US1963488A - Treatment of hydrocarbons - Google Patents

Description

June 19, 1934. E. ELLSBERG TREATMENT OF HYDROCARBONS Filed Dec. 27, 1930 Zjrvuantoc s am/.4 am

Patented June 19, 1934 PATENT nsane FFECE TREATMENT or HYDROCARBONS Edward Ellsberg, Westfield, N. 3., assignor of three-fourths to Tide Water Oil Company, Bayonne, N. J., a corporation of New Jersey Application December 27, 1930, Serial No. 505,027

3 Claims.

In the well-known Edeleanu process of treating mineral oils with liquid sulfur dioxid to remove constituents which are unstable or are otherwise undesirable, it has been necessary to provide means for continually drying the sulfur dioxid, since the latter takes up any water present in the oil, with the result, were it not for the dryingof the sulfur dioxid, that water would accumulate in the system to the detriment of the apparatus besides necessitating interruption of the operation. Special difficulty has been encountered in this respect in the treatment of lubricating oils. In purifying such distillates by the Edeleanu process I have found that it is imperative, or at least necessary in order to avoid heavy expense, that the oil be practically chemically dry. I have, therefore, sought to find a way of making the liquid sulfur dioxid process practical for the treatment of distillates of this description, that is to say, finished or semi-finished oils heavier or more viscous than kerosene and containing no, or substantially no, low-boiling fractions.

Such oils may be expected to contain small fractions of water running up to six-tenths of one percent, 0.4%-0.5% being ordinary. The removal of small residual moisture contents from these hydrocarbon distillates is a special problem. There' are various processes for separat- 301mg the bulk of water from crude oil and the like containing much water, for treating emulsions, and for taking off both water and light hydrocarbon fractions from material on the order" of crude oil, but such processes deal with different material than thosewith which this invention is concerned, and they do not produce a truly dry oil.

In the case of distillates such as motor and other lubricating oils, turbine oils, transformer *1'0115, cable oils andthe like, containing residual moisture, or moisture absorbed from the air, the general practice, whenever a fairly dry oil has bee'n'requiredjthat is to say one having no more than about 0.4% water or less, has been to heat 45, the 011' in a tank by means of steam coils while blowing air through the body of the oil. This operation requires ten to thirty hours of time, the oil is frequently oxidized and injured by the heat and by the action of the air, and the at- 501tainment of any exacting degree of dryness is not only difiicult but uncertain. The moisture in the air is often sufficient to defeat the operation, and for lubricating oil which should not contain more than about 0.1% moisture when 55, shipped, it is 'often necessary to defer drying until a day when the atmosphere is sufficiently low in humidity. I appreciate that quicker modes of drying distillates have been proposed, but as far as I am aware they have not been used, or used to any general extent, notwithstanding the great 'need for a fast and efifective method of drying distillates such as those contemplated in this application. It seems probable, therefore, that such methods either proved to be inefificient or unduly expensive or that they resulted in injury to the distillates, which when finished or partly finished are susceptible of de dried is immediately cooled and then treated with remove the undeliquid sulfur dioxid to sirable hydrocarbons. Theentire process is carried on continuously without at any time heating the oil to a temperature greater than about The accompanying drawing illustrates schematically an apparatus for carrying the invention into effect.

The distillate, which may be of a viscosity ranging from 40 seconds at F., Saybolt Universal,

to or seconds at 210 F., Saybolt Universal,

and which has a moisture content usually not over 0.6%, is fed by a pump 2 through a line 3 to a heat-exchanger ,4, where it is partially heated, as for example to about 130 F. Thence it passes througha connection 5 to a heat-exchangeryor other heater, 6, where it is heated in transit, pref erably to about F. to 200 F. 7 is a line for conducting exhaust steam or other heating-fluid to the heat-exchanger 6, to bring the temperature of the oil up to the required moderate degree without heating it sufficiently to causeinjury, and 8 is a discharge line for the heatingfiuid'or water of condensation.

'The heated oil proceeds from the heater 6 through a line 9 to a vacuum chamber 10. This is preferably an upright tower or tank containing bafiles 11 over which the oil admitted at 12 flows downward in a shallow stream or film. Upper bafiles lS'may be provided for restraining any particles or vapors of the oil which might otherwise escape through the top exit 14 connected with vacuum line 15. Instead of flowing the 'oil over baffles in the vacuum chamber, it may be attenuated by spraying it into the chamber, it being a desideratum to liberate the water vapor freely from the more or less viscous material without requiring it to struggle through any substantial bulk of oil.

The dried oil is withdrawn from the moderate sized body 1 6 which collects in the bottom of the vacuumizer, either by gravity if the tank is set, high enough, or preferably by a pump 17 which causes the dried oil to flow through a line 18 to the heat-exchanger 4, where it is cooled by exchange with the oil to be treated, preferably to being too well known to require illustration-and description. The Edeleanu apparatus includes a cooler or coolers for the feed oil and consequently the cooler 20 need not chillthe oil to the final;

temperature required for that treatment.

Thewater vapor liberated from the oil in the vacuum chamber 10 is withdrawn, and the-vac-- uum is maintained, preferably by a barometric r jet condenser 24 connected with the vacuum line 15., this condenser being proportioned andf-dea signed to create a vacuum in the chamber upwards of about 26 inches-of mercury A water line Z'Ssupplies Wamr to the body of the condenser, and a steam line 31 supplies steam jets at the top of the condenser and ma branch 26 of the condenser. The water vapor is condensed in the body of the condenser and passes with the waterof the top water jet down through the limb 27 0f the, condenser to a collector 28, fromwhich the water may be conducted through a pipe 29 to a sewer. The non-condensable hydrocarbon vapor or gas present, which might tend to accumulate and adversely affect the vacuum, is entrained by the steam jets in the branch 26. and carried through a 1ine 30 which may connect with the discharge line 29. It will be understood, however, that the barometric condenser illustrated is only one form of means for maintaining the vacuum in the chamber 10, andthat any pumping equipment. capable of maintainingthe requisite vacuum mime used instead.

The. employment of a comparatively high vacuum is essential to reduce thetemperature which is required to expelthe water as vapor from the oil. I have. ascertained that it is necessary to heat the oil to a temperature about 40 F. abovev the theoretical boiling point. at the'absolute pressure inthe. chamber, this differential being illustrative sin'ceit may be varied for different de grees of; vacuum and for different materials. On

the other hand the temperature of the oil should not be allowed to go above about 200 F. for the average oil. Temperatures much above that have.

' deleterious effect upon the color, flash-point or lubricating qualities of the. oil.v Even atthese moderate temperatures it highly desirable that the oilbe heated, dried and cooled, r pidly thisjprocess, the entire sequence of, these opera? tions. canbe. performedin less than one minute,

to be a limitation, it is important, to keep the material ata moderate temperature for only a short'penod; r

Within limits. on the orderof. those indicated. herein the temperature and vacuum conditions are correlatively variable, and they maybe varied also in accordance with the particular materials to be treated. For efiective. and satisfac'.

tory results it is desirable that the vacuum be. upwards of about 26 inches of mercury. If I the" moisture, but substantially-no low-boiling hydroture but substantially no low-boilinghydroeare vacuum is not sufficiently high the; oil will not be adequately dried even though; thev temperature be raised :to a pointat which injury to .lthe oil is. likelyto result. Asa preliminary treatment in the Edel'eanu. process it is of the greatest importance that these, oils be rendered practically chemically dry, so that any moisture remaining is less than about oneone-hundredth of one per .cent. This is accomplished by the process, as is illustrated by the following example:

A medium motor oil having a viscosity of 300 seconds atl00 F., Saybolt Universal, is dried to 0.005% remaining moisture at a temperature of 180 F, and a vacuum corresponding to'28 inches of mercury;

Theinvention maybe applied to the drying of finished or semi-finished oils refined by different methods, and in such casesthe drying may be less thorough. V Y a it will be understood that modifications in the. process and in the apparatusare permissible and that the language used in the following claims is intended to cover all-the generic and specific novelty of the invention, and all statements-of, the scope of the invention which as ,a matter of 109; language might be said to fall between, the claims;

I claim: '1. The process of treatin lubricating oils or; other mineral oil distillates which ,contain carbon fractions, which comprises quickly heating such distillate and subjecting -it. .to.:a;vac uum, the combined conditions of temperature and vacuum being such that the moisture in the, oil is. eliminated and the oil is dried to belowi 1 0.01% moisture Without heating the oilat any .timetoatemperature aboveabout 2.00?:

, 2. The process of treating lubricating oils 6r} other mineraloil distillates which contain moisbon fractions, which comprises. quicklyheating such distillate and subjectingitto a. vacuum, the

ccrnh ed conditionsaoftemperature and. vac.-

uum eing such that themoisture in the-oil is: eliminated .and the. oil is dried tocbelow 0.01%.

. s ur wi o the t ;t .e. .9 .-a ermine $92 -a temperature above about 200 Rand quickly; pooling the dried oil, the entireoperationpi-heating, drying andcooling each portion of the. oil] being performed in a period notsubstantially in excess of one minute, so. that the-timeduringx which the oil remains heated isasshcrtaspessiblelandne deterioration oi the ualities; cf the oil occurs. 2 lg) 3.'The-process of removing small fractions oh-13g. water from lubricating oils or, other mineraloil :distillates whichcontain substantially no low,-

boiling hydrocarbon fractions, which c rnprises], quickly heeting; such distillate; Lucid Frying the same b-y subjectingitto afvaeuum not less or more above the boiling'point of Water at the not exceeding about 200 F.-'.,;the combined-cor ditions; of temperature and vacuum beingsuch oil is dried below 0.01% moisture without -heating the oil atany. timeto a temperature abovev about 200" FL, and quickly cooling the dried distillate. V

. EDWARD LLsB-ERG.

than about 26;1nchesv of merctu z' ihetemperaey and wliile so brief a time as. that is not intended.v inure to which the oil is heated beingabout 49 F. I

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