Патент USA US2407214код для вставки
Patentecl Sept. 10, 1946 2,407,214 UNITED STATES PATENT OFFICE 2,407,214 PRODUCTION OF AN AVIATION OR MOTOR FUEL 0R AN AVIATION OR ll/IOTOR FUEL CONSTITUENT Stanley Francis Birch, Frederick Arnold Fidler, and Leslie Senior Thornes, Sunbury-on Thames, England, assignors to Anglo-Iranian Oil Company Limited, London, England, a British joint-stock corporation No Drawing. Application September 16, 1943, Se rial No. 502,644. In Great Britain July 1, 1942 1 3 Claims. (Cl. 2604-666) The invention relates to the production of 2 cyclopentane from cyclopentadiene andiparticu engine testing unit as against a relative toluene performance of 170 (in the same terms). The larly from the cyclopentadiene present in the so called crude benzol forerunnings of coal tar dis“ physical properties of a representative sample of cyclopentane produced according to the process tillates. In the treatment of these crude benzol iore runnings for the removal of carbon disulphide as, for example, in the treatment with ammonium sulphide for this purpose, the cyclopentadiene is of the invention are as follows: B. P. at 760 mm ___________________ __°C__ Cottrell spread _______________________ __ 20 ' 49.4 Nil - n-D- _________________________________ __ 1.4063 polymerised to dicyclopentadiene and in accord-, 10 ance with invention the latter is then depoly~ d210- __________________________________ -i 0.7456 merised to produce cyclopentadiene again, and Sulphur content _______________ __% wt__ 0.0004 the cyclopentadiene is then hydrogenated to form Octane number (C. F. R. motor method) __ 84 cyclopentane, a substance having an octane num ber of 84 (C. F. R. motor method) and thus 15 According to the invention moreover the crude adapted for use as an aviation or motor fuel or concentrate with its content of dicyclopentadiene constituent thereof, obtained by polymerisation of the crude benzole The invention has among its objects to pro forerunnings with its content of cyclopentadiene, duce cyclopentane under conditions of practical the concentrate having an‘ approximate boiling convenience and e?iciency by the ‘hydrogena 20 range of 75° C.-175° C. is advantageously treated tion of cyclopentadiene, and to avoid the prac e. g. with ammonium sulphidefor removal of tical disadvantages attending the reaction due to carbon disulphide, and thereupon topped to re the considerable amount of heatdeveloped.‘ According to the invention cyclopentadiene is move the light‘ends boiling in the approximate boiling range of 73° C.-80°‘ C. The light ends hydrogenated in the presence of a diluent present ‘ consist mainly of benzene with some unsaturated in such considerable proportion as to avoid the hydrocarbons and sulphur compounds, for ex ample thiophen. The residue after removal of the light ends consists chie?y of dicyclopenta practical disadvantages usually attending the re action by reason of the considerable heat evolved under usual reaction conditions, the diluent func tioning as a moderating or stabilizing agent. Thus according to the invention high concen ‘ trations of hydrogen may be used as a moderat diene by reason of the ease with which such cyclopentadiene in the benzole iorerunnings is polymerised. The cyclopentadiene in the crude forerunnings may however be polymerised rap ing or stabilising diluent in considerable excess idly and successfully to dicyclopentadiene by of the small proportion that is consumed in the contact with‘dilute acid. a reaction; or instead of or in addition to high 35 The dicyclopentadiene may be obtained in a concentrations of hydrogen, benzol or the light pure state by fractionation under vacuum in an ends of the benzol iorerunnings may be used as e?icient column. The material is a solid in the the diluent, or alternatively or in addition the form of colourless needle crystals at ordinary cyclopentane product of the process may be so temperature and has a boiling point of 88.7“ C. at used. The use of the light ends as the diluent 50 mm. pressure. has moreover the further advantage that its con According to the invention moreover dicyclo tent of benzene is re?ned in the process becom ing thereby free from sulphur. The cyclopentane produced under the condi pentadiene may be de-polymerised at tempera ture of l55-170° C. which may be carried out tions described is particularly pure and gives 45 in a column packed with ironturnings or similar material of iron or steel functioning as a catalyst excellent performance as a fuel in a standard and the overhead product taken off slowly at a air-cooled aero-engine testing unit. This is in column head temperature of 40° C.—42° C. The dicated by comparison of the relative cyclopen overhead product of distillation and de-poly tane performance of 240 (in terms of lbs. per square inch B. M. E. P.) in a standard aero 50 merisation is cyclopentadiene and is substan 2,407,214 or 4 tially sulphur-free. By suitable control of the distillation the rate of production of cyclopen an appreciable quantity of solid residue being left tadienev may be adjusted to the rate of hydro genation in the hydrogenation units to which it passes. By such means intermediate storage and re-polymerisation to the dimeride are avoided. The invention comprises the processing condi tions hereinafter described. In carrying the invention into effect the cyclo in the still. This residue may even amount to four times the amount of the residue remaining after vacuum distillation of crude dicyclopentadi ene. The production of these higher polymers we have found may be reduced appreciably by supplying the dicyclopentadiene to the depoly meriser substantially at the rate at which de polymerisation is required and that the de-pcly pentadiene may advantageously be hydrogenated 10 meriser itself should be no larger than is neces in the vapour phase over a hydrogenation-dehy drogenation catalyst of the molybdenum oxide alumina type, and under the following condi-v tions: Temperature ________________________ __ 400° C. Pressure ______________________ __ 200 lbs/sq. in. Oil input rate (total oil feed) _1.0 volumes/volume of catalyst/hour. Hydrogen recycle rate _____ __ 5000-6000 C. F./B. of oil feed. The feed is advantageously diluted with an in ert material in such a proportion as to moderate or stabilise the reaction conditions. The presence of sulphur has however no deleterious effect on sary for this purpose. In this way prolonged heating in the still is avoided. It is known moreover that the polymerisation of the dicyclopentadiene is offset by packing the still with steel turnings or steel wool, whereby a large surface area of iron is thus provided which serves as a depolymerising catalyst. Alternatively under the conditions indicated, the crude concentrate in the state of vapour and without preliminary removal of the light ends may be fed to a de-polymeriser consisting of a vessel packed with iron or steel wool or other convenient packing offering a large surface, and maintained at a temperature for example of 200° C.-300° C. and at a moderate pressure. The vapour leaving the depolymeriser may be con densed and fed to the hydrogenation unit as liq uid, or the vapour may be mixed with hydrogen ends may conveniently be used as a moderating and passed together in vapour phase directly into or stabilising diluent. Under these conditions the further advantage results that the benzene is 30 a vessel containing an hydrogenation catalyst such as molybdenum oxide-alumina. This re?ned in the same operation and the complete method of operation has the advantage that the preliminary removal of carbon disulphide is benzene diluent is already present in the vapour thereby rendered unnecessary. and that no further dilution may be necessary. Alternatively cyclopentane, either as produced Advantageous process conditions are indicated in the process described or derived from another the molybdenum oxide-alumina hydrogenation catalyst and thus the previously removed light source may be used as the moderating or stabilis~ ing diluent. No limitation is involved to the use of the type in the following examples: Example 1.—The light ends with their content of benzene was distilled from 388 liters of the crude concentrate resulting from polymerisation of hydrogenation catalyst indicated. Thus the process may be carried out in the liquid phase in 40 of benzol forerunnings. The greater part came over at atmospheric pressure, but in order to the use of a nickel catalyst at a temperature of avoid overheating in the still and depolymerisa from 50° C.-100° C. If Raney nickel however be tion of dicyclopentadiene at this stage, the last used as the catalyst or any other catalyst liable traces were removed under vacuum at a temper to sulphur poisoning under the reaction condi tions, it is necessary in order to avoid poisoning 45 ature below the depolymerising temperature. The sulphur content of the light ends recovered of the catalyst that the material processed should as overhead was 0.102 per cent by weight, the ?rst be rendered sulphur-free. In such a case original charge of concentrate was 388 litres and cyclopentane itself is a particularly advantageous the light ends taken overhead to 120° C.-208 litres. moderating or stabilising diluent, and thus if it The residue consisting chiefly of dicyclopenta be desired to obtain a pure cyclopentane, cyclo diene was then heated to 160° C.—180° C. at at pentane itself may advantageously be used as mospheric pressure when cyclopentadiene dis diluent in preference to benzene, whereby the tilled off at 2.3 litres per hour. necessity of subsequent distillation to separate The following were the physical properties of the benzene diluent is avoided. The use of benzene has however substantial the cyclopentadiene produced: advantages as a diluent inasmuch as on its dis charge from the process it is substantially free from sulphur as well as frome ole?nes, although it contains a small percentage (approximately 5%) of high boiling residue, probably derived B. P. at 760 In. In ___________________ __°C__ 40.3 n23 ___________ ___ _____________________ __ 1.4450 20 11-4- __________________________________ __ 0.8044 from dicyclopentadiene. In this way the cyclo pentadiene is hydrogenated and the benzene is re?ned in one operation. Furthermore where the The cyclopentadiene was diluted with four ultimate object is to produce an aviation spirit times its volume of the light ends and this total blending constituent the mixture of benzene and 65 oil feed passed over a 5% molybdenum oxide-on cyclopentane after removal of the high boiling alumina catalyst at a temperature of 400° C., and residue may together serve as an aviation fuel a hydrogen pressure of 200 lbs/sq. in. The total constituent without further treatment, the ben oil feed over the catalyst was 1.0 v./v./hr. When zene being restricted to the permitted proporion a sufficient quantity of the hydrogenated product that may be required by the speci?cation. The had been collected, this was used as a diluent for conditions of hydrogenation referred to are such subsequent hydrogenations, the cyclopentadiene that the benzene is not itself hydrogenated. content of the feed to the hydrogenation unit al We have found that during de-polymerisation ways being maintained at 20% by volume. By a considerable amount of the dicyclopentadiene. appears to be further polymerised, resulting in 75 constantly recycling the products, the cyclopen 2,407,214 5 tane content of the ?nal material was approxi- late, comprising the steps of subjecting the fore‘ mately 60% by volume. runnings to polymerisation, and producing a con centrate having an approximate boiling range of 75° to 175° C., distilling the said concentrate for the separation as overhead of the light ends boil Litres Cyclopentadiene produced _______________ __ 99 Hydrogenation products _________________ __ 157 Cyclopentan'e produced __________________ __ 94 Re?ned benzol ___________________________ __ ing approximately at 78° to 80° C., consisting of benzene mainly, together with some unsaturated 63 and sulphur compounds, and a residue fraction The benzol during the processing was desul as bottoms containing dicyclopentadiene, subject phurised (sulphur content 0.0007 per cent by 10 ing said residue fraction to a depolymerising oper weight), and contained approximately 5% of high boiling residue. ation to convert dicyclopentadiene in said fraction to cyclopentadiene, and directly subjecting cyclo Example 2.--The crude material was dropped pentadiene so obtained to hydrogenation in ‘the into a flask maintained in an oil bath at 240° C. presence of a temperature moderating and reac 250° C. By this means the light ends and dicyclo; pentadiene were flashed off from a small amount 15' tion stabilising diluent, to yield the cyclopentane product, said depolymerising operation being car of gummy residue. The vapours from this ?ask were passed through an iron tube of 56" in length, ried'out in a column packed with iron or steel in a divided state such as small pieces or ?bre to and an internal diameter of 11/2", and the tube yield substantially sulphur-free cyclopentadiene was packed with steel wool. The tube was‘ elec trically wound and the products were passed 20 as overhead at a column head temperature of 40° through a water-cooled condenser into a flask to 42° C. at a rate corresponding to the required feed rate of the cyclopentadiene in its hydrogena fitted with a solid CO2 trap. The material was tion. passed through the tube at two di?erent temper atures and at di?erent rates. The following table 2. A process for the production of cyclopentane gives the properties of the original material and from the benzol forerunnlngs of a coal tar distil the various products obtained: late, comprising the steps of subjecting the fore runnings to polymerisation, and producing a con Table centrate having an’ approximate boiling range of 75° to 175° C., distilling the said concentrate for Origi na mate_ rial Run 1 Run 2 Run 3 30 the separation as overhead of the light ends boil Run 4 ing approximately at 78° to 80° C., consisting of benzene mainly, together with some unsaturated and sulphur compounds, and a residue fraction as Conditions bottoms containing dicyclopentadiene, subjecting Temp. of tube ____ __°O.. ...... __ 210 290e300 290-300 290-300 said residue fraction to a depolymerising opera Rate of addition of con centrate. __. _ . .cc./hr_ _ ______ _ . 93 74 141 233 0. 186 0. 148 0. 282 0. 466 0. 8845 0. 8400 0. 8400 0.8380 56 46 47 47 Vol. of concentrate/v01. tion to convert dicyclopentadiene in said fraction to cyclopentadiene, and subjecting cyclopenta ‘ of tube/hour _________________ _ _ diene so obtained to hydrogenation in the pres ence of a temperature moderating and reaction Properties of product Sp. gr. 60° F _______ -- 0.9150 I. B. P. ‘’ C ........... __ 75.5 __ . . . __________ __ 79. 0 64 53 52. 5 52. 5 81. 0 84. 0 88.0 92. 5 98. 0 109. 5 153. 0 166. 5 66. 5 68. 5 72 76. 5 81. 5 87 94. 5 120 54. 5 55. 5 57. 5 59. 5 62. 5 66 70 75 54 55 57 59 62 65. 5 70 75 54 55 56. 5 58. 5 45 61 64. 5 69 74. 5 167. 5 167 I 80 80. 5 80 170.0 170 91 90. 5 88. 5 174. 5 176 173. 5 175 175. 5 212 221 252 249 260 Bromine number Fran cis) __________ __(_____ -_ stabilising diluent, to yield the cyclopentane prod uct, said hydrogenation of the cyclopentadiene 50 product being carried out in the use of a molybde num oxide-alumina type of catalyst at a temper ature of the order of 400° C., at a pressure of the order of 200 lbs. per square inch, at an input rate of the order of 1.0 volume/volume of catalyst/ hour in the’ presence of hydrogen in substantial excess of the proportion taking part in the reac tion. , " 3. A process for the hydrogenation of cyclopen tadiene for the production of cyclopentane, com prising diluting the cyclopentadiene with not sub stantially less than four times its volume of an 726 g. of the product from run 4 was distilled, and the yield of cyclopentadiene was found to be 271 g., or 38 per cent by weight. This indicated 55 inert diluent material to serve as a reaction tem perature moderating and reaction stabilising dil that almost complete de-polymerisation had oc uent and carrying out the hydrogenation reaction curred, since the dioyclopentadiene content of the in the use of a molybdenum oxide-alumina type starting material was 39 per cent by weight. The of catalyst at a temperature of the order of 400° mixture so obtained was fed as before to a hydro genation unit, and the products were cyclopen 60 C., at a pressure of the order of 200 lbs. per square inch, at an input rate of the order of 1.0 Volume/ tane and re?ned benzol. 7 ~ ‘ volume of catalyst/hour and in the presence of a It will be seen from the table that 210° C. is not quantity of hydrogen inthe proportion of at least a sui?ciently high temperature to effect complete de-polymerisation under the conditions indicated, but the reaction was complete at all rates of ad dition used at 290° C.-300° C. ' We claim: . 1. A process for the production of cyclopentane from the benzol forerunnings of a coal tar distil 05 5000 cubic feet of hydrogen per barrel of feed, to yield the cyclopentane product. STANLEY FRANCIS BIRCH. FREDERICK ARNOLD FIDLER. LESLIE SENIOR THORNES.