With the proposal of a "carbon reduction" global goal, hydrogen is considered the ideal clean energy, but problems such as high production cost, storage, and transportation difficulties limit the large-scale energy application of hydrogen. Used as the carrier of hydrogen. green ammonia, with the meaning of zero carbon footprint, has attracted more and more attention. This study provides an overview of the potential energy applications for green ammonia, the development of green ammonia, and the application progress of ammonia fuel. Furthermore, this study introduces the source of green ammonia. The prospect and challenges of large-scale application of green ammonia are analyzed according to the production cost, technology maturity, and policy factors of green ammonia. Presently, ship transportation and power generation are essential target application fields of ammonia fuel. However, there are still some problems, including the safety of ammonia, mixed combustion theory, and combustion system transformation, among others. An ammonia fuel cell is an essential technology for the energy conversion of ammonia. The research progress of ammonia fuel cell is introduced in detail, including oxygen ion-conducting electrolyte ammonia solid oxide fuel cell, proton-conducting electrolyte ammonia solid oxide fuel cell, proton membrane-ammonia fuel cell and alkaline ammonia fuel cell. The comprehensive analysis shows that the global carbon reduction policy is essential for developing green ammonia at this stage. In the short term, proton membrane-ammonia fuel cell and alkaline ammonia fuel cell would not be able to handle the large-scale application of ammonia fuel. Solid oxide fuel cell with high fuel flexibility is the most promising type of ammonia fuel cell.
Table 1 Energy requirement and CO2 footprint of brown ammonia, blue ammonia, and green ammonia based on the conventional high-pressure ammonia synthesis loop
Fig. 3
Summary of existing problems of ammonia cofiring in utility boilers
由于氨具有毒性和强烈的刺激性气味等特性,加之现有燃料加注体系已经非常成熟,大范围加装氨燃料加注系统难度大等原因,极大地增加了氨燃料在常规汽车上的应用难度。氨在船舶运输、电站锅炉、工业锅炉等领域具有良好的应用前景,但是,还需要解决氨燃料的泄漏、毒性、腐蚀性、燃烧产生NO x 、掺烧比例低以及燃烧系统改造升级等难题。
Fig. 7
The current-voltage (I-V) and current-power (I-P) relationships of HMFC operating by feeds of a) H2 (pH2=1.0) and b) NH3 at various temperatures
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... [2]Summary of existing problems of ammonia cofiring in utility boilersFig. 3
由于氨具有毒性和强烈的刺激性气味等特性,加之现有燃料加注体系已经非常成熟,大范围加装氨燃料加注系统难度大等原因,极大地增加了氨燃料在常规汽车上的应用难度.氨在船舶运输、电站锅炉、工业锅炉等领域具有良好的应用前景,但是,还需要解决氨燃料的泄漏、毒性、腐蚀性、燃烧产生NO x 、掺烧比例低以及燃烧系统改造升级等难题. ...
... [2]Summary of existing problems of ammonia cofiring in utility boilersFig. 3
由于氨具有毒性和强烈的刺激性气味等特性,加之现有燃料加注体系已经非常成熟,大范围加装氨燃料加注系统难度大等原因,极大地增加了氨燃料在常规汽车上的应用难度.氨在船舶运输、电站锅炉、工业锅炉等领域具有良好的应用前景,但是,还需要解决氨燃料的泄漏、毒性、腐蚀性、燃烧产生NO x 、掺烧比例低以及燃烧系统改造升级等难题. ...
... [37]The current-voltage (I-V) and current-power (I-P) relationships of HMFC operating by feeds of a) H2 (pH2=1.0) and b) NH3 at various temperaturesFig. 74.3 质子膜氨燃料电池