Residual Analysis of the Production of Nitric Acid

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Residual Analysis of the Production of Nitric Acid
Erik Tolonen
Nick Poulin
Environmental Engineering Environmental Planning
and Decision Making ENVE4104
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Residual Analysis
Residuals are leftover material and energy from
industrial processes
Residuals can be harmful to the environment
RA Can be used to analyses a process and increase
its efficiency
We are only focusing on the production side for
simplicity
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Background
Unstable in its liquid form, decomposes quickly
into nitrous oxides
Completely miscible with water, mainly produced
and used in its aqueous state
Nitric Acid among the 10 chemicals produced in
the largest amounts
Used for explosives, dyes and most importantly
Fertilizers
High Pressure process used in our Residual
Analysis, other processes include athmospheric
and split pressure
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Chemical Equations
Oxidization of Ammonia
NH3 1.25 O2 ? NO 1.5 H2O DH298K -226kJ/mol
Oxidization of Nitric Oxide
2NO O2 lt-gt 2NO2 DH298K -114kJ/mol
Absorbtion of Nitrogen Oxides Production of
Nitric Acid
3NO2(g) H2O(l) lt-gt 2HNO3(aq) NO(g) DH
-135.6 kJ/mol
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Oxidization of Ammonia
Ammonia Converter
Compressor
Air Filter
Air
Evaporator
NO (g)
Ammonia NH3 (g)
Warm Water Circulate
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Formation of Nitric Acid
Absorption Tower
Tail Gases
Heat Exchanger
Cold Water Circulate
NO2 (g)
Condenser
NO (g)
HNO3 (aq)
To Catalytic Combustor
Filtered Air
Bleacher
HNO3 (aq)
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Emissions
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Emissions
Absorption Towers used to reduce nitrous oxides
in the tail gas (NOx)
Catalytic Combustor used to convert nitrous
oxides to elemental nitrogen
Waste heat from processes is recycled for other
plant processes
Emissions can be reduced to under 200 ppm
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Calculations
NH3 1.25 O2 ? NO 1.5 H2O DH298K -226kJ/mol
2NO O2 lt-gt 2NO2 DH298K -114kJ/mol
3NO2(g) H2O(l) lt-gt 2HNO3(aq) NO(g) DH
-135.6 kJ/mol
Oxidation of Ammonia Ammonia (NH3) 202
tonnes/yr Oxygen (O2) 476 tonnes/yr Air (O2
N2) 2269 tonnes/yr Water (H2O) 321 tonnes/yr
Oxidation of Nitric Oxide Nitrous Oxide (NO)
357 tonnes/yr Oxygen (O2) 190 tonnes/yr Air (O2
N2) 907 tonnes/yr
Energy Compressor 521.1 GJ/yr (16.5kW) Waste
Heat Boiler 208.44 GJ/yr (6.6kW) Net 312.7
GJ/yr (9.9kW)
Absorption of Nitrogen Oxides Nitrous Oxide
(NO) 119 tonnes/yr Nitrogen Dioxide (NO2) 548
tonnes/yr Water (H2O) 71 tonnes/yr Nitric Acid
(HNO3) 500 tonnes/yr
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Conclusion
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References
1 Nitric Acid