Table 1 Comparison of the actual industrial production of ammonia versus the direct electrocatalytic route. Reproduced with permission from ref. [66]. Copyright Elsevier, 2018

Actual industrial

Multistep and high pressure/temperature process, starting from natural gas. Steps: purification, steam reforming, air reforming, shift converter, CO₂ removal, methanation, compression/cooling, NH₃ synthesis, cooling/decompression. Efficient only in large-scale (transport, impact).

1.83 t_CO2/t_NH3

Direct electro-catalytic

One-single device (suited for distributed production). Start from N₂, H₂O and renewable energy, nearly room temperature and ambient pressure.

0.12 t_CO2eq/t_NH3 (93% reduction)