TITLE Example 7.--Organic decomposition with fixed-pressure and
                  fixed-volume gas phases
SOLUTION_MASTER_SPECIES
N(-3)    NH4+           0.0     N
SOLUTION_SPECIES
NH4+ = NH3 + H+
        log_k           -9.252
        delta_h 12.48   kcal
        -analytic    0.6322    -0.001225     -2835.76

NO3- + 10 H+ + 8 e- = NH4+ + 3 H2O
        log_k           119.077
        delta_h -187.055        kcal
        -gamma    2.5000    0.0000
PHASES
NH3(g)
        NH3 = NH3
        log_k           1.770
        delta_h -8.170  kcal
SOLUTION 1
EQUILIBRIUM_PHASES 1
        Calcite
        CO2(g)  -1.5
SAVE solution 1
SELECTED_OUTPUT
        -reset false
        -file ex7.sel
        -simulation     true
        -state          true
        -reaction       true
        -si CO2(g) CH4(g) N2(g) NH3(g)
        -gas CO2(g) CH4(g) N2(g) NH3(g)
END
#  Simulation 2: Decomposition of organic matter, CH2O(NH3).07,
#  at fixed pressure of 1.1 atm
USE solution 1
GAS_PHASE 1 Fixed-pressure gas phase
        -fixed_pressure
        -pressure       1.1
        CO2(g)          0.0
        CH4(g)          0.0
        N2(g)           0.0
        H2O(g)          0.0
REACTION 1
        CH2O(NH3)0.07     1.0
        1. 2. 3. 4. 8. 16. 32 64. 125. 250. 500. 1000. mmol
USER_GRAPH 1 Example 7
        -headings Fixed_Pressure: CH4 CO2 N2 H2O #Volume
        -chart_title "Gas Composition"
        -axis_titles "Organic matter reacted, in millimoles" \
        	     "Log(Partial pressure, in atmospheres)" "Volume, in liters"
        -axis_scale x_axis 1 1e3 auto auto log
        -axis_scale y_axis -5.0 1.0 1 1
        -connect_simulations false
  -start
  10 IF GAS("CH4(g)") < 1e-10 THEN GOTO 100
  20 mM_OM = RXN * 1e3
  30 PLOT_XY -10, -10, line_width = 0, symbol_size = 0
  40 PLOT_XY mM_OM, SI("CH4(g)"), color = Black, symbol = XCross
  50 PLOT_XY mM_OM, SI("CO2(g)"), color = Red, symbol = XCross
  60 PLOT_XY mM_OM, SI("N2(g)"), color = Teal, symbol = XCross
  70 PLOT_XY mM_OM, SI("H2O(g)"), color = Blue, symbol = XCross
  100 REM end of program
  -end
USER_GRAPH 2 Example 7
        -headings  Fixed_P:...Pressure Fixed_P:...Volume
        -chart_title \
            "Total Gas Pressure and Volume"
        -axis_titles "Organic matter reacted, in millimoles" \
                     "Log(Pressure, in atmospheres)" "Volume, in liters"
        -axis_scale x_axis 1 1e3 auto auto log
        -axis_scale y_axis -5.0 1.0 1 1
        -axis_scale y2_axis 1e-3 1e5 auto auto log
        -connect_simulations false
  -start
  10 IF GAS("CH4(g)") < 1e-10 THEN GOTO 100
  20 mM_OM = RXN * 1e3
  30 moles = (GAS("CH4(g)") + GAS("CO2(g)") + GAS("N2(g)") + GAS("H2O(g)"))
  40 vol = moles * 0.08207 * TK / 1.1
  50 PLOT_XY mM_OM, LOG10(1.1), color = Magenta, symbol = XCross
  60 PLOT_XY mM_OM, vol, color = Cyan, symbol = XCross, y_axis = 2
  100 REM end of program
  -end
END
#  Simulation 3: Decomposition of organic matter, CH2O(NH3).07,
#  at fixed volume of 23.19 L
USE solution 1
USE reaction 1
GAS_PHASE 1 Fixed volume gas phase
        -fixed_volume
        -volume         23.19
        CO2(g)          0.0
        CH4(g)          0.0
        N2(g)           0.0
        H2O(g)          0.0
        -equilibrate 1
USER_GRAPH 1
        -headings Fixed_Volume: CH4 CO2 N2 H2O
  -start
  10 mM_OM = RXN * 1e3
  20 PLOT_XY -10, -10, line_width = 0, symbol_size = 0
  30 PLOT_XY mM_OM, SI("CH4(g)"), color = Black, symbol = Circle
  40 PLOT_XY mM_OM, SI("CO2(g)"), color = Red, symbol = Circle
  50 PLOT_XY mM_OM, SI("N2(g)"), color = Teal, symbol = Circle
  60 PLOT_XY mM_OM, SI("H2O(g)"), color = Blue, symbol = Circle, symbol_size = 5
  -end
USER_GRAPH 2
        -headings Fixed_V:...Pressure Fixed_V:...Volume
  -start
  10 mM_OM = RXN * 1e3
  20 tot_p = SR("CH4(g)") + SR("CO2(g)") + SR("N2(g)") + SR("H2O(g)")
  30 PLOT_XY mM_OM, LOG10(tot_p), color = Magenta, symbol = Circle
  40 PLOT_XY mM_OM, 23.19, color = Cyan, line_width = 1 symbol = Circle, y_axis = 2
  -end
END