T H E JOURNAL OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
1160
..
.
.
o:ii
None
0.46
None
..
99 82
.. ..
Node
1001
.. .. ..
..
By difference.
seem safe t o draw definite conclusions without further confirmation. TABLE 111-WITH
................
......
.........
.......... ......... .............. .............
..................... .......... ................. ........................
r Nickel Silver.. Nickel
TABLE IV-WITH
10' BB. SULFURIC ACID PK------Without * With Time FormalFormalMin. dehyde dehyde 3 0,007 0.001 0,010 60 0.190 0.007 0,0025 2 0.301 0.039 0.036 0.004 0,063 0.004 0.001 0,008 0.001 0.002 0.001 0.002 0.001 0 .'do3 0.003 0.001 60 0.0007 60 0 :0000 0.002 480 0.001
__
MATERIAL Wrought I r o n . . Wrought Iron.. . . . . . . . . . . . . . . . . Cast Iron... . . . . . . . . . . . . . . . . . . Cast Iron.. Steel A . .
Decrease Per cent -86 -95 -65 -87 -89 -98 -88
.. ..
.. .. ..
HYDROCHLORIC ACID (1 : 1)
T------K-
MATERIAL Wrought I r o n . . ............... Wrought Iron. Cast I r o n . . Cast I r o n . . Steel A , . Steel B . . Steel C . . Brass. Admiralty Metal.. Manganese Bronze.. Manganese Bronze.. . . . . . . . . . . Tin Tin .......................... Solder. ...................... Solder. Nickel..
................ .................. .................. ..................... ..................... ..................... ....................... ............ ..........
..........................
...................... .....................
Without Time FormalMin. dehyde 0.010 0.026 15 2 0.018 0.111 60 0.037 60 0.032 60 0.009 60 0.0025 480 480 0.0015 60 0.001 480 0.003 60 0.002 480 0,007 20 0.002 60 0.003 480 0.007
With Formaldehyde
0.002 0.001 0.002 0.001 0.005 0.001 0.008 0.0035
Increase or Decrease Per cent -50 -8 1 -72 -3 2 -87 -8 1 -5 5
.. .. .. ..
+16i -50
NITRIC AcID-Table v shows the results of the tests with I O per cent nitric acid. The results with this acid are in some cases rather contradictory. I t seems probable t h a t there may be some reaction between the formaldehyde and nitric acid or nitric oxide, TABLEV-WITH
10 PER CENT NITRIC ACID
-----K-
MATERIAL Wrought I r o n . . Cast Iron.. Cast Iron.. .................. Steel A , . Steel B . . Steel B . . Steel C . . ..................... Steel C . ...................... Brass. ....................... Admiralty Metal.. Admiralty Metal.. Manganese Bronze.. Manganese Bronze.. Copper. Copper. Lead. Lead. Tin. Tin. Solder. Solder. Nickel Silver.. Nickel. Nickel.
..........
............. ..................... ............. .............
............ ............ .......... .......... ...................... ....................... ........................ ........................ .........................
......................... ...................... ...................... ................ ...................... ......................
12,
NO.
12
.
TABLEII-XON-FSRROWS METALS(INPER CENT) cu Fe Pb Sn Zn 61.03 0.17 0.37 0.21 38.221 0.03 1.04 27.351 0.09 0.60 41.24' 49.11' 50.57 54:49 0.ii 26:631
MATERIAL
1
Vol.
Without Time FormalMin. dehyde 5 0.248 3 0.158 . 20 0.298 60 0.572 2 0.096 10 0.352 2 0.157 5 0.237 480 0.090 60 0.004 480 0.110 60 0.012 480 0.244 60 0.049 480 0.120 30 0,119 480 0.249 60 0.086 120 0.153 20 0.181 60 0.217 60 0.010 60 0.007 480 0.028
With Formaldehyde 0.152 0.013 0.212 0.566 0.083 . 0.275 0.136 0.134 0.028 0.002 0.248 0.001 0.122 0.009 0.103 0.127 0.241 0.052 0.138 0.125 0.421 0.001 0.005
0.004
Increase or Decrease Per cent -3 9 -92 -29
Mn
Sb
..
.. ..
0:6l
o.ji
Ni
.. .. ..
18'.'61
..
.. ..
Ndde
98.'80
..
As
.. .. ..
.. .. .. .. Ndde
nite conclusions can be drawn,the reactions with this acid need further study under careful temperature control. A Q U A REGIA-A test was made with dilute aqua regia upon wrought iron with t h e following results: -K--------Wrought iron..
..
Time Min. 60
Without Formaldehyde 0.039
With Formaldehyde 0.009
Decrease Per cent -77
The presence of formaldehyde appears t o decrease the effect of dilute aqua regia upon wrought iron. PRACTICAL APPLICATION
Recently there were submitted t o this laboratory samples of rusty steel rods which it was desired t o free from the rust without hurting the underlying steel. When the rods were treated with I : I muriatic acid containing about I per cent of formaldehyde, the rust was completely removed without any visible pitting of the steel. SUMiMARY
The above tests were carried out principally t o learn whether the presence of a small amount of formaldehyde in various acids would have a marked effect in decreasing their solvent action upon steel, iron, and other metals. The results show t h a t the presence of I per cent of formaldehyde in a 10' BB. sulfuric acid solution and also in a I : I hydrochloric acid solution decreases the solvent action of these acids upon wrought iron, cast iron, and steel t o a remarkable degree. The effect in the case of the other metals tested was not sufficient t o be important for the purposes of this investigation. The effect is less marked with I O per cent nitric acid, possibly on account of secondary reactions. The use of muriatic acid containing about I per cent of formaldehyde affords a convenient means of pickling rusty steel without appreciably affecting the surface of the steel itself.
..
-14 -22 -13 -43 -69 -33
+126 -9 2 -50 -9 2 -6
.. ..
-40 -10 -3 1 +94 -90 -30 -86
thus introducing a disturbing factor. Another difficuky with this series of tests was t h a t t h e reaction in some cases was rather violent, causing a heating of the In' the presence Of seems t o retard the action of the acid, but, before defi-
THE ACID HYDROLYSIS OF SUGAR-CANE FIBER AND COTTONSEED HULLS1 By E. C. Sherrard and G. W. Blanco FOREST PRODUCTS LABORATORY, u. s. DEPARTMENT OF AGRICULTUR~, MADISON,WISCONSIN
I n connection with the investigations of the Forest Products Laboratory during the war upon the preparation of ethyl alcohol from wood, i t became desirable t o apply the same treatment t o sugar-cane fiber and cottonseed hulls. Although these waste materials contained a relatively large _ proportion _ ~ of cellulose, i t was found t h a t only a small quantity of fermentable sugar was formed by hydrolysis, and that xylose constituted the largest part of the sugars thus produced. 1 Presented before the Division of Industrial and Engineering Chemistry at the 60th Meeting of the American Chemical Society, Chicago, Ill., September 6 t o io, 1920.
.
Dec.,
1920
. THE JOURNAL
OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
S U G A R - C A N E FIBER
Previous investigators have obtained xylose from this material by first extracting with a dilute alkali and then hydrolyzing the extract with a dilute acid a t atmospheric pressure. H. C. Prinsen-Geerligsl has thus obtained 3 0 per cent xylan, which upon hydrolysis with dilute acid yielded 79 per cent of sugar, a part of which was xylose. Since crystals of this sugar gave a specific rotation of +zoo, he concluded t h a t “probably some other sugar with a higher rotatory power was present, perhaps arabinose or d-glucose, resulting from the hydrolysis of the cellulose.” C. A. Brownez used the same method and obtained a yield of cane gum corresponding t o 25 per cent of the original fiber. This upon hydrolysis with dilute acid yielded 27.61 per cent of its weight of xylose. Based upon the dry weight of the original fiber, this would correspond t o a yield of 6.68 per cent. The latter figure represents the quantity actually obtained as crystalline xylose and is necessarily lower t h a n the actual yield. He was also able t o show the presence of a small quant i t y of arabinose in the mother liquor remaining after the isolation of the xylose. The present investigation deals with the direct hydrolysis of crude bagasse, using the method and apparatus previously employed for the study of the hydrolysis of wood.3 The process consists of digesting 2 j t o 1 0 0 lbs. of the material in a rotating digester with 1.8 t o 2.5 per cent of sulfuric acid for 1 7 t o 50 min. a t a pressure of from I O O t o 1 2 5 lbs. After blowing off t o atmospheric pressure the material is centrifuged and t h e remaining sugar extracted in leaching towers. The liquors are then mixed, the acid neutralized with calcium carbonate, and the whole evaporated t o a liquor suitable €or fermenting, i. e . , a solution having a sugar content of 5 t o 7 per cent. The total reducing sugars thus produced are determined by means of Fehling’s solution. The copper oxide formed is redissolved in nitric acid, and the copper deposited electrolytically. The sugar yields from cane fiber produced in this way are comparable with those obtained from a similar treatment of coniferous wood; in fact, they are somewhat greater than those obtained from a standard wood such as longleaf pine or white spruce. I n view of the fact t h a t bagassecontains from 5 0 t o 5 5 per cent of cellulose, one would expect the formation of considerable quantities of fermentable sugar when subjected t o a digestion under the above conditions;. Such, however, was not t h e case; the average of nine fermentations showed only 24.16 per cent of fermentable sugar as determined from the quantity of sugar removed, and of this only 50 t o 60 per cent was obtained as alcohol. T h a t the presence of hydrolytic products did not interfere with the action of the yeast during fermentation was demonstrated by fortifying the liquor with pure molasses such as was used in the propagation of the yeast. Here the fermentation took place seadily and with a n alcohol yield commensurate with the quantity of molasses added. “Observations in Bagasse,” Sugar Cane,30, 91. J . A m . Chem. Soc., 26 (1904),1221. 8 Kressman, THISJOURNAL, 7 (1915), 920.
1161
When i t was found t h a t the fermentable sugar constituted a relatively small portion of the total sugars, an effort was made t o isolate and identify the nonfermentable reducing substances. The attempt, however, was not successful, since the large quantities of gum in the liquor prevented the crystallization of t h e sugars, although every means was utilized t o clarify and purify this liquor. I n order t o obtain a liquor from which crystals could be obtained resort was had t o Hudson’s method for the preparation of xylose from corncobs.l One hundred grams of bagasse having a moisture content of 7.48 per cent were first extracted for 24 hrs. a t room temperature with 3 1 2 0 cc. of a 2 per cent solution of ammonium hydroxide. The ammoniacal liquor was then pressed out and the residue washed with cold water. The ammonia extraction removed 1 5 per cent of the original dry material. This extract after acidification did not reduce Fehling’s solution. It was then hydrolyzed by boiling with a 4 per cent solution of sulfuric acid, but still no reduction of Fehling’s solution was noted. Upon evaporation the ammoniacal liquor deposited a hard, brittle residue. ’ The extracted cane fiber was then digested with 2 liters of 7 per cent sulfuric acid for 2 hrs., pressed, washed, and dried. This treatment removed 35.8 per cent of the residue remaining from the ammonia extraction. The total reducing substances present in this acid liquor corresponded t o 21.22 per cent of the original dry fiber. After neutralization and clarification, the liquor was evaporated under reduced pressure t o a thick sirup, and crystallization started by the gradual addition of 9 5 per cent alcohol. Two crops of crystals were obtained from this liquor, both of which showed a melting point of 139’ and gave osazones which melted a t 160O and 15gO, respectively, and formed the characteristic boat-shaped crystals of the double salt of cadmium xylonate and bromide. The crystals were strongly multirotatory and showed specific rotation of +18.2”. I n all, 11.2 g. of pure crystals of xylose were obtained. This is equivalent t o 12.1 per cent of the original dry fiber, or t o 57.0 per cent of the total sugar determined by means of Fehling’s solution. No doubt the mother liquor contained much more xylose, although all efforts t o produce further crystallization were futile. Due t o lack of time the mother liquor was not investigated further. COTTONSEED HULLS
Cottonseed hulls were subjected t o the same high pressure treatment as was bagasse, and the same difficulty was encountered in obtaining crystals from the liquor. I t will be noted in Table I t h a t the sugar determined by means of Fehling’s solution is much less than was obtained from bagasse. This is due t o the hard, brittle nature of the material and the difficulty of penetration. T h a t the penetration is small is shown by the fact t h a t the digested material contained only 56.89 per cent of moisture after a So-min. cook. Here again little or no fermentation took place when the liquor was seeded with a pure yeast culture. 1
J Ant. Chem S o c , 40 (1918),1601.
