Cerca nel sito per parola chiave

pubblicazioni - Poster

Microstructural investigation of La0.6Sr0.4Co0.2Fe0.8O3-d after long-term operation in the presence of CO2-rich atmosphere

pubblicazioni - Poster

Microstructural investigation of La0.6Sr0.4Co0.2Fe0.8O3-d after long-term operation in the presence of CO2-rich atmosphere

In questo lavoro è stata studiata la stabilità di membrane LSCF nel corso di test a lungo termine ad alta temperatura e in presenza di CO2, seguiti da analisi microstrutturali. I risultati dei test di permeazione hanno messo in luce buone prestazioni e stabilità delle membrane LSCF.

In this work the stability of LSCF membranes was studied by performing long term tests at high T and in the presence of CO2, followed by microstructural investigation analyses.High temperature (850°C) permeation tests have been performed on asymmetric La0.6Sr0.4Co0.2Fe0.8O3-δ membranes, manufactured by FZJ, by feeding air on the membrane side and pure He or a 80%CO2/20%He mixture as sweep gas on the support side of the sample. The stability of the samples has been checked by continuously measuring the O2 content in the permeate side for 1000 hours. Results show that O2 flux decreases rapidly when the CO2 is fed in the sweep gas stream, and a relative O2 flux reduction of the 33% has been estimated.

Moreover, the O2 flux slightly decreases during the long term tests in CO2 and an additional O2 flux reduction of the 15% after about 1000 hours has been estimated. When the sweep gas has been switched back to pure He the O2 flux increases but it is not completely restored, probably due to the membrane degradation during the high temperature exposure. The membrane microstructure has been characterized by SEM. Co-oxide particles have been identified on the whole membrane surface while on the permeate side a Sr enrichment has been detected.

This result confirmed that the O2 flux reduction is mainly due to kinetic demixing, which doesn”t affect significantly the membrane performances. Long term permeation tests in the presence of CO2 revealed good performance and stability of LSCF membranes.

Progetti

Commenti