Fabrication and characterisation of hydrophobic coatings for metallic membranes for the gas/liquid phase separation in a micro structured device
Bachelor's / Master's Thesis
Background and motivation
The reaction to produce some sugar derivatives is a reversible reaction that can be conducted with a high yield and selectivity in micro reactors at high temperatures. By removing water from the reaction mixture, the equilibrium of the reaction can be shifted towards higher conversion. Previous investigations showed that the reaction can be run using a two-stage micro reactor process that includes an operation for water separation in-between.
Within a technology transfer project in cooperation with an international industry partner, the development of a novel membrane technology for the continuous removal of water during the reaction is pursued. The use of membrane reactor technology may enable to combine both unit operations (chemical reaction and membrane filtration) into one device and therefore perform the process in one-step. This will reduce further equipment and increase the energy efficiency of the process.
PMM Medium Pall Corporation before coating PE-CVD Plant at IMVT
The membrane in the membrane reactor should withstand thermally, mechanically and chemically the reaction conditions. Hence, novel materials and technologies are required for the separation of water at the desired reaction conditions.
The water should be separated in gaseous state through the pores. Due to the required high temperature conditions, porous metallic membranes are considered. The main challenge here is on the one hand the high surface energy of metallic membranes (hydrophilic behaviour) and on the other hand the surface tension of the reaction fluid and its temperature and pressure dependence. These facts lead to the wetting of the pores even for low pressure differences between feed and permeate side of the membrane. By means of specific hydrophobic coatings, the liquid penetration can be prevented.
Topic and Tasks of the Thesis
In order to use a membrane at the reaction conditions (high temperatures) novel membrane materials are needed which are hydrophobized. At the IMVT the Plasma Enhanced –Chemical Vapour Deposition process is available for the hydrophobization experiments.
The aim of this work is to produce and characterize hydrophobic coatings for metallic membranes.
The individual tasks include:
- Determination and evaluation of suitable coating materials based on a literature study.
- Production of coatings with a PVD/CVD coating system.
- Characterisation of the coatings: analysis of the coating at the inner surface of the pores by SEM, determination of the contact angle, determination of coating thickness, etc.
- Students of Chemical Engineering / Process engineering / Chemistry
- Knowledge in chemical engineering required, background in material science welcome
- The results of the work will be presented at the institute seminar.
- The thesis can be written in English or in German
- Start: by arrangement
Examiner: Prof. Dr.-Ing. Roland Dittmeyer
Supervisor: Sara Claramunt
Contact: firstname.lastname@example.org Tel: 0721/608-24052