Simultaneous production of H_2 and C_2 hydrocarbons by using a novel configuration solid-electrolyte + fixed bed reactor

摘要

A novel combined single chamber solid electrolyte plus fixed bed reactor configuration was developed for the simultaneous production of H_2 and C_2 hydrocarbons from a humidified CH_4 atmosphere. Hence, a Pt/YSZ/Ag solid electrolyte cell was placed on the top of an active oxidative coupling catalyst powder bed Ce-Na_2WO_4/SiO_2. H_2 was produced via steam electrolysis in a Pt cathode of the solid electrolyte cell (H_2O + 2e → H_2 + O~2 ). Simultaneously, the produced O~2 ions were electrochemically pumped to the Ag anode, leading to the C_2s production, via oxidative coupling of CH_4 (4CH_4 + 3O~2 →C_2H_4 + C_2H_6 + 3H_2O + 6e ). Additionally, non-reacted O~2 molecules desorbed to the gas phase (2O~2→ O_2+4e ) and reacted with CH_4 in the catalyst bed leading to an increase of C_(2S) yield. The influence of different reaction parameters was investigated together with long-term reaction experiments, confirming the stability of this configuration for its practical application. The obtained results demonstrated that the addition of an active catalyst bed strongly enhances both: the efficiency of the single chamber steam electrolysis and the oxidative coupling process.