Abstract: A process for cracking lignin-containing feed materials, such as precipitated from black liquor, to produce hydrocarbon products such as ethylene, utilizing dual fluidized beds of particulate solids in series flow arrangement. In the process, the feedstock is introduced with a diluent gas such as steam into the first or fast fluidized bed for cracking reactions at superficial gas velocity exceeding about 5 ft/sec. A particulate solids carrier material, which can comprise at least partly coke produced in the process, is circulated between the beds, and coke deposited on the carrier in the first or cracking bed at 1000.degree.-1600.degree. F. temperature is burned off in a second or combustion bed maintained at 1400.degree.-2000.degree. F. temperature by an oxygen-containing gas and diluent steam introduced therein. Superficial upward gas velocity in the fast fluidized bed zone exceeds about 5 ft/sec. and the bed density exceeds about 3 lb/cu.ft.

Abstract: Carbonaceous solid material such as coal is gasified in a fast fluidized bed gasification system utilizing dual fluidized beds of hot char. The coal in particulate form is introduced along with oxygen-containing gas and steam into the fast fluidized bed gasification zone of a gasifier assembly wherein the upward superficial gas velocity exceeds about 5.0 ft/sec and temperature is 1500.degree.-1850.degree. F. The resulting effluent gas and substantial char are passed through a primary cyclone separator, from which char solids are returned to the fluidized bed. Gas from the primary cyclone separator is passed to a secondary cyclone separator, from which remaining fine char solids are returned through an injection nozzle together with additional steam and oxygen-containing gas to an oxidation zone located at the bottom of the gasifier, wherein the upward gas velocity ranges from about 3-15 ft/sec and is maintained at 1600.degree.-200.degree. F. temperature.

Abstract: An ash containing heavy bitumen recovered from the deashing step of a coal liquefaction process is subjected to vacuum flashing to provide a residual product having a softening point of no less than 350.degree. F. and no greater than 550.degree. F. Subsequently, the flashed product is solidified and pulverized so that 100 percent passes through a 100 mesh screen. The pulverized fraction, without prior coking thereof, is entrained in a gas stream and then subjected to gasification.

Abstract: Solids are separated from a tar sands extract by gravity settling or centrifugation in the presence of a liquid promoter which promotes and enhances the separation of the solid material. The liquid promoter has a characterization factor of at least 9.75, a 5 volume percent distillation temperature of at least 250.degree. F and a 95 volume percent distillation temperature of at least 350.degree. F and no greater than 750.degree. F. As a result, liquid product is obtained without the necessity of preliminary coking of the entire extract.

Abstract: Insoluble material is separated from a coal liquefaction product by gravity settling in the presence of a promoter liquid having specific characteristics, with a portion of the solid containing underflow being recycled to the gravity settler and introduced at a point above the introduction of the coal liquefaction product, with the respective points of introduction being separated by a distance of at least 0.1 H and no greater than 0.5 H wherein H is the total height of the gravity settler.

Abstract: Insoluble materials are separated from a coal liquefaction product having a quinoline insoluble content of greater than 15 wt. % by diluting the product with a diluent which is a solvent for the components which are quinoline soluble and benzene insoluble, with the diluent being added in an amount to provide a mixture having a quinoline insoluble content of no greater than 13 wt. %. Insoluble material is then separated by gravity settling in the presence of a promoter liquid having a 5 volume percent distillation temperature of at least 250.degree. F and a 95 volume percent distillation temperature of at least 350.degree. F and no greater than 750.degree. F, with the promoter liquid having a characterization factor of at least 9.75.

Abstract: In the liquefaction of a sub-bituminous and/or lignitic coal, prior to the liquefaction, the coal is soaked at a temperature of from 550.degree. to 750.degree. F and a pressure of from 30 to 300 psig for a time sufficient to remove at least 10% of the organic oxygen present in the coal to thereby reduce the hydrogen requirements of the liquefaction. The liquefaction is effected with a pasting solvent derived from the sub-bituminous and/or lignitic coal having a 5 volume percent distillation temperature of at least 550.degree. F and containing at least 25 weight percent of material boiling above 800.degree. F. The use of such a pasting solvent provides for improved dispersion of the coal particles during the liquefaction.

Abstract: In the oxidative leaching of copper ores with a silver catalyst initially dissolved in the leaching liquor, all or a portion of the silver precipitates and is recovered with the tailings. Elemental sulfur is extracted from the tailings, and the tailings are treated with concentrated sulfuric acid in the presence of oxygen to recover silver values for recycle to the leaching.

Abstract: Insoluble material is separated from a coal liquefaction product by gravity settling in at least two gravity settlers, with overflow from a previous settler being used as feed to the subsequent settler. A promoter liquid having characterization factor of at least 9.75, a 5 volume percent distillation temperature of at least 250.degree.F and a 95 volume percent distillation temperature of at least 350.degree.F. and no greater than 750.degree.F. is employed in each settler.

Abstract: Insoluble material is separated from a coal liquefaction product by gravity settling in the presence of a specified promoter liquid. The settling is effected to recover a net underflow having a specified ash content and the underflow is stripped of valuable products. By controlling the ash content of the underflow, loss of valuable product in the underflow can be minimized.

Abstract: A coal liquefaction product is separated into an essentially solid free stream and a solid containing stream including the coal ash. The solid containing stream is hydrotreated, in the absence of added catalyst, and valuable clean fuel components stripped from the hydrotreated stream. The combustibles content of the stripped solid containing stream is reduced by hydrotreatment, prior to stripping.

Abstract: Coal is hydroliquefied with the hydrogen consumption being limited to that required for effective liquefaction and/or deashing. Ash is removed and the liquid coal product hydrotreated in a second stage to produce synthetic crude.