Research on the Approach and Challenges of Green Ammonia as Hydrogen Carrier

Abstract The difficulties in hydrogen storage and transportation have become the main bottleneck that restricts the large-scale development of the hydrogen energy industry. As a solution for hydrogen storage, ammonia has a high hydrogen storage density, provides mild storage conditions, possesses mature and complete conditions for production, storage and transportation, providing a means to address the problem of hydrogen storage and transportation. However, the question such as whether the process is economical is still lack of enough research. This study is aimed to summarize the current development of synthetic ammonia industry and discuss the development path of ammonia in hydrogen energy industry. Based on the upon analysis, we propose thoughts on the development of the world synthetic ammonia industry, and points out four development paths. We analyzes economy of synthetic ammonia made from electrolytic hydrogen as an alternative to coal, cost of ammonia as a carrier for transportation of hydrogen. When the electricity price is RMB 0.2/kWh, the cost of green ammonia production is RMB 2,095/t, which is comparable to the cost of gray ammonia production when the coal price is RMB 900/t; when the electricity price is RMB 0.1/kWh, the cost of green ammonia production is RMB 1,115/t, which is comparable to the cost of gray ammonia production when the coal price is RMB 277/t. Four feasible development paths of China's ammonia industry are proposed. Firstly, integrating green hydrogen into ammonia synthesis plants to expand green ammonia production capacity and reduce carbon emissions. Secondly, consuming renewable energy electricity to produce ammonia. Thirdly, efficiently integrating byproduct hydrogen resources into ammonia production to enhance economic benefits. Last but not least, using offshore wind power to develop distributed and miniaturized ammonia synthesis projects.