A Simulation Study on Dynamics and Control of a Refrigerated Gas Plant

Natural gas has recently emerged as an important source of clean energy. Improving operational efficiency of a gas processing plant (GPP) may significantly increase its profit margin. This proves to be a challenging problem due to the time-varying nature of the feedstock compositions and business scenarios. Such fluctuations in operational and economic conditions are handled by employing advanced process control (APC). Reasonably accurate steady-state and dynamic simulation models of the actual plant are required for the effective implementation of APC. This paper deals with the development of such models. Here, a refrigerated gas plant (RGP), which is the low temperature separation unit (LTSU) of the GPP, is modeled under HYSYS environment. Calibration and validation of the steady-state model of the RGP are performed based on the actual plant data. A dynamic model is also built to act as a virtual plant. Main control philosophies of the virtual plant are reported in this paper. This virtual plant model serves as a platform for performing APC studies.