US1668602A - Process for distilling mineral oil - Google Patents

Description

A. E. PEW, JR., ET AL PROCESS FOR DIST-ILLING MINERAL OIL Filed Feb.- 23, '1924 2 sheets-shewv 1 May 8, 1928.

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A. E. PEW, JR., ET AL PROCESS FOR DISTILLING MINERAL OIL May s, 192s,

Filed Feb. 23. 1924 2 Sheets-Sheet2 4Patented May 8, 1928.

' UNITED STATES 1,668,602l PATENT OFFICE.

ARTHUR E. PEW, JE., or EEYN MAWE, AND HENRY rHoMAs, or EIDLEY PAEH, PENN- sYLvANrA, AssIGNoEs rro SUN 011. COMPANY, or PHILADELPHIA, PENNSYL- vANrA, A CORPORATION or NEW JERSEY.

PROCESS FOR DISTILLING MINERAL OIL.

Application led February 23, 19,24. Serial No. 694,474.

The object of our invention is to provide a process for the fractional distillation of crude oil into gasoline fractions of various gravities, turpentine substitutes and kero- 5 sene. The invention is applicable to the distillation of oil into other fractions of progressively increasing boiling points, and it will be understood that in specifying the above-named lighter constituents of .crude 1o oil, we do not mean to be confined thereto but intend to include any other fractions of different boiling points recoverable by distillation from crude oil, ordistillates therefrom, or residues from such distillation. ,In the drawings, which show .a preferred apparatus for carrying out the process- Fig. 1 is a diagram of the plant. Fig. 2A is a diagram of a form of tower adapted to operate as a vaporizing fractionator. f

Figs.f3 and gare respectively sections on the lines 3-3 and 4 4 of Fig. 2.

In the drawings we have shown five towers and three stills, although the number of towl 26 ers and stills may be yvaried dependent upon obtain. f

Through line a crude oil is pumped from a source of supply (optionally through a heat 30 exchanger b) into a vaporizing fractionator c. Vapors freed herein from oil which are very light, ass to condenserd. esidual oil 1s pumpe through reflux con ensers z', j and k on towers g and h'respectively, and through heat exc anger m to the vaporizer fractionator tower n. Vapors from tewer n go' to condenser o. Residual oil from tower n flows into the vaporizer pans or evaporator pans 40 p in still r. Vapors from still 'r pass into fractionating tower f. Vapors not condensed in tower f go to condenser d, while reiuxed condensate goes to one of the stills, preferably returning to still 1'. Residual oil from still 1' goes to still s. Vapors fromvst-ill .s

pass into the fractioning tower g, vapors uncondensed therein passing to condenser u and reluxed condensate going to one of the stills, preferabl returning to still s. Residual oil from sti s flows into still t., Vapors from still t pass into fraction'ating tower` h, vapors not condensed therein passing to c ondenser 'v and reuxed condensate returnin to still t. Residual oil from still t is pumpe the number of'distillates that it is desired to through line e successively.

through line w and heat exchangers m and b.' One of the objects of the invention is to obtain -rubber gas, which is a light gasoline from which the very lightest fraction has been removed and which contains no heavy gasoline fractions. Another object of the invention is to sepa-rate gasoline suitable for motor propulsion, which gasoline may be obtained by mixing said very lightest fraction with the heavier fraction that must be excluded from rubber gas. The arrangementabove described and the process carried out therein are well'adapted to effect these purposes. I

lhe cold crude oil flowing through pipe a enters the vaporizer fractionator c heated to a relatively low temperature, or alternatively, not heated at all. It is not intended to vaporize in tower c more than about one per cent of the oil. In passing through reflux condenser z', j and lc and through heat ex- 75 changer m, the temperature of the oil is Substantially raised, although not to the temperature in still 'l'. Hence, in tower n, more or less light gasoline will be evaporated and pass to condenser o. With certain crude oils, the proportion of gasoline suitable for rubber gas is something over eleven per cent of the original crude oil, and the tempera-` ture of the oil entering tower n may be regulated, particularly by controlling 'the exchange of heat in exchanger m, so as to insure the vaporization in Atower 'n of this percentage. The fractionating evaporizing tower c is preferably of the type shown in Fig. 2 and comprises circular flanged plates 10 of smaller diameter than the inner diameter of the tower c alternating with annular ianged plates 11 of a diameter nearly or quite equal to the inner diameter of the 95 tower c. Thereby a staggered course is provided for the vapor, which flows through the central orifices in the plates 11 and past the peripheral edges of the plates l0. The exit end of pipe a enters the tower at about its 106" center so that the lower part of the tower acts as a vaporizer and the upper part of the tower as a fructionator. Each plate is provided with an annular group of small holes 12, through which the oil escapes from plate to plate. The vaporizing fractionating tower n preferably comprises three sections: a lower pans p within the still.

section 20, a mediate section 2l and an upper section 22. The lower section 20 may comprise plates similar to plates 10 and 11 in tower c. The mediate section 21 may consist of a tier of fine screens. The upper section 22 preferably comprises a tier of plates, etc., so constructed as to insure the bubbling of the vapors through the oil 1n the passage of the vapors upwardly through the plates. Known constructions are suitable for the purpose. A tower well adapted the purpose is shown in Fig. 1l of an apphcation filed by us (Case 1) of even date herewith, Serial No. 694,470.

Residual oil from tower n flows, as above stated, into the still r. It is preferred not to introduce this oil directly into the body of the oil in the still, but to flow it onto These pans comprise a wide upper pan and two narrower lower pans, both slightly inclined to the horizontal in opposite directions and extending, preferably, the length of the still. The oil flows along the upper pan and the lower pans successively, the lighter fractions of entering oil being vapor-ized thereon, such vaporization being facilitated by the spreading out of the oil over an extended surface in a thin film, by the intimate contact of this extensive film of oil with hot` vapors, and by the heat of the pans themselves. By suitably regulating the still temperature, all of the gasoline in the oil will pass, together with some heavier fractions, into the tower f.

The tower f may have an entirely open interior filled with pieces of clay or other refractory material 30, such as the well known Reschig rings. Vapor escaping through the reflux condenser i and passing to the condenser l may comprise a little over nine per cent of the original crude oil. In this condenser it mixes with the very lightest one per cent of the oil coming from tower `c, the resultant gasoline being well adapted for -motor propulsion. 0f course, if desired, the two`\distillates may be separately condensed before mixing.

The condensate from tower f flows back into one of the stills, preferably still r. Residual oil from still 77 goes to still s, flowing (preferably) directly onto pans p therein similar to pans p in still 7 and functioning in the same way. Vapors from still s pass into the fractionating tower g, the internal construction of which may be the same as the upper section 22 of tower n. By suitably regulating the temperatures of st1ll s and reflux condenser j, the oil condensed from the vapor escaping from the tower will be a suitable turpentine substitute. if an appropriate crude oil, such as Texas oil, is used, and may comprise (say) nearly eleven per cent of the crude oil.

If it is desired to still furtherv fractionate the oil, the condensate from tower g may be returned to one of the stills, preferably still s, andthe residual oil from still s conveyed to still t, flowing, preferably, directly onto pans p therein similar to pans p in stlll fr. Vapors from still t pass into the fractionating tower It, whose internal construction may be thel same as that of tower g.l By suitably regulating the temperatures of still t and reflux condenser lc, oil condensed from the vapor escaping from the tower may be kerosene of any desired gravity, comprising (say) over thirteen per cent of the crude oil.

'lhe condensate from tower lL may go back to still t and the highly heated residual oil from this still may be utilized to substantially raise the temperature of the oil flowing through line e to the tower n. Thence the residual oil may go to storage; or it may be subjected to further distillation. In fact,

it may be further distilled in an apparatus embodying this invention, which, as hereinbefore stated, is adapted'for the fractional distillation of oil from which thelighter fractions have been separated by any process or 1n any apparatus.

Having now fully described our invention, what we claim and desire to protect by Letters Patent is:

l. 'lhe process of fractionally distilling 95 the unvaporized oil and subjecting ittoheat,

vaporizing part of the heated oil and fractionatinrr the vapors at a second locus, conveying flic residual oil and condensate from the locus of said vaporization and fractionation to a body of oil at a third locus, heating said Ibody of oil to effect its partial vaporization, distributing the oil during its flow to said body of oil over an extended surface and in contact with the vapors from said body of oil, thereby partially vaporizing the oil in the course of its flow to said body of oil, fractionating and condensing at a fourth locus the vapors from the last named flowing oil and from the body of oil, and subjecting the residual oil from said body of oil and the condensate from the last named fractionation to further treatment adapted to effect their partial vaporization and condensation.

2. The process of fractionally distilling, 129

oil to produce a light gasoline and a heavier hydrocarbon sufliciently light for use as m05- tor fuel, which comprises establishing a flow of relativelycold oil and durin its iiow sof diffusing it at one locus as to e ect evaporation of a very small' fraction of the oil, flowing away the unvaporized oil and subjecting it to heat, flowing away the heated oil and so diffusing it at a second locusl as to effect its partial vaporization and fractionating 13 l the vapors and condensing them to rovide a light gasoline, conveying the resi ual oil and condensate from the locus of said vaporization and fractionation to a body of oil at a third locus heating said body of oil to effect its partial vaporization, fractionating at a fourth locus the vapors from said body of oil, and condensing the vapors of the first specified, evapora-tion and fractionation and the vapors of the last specified fractionation and making' therefrom a mixed distillate adapted for motor. propulsion.

The process i of fractionally distilling oil which comprises establishing a flow of relatively coil oil and during its flow so diffusing it at one locus as to effect evaporation of a small fraction of the oil, flowing away the unvaporized oil and subjecting it to heat, vaporizing part of the heated oil and fractiona-ting the vapors at a second locus, heating a body of oil at a third locus to effect its partial Vaporization, fractionating at a fourth locus the vapors from said body of oil, and conveying to said body of oil the residual oil and condensate from the second and fourth loci and in the course of their iow distributing them over an extended suriace and in contact with the vapors from said body of oil,lthereby effecting their partial vaporization in the course of their ow 'oil which comprises heating oil and flowing away the heated oil and so diffusing it at one locus as to elfect its partial vaporization and fractionating the vapors, heating a body of oil at a second locus to effect its partial vaporization, fractionating the vapors from said body of oil ata third locusz conveying the residual oil and condensed 011 from the locus of the' h'rst evaporation and fractionation and also`the condensed oil from the last'fractionation to said body of oil andin the iow of such oil distributing it over an extended surface and in contact with the vapors from said body of oil, thereby partially vaporizing such oil `in the course of its fiow to said body of oil and mixing the vapors from such flowing oil with the vapors from the body of oil.

In testimony of which invention, we have hereunto set our hands, at Philadelphia, Pa., on this 14th day of February, 1924.

ARTHUR E. PEW, JR. HENRY THOMAS.

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