Towards demand-side management of the chlor-alkali electrolysis: Dynamic modeling and model validation

•Formulation of a dynamic model of a real chlor-alkali electrolysis plant.•All phenomena relevant for dynamic operation are included.•All variables relevant for obtaining optimal control trajectories are described.•Comparison of model results with real plant data shows very good agreement. The chlor-alkali electrolysis promises advantageous application of demand-side management and several research groups have proposed dynamic models to obtain optimal trajectories for such applications. However, no dynamic model of those proposed so far has yet been validated with real, industrial plant data. This is highly important to determine trajectories, which are indeed feasible. This contribution addresses this issue by proposing a dynamic model of the chlor-alkali electrolysis that contains those variables relevant for dynamic operation, especially temperature and composition of the electrolytes. This model is validated with real plant data from an electrolysis located in Marl, Germany, for two scenarios: (1) several small load changes of around 4 MW and (2) a large load change of more than 50 MW.