US1853671A - Petroleum refining - Google Patents

Description

Original Filed Aug. l5, 1928 Y ,Illa '5,5531

a saullllllllllllllgg n Patented Apr. 12, 1932v EDWIN A. DICKINSON, OF EAST ORANGE,

PROCESSES CORPORATION, OF NEWARK,

WARE

NEW JERSEY, ASSIGNOR TO THE GRAY NEW JERSEY, A. CORPORATION OF DELA- PETROLEUM REFINING Application led August 15, 1928, Serial No. 299,777. Renewed February 4, 1931.

This invention relates to petroleum refining and particularly to the treatment of cracked petroleum products in vapor phase with solid adsorptive materials and has for an object an improvement in the method of refining cracked petroleum products by .such treatment. u

It is Well known that cracked petroleum products intended for use as motor fuel must e treated or refined in order to eliminate certain deleterious constituents thereof before Asuch cracked petroleum products are suited for use. One method of effecting this treatment is to pass the cracked petroleum products in vapor phase into contact with a solid adsorptive catalyst which has the property of selectively polymerizing the `less stable hydrocarbons present. The .polymers thus formed are separated from the remaining vapors by virtue of their higher boiling points and are removed as liquids while the refined vapor is collected and condensed in the conventional manner. The reaction of polymerization is exothermic and, as a result, the

treated vapor higher temperature than that of the entering vapor. The temperature rise is most marked when the catalyst is fresh and usually dimin- 4 ishes during the course of a run, although the refining of the vapor continues.

ln some cases the rise in temperature of the vapor during treatment is accompanied by an increase in its final boiling point. Thus, in some cases, gasoline vapor having a inal boil ing point of 437 before treatment has been so modi-ed during the treating process that .its final boiling point is li60" or even higher during the period immediately following the introduction of fresh adsorptive material into the treatin tower. The" gasoline produced during t is period which sometimes lasts for 48 hours, is diiiicult to market and is usually blended with gasoline of lower final boiling point which results in an obvious economic waste.

4The improved method of refining which is the object of'this invention eliminates the temperature rise above referred to and re- 50 suits in a product having its nal boiling often leaves the tower at apoint substantially the same as that of the vapor priorv to treatment.

There seems to be no entirely satisfactory explanation from the theoretical standpoint of the increase in the final boiling point of the treated product. It seems, however, in some way to be connected with the exothermic .reaction and with the increased temperature of the treated vapor and may be due to the failure of the polymers produced tol condense completely at the higher temperature. Whatever thc cause may be, I have found that the rise in final boiling point can be prevented by introducing into the treating tower during the initial period referred to', a liquid, preferably previously treated distillate of approximately the same boiling range as the desired product. This may diminish the intensity of the exothermic reaction or it may simply reduce by heat transfer the amount of temperature increase without in any way effecting the intensity of the reaction itself. However, in whatever way it acts, it accomplishes the desired result.

Other objects, novel features, and advantages of this invention will be apparent from the following specification and accompanying drawings wherein Figure 1 discloses one form of apparatus for carrying out the process and Figure 2 discloses an apparatus for carrying out the process in a slightly modified manner.`

rIhe treating tower 10 is provided with a layer 11 of heat insulating material' and with a fluid permeable shelf 12 which supports bed 13 of solid adsorptive catalytlc material. Vapor to be treated is introduced into the tower 10 through the inlet 14 and treated vapor yis removed through the outlet 15. Polymers and other liquid material produced in the tower are collected in the bottom thereof and are drawn off through the trapped outlet 16. In the top of the tower 10 there are provided a plurality of nozzles 17 connected through valves 18 with a pipe 19. By means of the pipe 19 liquid may be introduced into the tower' through the-nozzles 17, the dow being controlled by means of the valves 18.

After the tower has been charged with the solid adsorptive material 13, such for example as fullers earth, the cracked vapor to be treated is introduced through the inlet 14 and caused to pass through the treating material. rl`he action of the fullers earth on such vapor is to polymerize unstable, unsaturated constituents into higher boiling substances which normally condense and are drawn out through the outlet 16. They may then be returned to a part of the cracking system or removed and handled separately.

The refined vapor leaves the treating tower through the outlet 15 and may be collected and condensed in the usual manner. lVhen the catalytic material is fresh the presence of a considerable exothermic reaction may be noted by thermometers above and below the catalyst of which the latter will have the higher reading. During this period the condensed treated product has a higher final boiling point than the entering vapor. If, as soon as the issuing vapor is found to have a higher temperature than the entering vapor, suiicient liquid be introduced through the nozzles 17 to cause the bottom temperature to approach that of the entering vapor, the increase in nal boiling point is checked. I prefer, for this purpose, to use a product refined in previous operations although other liquids, particularly other hydrocarbons, may be used with satisfactory results.

It is, of course, apparent that high boiling liquid so used will remain liquid whereas low boiling liquid will be vaporized, but in any event, the liquid introduced takes up heat from the vapor undergoing treatment. As an example, the following instance may be cited In a treating tower directly connected with a cracking unit, a fresh charge of fullers earth ordinarily results in a final boiling point of the treated vapors of 450, while that of the incoming vapor is 410. This condition customarily lasts approximately 58 hours in the particular apparatus referred to, and is accompanied by a temperature, rise of 10 in the vapor during treatment. Vapor was introduced intothe treating tower at a rate corresponding to 12 barrels of liquid per hour and to overcome the temperature increase during the first-48 hours of the run 80 gallons of condensed gasoline were sprayed per hour into the top of the treating tower. This cut down the temperature of the issuing vapor and also caused the nal boiling point of the product to be reduced to that of the incoming vapor.

In Figure 2 there is disclosed a similar treating tower 10 having an insulating covering 11 and a fluid permeable shelf 12 upon which is supported a bed of catalytic material 13. The vapor inlet is designated 14 and the vapor outlet 15, while the liquid outlet is designated 16. In the top of the tower 11 there is provided a coil 20, having inlet and outlet pipes 2l and 22 respectively controlled by valves 23 and 24. By passing a coiling iuid `or liquid through a coil 20, the portion of the vapor in the tower 10 may be condensed to provide a liquid for effecting the reduction in temperature of the treated vapor as described in connection with Fig. 1. The liquid thus provided acts in the same way as the liquid introduced through nozzles 17 and has the advantage that it is produced within the tower and to a certain extent simplifies the operation.

The cracked petroleum products may be supplied directly from the cracking operation while still in vapor phase to the refining operation or cracked petroleum products obtained from the cracln'ng operation may first be condensed and then subsequently revaporized for the refining operation. The claims are intended to cover refining cracked petroleum products irrespective Vof whether the vapor of such products is passed directly from the cracking operation to the refining operation without'condensation or whether the vapor is obtained by re-run distillation of cracked petroleum products after condensation. J

It is of course understood that various modifications may be made'in the process above described, without in any way departing from the spirit of the invention as defined in the appended claims.

I claim 1. In the process of refining cracked petroleum products by contact in vapor phase with solid adsorptive polymerizing material and wherein, during a period when the adsorptive polymerizing material is fresh, the issuing vapor normally is of higher boiling range than the entering vapor, the step which comprises passing liquid hydrocarbons with the vapor through said polymerizing material during such period and regulating the supply of liquid hydrocarbons to maintain the boiling range of the issuing vapor substantially the same as that of the entering vapor. p

2. In the process o f refined cracked petroleum products by contact in vapor phase with solid adsorptive polymerizing material and wherein, during a. period when the adsorptive polymerizing material is fresh, the issuing vapor normally is of higher temperature than the entering vapor, the step which comprises mixing liquid hydrocarbons with the vapor to be treated, passing the mixture through the adsorptive polymerizing material during such period and regulating the supply of liquid hydrocarbons to maintain the issuing vapor at a temperature only slightly, if any, in excess of the entering vapor.

3. In the process of refined. cracked petroleum products by contact in vapor phase with wherein the reaction is excessively exothermic stantially when the adsorptive polymerizing material is fresh, the step which comprises adding to the vapor under treatment liquid hydrocarbons during the period that the reaction is excessively exothermic and regulating the supply of liquid hydrocarbons to maintain the boiling range of the issuing vapor subthe same as the entering vapor.

4. In the process o refining cracked petroleum products by contact in vapor phase with solid adsorptive polymerizing material and wherein the reaction is excessively exothermic when the adsorptive polymerizing material is fresh, the step which comprises passing condensate of the vapor through the adsorptive polymerizing material with the vapor during the period that otherniic and'regulating the supply of condensate to maintain the issuing vapor at a temperature only slightly, if any, in excess of the entering Vapor. v

In testimony whereof, I have signed my name to this specification.

EDWIN A. DICKINSON.

the reaction is excessively ex-

Images