Filtration and separation techniques are basic process operations. We show how these can be carried out with ceramics even in high-temperature processes and chemically aggressive environments.
Hall 7, Booth L36
Cologne
Messe Köln
Hall 7, Booth L36
February 14, 2023 - February 16, 2023
Hot gas filtration with ceramics
Cleanable ceramic filter media have proven themselves in hot gas cleaning at operating temperatures of 800 °C and above. Current projects deal with the hot gas dedusting of exhaust gases from the steel and lime industry in order to separate CO². The Fraunhofer IKTS has developed a new approach for this. By combining hot gas filtration with ceramic filters and CO² separation with nanoporous membranes, hot and dust-laden exhaust gases can be used for the first time to simultaneously recover CO² as raw material and recuperate heat.
Further new process developments at IKTS are aimed at the energy-efficient and selective separation of recyclable materials from hot gas processes by means of filtration. This allows phosphate-containing ashes to be recovered from the sewage sludge mono-combustion process and heavy metal to be removed at the same time. The concept is based on a modification of the ashes during combustion and the subsequent separation of the reaction products. The separation of the substances is carried out by hot gas filtration and uses the different volatilities of the reaction products formed.
Carbon membranes for the separation of H² or CO² from gas mixtures
Hydrogen is seen as a beacon of hope in the development of a CO²-free energy supply. Fraunhofer IKTS has developed a technology based on carbon membranes that can be used to efficiently separate hydrogen and natural gas. The membrane technology thus makes it possible to conduct the two substances together through the natural gas network and to separate them from each other as needed at the destination. Compared to pressure swing adsorption or cryogenic separation processes, this variant is cost-effective and resistant to harsh ambient conditions and natural gas by-products such as hydrogen sulfide. The membranes can concentate 5 vol% hydrogen in the feed to significantly more than 90 vol% hydrogen in the permeate.
Due to their excellent stability even at high temperatures, the carbon membranes are also suitable for the separation of CO² from industrial gases. During test runs at relevant CO² emitters (steel, lime and dolomite works, biogas plants), CO² concentrations of more than 97 % could be achieved. This makes it possible to further utilize the separated CO² as a raw material for non-fossil fuels or chemicals, for example.
Centralized looping of waste water to drinking water
Central waste water treatment plants are usually based on biological processes, which limits their performance and availability. Certain substances, such as drug residues, are not degraded. Moreover, the systems cannot be switched on and off at will and are therefore not very flexible. Fraunhofer IKTS water treatment systems offer an alternative here, as purely physical-chemical processes such as filtration, electrolysis and photocatalysis are coupled together. It is crucial to design reactors and process chains in such a way that these processes are combined in a very confined space with high energy efficiency in order to treat waste water into drinking water. This is made possible using functionalized and highly stable ceramic components, such as membrane filters and cellular molded bodies.
Fraunhofer Institute for Ceramic Technologies and Systems IKTS