US1866666A - Pyrolytic decomposition of hydrocarbons - Google Patents

Description

Filed Feb. 2'7, 1928 Patented July 12, 1932 rm: 1!. ovrrz. or wm'mre: mung-manor 'ro erammnn on. courm, or

wmrme, nmnuu, a ooarom'rrou or mnnum momma nnoourosrrrou or none cannons Amman; mar rem-mi am nes. senor. 257,854.

This invention relates to yrolitic decomposition of hydrocarbons an' particularly to theprevention t corrosion of the metallic apparatus employed for suchdeoom o' sition. he invention willreadily be an erstcod from the following description in 0l1nootion withthe accompanying drawing which shows diagrammatically an apparatus whereby hy- "char 'coillO. The outlet of the heating coil' 10 leads into the conversion'chaniber '11,

which is maintainedat a desired cracking".

drocarbon oils may be pyrolptically decomposed and the resulting pro ucts recovered.

Referringto'the drawing, 10 is a heating coil;'-11 is a retorfior conversion-chamber;

12-is the refluxcondenser for overhead from said chamber; 13 is aflash drum for tar from chamber 11 14 is a filter for the residue from said flash drum; 1.5 is a fractionating com denser for the overhead from the flash drum; 16 is a receiver for the bee "condensate therefrom; 17, is a tank in whlch a ortion p of said condensate is adapted to be c :11 ed with hydrated iron oxide; and 18 is :a eed pipe leading to the heating coil 10. w a

A mp 19 is provided for supplying g stock under pressure to the eating temperature by burners 21. The; convers on chambrdl 1s suitably-provided with a.

flux' condenser with suitable scraper 40 for the of. removing coke iorming material rom the walls thereof and oausin' it to fall to the bottom of thechammm the upper end of the conversion 22 leads to the re- O 0., v- Q ftfitlonatlilgi-mid oondensi devices (not she condenser 12 through line 28 by 'ump 2'3 toithe heating coil 10; Frointhe ower end of the conversion chamber 11- a pi e'24-lead's to the dash drum 13, said pipe 24' eing rovided witha valve 25. From the top o the drum13 a pipe' 2firleads to thejlower artline 38;

A vapor pipe 42- lea s fromthe to of the iractionating condenser 12 to a suite l'e condenser (not shown). Re- 11111: condensate may berreturned from the thiscondenser a pipe QT'Ieadsinto.

the receiver-16 and fromthe-to thereof a pipe 43 leads toa suitable con enser (not shown From the'underside of the drum 13 a P1pe28 leads .into the filte'r14. A suitable pump,'for example, at hot oil pump29 is provided in the line 28 for forcing 'thepressure tar residuum into the filter 14.

The filtered pressure tar residuumpasses V from the filter 14 by pipe30.

Theheav pressure tar distillate receiver '60,

y The tank 17 is providedfwith a perforated on pipe 34 which is adapted to inject air into the contents' thereof. From a low position on-the tank 17,'a pipe 35,1eads to the upper ortion of said tank.- Said pipe 35 is provided with'a circulating ump 36'and a hop .70

per 37 b means of yv ieh hydrated iron oxide an other substances such as water,

may be added to the oil circulated bythe pump 36 and may thereby be disseminated throughout the oil in tank 17. From the bottom of tank 17, 'a' pipe 38 leads into the feed lihe18.

'Theoperat-ion follows:

Heavy pressure tar distillate g mp 3- v h d -o tillate is then circulated through the 35 by pump 36 from-thebottom tothe top of the ya tank 17. 'Hydrated iron oiiide; in finel divided foi'm is fed into the circulating 011 y by the hopper ;37 and is carried by the oil"- culati'ng oil by the hopper' 37 andis'c'arried' by theeirculating oil'into tank 17. A pertain amount of .water may then )be. supplied hopper'37, if desired, said water assisting also. preferablywhile it is being usedrthe'oil in the tank 'l'l is agitated by air introduced bythe perforated pipe 34." It is preferred to;

produce irithis manner a'suspensionof iron oxide-containingiapproximately1,5 lbs! per 1 9,

A pump 89'i's'prov ided the v 4 islr p .from receiver 16 through line 32 by into tank 17 until it is nearly full somewhat in the production of a satisfactory. suspension-of the ironoxide in the oil.

While the suspension is being produbedjandg 5 gallon. The amount of waterused may suitabl be about 0.8% b volume of the 011.

he charging stoc which is supplied to the heating 0011 10 through line 18 by the pump 19 mal be any suitable hydrocarbon oil heavier t an gasoline, such as gas oil, garaiiin light ends, pressure tar distillate, eavy paraflin distillate, or mixtures of two or more thereof. The oil containing suspended hydrated iron oxide is fed to the charging stock through line 38 by the pump 39 in quantity suflicient to provide a suitable oxide content in the oil passing through the heating coil 10 and conversion chamber 11. A suitable quantity of oxide is approximately 0.5 lbs. per arrel of charging stock i. e. about 0.17% by weight. It must be understood that this amount will vary with stocks of different character and origin, but the proportion of such oxide ordinarily will not exceed a fraction of 1% relative to the wei ht of the oil.

e temperature and pressure conditions in the heating coil 10 and the conversion chamber 11 may var within wide limits. For example, the out et temperature of the heating coil 10 may suitably be about 820 to 850 F. and the pressure may suitably be about 325 to 400 lbs. per square inch. The chamber 11 may be heated by the burners 21 to maintain a suitable cracking temperature therein.

The fractionating condenser 12 is controlled to give a pressure distillate of the desired character, the vapors of which pass off by pipe 42 and are condensed. The reflux from condenser 12 is returned to the heating coil 10 through pi e 23 by ump 23.

Pressure tar 1s rawn oil from the bottom of chamber 11 and is accompanied by more or less coke which is reduced in the oil, as well as iron oxide an iron sulfide which are disseminated in solid form in the coke and in the tar. The withdrawal is effected con' tinuously, or periodically, through the valve 25 and pipe 24 and the tar is flashed in the drum 13 which is maintained substantially at atmospheric pressure. The overhead passes by a pipe 26 to the fractionating condenser 15 in which the heavy pressure tar distillate is condensed, the condensate passing by pipe 24 to the receiver 16. The light pressure tar distillate vapors pass by pipe 43 to a suitable condenser (not shown).

Ordinarily, only a small part of the heavy pressure tar disti late is used in the tank 17 or the production of the suspension of iron oxide in oil; the remainder is withdrawn by pipe ,31 to be used in producing blended charged stock.

The ressure tar residue is pumped in a hot condition through pipe 28 by pump 29 into the filter 14. Ordinarily it is preferred to use a pressure filter,'but an other filter may be used. Among others, ters of the Sweetland and Kelly type are suitable. The filter surfaces may suitably be constituted by woven metal, such as fabrics woven from steel, copper, brass or other suitable metallic wire.

The hydrated iron oxide combines with the sulfur and sulfur-com ounds which exert a corrosive elfect upon the metal of the ap aratus so that internal corrosion from t is cause is substantially prevented. The proportion of hydrated iron oxide is so small that the fluidity of the oil undergoing treatment is not substantially im aired. Further, the h drated iron oxide an iron sulfide produce therefrom, together with the coke, constitute a suitable filter medium which materiall aids in preventingpassage of other soli material while permitting the liquid ginstitunt of the tar to pass through the ter.

While I prefer to employ hydrated iron oxide, it must be understood that iron oxides and other oxygenated compounds such as carbonates, which will react with sulfur and sulfur compounds under the conditions of the operation, may be employed in finely divided form according to the invention.

Although the present invention has been described in connection with the details of a specific embodiment thereof, it is not intended that such details should be regarded as limitations on the scope of theinvention except in so far as included in the accompanying claims.

I claim:

1. In the art of converting hi her boiling hydrocarbon oils into lower boilin hydrocarbon oils wherein such oil is sub ected to cracking conditions of temperature and pressure while confined within metallic apparatus, the method of reducing corrosion of said metallic apparatus by the said oil undergoing cracking which comprises maintaining in the presence of said Oll under oing conversion, hydrated iron oxide in t 1e amount of not more than a fraction of 1%.

2. In the art of converting higher boilin hydrocarbon oil wherein such oil is subjecte to cracking conditions of temperature while flowing through a confined metallic passageway and is passed therefrom while at a cracking temperature to an enlarged metallic chamber wherein it undergoes further cracking, the method of retarding corrosion of said metallic passageway and said metallic chamher by the said oil undergoingcracking,which comprises admixing with the oil, prior to its introduction into said metallic passageway, not more than a fraction of 1% of hydrated iron oxide.

3.- In the art of converting higher boiling hydrocarbon oils into lower boiling hydrocarbon oils wherein such oil issubjected to cracking conditions of temperature and pressure while confined within metallic apparatus,

the method of reducing corrosion of said metallic apparatus by the said oil undergoing cracking which comprises maintaining 1n the presence of said oil, undergoing conversion an amount of not more than a fraction 0 1% of h%drated iron oxide substantially free of absor ed alkali.

4. In the art of converting higher boiling hydrocarbon oils into lower bollin hydrocarbon oils wherein such oil is sub ected to cracking conditions of temperature while flowing through a confined metallic passageway, said oil bein passed from said passageway while at crac mg temperature to an enlarged metallic chamber wherein it undergoes further cracking, the vaporous products of conversion and the heavy liquid residual products of conversion being separately withdrawn from said chamber and the latter products being assed through a filter element, the method 0 retarding corrosion of said metallic passageway and chamber by the said oil undergoing cracking, which comprises admixing with the oil, prior toits introduction into said passageway, not more than a fraction of 1% of hydrated iron oxide.

5. The method of decomposing hydrocarbon oils w' 'ch com rises cracking the oil under pressure, wit drawin liquid products and assing t em to a zone of lower" pressure w erein light and hea fractions are formed, mixing 1101'1 oxide wit said light fractions, and rethrning said mix ture to the oil being cracked.

In witness whereof I haveunto set my hand this 9th day of February 1928.

FRAN K. OVITZ.

unvaporized CERTIFICATE OF CORRECTION.

Patent No. 1,866,666.

July '12, 1932.

FRANK K. OVITZ.

it is herebycertified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, line 55, for "at" read a; same page, lines 58 and 59, should not appear as a separate paragraph but should follow' "filter 14." in line 57; line 83, for "the" read pipe; and lines 88 and 89, strike out the words "by the hopper 37 and is carried by the circulating oil"; and that the said Letters lfatent should be read with these correctiohs therein that the same may conform to the record 'of the case in the Patent Office.

Signed and sealed this 1st day of November, A. D. 1932.

(Seal) Mu]. Moore, Acting Commissioner of Patents.

the method of reducing corrosion of said metallic apparatus by the said oil undergoing cracking which comprises maintaining 1n the presence of said oil, undergoing conversion an amount of not more than a fraction 0 1% of h%drated iron oxide substantially free of absor ed alkali.

4. In the art of converting higher boiling hydrocarbon oils into lower bollin hydrocarbon oils wherein such oil is sub ected to cracking conditions of temperature while flowing through a confined metallic passageway, said oil bein passed from said passageway while at crac mg temperature to an enlarged metallic chamber wherein it undergoes further cracking, the vaporous products of conversion and the heavy liquid residual products of conversion being separately withdrawn from said chamber and the latter products being assed through a filter element, the method 0 retarding corrosion of said metallic passageway and chamber by the said oil undergoing cracking, which comprises admixing with the oil, prior toits introduction into said passageway, not more than a fraction of 1% of hydrated iron oxide.

5. The method of decomposing hydrocarbon oils w' 'ch com rises cracking the oil under pressure, wit drawin liquid products and assing t em to a zone of lower" pressure w erein light and hea fractions are formed, mixing 1101'1 oxide wit said light fractions, and rethrning said mix ture to the oil being cracked.

In witness whereof I haveunto set my hand this 9th day of February 1928.

FRAN K. OVITZ.

unvaporized CERTIFICATE OF CORRECTION.

Patent No. 1,866,666.

July '12, 1932.

FRANK K. OVITZ.

it is herebycertified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, line 55, for "at" read a; same page, lines 58 and 59, should not appear as a separate paragraph but should follow' "filter 14." in line 57; line 83, for "the" read pipe; and lines 88 and 89, strike out the words "by the hopper 37 and is carried by the circulating oil"; and that the said Letters lfatent should be read with these correctiohs therein that the same may conform to the record 'of the case in the Patent Office.

Signed and sealed this 1st day of November, A. D. 1932.

(Seal) Mu]. Moore, Acting Commissioner of Patents.

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