Non-linear Modelling and Validation of an Industrial Methane Rich Gas Network for Control Applications

A non-linear first principle model of an industrial methane rich gas (MRG) network for a large petrochemical plant is developed in this paper. The model is validated against industrial plant data. The non-linearity of gas compressibility, which is sensitive to changes in pressure, composition and temperature, is a challenge for the control of such a network. This model addresses these non-linearities, and is validated with industrial plant data. Each subsystem in the network is modelled separately, and includes models for the pipe segments, gas compressibility, pipe friction factor and gas viscosity. A first principle non-linear model of the system will assist the design of supervisory and optimisation controllers which remain relevant over a large operating region.