Characterization and evaluation of synthetic Dawsonites as CO2 sorbents

FUEL

卷:236

Article

Lundvall, Fredrik¹  Kalantzopoulos, Georgios N.¹  Wragg, David S.¹  Arstad, Bjornar²  Blom, Richard²  Sjastad, Anja O.¹  Fjellvag, Helmer¹ 

[1] Univ Oslo, Dept Chem, Ctr Mat Sci & Nanotechnol, SMN, POB 1126, N-0318 Oslo, Norway

[2] SINTEF Ind, POB 124, N-0314 Oslo, Norway

关键词: SEWGS;    In situ X-ray diffraction;    Pre-combustion;    CO2 sorption;    Rietveld;    TGA;    DSC;    NMR;   

DOI  :  10.1016/j.fuel.2018.09.057

来源: Elsevier

【 摘 要 】

The sorbent enhanced water-gas shift (SEWGS) process has great potential for CO2 capture and is thereby a realistic alternative to conventional post-combustion capture by gas emission scrubbing. Nevertheless, better performing materials are required to make SEWGS competitive against state-of-the-art scrubbing technologies. Dawsonite, NaAl(OH)(2)CO3, has a high carbonate content and forms in situ during CO2 capture on alkali metal promoted alumina, thereby showing potential in variable temperature capture processes. For the isothermal SEWGS process the performance in pressure swing absorption is essential. We evaluate here synthetic Dawsonites [MAl(OH)(2)CO3, M=K, Na] as CO2 sorbents for the SEWGS process based on data from in situ X-ray diffraction, combined thermogravimetric analysis and mass spectrometry, magic-angle spinning nuclear magnetic resonance spectroscopy, as well as high pressure fixed bed reactor tests at isothermal conditions. The results show that synthetic Dawsonites are promising sorbents for the SEWGS process, however, with moderate cyclic CO2 capacities (similar to 0.3-0.7 mmol CO2/g sorbent) in comparison to alkali-metal promoted hydrotalcites. On the other hand, the materials exhibit relatively fast sorption rates at low temperatures (280-310 degrees C), favoring the water-gas shift reaction in the SEWGS process.

【 授权许可】

Free