PETROLEUM - C&EN Global Enterprise (ACS Publications)

Nov 4, 2010 - First Page Image. THE recent and continuing spectacular increase in the production of aliphatic chemicals has stimulated the interest of...
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J. H . B O Y D , JR. 1 , Phillips Petroleum C o . , Bartlesville, OUIa.

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T h e old economic factors of s u p p l y and demand govern price a n d it is axiomatic in all industries t h a t t h e customer pays for a n y new installation justified o n t h e basis of his business. To u n d e r s t a n d better the economic limitations a t t e n d a n t on t h e u s e of Hydro­ &ψζ2&ίΐα ΉίΜΜ&ί w&si p/v&fSzaœzâ.... ôtU&i psi&clw&tà. GAtaiLsMls. f2a&ÎaÂGA~ carbon intermediates from petroleum it i s desiiable to consider the n a t u r e of ttae ma­ jor source material, crude petroleum (Î, 4, #, 9). Crude petroleum i s a mixture " T H E recent and continuing spectacular converted by chemical processing into of h y d r o c a r b o n s which distills continuincrease in the production of aliphatic salable products. T h e use of natural gas ously a t atmospheric pressure from about chemicals has stimulated the interest of and oil for fuel purposes is familiar to all. i00° F . on u p to 6o0° or 700° F. where chemical companies in the petroleum inCarbon black, essentially elemental carthermal decomposition begins. Conimerd u s t r y as a source of raw materials for bon, is formed in t h e incomplete combuscialîy, t h e higher boiling petroleum fracchemical manufacture. Petroleum is the tion of n a t u r a l gas and is a n important tions can be distilled without decoojposi most i m p o r t a n t source of aliphatic hydroarticle of commerce, vital to t h e manufaction only u n d e r high v a c u u m , arad t h e carbons. T h e term " p e t r o l e u m " as used ture of most rubber goods. Elemental residues c a n n o t be distilled a t all. The here includes mixtures of gaseous, liquid, hydrogen for a m m o n i a synthesis is obpetroleum p r o d u c t s of commerce a r e preand solid hydrocarbons of mineral origin. tained by the high-temperature cracking of pared from t h e crude b y a complicated T h u s , n a t u r a l gas, natural gasoline, and n a t u r a l gas or by reforming natural gas series of operations in which distillation, crude petroleum fall within this definition. with steam. Another use of petroleum cracking, absorption, polymerization, a l N a t u r a l gas is a naturally occurring gasefractions is as cracking stock for the manuleviation, hydrogénation, dehydrogeoation, ous m i x t u r e of hydrocarbons dominantly facture of ethylene and, potentially, of desulfurization, chemical treating, crysm e t h a n e b u t including hydrocarbons conacetylene. These materials are n o t now tallization, adsorption, solvent extraction, t a i n i n g u p to 8 carbon atoms. A gas is and solvent precipitation m a y \>& emsaid t o be wet or rich when it contains a Table I. Typical Crude Petroleum Fractions ployed in various combinationsrelatively large proportion of the heavier BOILINO RANGE, Normally, crude petroleum is first dishydrocarbons. T h e heavier hydrocarbons ο F CARBON ATOM» FRACTION tilled into several fractions $*κ further containing from 4 to 8 carbon a t o m s can 80-450 Naphtha 3-13 processing. T h e lightest fraction is called Kerosene 12-16 330-530 be economically recovered from t h e gas G a s oil 15-20 450-625 n a p h t h a , next kerosene, t h e n g a s oil, b y oil scrubbing, to form n a t u r a l gasoline, Lubricating 550-518 at 1 mm. 19-37 oils lubricating oil fractions, and finally t h e which also contains substantial quantities U p to 7 0 or m o r e D o e s not distill Residue undistillable residual oils. X h o typical of e t h a n e a n d propane. Crude petroleum boiling ranges a n d the a p p r o x i m a t e cor­ is a fluid mixture of essentially normally responding ranges of carbon atoms per economically susceptible to bulk trans­ liquid hydrocarbons, also containing dismolecule for each fraction a r e given i n portation and m u s t be consumed at the solved hydrocarbon gases and solids. Table I . These fractions a r e t h e feed point of manufacture. Another group of Individual hydrocarbons m a y contain stocks for t h e further refining operations hydrocarbons m a y be called t h e transport­ from 1 to over 70 carbon atoms per molerequired to m a k e commercial products. able intermediates, which a r e analogous cule. T h u s there is no sharp line of dist o t h e established chemical intermediates tinction between t h e several forms of peT h e chemical complexity of thos-e frac­ of commerce, and in fact are a new and t r o l e u m — n a t u r a l gas, natural gasoline, tions becomes the more a p p a r e n t whe^ growing division of t h e organic interme­ a n d crude petroleum—but these cateconsidering t h e extreme r a p i d i t y with diates. gories are useful in the classification of hydrocarbon mixtures. T h e hydrocarbons Petroleum as a source of r a w materials Table IS. Possible Structurai horaaers of in crude petroleum are frequently assofor chemical industry is too broad a s u b ­ Several Homologous Series of Hydro-carbonc ciated with relatively small proportions of ject for full discussion here. Consequently, ( I n c l u d e cis a n d trans isorci-era) organic compounds containing oxygen, this paper is limited to the transportable No. OF MONONUCLEAR nitrogen, or sulfur b u t these are ignored in hydrocarbon intermediates available to CARBON ATOMS .MOWQCYCLOPARAFFIN S this discussion. the chemical industry, in order to give P A R A F ­ PER Aliphatic NTTJCLBAB FINS MOLE­ specific consideration to basic factors gov­ mono· C, C s À.B0MA.TT h e organic chemical n a t u r e of peCULE IC8 (8) oiefina r i n g ring erning their supply. E m p h a s i s will be on troleum .nakes it of greatest interest to the 1 1 naturally occurring hydrocarbons, as they 2 1 organic chemical industry which m a y use i1 3 1 m o s t simply illustrate the principles in­ i t as fuel, as a source of elemental carbon 4 2 4 volved. F o r any specific hydrocarbon 5 3 6 ' 1i a n d hydrogen, a n d as a source of hydro6 5 17 1 these factors are: (1) coiuposition and 'iI 7 9 36 6 1 carbons for the manufacture cr separation 8 IS 92 16 8 4 cost of t h e raw material, (2) q u a n t i t y and of hydrocarbon intermediates which are 9 35 22 8 quality of hydrocarbon desired, and (3) 10 75 21 16 10.359 processing steps required a n d their rela­ 24 14 X 10» ι P r e s e n t address, H y c a r Chemical Co., Akron tion to existing refinery operations. , Ohio. V O L U M E

23,

NO.

4 n

S

F E B R U A R y

25,

H 4 5

345

which the number of hydrocarbon isomers increases with increasing molecular weight. T h e simpler homologous scries of h y d r o carbons occurring in petroleum arc the paraffins, the olefins (by pyrolysi.-o, the (' b and K\ ('veloparailins, and t h e mononuclear iiroiuatio. Inspection of Table II ..iio\v> that the theoretically possible ninulxT of isomers for a n y serie> will reach as'ronomic a miigiMt udes in the ('._,., or lubricating oil range. T h e notion that crude petroleum i> composed of the members of a few homologous series of hydrocarbons is a valuable concept but one whose attractive simplicity fre«ju:-nt».y leads to underestimation of the chemical complexity of petroleum. Besides the paraffins, mononuclear cycloparaffins, and aromaties occurring naturally in crude petroleum. there are m tue high molecular weight onmpnu.'ids nr-ced cycloparaiïin-aroniaticstriieturi'r* with paraffintc side chains, and i t is apparent that with these possibilities theoretical speculation can b e r e f t bewildering. Petroleum was ascd m a n y years before much information became available on its chemical composition. In recent y canconsiderable work has been done in this field, most outstanding being t h a t under t h e sponsorship of the American P e t r o leum Institute and now being carried out at t h e National Bureau of S t a n d a r d s .

Table I I I .

BartSesville, OkSa., research laboratory of Phillips Petroleum Co.

Initially this work was directed by E. W. Washburn and later by F. D . Rossini (ί). Significant contributions in this field have also been m a d e by M. It. Fenske and co­ workers a t Pennsylvania S t a t e College (6). For a general background on petro­ leum reference is m a d e to (4.) and (9). Considerable progress h a s been m a d e in expanding our knowledge of t h e more vola­ tile constituents of petroleum. In T a b l e III are given the results of t h e investigation by Forziati, Wellingham, Mair, and Rossini (7) of t h e composition of the naturally occurring n a p h t h a s from seven different crudes. Normal paraffins, isoparaffins,

Data on Straight-Run Naphtha Composition

A m o u n t s of i n d i v i d u a l hydrocarbons (paraffins a n d n a p h t h e n e s , 4 0 ° t o 1 0 2 ° C . 104° t o 2 1 5 . 6 ° F., and aromaties to 1 6 0 ° C , 3 2 0 ° F.) in t h e original n a p h t h a (approximate) BOILING POJNT AT 1 ATM., COMPONENT

G

O.

P E R C E N T A G E BY V O L U M E or

Ponca, Okla.

East Texas

Bradford, Pa.

OreendateKawkawlin, Mich.

DISTILLATES, 4 0 °

Wink1er, Texas

το

180°

Mid­ way, Calif.

roe, Texas

C.

Paraffin a n d N a p h t h e n e Cyc'opentane 2,2-Dimethyll>utane 2.3-Γ, nriethylbutane 2-Methylpentane 3-Methylpentane

49. 20 49.74 57.99 60.27 63.28

0.14 0.11 0.23 1.12 1.04

0.28 0 . 17 0.41 2.39 1.82

0.21 0.15 0.43 3.42 2.04

0.24 0.05 0.30 1.34 0.88

0.30 0.23 0.52 1.67 4.18

0.73 0.25 0.30 1 .68 t . 14

0.23 0.19 0.31 1.53 1.07

0.05 0.05 0.05 0.05 0.05

n-Hexane M e t h y l cyclopent a n e 2 , 2 - D i m e t h y l ppe enn1t a n e 2\4-Dimethylpentane Cyclohesane

68.74 71.81 79.20 X 80.51) 80.74

5.39 2.60 0.29 2.13

4.78 3.61 0.91 1.83

5.79 1.38 0.86 1.79

11.24 1.56 0.30 1.99

1.13 1.55 0.83 0.6Ϊ

1.88 3.98

2.36 2.82 0.40 4 13

0.04 0.04

0.45 2.47

0.08 0.06

(2,2,3-Trimethylbutane) (3.3-Dimethylpentane) 1,1 -Dinaethy Icyclopen tane 2,3-Dimethylpentane 2-Methylhexane

80.88 86.06 87.5 89.79 ) 90 0 5 }

o!49 3.23

θ!δδ 3.50

0.53 3.67

036 1.88

0.62 4.4"

0.57 2 . 14

0.43 2 36

0.16 0 20

trans-1,3-Diroethy ley clopen t a n e i r a n e - 1 „ 2 - D i m e t h y Icyclopen Lane 3 - Methylhexane ( 3 - E t h y lpen tane) (cis-l,3-Dimethylcyclopentane)

90.8 91.9 91.9i 93.-Î7 (?)

3.5^ 1.22 O.V.s

3.89 1 50 Ϊ 16

1.50 1.41 1.51

0.68 0.24 0.36

1 54 1.19 3.68

5.21 2.03 0.60

1.48 0.39 C.45

0.25 0.20 0.20

n-Heptane i2,2,4-Trimethylpentane) (cis-l,2-Dimethylcyclopenta.ne) MethyHcyclohexane

98.43 99 . 24 99.3 100. 93

Total

Benzene Toluene Ethylbenzene p-Xylene wi-Xylene .©-Xylene Isopropvlbenzene •n-Propylbenzene Total T o t a l k n o w n composition

346

8 0 . 1ϋ 110.62 136.19 138.35 139.11 144.42 152.40 159 22

7.07

13.17

1.27

0.05

4.86

6.54

5.75

4.10

1.47

5.y5

9.61

34.19

3 8 01

37.51

38.69

25.26

30.56

31 0 6

ο .46 1.53 0 56 0 29 1.53 0.80 0.21 0.24

0.21 1.73 0.68 0.50 1.93 0.88 0.16 0.23

0.19 1.52 0.26 0.50 1.83 0.63 0.10 0 10

0.63 1.77 0.36 0.28 1.20 0.52 0.13 0.14

0.13 0.26 0.23 0.36 0.24 0.09 0.30 0.20

0.20 1.28 0.66 0.44 1.08 0.63 0.26 0.21

1.23 7.37 0.93 1.78 6.10 2.04 0 32 0.42

5.62 3 9 81

6.32 44.33

5.19 42.70

5.03 43.72

1.81 27.07

4.76 35.32

20.19 51.25

0.08

0.03 0.03 0.06 0.06 0.10 0.04 0.03 0 04

C H E M I C A L

a l k y l c y c l o p e n t a n e s , a l k y ley el oh ex a n e s , and aromaties are reported found in t h e n a p h t h a s with the differences from one crude to another being essentially in t h e relative amounts of the foregoing five classes of hydrocarbons. T h e table sug­ gests in compelling fashion the complexity of the problem of the separation of indi­ vidual gasoline hydrocarbon components from crude petroleum. I t also shows sig­ nificantly the possible variation in yield of individual hydrocarbons from crude to crude and hence the potential variation in availability of a hydrocarbon from one refinery to another. T h e picture of availability is further complicated by the differences in refinery operations neces­ sitated by differences in crude source, equipment available, market conditions, and company policies. In the early days of petroleum refining simple distillation was used to effect rough separations of hydrocarbons of different volatilities. T o d a y more precise distilla­ tion methods are available in fractiona­ tion, superfractionation, azeotropic dis­ tillation, and extractive distillation. Crystallization, extraction, and t h e other refining processes can be utilized if oc­ casion d e m a n d s and economic r e t u r n war­ rants. T h e physical basis for t h e possible combination of fractionation a n d crystal­ lization to effect hydrocarbon p r e p a r a t i o n

Table I V . Effect OF" Structural Symmetry on the Freezing Point oi Hydrocarbons BOILING PO 0INT,

O c t a n e i s o m e r s , CaHia 2-Methyl heptane n-Octane Tetramethylbutane n - N o n a c o s a n e , CwHer Xj'lene i s o m e r s , C»Hio m-Xylene o-Xylene p-Xylene

C.

117.2 125.6 iOô.o 295/15 m m . 139.1 144.1 138 3

FREEZING PO 0INT,

C.

-11». 5 7

-

48

+

25 13

as shown in T a b l e IV (16) is t h e effect of structure in spreading the freezing p o i n t of hydrocarbon isomers of approximately t h e same boiling point. As shown, a highly branched octane with only 8 carbon a t o m s can have a higher freezing point t h a n nnonacosane with 29 carbon atoms. A N D

E N G I N E E R I N G

N E W S

While fractionation is a friend of lon^ standing in the petroleum industry, t h e newer distillation techniques arc undergoing rapid industrial development. T y p i cal fractionation operations utilize columns with 20 to 30 plates and a ratio of reflux to overhead products of about 2 to 1. Superfractionation utilizes 100 to 150 plates and reflux ratios u p to 50 to 1. Azeotropic distillation operations will require from 50 to 100 plates depending on the exact system used. Methanol is used to separate toluene from cracked motor fuel fractions {15) and the use of sulfur dioxide in butane-butene separation is reported by Matuszak and Frey (13). Mair, Glasgow, and Rossini {12) discuss in detail the laboratory aspects of the separation of hydrocarbons by azeotropic distillation. Extractive distillation or distillation carried out in the presence of a relatively high boiling polar solvent is exemplified by t h e use of furfural in the purification of butadiene {2, 10. 11). These procedures are powerful tools for the separation of hydrocarbon mixtures, but the newer distillation operations all require more equipment and hence higher capital charges per u n i t of production. T h e development of superfractionation, azeotropic and extractive or absorptive distillation is so new t h a t full scope of their industrial application is not yet realized.

concentration in the n a p h t h a fraction from Ponca City crude as reported by Rossini {17) in Table V. While 7i-deeane is present in 13.6% concentration in the distillate, the concentration is only 1.0% in t h e crude. Thus there is a practical limit t o the amount of a given hydrocarbon which a refiner can supply. T a b l e V also shows the presence of mixed ring or eycloparamn-aromatie structures. I t is axiomatic in anv business run for

to the tremendous quantities processed in a given operation. In addition, most petroleum products are used as fuels or lubricants and in these applications mixtures of different hydrocarbons are permissible. However, the organic chemist in general desires pure materials with which to work because of the simplification in chemical processing and the improved yields. "There are substantial savings in chemical industry in using p u r e hydrocarbons but in practically every instance the

Tabic V . Concentration of Some Kerosene Hydrocarbons in Ponca City Crude VOLUME PER CENT HYDROCARBON

n-Decane 1,2,3,4-Tetramethylbenzene 5,6,7.8-Tetrahydronaphthalene l-Methyl-5,6,7,8-tetrahydronaphthalene 2-Môthyl-5,6,7,8-tetrahydronaphthalene JNapIitbalene 1-Methylnaphthalene 2-Methyinaphthalene Total

In 392-446° F. in distillate crude 13.6 =*= 0.8 1.0 0.078 l) 15

0.020

19.4 «fc 0.8

0.050 0.034 0.062 0.132 1.4

Selective solvent extraction of light fractions is illustrated by t h e commercial Edeieanu process utilizing sulfur dioxide in extraction of aromatics from kerosene fractions (4). Doubtless other applications of this technique to petroleum refining operations can be made after the war. Crystallization and adsorption are tools not y e t applied commercially to light hydrocarbon separation b u t are available for exploitation. T h u s the foundations of a technology h a v e been laid which promise to m a k e available to t h e organic chemical industry a t a price any hydrocarbon found in s t r a i g h t - r u n or cracked n a p h t h a fractions. In further consideration of the economics of hydrocarbon intermediate supply, it should be recognized t h a t a commercially pure material, say 9 5 % or better, is going to be recovered in relatively low yield from the crude. For example, take the case of T^decane occurring in 13.6% V O L U M E

2 3,

Government-owned butadiene plant

0.048

N O .

4

profit t h a t t h e customer pays for any new plant needed to meet his requirements a n d this is particularly applicable t o any new highly specialized p r o d u c t . These hydrocarbon intermediates are highly specialized from a petroleum point of view. T h e problem of investment oharg^e per u n i ι volume of hydrocarbon intermediates b e ­ comes more acute on consideration of t h e great physical disparity in petroleum and chemical processing operations. This can be readily appreciated on comparing t h e physical volume of crude petroleum pro­ duction with the t o t a l volume production of organic chemicals in 1943 as shown in Table VI (5, 14). TebSe VI. Physical Volumes of Organic Chemical and PetroBeum Operations in 1943 Organic chemicals Crude petroleum Motor gasoline Aviation gasoline

Bbl.(42 gal.) per day 78,000 4,500,000 1,500,000 400,000

The phenomenally low unit costs for t h e processing of petroleum are due primarily

F E B R U A R Y

2 5,

1 9 4 5

chemical industry will have to bear the cost of any special purification required. In some cases relatively pure hydrocar­ bons axe available at low prices because the separation is inherently easy or has bee^ -stifled for petroleum purposes and not ίο provide a chemical intermediate. The chemical industry is t h e beneficiary of t h i s fortuitous set of circumstances. \Vhen, however, t h e chemical industry de­ mands a pure hydrocarbon which is not available as such, the price of the hydro­ carbon intermediate goes u p . Any specificatioo on a product increases its price re­ gardless of t h e field of endeavor. Distilled water costs more than sea water. A roercaptam-frce gasoline costs more than a sour gasoline. Any pure product costs more than tiie concentrate from which it comes. Occasionally these differences in cost have been brought to the minimum through large-volume processing, b u t the chemical demartd for hydrocarbon intermediates a t best i s measured in tank car quantities and t h i s is a modest operation by petro­ leum standards. Hence t h e equipment charges for new plants installed to provide 347

intermediate.- will be high relative to or­ d i n a r y refinery costs. It is for these rea sons that it behooves the organic chemist t,o consider well t h e specifications which m u s t he imposed upon a hydrocarbon in­ termediate in order to meet his require­ ments. Frequently a compromise be­ tween hydrocarbon costs and high yield or convenience must be struck if the inter­ mediate price is t o be in the practical range. Petroleum By-Products. In a process sense, a by-product occurs fortuitously a> a result of an operation with another end result as its objective. If a substance i s truly a by-product there can be nospecifiration on it, since otherwise it loses its definitively fortuitous character. Typical properties can be used to describe by-prod­ ucts but no assurance ran be given as to uniformity of product or continuity of sup­ ply if they are to be sold on what is essen­ tially a distress price basis. Any guaran­ tee of continuity of supply by a refiner immediately decreases the flexibility of Jhis own operations at a potential money cost to him. If t h e sale of the so-called by-product on a continuing commitment i s to be attractive, adequate compensation sjiust be made. This is a point of view all t o o frequently disregarded and one which m u s t be kept constantly in mind when considering petroleum as a source of hydro­ carbons for chemical industry. Despite these discouraging remarks with respect to the cost of petroleum hydrocar­ bons, there is a group available a t a low price. These are t h e liquefied petroleum gases which include propane, isobutane, τζ-butane, isopentane, and n-pentane, de­ rived from natural gasoline. The markets for these gases lie largely in the northeast­ e r n United States, in which area the sup­ ply is inadequate to meet the demand, and s o large volumes are brought in from the southwest. Accordingly, the market price structure has been built u p on an f.o.b. Group I I I (southwest) basis, for the reason t h a t any locally produced lique­ fied petroleum gas which is diverted to a chemical use must b e replaced by material brought in from t h e southwest, and the delivered cost t o the customer is the price G r o u p III plus freight. In order to have s common price base for reference it has proved in practice most satisfactory to q u o t e these materials on a Group I I I basis. Propane and butane find large outlets a s premium fuels for heat-treating metals, singeing textiles, a n d for domestic use. rs^Pentane finds outlet as a fuel. Isobutane, isopentane, diisopropyl (δ), and isooctane ©ïe important in t h e manufacture of aviat i o n gasoline. Butadiene is familiar to all as the dominant raw material for synt h e t i c rubber. Isoprene finds a limited use iik the manufacture of Butyl rubber and i o some specialty rubbers. Dicyclopentaciione of approximately 7 0 % concentration is reportée to be available and used in polymerization. T h e present production of toluene, 9 0 % of which comes from pe£48

t roleum, has enabled the Army to use T N T without stint. Ethylbenzene is made, by the alkylation of coal-tar benzene with ethylene from petroleum. It is made primarily for subsequent dehydrogenation to styrene but in recent months much has been diverted to aviation gasoline blending. Styrene is the lesser co-monomer used with butadiene in the manufacture of (iR-S. Oumene or isopropylbenzene is an aviation gasoline ingredient. Mixed isoheptenes is a mixture of olefin polymers averaging 7 carbon atoms per molecule. The n-hexane and η-heptane concentrates are notable for their remarkably narrow boiling ranges. As solvents and in extraction operations they behave as pure com­ pounds and are of value as reaction media, solvents, precipitation agents, and extractants. Many of these materials are in such demand that the supply is now inadequate and so cannot be regarded as satisfactorily •available for all uses. But in general, chemical uses carry sufficient priority to make even most aviation gasoline ingre­ dients available for such use. Table VII lists the commercially available hydrocar­ bons cited above with their estimated com­ mercially available purity and current large uses.

Table Vfil.

H VDROCA.RBON

Commercial Petroleum Hydrocarbons KSTIMATED PURITY AVAILABLE AT A P R I C E , cr /C 99

Literature Cited

P R E S E N T USES' 1

Premium fuel, refinery reagent., H; manufacture ->8 Aviation gasoline Isobutane 99 Premium fuel n-Butanc 95 Aviation gasoline Isopentane 95 Premium fuel H-Pentane 95 Aviation gasoline Diisopropyl Mixture of Aviation gasoline Isoôctane isomers 99 Synthetic rubber Hutatliene 95 Synthetic rubber Isoprene Dicyclopentadiene Approx. 70 Intermediate 99 Explosives Toluene For styrene and 99 Kthylbenzene for a v i a t i o n gasoline 99 Synthetic rubber Styrene 95 Aviation gasoline Cumene Chemical interIsoheptenes Isomeric mediate and in mixture aviation gasoline n-IIexane concen- 4° F. boil- Solvent trate ing range 2° F. boil- Solvent n-Heptune coning range centrate a Not necessaril·y in maximum purity. Propane

Conclusion

It is clear t h a t petroleum offers the organic chemical industry a wealth of new raw materials for organic synthesis. T h e supply of pure hydrocarbons potentially is large. Techniques for their separation are already in commercial use but their development is far from complete. Insistence on high purity increases the cost of the hydrocarbon and tins penalty is greater the higher the average molecular weight, owing to the greater complexity of the mixture from which it is recovered and the increasing processing required to effect the separation. Petroleum byproducts cannot be held uniform in quality and warranted as to continuity of supply and be available on a distress price basis. Any restrictions imposed by the buyer on the seller with respect to either of these points must of necessity increase their price. T o d a y 17 hydrocarbons are being produced and shipped in commercial quantities; all but three are of high commercial purity. Some are naturally occurring hydrocarbon.*·, but m a n y are synthesized to meet the needs of the war aviation gasoline and synthetic rubber programs. While current supply may be tight, in general chemical needs carry sufficient priority to release them for such application. Postwar additional hydrocarbons will be available and the organic chemical industry can write the ticket if it is prepared to pay the price.

(1) Am. Petroleum Inst., Project 6 on composition of petroleum; see Proc. Am. Petroleum Inst., I l l , and Nail. Bur. Stanrlards J. Research from 1927 to date for papers by E. W. Washburn, F . D. Rossini, and associates. (2) Buell and Cooper, U. S. Patent 2,350,584 (June 6, 1944). (3) Chem. & Met. Eng., 51, 96 (1944). (4) Dunstan, A. E., Nash, A. W., Tizard, Henry, and Brooks, B. T., "Science of Petroleum", New York, Oxford University Press, 1938. (5) Evering, B. L., Fragen, N., and Weems, G. S., CHEM. E N Q . N E W S , 22,

(6) (7) (8) (9)

Oth»»r postwar hydrocarbon possibilities are: Propylene, isobutylene, butène-1, butene2, n-hexane, η-heptane, isooctane, and ole­ fin polymers. Propylene, isobutylene, butene-1, and butene-2 will doubtless be available in concentrates but if high purity is required it is almost certain thr.„ their price will be substantial. n-H>-\ane, nheptane, and isoôctane can bo made available at a price. Other olefins and olefin polymers can also be made available, but if tailor-made hydrocarbons are required they will not be cheap. CHEMICAL

(10) (11) (12) (13) (14) (Ιό) (16) (17) A N D

1898-

1902 (1944). Fenske, Quiggle, and co-workers, Ind. Eng. Chem., 1932 to date. Forziati, Wellingham, Mair, and Rossini, Natl. Bur. Stana\irds J. Research, 32, 11 (1944). Grosse and Egloff, "Physical Constants of Paraffin Hydrocarbons", U. O. P. Bull. 219. Gruse and Stevens, "Chemical Technology of Petroleum", New York, McGraw-Hill Book Co., 1942. Hachmuth, U. S. Patent 2,350,609 (June 6, 1944). Holloway and Thurber, Ind. Eng. Chem., 36, 980 (1944). Mair, Glasgow, and Rossini, Nail. Bur. Standards J. Research, 27, 39 (1941). Matuszak and Frey, Ind. Eng. Chem., Anal. Ed., 9, 111 (1937). Merrill, Lynch, Pierce, Fenner, and Beane, New York, "Petroleum", 1944; petroleum industry sources. Oil Gas J., 42, No. 49, 130 (April 13. 1944). Rossini and co-workers. Refiner Natural Gasoline Mfg., 16, No. 11, 545 (1937). Ibid., 20, No. 11, 138 (1941). ENGINEERING

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