Improved Offgas NOx Control on a Nitric Acid Plant Using DeltaV Multivariable Control

A multivariable predictive control solution was installed within the DeltaV control system at the Lovochemie KD5 Nitric Acid plant, catalytic NOx reduction system at Lovosice in the Czech Republic. The successful outcome of this project has been to control and reduce the NOx emissions in the plant tail gas, leading to a reduction in natural gas costs and reduced emissions.