USRE7096E - Improvement in heavy hydrocarbon oils for illumination - Google Patents

Description

UNITED STATES PATENT OFFICE,

RUFUS S. MERRILL, 0F CAMBRIDGE, MASSACHUSETTS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO WM. B. MERRILL, JOSHUA MERRILL, AND RUFUS S.

MERRILL.

- IMPRdVEMENT m HEAVY HYDROCARBON OILS FoR ILLUMINATION.

Specification forming pnrt of Letters Patent No. 100,915, dated March 15, 1870; reissue No. 7,096, dated May 2, 1876; application filed March .8, 1876,

To all whom it may concern Be it known that I, Runes S. MERRILL, of

Cambridge, in the county of Middlesex and State of Massachusetts, have invented a cer-- tain new and useful product obtained from the distillation of coal, shale, and petroleum,

and having a very high igniting and fixed distilling-point, being an oil which, possessing properties of great value and importance as a cheap, safe, and brilliant illumination material, constitutes a new commodity or. article of manufacture and trade heretofore unknown, and not sold or. used as such.

In the specification annexed-reissue, Division A, of my Letters Patent No. 100,915, dated March 15, 1870-1 have described a method of burning such oils for illuminating purposes, an invention or discovery which led me to experiment upon methods to produce on a manufacturing scale-that is to say, with a degree of certainty and economy-an oil possessing the qualities before indicated, which may have v and has been produced in the manufacture of other products of distillation incidentally or accidentally, without any known rule or method therefor, and which were useless, and the production of which was therefore avoided as much as possible.

In order to fully understand the nature of my invention, it will be necessary for me to describe the processes usually practiced in the manufacture of petroleum and such like hydrovcarbon oils, and to show wherein my present invention difl'ers from them. 1

The process may be divided into two classes, as follows: First, the distillation known as the fcrackiug process, when the object is to make from the crude oil the largest possible oil.

DIVISION B. l

vessel provided with a suitable condensing apparatus, and when the manhole-plates are properly secured a fire or fires are started under the still. The oil when sufficiently heated begins to vaporize. The vapors arriving in the still pass over through the condenser, and are condensed againinto liquid. The first to pass over is naphtha of very light gravity, and is very volatile. This is allowed to run into suitable tanks, until the gravity reaches about 60 Baum at 60 Fahrenheit. At this point the stream lrom the condenser is changed into another tank, and the distillation continued so long as the oil runs comparatively white in color, and of a gravity of about from 42 to 43 Baum. At this point the oil begins to grow yellow in color, audfeels slightly oily between the thumb and finger, and it is at this stage of the distillation that the cracking process, so called, begins. The fires are reduced under the still by damping, and the stream of oil flowing from the condenser is greatly lessened, the process being so conducted that'the heavy oil remaining in the still is lifted in vapors, and again condensed in the still, and falls back, to be again and again vaporized and condensed, the lighter vapors, which are formed by this process, alone passing over to the condenser and out at'the outlet. These lighter vapors when eondensed form an oil of much the same general characteristics as that already distilled over for burning oil, being of light gravity of about 45 or 46 Baume, comparatively white in color, thin in body, and mobile like kerosene- This process is continued until only from fi-vc to eight per cent. of the crude oil placed in the still is left in the form of a black residuum, which, when sufliciently cooled after removing the firesfrom under the still, is drawn 011' and usually again distilled, to be manufactured into parafline-oils, and sometimes the parafline-distillates are again returned to the crude oil, to again go through the cracking process, until eventually-it is all cracked up into thin and low lire-test,"'or ordinary kerosane-oil, or refined petroleum.

and flows out a liquid.

is, ruin the cracking process, naphtha. This- The second process referred to, known as. the fractional distilling process, is directly the .reverse of the one just described, and iszdcsigned to separate petroleum into its various products of naphtha, kerosene, par-afline, lubricating-oils, and para'fiine-wax. In working by this process the crude oil is placed ill-a suitable distilling apparatus, to which a con- 'densingcoilorpipesarcsecured, the samepractically as is used in the process first described.

Crude oil is placed in the still, usually filling it two-thirds to threequarters full,'-and a fire started under the bottom of the still, and the oil heateduntil vapor arises and passes over to the condenser, when, coming in contact with cold surfaces, the condenser being immersed in cold water, which is constantly renewed from a supply-tank, the vapor is condensed The first to pass over is allowed to run into a suitable tank until the gravity reaches about 60 Baume hydrometer.

The fire being continued. under the still, the

- distillation goes on as at first described, and the stream of oil being at this gravity conducted into another tank forkcrosene oil the distillation goes on precisely .the same as in the process first describediuntil the burn-' ing or kerosene-oil portion is all distilled over, whichis knownv by the oil growing slightly yellow in color and heavy in gravity. The kerosene orburning oil usually embraces the portion distillingover between 60 and 42 to 43. Baum, and from sixty to'seventy per cent.-0f thee'rude oil placed in the still is dis;

tilled over in the form of naphtha and burning or kerosene oil.

Up to this stage of the distillation the processes have been conducted precisely alike; 'butnow theessential difference .of the fractional distillation from the" cracking process begins. Instead of now-reducing the fircsunder the still, and ,so conducting the process-of distilling that the cracking of the heavier oils lci'tin thestill will be the result,

thefirc is somewhat increased, and the dis tillation goes on rapidly. The stream of oil from the condenser is conducted into] a suitable tank' until about.38 to 369 Baum is reached. This oil coming over from '42? to 36 Baum I call intermediate oil, which istoo heavy and fixed for kerosene or the ordinary refined petroleum-oil, and too light and thin for lubricating-oil,

the stream'of oil is again changed into a suitable tank, and distillation carried on in as rapid a manner as possible to prevent crack ing of the oil, and it is continued until the oil is all distilled over, or until a small quantity of residuum is left in the still. The last-named oil-that is'to say,'the oil that passes ever between from 36 to 38 Baum, andthe final finishing of the distillation-isparafline-oil, heavy in body and gravity, containing abundance of paraifiue, which, by suitable Orwell- To this I shall refer further on, as the product I produce from'it constitutes the invention [have made. After the gravity reaches from 36 to 38 Baum,

known process, is made into .the paratiine lubricating-oil of com mercc.

oil usually comprises that portion of the frac-' tional distillation of hydrocarbon oils between 42 and 36 Baum. Q

I, It has been the cnstom'of manufacturers of oil to subject this oil to the crackingprocess, in order to make it into' thin illuminating-oil,

like kerosene. 'It is also frequently put back into crude oil, and with the whole mass of oil subjected to the cracking process, and thus allowed to mix .with the products of distillation of the'crude oil. -By these processes it is gotten rid of and utilized. It must be borne in mind that when this intermediate oil is :mixed with kerosene w-ithout-the'prdcess of cracking'it into thin oils being applied to .it, it greatly injuries the kerosene, causing itto change in color, toburn badly in lamps, 2'. c., crusting thcwicks and causing the flames to fail when the oilis only slightly reduced in the lamp. Although it has, in past years, been somewhat resorted to, to mix it with the kerosene, it is not so practiced at the present time, but it is subjected to the cracking process either alone or mixed with crude oil, and so worked until it is finally all crackdd up and lost sight of in the mass of oil produced.

Attempts have been made to utilize this oil by mixing it withthe heavy paraffiue oil, before alluded to, and naphtha, and by subjecting the mixture to distillation; but an inferior; and dangerous oil has been the result of this mixing and distilling process. 7 The heavy oil passing over under the influence of the higher temperatures, is, however,

'variable in its nature as to densityand firetcsts. From oils having the desired fire-test of 200 Fahrenheit, oils of higher, and for illuminating purposes impracticable, points of ignition are reached. On the whole the quan- A ftity of heavy oil which answers the condition of my invention is so small that it would be impracticable to collect it for the purposes of commerce and trade.

To obtain-this oil inany desired quantity. and of a permanent character as to the requisite fire-test, I proceed asfollows: -I take the intermediate oil, "so-called, which is really I a combination or mixture of heavy oils of various densities and boiling-points, and redistil it at a comparatively low temperature. The vapors are passed through a condenser and liquefied.

. The intermediate oil may thus be almost entirely converted into heavy oils of the desired consistency and fire-test. Only a comparatively small quantity of very heavy oil will remain in the still, which may be used as, or made into, an excellent lubricating oil by processes it is unnecessary here to describe,

The oil thus produced burns withgreat beauty and brilliancy, with aKvhite and highlyilluminating flame when burned in suitablyconstructed lamps; and the oil so produced has the following new and valuable qualities I now refer to the intermediate oil alluded to before; This high distilling-point;

high igniting-point, and will not that render it of greet art as a new manufacture heretofore known or used:

flammable vapors at any 200 Fahrenheit;

road-cars, factor es,

second, it

ractieal value in the and commerce not hasa very give ofi' in-- temperature below third, it is perfectly safe for illuminating purposes for steamlighting rail-- ships, and for other domestic uses; it re safe to transport and store; fourth-it gives light when burned lamps; fifth, cally.

tained at a cost of less hour.

a beautiful white in suitably -constructed p and burns economi- In actual practice a lamp giving the light of twelve sperm candl es can be mainthan one cent per Having thus described my inveution, what i claim, and desire to secure by Letters Patent,

RUFUS S.MEBBILL.

I Witnesses: I

Josnu Davmson,

Mmir Hommaswoaern.