Extended MTU-test campaign at Klemetsrudanlegget

The purpose of the project was to demonstrate that Aker Solutions’ amine technology is suitable for capturing CO₂ from flue gas stemming from a Waste-to-Energy plant.

The main goals have been to test on actual flue gas in order to demonstrate stable operation at conditions similar to those expected for a full scale facility, and to verify critical process parameters such as energy requirement, solvent degradation and emissions.

The MTU was in operation on KEA line 3 flue gas until end of 2016, and achieved a total of 3 530 hours of operation

Resulting CO₂ mass balances show an excellent agreement with an accuracy of +/- 2-3%

Specific Reboiler Duty (SRD) values was obtained for various operating conditions and used for optimisation of operation parameters. SRD values are considered sensitive information and are not given here.

Measured amine loss was very low and shows that solvent degradation rate as well as amine emission to air is low.

The test campaign showed low resulting content of metals such as Fe, Ni and Cr in the solvent, indicating that the solvent is not corrosive for the applied construction materials. Accumulation of chloride, sodium and potassium in the solvent was observed, indicating that sodium chloride and potassium chloride are washed out from the flue gas as fine particulates. Chlorides in the solvent must be carefully monitored and controlled, as chlorides can cause stress corrosion in stainless steel under certain conditions.

Organic acids are typical amine degradation products, but were detected in trace amounts only, and in line with the low observed degradation level. Measured level of heat stable salts (HSS) again indicates proper operation of the DCC as well as low solvent degradation rate.
Visual examination of solvent samples collected at start-up and at the end of the period did not indicate sign of any significant degradation. The solvent remained clear and visibly unchanged throughout the test campaign. No increase in solvent viscosity was measured.
No amine mist emission was measured by the online FTIR.

The results were obtained with Aker Solutions’ ACCTM anti mist system which is part of the MTU’s emission control system.

Manual flue gas emission measurements validated the low emission of solvent amines. This indicates that Aker Solutions’ emission control system performs very well. Ammonia, alkyl amines and aldehydes were emitted in the same rates as they were formed in the process, and the emitted amounts were found to be very low and as expected for the S26 solvent with low degree of degradation.

No nitrosamines nor nitramines were detected in the flue gas with state-of-the-art detection limits.

All in all, the obtained results from the EGE Klemetsrud MTU S26 campaign confirm that amine based CO₂ capture from the WtE plant line 3 at Klemetsrud is technically feasible using Aker Solutions ACCTM technology. The results furthermore confirm that Aker Solutions’ ACCTM solvent S26 is energetically attractive, and has excellent degradation and HSE characteristics with very low emissions to air.