Energy & Fuels, Vol.27, No.12, 7696-7713, 2013
Fuel-Slurry Integrated Gasifier/Gas Turbine (FSIG/GT) Alternative for Power Generation Applied to Municipal Solid Waste (MSW)
The Fuel-Slurry Integrated Gasifier/Gas Turbine (FSIG/GT) concept for thermoelectric power generation is applied to the case of Municipal Solid Waste (MSW). This alternative allows fuel feeding to a power unit based on gasification using commercially available slurry pumps without the need of usual sequential or cascade feeding systems. It also dispenses with the need of pure oxygen-sometimes combined with hydrocarbons-to promote ignition of particles in the injected slurry. In the presently proposed process, the fuel slurry is prepared to high content of dry-solid and pumped into a dryer, from which the solid particles are fed into the gasifier. Since both equipment operate under similar pressures, simple rotary valves and Archimedes' screws might carry the secondary feeding. The gas is cleaned to bring the particle content and size as well alkaline concentration within the acceptable limits for injections into standard gas turbines. Heat-recovering systems are applied to power steam turbine cycles, consequently increasing the overall power-generation efficiency. The present study shows the theoretical feasibility of applying FSIG/GT process to the case of MSW leading to overall efficiencies at similar or even higher values than the achieved by conventional processes based on steam turbines. Additionally, it applies relatively simple bubbling fluidized bed dryers and gasifiers, thus avoiding the use of complex and costly boilers.