Design and Implementation of Multivariable Control System in Refinery

Abstract

In a high margin environment, it is essential for refiners to take advantage of the favourable economic conditions while achieving reliable operations at maximum throughput. While the processes & systems are getting complex, higher-performance catalysts have been studied, Advance Control Systems that can handle ever-restricting multivariable reaction conditions have also been sought. Advanced Process Control (APC) systems are applied almost universally on major process units to identify the optimum operating point and to maintain stable operations within multiple constraints. The purpose of advanced process control (APC) is to improve profitability by applying strategies which coordinate the regulatory control systems on the plant. APC benefits come from smoother operation of plants (reducing impacts of process disturbances) and providing consistent operation at optimal constraints. The objective of the present work is to describe the application of Advanced Multivariable Control System on Diesel Hydrotreater unit of IOCL, Panipat Refinery, Panipat and compares its performance to the previous conventional control system. The purpose of multivariable controller is to provide a control on Diesel quality, minimization of power loss by recovering more power and maximization of throughput while operating within all constraints and hence achieve economic benefits from the smoother operation of the plant.