US1315623A - Process for the treatment of petroleum-oils - Google Patents

Description

E. B. COBB.

PROCESS FR THE TREATMENT 0F PETROLEUM OILS.

Arrucmou mm Auczz. Isn.

1,3 1 5 ,623. Patented Sept 9, 1919.

INYEIITOR WITNESS:

UNITED STATES PATENT OFFICE.

ERNEST B. COBB, 0F JERSEY CITY, NEW JERSEY, ASSIGNOR TO STANDARD OIL COMPANY, A CORPORATION OF NEW JERSEY.

Specification of Letters Patent.

Patented Sept. 9, 1919.

Application led August 2, 1917. Serial No. 184,072.

To all whom t may concern:

Bc it known that I, ERNEST B. COBB, a citizen of the United States, residing at Jersey City, in the county of Hudson and State of New Jersey, have `invented certain new and useful Improvements in Processes .for the Treatment of Petroleum-Oils, of which the following is a specification.

My invention relates to new and useful improvements in processes for the treatment of petroleum oils, and particularly contemplates a process for purifying and decolori'/,ing petroleum oils which have been subjected to treatment with sulfuric acid, for the purpose of removing from such oils reaction products such as sulfo-acids resulting from such acid treatment.

It is well known that petroleum oils have been treated with commercial sulfuric acid, c., of GGD Baume strength for the purposes of purification, and afterward either alkalinizing or neutralizing the oil so treated-with soda or other suitable neutralizer, for the purpose of removing the acid and reaction products. This treatment, however, is not satisfactory where extreme degrees of purity are desired, because the finished oil contained sulfo-acids which could not be 4removed by the well-known methods of treating with alkali.

My invention particularly contemplates i a process which will cffectually remove practically all of the sulfo-acid products which remain after the sulfuric acid and alkali treatment, and, therefore, make my improved process available fo-r producing oils which may be effectually treated to produce a product which is practically colorless and void of odor.

The invention consists in the improved process to be more fully described hereinafter and the novelty of which will be particularly pointed out and distinctly claimed.

In order that the various steps of the process will be readily understood by those skilled in the art, I have illustrated in the accompanying drawings one form of apparatus which may be employed with advantage to perform the process.

Before describing in detail the preferred method of carrying out the process, as regards the ingredients, quantities thereof, temperatures and steps employed, I would state the process briefly, as follows :l I'take a petroleum oil, such, for instance, as is to be employed for the production of an oil of a h1gh degree of purity employed for medicinal purposes, and treat the same with a proper amount of sulfuric acid for the purpose of removing the color, and those elements producing odor, employing for this purpose sulfuric acid of high strength-for instance, containing 20% of sulfuric anhydrid (S03) which is lOl-'Z; oleum--that is, it is an acid not only containing no excess free water but one which consists of the mono-hydrate with lthe sulfuric anhydrid in solution, and, therefore, of great strength, far beyond Athat hitherto usually employed in the acid treatment of petroleum oil. Other strengths of acid are not necessarily excluded if the character of the oil and the results desired permit.

This acid treatment may be repeated as often as may be desired in order to produce the required'degree of purification, the oil beingpermitted t0 cool between applications of the acid in order to prevent rapid evolution of gas-sulfurous acid gas due to the chemical reaction, which might result in destruction or alteration of the oils, the character of which it is desired to retain unchanged. After each application of the oil the resulting sludge is drawn off and the su ernatant oil is then subjected to the succee ing application of the acid if further application is necessary. When the desired number of applications of the acid have been made, the oil is permitted to stand so that the sludge may settle, which may requn'e anywhere from ten to forty-eight hours. The sludge is then drawn off and tlie'supernatant oil is transferred .to a clean vessel and alkalinized with soda-ash, sal-soda, or

caustic soda in solution, or any other ingredient suitable in oil treatment for neutralizing the acids-forexample, potash and ammonia. The action of the alkali is to neutralize the free acid and also the sulfoacids resulting from the reaction between the acid and the oil, and in certain types of oils, for instance, those from Texas crude, will neutralize the natural `acids therein. This alkali is added in an amount in excess of that required for neutralization, such as generally contemplated, and may be from 10 to 40 Baume solution in the case of caustic soda, for example. I employ alkali ofv great strength, and a large quantity thereof in order that the supernatant oil resulting after the alkali treatment will be practically emulsion-free, the alkali acting to render-the oil and the alkali solution as little soluble as possible in each other, and

therebyeffecting a distinct separation. After the alkali treatment the bottom layer containing the excess alkali, and the neutralized sulfuric acid in solution in the 'bulk of the Water are drawn off, leaving the upper layer of oily containing sulfo-acid salts in solution.

The usual method which would be followed at this point would be to wash the oils with water, but this cannot be done for the purpose of removing the sulfo-acid salts because the addition of the water'for washing would result in an emulsion being formed between the water and the sulfoacid salts which are-soluble partly in the water and partly in the oil, which would result in some of the sulfo-acid salts still remaining in the oil, and a permanent emulsion which it would be practically impossible to remove.

In order to effectually remove substantially all, if not all, of the sulfo-acid salts I` treat the oillcontaining these acid salts as follows:

The oil is treated by any suitable or well known step, for instance, blowing with air to remove water therefrom preferably as much as possible. When the alkali is withdrawn the oil may contain as much as '5% water, and I endeavor to remove as much of this water as possible. The oil is then subjected to glycerin .(C3H5(OII)3) which is y I thoroughly mixed therewith so as to effectually bring the glycerin in contact with all parts of the body of the oil, which glycerin forms a solution of the sulfo-acid salts, but

will not go into solution with the oil, except to a very small extent, if at all. This glycerin should be as water-free as possible. I have ascertained that commercial glycerin, which is 96% pure, will efectually obtain the desired results, but I do not limit myself to glycerin 'of this high degree of purity aS strengths as low as 90% have been found satisfactory, although strengths as low as 80% will not produce satisfactory results. After the glycerin treatment the treated oil is permitted to stand until it separates into ,viscosity at a temperature of 100 La ranas contain glycerin and the sulfo-acid salts in solution in glycerin, while the upper layer will be a hydrocarbon oil free from sulfo-.

acid salts. This oil may then be washed and filtered, whereupon it will be inodorous and practically colorless, and in which there will be no tendency to emulsify when submitted to the washing process. During the settling, after the glycerin treatment, the oil may be, and preferably is, maintained at a Suitable temperature, say about 170 ll., to hasten the settling process, which might take unnecessarily long, due to the viscous nature of the cold glycerin and the oil.

Having now described generally the process I will set forth in detail one example of performing the same, the same being described in shown in the accompanying drawing.

` The desired oil which has been previously treated with the sulfuric acid of great strength is flowed through a* pipe 1 into a covered tank or receptacle'Q. y As heretofore stated, the oil may be of any type which it is desired to purify, for example, an oil of 400 F. on the Saybolt universal viscosimeter, although I do not confine myself toI such an oil, as the process is of value in treatment of any viscous oil in which there is liability to the formation of emulsions when subjected to acid and alkali, for instance, an oil as low as 75 viscosity. In the previous treatment of the voil with sulfuric acid, the acidl of the connection with the apparatus in the oil when it comes 'from the still, as a -matter of economy in the use of acid.l The desired quantity of settled oil is run into the tank 2, and an alkali solution consisting of soda or sal-soda or other suitable alkaline Substance, as heretofore mentioned, but preferably caustic soda, `is run into the tank through an inlet pipe 3, this caustic soda solution being preferably from 10 about 10 Baume for purposes of economy, but the stronger the solution used the more certain will be the separation. It will be understood that the strength of the alkali solution and the quantity thereof employed must be such that there will be a clear line of separation between the oil and the bottom layer ,or aqueous layer. In employing a 10 strength of'caustic soda the volume would be about 20% of the body of oil being treated. As soon as a proper separation has taken place, which may take from ten to to 40 ABaume. I preferably employ a strength of forty-eight hours, but which will be readily apparent upon examination of the oils by sampling, the bottom layer containing the neutralized acid, water and the excess of alkali which has not entered into combination, is drawn off through a pipe 4 leading from the bottom of the tank and connected to the pipe 5, the pipe si containing a control valve 6, and the pipe 5 having a control valve 7. When the bottom layer has been drawn off', the upper layer of oil containing tracesl of water, which may amount to 5% by volume, and practically all of the sulfoacid salts resulting from the alkali treatment will remain in the tank, and the valves 6 and T are then closed. In order to remove the remaining traces of water which are in the body of oil, the latter is heated by a steam coil S in the bottom of the tank and controlled by inlet valve and outlet valve 10, to a temperature of 200O F., or there-about, this heating` serving to assist in the removal of water when the oil is subjected to blowing with air admitted to the interior of the tank by a blow pipe 11, the lower or outlet end of which tern'iinates adjacent the bottom of the tank so that the air will permeate the body of the oil. The top of the tank may be pro vided with an outlet vent 12 for the escape of steam and air. The heating and blowing is carried on until the escape from the vent pipe will cease to show water or steam, which can be determined by any of the well known means known by those skilled in the art.

The oil is then ready to be subjected to the glycerin, which is admitted to the interior of the tank 2 by an inlet pipe 13. This glycerin, as `heretofore stated, may be of con'nnercial strength, which is about 90%, the more water-free the glycerin is the better being the results obtained, although it may be 90%, as I have demonstrated. The glycerin is admitted to the tank in a quantity of about from to 10% by volume of the body of oil being treated. I have found that a quantity in proportion of 8% of glycerin by volumewill efficiently serve the purpose. The body of oil containing the glycerin is thoroughly agita-ted by any suitable means in order to thoroughly admix the glycerin with the oil and bringit in contact with all parts thereof. i A blast of air through the pipe 11, heretofore described, will efficiently produce the desired agitation. This step of treatment of the oil with the glycerin, accompanied by agitation, might take an hour, but this time is not obligatory because the purpose is to produce a solution of the sulfo-acid salts, and a definite separation, and the time for doing this, can be.

readily determined by test samples, that is, samples may be taken from time to time and the step terminated 'when it is clear that a definite separation takes place and the oil is free from sulfo-acid salts. When the treatment with glycerin is completed the body being treated is permitted to settle, which will result in the formation of two layers, the lower layer containing glycerin, sulfo-acid salts in solution in glycerin, and a comparatively small amount of oil, which may be soluble .in the glycerin ,mixture. This settling process may be accelerated by heating by the steam coil 8, and will take from twenty-four to forty-eight hours, although the time stated is not essential as it may be readily determined by test when a. proper separation has taken place. The upper layer produced from the settling will be the purified oil, free from sulfoarid salts.

Then the` settling and separation accomplished, the lower layer, heretofore described, is drawn off' from the tank 2, through the pipe .it and a pipe 1l, discharging into a still 15 for treatment for the purpose of recovering the glycerin for further usc. The pipe 1l is controlled by a valve 10. After the lower or bottom layer is drawn olf the purified'oil remains in the tank 2, and possibly small traces of' glycerin mechanically adhering to the interior of the tank. In order to remove these traces of glycerin the purified oil may be washed by flowing water, say 5% by volume of the oil, into the tank through the pipe 3 and agitat ing by the air blast, after which by sett-ling a bottom layer is formed containing the water and all the traces of glycerin not hitherto removed. This bottom layer may then be flowed through the pipes Je and 1liinto the still 15. The valve 16 may then vbe closed and the valves G and 7 opened,

and the purified oil run out of the tank 2, or a separate outlet for the purified oil may be provided if desired. This purified oil may be further treated by washing after withdrawal from the tank 2, and finally filtered through any decolorizer which is suitable, for instance, fullers earth or clay, whereupon the oil will be water-white, and in the oase of a medicinal oil, be made satisfactory for use.

The alkali mixture and glycerin which is flowed into the still 15 may then be heated by a suitable furnace 17, preferably` up to a temperature of about 4500 F., which will first serve to drive off the water, which will flow out of the dome 18 and through the pipe 19 to a coil 20 of a condenser 21, wherein the water will be condensed and flowed into one or the other of two rceeiving tanks 22, 23, connected respectively by inlet pipes 24, 25, with an outlet pipe :2G from the condenser coil, the pipes 24@ and 25 being provided with hand valves 27, 28, respectively, and each of the said tanks 22 and 23 may be provided tain some glycerin, Will 'liovv into the tankV 22, which is the first on the condenser out v let line. When the Water is driven ofi', glycerin and the sulo-acid salts will remain in the still, the said salts being non-volatile at temperatureV conditions and pressures at Which glycerin is volatile, preferably under vacuum produced by a vacuum pump 33 connected by a pipe 34 to the condenser outlet pipe 26, which resultsV in the glycerin being driven oil as a vapor iovving through the pipe 19 to the condenser coil, Where it is condensed, and from Which it emerges by the pipe 26 and passes to the receptacle 23. The distillation is carried on under vacuum or pressure as loW as possible to prevent decomposition of the glycerin. After the distillation has progressed until a small amount or trace thereof remains in the still,

this remaining amount may be recovered by accelerating the distillation by means of open-steam admitted to the interior of the still through a supply pipe 357 having at its lower end a perforated outlet pipe 36. 'lhe steam may be used, if desired, throughout the distillation to accelerate the distillation. The steam supply pipe 35 is provided With spaced hand valves 37, 38, between Which is a valved outlet pipe 39, 'Which latter may be employed as a Water drain to remove Water 'of condensation which might collect' in the steam supply pipe above the valve 38, so

that this Water Will not be permitted to pass y into thestill. The tanks 22 and 23 are connected by outlet connections 40, 41, With a pipe 42 leading to a liquid pump 43 having an outlet 4pipe 44 discharging into an open evaporator pan 45, the latter being heated in anyv suitable manner, as by closed steam coil 46, the inlet and outlet of 1which are controlled by hand valves 47, 48. 'lhe evaporator pan is'provided with a valved outlet 49 for removal, and each oithe connections 40` 41 is provided respectively With hand valves 50, 51.

After the distillation of the glycerin is completed the sulfo-acid salts remain in the still 15, from which they may be Withdrawn by an outlet pipe 52 controlled by an internal valve plug 53 operable by a valve stem 54 and handle 55, said outlet 52 also having an external valve 56. The condensed products which have passed over into the tanks 22 and 23 will consist oi a r mixture of Water and glycerin in the tank 22, and the glycerin of a higher degree of concentration 1n the tank '23. The products in the tanks 22 and 23, or either of them,

may be Withdrawn by the pump 43 and de-l livered into the evaporator pan 45,'vvhere, by heating by means of the steam coil 46, the

remesa stituting the bottom layer` alter the glycerin treatment, which is run into the still, Will be alkaline, and for this reason might result in decomposition of some of the glyc erin. ln order to obviate 'loss of glycerin, which might result from such decomposition, ll may add enough sulfuric acid to the mass in the still to make it neutral, and thereby prevent loss, which is likely to occur Were the strongly alkali mass alone subjected to the heat of the still.

By the term sullo-acid as employed `herein and in the claims, is meant those products or acids which result from the action of the sulfuric acid upon certain hydrocarbons or elements of hydrocarbons contained in petroleum oil. By the term sullo-acid salts as employed herein and in the claims is meant the neutralization products which result from the action of alkali on the sulfo-acids.

W hat l claim and desire to secure by Letters Patent of the United States is:

1- The process of treating petroleum oils containing sulfo-acid salts, Which consists in removing said salts from the oil by subjecting the oil to the action of glycerin.

2. The process of treating petroleumcils containing sullo-acid salts, which consists in removing said salts from the oil by subjecting the oil to the solvent action of glycerin.

3. vThe process of treating petroleum oils containing sulfo-acid salts, which consists in removing said salts from the oil by subje'cting the oil to the solvent action of glyc-- erin accompanied by agitation.

4. The process of treating petroleum oils 'containing sulfo-acid salts, which consists in removing said salts from the oil by subjecting the oil to thesolvent action of glycerin accompanied by agitationand heat. y

5. The process of treating petroleum oils containing sulfo-acid salts, which consists in removing said salts'from the oil by sub-` jecting the oil to the solvent action of glycerin under conditionspprecluding the presence of a substantial amount ofwater.

6. The process of treating petroleum oils containing sullo-acid salts, which consists in removing said salts from the oil by subjecting the oil to the solvent action of substantially Water-free glycerin.

7. The process xof treating petroleum oils containing sulfo-acid salts, which consists Ain removing said salts from thel oil by subjecting the oil to the solvent action of glycerin of over purity.

8. The processof treating petroleum oils containing sulo-acid salts, which consists in removing said salts from the oil by subjectiug the oil to the solvent action of glycerin of over 00% purity, accompanied by agitation and heat.

0. The process of treating oils which consists in subjecting the oil to the action of sulfuricl acid and an alkali, and removing the impurities` resulting from the acid and alkali treatment by subjectingl the oil to the action o'tA glycerin.

10. The process of treating oils, which consists in subjecting the oil to sulfuric acid and alkali of such strength and quan-V tity as to produce a clear line of separation between the oil and the aqueous layer upon settling, 'separating the oil from said aqueous layer, and removing the impurities resulting from the acid and alkali treatment by subjecting the oil to the solvent action of glycerin.

l1. The process of treating oils, which consists in subjecting the oil to sulfuric acid and alkali of such strength and quantity as to produce a clear line of separation between the oil and the aqueous layer upon settling, separating the oil from said aqueous layer, dehydrating the oil and removing the impurities resulting from the acid and alkali treatment by subjecting the oil to the solvent action of glycerin.

. l2. The process of treating oils, which consists in subject the oil to sulfuric acid and alkali of such strength and quantity as to produce a clear line'of separation between the oil and the aqueous layer upon settling, separating the oil :trom said aqueous layer, dehydrating the oil and removing the impurities resulting from the acid and alkali treatment by subjecting the oil to the solvent action of glycerin substantially tree from water.

13. The process of treating oils which consists in subjecting the oil to sulfuric acid and alkali of such strength and quantity as to produce a clear line of separation between the oil and the aqueous layer upon settling, separating the oil from said aqueous layer, dehydrating the oil and removing the impurities resulting from the acid and alkali treatment by subj ecting the oil to the solvent action of the glycerin, Washing the oil and filtering it. s

14. The process of treating petroleum oils containing sulfo-acid salts, which consists in subjecting the said oil to the solvent action of glycerin, settling out the glycerin and the solution of sulfo-acid salts in glycerin, and Washing and ltering the supernatant oil.

15. The process of treating petroleum oils containing sulfo-acid salts, which consists in subjecting the said oil to the solvent action ofglycerin, settling out the glycerin and the solution of sulfo-acid salts in glycerin and recovering the glycerin.

16. The process of treating petroleum oils containingr salto-acid salts, which consists in subjecting the said oil to the solvent action of glycerin, settling out the glycerin and the solution of suite-acid salts in glycerin and recovering the glycerin by distillation and evaporation.

17. The process ot' treating petroleum oils, which consists in subjecting the oil to strong sulfuric acid in proportion ot about 37% by volume of the oil treated. then treating the oil with alkali of from l0O to 40C Baumel in amount of about of the body ot oil being treated, thereby producing a clear line of separation between the oil and the aqueous layer upon settling. and removing the impurities resulting from the acid and alkali treatment by subjecting oil to the solvent action ot' glycerin.

18. The process of treating petroleum oils, which consists in subjecting the oil to strong sulfuric acid in proportion of about 37% by volume of the oil treated, then treating the oil with alkali of from 10C to 10o Baume in amount of about 20"( of the body of oil being treated, thereby producing a clear line of separation between the oil and the aqueous layer upon settling, and removing the impurities resulting from the acid and alkali treatment by subjecting the oil to glycerin in amount from 5% to 10% by volume of the body of oil.

19. The process of treating petroleum oils. which consists in subjecting the oil to strong suliuric acid in proportion of about 37% b v volume of the oil treated, then treating the -oil with alkali of from 10o to 400 Baume in amount ot' about 20% of the body of oil being treated, thereby producing a clear line of separation between the oil and the aqueous layer upon settling, separating the oil from said aqueous layer, dehydrating the separated oil and removing the impurities resulting from the acid and alkali treatment by subjecting the oil to the solvent action of glycerin.

20. The process of treating petroleum oils, which consists in subjecting the oil to strong sulfuric acid in proportion of about 37 by volume. ot' the oil treated, then treating the oil with alkali of from 10o to 40o Baume in amount ot' about 20% of the body of oil being treated. thereby producing a clear line ot' separation between the oil and the aqueous layer upon settling. separating the oil from said aqueous layer. dehydrating the separated oil and removing the impurities result- `ing from the acid and alkali treatment by subjecting the oil to the solvent'action of glycerin. which is practically Water-free and in amount o't` from about 5% to about 10% by volume of the body of oil.

21. Ihe process ot' treating petroleum oils, which consists in subjecting the oil to strong sulfuric acid in proportion of about 37% by Lemma Volume of the oil treated, then treating tbe giyoerinnvbieb is practically Water-free and voil Withealkaii of from 10 to 40 Baume in in amount of about 8% by volume of the amount of about 20% of the body of oil bebody of oil. ing treated, thereby producing a clear line in 'testimony whereof have hereunto 5 of separation between the oil and the aqueous Signed my name in the px'esenee of tWo subl5 layer upon settling, separating the oil from sciibing Witnesses.

said aqueous layer, dehydrating the sepa- ERNEST B. @@BB. rated oii and removing the impuities resuit- Witnesses: ing from the acid and alkali treatment by ROBERT Boxen,

10 subjecting the oil to the solvent action of THoMAs MITQHELL.

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