Techno-economic comparison between air-fired and oxy-fuel circulating fluidized bed power plants with ultra-supercritical cycle

Abstract

Oxy-fuel combustion technology can be a solution for reducing emission of environmental pollutants because it can reduce nitrogen oxides and CO2 emissions by using oxygen rather than air as an oxidant. Incorporating the ultra-supercritical steam cycle into oxy-fuel combustion technology can result in a highly efficient and eco-friendly power generation technology, but it is essential to install additional equipment for the oxygen production and CO2 treatment. This results in an energy penalty of 8.41% and a 64% increase in capital cost compared to an air-fuel power plant, so that the air-fuel power plant's levelized cost of electricity is advantageous. However, the introduction of carbon credits trading system shows that oxy-fuel power plants are economically feasible and comparable with air-fuel power plants. The profitability and sensitivity analysis shows that the net present value and internal rate of return of oxy-fuel power plants are 2.3 times and 1.15 times larger than that of air-fuel power plant, respectively, and the payback period is reached after 12 years. According to the sensitivity analysis, fuel cost was the most sensitive factor in both types of power plants but for oxy-fuel power plants the capital cost was as sensitive as fuel cost.