Advanced instrumentation and control improve refiners' profitability

This paper reviews major projects designed to upgrade and consolidate the control systems of several U.S. refineries. In each project existing pneumatic and analog instrumentation was replaced with Honeywell's TDC-2000 digital instrumentation and further enhanced with a TDC-4500 process control computer with PMX control software. In the initial conception and justification of the project, configuration of the control system, and successful implementation of advanced controls were considered. This paper discusses the principles employed and the approach developed. It also describes several specific examples from the projects, including conversion controls on a hydrocracker, methane refrigerant inventory controls in the cold section of an ethylene recovery and fractionation unit, and pump around controls on a fluid catalytic cracker unit main fractionator.