Imaging of copper oxygenation reactions in a bubble flow

Abstract

Reactions of gases with liquids play a crucial role in the production of many bulk chemicals. Often, the gas is bubbled into the chosen reactor. Most of the processes at the gas-liquid interface of the bubbles and in their tails are not fully understood and warrant further investigation. For this purpose, NMR imaging or Magnetic Resonance Imaging has been applied to visualize some of the processes in the bubble tail. To generate sufficient contrast, a magnetogenic gas-liquid reaction associated with a change of magnetic state, from diamagnetic to paramagnetic, was employed. In this work, a copper(I)-based compound was oxidized to copper(II) to exploit relaxation contrast. To match the speed of the rising bubbles to the acquisition time of the spin-echo imaging sequence, polyethylene glycol was added to increase the viscosity of the reacting solution. Images of the oxygen ingress into a static solution as well as of oxygen bubbles rising in the solution are presented. In both cases, changes in magnetism were observed, which reported the hydrodynamic processes.

Magnetic Resonance Imaging for Non‐invasive Study of Hydrodynamics Inside Gas‐Liquid Taylor Flows

“…Recently, Benders et al. 29 have visualized a chemical reaction in a highly viscous gas‐liquid flow by utilizing a contrast agent that shortened the relaxation times after contact with oxygen.…”

Elucidating the ionic liquid distribution in monolithic SILP hydroformylation catalysts by magnetic resonance imaging

“…Accordingly, MRI has been used for the examination of a wide range of both, so and hard materials such as polymers, food, plants and wood [18][19][20][21][22] as well as in a range of chemical engineering applications 23 including the characterization of ow in different geometries [24][25][26][27][28][29][30] and reactive systems. [31][32][33] NMR relaxation as the primary contrast parameter differs considerably for liquids in bulk and pores, 34 and many studies have investigated the distribution and evaporation of liquids in rocks and soil by MRI. [35][36][37] Similarly, MRI has been used to localize gas and liquid ows through monoliths.…”