Abstract:
Disclosed is a burner for the partial combustion of a solid carbonaceous fuel wherein coal, e.g., finely divided coal, is supplied to a reactor space via a central channel disposed along the longitudinal axis of the burner, and oxygen-containing gas is supplied via an annular channel surrounding said central channel, and heat from the combustion is removed from the hollow front face of the burner by coolant flowed through said front face spirally about the longitudinal axis of the burner.
Abstract:
A process burner for combusting a fluid feed material which has central, middle and frusto-conical conduits in which the central and middle conduits form an annular passageway having an enlarged upstream end forming a distribution chamber to prevent high fluid flow regions which would erode an acceleration conduit at the discharge ends of the central, middle and frusto-conical conduits, the acceleration conduit forming a smooth curving surface without sharp angles from the frusto-conical conduit apex to the cylindrical discharge portion of the acceleration conduit. The distribution chamber preferably has a baffle or mixing plate angularly disposed under the fluid feed inlet to the annular passageway so that the fluid feed changes from axial to downwardly spiralling radial flow.
Abstract:
Synthesis gas is produced by the partial oxidation of a feedstock comprising sulfur-containing petroleum coke and/or liquid hydrocarbonaceous fuel and having ashes that contain nickel and a comparatively low level of silicon. The production of toxic nickel subsulfide (Ni.sub.3 S.sub.2) in the slag is prevented, and there is substantially no increase in the mole ratio H.sub.2 S+COS/H.sub.2 +CO in the raw product gas stream by introducing an additive comprising about 2 to 100 wt. % of a sulfur-containing material and any remainder comprising a supplemental iron-containing material into the reaction zone along with the feed. The additive combines with substantially all of the nickel constituents and most of the iron constituents and sulfur found in the feedstock to produce molten slag substantially comprising a fluid sulfide phase and a relatively minor amount of an Fe, Ni alloy phase. In another embodiment, a minor amount of a calcium compound is included with the additive at startup to reduce the softening temperature of the iron-containing addition agent. In still another embodiment, the additive is uniformly dispersed in sulfur-containing petroleum coke having a nickel-containing ash. By this method molten slag free from toxic Ni.sub.3 S.sub.2 and having a reduced viscosity may be readily removed from the gas generator at a lower temperature. Further, the life of the refractory lining is extended.
Abstract:
An ash fusion temperature increasing agent principally comprising a silicon and/or titanium compound, such as SiO.sub.2 and/or TiO.sub.2 is mixed with an ash-containing fuel comprising a pumpable liquid hydrocarbonaceous material and/or petroleum coke to produce Mixture A. In one embodiment, the ash fusion temperature increasing agent comprises about 55-100 wt. % of silicon compound selected from the group consisting of fine silica or quartz, volcanic ash, and mixtures thereof; and the remainder, if any, of said ash fusion temperature increasing agent comprises a member of the group consisting of aluminum compound such as Al.sub.2 O.sub.3, magnesium compound such as MgO, and mixtures thereof. Mixture A is reacted with a free-oxygen containing gas in a free-flow refractory lined reaction zone of a partial oxidation gas generator. A hot raw effluent gas stream comprising H.sub.2 +CO along with fly-ash having an increased initial deformation temperature are produced at a higher temperature. Alternatively, Mixture A may be first introduced into a coking zone and converted into petroleum coke in which the ash fusion temperature increasing agent is dispersed throughout. The petroleum coke entrained in a liquid or gaseous carrier is then introduced into the partial oxidation gas generator where a hot raw effluent gas stream comprising H.sub.2 +CO is produced along with fly-ash having an increased ash fusion temperature. The fly-ash is readily separated from the effluent gas stream; and, the gas generator may be operated in the fly-ash mode at a higher temperature, thereby yielding higher carbon conversions while extending the life of the refractory lined reaction zone.
Abstract:
Aqueous slurries of solid carbonaceous fuel having an increased reactivity of the solid material are produced by maintaining the solid carbonaceous fuel-water slurry at a temperature in the range of about 300.degree. to 650.degree. F. and a pressure in the range of about 100 to 3500 psia and sufficient to maintain the H.sub.2 O in the slurry in liquid phase; at substantially constant temperature depressurizing said slurry to a pressure in the range of about above atmospheric to 250 psia above that in the reaction zone of a partial oxidation gas generator, thereby partially vaporizing the water in the slurry and producing steam. After depressurizing, the slurry is cooled so that the solid particles drop in temperature about 2.degree. F. to 10.degree. F. and the water in the slurry drops in temperature about 100.degree. F. to about 200.degree. F. the upgraded solid carbonaceous fuel-water slurry is then introduced into the reaction zone of the gas generator with substantially no further charge in pressure and/or temperature except for that resulting from ordinary pressure and/or heat losses in the lines. By the partial oxidation of the upgraded stream of solid carbonaceous fuel-water slurry with a free-oxygen containing gas in the gas generator, synthesis gas, reducing gas, or fuel gas is produced with a greater efficiency.
Abstract:
Control process for producing an aqueous slurry of solid carbonaceous fuel having a desired solids concentration for feed to a partial oxidation gas generator by grinding together in a size reduction zone a recycle aqueous slurry stream comprising carbon-containing particulate solids, a stream of solid carbonaceous fuel, and a specific amount of make-up water. No valves are in the line or path between the size reduction zone and the feed tanks for the solid carbonaceous fuel and recycle aqueous slurry. A system control unit automatically calculates the amount of make-up water and provides a corresponding signal to control the flow rate. Input signals that are provided to the system control unit include those corresponding to the weigh belt feeder speed and moisture content for the solid carbonaceous fuel; and pump speed, weight fraction, temperature, and density of the solids for the slurry of recycle particulate solids.
Abstract:
The present invention relates to a method for producing pumpable coal-water suspensions by grinding pre-comminuted coal with water in a packed column in a ratio corresponding to the composition of the suspension ready for use. The addition of water or coal is controlled by measuring the density of the suspension leaving the mill, and the grain size of the coal particles is controlled by measuring the viscosity of the suspension. The density and viscosity of the coal-water suspension are simultaneously mutually adjusted. The addition of additives to the water is regulated according to the amount of coal added to the mill. The coal-water suspension can be fed to a coal gasification reactor without substantially changing the relative amounts of coal and water in said suspension.
Abstract:
Disclosed is a partial oxidation process for producing synthesis gas, fuel gas or reducing gas from slurries of solid carbonaceous fuel and/or liquid or gaseous hydrocarbon fuel. The burner has a high turndown feature and comprises a central conduit; a central bunch of parallel tubes that extend longitudinally through said central conduit; an outer conduit coaxial with said central conduit and forming an annular passage therewith; and an annular bunch of parallel tubes that extend longitudinally through said annular passage; and wherein the downstream ends of said central and annular bunches of parallel tubes are respectively retracted upstream from the burner face a distance of about 0 to 12 i.e. 3 to 10 times the minimum diameter of the central exit orifice and the minimum width of the annular exit orifice. Three ranges of flow through the burner may be obtained by using one or both bunches of tubes and their surrounding conduits. Throughput levels may be rapidly changed - up and down - without sacrificing stable operation. Additional mixing of the reactant streams is obtained in one embodiment by providing one or more coaxial cylindrical shaped pre-mix chambers in series in the central conduit and/or one or more annular shaped pre-mix chambers in series in the annular passage.
Abstract:
A process for the partial oxidation of pumpable slurries of solid carbonaceous fuels in which the pumpable slurry of solid carbonaceous fuel in a liquid carrier is passed in liquid phase through one passage of a burner comprising a retracted central coaxial conduit, an outer coaxial conduit with a converging orifice at the downstream tip of the burner and, optionally, an intermediate coaxial conduit. The downstream tips of the central conduit and the intermediate conduit, if any, are retracted upstream from the burner face a distance of respectively two or more say 3 to 10 for the central conduit, and about 0 to 12 say 1 to 5 for the intermediate conduit times the minimum diameter of the converging orifice of the outer conduit at the burner tip. A pre-mix zone is thereby provided comprising one or more, say 2 to 5 coaxial pre-mix chambers in series. The free-oxygen containing stream is passed through a separate passage of the burner into the pre-mix zone, in which mixing takes place with the slurry of solid carbonaceous fuel and liquid carrier. From 0 to 100, say about 2 to 80, volume % of the liquid carrier may be vaporized in the pre-mix zone. The multiphase mixture of reactants is then discharged into the reaction zone of the free-flow partial oxidation gas generator by way of the converging orifice of the outer conduit at the burner tip. Synthesis gas, fuel gas, or reducing gas is thereby produced.
Abstract:
Coal or other carbonaceous material is gasified by reaction with steam and oxygen in a manner to minimize the problems of effluent water stream disposal. The condensate water from the product gas is recycled to slurry the coal feed and the amount of additional water or steam added for cooling or heating is minimized and preferably kept to a level of about that required to react with the carbonaceous material in the gasification reaction. The gasification is performed in a pressurized fluidized bed with the coal fed in a water slurry and preheated or vaporized by indirect heat exchange contact with product gas and recycled steam. The carbonaceous material is conveyed in a gas-solid mixture from bottom to top of the pressurized fluidized bed gasifier with the solids removed from the product gas and recycled steam in a supported moving bed filter of the resulting carbonaceous char. Steam is condensed from the product gas and the condensate recycled to form a slurry with the feed coal carbonaceous particles.