Sustainable Biological Ammonia Production towards a Carbon-Free Society

Abstract

A sustainable society was proposed more than 50 years ago. However, it is yet to be realised. For example, the production of ammonia, an important chemical widely used in the agriculture, steel, chemical, textile, and pharmaceutical industries, still depends on fossil fuels. Recently, biological approaches to achieve sustainable ammonia production have been gaining attention. Moreover, unlike chemical methods, biological approaches have a lesser environmental impact because ammonia can be produced under mild conditions of normal temperature and pressure. Therefore, in previous studies, nitrogen fixation by nitrogenase, including enzymatic ammonia production using food waste, has been attempted. Additionally, the production of crops using nitrogen-fixing bacteria has been implemented in the industry as one of the most promising approaches to achieving a sustainable ammonia economy. Thus, in this review, we described previous studies on biological ammonia production and showed the prospects for realising a sustainable society.

Engineering of Bimetallic Cu–Pt Nanostructures for the Electrochemical Ammonia Synthesis via Nitrate Reduction

“…14−17 Other NH 3 synthesis approaches such as geochemical and biological pathways are not much favored owing to their poor production rate. 18 Therefore, exploring novel solutions, which enable environmentally friendly and energy-efficient production of green NH 3 , are urgently required. 19 Since the 1960s, the electrochemical N 2 reduction reaction (N 2 RR) to NH 3 has attracted widespread research interests.…”

“…It is used to manufacture industrial chemicals, fertilizers, and fuel. − Additionally, NH 3 has the potential to be a carbon-free energy carrier due to its high hydrogen capacity, high energy density, and low liquefaction point. − Currently, the industrial production of NH 3 predominantly occurs through the Haber–Bosch (H–B) process − which involves using hydrogen (H 2 ) and nitrogen (N 2 ) as feed gases under extreme conditions (350–550 °C, 150–350 atm). However, this process results in significant carbon emissions and high energy consumption. − Other NH 3 synthesis approaches such as geochemical and biological pathways are not much favored owing to their poor production rate . Therefore, exploring novel solutions, which enable environmentally friendly and energy-efficient production of green NH 3 , are urgently required .…”

Boron Insertion into the N≡N Bond of a Tungsten Dinitrogen Complex

“…Due to the high pressures (150–300 bar) and temperatures (400–500 °C) required, it accounts for 1.4% of global CO 2 emissions and 1–2% of the world’s total energy consumption. Furthermore, the production of the H 2 required for this process is heavily reliant on fossil fuels. , In recent years, considerable efforts have been undertaken to make ammonia production from N 2 more sustainable, including the design of new hetero- and homogeneous catalysts, integrated electro- and photocatalytic processes, and even biological ammonia production. − …”