US1988084A - Refining of hydrocarbon oils - Google Patents

Description

Jan.415, 1935. 1 C. MORRELL 1,988,084

REFINING OF1 HYDROCARBON OILS Fiied May 31, 195o Patented Jan. 15, 1935 A u l UNITED STATES PATENToI-FTCE aEFnmrG or maooAaBoN orLs Jacque C. Morrell, Chicago, Ill., assigner to Universal Oil Products Company, Chicago, Ill., a corporation oi' South Dakota `Application May 31, 1930, Serial No. 458,718 v Claims. (Cl. 196-36) This invention relates to the treatment of as well as for the particular reiining purpose in hydrocarbon oils, and refers more particularly hand. to the treatment of cracked hydrocarbon oils In the use of water as a solvent, some hydrolresulting from the conversion of higher boiling ysis occurs in which case I prefer to add a small 5 hydrocarbons at elevated temperatures and usuamount of acid to the solution which for con- 5 ally under pressure .into lower boiling hydroI venience may correspond to the acid radical of carbons suitable for motor fuels. the salt. For example, in the case of the sul- The process of the vinvention may be directed phates, sulphuric acid may be used; in case ofl specifically to the rening of cracked hydrothe acetates, acetic acid may be used, and in l0 carbon oils for the production of marketable the case of the chlorides, hydrochloric acid may lo motor fuels. Cracked hydrocarbon oils contain be used, but I do not limit myself to this provarious groups of hydrocarbons including arocedure. matic, naphthene, parailin and unsaturated hy In a specific embodiment of my invention, I drocarbons. The unsaturated hydrocarbons introduce the acid into the solution. of the heavy may consist not only of the mono-oleflnes, but metal salt, preferably the acid corresponding to l5 also of the more highly unsaturated oleilnic the negative radical of the metal salt. The purcompounds such as the diolenes. The highly pose of introducing the acid is several-fold, unsaturated compounds tend to polymerize, namely to prevent hydrolysis of the heavy metal forming heavy tar-like material which action as salt or repress the hydrolytic action, to assist in well as others forming similar compounds is the refining action by the treatment of the hy- 2o promoted by the effect of light and heat. drocarbon vapors with the acidic solution itself Stored gasolines also show this tendency. and to prevent formation in many cases of the Increase in gum in a stored motor fuel causes metal sulphide which would tend to exhaust the difllculties in the operation of the motor by treating solution. 'I'he concentration of the gumming up of. the feed lines and the intake acid depends upon the results desired, and I 25 and exhaust valves. have obtained good results with concentrations In addition to the formation oi the gummy varying from a fraction of a per cent to l0 per'v material some cracked gasolines exhibit a tencent, more 0r less, for the prevention of hydrolydency to deteriorate with respect to anti-knock sis and concentrations varying from several per I qualities, thus reducing their value as a motor cent to 50 per cent or less to assist in the re- 30 fuel. l ning action. It is apparent that my invention It is among the purposes of my invention to contemplates not only the use of' heavy metal avoid these difficulties and vat the same time to Salts With 9 Small Percentage 0f acid fOr the produce marketable gasolines with respect to PUIDOSGS before mentioned, but also the use 0f color, odor and stability. mixtures ci heavy metal salts and acid infsolu- 35 In the operation of the process of my inventi011- tion, I make use of heavy metal salts such as The solutions of the heavy metal salts serve asv the nitrates, sulphates, acetates and other salts refining agents' Presumably by polymerization'. of non, aluminum antimony, bismuthcadmmm, and in general conversion of the undesirable 40 chromium zinc, tm copper, titanium, and in separation of the undesirable color and gum 40 general the metallic salts of various acids, some formmg compounds may occur Immediately of.which wm be illustrated by the examples upon treatment or may be latereiected. shown. These salts are dissolved in a solvent The treatment may be applied m one or sev' eral ways. For example, I may distill the oil which may be water or organic solvents alone or in combi non. I. examples of the organic `over the solution o1' the heavy metal salt or the 45 vapors of the oil undergoing treatment may be solvents' I may mefmon alcohols such as passed counter-current to the solution, or the methyl ethyl Propyl' lso'propyl butyl isobutyl' vapors of the hydrocarbon oil undergoing treatamyl iso'amyl and the hke- I may also make ment may-be contacted with a solution of the 5o use 0f the Polyhydlc alcOhUlS Such as glycolsf heavy metal salt in a suitablevessel or con- 50 glyCeIIle and the like. other liqllld derivatives tainer, In all vcases the vapors ls() treated are which dissolve any 0I the heavy metal Salts may condensed and recovered. Make-up solvent may be used. Itis to be understood that the solvents be added from time to time as some of the or mixtures of solvents are chosen with respect solvent is lost by evaporation. The heavy metal 55 to the heavy metal; salt or salts to be diolved salts may be recovered or reconverted when 55 changed by chemical reaction using suitable and well-known methods. The treatment may be the sole treating step or may be used in combination with other treatments; for example, in the case of the vapors, they may be subsequently scrubbed and otherwise treated by passage through a vessel containing an adsorbent material such as fullers earth, bone black and the like, or with mixtures of these materials with alkalies such as lime, caustic soda, etc. Metallic oxides may also be used either alone or in combination with the adsorbent earths and/or alkalies. In the case where the vapors are contacted with the solution of the heavy metal salt either by passing the solution counter-current thereto or by passing the hydrocarbon vapors through a solution oi the heavy metal salt or otherwise contacting the hydrocarbon vapors with a solution ot heavy metal salt, I prefer to fractionate the vapors to the desired end point before such treatment, and preferably the vapors are subsequently subjected to a fractionating or scrubbing action either by passing through a dephlegmator or fractionating column or element containing baille plates for the purpose of removing suspended or entrained tar-like or polymerized products. Ammonia or other alkaline material may be injected into the condenser to prevent corrosion. I may also treat the hydrocarbon oils by contacting with the solutions of the heavy metal salts and removing the sludge or other reaction products therefrom. Where the solutions are contacted directly with the oil to be treated, it is preferable to be used in combination with other refining steps in suitable order such as by alkali washing acid treatment, treatment with earthy material, metallic oxides, dry alkalies, etc.

The process may be usf-x1 in direct connection with a cracking unit or in connection with an ordinary distillation unit so that the vapors either from the primary cracking process or from the redistillation of the primary light product of the cracking process may be treated in the manner described. When connected directly to a cracking unit, I prefer to scrub the gases with a reagent or material to remove hydra-gen sulphide such as lime, caustic soda and, in general, alkalies, oxides of metal, etc.

The process may also be adapted to the treatment in the usual manner as described, i. e., by contacting the heavy oil with the solution or the heavy metal salt, removing the sludge and preferably treating with an alkali and subsequently water washing the distillate.

The distillate to be treated, supplied through line 1 and valve 2, is pumped through pump 1', line 2', and may be passed through valve 5 directly to heating coil 3 located in furnace setting 4. The distillate leaves the heating coil controlled by control valve 6 in line 8' and enters evaporator 7. Steam may be introduced through line 8, controlled by valve 9, to assist the vaporization. Unvaporized residue may be withdrawn through line 10, controlled by valve 11. The vapors leaving evaporator 7 pass through line 12, controlled by valve 13, into fractionating tower 14. Steam may be introduced through line 15, controlled byvalve 16, to reboil the redux formed in the tower 14. The unvaporized residue may be parsed through line 17, controlled by valve 18, to storage, or it may be returned after reboiling into the heating coil 3 through line 19, valve 19', pump 20, lines 21, 21', valve 22 and line 2', or the reflux may be passed through line 21, controlled by valve 22, through a separate heating coil 23, passing into evaporator 7 through line 24, controlled by valve 24.

The raw charge may also enter the fractionating column 14 through line 25, controlled by valve 26, the reflux being treated as heretofore described.

The vapors leaving fractionating column 14 through line 27' and valve 28' enter the treater 27, preferably through a perforated rose or similar arrangement 28. Various gases may be introduced into vapor line 27' through line 33' and valve 34' and thence into the treater 27, e. g., hydrogen, oxygenor gases containing these. The oxidizing and reducing gases are introduced separately. Finely divided metals may also be added, especially if the solution is made acid by further addition of acid. The treating solution, consisting of the metal salt and a solvent, is placed in treater 27 using a suflicient amount to permit thorough treatment of the vapors which bubble up therethrough and contact with the treating liquid. In order to make up for the loss of solvent due to evaporation, additional solvent supplied through line 29 and valve 30 is fed by means of pump 29 through line 30, controlled by valve 31. Line 32, controlled by valve 32', permits the withdrawal of the solvent or other liquids accumulating in treater 27. Drawoi lines 33, controlled by valves 34, permit removal of liquid and adjustment of levels. The treated hydrocarbon vapors leaving treater 27 pass through line 35, controlled by valve 36, into the secondary fractionating column or scrubber 37. Ammonia may be introduced through line 38, controlled by valve 38', to neutralize acid vapors passing from the treater. Likewise, an alkaline solution, such as sodium carbonate or sodium hydroxide, may be fed through line 39, controlled by valve 39. Steam may be introduced. through line 40, controlled by valve 40', to assist in vaporization.

The bottoms accumulating in tower 37 may be withdrawn through line 41, controlled by valve 41'. The vapors leaving tower or scrubber 37 pass through line 42, controlled by valve 42', into cooler and condenser 43. The condensed liquid is collected in receiver 44. Control valve 45 permits additional control of the pressure. The liquid is removed from receiver 44 through line 46, controlled by valve 46'. Gases and vapors' accumulating in receiver 44 are removed through line 47, controlled by valve 47'. A portion of the liquid in receiver 44 may be withdrawn 55 through line 48 and valve 49 and returned by means of pump 48' to tower 37 through line 49' and valve 50, or to tower 14 through line 49', valve 51 and line 52. Any other suitable cooling fluid or refluxing may also be introduced through line 52 and valve 52' into tower 14.

It is to be understood that this is only one of the many forms of apparatus in which the process of my invention may be carried out; for example, a shell still may be substituted for the pipe coil heated as shown, and in either case a vessel containing dry neutralizing agents, such as lime or caustic soda, alone or in combination with earthy adsorbents, metallic oxides, etc., may be used following the treater 27. The treater may also be connected directly to a cracking unit, in which case I preferably make use of neutralizing agents or other means toremove hydrogen sulphide before passing the vapors to the treater.

As an example of the operation of the process oi' my invention, a cracked distillate from a 17 gravity California fuel oil was vaporized, and the vapors subjected to fractionation and thereafter treated in the manner described with a solution of zinc chloride containing 10 per cent hydrochloric acid. The vapors leaving the treater were passed through a column containing a mixture of adsorbent earths (fullers earth) and lime, the purpose of the latter being to neutralize the hydrochloric acid. Ammonia was introduced in the column to assist in the neutralization. It was found that an improvement was obtained in the reiining action upon the distillate, owing to the presence of the acid and that further, the formation of zinc chloride was prevented owing to the repression of the sulphide ion concentration by the presence of a high concentration of hydrogen lon due to the hydrochloric acid. The hydrogen sulphide so formed reacted in part with the lime or'ammonia. The solution required less reviviilcation and treatment for the removal of the suspended sulphide, both with the use of zinc chloride and the use of other heavy metal salts solutions. Other acids produced similar effects. 'Ihe product produced by this process was sweet in odor, water white in color, and stable.

I may use the other heavy metal salts, such as ferric chloride, zinc sulphate, ferrie sulphate, zinc acetate and the like to obtain similar results with varying concentrations of acid. Various concentrations ofthe salt were used depending upon the. amount of reilning required, the temperature and other conditions.

It is to be understood that owing to the broad scope of my invention, there are many possible solutions or combinations of solutions of heavy metal salts and solvents as well as combinations in treating steps andl methods of application of the process, and in view of this, the examples and illustrations given are not to be construed as limitations thereon.

I claim as my invention:

1. A process for refining cracked gasoline which comprises contacting the same in vapor form with an aqueous solution of a zinc salt containing an acid which prevents hydrolysis of the salt, and then condensing the thus treated vapor.

2. A process for refining condensible 'hydrocarbons which comprises contacting the same in vapor form with an aqueous solution of a zinc salt containing an acid which corresponds to the acid radical of the salt, and then condensing the thus treated vapor.

3. A process for reilning condensible hydrocarbons which comprises contacting the same in vapor form with' a solution of a zinc salt containing an acid capable of and in amount sufficient to prevent the conversion of the salt into a metal sulphide and subsequently condensing the treated vapors.

4. A process for refining hydrocarbon oils which comprises treating the same in vapor form with an aqueous solution of a heavy metal saltcontaining an acid corresponding to'the acid radical of the salt, said acid being capable of and in amount suillcient to prevent hydrolysis of the salt, thereafter fractionating the vapors in the presence of alkaline material to 'remove polymerization products formed by the treatment and to neutralize lsaid vapors carried over from the solution, and then condensing the fractionated and neutralized vapors.

5. In the refining of hydrocarbon oilil,` the step which comprises treating the oil in vapor form 'with an aqueous solution of a heavy metal salt containing an acid corresponding to the acid radical of the salt, said acid being capable of and in amount sumcient to prevent hydrolysis of the Salt.

JACQUE C. MORREIL.

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