US1435824A - Refining liquid hydrocarbons - Google Patents

Description

A. E. DUNSTAN. REF |N|NG LIQUID HYDROCARBONS. APPLICATION FILED JUNE 2. 1919.

11.,4L35,82%, Patented Nov. M, 1922.

Inventor w. 2. Zia Attorney,

Patented Nov. Ml, 1922.;

warren srarss ALBERT ERNESTJDUNSTAN, 01E SUNBUBY, ENGLAND.

REFINING LIQUID HYDROCARBO'NS.

Application filed June 2,

T all whom it may concern Be it known that I, ALBERT ERNEST DUN- STAN, D. Sc, a subject of the Kin of Great Britain and Ireland, residing at fieadhurst, Cadbury Road, Sunbury-on-Thames, England, have invented certain new and useful Improvements Relatin to Refining Liquid Hydrocarbons, of whic the following is a I specification.

- sulfur are chiefly responsible.

This invention relates to a process of refining benzine, kerosene or other distillates from petroleum, shale oil and the like by the removal therefrom of the sulphur compounds such as organic sulphides, polysulphides and hydro-sulphides they may contain.

This invention particularly relates to the refining of oil for the removal of bad odors, to destroy any coloring matter originally present and to eliminate or prevent development of acid or corrosive products. So far as the causes of these objectionable pro-perties are known, organic compounds of The precise structure of all the sulfur compounds present in petroleum distillate and the like is not known, but I find that all the sulfur in these oils is amenable to treatment according to this invention. 7

According to the invention the liquid hydrocarbon is subjected to treatment with an alkaline solution of a hypochlorite, whereby the sulphur compounds contained in the liquid hydrocarbon are oxidized and bodies produced that readily pass into and are removed with the lye.

According to the invention, moreover, the treatment is effected in the presence of an excess of alkali. I

The invention comprises the features which are hereinafter described.

The invention is diagrammatically illustrated in the accompanylng drawing.

The invention may be carried into effect in any suitable form of electrolytic apparatus. For example an iron or steel vessel a of upstanding cylindrical form may be employed suitably earthed and carbon or graphite anodes cmay be used, and heat may be applied to the vessel in any suitable or convenient way. 'The liquid hydrocarbdn may be poured into the electrolyte and the electrolysis may proceed while the electrolyte is actively stirred by a stirrer 7). Heat may be applied to the vessel so that the treatment may take place at the optimum 1919. Serial N0. 301,359.

temperature. I have found a temperature of 120 F. efl'ective.

Any suitable hypochlorite may be used such as sodium hypochlorite with the addition of free alkali.

The presence of free alkali has'the effect of preventing corrosion of the vessel, of inhibiting chlorination of hydrocarbons, of stabilizing the hypochlorite and of assisting in the removal of the products of the treatment which result mainly from the oxidation of the organic sulphur compounds originally present in the liquid hydrocarbon treated.

The alkaline solution of a hypochlorite may be produced in an apparatus external to the mixer in which the operation proceeds. In fact, the solution may be prepared by any of the known methods, such as electrolysis of a salt solution in special cells for the production of hypochlorite, by passing liquid chlorine into a solution of an alkali such as caustic soda or milk of lime, or by dissolving bleaching powder in sufficient water to produce a solution of-the proper hypochlorite content and alkalinity.

s has been pointed out above the presence of freealkali renders the solution free from uncombined chlorine, and inhibits the chlorination of the hydrocarbon. Liquid hydrocarbons refined according to this invention are chlorine free for all practical purposes.

The oil to be treated should be analyzed so as to discover its sulphur content. For each unit amount of sulphur there should be provided at least one unit amount of oxygen resulting from the decomposition of hypochlorite. The amount of free alkali should at least be of the order of 0.1 per cent concentration. Th concentration of the hypochlorite should be at least 0.25 normal. The current density in the electrodes may be from .15 to .40 amperes per square centimeter. The' duration of treatment should be determined by test with each individual oil.

In cases where the oxidized sulphur compounds are of high molecular weight and are relatively insoluble in'alkali, they may be removed from'solution in the refined oil by means of filtration through animal charcoal, dehydrated alumina, fullers earth or any suitable decolorizing agent.

Before treating hydrocarbons containing hydro-sulphides or mercaptans,,the hydrocarbon may be first treated with caustic soda so that it may be substantially deprived of these bodies before treatment according to the invention and thus the hypochlorite economized.

Iclaim:" '1. A process for refining liquid hydrocarbons containing sulfur compounds, comprising subjecting said hydrocarbons to treatment with a solution comprising a hypochlorite in concentration at least 0.25 normal and free alkali in concentration at least 0.1 per cent.

2. A process for refining liquid h drocarbons containing sulfur compoun s, comprising subjecting said hydrocarbons to treatment with a solution consisting of a hypochlorite and free alkali without introducin chlorine into the liquid hydrocarbons.

3. 1% process for refining liqmd hydrocarbons containing sulfur compounds, comprising subjecting said hydrocarbons to treatment with an alkaline solution of a hypochlorite in proportion to provide about one unit of oxygen from decomposition of the hypochlorite .to each unit of sulfur in the liquid hydrocarbom I ALBERT ERNEST DUNSTAN.

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