New Strategy of Fuel-Slurry Integrated Gasifier/Gas Turbine (FSIG/GT) Alternative for Power Generation Applied to Biomass

Abstract

The new strategy of the fuel-slurry integrated gasifier/gas turbine (FSIG/GT) concept for thermoelectric power generation is applied to the case of sugar cane bagasse (SCB). The FSIG/GT process allows fuel feeding to a power unit based on gasification using commercially available slurry pumps, thus avoiding the usual sequential lock-hoppers, also known as 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. The fuel slurry is prepared to high dry-solid content and pumped into a dryer, from which the solid particles are fed into the gasifier. Because both units 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. The work shows that no steam is needed as gasification agent, thus simplifying the process and decreasing the capital costs. Moreover, the strategy leads to higher efficiency when compared with power generation based on high-pressure steam turbines, BIG/GT process consuming SCB, and combined cycles using pressurized-chamber boilers.