Introductory study on Fuel-Slurry Integrated Gasifier/Gas Turbine (FSIG/GT) alternative for power generation applied to high-ash or low-grade coal

This is the first round of studies to verify the technical feasibility of applying the Fuel-Slurry Integrated Gasifier/Gas Turbine (FSIG/GT) concept for thermoelectric power generation consuming high-ash coal (HAC). Such resource is, in most instances, considered unprofitable and usually discarded as a residue. This is part of a series dedicated to the application of FSIG/GT, which has already shown the possibility of increasing the efficiencies of conventional power generation based on sugar-cane bagasse and municipal solid waste (MSW). As before, a water-slurry of fuel particles is injected into pressurized vessels using commercially available pumps. Therefore, it avoids the cumbersome sequential or cascade feeding systems. In addition, the process does not need the application of pure oxygen or hydrocarbons to ignite the particles in the injected slurry. The slurry is prepared to contain fractions of dry-solid fuel near the limit allowed for the operation of slurry pumps. The slurry is injected into a dryer, from which the dry solid particles enter the gasifier. As the dryer and gasifier operate under similar pressures, simple rotary valves and Archimedes' screws can accomplish the transference from one vessel to the other. The produced fuel gas is cleaned to decrease its particle content and size as well alkaline concentration and reach acceptable limits for injections into standard gas turbines. Power steam turbine cycles are used to recover energy. Having in mind the low quality of HAC as fuel, the overall power generation efficiencies attained in the present study seem reasonable. Nonetheless, unlike conventional processes consuming HAC, the present one does not require de-ashing. Future studies will explore possibilities of improving the values achieved at the present instance. (C) 2014 Elsevier Ltd. All rights reserved.