Why is Inline NMR Rarely Used as Industrial Sensor? Challenges and Opportunities

Although nuclear magnetic resonance (NMR) is one of the most powerful analytical techniques, it has not been widely used as a non‐destructive, non‐contact inline industrial sensor. A short background of NMR spectroscopy fundamentals and instrumentation is presented along with its potential applications and limitations for real‐time analysis in the manufacturing sector. NMR signals are generated in the presence of a magnetic field normally produced by expensive large and heavy magnets which have been the major limiting factor in the use of NMR analysis in factories. However, the last decade has brought substantial advances in the development of cheaper, smaller, and lighter permanent magnets based on rare earth materials that use Halbach and unilateral configurations. Small and light cryogenic‐free superconducting magnets are now offered in the market and are opening a new era in manufacturing. It is expected that soon NMR spectroscopy will be applied to monitor the chemical and physical properties of complex feedstock mixtures and reactions in real time which is the ultimate goal of precise process control. Current inline NMR developments will soon provide a cost‐effective industrial NMR sensor for precise real‐time monitoring of chemical and physical properties of complex feedstock mixtures and reactions. NMR spectroscopy fundamentals and instrumentation are reviewed together with potential applications and limitations for real‐time analysis in the manufacturing area.