Abstract: Flow of lean oil to an absorption section of an absorber is controlled responsive to pressure drop at least a portion of said absorption section. Flow of lean oil can be maximized, short of flooding, responsive to said pressure differential. Apparatus is also described.

Abstract: In a storage system for liquefied gases at least a portion of the compressed gases from the refrigeration system for the storage system are combined with liquefied gases being removed from the storage system to thereby provide heat to liquefied gases being removed from the storage system. This prevents the build up of the light components of the liquefied gases in the storage system and also conserves energy.

Abstract: Vapor vented from a liquefied petroleum gas storage container, vessel, or pit is compressed, cooled, and condensed. The condensate is admixed with liquefied petroleum gas taken from said storage and the admixture thus obtained is returned to said storage.

Abstract: Process for re-refining used lubrication oil by contacting the used lube oil in a first extraction zone with a light hydrocarbon solvent, for example, propane, yielding a first extract and raffinate. The solvent is removed from the first extract to recover desired lubrication stock base. The first raffinate is then solvent-extracted, using the same solvent to produce a second extract and raffinate. The solvent is then removed from this second extract to yield an oil which can be further refined for separation of valuable constituents or burned as fuel oil. The second raffinate is flashed to remove any remaining solvent and leave an easily discardable solid residue.

Abstract: Deposition of ammonium chloride from gaseous streams is prevented by maintaining the temperature of the gaseous stream above the deposition temperature for ammonium chloride at operating pressure. The invention is particularly useful in hydrocarbon hydrogen treating processes in which hydrogen recycle streams containing ammonium chloride or ammonium chloride-forming constituents must be recompressed before recycle to the hydrogen treating process.

Abstract: Heavy hydrocarbon materials containing asphalt are separated into three different fractions according to chemical composition, namely, a paraffin-waxy fraction, a resin fraction, and an asphaltene-solids fraction, by a process comprising two-stage solvent treatment at different solvent-to-feed ratios and different temperatures. In another embodiment, a fourth product comprising an asphalt fraction can be produced by blending a portion of the resin fraction with a portion of the raffinate obtained from the first solvent extraction fraction stage.