Abstract: A method is provided for increasing the lifetime of Stretford solution by reducing or eliminating the generation of undesirable thiosulfate salts. The method has three major aspects. First, thiocyanate is added to the Stretford solution. Second, the concentration of sodium sulfate in the solution is maintained at a level below about 100 g/l. Third, the solution should contain little or no thiosulfate at the start of operations. It has been found that little or no thiosulfate is generated when the Stretford unit is operated under these conditions. The concentration of sodium sulfate in the solution is maintained at a level below about 100 g/l by removing sodium sulfate from the solution by cooling a slipstream of the solution to precipitate the sodium sulfate as Glauber's salt.

Abstract: A method for removing selenocyanate from aqueous waste water containing a reducing agent by adding a water soluble cupric salt, said waste water containing a reducing agent having a potential to reduce the cupric ion to the cuprous ion, and removing the resulting selenocyanate precipitate from said waste water.

Abstract: A high aromatic, low sulfur No. 2-D diesel fuel, which, upon combustion, provides emission benefits at least equivalent to a 10 vol. % aromatics, low sulfur diesel fuel contains, in addition to more than 10 vol. % aromatics, at least one of(1) a Cetane number less than 55;(2) a nitrogen content of at least 500 ppmw;(3) a sulfur content of at least 250 ppmw; and(4) a polycyclic aromatics content of at least 5.0 wt. %.

Abstract: A process and system for simultaneously cooling shale ash fines and flue gas produced during the combustion of spent shale. The flue gas and fine solids are introduced into a heat exchange zone for contact with conventional heat exchange tubes. Heat transfer particles are introduced into the heat exchange zone for mixing with the flue gas to provide increased heat transfer rates between the flue gas and heat exchange equipment. The heat transfer solids are also of a sufficient size to provide continual scrubbing of the heat exchanger surfaces to prevent the build up of an insulating layer of fine dust particles. A staged cooling system and process is also disclosed.

Abstract: An asphalt blend in which a butadiene-styrene elastomeric block polymer can easily be dispersed at between about 325.degree. F. and about 400.degree. F. and, after cooling, forms a stable material useful as a roofing composition and having a flash point of greater than about 450.degree. F., said blend being composed of a propane extracted asphalt and from about 5 weight % to about 45 weight % of a fluid bed catalytic petroleum cracker bottoms oil comprising a major proportion of oils boiling above 700.degree. F. and, optionally, a minor proportion of oils between about 350.degree. F. and 700.degree. F.

Abstract: An improved process and system for drying moist particulate carbonaceous materials. The invention has particular application to staged drying processes wherein the particulate material is entrained in one or more serially connect hot gas streams having a temperature above the degradation point of the carbonaceous material. The improvement includes providing contactors between the stages which intimately mix and contact the variously sized particles resulting in partial cooling of the smaller hot and dry particles and partial heating of the larger cool and relatively moist particles. The contactor may be provided by a rotating drum, moving bed, fixed bed or fluidized bed. The contactors prevent overheating of small particles during moisture removal and reduce hydrocarbon loss from small particle devolatilization.

Abstract: In processes for retorting oil shale using recycled heat carrying ceramic balls having a critical heat flux value, efficient operation, without heat shock damage to the balls, is obtained by operating at a weight ratio of balls to shale which is greater than but substantially equal to the ratio corresponding to the critical heat flux value; and this ratio is a function of both the heat transfer coefficient at the inlet to the retort and also the difference in temperature between the heat carrying balls and the oil shale. Implementing apparatus includes arrangements for controlling the ratio of heat carrying balls to shale, as by ball feed control apparatus and/or oil shale feed control apparatus, in accordance with the difference in temperature between the ceramic balls and the shale.

Abstract: Pyrolysis process and system for recovering product gases and liquids from solid carbonaceous particles.Dual stage fluidized bed retort is disclosed having frusto-conical stages serially connected to promote uniform pyrolysis. Product gases and oil are removed from final fluid bed stage in series. Process includes various energy efficient aspects involving recycle of dilute phase combusted solids as the heat carrier, heavy oil recycle and use of steam and/or product vapors as the source of fluidizing gas for the staged retort.

Abstract: A dual stage combustion system and process for achieving high fuel combustion efficiency and reduced nitric oxide emissions. Combustion is carried out in two stages. A first partial combustion carried out in an oxygen deficient atmosphere followed by a second complete carbon combustion in an oxidizing atmosphere. The second combustion step achieves complete fuel utilization, but generates a nitrogen oxide containing flue gas. The nitrogen oxide containing flue gas is passed to the first combustion step where it is removed by interaction with the partially combusted solids.

Abstract: An improved apparatus and method for feeding heat carrying solids into a solids heater. A feed conduit is provided which may be removably attached to a solids heater shell. The mounted feed conduit includes an outlet portion disposed within a heating chamber which is defined by the heater shell. A jacket tube is sealed around the feed conduit to provide cooling against high temperatures. Further, inlets and outlets are provided for introducing and removing cooling medium from the cooling zone defined by the space between the jacket tube and feed conduit. The feed conduits are removably attached to the heater shell by way of mounting tubes located in the heater shell roof. For inclined heater shell roofs, the length of the mounting tubes are varied to provide common elevational mounting of a single uniform removable feed conduit.

Abstract: Improved process and system for reducing the amounts of hydrogen sulfide emitted during pyrolysis of oil shale. At the elevated temperatures of oil shale pyrolysis, iron pyrite is converted to hydrogen sulfide which is emitted with the product gases and oils. Reduction in hydrogen sulfide emissions is accomplished by treating the oil shale with ultraviolet radiation of a particular wave length prior to pyrolysis in the presence of oxygen to selectively oxidize the pyritic sulfur to sulfate sulfur. The treated oil shale is then retorted at conventional temperatures. The sulfate sulfur does not decompose or otherwise convert to hydrogen sulfide at these temperatures. The sulfate sulfur remains in the spent shale residue and is discarded as waste to thereby effectively reduce the amount of sulfur emitted as hydrogen sulfide in the pyrolysis product gases.

Abstract: A process for preheating oil shale in which the oil shale is partially preheated to 200.degree. F. to 400.degree. F. in a first lift pipe followed by final preheat to temperatures of between 400.degree. F. and 650.degree. F. in a second lift pipe. Hydrocarbons released from the oil shale in both the first and second lift pipes are incinerated in an incinerator/recuperator. In order to provide adequate incineration and combustion of the hydrocarbons released in the first, low temperature lift pipe, the entrainment gas or first gas stream is a low Btu gas preferably produced from conventional gasification of carbonaceous material. The low Btu entrainment gas along with released hydrocarbons is utilized as a fuel in the incinerator/recuperator and also may be utilized for other combustion applications in oil shale pyrolysis processing. In oil shale pyrolysis carried out with ceramic balls as heat exchange bodies, a portion of the low Btu entrainment gas is conveniently utilized to fuel the ball heater.

Abstract: In processes for retorting oil shale using recycled heat carrying ceramic balls having a critical heat flux value, efficient operation, without heat shock damage to the balls, is obtained by operating at a weight ratio of balls to shale which is greater than but substantially equal to the ratio corresponding to the critical heat flux value; and this ratio is a function of both the heat transfer coefficient at the inlet to the retort and also the difference in temperature between the heat carrying balls and the oil shale. Implementing apparatus includes arrangements for controlling the ratio of heat carrying balls to shale, as by ball feed control apparatus and/or oil shale feed control apparatus, in accordance with the difference in temperature between the ceramic balls and the shale.

Abstract: An improved rotating retort seal having integral bearings for aligning the retort seals relative the sealing surface on the rotating vessel portion of the retort. The sealing function and bearing or seal alignment function are separated to extend seal life and improve sealing. Radial alignment bearings and axial alignment bearings are provided for continually positioning the seal assembly housing during sealing surface nutation. The sealing elements, which are fixed relative to the alignment bearings, is thereby continually aligned and realigned in response to sealing surface nutations during retort rotation. The alignment bearings are extended radially outward from the seals on the sealing surface to prevent damage of the bearings by materials processed in the retort. A lubrication passageway is placed between the alignment bearings and seals to provide for common lubrication of both alignment bearings and seals.

Abstract: A hydrostatic retort seal for sealing to a seal disc on the rotating vessel portion of a rotating retort. An annular caliper assembly is mounted concentrically around the seal disc. The annular caliper assembly includes a body portion having two arms. Each arm on its interior surface includes an annular sealing channel which is filled with liquid under pressure to provide a liquid interface seal layer between the caliper assembly arms and the seal disc. The sealing channels are movable laterally relative each other and are biased inward so that the distance between the two channels or seal layers may be adjusted continually to accommodate nutations and other variations of the rotating seal disc. The caliper assembly is mounted to the stationary retort portions by way of gimbals to allow universal movement of the caliper as it responds to sealing disc nutations. To complete the retort seal, a flexible seal boot is provided between the caliper assembly and stationary retort portion.

Abstract: A method for removing nitric oxide from gas streams containing same. The nitric acid is removed by contacting the nitric oxide with elemental iron in the presence of water. The nitric oxide is believed to be reduced to nitrogen gas. The method has particular applications to removal of nitric oxide from gas streams produced during combustion of carbonaceous materials.

Abstract: An improved method for retorting oil shale with heat-carrying bodies comprising relatively coarse attrition resistant, non-oil sorbing, shale ash particles wherein oil recovery is maximized. After retorting, the spent oil shale and heat-carrying bodies are transferred to a reheating vessel or combustor. The reheating vessel contains a dense phase fluidized bed wherein the fixed carbon contained in the spent shale is combusted at temperatures between 1100.degree. F. and 1600.degree. F. to reheat the heat-carrying bodies. The invention is based on the finding that the decomposition of kerogen, which is present as a binder in raw oil shale, leaves pores within kerogen-rich shale which results in relatively large surface areas. Attrition of the kerogen-rich shale in the dense phase fluidized bed at a superificial gas velocity of 7-14 ft/sec reduces the size of this porous, friable material and allows it to be removed in the exit gas stream as fines.

Abstract: The present invention relates to a method for removing zinc from solid carbon black, preferably obtained from the pyrolysis of rubber, said carbon black containing at least 3%, by weight, of zinc, calculated as ZnO, said method including the steps of contacting the carbon black at a temperature of at least 750.degree. C. with a gas selected from chlorine and hydrogen chloride to form gaseous zinc chloride from the zinc contained in said carbon black, and separating the gaseous zinc chloride from the solid carbon black.

Abstract: A single retort and accumulator structure includes two heating zones for successively removing volatile material from dried crushed coal so that the resultant calcined char has less than about 7 weight percent volatile material and is suitable as a raw material for producing formcoke. In the first zone (carbonizing zone) heat carrying solids are introduced with crushed coal to heat the powdered coal to a temperature in the order of about 800.degree. F. to 1000.degree. F. and produce a carbonized char containing about 10% to 20% by weight of volatile material. The resultant carbonized char is fed onto a trommel, or rotating cylindrical or tapered screen, and the char passes through the screen into a calcining fluidized bed zone. The fluidized bed is maintained by upwardly directed jets of an oxygen containing gas and steam. The temperature of the fluidized bed zone is in the vicinity of about 1200.degree. F. to 1600.degree. F.

Abstract: Petroleum coke containing inorganic compounds including vanadium is gasified with steam in the presence of an alkali metal salt gasification catalyst to produce a combustible gas and an inorganic ash composed primarily of said inorganic compounds and a water soluble alkali metal vanadate and the inorganic ash is placed in a sufficient amount of water to dissolve the vanadate compound and then is recovered by conventional means.