Research Project GREEN-CC

Major sources for human made CO₂ emissions comprise the energy and the industrial sector including cement production. One of the most appropriate concepts to capture CO₂ from such point sources is the oxyfuel combustion.

The main energy demand for this method results from the O₂ generation, which is usually done by air liquefaction. This energy demand can substantially be lowered using thermally integrated separation modules based on ceramic oxygen transport membranes (OTM). It is least if the OTM is integrated in a 4-end mode, which entails that the permeating oxygen is swept and directly diluted using recirculated flue gas.

Up to 60% reduction in capture energy demand compared to cryogenic air separation and up to 40% reduction compared to post-combustion capture approaches can be achieved.
GREEN-CC will provide a new generation high-efficiency capture process based on oxyfuel combustion. The focus lies on the development of clear integration approaches for OTM-modules in power plants and cement industry considering minimum energy penalty related to common CO₂ capture and integration in existing plants with minimum capital investment. This will be attained by using advanced process simulations and cost calculations. GREEN-CC will also explore the use of OTM-based oxyfuel combustion in different highly energy-demanding industrial processes, e.g. oil refining and petrochemical industry.
However, highly permeable membrane materials show a chemical instability against CO₂ and other flue gas components. One major challenge faced by GREEN-CC is therefore to identify and develop membrane materials, components, and a PoC-module for the 4-end mode OTM integration. The desired membrane assembly will consist of a thin membrane layer supported on substrates with engineered porosity and oxygen reduction catalysts with high and stable activity in flue gas. As proof of concept, a planar membrane module will be developed which involves technical hurdles like joining technology.