Abstract: A hybrid biomass natural gas/oil power generator system includes a circulating fluidized bed boiler which burns, for example, wood chips, a combustion turbine driven mainly by natural gas and a steam turbine. The wood chip boiler has its hot flue gas utilized to provide both steam, hot water and hot air which is eventually used by the combustion turbine. This hot air is first humidified and then has its temperature raised to approximately the boiler temperature by passing it over or through hot solids obtained from the boiler. The filtered humid air is mixed with steam and combusted natural gas to drive the combustion turbine. Lastly the hot solids from the boiler are also used for drying the wood fed to the wood chip boiler.

Abstract: A method is provided for improving the sulfur capture potential of lime in the fluidized bed combustion of coal and for improving the flow characteristics of the feed coal therefor comprising collecting partially sulfated limestone particles from the fly ash of the flue gas from the fluidized bed combustor, and (a) retaining said particles in the flue gas stream, thereby hydrating said particles, and returning said particles to the combustor; or (b) mixing said partially sulfated limestone particles with wet coal thereby drying said coal and simultaneously hydrating unreacted calcium oxide to form calcium hydroxide, and recycling said mixture of dry crushed coal and calcium hydroxide into said fluidized bed combustor; or (c) introducing wet coal in the flue gas upstream from said collected particles, thereby providing moisture to hydrate said particles, and returning said hydrated particles to the combustor.

Abstract: A fluid bed boiler and combustion method are provided having a first fast bed combustion zone followed by a second slow bed combustion zone. Coal, as a typical fuel, and limestone are fed to the first zone, where the coal undergoes combustion and sulfur is captured by the limestone. The solids which flow from the top of the first combustion zone are separated and introduced into a low velocity "slow" bubbling fluid bed in which arrays of heat exchange tubes are immersed. Additional heat transfer to water can be achieved by employing water walls for the first fast bed combustion zone.