Techno-economic analysis of ammonia storage and supply system for co-firing at coal-fired power plant

Abstract Although coal-fired power plants continue to dominate Indonesia’s electricity generation, the country aims to achieve carbon neutrality by 2060. According to the 2024–2060 National Energy General Plan, ammonia is expected to contribute 3.1% to electricity production. Global research on ammonia co-firing has yielded positive results, demonstrating that higher co-firing ratios lead to greater carbon emission reductions. Studies also indicate that a co-firing ratio of 20%–25% has minimal impact on furnace temperature. Additionally, efficiency assessments of 20% ammonia co-firing with bituminous and sub-bituminous coal types have shown promising outcomes. Existing research primarily focuses on in-boiler combustion effects, emissions, and plant performance. This study proposes a supporting system for ammonia co-firing at a 20% ratio, encompassing storage and supply infrastructure. The mass basis approach is adopted due to the comparable lower heating values of ammonia (18.6 MJ/kg) and low-range coal (16.3 MJ/kg). The system is designed to support ammonia co-firing at the Suralaya Coal-Fired Power Plant units 5, 6, and 7 over a 10-day operational period, requiring a total of 47 520 tons of ammonia. System modeling using Aspen HYSYS software was conducted to determine the specifications of key equipment. The economic analysis estimates that implementing an ammonia storage and supply system at the Suralaya Coal-Fired Power Plant would increase annual expenditures by USD 4 293 363.12.