B-site cobalt-doped perovskite oxide BaNiO3 oxygen sorbents for performance improvement of oxygen enriched gas production

Abstract

B-site cobalt-doped perovskite oxide BaNiO₃ oxygen sorbents have been synthesized by an EDTA sol–gel method and further applied for producing oxygen. BaCo_xNi_1−xO_3−δ oxygen sorbents were characterized by scanning electron microscopy (SEM) and cyclic oxygen adsorption/desorption experiments. Results showed that BaCo_0.6Ni_0.4O_3−δ features higher production amounts of oxygen among the candidates. The operating factors of oxygen releasing performance were investigated in detail including adsorption temperature, desorption temperature, adsorption time, CO₂ flow rate and CO₂ partial pressure. It was concluded that the temperature and CO₂ flow rate are the main reasons affecting the performance of perovskite oxygen sorbents. The optimal operating parameters of oxygen releasing performance for BaCo_0.6Ni_0.4O_3−δ were as follows: adsorption temperature was 850 °C, desorption temperature was 850 °C, air adsorption time was 30 min, CO₂ flow was 200 ml min⁻¹ and the ratio of CO₂/N₂ was 100 : 0. The oxygen production amount of BaCo_0.6Ni_0.4O_3−δ was 49.5 mg g⁻¹ under the optimal reaction conditions. Finally, multiple cycles demonstrated that BaCo_0.6Ni_0.4O_3−δ displays higher stability and regeneration capacity, which is the key factor providing a stable O₂/CO₂ gas stream for oxyfuel combustion application.