Abstract: In a system of fluidized gasification of carbonaceous solids in which fines are burned in an external combustor to heat recycle solids, fines entrainment is reduced by introducing the finest of the fines into the combustor from the lower end of a fluidized fines feeder vessel whereby the said finest fines are selectively burned.

Abstract: In the multi-stage fluidized carbonization of coal to produce, oil, gas and char, oil containing vapors from the first stage are used as the fluidizing gas to dry the incoming coal feed. The oil vapor pressure of the fluidizing gas is maintained at a value under 10 mm. to prevent oil condensation in the fluidized drying vessel. The technique makes possible the recovery of sensible heat from the first stage overheads.

Abstract: Hydrocarbonaceous material produced from pyrolysis of coal and shale is subjected to hydrogenation and fines removal by first passing it through an ebullating bed reactor in which the hydrocarbonaceous material is partially hydrogenated and partially vaporized. The vapor is then separated and further hydrogenated while the fines in the liquid portion are concentrated and removed as a slurry. The remaining liquid is vaporized, either by recycling it through the ebullating bed reactor or by flash evaporation, to rid it completely of fines. The thus vaporized remaining liquid is also subjected to further hydrogenation.

Abstract: A method and apparatus for mixing coal char particles with a hot stream of combustion gases containing molten ash particles, in order to prevent build-up of ash in the apparatus. The coal char particles, fluidized with a gas, are discharged as an annulus about the stream of combustion gases, so that the molten ash particles are cooled and solidified by progressive mixing with the char particles and thus prevented from reaching the walls of the apparatus in a molten state.

Abstract: In the process of making synthesis gas in a fluidized bed from carbon and steam, wherein a recirculating stream of carbon from the bed is heated externally of the bed with combustion gases derived by burning carbonaceous solids taken from the bed, using all the fines separated from the synthesis gas withdrawn above the fluidized bed, and such additional carbon from the bed as is necessary to make up the required heat balance, the ash content of the bed is maintained near feed levels by drawing char from the bed, fractionating it to obtain an ash-rich fraction and an ash-poor fraction, returning the ash-poor fraction to the gasifier and sending the ash-rich fraction to the combustor.

Abstract: Synthesis gas is prepared by contacting coal-derived char particles with steam in a fluid-bed gasifier wherein heat for the endothermic reaction is supplied by passing through the gasifier a stream of inert pellets heated externally of the gasifier. The pellets, after leaving the gasifier, are separated from entrained char, and then conveyed into a heater where the fines from the external cyclone of the gasifier are burned in the presence of the circulating pellets to produce the heat necessary for the reaction.

Abstract: Waste water formed in the gasification of coal and containing ammonia, H.sub.2 S, and phenolic compounds is treated to remove H.sub.2 S and a substantial proportion of its ammonia, while leaving sufficient ammonia in the water to maintain a pH of at least 8 (such as up to about 10.5, preferably about 8.5 to 9), the ammoniacal water is then flashed into a stream of superheated steam being fed to gasification zone. At the high temperatures in the gasification zone the organic impurities are decomposed.

Abstract: Coal gasification process gives a waste water stream containing phenolic impurities. This stream is fed into contact with hot solid heat transfer particles to form superheated steam which is fed to the gasification zone.