Testing Innovative Carbon Capture Technologies 

One of POSEIDON project’s experimental activities is dedicated to developing and testing novel technologies for carbon capture. CERTH conducted tests in its laboratory in Thessaloniki, Greece, using a dedicated Membrane-Gas-Absorption (MGA) unit (see photo). This unit allows the evaluation of different CO2 capture solvents in membrane contactors, such as methanol-based solvents with different methanol concentrations. The flue gases tested by CERTH are representative of the two project case studies: the biogas plant in Valencia and the lime plant in Thessaloniki. 

The first experiments were carried out using commercial porous polymeric membrane contactors by 3M. However, the first tests were not conclusive since the conventional porous polypropylene membrane contactors suffered from strong wetting phenomena when exposed to liquid methanol, reducing their separation performance and causing operational problems. For this reason, a dedicated Ultra Phobic module employing porous polyolefin membranes with a dense outer layer, which can prevent membrane wetting, was used to evaluate the CO₂ separation performance with water/methanol mixtures. To assess the performance of the CO₂ capture technologies and have a benchmark, further tests with aqueous solutions of DEA as solvent were also conducted.  

The experimental results confirmed the high efficiency and flexibility of the studied technology. Specifically, the results showed that:

1. Increasing the liquid flow rate of the solvent enhances CO₂ absorption and mass transfer coefficients.
2. The CO₂ capture efficiency decreases for higher gas flow rates in the absorption unit, as expected.

CERTH plans to publish the results of these tests in a scientific journal. These findings contribute to better understand the performance of innovative CO₂ capture technologies and learnings will be directly used for POSEIDON’s modelling and assessment activities.