Abstract:
Molten carbonate fuel cell (MCFC) is an interesting device that can directly convert chemical energy in fuels into electrical energy with high efficiency of electricity production and low emissions. However, MCFC still emits CO2 eventually since it usually uses fossil fuels as hydrogen source. This study proposed the combination of MCFC system and CO2 capture by chemical looping air separation. The integrated system was designed and simulated by using Aspen Plus. The model uses diesel as a fuel and Mn as oxygen carrier. The model is divided into 2 cases, including the case using CO2 as a gas carrier and the other using steam as a gas carrier. Results show that electrical efficiency of the proposed model are lower than MCFC without CO2 capture but it has 81.13% CO2 capture ratio. Furthermore, the model with CO2 as a gas carrier gives more electrical efficiency than that steam as a gas carrier, 50.78% and 50.03% respectively. In addition, the former case provides lower CO2 emission and specific energy consumption of CO2 capturing (SECCO2) than that using steam, 2.72 and 2.76 molCO2/kWh and 109.27 and 120.84 kJ/molCO2, respectively. Operating parameters that affect electrical efficiency and CO2 capture capability were also examined. The optimum condition was found to be steam to carbon ratio of 3, reforming temperature of 800 °C, MCFC operating temperature of 750 °C, fuel utilization of 79% and CO2 utilization of 65%. The electrical efficiency of 53.04% and SECCO2 of 122.12 kJ/molCO2 are obtained.