T H E J O U R N A L O F I N D U S T R I A L A N D ENGI2ITTEERlNG C H E M I S T R Y
Mar., 1921
-
1--2anetti and Egloffl have shown t h a t with increase in temperature above 800" C. t h e formation of t a r from benzene increases a t the expense of the diphenyl. This explains why the yield of t a r increased a t all, since t h e products of the reaction were mainly diphenyl and tar. 2-From Fig. 1 we see t h a t t h e per cent of decompbsed benzene increases with the temperature and becomes unity a t 925" C., t h e temperature a t which maximum yield occurs. I n other words, the increase in t a r formation is accompanied b y a n increase in decomposed benzene which becomes the total benzene a t 925' C. The variation of t a r a t once indicates a n increase in t h e yield of anthracene with increase in temperature. This is well supported b y the facts, as shown in Figs. 4 and 5. The formation of anthracene is negligible below 850' C., but increases quite rapidly until 925" C., and then drops sharply owing to the rapidly increasing predominance of the carbonization reaction. Owing t o the striking similarity between Pigs. 3 and 4 i t can be stated t h a t t h e conditions which favor t h e formation of t a r also favor the synthesis of anthracene.
21 I'
t o a heavy, greenish brown, fluorescent oil, and finally t o a black, viscous tar. At 925" C., t h e t a r had acquired a n appearance and viscosity t h a t was very similar t o t h a t of natural coke-oven t a r . There are numerous other compounds formed in this reaction which have not been investigated but which will form the subject of a further communication. SUMMARY
1-The formation of anthracene from ethylene and benzene has been studied a t temperatures varying from 800" t o 1000" C., and a t atmospheric pressure. 2-The optimum temperature has been found t o be 925" C. Above t h a t temperature t h e formation of carbon occurs very rapidly. This optimum seems t o be a t the point a t which the sum of t h e yields of diphenyl and carbon is a minimum. 3-Conditions favoring the formation of t a r probably affect the synthesis of anthracene similarly. FERMENTATION PROCESS F O R T H E PRODUCTION OF ACETIC AND LACTIC ACIDS FROM CORNCOBS' By E. B. Fred and W. H. Peterson AGRICULTER A L EACTFRIOLOGY AND ACRICULTURAL CHFMUNIVERSITYOF WISCONSIN, MADISON, WISCONSIN Received October 4, 1920
DEPARTMhNTS OF ISTRY,
800
825
850
875
900
925
950
975
Temperature "C. FIG.6-ANTHRACEXE
IN TAR
At 926" C. the amount of diphenyl which distilled over was much less t h a n t h a t obtained in the preceding run, and t h e formation of carbon was similarly smaller t h a n t h a t obtained in the following run. This would seem t o indicate t h a t a t the optimum temperature the sum of t h e yields of diphenyl and carbon is a minimum. I t is interesting t o note t h a t the increase in yield of anthracene was not only due t o t h e increased t a r yield, but also t o the fact t h a t the actual per cent of anthracene in the t a r increased with rise in temperature u p t o 925" C. (Fig. 6). Moreover, i t was noticed t h a t the reaction products varied from a light, red liquid 1
THISJOURNAL, 9 (1917), 350.
The commercial utilization of corncobs as a source of organic acids is a possibility which deserves careful investigation. When partially hydrolyzed and inoculated with certain bacteria, Lactobacillus p e n f o aceticzts n. s p . , the extract of corncobs ferments readily and yields almost equal quantities of acetic and lactic acids. If t h e yields on a commercial scale should prove equal t o what has been obtained in the laboratory, i t is estimated t h a t every t o n of corncobs would be capable of yielding more t h a n 300 lbs. of acetic acid and about 320 lbs. of lactic acid. The development of this process on a commercial scale would involve numerous chemical and technological problems, but the possibility of producing chemicals in this way was successfully accomplished during t h e war; more t h a n 5,000,000 lbs. of acetone were obtained by a fermentation process.2 The organism, Lactobacillus p e n t o a c e t i c u s 1%. sp., has certain characteristics t h a t make i t especially suitable for a commercial process. I t grows rapidly, produces large amounts of acid, and is able t o compete successfully with other organisms.3 Some idea of the possible value of corncobs may be gathered from the fact t h a t there are produced in the 'C'nited States alone more t h a n 20,000,000 tons of corncobs annually. A small amount of this material is used in the various stock feeds, but in general the cobs are discarded or used for fuel. I n 1918 LaForge and Hudson4 pointed out t h a t adhesive gum, acetic acid, crystalline xylose, and crystalline glucose could be obtained on hydrolysis of corncobs with sulfuric acid under suitable conditions, the yields of these different products constituting 1 Published with t h e permission of t h e Director of t h e Wisconsin Agricultural Experiment Station. 2 J . B i d . Chem., 4 1 (1920), 320. 3 Unpublished data. THISJOURNAL, 10 (1918), 925
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
212
approximately the following percentages of the weight
of the dry cobs: PRODl7CT Adhesive g u m . . Crystalline xylose. Acetic acid., Crystalline glucose.
............................. ......................... ..............................
........................
PER
CENT
30 5 2 . 5 to 3 37
I n a later paper LaForgel discussed in detail the production and use of this adhesive and other products obtained from corncobs. Hudson and Harding2 reported a yield of from 10 t o 12 per cent of crystalline xylose from corncobs, instead of 5 per cent. This higher yield obtained by Hudson and Harding represents, however, less t h a n half of t h e total xylose content of the cobs. Stone3 obtained 22 per cent of furfural, equivalent t o 38 per cent of xylose from the cobs which he used in the preparation of xylan and xylose. The corncobs used in the experiments reported in this paper gave on analysis 39 per cent of hrfural-yielding substances, calculated as xylose. I n their paper LaForge and Hudson pointed out the difficulty of finding a direct use for xylose. I n a recent paper we have shown4 t h a t xylose can be readily fermented b y certain bacteria with the production of acetic and lactic acids. This fermentation proceeds rapidly (10 t o 12 days), and results in about 90 per cent of t h e xylose appearing as the above end products. The fermentation closely approximates the following theoretical equation: Xylose CsHloOs 150
=
Acetic Acid CzHaOZ 60
Lactic Acid $CaH60a 90
9
where the acetic acid comprises about 40 per cent of the products and the lactic acid 60 per cent of the products. I n our work we obtained a ratio of about 43 per cent acetic acid t o 57 per cent lactic acid. If the fermentation of xylose is t o be of value from a commercial standpoint, i t would be much more profitable t o ferment the xylose sirup directly rather than the purified xylose. Moreover, the corncob sirup contains a much larger amount of xylose t h a n can be obtained in the crystalline form. It was found experimentally t h a t t h e pentose-fermenting bacteria would ferment the crude xylose sirup, yielding the same products, acetic and lactic acids, as were obtained by the fermentation of pure xylose. FERMENTATION O F CORKCOB EXTRACTS
Several fermentation experiments were made with the untreated corncobs and with hydrolyzed corncobs. It was found t h a t the unhydrolyzed corncobs can be fermented directly, but the yield of acetic and lactic acids i s small-about 1 g. of each acid from 100 g. of cobs-in comparison with the amount secured by fermenting the acid extract of the corncobs. The hydrolysis of corncobs can be brought about very readily, and results in a large amount of fermentable sugar. The degree of acidity, the time required, and the quantity of sugar produced are given in Table I. I n every case the cobs were hydrolyzed in an autoclave a t 15 lbs. steam pressure or about Chem. Age, 28 (1920), 332. J . A m Chem. SOC.,39 (1917), 1038. s Ber., 23 (1890), 3796 4 J . Biol. Chem., 39 (1919), 347.
I
2
Vol. 13, No. 3
TABLE I-REDUCING SUGARS OBTAINED FROM HYDROLYSIS OR CORNCOBS Reducing Extracting Sugars Solution Time as Xylose MATERIALS Per cent Minutes Per cent 1 Untreated cobs.. Water 90 2.9 Untreated cobs.. 0 . 5 Sulfuric Acid 10 7.7 Residue from water-extracted cobs. 2 . 0 Sulfuric Acid 10 10.3 Untreated cobs.. 2 . 0 Sulfuric Acid 20 19.6
................ ................ ................ Untreated cobs, first extract. ..... 2 . 0 Sulfuric Acid Residue from first extract.. ...... 2 . 0 Sulfuric Acid Residue from second extract., .... 2 . 0 Sulfuric Acid
120 120
...
24.5 12.0 .2.4 38.9
................ 2 . 0 Sulfuric Acid ................2 . 0 Sulfuric Acid
120 240
28.5 31.4
Total for all 3 extractions..
.........
Untreated cobs.. Untreated cobs.. 1 Air-dry basis.
60
121' C. An examination of the figures of this table shows that, with 2.0 per cent sulfuric acid, from 25 t o 30 per cent of xylose can be obtained from cobs by heating for 1 t o 2 hrs. Sirups prepared from the concentrated solutions were diluted with yeast water until t h e concentration of xylose was about 3.0 per cent. These solutions were then inoculated with pure cultures of bacteria and allowed t o incubate for 2 wks. or more a t 30' C. At the end of this time the cultures were analyzed, with t h e results giveh in Table 11. I t is clear t h a t a very complete fermentation has TABLE11-FERMENTATIONOF THE PRODUCTS Sugar Expressed Culture as Xylose Number Grams 41-11 3.0 55-9 3.0 69-19 118-8 /
i:o"
Volatile Acid as Acetic Grams 1.0962 1.1484 1.1032 1.0944
OF HYDROLYZED CORNCORS Nonvolatile Sugar Ratio of Acid as Represented Acetic t o Lactic by Acids Lactic Grams Per cent Acids 1.4004 83 44:56 1.4040 85 45 :55 1.3248 81 45 :55 1.3158 80 45 :55
taken place, since more t h a n 82 per cent of t h e sugar is accounted for by t h e two products, acetic and lactic acids. The extent of this fermentation is practically equal t o t h a t obtained by us with crystalline xylose, and clearly demonstrates the practicability of fermenting the sirup directly. T h a t the volatile and nonvolatile acids found are, respectively, acetic and lactic is established by t h e data in Table 111, where the results .of the analysis of TABLE111-ANALYSIS OF BARIUMSALTSOF ACIDSFORMED IN PROCESS OF
FERMENTATION
Culture Number 41-11 55-9 41-11 55-9
Kind of Acid Volatile Volatile Nonvolatile Nonvolatile
Weight of Barium Salt Taken Gram 0,2890 0.2428 0.2968 0,2496
Weight of Barium Sulfate Found Calculated Gram Gram 0.2630 0.2640 0.2198 0.2229 0.2152 0.2196 0.1800 0.1847
the barium salts-of these acids are given. I n the case of the two cultures examined the agreement between the found and calculated values is very good. Since i t is evident t h a t these organisms will ferment t h e acid extract of corncobs with the production of acetic and lactic acids, attention was directed t o t h e maximum amount of acids obtained from 100 g. of corncobs. Three successive hydrolyses on the same material were carried out. The first hydrolysis, in which 0.5 per cent sulfuric acid was used for 10 min., gave 2.2 g. of sugar; the second with 2.0 per cent sulfuric acid for 1 hr. gave 18.5 g., and t h e third with the same concentration of acid and for the same length of time as in the second hydrolysis gave 10.2 g. There was thus obtained by the three hydrolyses a total of 30.9 g. of sugar calculated as xylose. Culture media were made up with yeast water so t h a t the concentration of sugar in the three cases was 1.76, 2.0, and 2.0 per cent, re-
Mar., 1921
T H E JOURNAL OF IiVDUSTRIAL A N D ENGINEERING CHEMISTRY RECOVERING NEWSPRINT11 By Charles Baskerville and Reston Stevenson
spectively. T h e results obtained on analyzing the fermented cultures are given in detail in Table IV. TABLB IV-FERMENTATIONO F SUCCESSIVE ACID EXTRACTS O F CORNCOBS (Products per 100 g . of Air-Dry Cobs) Total Volatile Volatile Total Non- Nonvolatile Acid as Acid from volatile Acid AcTd from Culture Extract Acetic Fermentation as Lactic Fermentation Number Number Grams Grams Grams Grams Control First 0 . 2 100 .... 0,3600 1 18-8 First 1.0020 0.7920 1.2150 0.8550 .... 1.5525 Control Second 1.9647 8.9002 6.9355 9.8235 8.2710 41-11 Second 9 . 0 0 21 7.0374 9,4738 7.9213 11 8-8 Second 9.1853 8.5841 7.2206 10.1366 1 18-8 Second AVERAGE.. . 9 . 0 2 9 2 7.0645 9.8113 8.2588 Control Third 1.0282 0,6426 .... 41-11 Third 4.6573 3.6291 5.4625 4.8195 118-8 Third 4.8838 3.8556 118-8 Third 4.8654 3.8373 5.2418 4:5992 AVERAGE. .4.8022 3 . 7 740 5.3520 4.7094 Total of Three 14.8334 13.8232 12.6315 16.3783 Extracts
.... ....
....
....
....
.....
The total acetic acid obtained is 14.8 g., of which 12.6 g. were produced b y the pentose fermenters. I n the case of t h e lactic acid the total amount is 16.4 g., of which 13.8 g. result from fermentation processes. Of the total sugar present, about 86 per cent is accounted for by these two products. Analysis of t h e fermented solutions shows only slight traces (0.1 t o 0.2 g.) of unfermented xylose, and strengthens the evidence for almost quantitative conversion of the sugar into these two products. Although this fermentation process has not yet been tested on a large scale, i t apparently offers a profitable means of utilizing corncobs. SUMMARY
Corncobs offer a promising raw material for the commercial production of acetic acid and lactic acid. These acids are obtained b y fermenting a sirup made from corncobs hydrolyzed with dilute sulfuric acid. This hydrolysis is easily brought about and yields from 30 t o 40 per cent of xylose. Crude xylose sirup is rapidly fermented b y certain rnicrobrganisms, for instance, Lactobacillus pentoaceticus 12. s p . , with the production of the above acids. The fermentation is almost quantitative, since 85 t o 90 per cent of the xylose can be accounted for b y the two acids. During the month of January 1921, thirty-two chemical concerns with an authorized capital of $50,000 or greater were organized, with a total investment of $22,295,000. Three concerns had an authorized capital of more than $1,000,000 : the Oselda Corporation, the American Chemical & Drug Co., and Breinig Brothers, as compared with two companies of such capitalization in December, two in November, and m e in October. The following table shows the authorized capital of new chemical, drug, and dye companies organized since 1915:
................................. ................................. ................................ ................................ ............................... .............................
1915 1916 1917. 1918. 1919.. 1920....
$ 65,565,000 99,314,000 146 160 000 73: 403 :OOO 112,173,000 487,148.900
The New York Central Lines have made a series of tests on corrosion of tie plates and the best method of reducing the amount of corrosion. The tests have been made over a period of six years on special steel, Bessemer steel, high carbon Bessemer steel, open-hearth steel, pure iron, and malleable iron, and it has been shown that the corrosion is least with a steel containing 10.25 per cent copper.
213
COLLEGEOR THE CITY O F N E W YQRK,N E W YORK,N. Y.
T h e patent literature a n d a recent book3 on waste paper recovery describe processes for de-inking paper without discriminating between newsprint stock and bookstock. T h e known processes which give satisfactory results for bookstock are not necessarily applicable t o old newspapers, primarily on account of t h e notable proportion of ground wood present in newsprint stock. This communication presents a process b y which t h e ink and binder and oil are removed from old newspapers with minimum injury t o t h e fiber, and the pulp is furnished ready for use again for newsprint. I n our experiments we used a laboratory pulper with electrically driven propeller, a wooden box with brass gauze bottom as washer, a brass disk-maker with brass gauze bottom, a book press, and air drying. This was according t o t h e practice familiar t o a paper mill laboratory. T h e following conclusions give t h e result of about seven hundred experiments. When printed papers, e . g., old newspapers, are mixed with water, and pulped and washed, t h e ink is partly removed. T h e greater p a r t of the ink remains, because : ( I ) The binder of the ink is not removed ( 2 ) The carbon of the ink is entrapped in the pulp (3) The carbon of the ink adheres t o the pulp A well-known method for bringing t h e binder into solution or emulsiqn, or a t least removing i t from t h e fiber, is t o treat t h e pulped paper with a water solution of a n alkali. Too little alkali does not entirely dissolve or emulsify t h e binder, nor does it liberate completely t h e pigment of t h e ink; on t h e other hand, too much alkali is harmful in t h a t i t yellows wood pulp, which is a prominent constituent in newspaper stock. Also, too excessive alkali tends t o mercerize t h e fiber, and too much alkali makes t h e carbon remain in t h e pulp in such a condition t h a t i t does not wash out. We have determined t h a t 60 lbs. of caustic soda per t o n of old newspapers is t h e optimum concentration of alkali. We have found t h a t 2 0 0 lbs. of soda ash per t o n of old newspapers gives as good, if not better, results, especially in regard t o t h e yellowing of t h e paper. T h e soda ash is much more easily handled. T h e use of alkali alone is not sufficient t o liberate t h e ink so t h a t i t can be washed away. We have worked out a method which completely frees t h e pulp from t h e ink, binder, oil, and pigment. It consists essentially in t h e addition t o t h e alkaline solution of American fuller’s earth, which remains in suspension or in colloidal solution. We have found t h a t approximately I O O lbs. of this earth t o a ton e
1 Presented before the Division o€ Industrial and Engineering Chemistry a t the 60th Meeting of the American Chemical Society, Chicago, Ill., September 6 to 10, 1920. * Patent applied for. 8 Strachan, “The Recovery and Re-manufacture of Waste Paper,” The Albany Press, Aberdeen, 1918,
