Comparative techno-economic analysis of novel bioenergy with carbon capture and storage plant versus combined cycle gas turbine with solvent-based CO2 absorption

A techno-economic analysis is performed on a negative emission power plant and a gas power plant with carbon capture. The two power plants are modelled in commercial software. The gas power plant with amine capture has been used as a reference to represent state-of-the-art power generation technology. The overall thermal efficiency for the negative emission power plant (sewage sludge as fuel) and the gas power plant (natural gas as fuel) with CO2 capture is estimated to be 35% and 54.3%, respectively. A dedicated experiment was conducted on a novel type of modular plasma gasifier with dual plasma sources in order to determine the mass and energy balance for further thermodynamic analysis. Both capital expenditures and operating expenses, as well as incomes from sewage sludge disposal and avoided CO2 emissions, have been included in the techno-economic analyses. The results show that the levelized cost of electricity of the negative emission power plant using an exhaust gas gasifier is comparable to the reference gas power plant with amine capture (107 vs. 91-95 €/MWh), while the annual avoided CO2 emission of the negative emission power plant is considerably higher (1.67 vs. 0.41 Mt). A simple payback period of 8.5 years is estimated for a power generation of 142 MW when the exhaust gas gasifier is used. Due to the high electrical energy consumption and equipment cost, the levelized cost of electricity is much higher when the plasma gasifier is used. The value strongly depends on the income from sewage sludge disposal and avoided CO2 emissions. Further reductions of levelized cost of electricity are expected for the negative emission power plant with the development of the technology maturity.