US2396673A - Petroleum mahogany sulphonic products - Google Patents

Description

Patented Mar. 19, 1946 PETROLEUM MAHOGANY SULPHONIC PRODUCTS Manuel Blumer, Petrolia, Pa, asslgnor to L.

Sonneborn Sons, Inc., New York, N. 1., a corporation of Delaware No Drawing. Application October 19, 1943,

Serial No. 508,896 7 13 Claims.

This invention relates to new and useful improvements in petroleum mahogany sulphonic products.

In the acid refining of petroleum hydrocarbons under sulphonating conditions, there are recovered in the oil layer after acid treatment, certain sulphonic acids generally referred to as mahogany petroleum sulphonic acids by reason of the color which they impart to the oil layer in which they occur. These mahogany petroleum sulphonic acids originally constituted limitedly valued by-products, particularly of white oil refining. However, these products have since become valuable as additives, detergents, emulsifying agents, etc.; in fact they are, valuable to such an extent today, that their production is often the prime purpose of petroleum hydrocarbon sulphonation treatments.

In accordance with hitherto known methods of procuring petroleum mahogany sulphonic products, including both the free acids, as well as their salts, only relatively poor yields were obtained and in all commercially practicable operations the products obtained were contaminated by colored or color-inducing substances, primarily resulting from the presence of polymers, tarry and the like products.

Attempts to increase the of appreciable after-treatment or refining and to obtain in many cases yields of a magnitude hitherto not commercially obtainable.

The process in accordance with my invention essentially and broadly comprises the thorough mixing of an acidified oil and preferably a nonsettled oil as it results from the acid treatment of a petroleum hydrocarbon stock under conventional' sulphonating conditionswith a suitable organic solvent to thereby obtain a top layer essentially comprising mahogany sulphonic acids, solvent and oil and thereafter recovering mahogany sulphonic acids or their salts preferably in oil solution from the solvent layer. 7

Within the preferred embodiment of my in vention and to obtain maximum yields, I find it of advantage to modify the conventional acid treatment of a petroleum hydrocarbon oil stock to be used in the procedure in accordance with my invention. Accordingly, I pretreat a petroleum hydrocarbon stock with relatively small amounts and preferably not appreciably in excess of by weight of fuming or concentrated sulphuric acid and preferably with a concentrated sulphuric 1 acid of about 66 B. at sulphonating tempera- 1 ture for the oil which is best selected between 125518, and 175 F. and preferably at 150 F. and

yield of mahogany sulphonic products by increasing the amount of concentration of acid to thereby obtain a boosted sulphonation reaction are usually accompanied by a deterioration of the color due to the increased formation of these objectionable sulphonation by-products responsible for the dark color of the resultant products. By reason of the fact that many of the uses to which petroleum mahogany sulphonic products are put, such as for instance in textile treating thereafter follow this acid pretreatment by the addition of S03 preferably introduced by way of fuming sulphuric acid and preferably oleum of oils and various emulsification uses, it is necessary that the products be as light in color as possible so as not to impart an objectionable tint or coloration to the materials with which they come into contact in the course of a particular treatment. As a result of the necessity for substantial freedom from objectionable discoloration of petroleum mahogany sulphonic products, it has therefore been necessary in the past to resort to cumbersome, uneconomical, costly and time consuming operations and devices, to bring these productsto the state of desired refinement, i. e. relatively low color value. i 7

I I have discovered a new method in accordance with which it is possible to obtain petroleum sulphonic acid products-substantially free fromall objectionable discoloration or discoloring matters about 20% S03 content at a temperature of between F. and 160 F. and preferably between F. and 1409f". Addition of S03 as such as well as addition of SO: by way of fuming sulphuric acid having an S03 content appreciably in excess of 20% produces more heavily viscous sludges presenting well known operational dimculties. For best results it is advisable to permit settling of acid sludge after'the pretreatment preferably at a temperature of between and F. and to remove the sludge layer prior to the subsequent S0: or fuming sulphuric acid treatment.

The resulting reaction mix containing both acidified oil as well as acid sludge is then thor-j oughly mixed with the solvent as for instance V benzol, preferably in a volume ratio of solvent to and for best results of total reaction mix of 0.3 T to uln Whereas approximately the volume ratio gives normally the highest yields,

asfor instance a volume ratio of 7 does not ordinarily produce yields materiall higher than obtained by the use of the volume ratio.

The solvent treatment as such, does not normally require critical temperature conditions. It is preferred however to so adjust the temperature that the mix after agitation may be left to settle and stratify at a temperature between 125 F. and 140 F. In the practical operation of my invention therefore, it is normally advisable to add the solvent to the acidified mix immediately after the oleum treatment and while the same is still at about the sulphonation employed. In such case, if the addition of the solvent results in a material lowering of the temperature, it may be of advantage to raise the temperature of the mix to between 125 F. and 140 F. for best stratification results.

The resulting toplayer of the mix essentially contains unreacted oil, petroleum mahogany sulphonic acids and solvent, whereas the bottom layer is essentially an acid sludge layer containing unreacted acid, tarry materials and petroleum green sulphonic acids, which latter are essentially water-soluble and oil-insoluble. The petroleum mahogany sulphonic acids may then be recovered as such but preferably in the form of the alkali salts from the solvent layer. It is preferred, however, to neutralize the acidity of the solvent layer by a suitable caustic, as for instance a 25 Be. sodium caustic soda solution and preferably to the phenolphthaleine end point, whereupon stratification occurs, leaving an upper substantially neutral solvent layer and an aqueous layer of spent caustic solution. The latter layer is withdrawn and the solvent layer is preferably first washed for removal of salts and then worked up by removing the solvent, such as by distillation, to leave mahogany sulphonates in solution in oil. If for any reason it should be desired to recover the sulphonates from this oil solution, this may be done. In solvent cases, the oil solution is dehydrated to remove final traces of water and then used as such, asin the macolorless, and measured in color values possess less than 13 and usually between. 0.25 and 051?. (Lovibond cell).

Within the scope of my invention the petroleum hydrocarbon oil that-I prefer to use'as a starting material is a straight overhead distillate preferably from a Texas or Gulf Coast crude and specifically a non-solvent refined stock having a Saybolt viscosity of 150 seconds or higher at 100 F. L

Satisfactory solvents in accordance with this invention are benzol and its normally liquid homologues, normally liquid chlorinated benzol or benzol homologues and normally liquid saturated chlorinated aliphatic hydrocarbons. Specific solvents of this type and nature are for instance benzol, chlorbenzol, carbon tetrachloride and ethylene dichloride. In the majority of cases benzol constitutes the preferre solvent.

When proceeding within the preferred embodiment of my invention I prefer to use from 60 to 100% total acids, i. e. both concentrated sulphuric acid and oleum by weight calculated on the total weight of the hydrocarbon stock to be sulphonated. For best results I find it of advantage to use for the pretreatment from 15 to 50% and preferably 15% concentrated sui- I Example I 1000 parts by weight of a Gulf Texas 500" viscosity (Saybolt at 100 F.) oil is treated with jority of cases it is desirable to use oil as a carrier parts by weight of. 66 B. sulphuric acid at F. The acid is relatively slowly stirred in with thorough agitation. After addition of the acid the mix is permitted to stratify and the acid sludge formed settles. During stratification the temperature is maintained at 150 F. Upon completed stratification the acid sludge is withdrawn. Thereafter 500 parts by weight of oleum are agitated into the oil at 150 F. followed by the addition of benzol in volume substantially equal to the volume of acidified mix. The entire mix is permitted to stratify and the bottom layer of acid sludge is withdrawn and the upper benzol acidified oil laveris neutralized with 27 B. caustic soda to phenolphthaleine end point. The neutralized mix is allowed to settle and the spent caustic layer is withdrawn. The upper layer is then transferred to a still and the benzol distilled off. The mahogany sulphonate in' oil solution is then dehydrated and withdrawn.

Example II 1000 parts by weight of a Gulf Texas 750" viscosity (Saybolt at 100 F.)' oil is treated with 100 parts by weight of 66 B. sulphuric acid at about 150 F. with vigorous stirring, whereupon after addition of the acid the sludge formed is permitted to settle while maintaining the tem' perature at 150 F. The sludge is thereafter removed and the remaining oil layer is treated with 15% by weight of pure anhydrous s Eat 150 F. -'I'he S0: is added preferably. ;diluted with air to a concentration of about Tto' 10%of $02. The air S0: mixture is induced into the oil by means of any conventional gas dispersing means.

After completion of the addition of the $0: a volume of benzol equal to the volume of total After the addition of settled a pletely stable emulsi Y limited by acidified mix is added with vigorous s the benzol is completed, to stratify and worked up recovery of mahogany petroleum sulas described in connection with Exthe mix-is permitted for the phonate ample I.

In lieu of the benzol specified in .the above Examples I and 11 any other of the solvents useful in accordance with the invention; such as carbon tetrachloride, diethylene dichloride. chlorbenzol or the like may be used, all other treating conditions and steps remaining the same.

Within the broad purview of my invention an acidified oil layer as, for instance, conventional obtained in sulphuric acid refining, may be used. This acidified oil layer may be subjected to the solvent treatment in accordance with the inven tion, with or without prior removal of acid sludge. It is, however, preferred to take a noncid treated oil, i. e. an oil containing comparatively large amounts of acid sludge, therein dispersed. In many instances I find it advisable when using an acid treated oil that has settled, to again disperse therein by suitable agitation the acid sludge stratified therefrom.

When resorting to the pretreatment in accordance with the preferred embodiment of my invention, I find it of advantage as hereinabove related, to remove for best results the acid sludge formed after the pretreatment. This removal state, however, though permitting the obtaining of superior results is not crltical'to the principle of the invention and if desired may be omitted should such omission be desirable for operational or other reasons.

The products obtained in accordance with the invention as above pointed out are substantially free from objectionable discoloring matters, i. e. polymers, tarry and sludge materials, and substantially possessed of Lovibond colors of values less than IR and usually between 0.25 and 0.51% 1/2' Lovibond cell, they are spontaneously emulsifiable in water and form substantially comons, especially upon the addition of minor amounts such as l to 2% of water and a suitable linking agent such as diethylene glycol in similar concentration. g

The hydrocarbon oil solutions of the petroleum mahogany sulphonates obtained in accordance with the invention normally contain from 70 v to 80% and usually 75% of hydrocarbon oil and are substantially free from salts and other inorganic matter.

The foregoing description is furnished by way of illustration and not of limitation, and it is,

therefore, my intention that the invention be the appended claims only or their wherein I have attempted to claim inherent novelty.

equivalents broadly all I claim: 1. Method for the production of petroleum mahogany sulphonic products which comprises treatv ing'a non-settled acidified petroleum hydrocarbon oil containing petroleum mahogany sulphonic acids, acid sludge and unreacted oil, derived from the sulphuric acid treatment of a straight overhead distillate, having a Salbolt viscosity at 100 F. of at least 150 seconds, under sulphonating conditions of acid amount and temperature, with an organic normally liquidsolvent selected from the group consisting of normally liquid benzol, benzol homologues, chlorbenzol, chlorinated benzol homologues and saturated chlorinated aliphatic hydrocarbons, permitting the reaction mix to leum hydrocarbon oil sol hogany sulphonic acid layer predominantly ogany sulphonic acids settle to thereby obtain a top containing petroleum mah and oil in solution in said solvent, and thereafter recovering from said layer a petroleum sulphonic product of high purity substantially free from discoloring materials.

2. Method in accordance with claim 1 in which said solvent is benzohand in which said acidified oil is substantially non-settled.

3. Method in accordance with claim 1' in which said solvent is present in vent to acidified oil from 0.3 1 v T r volume ratio of solin which said top layeris neutralized and permitted to settle, to thereby form a second top layer predominantly containing petroleum mahogany sulphonate and oil in solution in said solvent, and in which said second top layer is thereafter treated to recover therefrom a petroution of petroleum mahogany sulphonates of high purity and substantially free from discoloring materials.

4. Method for the production of petroleum mahogany sulphonic products which comprises treating a petroleum hydrocarbon stock of the straight overhead distillate type, having a Saybolt viscosity at F. of at least seconds, with concentrated sulphuric acid under sulphonating conditions of acid amount and temperature, thereafter treat-= ing'the resulting stock with $03 under sulphonating conditions of acid amount'and temperature, thereafter agitating the lastly resulting mix containing petroleum mahogany siilphonic acids, acid sludge and unreacted normally liquid solvent selected from the group consisting of normally liquid benzol, benzol homologues, chlorbenzol, chlorinated benzol homologues and saturated chlorinated aliphatic hydrocarbons, permitting the solvent treated mix to settle to thereby obtain a top layer predominantly containing a solventsolution of petroleum mabon stock and thereafter'recovering from said layer a. petroleum mahogany sulphonate petroleum hydrocarbon solution of high purity and substantially free from discoloring materials.

5. Method for the production of petroleum mahogany sulphonic products which comprises treating a petroleum hydrocarbon stock of the straight overhead distillate type, having a Saybolt viscosity at 100 F. of at least 150 seconds, with a relatively small amount of concentrated sulphuric acid at a temperature between 125 and 175 F. to thereby form acid sludge, removing said acid sludge, treating the resulting stock at a temperature between 80 and. F. with fuming sulphuric acid to thereby form further amounts of acid sludge, agitating the resulting mix containing petroleum mahogany sulphonic acids, acid sludge and unreacted oil including acid sludge with an organic normally liquid solvent selected from the group consisting of norm zol, benzol homologues, chlorbenzol, chlorinated benzol homologues and saturated chlorinated aliphatic hydrocarbons, permitting v the solvent treated mixto settle to thereby attain a top layer predominantly containing a solvent solution of petroleum mahogany sulphonic acid and petroleum hydrocarbon stock and thereafter recovering from said layer a petroleum mahogany sulphonate petroleum hydrocarbon solution of high purity and substantially free from discoloring materials.

oil with an organic and petroleum hydrocar ally liquid ben-v 6. Method in accordance with claim 5 in which said solvent is bcnzol.

'7. Method in accordance with claim 5 in which said solvent is present in volume ratio or" solventto acidified oil from aseaers straight overhead distillate type. having a Say- 7 bolt viscosity at 100 F. of at least 150 seconds with from 15 to by weight of concentrated sulphonic acid at a temperature between 125 and 175 F. to thereby iorm acid sludge, removing said acid sludge, treating the resulting stock with from to 50% of fuming sulphuric acid by weight of hydrocarbon stock present, at a temperature between 80 and 160 F., the total sulphuric acid including concentrated and turning sulphuric acid being from 60 to by weight of said hydrocarbon stock. agitatingthe fuming sulphuric acid treated mix containing acid sludge with an organic normally liquid solvent selected from the group consisting of: normally liquid benzol, benzol homologues, chlorbenzol, chlorinated benzol homologues and saturated chlorinated aliphatic hydrocarbons in volume ratio of solvent to acidified stock from 0.3 l a 'i' .1

settling the solvent treated mix to thereby obtain a layer predominantly containing a solvent solution of petroleum mahogany sulphonic acid, neutralizing said layer to thereby form a top layer predominantly containing petroleum mahogany sulphonate and hydrocarbon oil in solution insaid solvent and thereafter treating said top layer to recover therefrom a petroleum hydrocarbon ml solution of etroleum mahogany sulphonates of high purity and substantially free irom discoloring materials.

9. Method in accordance with claim 8 in which said solvent is benzol present in volume ratio of solvent to acidified stock from i if 1 10. Method in accordance with claim 8 in which said first formed acid sludge is permitted to settle prior to. its removal at a temperature between and 160 F. and in which the solvent treated mix is left to settle and stratify at a temperature between 125 and F.

11. Method for the production of petroleum mahogany sulphonic products which comprises treating petroleum hydrocarbon stock 0! the straight overhead distillate type. having a Saybolt viscosity at 100 F. of at least seconds, with from 15 to 20% of 66 B. sulphuric acid by weight of hydrocarbon stock at a temperature between 125 and 175 F. to thereby form acid sludge, permitting said acid sludge to settle at a temperature between 140 and F., removing said acid sludge, treating the resulting hydrocarbon stock with from 80 to 85% o! oleum by weight of hydrocarbon stock at a temperature between 125 and 140 F. to thereby obtain i'urther sludge formation agitating the resulting mix including sludge contained therein with benzoi in I a volume ratio 01 benzol to total mix oi permitting the benzol treated mix to settle at a temperature between 125 and 140 F. to thereby obtain a first-top layer predominantly containing a benzol solution of petroleum mahogany sulphonic acid and I petroleum hydrocarbon stock, neutralizing said top layer permitting the neutralized top layer to settle to thereby form a second top layer predominantly containing petroleum mahogany sulphonate and petroleum hydrocarbon oil in benzol solution and treating said second top layer to recover therefrom a petroleum hydrocarbon oil solution of petroleum ma-