Kinetics Study and Crystallization Process Design for Scale-Up of UiO-66-NH2 Synthesis

A comprehensive scale-up procedure for amine-functionalized UiO-66 is implemented, which leads to the development of a novel flow-through metal-organic framework synthesis process. Products are characterized via BET modeling of N-2 adsorption at 77 K and powder XRD to confirm crystal porosity and phase, respectively. Batch syntheses are conducted to examine the effects of polytetrafluoroethylene and glass vessel materials on crystal yield and quality. Intermediate samples from sealed-vessel trials at 373, 383, and 393 K are collected and characterized, which show a high degree of product consistency. Nucleation rates are determined at the same temperatures, and the Arrhenius relationship is used to predict the activation energy of nucleation, E-aNuc. A continuous-flow reactive crystallization process is developed using a draft-tube type reactor. As a proof of concept, the reactor is operated for three retention times. The cumulative product, material retained within the crystallizer, and intermediate samples are collected and characterized to confirm UiO-66-NH2 production. (C) 2012 American Institute of Chemical Engineers AIChE J, 59: 1255-1262, 2013