One-step method to produce feedstock for green ammonia of H2:N2≥3:1 by solid oxide cell

Abstract

It is significant to develop a green ammonia preparation method for decreasing carbon emission. This work demonstrates a zero-carbon method for preparing ammonia feedstock consisting of a ratio of H2:N2 ≥ 3:1 by direct electrolysis of air and steam as fuel gas through solid oxide electrolysis cell (SOEC). Through adjusting the working current and proportion of air/steam, the ratio of H2 and N2 can be achieved to more than 4:1, and the fuel is pure enough to be used for synthesizing ammonia. The production rate of ammonia feedstock reaches 1.79 × 10−6 mol/ (cm2·s), and the energy conversion efficiency (ECE) reaches 69.30 %. A stable 100 h electrolysis operation is carried out to generate H2/N2 required for ammonia production. This work provides a new efficient method for the synthesis of green ammonia.