THERMODYNAMIC ANALYSIS OF AMMONIA-COAL CO-FIRING PANGKALAN SUSU CFPP

• Main Author: Haykal Ahmad, Azaria
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/65312
• Institution: Institut Teknologi Bandung

Based on the net-zero emission target in 2060, efforts are needed to reduce CO2 emissions immediately. As most of the electricity in Indonesia is supplied from coal-fired power plants (CFPP), the decarbonization transition of CFPP plays a major role in reducing CO2 emissions. Ammonia has the potential to be an alternative transition from coal to non-carbon fuels, and Indonesia is one of the largest producers and exporters of ammonia. In this study, a simulation of ammonia and coal co-firing is carried out for a case study of the Pangkalan Susu CFPP with a capacity of 220 MW. Thermodynamic modeling was carried out using the Aspen Plus V12 software with two scenarios, i.e., constant excess oxygen and constant air mass rate. The mass fraction of ammonia was varied from 10% to 100% in 10% increments. Economic analysis was carried out to calculate the estimated cost of capital and gross income from ammonia co-firing. The analysis results showed that CO2 emissions decreased by 10% for every 10% increase in ammonia mass and the stack temperature increased to a maximum value of 242.48°C as the percentage of ammonia mass increased. In both scenarios, NOx emissions remain below the threshold of 550 mg/Nm3 with a maximum value in the constant oxygen excess scenario of 486.06 mg/Nm3, while in the constant air mass rate scenario, the trend shows a downward trend with a minimum value of 338.38 mg/Nm3. The boiler efficiency shows a decrease due to the increase in stack temperature and the increase in the water content in the flue gas, which can be further improved by modification in the steam line. Economic analysis was carried out on ammonia co-firing with 10% wt ammonia with an excess of oxygen scenario, showing the required capital cost of US$ 5,220,541 with a gross income of US$ 110,564,636 per year. The carbon tax policy and lowering the carbon cap can support the development of clean energy generation technologies such as the combined combustion of ammonia and coal in the energy transition process.