Pre-neutralizer (MAP/DAP) simulation

acid (phosphoric acid + scrubber liquors) + ammonia -> slurry, vapor, excess ammonia

Governing equations

The exact equations the solver works for a pre-neutralizer (map/dap) — the same math shown in the app's "Theory" panel, not a black box.

$MR$

ammonia : phosphoric acid mole ratio after sulfate [-]

$N$

ammonia nitrogen [mol/s]

$P$

phosphorus [mol/s]

$S$

sulfur [mol/s]

$s$

ammonia slip, fraction of the ammonia fed leaving unreacted [-]

$F_{NH_3,react}$

ammonia reacted [mol/s]

$F_{NH_3,fed}$

ammonia drawn [mol/s]

$F_{NH_3,in}$

ammonia arriving in the acid (scrubber liquor) [mol/s]

$w_{H_2O}$

water mass fraction kept in the slurry [-]

$m_{H_2O,slurry}$

water in the slurry [kg/s]

$m_{slurry}$

slurry mass [kg/s]

$F$

molar flow [mol/s]

$h$

molar enthalpy, elements at 298.15 K [J/mol]

$Q$

duty to hold the temperature [W]

Parameters

phosphoric acid neutralised by ammonia to a mole ratio (N/P after the sulfate's ammonium sulfate). Components: phosphoric_acid, sulfuric_acid, water, ammonia, monoammonium_phosphate, diammonium_phosphate, ammonium_sulfate, phosphate_impurities (inert lump). mole_ratio [-] (required, <= 2); temperature [K] (required, the slurry's); pressure [Pa] (default the lowest acid inlet's); slurry_water_fraction [-] (required: mass fraction of water kept in the slurry, a plant measurement -- no solubility data is held here); ammonia_slip [-] (required: fraction of the ammonia fed that leaves unreacted, measured). Reaction heat follows from NBS 1982 formation enthalpies; the duty to hold the temperature is reported (negative: surplus heat)

Example flowsheets that use it