IN D US TR I A L A N D EN G I N E E R I N G C H E M I STR 1
September, 1933
LITERATURE CITED (1) Allen, Chem. & Met. Eng., 32, 928 (1925). (2) Badger, IND.EBG. CHEM.,19, 677 (1927). (3) Benson, “Chemical Utilization of Wood,” Rept. Xatl. Comm. Food Utilization, Dept. Commerce, 1932. (4) Benson, Pacific Pulp Paper Znd., 6 , 30.13, 19 (1932): Paper Trade J , 95, KO.20, 31 (1932).
983
Kobe, Paper Trade J.,95, S o . 3, 33 (1932). Kobe, Conrad, and Jackson, IND. ENG.CHEM.,25, 984 (1933). Kobe and Hauge, Power, 77, 402 (1933). Kuhles, Ibid., 72, 468 (1930). (9) Miller, Can. Chem M e t . , 14, 19 (1930). (5) (6) (7) (8)
RECEIVED February 21, 1933.
Efficiencies of Tar Oil Components as Preservative for Timber F. H. RHODESAND IRAERICKSON,Cornell University, Ithaca, 3. Y.
I
S THE determination of the fungicidal powers of creosote
oil fractions by the wood pulp method of Rhodes and Gardner, the use of pine pulp gives results consistent with those obtained when Norway spruce pulp is used. No one compound in coal-tar creosote oil is primarily responsible for its preservative power, although diphenyl appears to be slightly more toxic to fungi than any other single compound. The fractions from water-gas tar oil are much les- effective as preservatives than are those from coal-tar creosote oil. The chlorine derivatives of phenol and creosols and of naphthalene are more toxic to fungi than are the compounds from which they are obtained. This investigation is essentially a continuation of that of Rhodes and Gardner ( 2 ) . I n this earlier work a method was devised for measuring the fungicidal powers of wood preservatives by determining the minimum concentration of preservative required to prevent the growth of Fornes annosus in mechanical wood pulp. The conditions in this test resemble, in many respects, those under which the preservatives are actually used, so that the experimental results should be indicative of the results that may be expected in service. This method of testing was used in the present investigation also. A possible criticism of the original method of Rhodes and Gardner is that the test material was mechanical wood pulp from Norway spruce, which is not commonly used for structural purposes. To determine whether or not the apparent efficiency of the preservative varies with the specific type of wood pulp used, parallel tests were made with careosote oil fractions as the preservatives, using Xorway spruce and mechanical pine pulps. The mechanical pine pulp was obtained through the courtesy of the Forest Products I abmatory, Madison, Wis. The results were as follows: -LIMITING
OIL FRACTION
CONCENTRATIONSO--
S O R W A Y SPRUCE PULP
A
B
A
B
%
%
%
%
0 s 1 0 0 6 0 8 0.6 0 8 0 6 0 8 9 0 6 0.8 0 6 O S a A , maximum concentration a t which any g r o a t h of F annosus occurs, B, minimum concentration at which no growth of F annosus ,occurs
5 7
It appears that within the limit of experimental error the results of the test do not depend upon the specific type of pulp used. Several investigators in this field have made comparisons of the relative efficiencies of preservatives by determining the concentrations of the various preservative substances that are required to inhibit the growth of the wood-destroying fungi in a malt-agar medium, or the concentration required to kill the fungi in such medium. One such method has been described by Schmitz and others ( 3 ) . This method is a
convenient one, although the conditions of the test differ so markedly from those of actual service that, in some cases at least, the results inay not be directly comparable with those that may be expected in practice. A series of fractions from coal-tar creosote oil was tested by the methods of Schmitz and of Rhodes and Gardner. The results were as follows: KILLINGCOSCESTRI T I O A N e t h o d of Rhodes hlethod of Schmitz
F R ~ C T I O N and Gardner yo by u e t g h t
o/ Load p u l p
1 2
0.9
0.03 0.03 0.03 0.03 0.03 0.03 0.05 0.05 0.08 0.15 0.05
0.7
3 4 5
0.55 0.7 0.1)
0.7 0.9 1.3
6
; 9
:.s
10 ,\I ixt ure
R~TIO
% by uezght o/ agar medium
0.9
30:l 23:l 18:l 23:l 30:l 23:l 18:l 26:l 21:l 18: 1 18: 1
These results show that in the comparison of the preservative efficiencies of variouh fractions from coal-tar creosote oil the two methods give reasonably consistent results, although quantitatively the concentration required to kill Fomes annosus in an agar medium is much lower than that to prevent the growth of this organism in wood. COAL-TARCOhTPOUNDS The matetial used in this series of tests was prepared from a typical coal-tar creosote oil that showed the following analysis: PERCENTDISTIL LED^
TEMP.R A N G E
(BY
c.
WEIGAT)
0-2’10 1.2 14.3 235-270 20.8 270-3 15 20.5 20.2 3 15-355 Residue 21.0 Limpid point, C 27 Sp. gr. (38/15.5j C.’ 1.065 T a r acids, % 11.6 T a r bases. 5% 5.9 Bulb distillation by:l S T hl method D246-27T 2 10-235
Several gallons of this material were freed from tar acids and bases by repeated alternate extraction with a 10 per cent solution of sodium hydroxide and a 30 per cent solution of sulfuric acid. Two liters of the resulting “dead oil” were distilled from an iron still provided with a Hempel fractionating column, and the distillate was collected in ten approximately equal fractions, as follows: FRhCTIOs
DISTN TEMP
Fn4crros
“C
1
2
3 4
184-210 210-225 225-240 240-260
5 6
7
DIJTN. TEMP.
c.
260-290
290-300 300-310
DISTN.
FRICTION TEMP.
oc
S 9
10
310-320 320-340 340-385
INDUSTRIAL AND ENGINEERING CHEMISTRY
990
Vol. 25, No. 9
The preservative efficiency of each fraction and of a mixture of equal parts by volume of the separate fract,ions was then determined by the wood pulp method. The following results were obtahed:
average preservative effect, and even this compound shows only slightly more than average efficiency.
LIMITING LIMITINQ LIXITING FRACTIONCONCN. FRACTION CONCN. FRACTION CONCN. % % V." " .-
In view of the fact that the oils distilled from water-gas tar are used to some extent as preservative for timber, it was thought advisable to make some comparison of the preservative efficiencies of coal-tar oils and water-gas tar oils. The raw material used in the preparation of the water-gas tar oil was crude water-gas tar obtained from the Ithaca plant of the New York State Gas and Electric Corporation. The crude tar was distilled to hard pitch in an iron still, and the total distillate was collected. This distillate was then redistilled through a Hempel column, and the second distillate was collected in t,en fractions of approximately equal volumes. The preservative efficiency of each fraction and of a mixture of equal parts by volume of the various fractions was then determined, using the wood pulp method. The results were as follows:
0.8-1 .o 0.6-0.8 0.5-0.6 0.6-0.8
1 2 3 4
I-
5 6 7 8
0.8-1.0 0.6-0.8 0.8-1.0 1.2-1.4
9
10
Mixture
1.4-1.6 2.5-3.0 0.8-1.0
The lower fractions from the coal-tar dead oil show very little variation in preservative power; the high-boiling fractions are less effective than are those of lower boiling points. A certain amount of high-boiling material is, however, probably desirable in commercial creosote oil because of its effect in reducing the volatility of the oil and thus aiding in holding the oil more permanently in the wood. A portion of coal-tar dead oil, prepared as described above, was distilled through a Hempel column, and the total distillate passing over between 190" and 310" c!. was collected. To portions of this distillate, known amounts of m-cresol, 0-cresol, diphenyl, naphthalene, oc-methylnaphthalene, and &methylnaphthalene were added, and the preservative efficiency of each mixture was determined. The methylnaphthalenes were purified by washing with concentrated sulfuric acid, concentrated solution of sodium hydroxide, and water, and were then steam-distilled and, finally, redistilled under reduced pressure. The other compounds were purchased as c. P. material and were not further purified. The preservative efficiencies are given in Table I. TABLE I. PRESERVATIVE EFFICIENCIESOF COAL-TAR
COMPOUNDS
PBESERVATIVE
/ "
++ +
++ l o503 o-cresol % zz:; Dead oil + 1% diphenyl ++ 25 %% diphenyl diphenyl +lo% diphenyl Dead oil + 1% naphthalene ++ 25%% naphthalene naphthalene + l o % naphthalene Dead oil + 1% a-methylnaphthalene ++ 25% 9 , a-methylnaphthalene a-methylnaphthalene + l o % a-methylnaphthalene
Dead oil
Pure Pure Pure Pure Pure Pure
+ 1 % @-methylnaphthalene + 2 % @-methylnaphthalene + 5% @-methylnaphthalene + l o % @-methylnaphthalene
m-cresol o-cresol diphenyl naphthalene a-methylnaphthalene @-methylnaphthalene
FR.ACTION
DIBTN. TEMP.
c. 1 2 3 4 5 6
135-206 206-217 217-223 223-229 229-232 232-240
LIMITISG CONCN.
FRACTION
DISTN. TEMP.
c.
% 1.5-1.6 1.6-1.7 1.7-1.8 1.7-1.8 1.6-1.7 1.4-1.6
7 8 9 10 Mixture
240-247 247-260 260-275 275-317
..,.,.,
LIMITINQ CONCX.
% 1.1-1.2 1.0-1.2 1.2-1.3 1.4-1.6 1.7-1.8
It appears that the oils from water-gas tar are only about one-half as effective as are those from coal tar. The fraction that distills between 247" and 260' C., which should contain most of the diphenyl as well as considerable amounts of naphthalene and methylnaphthalene, has definitely higher preservative power than any other fraction.
LIMITINGCONCN. %"
Dead oil (190-310O C.) Dead oil 1% m-cresol 2 % m-cresol 5% m-cresol +lo% m-cresol Dead oil +' $l o-cresol
FRACTIONS FROM WATER-GAS TAR
0 . 8 - 1 .o 0 . 8 - 1 .0 0 . 8 - 1 .o 0.6-0.8 0.6-0.8 0.8-1 . o 0.8-1 . O 0.6-0.8 0.6-0.8 0.8-1.0 0.6-0.8 0.6-0.8 0.4-0.6 0 . 8 - 1 .O 0.8-1.0 0.6-0.8 0.6-0.8 0.8-1.0 0.8-1.0 0.6-0.8 0.6-0.8 0.8-1 . o 0 . 8 - 1 .O 0.6-0.8 0.6-0.8 0.7-0.8 0.7-0.8 0.4-0.6 0.6-0.8 0.6-0.8 0.6-0.8
The results indicate that no one of the normal and principal components of ordinary coal-tar creosote oil is primarily responsible for the preservative action of the oil. In general, naphthalene and the methyl naphthalenes have about the same preservative efficiency as have the lower fractions of the normal dead oil, and the addition of these compounds does not increase the efficiency of the oil. Phenol and cresol aie no more efficient as fungicides than are the neutral aromatic hydrocarbons, and any advantage to be derived from the presence of the tar acid in the oil must be due to causes other than the increase of the fungicidal power. Of all of the compounds studied, diphenyl alone shows more than the
CHLORINEDERIVATIVES OF AROMATIC HYDROCARBON AND
PHENOLS
It is well known that the bactericidal powers cf the chlorine derivatives of the aromatic hydrocarbons and phenols are usually higher than those of the hydrocarbons or the phenols themselves. In view of this fact, it is possible that the chlorine derivatives of the components of creosote oil may be better preservatives for timber than are the compounds from which they are derived. Curtin and Bogert ( I ) measured the fungicidal powers of chlorinated naphthalene and of the crude products obtained by the direct chlorination of coal-tar creosote oil and of various crude fractions of the tar acids from creosote oil. The determinations of fungicidal power were made in standard agar-malt sirup gels, so that their results may not be directly comparable with those obtained by the wood pulp method. They concluded that: (1) The chlorination of aromatic hydrocarbons of molecular weight equal to or greater than that of naphthalene results in a decrease in toxicity; (2) the chlorination of the crude cresols or the crude xylenols from coal-tar creosote oil is accompanied by an increase in fungicidal power; and ( 3 ) chlorination of the crude mixtures of high-boiling tar acids from creosote oil, distilling between 270" and 300" C., results in a decrease in the preservative efficiency. The decrease in toxicity that was observed when high-boiling fractions were chlorinated was explained on the basis of the hypothesis that the chlorine derivatives are less soluble in water than are the hydrocarbons from which they are derived. We have measured the preservative efficiencies of a few pure chlorine derivatives of the aromatic hydrocarbons and phenols, and the results of these tests, together with the results of tests made with the hydrocarbons and phenols themselves, were as follows:
September, 1933 COMPOUND
INDUSTRIAL AND ENGINEERING CHEMISTRY LIMITINQ CONCN.
COMPOUND
%
% p-Dichlorobenzene a-Chloronaphthalene 8-Chloronaphthalene p-Chlorophenol o-Chlorophenol
1.3-1.4 0.4-0.5 0.5-0.6 0.34.4 0.6-0.7
LIMITINQ CONCN.
2-Chloro-5-hydroxytoluene Phenol o-Cresol Naphthalene
0.5-0.6 0.8-1.0 0.7-0.8 0.6-0.8
The present results agree with those of Curtin and Bogert in indicating an increase in fungicidal power upon the chlorination of the lower phenols, although the relative increase was very much less than was found by them. Contrary to their results, the writers find that the chloronaphthalenes appear to be better preservatives than is naphthalene itself, although the differences are not large. The discrepancies between our results and those of Curtin and Bogert are due, apparently, to the difference in the method used for the
991
determination of preservative efficiencies. The former investigators used the agar plate method, in which the results depend to a marked extent upon the solubi!ity of the preservative in water: in the mood pulp method (and probably also in service) slight variations in solubility have relatively less effect. LITERATURE CITED (1) Curtin and Bogert, ISD.ENG.CHEX, 19, 1231 (1927). (2) Rhodes and Gardner, Ibid., 22, 167 (1930). (3) Schmitz and others, Ibid., Anal Ed., 2, 361 (1930); see also Schmitz and Zeller, IND.ENG.CHEM.,13, 621 (1921); Schmitz and Buckman, I b i d . , 24, 772 (1932). RECEIVED March 6, 1933. The work described here was done under a fellowship maintained a t Cornel1 University by the American Creosoting Company.
Dry Distillation of Residue of Waste Sulfite Liquor MAXPHILLIPS, Bureau of Chemistry and Soils, Washington, D. C.
I
X A PAPER recently published from this laboratory ( 7 ) results of an investigation were presented dealing ITith the dry distillation of alkali lignin in a reduced atmosphere of carbon dioxide. I n this paper the results are given of a similar study on the dry distillation of the residue of waste sulfite liquor. Ahrens (1) was the first to make a study of the products of the dry distillation of waste sulfite liquor. He neutralized the liquor with lime, then evaporated the solution to dryness, and subjected the residue to dry distillation. The distillate was found to contain acetone and acetic acid, together with an oil containing sulfur, The carbonized residue contained 33.6 per cent ash and 4.37 per cent total sulfur. Bantlin (2) partly separated the volatile sulfur compounds from waste sulfite lye by passing through it a current of air and steam. The solution was then evaporated t o dryness and the residue distilled. A small yield of liquid products was obtained and no methanol, while large quantities of hydrogen sulfide and mercaptans were evolved. I n view of the rather meager information found in the literature with respect to the composition of the distillate obtained when the dry residue of waste sulfite liquor is subjected to dry distillation, the investigation described in this paper was undertaken. EXPERIMENT.4L PROCEDURE
PREPARATION OF MATERIAL. Waste sulfite liquor concentrated to the consistency of sirup was kindly furnished by The Brown Company, of Berlin, N. H. The total solids in this product amounted to 51.37 per cent. The product was evaporated to dryness, dried a t 105" C., and ground to a powder. This dry material analyzed as folloas: Ash, 19.03 per cent; sulfur, 6.84 per cent; methoxyl, 6.54 per cent. APPARATUS.The apparatus described in a previous communication (7) was used for these experiments. The distillation experiments were carried out in a manner similar to that described in the article on the dry distillation of lignin from corncobs ( 7 ) . For each experiment, 300 grams of the dry residue from waste sulfite liquor were used. The air in the apparatus was first replaced with dry carbon dioxide and then evacuated to 25 mm. pressure. A small stream of dry
carbon dioxide a t the rate of about one bubble per second was passed through the apparatus during the distillation experiment. The temperature was gradually increased until the maximum of 400" C. was obtained. The gases given off had a very obnoxicus odor. The presence of hydrogen sulfide and mercaptans could be detected. The distillate consisted of a milky, aqueous liquid and an oil. Because of the relatirely small amount of oil in the distillate, no attempt was made to separate it from the aqueous portion of each individual experiment. In each experiment the weight of the distillate and of the carbonized residue in the retort was determined. No attempt was made to collect the gaseous products, and the weight of the latter was obtained by difTerence. The results of ten experiments are given in Table I. TABLEI. PRODUCTS OF DRY DISTILLATION OF SULFITELYE [300 gramm material used in each experiment (222.6 grams calculated on ash- and sulfur-free basis) I TOTALDISTILLATE (OIL AQWEOUBDISTILLATE) CARBONIZBD Yield (calcd. RESIDUE^ GASEOUS P'RODUCTBb OD ash- and SE X P T . Weight Yield free material) Weight Yield Weight Yield Grams Grama % Grama % % % 1 166 55.3 62.0 20.7
+
2 3 4 5 6 7 8 9 10
167 168 167 160 165 164 164 161 170 165
55.6 56.0 55.6 53.3 55.0 54.6 54.6 53.6 56.6 65.0
64.0 63.0 63.0 65.5 64.0 62.5 64.0 66.0 60.0 63.6
21.4 21.0 21.0 21.9 21.4 20.9 21.4 22.1 20.1 21.2
Mean A composite sample of the carbonized residue was sshed and found to yield 35.90 per cent ash. b By difference. (1
EXAMINATION OF AQUEOUS DISTILLATE The aqueous distillates from the ten experiments were combined. To this Norit was added, the mixture was well shaken and allowed to stand a t room temperature for 2 hours. This was filtered, and the filtrate made up to 1000 cc. in a volumetric flask; 250 cc. of this solution were treated with 4 per cent potassium permanganate until no further reduction took place. This was for the purpose of oxidizing volatile reducing substances, chiefly sulfurous acid. The product was made acid with sulfuric acid and distilled in a current of steam until the distillate coming over no longer reacted acid. The
