Magnetic resonance imaging in chemical and bioprocess engineering

Material transport, temperature distributions and chemical composition are critical system parameters that need to be controlled within chemical and biological reactor systems. However, due to the opaque nature of most materials and media involved, it is challenging to image these parameters with spatial and temporal resolution within reactors. Among the tomographic techniques applicable, MRI offers by far the largest variety of relevant system properties it can measure, such as local density, flow, diffusion, temperature, and chemical compositions and reactions.

The Institute of Process Imaging (IPI) focuses on MRI of complex multi-phase and reactive systems. The majority of systems under investigation are gas-solid, gas-liquid and gas-liquid-solid systems. The unique MRI system at the IPI allows for investigation of samples up to a diameter of 40 cm and a height of up to two meters. The systems have to be non-magnetic and ideally non-conductive. Materials as well as reactors can be investigated. Typical reactor types include fluidized and spouted beds, bubble column reactors, and pipe reactors.

Furthermore, the IPI is developing and applying magnetic resonance methods to enable access to these critical parameters. A major challenge is the spatial and especially temporal resolution as well as access to complex process parameters. These efforts include: 

  • Manufacturing of modern MRI hardware, such as detector arrays or microcoils, leading to significant improvements in image quality.
  • Pulse sequence design aimed at speed and reliability, which can increase temporal resolution to levels needed for highly dynamic processes.
  • Synthesis of MRI contrast agents, also for granular media, for increased image quality.
  • Development of powerful image reconstruction algorithms and
  • Automated image processing and analysis breaking down information to process relevant parameters, employing among others computer vision and machine learning approaches.

The IPI collaborates with many institutes within the TUHH, but also with researchers at ETH Zürich, Columbia University and Osaka University.