Operability Analysis and Control Design of an IRCC HMR Unit with Membrane Leakage

This paper describes an operability analysis and control structure design for handling membrane leakage in a hydrogen membrane reactor (HMR) as used in an integrated reforming combined power cycle (IRCC) based on natural gas as fuel. For this type of reforming to be competitive to power generation with carbon capture, low costs and emission of CO₂ and NO_x is required. Further, high operability and robustness is also required. This is achieved through an understanding of the system dynamics and robust control structure design.

The overall aim of the work is to improve the operability of such gas power plants under membrane leakage, which may cause detrimental hot areas in the reactor. Good operability means essentially that a plant can be operated easily, i.e. it can cope with disturbances, offsets and other uncertainties with the smallest possible profit loss and without frequent shutdowns. This is obtained both through design of the process itself and design of the control system. An important ingredient is the use of a dynamic, control relevant simulation model. The paper presents an analysis of how the control objective affects the choice of control structure for the HMR process and the control performance under membrane leakage. Also, the effect on CO₂ capture is shown.