Magnetic actuation of functional microparticles for mass transfer enhancement.

Duration: 01.02.2012 - 01.10.2015

Sponsor: ERC

Ph.D student: Philip Lisk

Dr. Erell Bonnot

Dr. Taifur Rahman

Professor Robert Bowman

Catalytic processes in the liquid phase are crucial in the manufacturing of high value fine and specialty chemicals. By avoiding mass-transfer limitations, the use of very small catalyst particles (1–5 μm) suspended in a liquid could greatly enhance the efficiency of the catalytic process. However, the difficulties in recovering small particles from the reaction mixture severely limit their use in industrial applications because unrecovered small particles can lead to blocking of filters and valves in chemical plants. To overcome the above drawbacks, the separation of suspended magnetic catalyst bodies from the liquid system using an external magnetic field is a promising strategy. Furthermore magnetic microparticles can be oscillated improving local mixing and mass transfer in the reactor. Under the influence of a low frequency magnetic field, a magnetic material tries to rotate as a whole in order to achieve the position of lowest energy. A concept is proposed in which catalytic microparticles are moved to "scan" the fluid. Scanning of the fluid is obtained by giving the particles a prescribed motion which is enabled by superposing a time-varying magnetic field.