1. 1 NITRIC ACID PLANT (63% wt. HNO 3 ) Ammonia-Based Fertilizers University of Illinois at Chicago Department of Chemical Engineering CHE 397 Senior Design II February 14, 2012 Thomas Calabrese (Team Leader) Cory Listner Hakan Somuncu David Sonna Kelly Zenger (Scribe)

2. 2 Today’s Agenda  Recap of Questions from the First Meeting  Assumptions and Revised Block Flow Diagram  Overall Material Balance  Flow Sheet (Excel Document)  Reactor Sample Calculation  Partial Energy Balance  Compressor Sample Calculation  Rough Economics  Reactants and Products  Equipment Costs  Staffing  Data References

3. 3 Revisiting Last Session’s Questions Azeotrope of HNO 3 and H 2 O = 68% w/w  Solution made is 63% w/w  Significance of azerotropic point for absorption differs from distillation Examples of plants using cobalt oxide  JRS Brandon Plant Manufacturing Complex Simplot Canada Ltd. Brandon, Manitoba Canada  Incitec (Pivot) Australia Girdler Plant Kooragang Island, Australia

4. 4 Material Balance Assumptions Liquid ammonia is pure Water vapor and other trace gases in air are negligible Ammonia/Air mixture is 11% v/v 96% reactor efficiency All water formed in the reactor is condensed at the cooler- condenser Trace gases ignored in 45% w/w HNO 3 solution after condenser Percent composition of oxygen in tail gas of absorption column is 2.5% Impurities in HNO 3 are negligible at bleacher

5. 5 Revised Block Flow Diagram

6. Excerpt from Flow Sheet 6 Stream NameNH3-LIQNH3-VAP1NH3-VAP2AIRCOMP-AIRPRIM-AIRSEC-AIRREACTOR-INREACTOR-OUT Temperature °F -287726660462 432752 Pressure psi145 14.7145 Mass Flow TOTAL tons/day NH3593.73 0.00 593.730.00 NO0.00 1,004.35 NO20.00 N2O0.00 3.84 N20.00 7,935.69 7,013.69922.007,013.697,030.78 O20.00 2,409.69 2,129.72279.972,129.72756.18 H2O0.00 942.06 HNO30.00

7. 7 Overall Material Balance Element Balance lbmol/dayReactor INReactor OUTCondenser INCondenser OUTAbsorber INAbsorber OUT N1,071,199 1,202,851 O266,215 365,609 H209,169 337,964 Overall TPDINOUTErrorError % Reactor9,737 00.00 Condenser9,737 00.00 Absorber11,519 00.00 Plant11,519 00.00

8. 8 Sample Calculation: Reactor [1] 4NH 3 (g) + 5O 2 (g)  4NO (g) + 6H 2 O (g) 96% [2] 4NH 3 (g) + 3O 2 (g)  2N 2 (g) + 6H 2 O (g) 3.5% [3] 4NH 3 (g) + 4O 2 (g)  2N 2 O (g) + 6H 2 O (g) 0.5% Basis: 100 lbmol NH 3  NO Produced in Reaction [1]: (100 lbmol NH 3 )*(4 lbmol NO / 4 lbmol NH 3 )*0.96 = 96 lbmol NO  N 2 Produced in Reaction [2]: (100 lbmol NH 3 )*(2 lbmol N 2 / 4 lbmol NH 3 )*0.035 = 1.75 lbmol N 2  N 2 O Produced in Reaction [3]: (100 lbmol NH 3 )*(2 lbmol N 2 O / 4 lbmol NH 3 )*.005 = 0.25 lbmol N 2 O  O 2 Required from Reaction [1]: (98 lbmol NO)*(5 lbmol O 2 / 4 lbmol NO) = 120 lbmol O 2  O 2 Required from Reaction [2]: (0.88 lbmol N 2 )*(3 lbmol O 2 / 2 lbmol N 2 ) = 2.63 lbmol O 2  O 2 Required from Reaction [3]: (0.13 lbmol N 2 O)*(4 lbmol O 2 / 2 lbmol N 2 O) = 0.50 lbmol O 2  Total O 2 Required: (120 + 2.63 + 0.50) = 123.13 lbmol O 2  H 2 O Produced in Reaction [1]: (120 lbmol O 2 )*(6 lbmol H 2 O / 5 lbmol O 2 ) = 144 lbmol H 2 O  H 2 O Produced in Reaction [2]: (2.63 lbmol O 2 )*(6 lbmol H 2 O / 3 lbmol O 2 ) = 5.25 lbmol H 2 O  H 2 O Produced in Reaction [3]: (0.50 lbmol O 2 )*(6 lbmol H 2 O / 4 lbmol O 2 ) = 0.75 lbmol H 2 O  Total H 2 O Produced: (144 + 5.25 + 0.75) = 150.00 lbmol H 2 O  Air Supplied to Reactor: (100 lbmol NH 3 ) / 0.11 = 909.09 lbmol  O 2 Supplied to Reactor: (909.09 lbmol)*0.21 = 190.91 lbmol O 2  N 2 Supplied to Reactor: (909.09 lbmol)*079 = 718.18 lbmol N 2  Unreacted O 2 : 190.91 – 123.13 = 67.78 lbmol O 2  Unreacted N 2 : 718.18 + 1.75 = 719.93 lbmol N 2

9. Partial Energy Balance 9 EquipmentEnergy Load [Btu/hr] Ammonia Evaporator33,834,047 Ammonia Preheater11,743,705 Compressor130,743,163 Comp. Intercooler60,850,132

10. 10 Sample Calculation: Compressor Where: W = Work [Btu/lbmol] Z = Compressibility Factor R = Gas Constant [Btu/lbmol-R] T 1 = Inlet Temperature [R] T 2 = Outlet Temperature [R] P 1 = Inlet Pressure [psi] P 2 = Outlet Pressure [psi] P i = Interstage Pressure [psi] E p = Compressor Efficiency

11. 11 Sample Calculation: Compressor Sample Calculation based on 100 lbmol NH 3 requirements and will be scaled up to show actual energy input. Inlet Air Temperature = 59 F = 518.67 R Inlet Pressure = 14.7 psia Outlet Pressure = 159.7 psia We will to use a multi-stage centrifugal compressor with an intercooler: 2-stage compressor with equal work in each stage and an efficiency of 76%

12. 12 Sample Calculation: Compressor Scaling to actual process requirements: 130,743,163 Btu/hr

13. 13 Rough Economics

14. 14 Rough Economics

15. 15 Looking Ahead Flow Sheeting Energy Sinks/Loads Equipment Sizing  Must first complete energy balance  Flow rates of cooling and boiler feed water will need to be known. Costing ASPEN Process Estimator

16. 16 References for Data Ullman’s Encyclopedia of Industrial Chemistry. Volume A17. VCH. Towler, Gavin. Chemical Engineering Design. 2008. Perry, Robert and Don Green. Perry’s Chemical Engineers’ Handbook 8 th Edition. McGraw-Hill 2008. Felder, Richard and Ronald Rousseau. Elementary Principles of Chemical Processes 3 rd Edition. John Wiley & Sons Inc. 2005. Maurer, Rainer and Uwe Bartsch. Krupp Uhde Nitric Acid Technology. 2001..

17. 17 Questions?