TY  - JOUR
A1  - Haene, Janick
A1  - Bruehwiler, Dominik
A1  - Ecker, Achim
A1  - Hass, Roland
T1  - Real-time inline monitoring of zeolite synthesis by Photon Density Wave spectroscopy
JF  - Microporous and mesoporous materials : zeolites, clays, carbons and related materials
N2  - The formation process of zeolite A (Linde Type A) was monitored inline at 1.5 L scale by Photon Density Wave (PDW) spectroscopy as novel process analytical technology for highly turbid liquid suspensions. As a result, the reduced scattering coefficient, being a measure for particle number, size, and morphology, provides distinct process information, including the formation of amorphous particles and their transfer into crystalline zeolite structures. The onset and end of the crystallization process can be detected inline and in real-time. Analyses by powder X-ray diffraction and electron microscopy, based on a sampling approach, support the interpretation of the results obtained by PDW spectroscopy. In addition, the influence of the molar water content was investigated, indicating a linear increase of the time needed to reach the end of the zeolite A crystallization with increasing molar water content. Further experiments indicate a strong influence of the silica source on the course of the crystallization. The applicability of PDW spectroscopy under even more demanding chemical and physical conditions was investigated by monitoring the synthesis of zeolite L (Linde Type L).
KW  - Photon density wave spectroscopy
KW  - Process analytical technology
KW  - Zeolite synthesis
KW  - Molar water content
KW  - Silica source
Y1  - 2019
U6  - https://doi.org/10.1016/j.micromeso.2019.109580
SN  - 1387-1811
SN  - 1873-3093
VL  - 288
PB  - Elsevier
CY  - Amsterdam
ER  -