Chemical looping ammonia synthesis at atmospheric pressure benefiting from synergistic effect of Mn- and Fe-based nitrogen carriers. (22nd January 2023)

• Record Type: Journal Article
• Authors: Wang, Baoyi; Yin, Xianglei; Wang, Peng; Shen, Laihong
• Is Part Of: International journal of hydrogen energy. Volume 48:Number 7(2023)
• Page Start: 2705
• Page End: 2717
• Publication Date: 2023-01-22
• Subjects: Chemical looping ammonia synthesis (CLAS) -- N-Sorption/desorption reaction -- Nitrogen carrier; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2022.10.132
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Chemical looping ammonia synthesis (CLAS) based on the synergistic effect of Mn- and Fe-based nitrogen carriers, is proposed as an environmental-friendly NH3 production alternative. This approach has superiority of intermittent and simplified operation, especially in locations where implementing sophisticated Haber-Bosch process is challenging. This work revealed that nitrogen carriers could yield up to 166.3 μmol NH3 per gram of Mn after conversion with H2 at 600 °C. NH3 production capacity was deteriorated by sintering and ammonia decomposition at high temperature. Pores resulting from the elimination of molecular nitrogen by bursting out of the surface were found at 700 °C, which could be explained by the parasitic conversion of N to N2 rather than NH3. N-carrier with 50% Al2 O3 was the most interesting candidate with outstanding conversion ratio of lattice nitrogen. Generally, simple design, operational security and low cost make CLAS possible to scale up for industrial usage in the future. Graphical abstract: Image 1 Highlights: NH3 synthesis can be achieved under relatively mild condition (600–800 °C, 1 atm). Synergistic effect of Mn and Fe nitrides facilitates N-fixation and NH3 harvest. Separated N-sorption/desorption brings with thermodynamic and/or kinetic advantages. Easy scale-up for industrial usage due to simple design, operation safety, low cost.