Abstract: A multivariable method and process controller is for controlling a catalyzed chemical reaction to form phthalic anhydride (PA), produced by a production unit including a chemical reactor having a plurality of pipes connected in parallel having inner surfaces affixed with at least one solid catalyst. The reactor implements a process for forming PA by receiving flows of reagents including at least one oxidizable substituted aromatic and an oxygen including source gas at one or more inlets of the reactor. A dynamic multivariable model for the process represents the effects of moving a plurality of manipulated variables (MVs) including a flow of the oxygen including source gas and a flow or temperature of the oxidizable substituted aromatic on controlled variables (CVs) including a temperature at a plurality of positions along a length of the pipes.

Abstract: A multivariable method and process controller is for controlling a catalyzed chemical reaction to form phthalic anhydride (PA), produced by a production unit including a chemical reactor having a plurality of pipes connected in parallel having inner surfaces affixed with at least one solid catalyst. The reactor implements a process for forming PA by receiving flows of reagents including at least one oxidizable substituted aromatic and an oxygen including source gas at one or more inlets of the reactor. A dynamic multivariable model for the process represents the effects of moving a plurality of manipulated variables (MVs) including a flow of the oxygen including source gas and a flow or temperature of the oxidizable substituted aromatic on controlled variables (CVs) including a temperature at a plurality of positions along a length of the pipes.