Objective The article focuses on researching the technical and economic feasibility of retrofitting coal-fired power plants with ammonia for low-carbon conversion.

Method This study adopted a research method combining literature review, comparative analysis, and quantitative modeling to analyze and evaluate the current development status of fuel ammonia technology in major foreign countries such as Japan, South Korea, and Australia, as well as the current situation in China. It summarized the development demands from aspects such as carbon emission constraints, resource bases, and energy security. Meanwhile, by constructing an economic assessment model for ammonia co-firing in coal-fired power plants, it quantitatively analyzed the mechanism and degree of influence of key factors—such as ammonia price, carbon price, coal price, and benchmark electricity price—on the technical and economic feasibility of coal-ammonia co-firing.

Result The results indicate that when the coal price is 400 CNY/t and the ammonia price is 2000~6000 CNY/t, the co-firing ratio reaches 5.7%~18.6%. When the coal price rises to 700 CNY/t, the co-firing ratio drops to 2.4%~8.6% under the same ammonia price. When the CCUS cost is 200 CNY/t and the carbon price is 100~300 CNY/t, the carbon reduction ratio can reach 16.1%~65.4%. When the emission reduction ratio is 5%~10%, ammonia co-firing in coal-fired power plants is more economically advantageous. When the emission reduction ratio is over 20%, the ammonia price needs to be lower than 1800 CNY/t. When the CCUS retrofit cost is 200 CNY/t and the carbon price is 112 CNY/t, or 300 CNY/t and the carbon price is 240 CNY/t, and when the coal price is 700 CNY/t and the benchmark electricity price increases by 40%, the maximum acceptable increase in ammonia price is 161.5%.

Conclusion Coal-ammonia co-firing technology can ensure the reduction of carbon emissions in thermal power while meeting the technical requirements for stable combustion in power generation. In the early stage of the low-carbon transition of coal-fired power plants, the marginal generation cost is not sensitive to the ammonia price, and it exhibits a greater marginal economic benefit advantage compared to CCUS retrofits. Compared with the coal price, the acceptable ammonia price is more sensitive to the increase in the benchmark electricity price level. Coal-ammonia co-firing technology is expected to provide strong support for the carbon peaking of coal-fired power plants.