Ammonia in water - example of adiabatic decompression from an elevated pressure and temperature.

This example:

In the [Reactants Window] there are 2 reactants (Inflows):

      99 H2O +  1 NH3 = 
OLI options in effect: - none - .

In the [Menu Window] the product temperature is not specified - it will be calculated. Since temperature is the target variable an estimate of its value is specified in the target frame, for example 50 C. This estimate is not important in OLI calculations which are limited to the range -50 to +300 C. It is only meaningful for situations where the product temperature could be several hundreds or possibly thousands of degrees.

The product pressure is 1 atm and the product enthalpy, H(J) = -2.38481E+07. The enthalpy value was obtained from a prior single equilibrium calculation at 10 atm and 200 C. In the present example, this value of enthapy is fixed and so the calculation represents adiabatic decompression from 200 C and 10 atm.

All data are taken from OLIP (Public.ddb) - the OLI Systems public databank. For this example to work both FactSage and the OLI StreamAnalyzer must be installed on the PC, and the OLIP (Public.ddb) databank must included in the list of databases.

After calculating the equilibria the product temperature is 99.80 C.

For a range of pressures, return to the [Menu Window] and enter '0.25 10 0.25' i.e. P = 0.25, 0.50, 0.75 .. 10 atm (40 values).

Repeat the calculation (this may take several minutes). In the [Results Window] there should be 40 pages of results:


---------------------------------------------------------------------------- FactSage results at 1 atm for adiabatic decompression from 200 C and 10 atm. OLI options in effect: - none - ---------------------------------------------------------------------------- [FACT Format] 99 H2O + NH3 = 97.937 mol ( 0.98981 H2OVAP + 0.10195E-01 H3N_NH3VAP) ( 99.80 C, 1 atm, gas_OLI) + 0.37146E-01 mol ( 55.508 H2O + 0.40722E-01 H3N_NH3AQ + 0.78163E-03 HO[-1]_OHION + 0.78162E-03 H4N[+1]_NH4ION + 0.75591E-09 H[+1]_HION) ( 99.80 C, 1 atm, aqu_OLI) **************************************************************** H G V S Cp (J) (J) (l) (J/K) (J/K) **************************************************************** -2.38481E+07 -3.10804E+07 2.97210E+03 1.93918E+04 3.23382E+03 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [ChemSage Format] *T = 99.80 C P = 1.00000E+00 atm V = 2.97210E+03 dm3 STREAM CONSTITUENTS AMOUNT/mol H2OVAP/gas_OLI/ 9.9000E+01 H3N_NH3VAP/gas_OLI/ 1.0000E+00 EQUIL AMOUNT MOLE FRACTION FUGACITY PHASE: gas_OLI mol atm H2OVAP 9.6938E+01 9.8981E-01 9.6872E-01 H3N_NH3VAP 9.9846E-01 1.0195E-02 1.0001E-02 TOTAL: 9.7937E+01 1.0000E+00 1.0000E+00 PHASE: aqu_OLI mol MOLALITY ACTIVITY H2O 2.0619E+00 5.5508E+01 9.9924E-01 H3N_NH3AQ 1.5127E-03 4.0723E-02 4.0750E-02 HO[-1]_OHION 2.9034E-05 7.8163E-04 7.5321E-04 H4N[+1]_NH4ION 2.9034E-05 7.8163E-04 7.5321E-04 H[+1]_HION 2.8079E-11 7.5591E-10 7.2822E-10 TOTAL: 2.0635E+00 1.0000E+00 ******************************************************************** Cp_EQUIL H_EQUIL S_EQUIL G_EQUIL V_EQUIL J.K-1 J J.K-1 J dm3 ******************************************************************** 3.23382E+03 -2.38481E+07 1.93918E+04 -3.10804E+07 2.97210E+03 Properties for aqu_OLI: pH = 9.1377 Total solute molality = 0.0423 Ionic strength = 0.0008 Osmotic coefficient = 1.0000 Debye-Hueckel slope = 0.4603 Density/mol.dm-3 = 53.1945 Absolute viscosity/cP = 0.2816 Mole fraction of system components: gas_OLI aqu_OLI H(+1) 6.6780E-01 6.6675E-01 N(-3) 3.3868E-03 2.4899E-04 O(-2) 3.2882E-01 3.3300E-01 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [OLI StreamAnalyzer - Summary of Results] Calculation Summary SinglePoint1 Calculation for Work1 Automatic Chemistry Model Databanks: Public Unit Set: Default Isenthalpic Calculation Enthalpy -2.38481e7 J Pressure 1.0000 atm Temperature 99.8031 °C Stream Inflows Water 99.000 mol Ammonia 1.0000 mol Speciation Summary Total number of species: 10 User Related Aqueous Inflows Inflows Species H2O NH4OH H2O NH3 NH3 - Aq NH3 - Vap NH4+1 H+1 OH-1 Stream Parameters Stream Amt 100.00 mol Temperature 99.8031 °C Pressure 1.0000 atm pH 9.1390 pH Total Aqueous Vapor J J J Enthalpy -2.3848e7 -7.3688e5 -2.3111e7 Species Output (True Species) Total Aqueous Vapor mol mol mol H2O 99.000 2.6294 96.371 NH3 0.99996 1.9394e-3 0.99802 NH4+1 3.7120e-5 3.7120e-5 0.0 H+1 3.5705e-11 3.5705e-11 0.0 OH-1 3.7120e-5 3.7120e-5 0.0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~