November, 1929
INDUSTRIAL AND ENGINEERING CHEMISTRY
g = main body of gas k = interface between gas and liquid films L = main body of liquid ?1p = molal units pe) = weight units w = volume units 0 = standard conditions, TO= 273” K., P~ = 1 atmosphere absolute av. = arithmetic mean
Pressures: p = partial pressure, atmospheres absolute P = total pressure, atmospheres absolute Concentrations: C = concentration of solute in liquid, expressed a s grams per cc. Rates per Unit Interfacial Area: N A = gram mols of s d u t e per hour per sq. cm. W A = grams of solute per hour per sq. cm. U A = CC. of solute gas per second per sq. cm., a t actual T and K (gram mnls of solute)(cm. thickness of film) (hour) (sq. cm. of interface)
(cc. of s d u t e gas) (cm. thickness of film) (second) (sq. cm. of interface) P (k,), = value of kv a t standard conditions, T = TO, (grams of solute) icm. thickness of film) k, = (hour)(sq. cm. of interface)
k.
F,,FL = over-all coefficients for Equations I b and I C Miscellaneous: b = empirical constant d = prefix indicating differential of suffix d,, = inside diameter, cm. D = inside diameter, inches M = molecular weight R = gas constant in Lewis-Chang equation T = absolute temperature, OK. v = average mass velocity of gas mixture, expressed as grams per second per sq. cm. of cross-sectional free area V = average mass velocity of gas mixture, expressed as lbs. per second per sq. ft. of cross-sectional free area p = viscosity of gas mixture in poises = (gram)/(second)(cm.) Z = viscosity of gas mixture in centipoises = 100 times absolute viscosity expressed as (gram)/(second)(cm.) a = specific resistance term in Lewis-Chang equation; CL = RT/k,M..iiVB 6 = a function L i t e r a t u r e Cited
Specific Diffusion Coejicients: krn
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=
= ro
Film Coefficients: (grams of solute) = k,/x (hour)(sq. cm. of interface) (grams of solute) = -. kto a (hour)(sq. cm. of interface)(atm.) z(~B),,
’‘ ’‘
(1) Greenewalt, IND. E N G .CHEM., 18, 1291 (1926). (2) Haslam, Hershey, and Kean. I b i d , 16, 1224 (1924). (3) Haslam, R y a n , and Weber, Ibid., 15, 1105 (1923). (4) Jeans, “Dynamical Theory of Gases,” p. 334, Cambridge University Press. (:5) Landolt-Bornstein, Tabellen, 1923, p p , 172, 176, 250. (6) Lewis a n d Chang, Trans. A m . Inst. Chem. Eng.,21, 127 (1928). (7) Lewis and Whitman, IND. E N G . CHSM.,16, 1215 (1924). ( 8 ) hfaxwell, Phil. M a g . , 20, 21 (1860); 35, 109 (1868). (9) McAdams and Frost, IKD.E N D . CHEM., 14, 1101 (1922). (10) Sherwood. Ibid., 17, 745 (1925). (11) Stefan, Ber., 68, 385 (1873); A n n . Physik, 1890, 725; Silzb. Akod. W’ien, 1873, 403. (12) Whitman, Chem. Met. Eng., 29, 147 (1923). (13) Winkelman, Handbuch der Physik, Vol. I , p. 1405, J. A. Barth, Leipzig, 1908,
Production of Acetic and Lactic Acids from Mill Sawdust’ R. J. Allgeier, W. H. Peterson, a n d E. B. Fred DEPARTMEKTS OF AGRICULTURAL CHEMISTRY A N D AGRICULTURALBACTERIOLOGY, UNIVERSITY OF WISCONSIN, MADISON,WIS.
I
N A PREVIOUS paper (6) it was shown that the pentoses remaining after the alcoholic fermentation of rn ood-sugar liquor could be fermented by bacteria with the production of lactic and acetic acids. From a n economic point of view it should be decidedly advantageous to follow the alcoholic fermentation with this bacterid fermentation and thus utilize sugars which are not fermented by the yeast and which amount to about 35 per cent of the total sugars obtained from wood. These pentose-fermenting bacteria can be used, not only to supplement the action of yeast, but also directly to ferment the wood sugars. It was found that about 90 per cent of the total wood sugars were fermented by the bacteria and that practically all of the fermented sugar was recovered as acetic and lactic acids. It is obvious that there are powibilities here of utilizing wood waste and other materials for the production of useful chemicals. In the following investigation a n effort has been made to use the mill run of sawdust, to increase the concentration of products, and to determine the fermentability of wood sugar produced by different methods of hydrolysis. Various other 1 Received August 14, 1929. Presented before t h e Division of Industrial and Engineering Chemistry a t t h e 78th Meeting of the American Chemical Society, Minneapolis, hlinn., September 9 t o 13, 1929.
factors, such as time of fermentation, effect of temperature, and methods of neutralizing the acids as they are formed, have also been studied. P r o d u c t i o n of Sugar by Different M e t h o d s of Hydrolysis
The production of sugar by the hydrolysis of wood waste has been studied by numerous investigators ( 2 , S, 5 , 8). The present investigation is concerned primarily with the fermentation of nood-sugar liquors obtained by various methods of hydrolysis rather than a study of the conditions of hydrolysis. The mills from which the sawdusts were obtained and the chief kind of wood in ea(h of thwe sawdusts are given in Table I. The conditions of hydrolysis and the resultant yields of sugar are given in Table 11. In all but two instances sulfuric acid was used as the hydrolyzing agent. By a single hydrolysis yields of sugar ranging from 11.3 to 19.3 per cent of the dry wood were obtained. A second treatment of the residue from the first hydrolysis netted additional yields of from 3.9 to 7.6 per cent and gave a total in one sample (cook 6) of 26.0 per cent. These figures are presented, not mith the idea that they represent industrial yields-the latter are known to give higher results-but merely to show that we have
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INDUSTRIAL AND EhlGINEERING CHEMISTRY
Vol. 21, No. 11
dealt with wood-sugar liquor of approximately the same type as would be obtained on a plant scale. An attempt was also made to hydrolyze with 40 per cent hydrochloric acid and dry hydrochloric acid gas similar to the procedure of the so-called Rheinau and Prodor processes ( 7 ) . Although it is difficult to operate these processes with the ordinary laboratory equipment, a much larger yield of sugar was obtained by their use than by the sulfuric acid method.
This adaptation of the organism to high sugar concentrations proved to give the most vigorous inoculum. The data for ten typical small-scale (200-cc.) fermentations are shown in Table 111. These were chosen from numerous experiments in which the two organisms mentioned above were used. The results indicate that from 7 to 9.6 per cent concentrations of sugar may be fermented in about 9 days with a destruction of about 85 per cent of the total sugars and a yield of acid equivalerit to 95 to 100 per cent of the sugar destroyed. In other words, the sugar fermented Selection of a Satisfactory Organism is almost quantitatively recovered as products. Table I11 In a previous paper (6) it was reported that, after testing also shows that there is no difference in the fermentability a large number of cultures, one organism, No. 24-2, proved of the sugar liquors from the different woods. itself outstandingly superior' in the fermentation of woodIn the small fermentations (Table 111) the acid produced sugar liquor. S i n c e t h i s is approximately 90 per cent time 120 cultures of lactic lactic and 10 per cent acetic, acid-forming bacteria have but in the large fermentaCommercial mill sawdust (fir, spruce, and pine) was been isolated from various tions (Table IV) about 95 hydrolyzed with dilute sulfuric acid and the resulting sources-vjz. , sauerkraut, per cent of the total is lactic sugar liquors were fermented with a lactic acid orolive brine, pickle brine, and a n d 5 p e r c e n t is acetic. ganism which ferments both pentoses and hexoses. vegetable tissue. Most of A n a l y s i s of the zinc salt Malt sprouts (5 per cent) as a source of nitrogen and these organisms fermented showed that the lactic acid excess calcium carbonate as a neutralizing agent must less than 80 per cent of the is the inactive form. be added to the sugar liquor in order to bring about a sugar in a given fermentaPreliminary work i n d i satisfactory fermentation. tion, but one culture, No. cates that the sugar liquor From 7 to 10 per cent concentrations of sugar may be 20, of the same general charresulting from hard woods fermented in 5 to 7 days with a destruction of 82 to 88 a c t e r i s t i c s as No. 24-2, is not so readily fermented per cent of the total sugars. A yield of acid equivalent r e g u l a r l y gave fermentaas from soft woods. to 95 to 100 per cent of the sugar destroyed is obtained. t i o n s of 80 p e r c e n t o r The relation between the This acid consists of 90 to 95 per cent lactic and 5 to 10 concentration of sugar, the better. The work reported per cent acetic acids. speed of fermentation, and in this paper has, therefore, Sugar obtained by the Bergius process fermented the percentage of s u g a r been limited to these two equally as well as the sugar liquor obtained by the f e r m e n t e d are shown in strains of the same organsulfuric acid process and gave approximately the same 1. A 4.3 per cent Figure ism. yield of products. sugar concentration is alFermentation of Woodmost completely fermented Sugar Liquors in 2 days. Withhigher sugar The sugar liquor was leached from the undigested residue, Concentrations, 8 to 10.3 per cent, the speed of the fermentaevaporated to a Concentration of 12 to 15 per cent sugar, tion is somewhat slower, about 80 per cent being fermented and the sulfuric acid removed with calcium carbonate. Malt in 5 days. During the following 3 days only about 3 per sprouts (about 5 grams per 100 cc.) were added to the sugar cent more of the sugar is destroyed. The rate of fermentaliquor and after sterilization the medium was inoculated with tion of the Bergius product is essentially the same as that a suitaide culture. Several kinds of organic nitrogen were of the other wood-sugar liquor. tried, but malt sprouts proved to be the most satisfactory. Table 11-Production of S u g a r f r o m S a w d u s t They are also the cheapest form of nitrogen that can be (Calculated on d r y weight a t 100' C.) ACIDBY SUGAR AS utilized by the organisms. COOK WOOD WEIGHT PRESSURE TIME G L U C O ~ B SAMPLE 1 2 3 4
5
T a b l e I-Source a n d Kind of Mill S a w d u s t KINDOF WOOD SOURCE Fir Tidewater Mill Co , Tacoma, Wash. Spruce Pacific Spruce Corp , Toledo, Ore Short-leaf Sumter Lumber Co , Electric Mills, Miss yellow pine Fir Pacific Spruce Corp , Toledo, Ore Fir McKenna Lumber Co , McKenna, Wash
Fermentations of the wood liquor were conducted in the beginning on a small scale (200 cc.) and later on a much larger scale (10 to 14 liters). A 2 per cent inoculum of a 24-hour culture of the organism which had been grown in wood liquor of the same sugar concentration as the liquors to be fermented was used in the small fermentations and a 5 per cent inoculum was used in the larger fermentations. An excess of calcium carbonate was added and the flasks were shaken every 3 hours, except during the night, in order to effect a better neutralization of the acids produced. Incubation temperature was 28" C. unless otherwise specified. The inoculum for the higher sugar concentrations was built up by inoculating into a medium of about 2 per cent wood sugar and after 24 hours transferring successively to wood-sugar media of 4, 6, 8, and 10 per cent concentrations.
No.
Kind
Per cenl Pounds Minutes H901" 4.0 240 Fir 26 240 4.0 26 Spruce 240 6.0 20 Pine 240 4.0 26 Fir 240 4.0 20 Fir 15 115 2.5 Fir 15 115 2.5 Spruce 15 2.5 115 Spruce 15 2.5 115 Pine 2.5 15 115 Fir 2.5 15 115 Fir 240 23 Spruce 5.0 210 4.0 23 Spruce 240 5.0 23 Pine 210 4.0 23 Pine 240 5.0 23 4 Fir 210 4.0 23 Fir 4 5.0 240 23 Fir 5 210 4.0 23 Fir 5 iIL1 29c 2 Spruce 40.0 None .. 29d 2 Spruce 40.0 None .. a Three parts dilute acid t o 1 part sawdust by weight. b Second hydrolysis of previous cook. c After Rheinau plan. d After Prodor plan. 9 10 22 12 18 17 6 66 14 15 18 30 30 b 30 30 b 30 30 b 30 30 b
1 2 3 4 5 1 2 2 3 4 5 2 2 3 3
__-.
.
.
Per cenl 17.7 16.3 16.6 16.8 17.1 18.8 18.4 7.6 11.3 17.2 19.3 15.2 5.5 16.7 4.6 16.9 3.9 14.7 4.3 30.0 38.3
Fermentation of Bergius Product
Through the kindness of Professor Bergius a sample of the sugar produced by the Rheinau process was obtained from
INDUSTRIAL A N D ENGINEERING CHEMISTRY
November, 1929
the Holzhydrolyse Company, Heidelberg, Germany. This is a tetramer of glucose and must be hydrolyzed before it can be fermented. This was accomplished by hydrolyzing with 3.2 parts of mater to 1 part of the sugar a t 15 pounds (1 atmosphere) pressure for 30 minutes. By employing this method it has been possible to obtain a maximum of 88 per cent of reducing sugars based on the dry weight of the product. The fermentability of this wood sugar is indicated in Table V and Figure 1. It msy be seen that it is as readily fermented as the sugar liquors obtained by the sulfuric acid process. The products are the same and are formed in approximately the same proportions (Tables IV and V). These results are of special interest. If the yield of sugar from wood can be increased to 65 per cent, as reported by Bergius and his group (2, S), the yield of lactic and acetic acids can be increased proportionally.
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that the malt sprouts contain sufficient phosphorus for the needs of the organism. Table VI-Effect of Colloids a n d P h o s p h a t e s (Culture 24-2 used in all cases)
WOOD Kind No. 3 3
Pine Pine
3 3
Pine Pine
4 4 4 4
Fir Fir Fir Fir
NONVOLATILE VOLATILE SUGARST.GAR ACIOAS ACIDAS AS FERADDITIONSGLUCOSEMENTED TIME ACETIC LACTIC
Colloid None Willow charcoal Talc
Fuller's earth KiHPOi Per cent 0.0 0.2 0.4 0.8
Days
Per cent
Per ccnl
6.9
84.6
9
0 34
5.05
6.9 6.9
82.3 83.6
9 9
0.40 0 46
5 18 5 23
6.9
82.0
9
0 39
5.00
4.3 4.3 4.3 4.3
94.2 93.0 90.5 92.1
5 5 5
0.36 0.36 0.43 0.36
4.09 3.69 3.66 3.10
Per Len1 Per cent
5
Effect of Temperature and Time of Neutralization
WOOD No. Kind
Table 111-Fermentation of Wood Liquor (Small scale-200 cc.) SUGAR SUOAR VOLATILENOS-VOLAS FERACIDAS ATILE ACID CULTUREGLCCOSE MENTED TIME ACETIC AS LACTIC Per cenl
Spruce Pine Fir Fir Spruce Spruce Fir Spruce Pint: Fir
No.
WOOD Kind
24-2 24-2 24-2 24-2 20 24-2 24-2 24-2 24-2 20
2 2 2 2 4 5 6 6
86 24 49 64 10 00 00 20 6 90 9 60
Per cenl D a y s 93 91 93 92 88 92 91 88 84 83
Per cent
2 5 6 2 8 0 8 1 5 0
0 27 0 21 0 19 0 20 0 30 0 43 0 37 0 54 0 42 0 62
Per cent 2,l5 1.60 1.92 2.10 3.38 3.96 5.10 4.59 5.25 7 00
T a b l e IV-Fermentation of Wood Liquor (Large scale-IO t o 14 liters) SUGAR SUGAR VOLATILEXON-VOLAS FERACIDA S ATILE ACID CULTURE GLUCOSEMENTED TIMEb ACETIC A S LACTIC
Fermentations were carried on a t 28" and 3 7 O C. to ascertain the effect upon sugar destruction and speed of the fermentation. The effect of the time of adding the neutralizing agent, calcium carbonate, all a t the beginning or daily during the fermentation, was also studied. The data are summarized in Table T'II. It may be seen that similar results were obtained a t both temperatures. Destruction of sugar was followed daily (not shown in table) and the speed of the fermentation was approximately the same a t the two temperatures. I n all the experiments the cultures were shaken every 3 hours, except during the night. From the data it appears that the neutralizing agent may be added all a t the beginning, producing as good a fermentation as that with daily additions.
Per cenl Per cenl D a y s Per cent Per cent 24-2 8.0 88.5 10 0.38 6.68 6.66 24-2 and 8.0 86.5 10 0.36 20a 4 Fir 24-2 10.3 82.1 8 0.42 7.97 Bergius product 24-2 8.7 87.4 8 0.42 7.07 Mixed culture of two organisms. 6 SO+ per cent of sugar was fermented in 6 days (Figure 1)
2
Spruce Spruce
2
Q
of Wood S u g a r (Bergius Product) SUGAR VOLATILE NON-VOLATILE AS FERMENTED ACID ACID GLUCOSE I N 9 DAYS A S ACETIC A S LACTIC Per c e n t Per cent Per cenl Per cent
T a b l e V-Fermentation SUGAR CULTURE 20 20 20 24-2 20 24-2 24-2 and 20"
7.7 8.1 8.2 8.1 8.1 8.1 8.1
84.5 85.8 84.2 89.0 86.5 90.3 93.5
0.50 0.50 0.52 0.68 0.71 0.77 0.95
6.27 6.26 6.13 6.30 5.76 6.21 6,50
Mixed culture of two organisms.
Effect of Colloids and Phosphates
The stimulating effect of colloids upon various fermentations has been reported by several investigators (1, .4). The effect of certain colloids upon this fermentation was studied and the results obtained are given in Table VI. The extent of fermentation was followed periodically by determining the '1 ion acsugar remaining, and in no case was the fermentct' celerated. Since the malt sprouts remain partially suspended in the fermenting liquors, it is probable t>hatthey act as a colloid, and therefore the addition of any more colloidal material has no effect. The presence of phosphate has been shown to produce a favorable influence upon certain lactic fermentations (9). Table VI shows the results obtained by varying the phosphate (K2HP04) content from 0.2 to 0.8 per cent. Destruction of sugar was determined periodically, and in no case was the fermentation more rapid than the control. It is probable
~.
Figure 1-Effez
of Sugar Concentratio.1 on R a t e of F e r m e n t a t i o n
Table VII-Effect of T e m p e r a t u r e a n d T i m e of N e u t r a l i z a t i o n on F e r m e n t a t i o n of Wood S u g a r (Bergius Product) (Culture 24-2 used in all cases) NosSUGAR SUGAR VOLATILEVOLATILE TEXPERAAS FERMESTED ACIDA S ACIOA S T U R E TIMEO F ADDITION GLUCOSEI S 9 DAYS ACETIC LACTIC Per cent Per cenl Per cent Per cent c. 7.6 76.8 0.36 6.40 28 All at beginning 37 All at beginning 7.6 88.0 0.55 6.20 0.86 6.40 37 All at beginning 7.6 88.1 6.9 84.5 0.42 5 25 28 Daily 6 9 83.0 0.34 5.00 28 All at beginning 28 All at beginning 7.6 87.8 0.56 6.40
Commercial Applications
A digest of the results reported in the preceding tables is given on a ton basis in Table VIII. If industrial operations produced the same yields as ha\-e been obtained in the laboratory, from 316 t'o 950 pounds of lactic acid would be obtained per ton of drj. sawdust. These high yields are due to the unique property possessed by this organism of producing lactic acid from both pentoses and hexoses. If the numerous efforts being made to produce wood sugar on an
INDUSTRIAL A N D ENGINEERING CHEMISTRY
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industrial scale prove successful, the employment of this organism should be of value in the commercial utilization of such sugar. Yield of P r o d u c t s per Ton of D r y Sawdust H z S O I PROCESS HCI PROCESS Yield of sugar, pounds 400 1200 Sugar fermented pounds 340 1020 Concentration lactic acid in fermented liquor, per cent 7-8 7-8 Concentration acetic acid in fermented liquor, per cent 0.350.4 0'35-0 Lactic acid, pounds 316 950 Acetic acid, pounds 17 50 T a b l e VIII-Average
VOl. 21, No.11
Literature Cited (1) (2) (3) (4)
Abderhalden, Ftrmenfsforschrrnq, 6, 255; 6, 143 (1922). Eergiuz. Science. 68, 1768 (1928). Eergiur. Z . U R E P W . Chem., 41, 707 (1928). Grieg-Smith. Proc. Lznnean Soc. N . s. Wales, 60, 341 (1925); 61, 1% (1926,: 61, 17 (19271. (5) Hagglund. Papzer Fabrikanl, 24, 52 (1927). (6) Marten. Sherrard, Peterson, and Fred, IND. ENG.CHEX., I S , 1162 (I92 7 ). (7) Ormandy, J . SOC. Chem. I n d . , 46, 267T (1926). (8) Sheirard and Blanco. IND. ENG.CKEM..16, 611 (1928). (9) Virtanen, 2 gkysiol. Chem., 166, 21 (1927).
Effect of Small Quantities of Third Elements on the Aging of Lead-Antimony Alloys' Earle E. Schumacher, G. M. Bouton, and Lawrence Ferguson BELLTELEPHONE LABORATORIES, 463 WEST ST., NEW
I
N T H E lead-antimony system (1) there is a range of
compositions near the lead end in which dispersion hardening takes place. Lead and antimony form a simple eutectiferous system with a solubility of 2.45 per cent antimony in lead a t the eutectic temperature, 247" C., decreasing to 0.27 per cent antimony at 30" C. It is possible to harden the alloys in this range by quenching them from a temperature a t which the hardening constituent is in solid solution, and then aging a t room temperature to precipitate the dissolved eonst!ituent in a dispersed condition. A previous paper (3) by two of the authors shows that the normal rate of precipitation of the excess antimony is greatly modified by cold-working the alloys. In the present paper data are given t o show that the normal rate is also greatly affected by the presence of minute quantities of third elements. The particular third elements-arsenic, copper, silver, nickel, and manganese-chosen for study are those commonly found in different grades of commercial lead.2 Seljesater (3) has recently shown that arsenic in1 Received July 22, 1929. SThe effect of bismuth and some other elements and the effect of combinations of elements are now being investigated by the authors.
TIME OF ACING IN DAYS
Figure 1-Effect of S m a l l Q u a n t i t i e s of Arsenic on the Specific Resistance of 1% S b - P b Alloys
YOKK,
N.Y.
creases the rate and degree of hardening of lead-antimony alloys. Preparation of Alloys
The lead-1 per cent antimony base for the experimental alloys was made from a high-purity commercial lead and Kahlbaum's high-purity (99.97+ per cent) antimony. An analysis of the lead showed the following impurities: silver 0.0006, bismuth 0.001, antimony 0.003, iron 0.001, and tin 0.001 per cent. The lead was heated to from 500" to 600" C. in a graphite crucible in an atmosphere of hydrogen to prevent oxidation. In the preparation of each alloy the antimony was added before the third element. Arsenic was added to the lead antimony directly. The silver was first alloyed with a small pellet of lead on a charcoal block in a reducing flame, and then the resulting mixture was added to the lead. The copper, nickel, and manganese were added a t 600' C. in the form of the c. P. anhydrous chlorides. The chlorides melted and interacted with the lead, releasing the metallic third elements which dissolved in the melt and forming lead
TIME OF AGING IN DAYS
Figure 2-Effect of S m a l l Q u a n t i t i e s of Co per on the Specific Resistance of 1 % Sb-Pb AlEYS
