)

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EXPERIMENTAL WORK

• Aim
• To investigate the optimum conditions that give
• the best quality of irrigation water.
• - Temperature
• - Pressure
• - Concentration of NaCl
• - Concentration of Ammonia
• - CO2 flow rate
• - Mixing
• - Time

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Experimental Setup
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PRECIPITATE
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Experimental Work
Trial NH4OH (ml) Seawater (ml) Total (ml)
1 7 193 200
2 15 185 200
3 30 170 200
4 50 150 200
5 100 100 200
6 150 50 200
Experiments were conducted at 25 oC
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Process Flow Diagram
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Evaporation required for different feed types
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HEALTH, SAFETY ENVIRONMENTAL REGULATIONS
Safety of the employees - Complete training
on each piece of equipment - Wear personal
protective equipment The operating conditions
(i.e. P, T, and concentration of chemicals) will
always be within OSHA regulations and limits
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Conclusion

• Effects of different parameters were
  investigated.
• Optimum Conditions
• T 20 oC
• P 2 atm
• CO2 Flow Rate to reactor 2 L/min
• NH3/NaCl Ratio 1
• Time of reaction 2 hrs

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Conclusion

• Proposed process has a low energy consumption
  since exhaust gases are available at high
  temperature.
• Most of the raw materials are readily available
  at low cost.
• Proposed process solves two environmental
  problems
• Reduce CO2 emissions to the atmosphere.
• Treatment of reject brine or formation water.

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• Thank You for Your Attention

Questions ????