Description:
<jats:title>Abstract</jats:title><jats:p>A new stage‐to‐stage method has been developed for the calculation of NX<jats:sub>x</jats:sub> absorption columns. Each stage of the absorption column is simulated as a combination of a bubble column reactor (absorption) and an adiabatic plug for reactor (oxidation). The bubble column reactor is modelled as two single stirred tank reactors, one as a gas‐phase and one as a liquid‐phase reactor, both coupled by mass and heat transfer. In this hydrodynamic model, a dynamic approach is adopted, in which the gas‐phase transport of N<jats:sub>2</jats:sub>O<jats:sub>4</jats:sub> is the limiting step for the absorption. A gas‐phasepseudo‐enhancement for factor for N<jats:sub>2</jats:sub>O<jats:sub>4</jats:sub> is therefore introduced. The balance equations for a single phase of the bubble column are solved with a Newton‐Raphson algorithm. The entire column calculation is divided into a gas and a liquid side. On both sides, the stage‐to‐stage method is applied in such way that the overall calculation is performed as a loop process. The direction of the loop calculation follows that of the flow: gas‐side upwards and liquid‐side downwards.</jats:p>