Kovember, 1932
I N D U S T R I A L A N I) E N G I N E E R I N G C H E RI I S T R Y
dene, the latter accounts for 1.8 to 4 times as much gum as does the former. Satural gums are contaminated with leather and iron oxide. The nitrogen and ash contents have led to the assumptions that the gums are products of oxides of nitrogen and also that they are salts of organic acids. Neither type of compound is an essential constituent of liquid-phase gum. Mercaptans and phenols are strong positive and negative catalysts, respectively, for the polymerization and oxidation of styrene and indene, and hence for the formation of liquidphase gum. Both classes of compounds are naturally present in certain types of manufactured gas. Their relative quantities affect the quantity of gum formed, particularly in mixed gas. The absence of liquid-phase gum in systems distributing coal gas and coke-oven gas under a thermal standard is due to the fact that such gas does not contain a sufficient quantity of styrene and indene to form the oily condensate which is the first step in the formation of this type of gum. Subsequent papers will deal with methods of preventing or reducing the formation of liquid-phase gum in gas distribution systems.
1247
LITER.4TURE C I T E D
Benzole Research Committee, Repls. 4-7 (1927-31). Berkhoff, Het Gas, 51. 460 (1931). Brooks, IND.EXG.CHEW, 18, 1198 (1936). Brown, Am. Gas Assoc. Proc., 1922, 1360-1. Brown, Ibid., 1922, 1366. ( 6 ) Brown, Ibid., 1924, 1360, Table 4. (7) Cassar, IND. ENO.CHEM.,23, 1132 (1931). (8) Engler and Weissberg, “Kritische Studien iibcr die Vorgangen der Autoxydation,” Braunschmeig, 1904; Stobbe and Pasyak, Ann., 371, 259 (1909); Milas, Proc. Nat. Acad. Sci., 14, 844 (1928), and J. Am. Chem. Soc., 52, 739 (1930); Houtz, Ibid., 53, 1058 (1931) ; Staudinger and Lautenschlager, Ann.,
(1) (2) (3) (4) (5)
488, 1 (1931). (9) Fieldner, e t al., Bur. Mines, Monograph, 4 (1931); Hola, Gas AgeRecord, 66, 341 (1930). (10) Fulweiler, Am. Gas Assoc. Proc., 1921,564. (11) Milas, Chem. Reo., 10,294 (1932); Thomas, J. Inst. Petroleum Tech., 18,357 (1932); Walther, Erddl u. Teer, 8 , 223 (1932). (12) Moureu and Dufraisse, Compt. rend. (1922-5); Chem. Rev., 3, 113 (1926). (13) Staudinger, Ber. and Helv. Chim. Acta (1929-31). (14) Ward, Jordan, and Fulweiler, ISD.ENO.CHEM.,24,969 (1932). (15) Watson, Gas J., 196, 620 (1931). (16) Yule and Wilson, IND.ENO.CHEM.,23, 1254 (1931). RECEIVEDJune 30. 1932.
A Factor in Rosin Coloration J. A. HAIL, Forest Products Laboratory, Madison, Wis. of very reactive nature which EMMLER (3) suggested Oleoresin of the southern turpentine pines confains soluble in water, probably secreted are probably secreted with the the possibility that oleoresinous constituents of gum. Their removal r e s u l t s with the oleoresin. These substances are very the production of r o s i n of plants were translocated in the susceptible to ocidation at lower temperatures and lighter color. plant in the form of glucosides decomposition at higher temperatures. Their reor ether-like compounds of a h EXPERIMENTAL PROCEDURE hols and sugars. The researches moval f r o m the gum by simply washing during For the Purpose of this inof Fromm (1)and of Neuberg (2) steam distillation results in rosins of considerably vestigation, 90 kg. of oleoresin, upon the fate of terpenes and lighter color, or gum, of the slash pine (Pinus camphors in the animal organism caribaea M o r e l e t ) w e r e proshowed clearly that they were excreted in combination with glucuronic acid. Certain oleo- cured from the Timber Products Company a t Cogdell, Ga. resins, particularly those of the draucarim, have been shown to This material had been collected with unusual care, and in contain gums and sugars along with terpenes and resin acids. consequence was clean and remarkably free from chips and These and other biochemical considerations rendered advisable foreign matter. The gum was subjected to distillation with an investigation of the water-soluble constituents of the oleo- steam a t atmospheric pressure and the condensed water was resin of the turpentine pines of the South, in connection with allowed to accumulate in the still. Under the conditions the the work of the Forest Products Laboratory on the biochem- agitating action of the current of steam caused a thorough washing of the gum. istry of oleoresin production. The water solution accumulated by this process amounted The French have long removed the free water from pine oleoresin by melting the material by some means-free flame, to about 80 liters. It was evaporated to 20 liters in a steamjacketed steam, or live steam, and decantation. This re- heated still and then to 2 liters over a flame. During this moves extraneous water-soluble material, but, if there are process a considerable quantity of insoluble grayish material present water-soluble physiological substances secreted with was formed, which further decomposed into a dark, gummy the oleoresin, it is clear that a thorough washing only would material soluble in alcohol. The clear filtered solution was further evaporated under remove them. Further, the radical difference in the chemical characteristics of the water-soluble material extracted from diminished pressure with carbon dioxide entering the flask pine chips and bark and that described in this paper as ex- through the capillary. At a volume of 250 cc. the solution tracted from slash Dine oleoresin, furnishes a strong me- gave the following reactions: sumption that the water-soluble material extracted frok‘the - A strong of solution. oleoresin by thorough washing is secreted with the gum, and 2 . xoprecipitate with normal lead acetate. has nothing to do with extraneous material. 3. A precipitate with basic lead acetate. 4. A grayish precipitate with ferric chloride, having no tannin It is not the purpose of this paper to enter into discussion of the chemical nature of the water-soluble constituents of C o ~ ~ ; r e c i p i t a t with e barium hydroxide solution upon the pine oleoresin. This complex problem is under investiga- addition of alcohol. tion. It is desired to point out that there are present bodies 6. Dark coloration with the usual pentose reagents, as
S
reduction
1248
INDUSTRIAL AND ENGINEERING CHEMISTRY
naphthoresorcinol and phloroglucinol, but not typical uronic acid reactions. It contained about 5 grams of solid material in solution. After precipitating a portion of the solution with basic lead acetate, filtering, and removing the lead from the filtrate with hydrogen sulfide, a barium salt was prepared by first making the solution alkaline with baryta and then adding 3 volumes of alcohol. After reprecipitation, a fraction of this salt, which contained 32.51 per cent barium, was obtained. Subsequently a larger quantity of the insoluble grayish material formed in the aqueous extract was obtained. This is insoluble in all ordinary solvents. It is soluble in dilute alkali and is precipitated from this solution upon acidification. This precipitate is of entirely changed character, being now dark brown and soluble in alcohol. The alcoholic solution is highly colored even at great dilution. The nature of this substance and the series of changes it undergoes are evidently complex, but it is certain that its precursor exists in the oleoresin in water-soluble form. The exact composition of this material must await the examination of much larger quantities and will probably form the substance of a subsequent paper. It seems to be fairly well established, however, that there are present in the oleoresin, bodies of an acid and carbohydrate nature which are susceptible to oxidation a t ordinary temperatures and further decomposition a t higher temperatures. The importance of this fact in rosin manufacture is that distillation processes now in use involve conditions that favor the decomposition of such bodies and consequently increase the dark color of the rosin produced. I n both fire stills and steam stills, distillation is carried out a t temperatures well above the atmospheric boiling point of water during the major part of the distillation. At the finish the high temperatures (150" to 160' C.) necessary to insure complete dehydration and clear filtration of the rosin are exactly the conditions that bring about the decomposition of these water-soluble constituents of the gum. ils mill be shown, such decomposition is increased by previous oxidation of the water-soluble constituents of the gum, like that which takes place on a high turpentine face when the cup is a t a considerable distance from the freshly wounded surface.
DESCRIPTION OF G U M
1. Slash pine, very clean 2.
Slash pine, dirty
3.
Longleaf pine, very clean
4.
8.
Longleaf pine, very dirty a n d heavily oxidized Slash pine, very dirty and heavily oxidized Longleaf Dine, dirty but not badly ox-idizrd Slash pine, dirty, b u t not badly oxidized Longleaf pine scrape, very clean
9.
Slash scrape, dirty
5. 6.
7.
VOl. 24. No. 11
GRADE O F ROSIX~Q Unwashed, WG Washed, W W Unwashed. M Washed, W W t o WG Unaashed, W W Washed. X (about two grades lighte; than 'X) Unwashed, B Washed, B Unwashed, G Washed, I Unwashed. hl Washed, N Unwashed, WG Washed, WW Unwashed, i X W hed W .. a q .._-, .. C Unwashed. M Washed, N S. standard rosin types I n order are X, WW, WG, N, M, K , I, H,
+
The rosins were graded against U. of increasing depth of color, the grades G, F, E, D, B.
-"
-
Gums 4 to 9 were collected by the Southern Forest Experiment Station a t Starke, Fla., and an endeavor was made t o procure as dirty specimens as possible. Sample 4 was from rusty galvanized-iron cups and therefore contained a great deal of iron. No method was found for improving this gum. I n order to obtain a roughly quantitative idea of the effect of the water-soluble material on the color of the rosin produced, a sufficient quantity of gum 2 to yield 2400 grams of wet rosin was distilled and washed. The clear, filtered, practically colorless, aqueous solution so obtained was evaporated in uacuo with carbon dioxide in the capillary to 800 cc. The washed rosin gave JVW rosin upon dehydration a t 160" C. Dehydration runs a t 160' C. were then made in which weighed quantities of wet rosin were dehydrated with varying quantities of the aqueous extract of the gum. Seventy-five cubic centimeters of the extract corresponded to 225 grams of the wet rosin. The following runs were made: RUN 1 2 3
ROSIN Grams 225 225 225
AQCEOUS EXTRACT Cc. (equzEa2ent) 75 (1) 150 (2) 225 (3)
GRADEOF ROSIN OBTAINED
N K I
The remainder of the clear, colorless, aqueous solution was oxidized by bubbling a slow stream of air through it for 4 hours. It developed a finely divided precipitate having the EFFECTOF REMOVAL OF WATBR-SOLUBLE PORTIOS OF GUM grayish color characteristic of much commercial gum and similar to that described before. A brief study has been made of the effect upon rosin color One equivalent of this suspension, added to the same JVW of the removal of the water-soluble portion of the gum. rosin previously used and dehydrated exactly as before, gave Preliminary attempts to wash the gum through violent M rosin; two equivalents gave I rosin. Thus two equivastirring in cold water were futile because of its high viscosity. lents of the oxidized extract were equal in coloring power to When this factor was removed by washing a t 90' C., the in- three equivalents of the unoxidized. corporation of air into the gum through stirring while hot caused oxidation and the resulting rosins were dark. DISCUSSION OF RESULTS Advantage was then taken of the fact that, in ordinary I n all but one sample examined, a definite improvement steam distillation, the current of steam causes good stirring of the gum a t 100" C., and, if sufficient water is allowed to in color was obtained by simply washing with hot water. accumulate in the distilling flask, an excellent washing is ob- With the one exception, the iron content prevented any such tained without oxidation. This water, decanted twice during improvement. The improvement was due to the removal of a distillation, removes practically all water-soluble constitu- water-soluble materials that, under the conditions of dehydraents. The rosin, containing emulsified water, was dehydrated tion of the rosin, would normally cause development of color. in a paraffin bath a t 160" C. and filtered through cotton bat- Oxidation of gum before distillation renders insoluble in water a portion of the otherwise water-soluble material. It seems ting between muslin cloths. Check runs were made in much the same manner, except likely also that oxidation increases the color-forming capacity that the accumulation of water in the still was prevented by of the soluble material. The effect of oxidation on color was immersing the flask in a bath a t 120" C. Dehydration was noted in 1902 by Vezes (G), but the mechanism has been carried out as it had been with the washed rosin. The treat- thought to be only one of combination with the resin acids. ment and dehydration of 250 grams of gum required from 2.5 Such combination is doubtless also a n important factor in rosin coloration. to 3 hours. The importance of iron in rosin coloration has been pointed For further verification of the results obtained, an additional number of samples of gum differing widely in character out by Veitch and Smith (4). The production of uniformly were obtained and distilled, n i t h and without washing. The pale gum rosin depends upon the following factors: (1) low exposure of gum to oxidation, (2) use of apparatus free from results were as follows:
November, 1932
I N D U S T R I A L A N 13 E N G I N E E R I N G C H E M I S T R Y
exposed iron, (3) controlled temperatures of distillat ion, and (4) provision in rosin manufacture of means for remclving the water-soluble portion of the gum. The first three faciors have long been known and practiced, but the fourth has hitherto received little or no attention. Possibly a fifth factor-filtration of the gum before distillation-should be added. I n the present experiment., howerer, washed strained roiins and washed unstrained rosins gave exactly the same colors upon dehydration. The removal of suspended dirt is rssential; this is necessary for considerations other than color. It seems probable, therefore, that a combination in manufacture of an efficient gum-cleaning device n-ith a steam still properly
1249
designed for washing the rosin should give the highest grades of rosin. LITERATURE CITED (1) Fromm, 2. physiol. Chem., 33, 579-94 (1900). (2) Neubera, Ibid., 44. 114-26 (1903). (3) Semmler, “Die aetherisohen Oele,” Vol. 1.pp. 12-13, Veit & Co., Leipzig, 1906. (4) Veitch and Smith, S a v a l Stores Rev., 38, S o . 46, 18 (1929). ( 5 ) Vezes, M., Report de la laboratoir de chimie applique a I’industrie des resines, Bordeaux, 1902-3.
RECEIVED April 7, 1932. Presented before the Division of Agricultural and Food Chemistry a t t h e 83rd Meeting of the American Chemical Society, New Orleans, La., March 28 t o April 1, 1932.
Bagasse Cellulose D. F. ;r. LYKCHAND M. J. ~ o s s Bureau of Chemistry and Soils, 1.;. S. Department of Agriculture, Washington, D. C .
T
HE past few years have witnessed a stupendous
An analytical study of the cariety of bagasse available is made to determine some commercial use for the by-product. The comparatively high crude-fiber content would indicate that bagasse m a y be used as a source f o r cellulose. The optimum conditions are determined f o r the production of cellulose f r o m bagasse by the soda method, the sulfate method, and the neutral sulJite method. Experiments indicate that by rigid control of conditions slightly higher yields of cellulose cafi be obtained than those previously reported. The neutral suljite digestion gives slightly higher yield than the other methods tested. Becauc;eof the poor recovery of the cellulose present in the bagasse, a study of the nitric acid pulping process is made with this byproduct. Under the optimum conditions higher yields and better cellulose are obtained W i t h this process. Owing to the oboious adcantages of this process and the probability of cheap nitric acid f r o m the oxidation of ammonia, there are indicated commercial possibilities of using the yearly supply of 250,000 to 500,000 tons of bagasse as a source for a-cellulose.
growth in all the cellulose industries of this country. The raw cellulose needed by any one of the younger cellulose industries is small in comparison with the pulp demanded in our p a p e r production. Together, hov-ever, these younger industries u t i l i z e a c o n s i d e r a b l e amount of cellulose, and they require a higher grade of oellulope than that found satisfactory by our paper manufacturers. Those manufacturers using nitrated c e l l u l o s e and the producers of cellulose acetate are dependent, a t the present time, for their raw material on cotton linters. The viscose rayon process, which supplies over 80 per cent of the world’s production of rayon, employs, however, for the bulk of its cellulose supply, high-grade wood pulp prepared from spruce wood. Other cellulose processes -for example, the production of a b s o r b e n t c~ellulow--are each year taking larger amounts of high-grade wood pulp. The fear that the northern foIests may some day be insufficient t o supply these increasingly cnormous amounts of cellulose, together Tvith the fact that thehe forests are yearly receding from the cellulose markets with increasingly higher freight charges. have directed considerable attention to the possibility of increasing the range of raw materids available for these important industries. Many of our crop wastes naturally suggest themselves as possible sources of crude cellulose. To merit attention, however, the crop waste must be arailable in large volume at low cost. One important item of expense that i. usually encountered is the cost of collection. This cost, if high, may preclude further serious consideration of the material. -2 waste product already collected in the marketing of some main product is, therefore, desired. One product that meets theqe requirements is bagasse. There are collected and
available each year a t the sugar mills in continental United States between 250,000 (1-4)and 500,000 ( I O ) tons of bagasse. Bagasse is not, however, a waste product. It is used as a fuel a t the sugar mills and in the production of insulating and building board.
COJIPOSITION OF BAGASSE For many years bagasse has come under the scrutiny of the sugar chemists. The strenuous competition in t h e sugar industry has d e m a n d e d that each sugar mill remove from the cane p r a c t i c a l l y all the economically available sugar. To i n s u r e this end, rigid control work has t o b e m a i n t a i n e d on the bagasse before it can be discarded. The usual absence of cheap fuel in cane-growing areas has also served to direct the attention of e n g i n e e r s to the use of this waste as a fuel. Doubtless, t h e r e f o r e , t h e r e exists a large amount of unpublished analytical 1%-orkon this by- p r o d u c t , Considering the large number of varieties of cane,the many different locaiities from which it is harvested, and the nature of the material, there is exhibited good agreement in the published analytical results. From the results in Table I i t is safe to assume that the cellulose content of moisture-free bagasse will average onehalf its weight. Air-dried bagasse has been reported to contain 8.3 per cent of moisture by Kumagawa and Shimomura ( I S ) , 10.8 per cent moisture by the Imperial Institute Laboratory ( I ) , 10.3water hy S’alenzuela and West (sa),and, on the samples available, has been found by this laboratory to range from 9.9 to 12.5 per cent.
RAWMATERIAL When all the sugar has been extracted from the cane, the green bagasse, containing 45 to 55 per cent water, is dis-
.
