Long-term activity of a CuO/SBA-15 type SOx adsorbent: Impact of the regeneration step

Influence of the water vapor on the activity of CuO/SBA-15 SOx adsorbents

“…These curves indicate that after around 2 000 s, SO2 begins to be detected in the output gas stream and its concentration increases and reaches a plateau at 185 ppm, while 250 ppm is still injected. As previously explained [10][11][12][13]20], this difference between the injected and the emitted values of SO2 indicates that the copper based active phase is still able to oxidize SO2 to SO3 (this latter not being detected by the analyzer) at the end of the adsorption step, despite its progressive saturation due to the formation of copper sulphates. Excepted for cycle 1 where the SO2 breakthrough occurs at about 3 000 s, the DeSOx performance of the adsorbent is relatively similar along cycles, in terms of SO2 breakthrough curve profile (Figure 3a) and SO2 adsorption capacity of the adsorbent at the breakthrough (Figure 4b), as already observed in these operating conditions [11][12][13].…”

“…The deposition of the CuO active phase on the SBA-15 support was achieved by wet impregnation in water [10][11][12][13]20]. Before to deposit the copper active phase, different samples were prepared to study the impact of each step of the impregnation process on the textural properties of the SBA-15 support:…”

“…The fully automated system (Figure 1) used to evaluate the cyclic SO2 adsorption and regeneration abilities (DeSOx performance) of the CuO/SBA-15 absorbents, has been amply described and validated in our previous work [10][11][12][13]. However, a study under wet conditions implied some adjustments:…”

“…These latter materials have the ability to be regenerable and provide an FGD process without liquid or solid effluents production. In particular, copper oxide supported on an organized mesoporous SBA-15 silica, called CuO/SBA-15, has demonstrated a high SO2 adsorption capacity under SO2/N2 atmosphere [10][11][12][13] along several adsorption/regeneration cycles without water. The set of chemical reactions involved in this regenerative FGD is:…”

“…a process which operates in the same thermal conditions than the ones of the exhaust flue gas (300 -500 °C) during cyclic adsorption/regeneration [11][12][13]20].…”