Patent GB-733067-A (GB)
Title: Processes for the separation of solid hydrocarbons from mixtures thereof with oil
IPC: C10G73/06
Filed: 1951-12-27
Abstract: Solid naphthalene is separated from a tar oil by mixing with a solvent which, at the working temperature dissolves the oil but not the naphthalene, cooling the mixture, if necessary, to form an oil-solvent phase and a solid naphthalene phase, and contacting the naphthalene phase with an aqueous auxiliary liquid and a surface-active substance so that an oil-in-water emulsion is temporarily formed, whereby the oil-solvent phase separates from the solid naphthalene phase or the naphthalene phase enters the auxiliary liquid phase.  The surface-active substance and the di-electric constants of the two liquid phases are such that the angle between the direction of the interfacial tension of the two liquid phases and the surface of the solid naphthalene phase under equilibrium conditions at a point where the three phases meet, is at least 90 degrees.  Solvents referred to are dichloroethane, methylethyl ketone and benzene or toluene, methylethyl ketone, propane and benzene, and dichloromethane.  The auxiliary liquid is immiscible with the oil-solvent phase at the working temperature and has a higher dielectric constant; liquids referred to are water or the lower alcohols such as methanol and ethanol, glycol or glycerol, mixed with water.  The pH of the auxiliary liquid phase may be adjusted by addition of aqueous NaOH.  Surface-active agents mentioned are preferably cation - active or anion - active substances; examples given are magnesium and sodium heptadecyl-9-sulphates, sodium C23-12-sulphate, alkylaryl sulphonates, dibutylnaphthyl sulphonate and di-isopropyl-naphthyl sulphonate, dioctylbenzyl sulphonate, polyethylene oxide substituted alkylaryl sulphonate, the sodium salt of dioctyl sulphosuccinic acid, the sodium salt of sulphonated oxyethylamine, alkylnaphthalene sulphonate and castor oil, sulphonated ricinoleic acid ester, sodium dodecylbenzene sulphonate, sodium C9-C13 benzene sulphonate, sodium sulphonates obtained in the refining of various mineral oils, sodium naphthenates, oleates and ricinoleates, the hydrochloric acid salts of octadecylamine and dodecylamine, and the substances known under the Trade Names "Breeze," "Triton K," "Lissolamine A," "Fixanol C," "Peregal OK," "Sulphaminol" and "Witol." Salts, such as sodium chloride and calcium chloride or alcohols such as methanol or ethanol may be added to an aqueous auxiliary liquid when working at low temperatures to prevent freezing. Demulsifiers may be added to ease the separation of the solid and liquid phases; examples given are various ammonium, lithium, sodium and potassium, magnesium, calcium, cadmium, zinc, copper, manganese, iron and nickel salts, and sodium sulphate together with cyclohexylamine, phenol, diphenylamine, amyl or dodecyl alcohols, cyclohexanol or substances known under the Trade Names "Lubrol," "Span," "Igepal," "Atlox," "Nonisol" and "Triton."  The dewaxing oil or deoiling wax processes may be carried out by filtering or centrifuging the paraffin wax from the wax solvent phase and washing the oily wax with the auxiliary liquid; in this case the surface-active agent is added to the auxiliary liquid.  A number of other solvents, surface-active agents and demulsifiers are given in comparative examples outside the scope of the invention.  The words "Triton," "Lissolamine," "Fixanol," "Peregal," "Lubrol," "Span" and "Igepal" are Registered Trade Marks.ALSO:Solid hydrocarbons are separated from a mixture thereof with oil by mixing with a solvent which, at the working temperature, dissolves the oil but not the solid hydrocarbons, cooling the mixture, if necessary, to form an oil-solvent phase and a solid hydrocarbon phase, and contacting the hydrocarbon phase with an aqueous auxiliary liquid and a surface-active substance so that an oil-in-water emulsion is temporarily formed, whereby the oil-solvent phase separates from the solid hydrocarbon phase or the hydrocarbon phase enters the auxiliary liquid phase.  The surface-active substance and the di-electric constants of the two liquid phases are such that the angle between the direction of the interfacial tension of the two liquid phases and the surface of the solid hydrocarbon phase under equilibrium conditions at a point where the three phases meet, is at least 90 degrees. Solvents referred to are dichloroethane, methylethyl ketone and benzene or toluene, methylethyl ketone, propane and benzene, and dichloromethane.  The auxiliary liquid is immiscible with the oil-solvent phase at the working temperature and has a higher di-electric constant; liquids referred to are water or the lower alcohols such as methanol and ethanol, glycol or glycerol mixed with water.  The pH of the auxiliary liquid phase may be adjusted by addition of aqueous NaOH.  Surface-active agents mentioned are preferably cation-active or anion-active substances; examples given are magnesium and sodium heptadecyl-9-sulphates, sodium C23-12-sulphate, alkylaryl sulphonates, dibutylnaphthyl sulphonate and di-isopropyl-naphthyl sulphonate, dioctylbenzyl sulphonate, polyethylene oxide substituted alkylaryl sulphonate, the sodium salt of dioctyl sulphosuccinic acid, the sodium salt of sulphonate oxyethylamine, alkyl-naphthalene sulphonate and castor oil, sulphonated ricinoleic acid ester, sodium dodecylbenzene sulphonate, sodium C9-13 benzene sulphonate, sodium sulphonates obtained in the refining of various mineral oils, sodium naphthenates, oleates and ricinoleates, the hydrochloric acid salts of octadecylamine and dodecylamine, and the substances known under the Trade Names "Breeze," "Triton K," "Lissolamine A," "Fixanol C," "Peregal OK," "Sulphaminol" and "Witol."  Salts, such as sodium chloride and calcium chloride or alcohols such as methanol or ethanol may be added to an aqueous auxiliary liquid when working at low temperatures to prevent freezing.  Demulsifiers may be added to ease the separation of the solid and liquid phases; examples given are various ammonium, lithium, sodium and potassium, magnesium, calcium, cadmium, zinc, copper, manganese, iron and nickel salts, and sodium sulphate together with cyclohexylamine, phenol, diphenylamine, amyl or dodecyl alcohols, cyclohexanol or substances known under the Trade Names "Lubrol," "Span," "Igepal," "Atlox," "Nonisol" and "Triton." Naphthenic acids and asphaltenes may be removed from the oil before treatment.  The oils treated may be liquid hydrocarbon mixtures such as waxy mineral oils such as kerosine and aromatic catalytically cracked oils; the process may be used to dewax oil, deoil wax, and to split paraffin wax into fractions of different melting points.  The dewaxing oil or deoiling wax processes may be carried out by filtering or centrifuging the paraffin wax from the oil-solvent phase and washing the oily wax with the auxiliary liquid; in this case the surface-active agent is added to the auxiliary liquid.  A number of other solvents, surface-active agents and demulsifiers are given in comparative examples outside the scope of the invention.  The words "Triton," "Lissolamine," "Fixanol," "Peregal," "Lubrol," "Span" and "Igepal" are Registered Trade Marks.