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nothing to meet the great emergency? By no means! Economic campaigns more alluring and important than any planned by military leaders are called for, and the rewards t o be reaped are almost beyond conception. Already special alloys have been prepared for use as substitutes for platinum. The “fixation of nitrogen,” or its conversion from inert, free nitrogen of the atmosphere into valuable products like ammonia, nitrates, and cyanides, is a commercial success. But the greatest of the three desiderata remains an unsolved problem, viz., how can immense stores of potash locked up in our feldspars, leucites and many rocks, be freed from their “entangling alliances,” and made available to our manufacturers and-most important of allto our farmers? The problem is not necessarily incapable of solution, but prolonged, persistent, painstaking effort, with ample provision for large scale experimenting, are needed. The Napoleonic Wars gave us cheap soda; will the World War of a later century give us cheap potash? 809 KEARNSBUILDING SALT LAKE CITY. UTAH
THE RECOVERY OF POTASH FROM BEET-SUGAR HOUSE WASTE LIQUORS’ By H. E. ZITKOWSKI The recovery of the residual values from beet-sugar waste liquor has been the subject of serious investigation even prior t o the war. However, the abnormally high potash prices of the past few years have brought about renewed efforts in this direction. FUNDAMENTAL CONSIDERATIONS During the 1916 season approximately 6,000,000 tons of sugar beets were produced in the United States. In all probability a materially greater tonnage will be produced this year, and the possibilities for increased production in the immediate future are promising, though this phase of the problem is so intimately related to the tariff, the agricultural labor supply, and ruling prices of other agricultural products, that prophecy is fruitless. The composition of the beet, and therefore its content of potash, is variable from season t o season and in different localities and soil conditions. The following analyses of beets from three widely separated localities in the United States can serve as a basis. Colorado California(o) Wisconsin(a) Moisture.. 78.36 per cent 63.99 per cent 74.37 per cent Dry substance.. ........ 21.64 36.01 25.63 Ash (carbonate). ........ 0.89 0.88 ..... Total nitrogen., . . . . . . . . 0.199 0.254 0.1817 25.60 18.7 Sugar.. ................ 15.40 MINERALMATTER(PER CENT ON BEETS) 0.065 0.040 0.102 c1 0.034 0.024 so3 .................. 0.028 0.121 0.023 PaOs.. ............... 0.046 0.269 0.320 Kz0 ................. 0 . 3 2 0 0.106 0.089 NazO.. . . . . . . . . . . . . . . 0.097 0.078 0.041 0.032 CaO.. 0.051 0.047 0.058 MgO 0.014 0.027 0.042 Fez0a.AlzOa.. 0.016 0.036 0.005 SiOn.. ( a ) Both the California and Wisconsin samples were several days in transit to the laboratory at which the analyses were made, and undoubtedly lost considerable moisture by evaporation which consequently increased the percentage content of dry matter. Aside from that the California sample was abnormally high in sugar content.
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From an agricultural and economic view-point-aside from the sugar-the nitrogen, phosphoric acid and potash content of the sugar beet is of more than passing importance. Accepting the average of the three analyses herein reported as the average for the entire production, the 6,000,000 ton crop of beets of 1916 contained: NITROGEN 12,700 tons
PHOSPHORIC ANWYDRIDE 3,780 tons
POTASSIUM OXIDE 18,180 tons
Investigations indicate that in extracting the sugar values by the diffusion process approximately 60 per cent of the nitrogen 1 Presented at the Buffalo Meeting of the American Institute of Chemical Engineers, June 20 to 22, 1917.
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and 90 per cent of the phosphoric acid and potash content are extracted with the sugar and pass into the process, the rest remaining with the pulp. As this pulp is now completely utilized for live stock feeding purposes, the plant food values of this pulp are not lost t o agriculture except in so far as farmyard manures are inefficiently utilized. Of the plant food values extracted and now in the juices phosphoric acid is completely eliminated as calcium phosphate, and t o date largely wasted. A part of the nitrogen content is eliminated as coagulated protein and otherwise, together with the phosphoric salts. The potash, however, is not eliminated from the juices by the usual processes of purification and is found in the final molasses, i. e., the mother liquors, from which sugar cannot be further recovered by direct crystallization, and for this condition potash salts are partly responsible. The production of molasses from beets is somewhat variable from season t o season, but an average percentage production for the United States will be somewhere between 5.5 to 6.0 per cent on beets. With a six millon ton crop of beets this totals 330,000 to 360,000 tons. A study of a series of thirteen samples of American beet molasses as reported in Sugar, Vol. 18, No. 4, indicates an average content of 1.69 per cent nitrogen and 4.66 per cent potassium oxide (KzO). On this basis the beet sugar molasses production of the past campaign contained between 15,4w and 16,700 tons of K20, which checks fairly closely with the figures above estimated. Of the total beet molasses production perhaps 5.0 per cent under normal conditions, but under present conditions double this amount or more, is used in alcohol production and the still residues, containing the potash, are concentrated and usually enter the fertilizer trade and are, therefore, not lost to the general economy, Approximately 40.0 per cent of the total molasses production is used for stock feeding purposes, in part direct as such, but by far the greater part is mixed with some absorbent feed, frequently beet pulp, either fresh or dried, and also many of the fodders. The potash values in this case are recovered in proportion as the manurial values from these feeding operations are recovered. The remainder of the United States molasses production, perhaps 45.0 per cent of the total (during the past season from 148,000 t o 152,000 tons) is desugarized, that is, sugar is extracted in marketable form. It is this portion of the beet crop that contains the possibilities of potash production in commercial form a t the sugar factories. STEFFENS PRECIPITATION PROCESS
The process now used almost exclusively in this country in extracting sugar from this molasses is known, after its inventor, as the Steffens precipitation process, in which sugar is precipitated as tri-calcium saccharate. PROCEDURE-Molasses of about 80.0 per cent solids is diluted t o I O to IZ per cent solid content, cooled t o about 15.o’C. and under suitable means for cooling and stirring, finely powdered calcium oxide is dusted into the solution. If the conditions essential t o the process are adhered to, 90.0 per cent or more of the sugar is precipitated as a calcium compound and is removed from the mixture by filtration. The filtrate, now with a content of solid matter of 5 t o 7.0 per cent contains practically all of the potash originally in the molasses and also variable percentages of sugar not precipitated above. The sugar in solution is probably present in the form of di-calcium saccharate, C12H2z011.zCa0. If this cold filtrate is heated t o 85‘ C. approximately 60.0 per cent of the sugar in solution is precipitated as a calcium saccharate probably according to the following reaction : 3C12H22011.zCa0 ~ C ~ ~ H 2 ~ 0 ~ 1 .f 3 CC1 azO H22011
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The reaction is reversible and on cooling the saccharate formed dissolves: hence it is necessary to filter a t the precipitation temperature. This, known as the “Hot Saccharate” process, is now quite generally used t o recover from the solution additional sugar values which are not: readily and economically recovered by the first step or cold process. The filtrate, now known as Steffens hot waste water, still contains from a few hundredths t o 0.4 or 0.5 per cent of sugar, some lime, practically all of the potash and most of the other non-sugars present in the molasses. This is the waste liquor forming a potential potash supply. PRESEST USES OF WASTE LIQUORS
In several instances where the sugar company controls agricultural lands in quantity adjoining the factory, these waste liquors, together with other residues, are used to irrigate the lands. This is perhaps the most economical method of utilizing the residual values, as all of the potash and phosphoric acid and nearly all of the nitrogen of the beet can be returned to the soils, but this is practical only in isolated instances, and only about 8.0 per cent of the total beet crop is handled in this manner. In still other of the irrigated sections where the residual waters are discharged into existing streams and the streams are subsequently diverted for irrigation purposes some of the values may be inadvertently utilized, but in any event the losses t o the economy of the state must be very considerable by this method of disposal. I n most cases the waste residues are sent into settling basins, the clear effluent of which reaches the streams and is carried away. Efforts had been made even before the war to recover these values, and owing to the stimulus of high potash prices of recent years the work in this direction has been followed with more than usual vigor. However, the problem has its difficulties. Since the hot waste water as produced is very dilute, containing 96.0 per cent or more of water, it is necessary t o concentrate it. As produced it contains 0.2 t o 0.5 per cent of free lime, CaO, which will foul the evaporating surfaces if not removed. This is readily enough accomplished by carbonating (injecting COZ gas) and filtering1 The carbonated and filtered waste water varies in composition with the season, locality and factory practice, but the following is typical : PERCENTAGES: D r y Carbonate Organic Moisture Substance Ash Sugar Non-sugar 97.00 3.00 1.00 0.30 1.70
Nitrogen 0.16
Potash
Ki0 0.35
This indicates a t once that the content of values is low, the cost of evaporation comparatively great, and also that, under normal conditions, when the value of a unit of nitrogen is two or three times that of a unit of potash, the nitrogen values are as great or greater than those of the potash contained in these waters. Up to a content of 50 t o 55 per cent. dry substance this water can be readily enough concentrated in multiple effect evaporators, and quadruple as well as quintuple effect evaporators have been used very successfully. With a content of more than 5 5 per cent dry matter the liquor begins to salt out and foul the heating surfaces. However, beyond this point the material can be readily enough concentrated still further, and brought to a dry state by the use of one of the various types of vacuum drum dryers. The trouble is to keep the material dry. I I t might be stared t h a t during t h e past campaign in one case these waters u e r e concentrated b y t h e direct gases from a n oil fire passing upward through a sheet metal gradier over which t h e waste liquors doived. I n this case removal of t h e lime was not necessary as t h e heat transfer was hrought about by direct contact without a n intervening metallic surface. This method of evaporating is prohibitive as t o costs under normal conditions.
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The dried material containing I O to 12 per cent of KyO and 5.0 per cent nitrogen is so exceedingly deliquescent and absorbs atmospheric moisture so readily that it becomes fluid in a very short time. Various absorbents have been used to overcome this difficulty, one of the most successful being dried slaughter-house wastes, which incidentally are deficient in potash so that the two materials complement one another. Ultimately this may prove to be a direction in which considerable quantities of the sugarfactory wFaste waters will be utilized, but unfortunately only a few beet-sugar factories are now located within reasonable distance of the meat packing centers so that the cost of freight enters. I n some localities small quantities of 50 to 55 per cent dry substance have been disposed of in tank car lots directly to the agricultural industry as a liquid fertilizer. In other instances i t is urged t o sell the liquid fertilizer direct to the farmer for use by saturating barn manure with it. It is doubtful whether material quantities can be disposed of in this form a t present. With present potash prices the nitrogen values have lost their relative importance with the result that in a t least one instance these have been sacrificed in order t o obtain a product comparatively high in potash content, which would permit its shipment considerable distances to the potash consuming centers. When the Steffens water is concentrated t o about 55.0 per cent dry substance it can be quite readily ignited and charred, owing to its high content of sugar and other organic matter, its own content of combustible matter then furnishing most of the necessary heat. The char, or crude ash, thus produced contains from 30 t o 35 per cent potassium oxide, but only traces of nitrogen. This procedure is economically justifiable only with present potash prices. In other directions experiments are being made towards a recovery of the potash salts in comparatively pure form, a t the same time saving the nitrogen values. The above roughly covers the efforts made in the recovery of the values of the beet-sugar liquor residues. PROGRESS I N RECOVERIES
Technically, the recovery of the potash values from these liquors is a comparatively simple and perfectly feasible problem. It is simply one of evaporating the dilute liquors as economically as is practical, charring the residue t o produce the crude ash and leaching and recrystallizing if this is desired. The quantities of water t o be evaporated, however, are large, the necessary equipment costly, and such a procedure has commercial possibilities only during war prices. Now it is true that almost any sugar factory could have paid for a potash recovery plant in one year with present potash prices, but the war may end any time and leave a lot of very costly equipment on hand, especially as the cost of such equipment, evaporators, boilers, etc., is abnormally high a t present. Then also a beet-sugar factory operates seasonally only: the average length of the operating season is only about IOO days, and the earnings must be made during this short period. B u t a t that some progress is being made, and a t least one concentrating plant is under construction and several others under consideration and more of the values will be recovered during the 1917 campaign than during the past. However, in these instances a recovery of all the values in the liquors is aimed at, not the potash values only. This will be touched briefly below. Approximately the disposition of the potash in the sugarbeet crop grown in the United States a t present is as follows: Returned to Farms in Pulp Found in Molasses Produce
. . . . . . . . . . . 1 0 . 0 per cent . , . . . . . . . . . 9 0 . 0 per cent
The potash found in molasses is distributed as follows: To Alcohol P l a n t s . . . . . . . . . . . . . , . . . . . 10.0 per cent plus Used as Molasses F e e d s . . . . . . . . . . . . . . . 40.0 per cent plus Desugarized., . , . . . . . , . . . . . . . , . . . . . , . 4 5 . 0 per cent plus
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This leaves under control of the manufacturers only about 40.0 per cent of the potash content of the beet which on the basis of a six million-ton crop amounts t o between 6800 and 7500
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THE INFLUENCE OF PIGMENTS ON RUBBER' B y MAXIMILIAN TOCH
Rubber has a strange analogy to linseed oil and China wood tons of K20. oil, and although as far as we know the chemical compositions This quantity is now disposed of as follows: of rubber and the drying oils are totally different, this analogy holds good for reasons that we cannot explain. In 1904 I deDirectly to the soil as factory sewage.. . . . . . . , , , , . , . , , , . . . 2 0 . 0 per cent Concentrated t o 5 0 - 5 5 per cent dry substance and sold to livered a lecture on the chemistry of the rubber pigments before fertilizer factories. . . . , . , . . . , . , , , . . . . , , , . Concentrated and calcined to a crude ash. . , the American Chemical Society, and I published it privately, Discharged into streams (representing the ................................. 7 0 . 0 per cent for I knew a t that time that it should not be taken as final on account of my limited knowledge of the subject, but in thirteen Thus far the subject has been considered from the angle of years I have learned a little more on the subject so that I am recovering the potash for the chemical industries or the potash able to-night to give you some facts which should be helpful. and nitrogen as fertilizers only. That does not by any means The rubber industry thirteen years ago was insignificant, exhaust the possibilities. Beet-sugar molasses and therefore that is to say, if rubber and its compounds had been entirely the waste water contains a great number of substances which in destroyed from the face of the earth we would not have suffered themselves are valuable or may serve as the mother substance very seriously for any great length of time because matters would for valuable products. The possibilities can here be touched have adjusted themselves, with perhaps some inconvenience, on only very briefly. in less than a year. The loss of hard rubber would probably GERMAN TREATMENT OF WASTE LIQUORS not have been felt for any great length of time, owing to the Even in the case of potash and nitrogen it appears from the fact that celluloid and some of the lighter metallic alloys would experience of Europe that the general economy is served best by have replaced it, but to-day, we face a different situation. Take combining these into a more valuable product. From Ger- the automobile industry alone, which I am informed ranks many it is reported that by the Bueb process of destructive third in size and money invested in the United States, and the distillation the waste liquor of molasses desugarizing processes rubber industry sixth or seventh in size and investment in the United States, and you will plainly see that without rubber operating by the strontium process, in that country, produce tires the automobile industry could not exist with the same annually 5000 tons of potassium cyanide and 5000 tons of measure of success. ammonium sulfate. Steffens waters can be similarly utilized At the Eighth International Congress of Applied Chemistry and a United States patent has been granted for such a process. held in New York in September, 1912,Dr. Duisberg showed The molasses waste liquors contain a whole series of organic a piece of synthetic rubber, made in Germany, which weighed acids which can be recovered and are valuable to industry. perhaps 20 kilos or more, and two automobile tires, made from The nitrogen of these waste liquors occurs in various forms, this synthetic rubber, which had traveled 4000 miles, and appartly as a plant base of which the principle is betain, which parently this rubber was as good or better than the natural. has found some application in medicine. A large part of the But if our information is correct, synthetic rubber is only a nitrogen content exists in the form of amido acids. These it laboratory product, and the Central Powers are suffering trehas been shown by Effront can, by suitable fermentation promendously for the want of rubber in warfare, for without i t cesses, be split into ammonia and a mixture of volatile fatty no staff officer can travel any great distance and ambulance acids, acetic, propionic and butyric. Recent investigations work becomes a hardship and a menace with tires made of any in this country indicate that a mixture of the high boiling point other material, so that we must conclude that artificial or synketones valuable in cellulose technology can be prepared from thetic rubber is not yet a commercial success. The submarine this liquor. that has been making several trips between Germany and the Ehrlich insists that the amido compounds present in conUnited States took back a cargo of platinum and rubber, siderable quantities in beet molasses waste liquors are the mother indicating that rubber is an essential without which certain substances of fusel oil, more particularly amyl alcohol, and industries cannot hope to make much progress. suggests extracting these compounds and utilizing them t o We accept the composition of rubber as being a terpene increase the fusel oil prodhction. This indicates only a few of the possibilities. While it is not claimed that beet molasses may composed of C5Hs, but rubber as it is derived from the latex yet prove another coal tar, chemically it may be almost as of the fig tree is much more complex and contains an appreciable quantity of oxygen; yet when the resins are extracted and interesting. But little has been done in developing the waste liquors we have a clean, elastic mass of the Para type there is no question of the composition of this mass being CsHs, or perhaps C10H16. values in this country. The reasons are various. Not the least The difference between hard rubber and soft rubber is a queslies in the fact that sugar is a sort of national and international political football. Between duties, bounties, premiums, special tion of degree, vulcanization and percentage of sulfur. If we international agreements (as, for instance, the Brussels Con- were to draw a hexagon of hard rubber and soft rubber we would ference) and competition with the tropics, the beet sugar in- have to conclude that the sulfur combination of rubber has two dustry in the United States has never felt sufficiently safe t o eutectics. venture in new directions. Rubber comes to the manufacturer now in a fairly pure state. At the outbreak of the present war the outlook was particu- Raw rubber contains moisture and foreign substances to a very larly dark. The tariff had been lowered, and a duty-free sugar large extent, all of which must be removed before the rubber clause enacted t o go into effect May 1, 1916. Fortunately, this is vulcanized. When cleaned rubber is mixed with from 3 t o latter clause was repealed before going into effect. 5 per cent of sulfur and placed in a vulcanizer under pressure What the development of the future may be will depend for several hours a soft rubber is the result, that is t o say, i t more upon legislation following cessation of hostilities than has a greater elasticity than the raw material from which i t has present high prices and in this respect the beet-sugar industry been made and a distinct combination has taken place between is not differently situated than most other chemical industries the terpene and the sulfur. If, however, from 30 to 35 per cent In this country. of sulfur is added to the rubber and the pressure and heat conA ~ Y E R I C A NBEET
SUGAR COMPAHY
ROCKYFORD,COLORADO
I Address before the Syracuse Section of the American Chemical Society, Syracuse University, Syracuse, N. Y., April 13, 1917.
