This model simulates the causticising reaction of green liquor with slaked lime. The reversible causticising reaction can be represented by, Ca(OH)2 + Na2CO3 <-----> CaCO3 + 2NaOH The model calculates the extent of reaction and the resulting changes in outlet stream composition. What do you want to see? Data Description Equipment Properties Example Method&Equations Warnings Errors

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Data Descriptions

Equipment Properties

Example of using equipment

Method&Equations

The extent of reaction is computed from a model similar to the one presented in [1]. The causticiser is assumed to be an ideal CSTR in which case the following equation applies.
    V/F0 = X/Rc
where, the rate of causticising, Rc is given by the kinetic model in [1],
    Rc = k1( [NaCO3]0 (1-X) )a - k2(EA0+X [NaCO3]0 )b
    k1 = Rf exp (-29.0/RT + 4.25)
    k2 = exp (-25.6/RT - 8.3)
    a = 1.0
    b = 3.0
Nomenclature
    V Volume of the CSTR
    F0 Molar feed rate of sodium carbonate
    X Fractional conversion of sodium carbonate
    Rc Rate of causticising
    [NaCO3]0 Initial sodium carbonate concentration g/l as Na2O
    EA0 Initial Efffective alkali g/l as Na2O
    R Gas constant
    T Absolute temperature
    Rf Rate of forward reaction (user specified, default = 1.0)
The exit conversion X is calculated iteratively from the above equations.

Warnings

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Errors

Missing Stream(s)!

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