Welcome to the Process NMR Associates Network NMR Application - Fluid Catalytic Cracking Control and Optimization [View Application Note PDF] The fluid catalytic cracking unit (FCCU) is one of the most important units in the refinery. Few FCCUs have real-time process optimization implemented, since feeds typically have been measurable only in the laboratory. These measurements take many hours, with reports available only once or twice a day. Even the measurement of PIONA (paraffins, isoparaffins, olefins, naphthenes, and aromatics) and the distillation properties of the rundowns are difficult to achieve on-line. The Donahue Process Systems NMR now provides a means of obtaining these measurements near real-time, thus enabling significant economic benefit to the refiner through APC and process optimization.