Abstract: A method of treating wastes includes partially combusting the wastes in a fluidized bed reactor at a relatively low temperature followed by separate gasification of gaseous material and char from the first gasification in a separate relatively high temperature reactor. This forms synthesis gas that is cooled, subjected to a conversion operation to produce hydrogen.

Abstract: In an improved system for recovering heat from a combustion gas produced by burning wastes, the combustion gas or combustible gas produced by partial burning of the wastes subjected to dust filtration in a temperature range of 450-650.degree. C. at a filtration velocity of 1-5 cm/sec under a pressure of from -5 kPa (gage) to 5 MPa before heat recovery is effected. The dust filtration is preferably performed using a filter medium which may or may not support a denitration catalyst. Heat recovery is preferably effected using a steam superheater. The dust-free gas may partly or wholly be reburnt with or without an auxiliary fuel to a sufficiently high temperature to permit heat recovery. The combustion furnace may be a gasifying furnace which, in turn, may be combined with a melting furnace.

Abstract: A method and apparatus for treating wastes by two-stage gasification recovers metals or ash content in the wastes in such a state that they can be recycled, and gases containing carbon monoxide (CO) and hydrogen gas (H.sub.2) for use as synthesis gas for ammonia (NH.sub.3) or production of hydrogen gas. The wastes are gasified in a fluidized-bed reactor at a low temperature. Then, gaseous material and char produced in the fluidized-bed reactor are introduced into a high-temperature combustor, and gasified at a high temperature and ash content is converted into molten slag. After water scrubbing and a CO conversion reaction, the gas is separated into H.sub.2 and residual gas. The residual gas is then supplied to the fluidized-bed reactor as a fluidizing gas.

Abstract: A method and apparatus for treating wastes by gasification recovers useful resources including energy, valuables such as metals, and gases for use as synthesis gas for chemical industries or fuel. The wastes are gasified in a fluidized-bed reactor at a relatively low temperature. Gaseous material and char produced in the fluidized-bed reactor are introduced into a high-temperature combustor, and low calorific gas or medium calorific gas is produced in the high-temperature combustor at a relatively high temperature. The fluidized-bed reactor preferably is a revolving flow-type fluidized-bed reactor. The high-temperature combustor preferably is a swirling-type high-temperature combustor.

Abstract: A method and apparatus for treating wastes by gasification recovers metals or ash content in the wastes in such a state that they can be recycled, and gases containing carbon monoxide (CO) and hydrogen (H.sub.2) for use as synthesis gas of ammonia (NH.sub.3). The wastes are gasified in a fluidized-bed reactor at a relatively low temperature, and gaseous material and char produced in the fluidized-bed reactor are introduced into the high-temperature combustor. The synthesis gas is produced in the high-temperature combustor at a relatively high temperature, CO and H.sub.2 O in the synthesis gas is converted into CO.sub.2 and H.sub.2, and then H.sub.2 is recovered by removing CO.sub.2.

Abstract: A combustion method and apparatus in which combustible matter, e.g., waste matter, coal, etc., is gasified to produce a combustible gas containing a sufficiently large amount of combustible component to melt ash by its own heat. A fluidized-bed furnace has an approximately circular horizontal cross-sectional configuration. A moving bed, in which a fluidized medium settles and diffuses, is formed in the central portion of the furnace, and a fluidized bed, in which the fluidized medium is actively fluidized, is formed in the peripheral portion in the furnace. The fluidized medium is turned over to the upper part of the moving bed from the upper part of the fluidized bed, thus circulating through the two beds. Combustible matter is cast into the upper part of the moving bed and gasified to form a combustible gas while circulating, together with the fluidized medium.

Abstract: A combustion apparatus in which combustible matter, e.g., waste matter, coal, etc., is gasified to produce a combustible gas containing a sufficiently large amount of combustible component to melt ash by its own heat. A fluidized-bed furnace has an approximately circular horizontal cross-sectional configuration. A moving bed, in which a fluidized medium settles and diffuses, is formed in the central portion of the furnace, and a fluidized bed, in which the fluidized medium is actively fluidized, is formed in a peripheral portion in the furnace. The fluidized medium is turned over to the upper part of the moving bed from the upper part of the fluidized bed, thus circulating through the two beds. Combustible matter is cast into the upper part of the moving bed and gasified to form a combustible gas while circulating, together with the fluidized medium.

Abstract: A combustion method and apparatus in which combustible matter, e.g., waste matter, coal, etc., is gasified to produce a combustible gas containing a sufficiently large amount of combustible component to melt ash by its own heat. A fluidized-bed furnace has an approximately circular horizontal cross-sectional configuration. A moving bed, in which a fluidized medium settles and diffuses, is formed in a central portion of the furnace, and a fluidized bed, in which the fluidized medium is actively fluidized, is formed in a peripheral portion in the furnace. The fluidized medium is turned over to the upper part of the moving bed from the upper part of the fluidized bed, thus circulating through the two beds. Combustible matter is cast into the upper part of the moving bed and gasified to form a combustible gas while circulating, together with the fluidized medium.

Abstract: A method of and apparatus for dewatering a substance which is to be dewatered such as sludge wherein the substance to be dewatered is pressed between a pair of rollers (11, 212) or plate-shaped press members (331) each having its press surface formed from a rigid porous material (6, C, 331) having water absorption and retention properties based on the capillary action; water squeezed from the substance by pressing is permeated into the rigid porous material due to water absorption based on the capillary action or water pressure and the permeated water is retained by virtue of the water retention properties based on the capillary action, thereby dewatering the substance; and the water retained by the rigid porous material is discharged by sending pressurized air to regenerate the capillary tubes.