This invention relates to the cracking and refining of petroleum oils, and could also be characterized usually as offering an improved system for initially subjecting a suitable charging stock to in depth cracking to produce a high proportion of lighter than gasoline but potential gasoline forming fractions and compounds, and then subjecting these cracked merchandise to polymerization below circumstances productive of an abnormally high yield of recoverable gasoline fractions.
In accordance with the invention, the charging inventory first is subjected to cracking under high temperatures, and ideally under relatively low pressures, for the purpose of inflicting a high degree of dissociation or cracking of heavier than gasoline fractions, and the manufacturing of lighter than gasoline compounds capable of polymerization to kind gasoline fractions of nondetonating qualities. Using the current system 2( it is feasible, due to the effectiveness of the polymerizing stage, to initially topic the hydrocarbons to extra intensive cracking than would usually be fascinating or economical attributable to excessive fastened fuel losses. 2 After the hydrocarbons have been subjected to cracking under such situations, the cracked vapors are polymerized by contact with catalytic materials and beneath high strain that may produce an abnormally excessive degree of polymerization of the vapors in the presence of the catalyst.
Following cracking, and with or without preliminary fractionation or polymerization, the vapors are mechanically compressed to a excessive strain and ideally are subjected to polymerization by contacting them with adsorptive materials, as by passing the vapors by way of a physique of adsorptive clay. Being maintained below excessive stress whereas subjected to the action of the clay, the nonvolatile constituents of the vapors endure a high diploma of polymerization, with resultant and proportionate formation of gasoline fractions.
After polymerization, the vapors could also be additional handled or fractionated by any suitable methodology to condense and separately remove fractions heavier than gasoline, and to lastly condense the product gasoline.
The invention might be understood to finest benefit from the following detailed description of a typical system embodying the invention and illustrated diagrammatically and in move sheet type in the accompanying drawing.
The charging inventory launched to the system through line 10 may include any suitable petroleum hydrocarbon or fraction thereof, able to undergoing cracking in the nonetheless I I to a level such that the desired comparatively excessive yields of polymerizable and potential aromatic and different high octane ranking compounds, shall be formed.
Thus the charging stock could include suitable crude oil or fractions akin to fuel oil, gas oil or kerosene distillate. Additionally the invention contemplates cracking the hydrocarbons in still 1 in both liquid or vapor phases, although on the whole it will likely be most popular to take care of cracking temperatures and pressures on a given hydrocarbon undergoing cracking, such that the cracking reactions will happen no less than largely in vapor section.
In flowing from line 10 through the conventionally illustrated cracking nonetheless I , which could also be of any suitable type and design, the charging inventory undergoes cracking at temperatures which will vary from 900′ to 1300′ F., or above, relying upon the nature and composition of the charging zero inventory, beneath nevertheless comparatively low pressures, for example from substantially atmospheric as much as around 75 lbs. per sq. in. The place in order to obtain the specified degree of cracking in stillI i it may be necessary to crack the hydrocarbons at significantly greater pressures, any desired pressure may be maintained on the oil undergoing cracking, as by a valve 12 within the outlet line thirteen, and the stress then reduced to below say seventy five lbs. per sq. in., beyond the valve.
SThe cracked hydrocarbons are discharged by way of line 13 into an enlarged separating chamber or reaction zone 14 whereby any carbon and unvaporized residue are separated from the vapors and removed from the system via 35 line 15. The cracked vapors leaving chamber 14 by line IS then are subjected to compression and subsequent polymerization, either with or without first being further treated prematurely of the point of compression. As illustrative, the forty vapors may move directly from line 16 by way of line eleven to a compressor or sequence of compressors of a sort tailored to handle high temperature vapors, and conventionally illustrated at 18, or the vapors might first be discharged via line 45 19 for preliminary therapy, polymerization or fractionation by any appropriate means, typified by column 20. Merely as illustrative, this column could include a body of adsorptive materials 21 by means of which the vapors endure preliminary 50 polymerization in flowing upwardly to the outlet 22 connecting with line 17. Then again, column 20 may encompass an abnormal fractionating column within which the heavier ends are condensed out of the vapors. The liquid polymers 55 or condensate, because the case may be, are faraway from the bottom of column 20 through line 23 to 1 recirculated via line 24 for cracking in st I , or discharged to storage by means of line 2 Where column 20 or other related apparatus used, it is preferred to again topic the liqui polymers or condensate to cracking and to retur the cracked products to chamber 14 so as thE from a given charging inventory, a maximum yield c lighter cracked hydrocarbons will likely be produce for conversion in the high stress stage of th system.
卤he comparatively low strain vapors flowin through line 17 to the compressor, are compressei by the latter to a relatively high stress, whic ordinarily will likely be not less than 200 pounds per sq. in larger than the vapor pressure on the inlet sid, of the compressor, ideally to a pressurn of round 400 lbs. to 600 Ibs. per sq. in. gauge Relying upon the characteristics of thg cracked vapors and the kind of catalyst employed within the polymerizing chamber, pressures in excess of these named could also be used in ordei to acquire most levels of polymerization The compressed vapors are discharged from compressor 18 via line 26 to a polymerizing zone shown sometimes as a vertically extending column 27. Preferably, polymerization is no less than in part induced by contacting the vapors with an appropriate adsorptive material reminiscent of fuller’s earth, bauxite, Murock, or Death Valley clays, employed in sufficient quantity to topic the vapors to intimate and prolonged contact therewith. Accordingly, column 27 is proven to contain a physique 28 of such adsorptive materials extending vertically above the purpose of entry of the vapors a substantial distance in order that the vapors have a chronic path of circulation via the clay. One or more of such columns of course may be employed, relying upon the desired time of contact and length of vapor journey by the clay. The polymerizing chamber may contain rather than or along with the adsorptive clay, other catalytic agents capable of selling polymerization of the vapors. For instance the clay body might contain or be impregnated with any of the metals, metallic compounds, and notably metallic salts, recognized to have the property of catalyzing the reactions of polymerization.
In thus being subjected to polymerization une der high stress, a big percentage of the ill larger boiling and normally uncondensible vapor 5. fractions are transformed to condensible hydrois carbons inside the gasoline range. At the identical id time, gum-forming compounds are converted to n heavy liquid polymers which drain to the botit tom of the column 27, from which they may be )f removed from the system through line 29 or crimson circulated by means of line 30 for recracking in nonetheless e 10 I . Polymerized vapors leaving the column through line 31 could also be subjected to any desired g further treatment and method of condensation 1 or fractionation to provide the gasoline product.
S Merely as illustrative, the vapors are shown to .15 be subjected to initial fractionation in column e 32, from the base of which heavy condensed fractions, for example within the fuel oil range, might . be removed to storage by way of strains 33 and 34, Sor recirculated to the cracking still by way of line 35. Leaving fractionating column 32, the vapors circulate via line 36 to the fractionating column 37 whereby heavier than gasoline fractions, resembling hydrocarbons within the kerosene distillate vary, are condensed and faraway from the system through traces 38 and 39, or returned to the cracking nonetheless by way of line forty. The vapors in fractionating column 32 may be subjected to reflux condensation by condensate delivered to the highest of the column from the bottom of fractionating column 37 through line forty one. Cracked gasoline vapors leaving column 37 by means of line forty two move by way of ultimate condenser forty three and the condensed gasoline flows by way of line 44 to receiver forty five. Mounted and uncondensible gases go away the system by way of the valved line forty six.