3D-Printed Zeolitic Imidazolate Framework Structures for Adsorptive Separations

We report the use of a 3D-printing fiber deposition method to synthesize ZIF-8 monoliths. A binder recipe was developed containing 16.7 wt % of methylcellulose and 16.7 wt % of bentonite binder. The effect of the used binders on the adsorption of n-butanol and Ar was investigated, showing a decrease in equilibrium loading of 33 wt % for n-butanol due to the presence of both binders. To maximally recover the adsorption capacity, a thermal activation procedure was developed to remove the organic binder after 3D-printing without destroying the ZIF-8 structure. The use of different activation temperatures for the removal of the organic binder was investigated, showing activation at 450 degrees C to be optimal. Adsorbent monoliths using a nozzle with two different diameters (250 and 600 mu m) were subsequently printed and the efficacy of the monoliths for the recovery of biobutanol was tested via breakthrough experiments. The developed structures showed to retain the selectivity of ZIF-8 for biobutanol, adsorbing 0.2 g/g n-butanol in dynamic conditions, opening perspectives for the further design and optimization of 3D-printed ZIF-8 structures.