Thermodynamic analysis of ammonia co-firing for low-rank coal-fired power plant

ABSTRACT

As one of the largest sources of CO₂ emissions, the integration of non-carbon fuels in coal-fired power plants will significantly impact the global decarbonisation strategy. Hydrogen is a potential non-carbon fuel, and ammonia is a promising hydrogen carrier fuel. In this study, the effect of ammonia co-firing in a low-rank coal-fired power plant is thermodynamically modelled and evaluated in Aspen Plus V12.1. The integrated co-firing system is modelled in two different cases. The first case is made to maintain the combustion process, resulting in constant excess oxygen content in the flue gas. The second case is to minimise the fan modification in the power plant by maintaining the maximum air flow rate. The results show that increasing fraction of ammonia reduced CO₂ and SO_x emissions due to the decreasing coal fraction. NO_x emission proportionally changes with the furnace temperature, which increases at constant excess oxygen case and decreases at constant airflow case. It was also shown that both cases’ boiler efficiency is relatively similar on the same ammonia fraction. The thermodynamic analysis provides an initial assessment of the implementation of ammonia co-firing in coal-fired power plants as an effort of decarbonisation in the energy sector.

KEYWORDS:

• Ammonia co-firing
• coal-fired power plant
• CO₂ emission
• thermodynamics

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Research and Community Service Program ITB (PPMI) [2022].