Patent ID: 8060258

Claim:
A multi variable process controller for controlling a catalyzed chemical reaction performed in a production unit including a reactor feed section and a chemical reactor comprising a plurality of pipes connected in parallel having inner surfaces affixed with at least one solid catalyst, said reactor implementing a process for forming a phthalic anhydride (PA) product, comprising: receiving controlled flows of reagents including at least one oxidizable substituted aromatic and an oxygen comprising source at an at least one inlet of said reactor: a CPU having a stored dynamic multi variable model for said process which represents the effects of moving a plurality of manipulated variables (MVs) comprising a flow of said oxygen comprising source gas and a flow or temperature of said oxidizable substituted aromatic on controlled variables (CVs) comprising a temperature at a plurality of positions along a length of said pipes: a plurality of inputs coupled to said CPU for receiving process information during said process comprising a first measured parameter related to performance of said catalyst in producing said PA product and a second measured parameter comprising said temperature at said plurality of positions, and and a plurality outputs driven by said CPU for sending control signals to adjust said temperature in said plurality of positions depending on at least said first measured parameter using said dynamic model.