1. Residual Analysis of the Production of Nitric Acid Erik Tolonen Nick Poulin Environmental Engineering Environmental Planning and Decision Making ENVE4104

2. 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

3. Background: Nitric Acid among the 10 chemicals produced in the largest amounts Used for explosives, dyes and most importantly Fertilizers Unstable in its liquid form, decomposes quickly into nitrous oxides Completely miscible with water, mainly produced and used in its aqueous state High Pressure process used in our Residual Analysis, other processes include athmospheric and split pressure

4. Chemical Equations: NH 3 + 1.25 O 2  NO + 1.5 H 2 O  H 298K = -226kJ/mol Oxidization of Ammonia: 2NO + O2 2NO2  H 298K = -114kJ/mol Oxidization of Nitric Oxide: 3NO 2(g) + H 2 O (l) 2HNO 3(aq) + NO (g)  H = -135.6 kJ/mol Absorbtion of Nitrogen Oxides & Production of Nitric Acid:

5. Air Air Filter Ammonia NH 3 (g) Ammonia Converter NO (g) Warm Water Circulate Compressor Oxidization of Ammonia Evaporator

6. NO (g) Heat Exchanger NO 2 (g) Condenser Cold Water Circulate HNO 3 (aq) Bleacher HNO 3 (aq) Filtered Air Absorption Tower Formation of Nitric Acid Tail Gases To Catalytic Combustor

7. Catalytic Combustor Compressor Waste Heat Boiler Vent Tail Gases Emissions:

8. Absorption Towers used to reduce nitrous oxides in the tail gas (NO x ) 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

9. Calculations: Absorption of Nitrogen Oxides: Nitrous Oxide: (NO) 119 tonnes/yr Nitrogen Dioxide (NO 2 ) 548 tonnes/yr Water: (H 2 O) 71 tonnes/yr Nitric Acid: (HNO 3 ) 500 tonnes/yr 2NO + O2 2NO2  H 298K = -114kJ/mol NH 3 + 1.25 O 2  NO + 1.5 H 2 O  H 298K = -226kJ/mol 3NO 2(g) + H 2 O (l) 2HNO 3(aq) + NO (g)  H = -135.6 kJ/mol Oxidation of Nitric Oxide: Nitrous Oxide: (NO) 357 tonnes/yr Oxygen: (O2) 190 tonnes/yr Air: (O2 + N2) 907 tonnes/yr Oxidation of Ammonia: Ammonia: (NH3) 202 tonnes/yr Oxygen: (O2) 476 tonnes/yr Air: (O2 + N2) 2269 tonnes/yr Water: (H2O) 321 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)

10. Conclusion:

11. References: [1]Nitric Acid