Texaco Inc.

Robert J Stellaccio

Mitri S Najjar

Robert M Suggitt

Albert Brent

Donald Duane Brooker

Henry C Chan

Michael M Dach

Jerrold S Kassman

The present invention provides a process whereby a high viscosity hydrocarbonaceous material is fed to a gasifier for conversion to synthesis gas. The feedstock, steam, oxygen, and recycled gasification system water are all fed into the gasifier through a four stream feed injector. The feedstock in this design is sandwiched between two oxygen streams so as to provide better conversion for the exceptionally heavy feed. The fourth stream down the central bayonet of the feed injector provides the flow path for the recycled water.

Process for the gasification of heavy oil

A partial oxidation process and a novel burner are provided for simultaneously introducing two or three separate feedstreams into a free-flow partial oxidation gas generator for the production of synthesis gas and fuel gas, or reducing gas. The reactant feedstreams include a liquid hydrocarbonaceous fuel or a pumpable slurry of solid carbonaceous fuel, and a free-oxygen containing gas e.g. air or oxygen. The burner comprises a central conduit and a plurality of spaced concentric coaxial conduits with down-flowing annular passages. A flat annular-shaped disc or cup-shaped porous ceramic or porous metal cooling means of uniform composition, wall thickness and porosity with the various pores interconnecting is attached to the downstream tip of the burner. A controlled amount of liquid coolant under pressure is passed successively through the porous inside surface, porous core and porous outside surface of the cooling means is vaporized. The tip of the burner is thereby cooled. Stress cracking of the burner tip is prevented; and the life of the burner is extended. Further, deposition of ash on the face of the burner is prevented.

Partial oxidation process and burner with porous tip

This process pertains to a achieving high on-stream time and maintaining the temperature and composition of the raw effluent gas stream from a partial oxidation gas generator being fed simultaneously with a stream of gaseous fuel and separate stream of liquid hydrocarbonaceous fuel. Two parallel oxygen streams equipped with flow transmitters and control valves are used to supply the oxygen associated with two separate and different fuel streams. Each stream of oxygen is controlled by an O.sub.2 /fuel ratio control so that if the flow rate of either stream of fuel or its related oxygen stream changes, the oxygen/carbon atomic ratio of the remaining O.sub.2 and fuel stream in the gasifier is maintained at a desired value. Further, if either fuel flow is stopped, its associated O.sub.2 flow will stop, but the remaining fuel stream and its associated O.sub.2 stream will continue to flow at the same rate with no change in the oxygen/fuel weight ratio. Complete shut down of the unit is thereby avoided. The quick raising of reactor temperatures to unsafe levels due to excess oxygen that occurs when one of the fuel streams is lost is thereby prevented.

Partial oxidation process

A burner for operating in a high temperature and high pressure atmosphere such as in a fuel burning gasifier, requires a high degree of cooling such as by water circulation through the burner. In the event of physical breakage or damage to the normal cooling system, means is provided for introducing a higher pressure coolant into the system. The latter fills the system, both upstream and downstream of the cooling coil, to permit progressive discontinuance of the burner operation without substantial damage. It further avoids the backflow of gas from the high pressure gasifier which would otherwise be discharged to flow back through the cooling system and be discharged into the atmosphere thereby creating a dangerous as well as a harmful environment.

Cooling system for gasifier burner operating in a high pressure

Low sulfur, iron and calcium containing solid carbonaceous fuel having a high melting point ash is mixed with a sufficient amount of iron sulfide containing material or supplemental iron and sulfur containing reactant materials that react in the reaction zone to produce iron and sulfur containing compounds. The mixture of materials is reacted in a free-flow gasifier by partial oxidation to produce a raw gas stream of synthesis gas, reducing gas or fuel gas, containing entrained particulate matter including molten slag. By the process, sufficient iron and sulfur are in the reaction zone so that the melting point of the fuel ash is decreased, and the mole ratio H.sub.2 S/H.sub.2 +CO in the raw gas stream is greater than 0.01. Further, the amount of iron in the molten ash is greater than 10.0 wt. %, and preferably at least 14 wt. % of the molten ash. By this means, the fluid temperature of the molten ash entrained in the raw gas stream is reduced at least 100.degree. F. less than the fluid temperature of the fuel ash without the addition of iron and sulfur, and the gasifier may be operated in the molten slagging mode at a lower temperature. Further, coal wash tailings containing iron sulfides may be disposed of as a portion of the feed to the gasifier in an environmentally acceptable manner; and useful by-product sulfur may be recovered.

Coal gasification process

The temperature of a burner in the reaction zone of a partial oxidation gas generator is controlled so that there is substantially no condensation of H.sub.2 O from the hot raw product gas on the surface of the burner. Burner corrosion is thereby reduced. In the method, burner coolant is introduced into the burner at a pressure greater than that in the reaction zone and at a temperature in the range of about 5.degree. to 50.degree. F. higher than the dew point of the raw product gas contacting the burner in the reaction zone. The heated water coolant leaving the burner flows to a pressurized receiving vessel and its temperature is reduced by expansion into a feed vessel. Saturated steam is produced from a portion of the flashed water and is separated in the feed vessel for use as a heat source. Steam condensate is thereby produced and recycled to the feed vessel as make-up. The cooled liquid water coolant is then pumped into the inlet to the burner at a higher pressure than that in the feed vessel. This prevents raw product gas from leaking out of the gas generator by way of any break in the burner cooling water system. In another embodiment, the temperature of the heated water coolant leaving the burner is reduced by direct heat exchange with cooler make-up water.

Method of controlling the temperature of a partial oxidation burner

A burner is provided for introducing four separate feedstreams including a stream of gaseous material from the group free-oxygen containing gas, steam, recycle product gas, and hydrocarbon gas; a pumpable slurry of solid carbonaceous fuel in liquid phase e.g. coal-water; and two high velocity streams of free-oxygen containing gas into a free-flow partial oxidation gas generator for the production of synthesis gas, fuel gas, or reducing gas. The burner has a central conduit and three concentric annular passages. A central core of a gas selected from the group consisting of free-oxygen containing gas, steam, recycle product gas, and hydrocarbon gas surrounded by the slurry of solid carbonaceous fuel is discharged from the central conduit and first annular passage respectively and is impacted by two separate streams of free-oxygen containing gas passing through the second and outer annular passages. With this burner, at least one stream of high velocity free-oxygen containing gas is always available, even at turn-down, to provide atomization and intimate mixing of the slurry feed.

High turn down burner for partial oxidation of slurries of solid fuel

A partial oxidation process including a burner is provided for introducing four separate feedstreams including a stream of gaseous material from the group free-oxygen containing gas, steam, recycle product gas, and hydrocarbon gas; a pumpable slurry of solid carbonaceous fuel in liquid phase e.g. coal-water; and two high velocity streams of free-oxygen containing gas into a free-flow partial oxidation gas generator for the production of synthesis gas, fuel gas, or reducing gas. The burner has a central conduit and three concentric annular passages. A central core of a gas selected from the group consisting of free-oxygen containing gas, steam, recycle product gas, and hydrocarbon gas surrounded by the slurry of solid carbonaceous fuel is discharged from the central conduit and first annular passage respectively and is impacted by two separate streams of free-oxygen containing gas passing through the second and outer annular passages. With this burner, at least one stream of high velocity free-oxygen containing gas is always available, even at turn-down, to provide atomization and intimate mixing of the slurry feed.

Partial oxidation process for slurries of solid fuel

The particulate carbon in a liquid organic extractant-carbon-water dispersion stream that is produced in a decanter is separated as clean, dry carbon particles from the liquid carrier by atomizing the dispersion and vaporizing the liquid organic extractant and water in a spray dryer. Thermal energy for completely vaporizing the liquid carrier is provided by directly contacting the atomized dispersion in the spray dryer with a split stream of hot raw synthesis gas containing entrained particulate carbon from a partial oxidation gas generator. The continuous closed-cycle operation permits recovery and recycle of the water used for cooling and cleaning the stream of raw synthesis gas as well as the recovery and reuse of the liquid organic extractant. Clean dewatered and clean saturated streams of synthesis gas are simultaneously produced along with the by-product clean, dry carbon particles.

Carbon recovery process

A partial oxidation process with an extractant purifier for removing the particulate carbon entrained in a vaporized stream of normally liquid organic extractant-carbon-water dispersion from a decanter and producing a clean vaporized mixture of liquid organic extractant and water and a separate liquid stream of liquid hydrocarbonaceous fuel-carbon dispersion. The extractant purifier comprises a closed, vertical, cylindrical, thermally insulated vessel with an unobstructed central passage. Supported in the upper section of the vessel is a gas-solids separator for separating the particulate carbon from the vaporized dispersion flowing up the vessel and discharging the particulate carbon into atomized liquid hydrocarbon fuel located within the lower section of the purifier.

Partial oxidation process with extractant purification

The hot raw effluent gas stream from a free-flow partial oxidation gas generator comprising H.sub.2, CO, CO.sub.2, entrained particulate carbon, and at least one material from the group H.sub.2 O, N.sub.2, Ar, H.sub.2 S, COS, CH.sub.4, and ash are split into two hot raw gas streams which are separately processed. One hot, raw split gas stream contains about 5 to 50 volume %, such as 10 to 20 volume % of the total amount of hot raw effluent gas stream and the other hot, raw split gas stream contains the remainder. One raw, split gas stream is cleaned by quenching and scrubbing with water to produce a clean product gas stream saturated with water. The entrained particulate carbon is removed from the raw synthesis gas as a carbon-water dispersion from which it is extracted with a liquid organic extractant. The resulting liquid organic extractant-carbon-water dispersion is vaporized in a vaporizing zone using the sensible heat from the other hot raw split gas stream at substantially the same conditions of temperature and pressure as in the gas generator less ordinary losses in the lines. The particulate carbon is then separated from the gaseous phase by scrubbing with a liquid hydrocarbon fuel to separate out a liquid hydrocarbon fuel- carbon dispersion which may be supplied to the gas generator as a portion of the feed. The remaining gaseous mixture is cooled and separated into a clean dewatered product gas stream, water, and liquid organic extractant. The latter two materials are recycled.

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Spring, TX, United States of America

Robert J Stellaccio