Techno-economic analysis on oxy-fuel based steam turbine power system using municipal solid waste and coals with ultrasonicator sulfur removal

Abstract

Municipal solid waste (MSW) is a carbon–neutral energy source and possesses a moderate heating value; hence, it can be used as an alternative fuel for coal. To use high ash and high sulfur Indian coals efficiently, a techno economic analysis is performed for electricity generation using supercritical and subcritical based steam turbines operating in the oxy-fuel co-combustion mode of MSW with Indian coals. The impact of the capture of direct and indirect greenhouse gasses such as CO₂, NO_x and SO_x on the net thermal efficiency of the power plants is assessed. The supercritical based steam turbine achieved a higher net thermal efficiency by 8.8% using MSW based feedstock compared to sub-critical conditions. The co-combustion mode reduced the levelized cost of electricity (LCOE) by 48–73 $/MWh. Techno-economic analysis for sulfur removal in coal using ultrasonication technology has not yet been reported in the literature. The incorporation of an ultrasonicator (a pre-combustion sulfur remover) and a duct sorbent injector (a post-combustion SO_x absorber) increased the LCOE by 1.39–2.75 $/MWh. In high sulfur coals, the SO_x emissions decreased from 224.79 mg/m³ to 9.2 mg/m³.