CO2 separation from industry emissions
In order to control CO2 emissions at national and international levels, the acquisition of emission certificates has become mandatory. Particularly affected by this policy are industries which are inherently unable to eliminate the production of CO2 for technological reasons, such as cement and chalk plants. In these cases, it is necessary to separate the generated CO2, ideally before converting it locally into non-fossil fuels or chemicals. The separation of CO2 from highly dusty exhaust gases requires a dedusting unit as well as an efficient gas separation unit based on membranes. The goal is to operate both cleaning processes at elevated temperatures, first to avoid expensive cooling and second to utilize hot CO2 – ideally at its reaction temperature – for subsequent process steps, which is required for all CO2 conversion reactions. At Fraunhofer IKTS, all competencies are available for the development, manufacturing and testing of thermally stable ceramic membranes – from porous ceramic carrier structures to the final separating membrane layer. During multi-day on-site test runs with real exhaust gases at steel, chalk and dolomite plants, our improved carbon membranes generated a CO2 flow with more than 70 % purity using a single-step separation setup. The application of a two-step separation led to CO2 purities above 97 %, which enables direct chemical conversion. A main commercial factor for membrane separation of CO2 is the manufacturing cost of the membranes. This is being addressed in current activities by upscaling the manufacturing process as well as increasing the membrane area for each support.
Flyer: Membrane Technology [ PDF 0,86 MB ]