Patent GB-494450-A (GB)
Title: A process for removing acid components from hydrocarbons or derivatives thereof
IPC: C10G19/04
Filed: 1937-09-28
Abstract: Hydrocarbons or derivatives thereof are freed from weakly acid-reacting organic substances by extraction with an aqueous alkaline solution in the presence of an auxiliary agent consisting of aliphatic polar compound containing at least 2 alcoholic hydroxy radicals and with or without a carbon chain having at least 2 oxygen atoms attached to separate carbon atoms, in which the ratio of carbon atoms to hydroxy radicals is not less than 1 1/2 , the ratio of carbon atoms to polar radicals (including hydroxy radicals) is not more than 2 1/2 , and the carbon atoms exceeds the polar radicals by not less than one. Auxiliary agents specified are, propylene, butylene, or isobutylene glycols; 1,3 to 1,4 dihydroxy butane, alkyl glycerines, diethylene glycol, triethylene glycol glycerine monoethyl ether, or 1.2.3.aminodehydroxy butane.  Alkaline substances used are, alkali metal or alkaline earth hydroxides, quaternary ammonium bases, alkali carbonates or bicarbonates. Aqueous alkali solutions of from 3 to 6 N concentration containing from 15 to 85 per cent of auxiliary agent are used.  Liquids treated are petroleum, benzene, toluene, zylene, chlorinated hydrocarbons such as chlorethane, ethylene dichloride, trichlorethylene, carbon tetrachloride, chlorpropane, chlorbutylene, chlorbenzene; brombenzene; nitro-hydrocarbons such as nitroethane, nitrobenzene; or amines such as amylamine, aniline, pyridine or petroleum bases.  The organic acid-reacting substances removed are mercaptans, phenols, naphthenic acids and fatty acids. Extraction may be effected by a batch or a countercurrent method in a tower or in a series of mixers and settlers.  The treated liquid is then washed with water to remove any auxiliary agent.  In the desulphurizing of petroleum, the treated petroleum may be further purified by treating with "Doctor solution," hypochlorite, or by oxidation with air in the presence of catalysts such as copper compounds, lead sulphide or nickel sulphide, if desired in the presence of alkali.  The spent alkali solution and washings are regenerated and the auxiliary agent is recovered by steaming, solvent extraction or distillation under reduced pressure.  If the spent alkali solution contains mercaptans only, these may be removed by oxidation with air to form disulphides and the latter removed by settling, extraction, or steaming.ALSO:Hydrocarbons or derivatives thereof are freed from weakly acid-reacting organic substances by extraction with an aqueous alkali solution in the presence of an auxiliary liquid consisting of an aliphatic polar compound containing at least 2 alcoholic hydroxy radicals, and with or without a carbon chain having at least 2 oxygen atoms attached to separate carbon atoms, in which the ratio of carbon atoms to hydroxy radicals is not less than 1 1/2 , the ratio of carbon atoms to polar radicals (including the hydroxy radicals) is not more than 2 1/2 , and the carbon atoms exceeds the polar radicals by not less than 1. Auxiliary agents specified are, propylene, butylene, or isobutylene glycols; 1,3 or 1,4 dihydroxy butane, alkyl glycerines, diethylene glycol, triethylene glycol, glycerine mono-ethyl ether, or 1,2,3,amino-dihydroxy butane.  Alkaline substances used are, alkali metal or alkaline earth hydroxides, quaternary ammonium bases, alkali carbonates or bicarbonates.  Aqueous alkali solutions of from 3 to 6N concentration containing from 15 to 85 per cent of auxiliary agent are used.  Liquids treated are, benzene, toluene, xylene; chlorinated hydrocarbons such as chlorethane, ethylene dichloride, trichlorethylene, carbon tetrachloride, chlorpropane, chlorbutylene, chlorbenzene; brombenzene; nitro-hydrocarbons such as nitroethane or nitrobenzene; or amines such as amylamine, aniline, pyridine or petroleum bases.  The organic acid-reacting substances removed are mercaptans, phenols, naphthenic acids and fatty acids.  Extraction may be effected by a batch or countercurrent extraction method in a tower or in a series of mixers and settlers.  The treated liquid is then washed with water to remove any auxiliary liquid.  The spent alkali solution and washings are regenerated and the auxiliary liquid is recovered by steaming, extraction, or by distillation under reduced pressure.