US2976422A - Apparatus for irradiating chemical reactions - Google Patents

Description

March 21, 1961 M. w. HILL ETAL 2,976,422

APPARATUS FOR IRRADIATING CHEMICAL REACTIONS Filed July 20. 1953 GRADE l5 [SEWER f \L.INING MAX INVENTORS JAMES F BLACK BY LF- h ATTORNEY United States PatentO APPARATUS FOR IRRADIATING CHEIVIICAL REACTIONS Max W. Hill, Du Quoin, 111., and James F. Black, Roselle,

N..F., assignors to Esso Research and Engineering Company, a corporation of Delaware Filed July 20, 1953, $61. No. 368,972

Claims. c1. 250-405 The present invention relates to improvements in carrying out chemical reactions. More particularly, the in vention is concerned with the activation or promotion of chemical reactions by nuclear radiation. In brief compass, the invention pertains to an improved method of carrying out chemical reactions by exposing the reagents to radiation emitted by radioactive materials, particularly the radioactive fission products obtained as ay-products or waste materials in the operation of atomic piles for the production of atomic energy.

In the operation of atomic piles large amounts of radioactive by-products or waste materials are obtained. Aside from very minor quantities used in medical research and therapy and for various tracer techniques in industrial research and manufacturing processes, no large scale practical application has been found as yet for this quantity of radiation which is available at relatively high intensity levels. In addition, these highly radioactive waste materials cannot be readily discarded without danger to animal and vegetable life. Their steady accumulation presents a disposal problem. The present invention greatly alleviates the difficulty of the problem and affords various additional advantages as will appear from the subsequent description of the invention wherein reference will be made to the accompanying drawing, the single figure of which is a schematical illustration of means suitable for carrying out a specific embodiment of the invention- It has now been found that chemical reactions which require an energy input or activation either for their initiation or maintenance as well as many spontaneous reactions may be promoted by exposing the reactants to radiation emitted by radioactive materials. In accordance with the preferred embodiment of the invention the reagents of such reactions are exposed prior to and/or during the desired reaction to radiation emitted by the fission by-products of processes generating atomic power and/ or fissionable materials.

These by-products include elements with atomic numbers ranging from 30 (zinc) to 63 (europium). The waste materials are formed in the course of converting uranium, thorium or other fissionable material in an atomic reactor. Other radioactive materials, such as naturally occurring radioactive materials, primary fissionable materials and various materials made radioactive by exposure to neutron radiation, such as radioactive cobalt (C0 europium 152, or europiurn 154, etc., may also be used for the purposes of the invention.

Another important embodiment of the invention resides in its application to chain reactions which involve the production of free radicals. This production of free radicals is activated by radioactive radiation in accordf 'ancgwith the invention. When such chain reactions are desired between reactants which are not of the type which readily produce free radicals under the influence of ionizing radiation, the present invention provides for the incorporation into the reaction mixture of small amounts, for example, up to by weight, preferably less than 5% by weight, of compounds which readily decompose to form free radicals. Examples of compounds of this type are alcohols, aldehydes, metal alkyls, organic acids, etc.

A highly desirable modification of the invention which is particularly suitable for promoting the chemical reactions herein described simultaneously afiords a convenient means for storing large quantities of high activity radioactive elements in a condition in which they present no radiation hazard but can be readily utilized in irradiating reaction mixtures on an industrial scale. In accordance with this modification and as shown in the drawing, the radioactive materials are stored in the bottom of a concrete or metal-lined pit 1 which is filled with water to a level 3 sufficient to absorb the radiation being emitted. The radioactive materials 5 may be sealed in metal containers or under a thin layer of concrete 7 so that the water will be protected from contamination by direct contact with the radioactive materials.

For conducting continuous processes in the presence of nuclear radiation, pipes 9 may be lowered into the pit within effective reach of the radiation emitted by the radioactive materials and the reactants for the process may be passed through these pipes. For batch processes, containers 11 holding the reactants may be lowered into the pit in a position where they are exposed to the radiation.

The manipulation of containers and other equipment within this pit may be observed with safety by personnel on the surface since the water acts as a shield for the nuclear radiation. Since earth is a more efiicient shield than water, no radiation will pass through the ground around the pit.

Since cs, 5 and 1' radiation do not produce secondary radioactivity, water of high transparency can be maintained in the pit by a slow circulation of fresh water supplied to the pit through pipe 13 and withdrawn through an overflow 15 into the sewer 17. A gentle agitation of the water by a stirrer 19 or the like so as to bring all of itoccasionally into the zone of intense radiation prevents the pollution of the water by aquatic algae and bacteria.

The shielding requirements for point sources of radioactivity are presented in the table below. For radioactivity which is not concentrated in a point source but is spread out in a line or over an area, additional shielding is required. These calculations show, however, that 15-20 ft. of water provide adequate shielding for any quantity of radiation that might conceivably be required.

Shielding thickness for I Inn/hour at 1 foot from shield 1 Inches of Shield Required For- Quantity of Radioactive Cobalt (Ourles) Lead Iron Concrete Water l Permissible exposure is 50 inn/day.

The above table also shows that the water shield may be replaced by relatively thin lead, iron or concrete shields.

Numerous chemical reactions and industrial processes involving such reactions may be carried out in equipment of the type illustrated in the drawing using radiation intensities within the broad scope of, say about 10,000- 20,000,000 Roentgen/hr. and radiation times of a few seconds to several hours, usually about 05-24 hrs. Several examples of such reactions are given below. However, the application of this invention to these reactions is of unsaturated hydrocarbons.

not limited to the use of a system of the type illustrated in the drawing. Other suitable means for exposing the reactants to radiation of radioactive materials without presenting problems of disposal and danger to operating personnel may appear to those skilled in the art.

Hydrocarbons or hydrocarbon mixtures, such as various petroleum fractions, may be subjected to various reactions for inter-molecular changes by exposure to radiation emitted from radioactive materials. Such reactions are, for exarnple, cracking, reforming, hydrogenating, polymerizing and -a1kylating. For cracking to products of lower molecular weight, conditions of temperature, pres sure and residence times are preferably so chosen that the cracking products of the process are volatilized and continuously removed from the further effects of radiation. Gas oils, including cycle stocks from other cracking processes, thermal or catalytic, and other high boiling petroleum fractions, such as residual stocks and asphalts may thus be cracked to produce valuable lower boiling hydrocarbons, such as distillates, naphthas, motor fuels, unsaturated hydrocarbons, etc. Coke formation in this process is substantially less than in thermal cracking processes. Conditions suitable for this purpose include temperature of 100'800 F., radiation intensities of 50,000

to 5,000,000 Roentgen/hr., and pressures of 5-250 lbs./ sq. in. abs.

Naphthas may be reformed by exposure to intense radia tion from large quantities of radioactive materials, such as fission by-product at 50-750 F., 50,000-5,000,000' Roentgen/hr. and 5 -250 lbs/sq. in. abs.

This radiation results in isomerization and/ or aromatization of the naphtha, V Dehydrog'enation and cracking also take place.

The process produces a naphtha with higher octane number than that of the feed stock. Temperatures and pres sures as high as are needed in conventional catalytic or thermal reforming processes are not required for this process. In fact, low temperatures, i.e. below 500 F.,

and short contact times, less than 1 hour, favor the production of a larger proportion of cracking or dehydrogenation products than of polymerization and/ or hydrogena tion products.

Similar advantages are obtained in the hydrogenation The process may be carried out in accordance with the invention by subjecting mixtures of unsaturated hydrocarbons, of a wide range of molecular weight, and hydrogen to the influence of nuclear radiation emitted by'fission products or other radio- Catalysts are not usually needed in this process, although they active materials of suitable radiation intensity.

may be used, and temperatures and pressures substantially lower than those required in catalytic hydrogenation may be used. Temperatures of about -50500 F. and pressures of about 1-50 atm. are generally adequate at radiation intensities of 50,000-5,000,000 Roentgen/hr.

CO may be added to compounds with which it will not usually react without catalysis by exposing a mixture of CO and H with the organic compound to intense radiation from a large quantity of radioactive material, such as fission by-product. For example, aldehydes may be produced from olefins by contacting CO and H with olefins under the influence of nuclear radiation avoiding the requirement of cobalt catalyst separation which greatly complicates the conventional catalytic oxonation.

Particular advantages are afforded in connection with such reactions which normally require extreme conditions of temperature and pressure as well as the (use of catalysts. An outstanding example of such reactions is the fixation of nitrogen. When mixtures of N and H; are irradiated using a large quantity of fission by-products, ammonia is produced at 0300 F. and without the use of catalysts.

In other polymerization reactions, hydrocarbon mixtures or pure hydrocarbons are exposed in the vapor state to radiation from radioactive elements at l00+400 F. This exposure may be carried out in a vessel in which into subterranean strata or geological formations which the higher molecular weight hydrocarbons formed by the reaction are condensed or adsorbed in a zone in which they are removed from the eflects or further radioactive bombardment. This may be accomplished by placing the condensing or adsorbing zone below the reacting zone, so that the relatively heavy reaction products drop out from the vapors into a position in which they are shielded from the radiation and from which they can be removed continuously by any suitable means, as will be obvious to those skilled in the art.

Similarly, paraffins and isoparaflins are polymerized, with concurrent dehydrogenation, to useful products by irradiating with radioactive materials, e.g.

irradiation These reactions proceed at temperatures up to 300 F. or higher.

Valuable polymerization products of the motor fuel range are obtained when low molecular weight olefins, particularly isobutylene are polymerized by irradiating with radioactive waste materials or radioactive cobalt at -l00-+400 F. and 5x10 to 5X10 Roentgen/hr. All the radioactivated polymerization processes have the advantage over previous processes that the product is not contaminated by polymerization catalyst and does not require catalyst removal.

Alkylation reactions represent a further highly important field of application for the present invention. For example, aromatics such as benzene, naphthalene, anthracene, etc. and substituted aromatics such as phenols, aniline, chloro-, alky-land nitro-aromatics may be alkylated by contacting with alcohols, olefins, and alkyl chlorides while irradiating with radioactive materials at about 70-350 F. Also mixtures of olefins and isoparaflins when irradiated by radioactive materials at about -60- 350 F. form valuable alkylation products, such as high octane motor fuels.

The activating energy of radioactive radiation may also be employed in a special application of cracking and polymerization reactions to facilitate and improve the recovery of crude oil and the utilization of natural gas. For the former purpose, high concentrations of radioactive fission products are pumped into an oil field through injection wells. This operation is similar to and may be run concurrently with water flooding operations. Un derground, the radiation from the injected fission products cracks those remaining portions of crude petroleum which were not recovered in primary production from the oil field. The cracked products are more fluid than the original indigenous hydrocarbons and are, therefore, more easily flushed from the formation by water flooding or gas pressuring. The oil recovery is, therefore, larger than that resulting from simple water flooding or similar techniques.

Although the fission products are by-product materials from atomic energy plants and are not expensive, their recovery in part is desirable. This is possible by pumping them out from production wells after the recovery operation is completed. These recovered materials may be pumped back into the field at positions closer to the front of the flood. If left in the formation, they assist in solving part of the disposal problem which is confronting atomic power plants with respect to their radioactive waste products.

Inaccordance with the second of the two purposes mentioned above, radioactive fission products are pumped -arefbein'g used for the underground storage of natural gas or in which there arenaturally occurring gas deposits.

Over a suitably long. period of time the radiation from the radioactive materials converts the hydrocarbon gas by consecutive or concurrent cracking and polymerization into a mixture of higher molecular weight liquefiable or liquid petroleum products. The liquid petroleum products may be recovered as crude oil or as naphtha or gasoline, after separation from any hydrogen formed during the reaction underground. The hydrogen can be recovered separately and used as fuel or for conversion to other useful products, e.g. ammonia.

The invention is well adapted for halogenation, such as chlorination, of various hydrocarbons either as pure compounds or as complex mixtures. The chlorination is effected by exposing a mixture of chlorine and a pure hydrocarbon or a hydrocarbon mixture to the radiation from a large quantity, corresponding to, say, about 50-5,000 curies, of radioactive material at about 0"- 300 F. The chlorinated product may be condensed continuously from the reaction mixture if a vapor phase reaction is employed as it may be removed by distillation if a liquid phase operation is carried out. Fission products formed as the by-product of atomic piles or artificial radioisotopes such as cobalt are the preferred source of inexpensive radioactive material for this process. The chlorinated hydrocarbons which can be produced include all molecular weight ranges from methyl chloride to chlorinated wax. Dior polychlorinated hydrocarbons may be produced by a proper choice of the proportions of reacting chlorine. Also, fiuorination reactions may be carried out in a generally analogous manner. Thus, acids, amines, parafiins, etc. are fiuorinated by mixing with HF and irradiating with radioactive materials at about -40"- 300 F.-, as illustrated by the equation radioactive C Hs-O 0 O H+3HF radiation In a similar manner tertiary alkyl, aryl and mixed alkyl-aryl hydrocarbons may be irradiated in the presence of oxygen at low temperatures of about 100-+40 F. to form valuable peroxides as illustrated by the fol- The final product may be decomposed to phenol and acetone by exposure to further bombardment or conventional thermal and/or catalytic treatment.

Combustion processes also may be aided by the process of the invention. More complete and more efficient combustion of all types of fuels with greater heat output per unit volume and less smoke and stack solids is produced by conducting the combustion in the presence of a high intensity of ionizing radiation, such as that obtainable from fission by-products from nuclear fission plants. Radiation intensities of about 1,000 to 100,000 Roentgen/hour are suitable for this purpose.

Radioactive waste materials may also be used as a source of radiation to irradiate mineral oil products in the presence of basic salts in a desulfurization process. A hydrocarbon to be desulfurized is passed through a reaction zone containing an alkali, an alkaline earth hydroxide, oxide, carbonate, etc. while being irradiated from a radioactive source, such as radioactive waste material from atomic piles or radioactive metals, such as cobalt. Metals, such as zinc, mercury, tin, lead, etc, may also be used to react with the sulfur from the hydrocarbon. The hydrocarbon portion of the sulfur compound is not lost in this process as the result of cracking by the atomic radiation.

The invention may be advantageously applied to the improvement of high molecular weight hydrocarbon products, such as lubricating oils and fuel oils. For example, it has been found that the predominant reaction of carboxylic acids when exposed to radioactive radiation at low temperatures is decarboxylation. Acids formed in lubricating oils by oxidation during use may, therefore, be destroyed by subjecting the oils to radiation from radioactive fission products or the like at temperatures below about 400 F. In accordance with a specific modification of the invention, the source of radioactivity is sealed within the lubricating system of the engine to be lubricated, for example in the crankcase of a gasoline engine. In this manner, the carboxylic acids formed by oxidation are destroyed by decarboxylation as they are formed.

The same treatment of lubricating oils may be used to improve their viscosity and pour point characteristics which have been found to he beneficially affected by high intensity ionizing radiation of the type emitted by the by-products of atomic fission.

It is known that combinations of molybdenum sulfide with mineral lubricating oil have excellent lubrication and detergency characteristics. Highly efficient combinations of this type may be produced by exposing dispersions of small proportions, say about 0.1-2.0 wt. percent, of M08 in mineral lubricating oil to high intensity radiation from fission waste materials or other radioactive products at about 0300 F.

Similarly, highly desirable combinations of heavy fuel oils with lime may be produced. Heretofore, lime has been dispersed in fuel oil to reduce boiler slagging and corrosion by neutralization of acid fuel oil constituents. This effect is greatly improved when the lime-in-fuel oil dispersions are exposed to high intensity radioactive radiation of the type described above at about 0300 F.

Metals, as such, may likewise be added to hydrocarbons and other organic compounds with which they do not readily react. Exposure to high intensity radiation from fission products promotes the addition of such metals as lead, iron, nickel, cobalt, etc. to organic compounds with which they are in contact during the radiation process. For example, the irradiation of a mixture of gasoline and finely divided lead or lead compounds, such as lead naphthenate at 0-200 F., produces gasoline soluble compounds of value as anti-knock agents.

The above description and exemplary operations have served to illustrate specific embodiments of the invention. It will be understood that the invention embraces such other variations and modifications as come within the spirit and scope thereof.

What is claimed is:

1. An apparatus for irradiating chemical reactants which comprises a reaction container having a lower section and an upper section, a water impervious concrete member disposed between said lower and said upper section adapted to form a water impervious seal therebetween, radioactive material disposed Within said lower section comprising a gamma ray emitter of energy sufficient to pass through said concrete member, a shielding layer of water contained Within said upper section, a reactant chamber formed of material capable of passing gamma radiation disposed within said layer of water proximate to said radioactive material, and an earthen shield disposed adjacent said reaction container whereby radiation emitting from within said container is absorbed.

2. An apparatus for irradiating chemical reactants which comprises a reaction container having a lower section and an upper section, a water impervious concrete member disposed between said lower and said upper section adapted to form a water impervious seal therebetween, radioactive material disposed within said lower section comprising a gamma ray emitter of energy sufficient to pass through said concrete member, a shielding layer of water contained within said upper section, said water having a depth at least sufiicient to reduce the radiation intensity at a height of one foot above the surface of said water to 1 milliroentgen per hour, a reactant conduit having entrance and exit portions outside said reaction container and an intermediate portion disposed within said layer of water proximate to said radioactive material, said reactant conduit being formed of material capable of passing gamma radiation, and an earthen shield disposed adjacent said reaction container whereby radiation emanating from Within said container is absorbed.

3. An apparatus in accordance with claim 1 wherein said radioactive material comprises fission lay-products of processes generating atomic power.

4. An apparatus in accordance with claim 1 wherein said radioactive material is made radioactive by exposure to neutron irradiation.

5. An apparatus in accordance with claim 1 wherein said radioactive material has a radiation intensity in the range of 1x10 to 20X roentgens per hour.

References Cited in the file of this patent UNITED STATES PATENTS 1,627,938 Tingley May 10, 1927 2,015,282 Pacini Sept. 24, 1935 2,350,330 Remy June 6, 1944 2,743,223 McClinton a- Apr. 24, 1956 FOREIGN PATENTS 823.231 France Jan. 17, 1938 8 OTHER REFERENCES Breazeale: Nucleonics, November 1952, vol. No. '11, pp. 56-60.

U.S. Atomic Energy Commission BNL-141 by B. Manowitz et a1.

Dec. 1, 1951 Library date May 20, 1952 (ABC. documents are available from ABC, Technical Information Service, Oak Ridge, Tenn), pages 1, 2, 3, 4, 9, 12, 13.

US. Atomic Energy Commission BNL-171, issued September 1952. Library date Sept. 26, 1952, pages 37-43.

US. Atomic Energy Commission TID-3046, February 1954. Abstract 16 on page 8.

Manowitz: March 1953 Nucleonics, Comptes Rendue 228, 1490-4492 (1949).

US. Atomic Energy Commission M.DD.C. 785 Studies in the Preparation of Organic Radio-Halides, I. W. Richter. Declassified Mar. 18, 1947. Document consists of 37 pages, copy available from ABC. Oak Ridge, Tenn.

Engineering Research Institute, University of Michigan, Project M 943, US. Atomic Energy Commission, Chicago 80, Illinois, Progress Report 1, August 31, 1951, pp. 28, 29, -44, 52 and 53; Progress Report 4, March 1953, 5 1. 94 9s, 102, 103, 105, 107.

pages 18-20.

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