US2419212A - Reformed hydrocarbon wood preserving impregnant - Google Patents

Description

Patented Apr..22, 1947 REFORMED HYDROCARBON WOOD PRESERVING IMPREGNANT J acquelin E. Harvey,

Robert H. White, Jr.,

Jr., Washington, D. 0., and and Joseph A. Vaughan,

Atlanta, Ga., assignors of one-half to said 1 Harvey and one-half to Southern Wood Preserving-Company, East Point, Ga., a corporation of Georgia No Drawing. Application October 7, 1944, Serial Ni 557,727

2 Claims;

This invention relates to the production of toxic oils employable as fungicides, insecticides and for any other service to which toxic oils may beput, as for example, burning oils, for it is well known that toxic oils may be used as fuels.

More especially the instant invention relates to the production of toxic impregnating oils, as for example wood preservative impregnants, from mixtures of petroleum fractions characterized by ring structure content. Among such starting materials may be mentioned mixtures of petroleum fractions. characterized by ring structure content recovered from petroleum fractions by well known extraction methods including extractive distillation, solvent extraction and 'azeotropic distillation. Also may be mentioned mixtures of petroleum fractions characterized by ring structure content as flowing from thermal and/or catalytic treatment of certain petroleum fractions which includes petroleum fractions having ring structures induced in the course of thermal and/or catalytic treatment, as for example, having ring structures induced in the course of one or more thermal and/or catalytic treatments of unusua1 length, say for periods of 1-10 hours or more.

Specifically the instant invention turns on reforming, cracking, transforming; modifying and/or converting a mixture of petroleum fractions characterized by a substantial percentage of materials of ring structure content so as to pro-'- vide a finally'beneficiated material from which may -be segregated an oil of the wood preservative type boiling preponderantly between 210 C. and 355 0., having at least about 70% materials of ring structure content, and in its 315-355 0. fraction certain characteristics which lessen the toxicity blanketing effect of said fraction on materials boiling below that temperature.

\ In oily wood preserving impregnants it is found that the materials boiling below 315 C. have a relatively, high toxicity whereas the fraction 315- 355 C. has a relatively low toxicity. For matters of concrete consideration let it be assumed that 2 the materials boiling below 315 C. have a tox-'- icity to wood destroying fungi of 0.25, and the fraction 315-355" C. has a toxicity of 1.00. If the materials boiling below 315 C. represent 75% of the total preservative and the fraction 315- 355 C. represents 25%, then logic would suggest that the overall toxicity of the preservative would be as per the following equation:

Overall toxicity=(0.75 x 0.25) +(0.25 x 1.00). However, logic does not support actual facts in this case, for it is found that the 315-355 C. fraction has a toxicity blanketing effecton ma- .terials boiling below that temperature to such an extent that the overall toxicity'is less than indicated'by the above equation.

Tha toxicity data (total inhibition point) above noted is expressed as the percentage of the preservative by weight of medium on which tested and required to totally inhibit the growth of the fungus under test. This toxicity test is fully described on page 34 et seq. of the 1933 Proceedings of the American Wood Preserve'rs Association.

We ,have discovered that if we will provide in the cut boiling between 210 C. and 355 C. of our beneficiated petroleum at least about 70% of materials of ring structure content, the while providing certain specific gravity limits in the 315-355 C. fraction of the beneficiated oil and/or certain specific gravities of aromatics in said last named fraction, we can limit to an extraordinary degree the toxicity blanketing effect of the 315-355 C. fraction on the materials of relatively high toxicity boiling below that temperature.

This matter is fully set forth and describedin the following.

It is a matter of record that exceedingly large quantities of petroleum aromatics are available in the petroleum industry, but diligent research has shown that these aromatics are not as toxic to wood destroying fungi as the aromatics of coal tar derivation. Be the reason what it may for petroleum aromatics not having a toxicity equalling or closely approaching the toxicity of coal tar aromatics, we have discovered that if we take as starting material a mixture of petroleum fractions characterized by a preponderance of petroleum aromatics and subject same to thermal and/or catalytic treatment with or without a gas of extraneous source, provided we jointly secure in the reformed oil boiling between 210- 355 C. not less than about 70% of materials of ring structure content, and in the fraction boiling between 315-355 C. a specific gravity falling between the limits of about 1.1175 and 1.3888 and/or a specific gravity of aromatics in said last named fraction falling between the limits of about 1.12851.5539, we will have reduced to an unobjectionable point the toxicity blanketing effect of said 315-355 C. fraction upon the materials'boiling below that temperature in the beneflciation.

As representative of the boiling ranges of wood preservatives that can be segregated from the beneficiation of the instant process, we list below wood preservative specifications previously published.

Woon Pnassavsrrvn Imraacmn'rs Specifications 1. American Wood Preservers Association aup to 210 C., not more than bup to 235 C., not more than 25% 2. American Wood Preservers Association a-up to 210 C., not more than 1% bup to 235 C., not more than c--up to 355 C., not less than 65% 3. American Wood Preservers Association (bup to 235 C., not more than 1 /2% bup to 300 C., not more than l6/2% c-up to 355 C., not less than 45% 4. American Wood Preservers Association a up to 210 C., not more than 8% bup to 235 C., not more than 35% 5. American Wood Preservers Association o-up to 210 C., not more than 10% bup to 235 C., not more than 40% 6. American Wood Preservers Association a-up to 210 C., not more than 5% bup to 235 (3.. not more than 7. Prussian Ry.

cup to 150 C., not more than 3% bup to 200 C., not more than 10% cup to 235 C., not more than 25% 8. National Paint Varnish 8i Lacquer Association #220 a5% at 162 C. b97% at 270" C. 9. Southern Pine Shingle Stain Oil a5% at 137 C. b95% at 257 C. Neville Shingle Stain Oil a-I. B. P., 150 C. b- 5% at 205 C. c-95% at 292 C. 11. Carbolineum, 270 C., I. B. P.

As representative 0 petroleum aromatics" that are included in our starting materials, we

cite the following oil of cyclic structure content produced (1940) at the Wood River Refinery of the Shell Oil Company, and which had the following inspection:

Gravity 10.8 Flash, P. M. C. C., "F 295 Flash, C. O. C., "F 290 Fixed carbon, percent 4.9 Pour point, F 10 B. S. 8: W. percent by volume 0.1 S. U. vis. 100 F 151 4 s. U. vis. 210 F 41 S. F. vis. 77 F 34.5 Carbon residue 6.8 Percent aromatics and unsaturates 82.4 Sol. in CS2 99.8 Loss 50 grams, 5 hours, 325 F 8.9 Residue of 100 pene., percent 37.5 A. S. T. M. distillation:

I. B. P., F 518 10% Rec. "F 565 20% Rec. F 589 30% Rec. F 614 40% Rec. F 637 50% Rec. F 660 Rec. F 675 max.

In the foregoing tabular data P. M. C. C. means Pensky-Martin Closed Cup; C. O. C. means Cleveland Open Cup.

Upon evaluating the foregoing oil for its toxicity to Wood destroying fungi (Madison 517) it was found that this oil did not totally inhibit the growth of the fungi named at a concentration of up to and including 10%. Madison'517 is a strain of the fungus Fones Annosus.

We have discovered that the oil above named or other oils of cyclic structure content produced by the petroleum industry can be increased in toxicity in accordance with the process of the instant invention.

The following examples will serve to illustrate several modes of practicing the process of instant invention.

Escample 1.--A mixture of petroleum fractions, as for example, the Shell oil shown in the foregoing tabular data, is divided into a material boiling below 315 C. and amaterial boiling above that temperature. The material boiling above 315 C. is charged to an autoclave capable of withstanding high temperature and high pressure and under autogenous pressure brought up to-a. temperature of 550 C., at which temperature it is held for a period of one hour. The beneficiated material is inspected and the 315355 C. out is found to have a specific gravity falling between the limits of 1.1175 and 1.3888. The segregated raw feed materials boiling below 315 C. are subjected to a heat treatment under autogenous pressure at a temperature of 495 C. for a period of one hour.

All materials from the treatments above named are cooled to atmospheric pressure and the liquids blended. The commingled heat treated liquid materials provide an oil'having a toxicity to wood destroying fungi in excess of the parent feed stock. The comminglement is fractionally distilled to yield as a distillate a wood preservative impregnant of induced toxic properties having more than 70% of materials of ring structure content,

5% distilling below 210 C. and 25% matter above 355 C.

Example 2.-A petroleum aromatic having an A. P. I. gravity of about 10.5, a percentage of arcmatics and unsaturates of about 82%, an initial boiling point of about 260 C. and a 70% point at about 350 C. is fractionally cut at 300 C. The materials boiling above 300 C. are char ed to a high pressure autoclave and brought up to a temperature of 525 C., and there maintained at the named temperature under autogenou-s pressure for a period of one hour and 15 minutes. The beneficiation is cooled to atmospheric temperature and inspected, and found to have in its 315-355 C. out, a specific gravity of aromatics falling between the limits of 1.1285 and 1.5539.

residual The segregated raw materials boiling below 300 C. resulting from the fractionation above named are subjected to a cracking treatment at 505 under autogenous pressure for a period 50 minutes.

The separately heat treated materials which remain liquid after coolin are commingled and are found to have a toxicity to wood destroying fungi in excess of the parent feed stock. The segregation is extracted with liquid sulfur dioxide, and the raffinate discarded. After removal of the liquid sulfur dioxide from the extract, the latter is stabilized to provide a residual as a wood preserving impregnant having superior toxicity to wood destroying. fungi because of the fact that, among other things, the specific gravity of arcmatics in the 315335 C. fraction fell between 1.1285 and 1.5539. The stabilized residual has in excess of 85% of materials of ring structure content and boils preponderantly between 210 C and 355 C.

The foregoing examples have been cited to show illustrative treatments of'the feed stocks which have been divided into a high boiling portion and a low boiling portion, In lieu of this procedure, the starting material may be cut into several fractions, as for example, three or more fractions. The thus segregated fractions of the raw material may be separately heat treated in accordance with the instant process, as for ex ample, the lowest boiling out treated at a relatively high temperature within the limits hereinafter stated, and the highest boiling cut at the lowest temperature, the intermediate segregation being treated at an intermediate temperature within the namedv limits. Comminglement of the heat treated fractions and subsequent segregation of the wood preservative impregnant is in accordance with teachings herein set forth.

Example 3.-Tlie Shell oil shown in the foregoing tabular data; or:. a.counterpart thereof, is

charged to a. high; pressure autoclave and water as pumped intof an upper limit of 300 pounds per square inch..;The contents of the autoclave are brought upto a temperature of 550? C. and

there held for a-period of-two hours and 30 minutes. At the-"end of thenamed period the beneficiationis cooled and inspected and-is found to have, in the materials boiling between 210-355 C.

a. percentage' 'ofaromaticsin excessrof 80%, and

in the-3l5'-355 'C. cut'an overall specific gravity "falling'between the limits of 1.1175 and 1.3888. The beneficiated material remaining liquid under the reaction conditions is fractionally-distilled to provide a distillate boiling 2% below 210 C. and

with boiling above 355 C. Research discloses the fact that the overall toxicity of the distillate is of a superior order because, among other things, the specific gravity-of the 315-355 C. out had been controlled between the limits of 1.1175 and 1.3888.

Example 4.A petroleum aromatic oil as for example, the Shell oil previously described, is

pumped in closed circuit through an apparatus designed to withstand high pressure and high 7 temperature. -The pressure is maintained at 1000 pounds Der square inch. The temperature is J25 C. The oil in closed circuit is kept in circulation. At the/end of about two hours the heat treated oil is'withdrawn with compensating admission of fresh feed to the circuit. The with- ,dr awal and admission are so regulated as to provide the two hour heat treating period above named. Upon inspection of the withdrawn heat the beneficiation will compare favorably with high temperature coal tar creosote, and the specific gravity of the 315355 C. out will be found to fall between limits previously named,

Example 5.We have discovered, as previously disclosed, that we can induce superior toxicity into mixtures of petroleum fractions provided we secure a beneficiation having 'at least about 70% aromatics in the oil boiling between 210 C. and 355 C. and in the SIS-355 C. cut a specific gravity falling between the limits above. named and/or a specific gravity of aromatics in said out falling between limits previously described. However, we have found that when processing the starting materials in accordance with the instant process certain reactions go forward which tend to reduce the relatively high toxicity of the newly formed oil when viewed from the standpoint of peak toxicity induction. We have determined that we can eliminate or control to a degree the above-named reduction in toxicity, if after the 250 C., and preferably below 200 C. A relatively cool oil previously made by the process may be the quenching oil which shock cools the beneficiation, Thus, this specific mode of operation as exemplifying our invention turns on heat treating the starting material for such a period as to jointly provide not less than 70% aromatics in the 210-355 C. fraction and the named specific gravity limits in the 3l5-355 C. cut, and thereafter shock cooling the beneficiation whereby to provide superior toxicity.

Example 6'.--The shell petroleum aromatic oil noted previously, or a counterpart thereof, is subjected to a temperature of 485 C. for a period of minutes. Thereafter the partially beneficiated material is subjected in entirety to a temperature of 600 C. for a period of 20 minutes, the pressure in both instances being autogenous. The beneflciated material is cooled and inspected and is found to have newly formed fractions boiling below 210 C. and'in the materials boiling between 2l0-355 C. in excess of 95% aromatics. The specific gravity of aromatics in the 315-355 C. out of the beneficiation falls between the limits noted previously. A toxicity evaluation of the materials boiling between 210-355 C. indicate that not more than about 0.5% is required for total growth inhibition of wood destroying fungi. A distillate boiling preponderantly between 210-355 C. is cut from the beneficiation to provide said distillate as a material having a toxicity to wood destroying fungi comparing favorably with that of high temperature coal tar creosote.

Example 7.-A petroleum aromatic oil distilling 30% below 270 C. and with residue above 355 C., having an aromatic and unsaturated content of over and a specific gravity of aromatics of 1.0256 in the 315-355 C. fraction is subjected to a temperature of 525 C. while under a pressure of 1000 pounds per square inch for a period of one hour. Thereafter the heat treated material in entirety, without substantially lowering the temperature by outside heat exchange, is held under a pressure of 400 pounds per square inch for a period of 30 minutes. At the end of the named second period the beneficiation is cooled and inspected and is found to have in excess of 70% aromatics in the materials boil- 7 lag between 210-355 0., and in the fraction 315-355 C. a specific gravity of aromatics falling within the limits previously noted.

The beneficiation which has newly induced fractions boiling below 210 C. is fractionally distilled to provide a distillate of the wood preservative type boiling preponderantly between 210 C. and 355 C. A toxicity evaluation of the wood preservative type distillate shows that its toxicity closely approaches that of high temperature coal tar creosote.

In the two-step operation disclosed in the instant example we have found that a period of not in excess of about one hour is suitable for the primary step. Dependent upon the temperature selected within the range herein disclosed, periods of 20, 30 or 40 minutes, more or less, are acceptable. In the secondary step in this mode of practicing the instant process, we have found that a period not in excess of about one hour is sufilcient to induce the final desired qualities. employing in the first stage a relatively high temperature within the range herein disclosed, and

a relatively high pressure drop in the second stage, a relatively short period of treatment in the second stage of relatively low pressure will provide the desired percentage and specific gravity of aromatics.

The relationship of the relatively high and lowpressure steps may vary over broad limits, a for example, the first step may be carried out at a very high" pressure and the second step at a pressure only slightly above atmospheric. On the other hand, if a relatively low pressure is employed in the first and relatively high pressure step, say a pressure of about 300 pounds per square inch, then atmospheric or subatmospheric pressure may be employed in the second step.

Viewed broadly, this phase of practice, of our invention is not circumscribed by any definite pressures in the relatively high and low pressure steps, but rather turns on employing a relatively high pressure in the first stage and a relatively low pressure in the second stage, be the separate pressures what they may.

The practice of the proces of the invention as instantly described is carried on. at temperatures selected between the limits of about 400-750" C., and preferably between the limits of about 450-600 C. The pressures are, with the exception of an example previously noted, in excess of atmospheric, and may be as high as practicable.

We have found that in order to provide the stated specific gravities in the 315-355 C. fraction a period of not in excess of about three hours l is satisfactory for the induction of the desired characteristics in the feed stock, be the treatment a single or dual phase operation.

At times when only feed stocks are available having a relatively low content of materials of cyclic structure content, it is advisable to first extract the starting stock by liquid sulfur dioxide or the like, discarding the raffinate and employing the extract as charging stock. Likewise the extraction of the beneficiation may be practiced, and this statement is to be read into any and all examples as providing one mode of practicing our process.

In the examples previously shown, intermittent operation has been cited. It is obvious, of.

course, that continuous operation may be substituted by those skilled in the art without re-' crease of toxicity induction flows from our em- When i ployment of a gas of extraneous source with the charging stock at the time of cracking,.reforming, transforming, modifying and/or converting. We specifically state that the employment of an extraneous gas or gases, active or non-reactive under the process conditions, is to be read into any and all of our examples. The employment of the said gas or gases will entail no inventive skill when applied by those skilled in the art. Among the gases employable in the instant process are hydrogen, carbon-monoxide, carbon dioxide, nitrogen, methane and its homologues, including specifically waste refinery gases or the like, separately or in admixture.

We have found in our provision of a sup i wood preserving impregnant from mixtures of petroleum fractions which have relatively low toxicity to wood destroying fungi, that if we carry on our cracking, reforming, transforming, modifying and/or converting operation in the presence of catalytic materials adapted to promote said action, we secure certain toxicity benefits. Among the catalytic materials that we have found to be employable with advantage, we can specifically name the oxides and sulfides ofv metals (preferably the oxides and sulfides of the 6th and 8th periodic groups), halogens, halides and derivatives thereof, including substitution and addition products thereof, active carbon, and especially active carbon produced under high temperature pyrolysis, siliceous materials, or the like, separately or in combination.

We have specifically found'that active carbon induced during the course of py olysis of hydrocarbons or carbonaceous materials has a very marked effect on the induction of toxicity, and

, we specifically claim this catalyst as especially beneficial in our process.

The halogens, etc. above named may be employed in a percentage, based on the feed stock, of between 0.1% and about 3%. Other and solid catalytic materials may be supplied in finely divided form in a percentage of from 0.5 to 10% of feed stock or the reaction chamber may be' partially filled with the-catalytic materials.

The foregoing examples illustrate our process named, is specifically to be read into all examples.

In the foregoing, examples have been shown without catalysts, while other examples have been shown without the employment of a gas of extraneous source. Insofar as the employment of a catalyst and/or gas or gases is obviously workable, the inclusion of catalytic materials and/or extraneous gas or gases are to be specifically read into all examples. Certain toxicity benefits flow from such employments.

By the expression a reformed petroleum oil is meant a petroleum oil processed in accordance with disclosures made herein.

Minor changes within the scope of the appended claims may be made without departing from the spirit of th invention.

We claim:

1. As a wood preserving impregnant a reformed petroleum oil boiling preponderantly between 210355 0., characterized by at least 70% of materials of ring structure content and at least about 15-20% of residue above 315 C., the fraction SIS-355 C. of which has a specifie gravity fallingbetween the limits of about 11175-13838.

2. As a wood preserving impregnant a reformed petroleum oil boiling preponderantly between 210-355" 0., characterized by at least about 70% of materials of ring structure content and at least about 15-20% of residue above 315 C., the fraction 315-355 C. of which contains.

aromatics having specific gravities falling -between the limits of about 1.12 85-15539.

JACQUELIN E. HARVEY, JR. ROBERT H. WHITE, JR. JOSEPH A. VAUGHAN.

10 REFERENCES CITED Thefollowing references are of record in the file of this patent:

I UNITED STATES PATENTS Number Name I Date Young et a]. l Apr. 17, 1934 Warner et a1. June 6, 1939 English et a1 Sept. 26, 1939 Carpenter Oct. 24, 1939 Sachanen et aL, I Nov. 26, 1940 Sachanen et a1., II Feb. 15, 1944 Shipp et a1 Apr. 24, 1945