Showing papers on "Raffinate published in 1982"

Recovery of deasphalting solvent

Abstract: The invention is an energy-efficient improvement in a continuous deasphalting process in which a mixture of viscous hydrocarbon oils with resins and/or asphaltenes is contacted with a quantity of pure or mixed hydrocarbon solvents including, but not limited to, propane, butane, pentane, hexane, heptane, isomers thereof, and unsaturated hydrocarbons of similar molecular weights, in order to separate a primary extract phase comprising high viscosity oil, resins and/or asphaltenes, and solvent. The primary raffinate phase is further contacted with an additional quantity of solvent comprising similar components to those in the primary solvent (but not necessarily identical thereto) to separate a secondary extract phase comprising high viscosity oil and solvent, and a secondary raffinate phase comprising resins and/or asphaltenes and solvent. The contacting step may be repeated as often as desired to make additional extract phases which are recovered separately. The solvents from the extract and raffinate phases are separated from the associated viscous oils, resins and/or asphaltenes, and reused in the contacting process. Several embodiments of the invention are disclosed. In each embodiment, the primary and secondary recovery systems are integrated so that heat recovered from the primary solvent is used to operate the secondary recovery system.

Process for the production of electrolytic zinc or high purity zinc salts from secondary zinc raw- materials

Abstract: The present invention relates to a process for the production of either electrolytic zinc or high purity zinc salts from secondary zinc raw materials which comprises: leaching said raw material in a slightly acid aqueous solution at controlled pH, separating the reaction mixture into a leaching liquor containing the leached zinc and a solid residue which after suitable washing is descarted; directing the zinc-bearing liquor to a solvent extraction facility where it is brought into contact with an organic solution containing organic acids as cationic extraction reagents, by means of which, an ion exchange of zinc by hydrogen ions is achieved, resulting in a zinc loaded organic solution and in an aqueous solution containing the stoichiometric acidity to the extracted zinc; recycling the acid aqueous raffinate to the previous leaching step where it is used as the slightly acid aqueous solution to carry-out the zinc leaching from the raw material; sending the zinc organic extract to a stripping facility where it is brought into contact with a strong acid solution of zinc sulphate, by means of which an ion exchange of zinc by hydrogen ions takes place, thus producing a concentrated solution of zinc sulphate and an organic solution free of zinc, containing the stoichiometric acidity to the stripped zinc, which is recycled back to the previous step to perform the zinc extraction; directing the concentrated zinc sulphate aqueous solution either to an electrowinning facility to produce electrolytic zinc, or to a crystallization plant for the production of pure zinc sulphate; recycling back to the previous step of zinc stripping either the spent electrolyte from the electrowinning facility or the mother liquors from the crystallization plant to form, after suitable sulphuric acid make-up, the strong acid solution of zinc sulphate, by means of which zinc stripping from the organic extract is achieved.

Thermally coupled extractive distillation process

Abstract: Thermally coupled extractive distillation; a feed stock (for example, a C4 or C5 cut from an ethylene plant) is distilled by thermally coupled extractive distillation to remove paraffins and mono-olefins as a raffinate stream, as well as acetylenic hydrocarbons in a separate steam, thus segregating the C4 or C5 diolefin, the process using extraction solvents such as acetonitrile (ACN), dimethyl formamide (DMF), furfural, acetone, dimethylacetamide or N-methyl-2-pyrrolidone mixed with 0-12 weight percent of water, a bottoms stream of virtually acetylene free solvent further being produced; thermally coupled extractive distillation utilizing one to three coupled vessels to produce at least two and preferably three discrete, different volatility streams therefrom, as well as an extractive solvent recycle stream.

Separation of C4 olefins

Abstract: A process for the separation of normal C 4 hydrocarbons from isobutylene. A mixture of the normal C 4 hydrocarbons and isobutylene is contacted with a molecular sieve comprising silicalite which is selective for the normal C 4 hydrocarbons. The isobutylene is then recovered in the raffinate stream and the normal C 4 hydrocarbons recovered by displacement with pentene-1.

Process for recovering oxygenated organic compounds from dilute aqueous solutions employing liquid extraction media

Abstract: A thermally efficient process for recovering an oxygenated organic material, such as ethanol, present in dilute aqueous solution is disclosed which comprises contacting said dilute aqueous solution with at least one inert extractant which is liquid at ambient temperature and pressure, said extractant being selected from the group consisting of unsubstituted and substituted cyclic secondary amines and unsubstituted and substituted aromatic cyclic amines having a distribution coefficient of at least about 0.70 or a separation factor of at least about 1.0. The invention further provides a process for obtaining substantially anhydrous oxygenated organic material from a dilute aqueous solution thereof in which the stream is subjected to liquid-liquid extraction to provide an oxygenated organic material poor raffinate phase and an oxygenated organic material rich extract phase, the oxygenated organic material present in said latter phase is concentrated in a rectifying column to provide an aqueous oxygenated organic material of high concentration and, if desired or necessary, the concentrated stream is azeotropically distilled in an anhydrous column operated under substantially superatmospheric pressure with thermal values recovered from said anhydrous column being used to satisfy part of all of the thermal operating requirements of the rectifying column.

Process for recovering ethanol from dilute aqueous solutions employing liquid extraction media

Abstract: A thermally efficient process for recovering ethanol present in dilute aqueous solution is disclosed which comprises contacting said dilute aqueous ethanol solution with at least one inert extractant which is liquid at ambient temperature and pressure, said extractant being selected from the group consisting of unsubstituted and substituted cyclic secondary amines and unsubstituted and substituted aromatic cyclic amines having a distribution coefficient of at least about 0.70 or a separation factor of at least about 1.0. The invention further provides a process for obtaining substantially anhydrous ethanol from a dilute aqueous ethanol solution in which the ethanol stream is subjected to liquid-liquid extraction to provide an ethanol-poor raffinate phase and an ethanol-rich extract phase, the ethanol present in said latter phase is concentrated in a rectifing column to provide an aqueous ethanol of high proof and the concentrated ethanol is azeotropically distilled in an anhydrous column operated under substantially superatmospheric pressure with thermal values recovered from said anhydrous column being used to satisfy part of all of the thermal operating requirements of the rectifying column.

Process for removal of hydroxy and/or mercapto-substituted hydrocarbons from coal liquids

Abstract: Removal of hydroxy-substituted and/or mercapto-substituted-hydrocarbons from coal liquids which comprises contacting the coal liquids with an aqueous composition containing an alkanolamine, thereby providing a two-phase mixture, and then separating the mixture into an aqueous extract phase and a naphtha rich raffinate phase.

Recovery of metal values from sulphide concentrates

Abstract: A process for recovering non- ferrous metal values from a sulphide concentrate containing at least one non-ferrous metal selected from zinc, copper, lead, cobalt, nickel, silver and gold, as well as iron, comprises leaching the sulphide concentrate in at least one leach stage including a primary leach stage in which the sulphide concentrate is leached under oxidising conditions with an acidic aqueous chloride solution containing calcium chloride, thereby to solubilise non-ferrous metal values in the material and to leave a residue comprising iron in oxide or hydrated oxide form and calcium sulphate, passing resulting non-ferrous metal- containing chloride leach liquor to an ion exchange stage in which non- ferrous metal values are recovered by cation exchange, maintaining pH conditions in the ion exchange stage favourable for cation exchange by addition of a pH control agent comprising a material selected from CaO, Ca(OH)2, CaCO3, and mixtures thereof, and recycling an aqueous calcium chloride-containing raffinate from the ion exchange stage to the primary leach stage.

Zeolite adsorbent for separation of para-xylene

Abstract: Para-xylene may be recovered as raffinate by contacting a C-8 aromatic hydrocarbon mixture, in the presence of toluene desorbent, with a synthetic crystalline lithium aluminosilicate zeolite HP (formed by ion exchange from a sodium aluminosilicate zeolite HP having a lattice constant of 25.02-25.10 Å)--preferably in the presence of a pyridine.

Process of extracting a metal value

Abstract: To extract a metal value, particularly aluminium, from an aqueous feed stream containing the value to be extracted is treated in a recovery unit from which it passes to a contactor where it is contacted with a solvent stream including a partially water soluble extractant for the value and an organic diluent. The delivery from the contactor is separated into an organic phase, an aqueous raffinate and a dispersed intermediate phase. The organic phase is stripped of the value and recycled to the solvent stream. The raffinate as recycled by being added to the feed stream, and the intermediate phase is treated for recovery of extractant.

Preparation of electric insulation oil

Abstract: PURPOSE:To provide an electric insulation oil having a small S content and high oxidation stability, by hydrogenation refining followed by solvent refining before the dewaxing treatment of a specific distillate of a paraffin base crude oil or mixture base crude oil. CONSTITUTION:A distillate having a boiling point (converted into normal pressure) of 250-400 deg.C which is obtained by the distillation at normal pressure of paraffin base crude oil or mixture base crude oil or by the distillation at a reduced pressure of residual oil of the normal pressure distillation of the same crude oil is hydrogenation-refined in the presence of a catalyst such as Ni or the like supported on a carrier such as alumina, etc. at 310-370 deg.C to desulfurize 50-80wt%, and then the resulting hydrogenation refined oil is desulfurized 40-80wt% by the solvent refining employing furfural, etc. to obtain raffinate. Subsequently, the raffinate is subjected to a solvent dewaxing treatment and, if necessary, to a clay treatment in succession to obtain an electric insulation oil having an S content of 0.1- 0.4wt%.

Production of methylnaphthalenes and tar bases including indole

Abstract: Methylnaphthalenes, indole and other tar bases are recovered from a base-extracted coal tar distillation fraction. In one form, an aqueous salt solution of pH 0.5-3 extracts other tar bases from the starting material, and thereafter both products are recovered from the raffinate by several alternate methods including ethylene glycol extraction and extractive distillation. In other forms, the starting material is extracted with ethylene glycol and the extract is distilled to recover several products including indole. The raffinate of ethylene glycol extraction contains methylnaphthalenes and other hydrocarbons and can be purified to solvent-grade material.

Pretreatment of catalytic dewaxing feedstocks

Abstract: Catalytically dewaxed lubricating base stock oils that have improved resistance to oxidation are produced by pretreating the waxy furfural raffinate with a zeolite sorbent prior to dewaxing with a zeolite catalyst such as ZSM-5, and conducting the dewaxing at a reduced temperature not to exceed about 357°C to731°C (650° to 700°F).

Solvent-extraction studies of coprocessing flowsheets: results from campaigns 1 and 2 of the Solvent-Extraction Test Facility (SETF)

Abstract: The Solvent Extraction Test Facility (SETF) was installed in one of the heavily shielded cells of the Transuranium Processing Plant during 1978. This facility contains dissolution, feed preparation, solvent extraction (three 16-stage mixer-settlers), and plutonium product handling equipment, as well as waste solution tanks. Irradiated fuel from the H.B. Robinson-2 Pressurized Water Reactor was processed in the first two campaigns of experimental work, which were completed in 1979. The objective was to test a variety of coprocessing flowsheets. Areas of the solvent extraction process that received special attention included (1) crud formation, particularly in the extraction contactor; (2) uranium and plutonium losses in the extraction raffinate; (3) fission product decontamination; (4) reduction of tetravalent plutonium, particularly by means of hydroxylamine nitrate or nitrous acid; (5) costripping of uranium and plutonium; (6) partial partitioning; and (7) solvent degradation.

Oxidation stable base oil

Abstract: A base oil composition comprising: (a) a base oil having a viscosity index of at least 94 obtained by hydrotreating a solvent-extracted raffinate having a viscosity index of at most 92, and (b) a solvent-extracted raffinate having a viscosity index of at most 92, and/or a deasphalted vacuum residue and/or a hydrotreated deasphalted vacuum residue. shows improved oxidation stability.

Reduction of iron in a reductive stripping process for the recovery of uranium from wet process phosphoric acid

Abstract: A two stage reductive stripping process for recovering uranium from wet process phosphoric acid, wherein the ferrous ions required for the first-stage reductive strip are supplied by heating a portion of acid raffinate phosphoric acid from the first-stage extraction in the presence of pressurized hydrogen gas. The pressurized hydrogen gas reduces the ferric ions in the raffinate to the ferrous state without any addition of metallic iron or other impurity, so that the uranium-enhanced reductive strip solution supplied to the second stage from the first stage reductive strip has a low concentration of iron impurity, and no further purification to remove iron impurity is required.

Liquid fuel composition

Abstract: PURPOSE:A cheap liquid fuel for a rocket engine with excellent stability with time, prepd. by compounding specified hydrocarbon oils, i.e., a naphthenic hydrocarbon oil and an isoparaffinic hydrocarbon oil formed in the petroleum refining industry as a byproduct. CONSTITUTION:A hydrocarbon oil obtd. by the nuclear hydrogenation to a hydrogenation degree >=95%, of a heavy fraction of b.p. 240-350 deg.C formed as a byproduct in the preparation of a high-octane gasoline by the catalytic conversion by naphtha on a Pt catalyst is mixed with a hydrocarbon oil composed of a residue, i.e., a raffinate of b.p. 185-315 deg.C and arom. content <=5% prepd. by separating a straight-chain hydrocarbon from a kerosine fraction, in a proportion of 1/5-5/1.

Process for refining waste liquor

Abstract: Aqueous mother liquor from which pentaerythritol has been removed by crystallization is extracted with tetrahydrofuran to remove formals, and the raffinate comprising pentaerythritol is recycled to the crystallization process.

Principal conversions of hydrocarbons in hydrotreating distillate lube raffinate

Abstract: This article reports on a study of the principal conversions of hydrocarbons in hydrotreating a raffinate from phenol treating, obtained from a mixture of Volga-Ural and West Siberian crudes. It examines naphthenic hydrocarbons, alkylbenzenes, naphthalene hydrocarbons, and phenanthrenes. The degree of conversion of all groups of the aromatic hydrocarbons is considerably greater than the degree of conversion of the naphthenes. The greater the conversion of aromatics, the more significant are the changes in their physicochemical properties. Substantial decreases in the viscosity, density, and refractive index, and increases in the viscosity index are observed.