Detailed Insight into Microscopic Phenomena Using 3D-Tomography Data to Develop a Better Model for Dead-End Filtration

Author Last Name: 
Peuker
Authors: 
M. Mohammadfoghi, E. Loewer, T. Leissner, U. A. Peuker
Report Type: 
ARR
Research Area: 
Wet Systems
Publication Year: 
2018
Publication Month: 
12
Country: 
Germany

Executive Summary
Due to the complexity of the parameters affecting the cake filtration process, we do a
comprehensive research by producing and interpreting laboratorial and micro-CT data.
This study was done on two main particle shapes, which generated different filter cake
characteristics.
In order to analyse the effect of particle shape on the filter cake structure and filtration
progress, we applied compact and needle-like particles. The needle-like particles showed
a fibrous behaviour when creation the filter cake structure. For the needle-like particles,
we selected Wollastonite, which is widely used in ceramics, friction products, painting
filler and plastics. In the case of compact particles, we selected Al2O3 T60/46 alphaalumina
sample. The material selection also was influenced by the specifications of the Xray
measurements, thus the solids need to have a certain X-ray adsorption as well as a
certain size range to fit to the voxel size of the measurements.
Particle-particle interaction during the filtration process was another scope of focus. To
analyse the overall effect of wettability change in our system, which plays an essential role
in particle-particle interaction, we defined two main filtration scenarios (for each particle
shape two scenarios). The first approach is to change the composition of the mother liquid,
in which we change the wetting properties by changing the ethanol concentration in the
solution. The second one is the modification of the particle surface. For this case, we do a
(wet) coating with highly hydrophobic silanes. Even though this is a quite time consuming
method, it delivers precise and reproducible surface properties for the scientific
investigations.
The actual state of the project is that the methods have been developed and the concept is
proven:
- Formation of filter cakes with different prose structure due to wetting effects.
- Selection of compact and needle-shaped particle system
- Generation (proof. of concept) of tomography images of filter cakes
- Image analysis of 3D-tomography data using VG Studio (expert software).
- Generation (proof of concept) of characteristic data of the pore system, e.g. pore
size distribution, capillary pressure distribution.