Sugar Industry in Foreign Lands C. A. Bnowm, Bureau of Cheniibtry and Soils, Department of Agriculture, Washington, D. C.
A I Laceourd is given of observations upon the agriculture, chemistry, technology, and economics of sugar production in various countries which were visited by the author in 1929 and 1930. C0ndition.s in England, Germany, France, Spain, Czechoslooakia, and Egypt are described. GltISG an a-ricultural-chemical tour of sixteen inoritlis which the writer made in 1929 and 1930 through various countries of Europe and the Near East, considerable attention was devoted t o obvervations upon the chemistry, agriculture, technology, economics, and history of sugar production. I n the present paper only a brief r6sum6 can be given of some of these observations, as a complete review of all the information that was gathered would greatly exceed the limits of the present paper. In all the countries that were visited there w&s a, general state of agricultural and industrial depression, similar to that existing in the United States. There was tlie =me talk of the overproduction of sugar and other agricultural commodities; there was the same exisience, in varying degrees, of unemployment; and there was the same agitation about tariffs, taxes, subsidies, and other measures of relief. Time is lacking to discuss these economic remedies, many of which when put into effect had results that were not anticipated by their proponents at the beKinning. I n Egypt, for example, at the time of my visit the announcement of an increase in t,lie tariff upon sugar had the result of stimulating immediate importations of thousands of tons of this comrnodity before the proposed new law went into effect. The warehouses of Alexandria were glutted with sugar, far exceeding the immediate needs of consumption, from the sale of iv1rir.h afterwad the government derived not a particle of
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World War. The old establitiiied policy of free trade, under which Great Britain exchanged tho products of its mines and factories for its supplies of foodstuffs and raw materials, is now giving way to a policy of protection and of encouraging hitlierto neglected industries. Tlris new departure, like similar nationalistic movements in other countries, has for its purpose the strengthening of domestic manufactures and the rendering of the nation less dependent upon the outside world in the event of fut.ure commercial or political disturhances. Beet sugar manufacture in England was encouraged in the heginning by the granting of governmental subsidies, which were to be gradually diminished as the industry approached a self-sustaining basis. This latter condition, because of the general world-wide depression in the sugar markets, has not been realked; if the new beet sugar industry of England is to withstand the competition of cheap tropical fiugar, i t can do so only upon a continuance of the subsidy or by means of tariff protection. Certain techriologicai difficulties have also had to be surmounted in England. The most important of these has been the devising of means to prevent the pollution of streams and the killing of fish by effluent waters. The rivers of England are small and hence incapable of receiving so large a volume of contaminating wastes as the large streams of the United States and Europe. This difficulty has been over-
the increased revenue and Cor the purchase of which the consuiuer had to pay the subsequent increase in price. The sugar speculators profited greatly by these developments, but the sugar manufacturers of Egypt, whom tbe new Ian, was supposed to protect, suffered a temporary loss from the invasion of their markets with a Bood of cheap foreign sugar. BEET SUGAR INDUSTRY
come by reducing the quantity of waste waters from the sugar factories by an improved process of diffusion and also by devices for Btering and purifying the effluents before their discharge into the rivers. At the commencement of their operations the new beet sugar factories of England were obliged to employ foreign technulogists and chemists from the United States, Rolland, and Gennany. At several of the factories I had the pleasure of meeting fellow Americans. The training of a large body of competent Britivh technologists was one of the first problems of the new beet sugar industry in Endload. This is highly desirable, as foreigners are not always sympathetic with
ENGLAND The heet sugar industry of England is oiie uf those interesting nev- developments which have taken place since the
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British traditions. Foreign superinteiiileiiti are also prone to appoint relatives and friends to imiiortant posit.ions and thus there is the same danger, which our American beet sugar industry encountered several generations ago, of receiving a foreign and not a domestic t,ype of development. I visited four of the eighteen beet sugas factories of EnglandSelbv. Colwick. Burv St. Edmonds, and Ely. Id addition tb tli& four factories, I also v i s i t e d t h e expcrim e n t a l beet s u g a r factory a t Eynsham, near Oxford, w h e r e technological res e a r c h e s have been conducted for a number of years upon the d e s i c c a t i o n of sugar beet cossettes and the manufacture of sugar therefrom by the Oxford or modilied De Vecchis process ( 5 ) . The chief advantage elaimed for this system is that . . it e n a b l e s the faotory to operate with dried cossettes during the whole year and not for only a few m o n t h as is required by the usual method of diffusing the freshly sliced beets. It %'as generally held by the sugar technologists whom I visited in the various countries of Europe that tlie losses from increased fuel consumption and other causes by the new process more tlieri outweighed the advantages of continuous operation. The experiments attracted visitors from all parts of the world, but have now been discontinued. The following are a few of the objections that were ndvanced by foreign technologists against the Oxford process:
rrroee';s doe8 not therefore solvo the rriobleui of idle eo;i"&ent. . The prueess is much MOW expensbe than the preskni method (& 4 inure or ton of sugar according to one sthtement). Thk IS due mrtyv to the increased cost of evaooration ft,hr wntrr in hehydrating the cossettes haviig to beaddid &;in at the time of diffusion) and also to the inability to utilize waste
removes
The dried cossettes are bulky and will requirc
of extra storage space.
large amount
Beets are made into sugar which can be marketed immediately by the present method; there is the possibility of tying up capital by the Oxford prooess in stored cossettes which may undergo deterioration. T h e f:iimer olltaius his bect pulp for stock feed by the present rncthud at a time when Ire most needs it; by the Oxford process tho pulp m i ~ ynot he nvailnhie until snnirner when crass and other forage w e plentiful Flauketlup against the growing cane. The total amount of sugar cane ground per year a t Kom- Formerly tiie cane a t Kom-Ontbo was all unloaded by hand Ombo is a t present about 300,000 tons. The chief variety and several lruiidred men were employed to do the work now cultivated, making up 80 per cent of their planting, is a performed by about twelve workers. The cane on entering tlie factory is passed first t,lirouglt tlie Java seedling, known as No. 105, of the slender, light colored Uba type. It gives a yield per acre of 40 to 50 tons and has a rolls of a corrugat.ed crusher and then through five threesucrose content of 12.5 to 13.5 per cent a t the time of harvest. roller mills (Cail manufacture). Six minutes are required The remaining varieties consist of a purple cane, called the for tho cane to pass through tiie entire system of rollers. Baladi, giving a yield of only 20 to 25 tons per acre but with a Maceration is employed and an extraction of 95 per cent was sucrose content of 13 to 14 per cent; the Rubanee, or ordinary reported a t the time of my visit. The bagasse is conveyed by striped or ribbon cane, of the same yield and sugar content carrier to the boilers where it is fed to the fire boxes, partly as the Baladi; and a new Java seedling, No. 2714, with a by Iiand and partly by mechanical stokers. The cheap labor sucrose content of 13 to 14 per cent, but giving a smaller of Egypt (a good worker can be hired at 20 to 25 cents per yield per acre than the KO. 105. It was stated by the day) has delayed the introduction of many labor-saving agronomic engineer at Kom-Ombo, S. Mezrahi, that no cane devices that have been found necessary in other countries. had yet been found which equals the Xo. 105 in production of Bagasse supplies about 90 per cent of the fuel necessary to run the factory a t Kom-Ombo; oil and coal (from England) sugar per acre under the conditions of this estate. supply the remaining 10 per Cane is planted at Komcent in about equal quantiOrnbo in February and Marcli ties. The expenditure for and is cut after growth of one foreign fuel will shortly be year. It is allomd to ratoon entirely eliminated by burnfor two years. I was suring the excess molasses which prised to learn that the first is left after s u p p l y i n g the year's stubble frequently exneeds of the alcohol distillerceeds the plant cane in tonies. The nature of the pronage; this was attributed by posed installation for bnrnMezrahi to the greater deing molasses at Kom-Ombo velopment of new s u c c o r s is not known t o the writer at from tlteroot buds. The cane present. Molasses burning doesnot arrow a t Kom-Ombo; for steam production, with the failure to do so is attribsubsequent recovery of potash uted to the extreme dryness from the ash, has been a suhof the climate. ject of frequent diccussion in During the grinding season, tlie literature. In one type sample carloads of cane from of proces.s t h e m o l a s s e s is the field are taken each day thoroughly incorporated with to slreds where tlie stalks are the bagasse before burning weighed and then cleaned of under the boilers. Vhen the adhering trash, the latter bemolasses is hurried alone it ing weighed and the perceutmust be subjected to a preage determined. At the time liminary process of charring of my visit the percentage of to prevent frothing.. Special trash for the Java No. 105 p r e c a u t i o n s must also be cane was 2.415, and for tlie taken to prevent slag formaBaladi p u r p l e c a n e 1.836. tion from fusion of the asli These percentages, as deter(1-4,6,9,11,18). rninod each day for the sample The juice from the crusher loads, rr'ere applied to the and millsis first sulfured, then total amount g r o u n d at the limed to neutrality, heated, factory, whieli wasabout 2500 s e t t l e d , a n d filtered, first tons per day. Experiment.s through bagasse and finally were b e i n g tried a t Komthrough Dehne filter presses. Omho upon u t i l i z i n g the The clarified filtered juice is upper green part of the cane then evaporated in quadruple for seed, tlielessvaluablepart effects and boiled to grain in of the stalk thus being used FXQURE 4. OX-DEWENSakia FOR HOXSTINO WATERFOR Cail v a c n u m p a n s . The for planting, and tlie richer h U G A T l O N , ABn SIMBEL, EGYPT
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Vol. 25. 5".1
January, 1933
I N D US TR IA L A N D E N G I N E ER IN G C H E M I STRY
strikes of raw sugar are purged in Watson-Laidlaw centrifugals, sixty in number, each one of which is electrically operated by an independent motor. A high-grade white sugar of about 99.5 polarization is now the only kind manufactured a t Kom-Ombo. The sugar is packed in 100-kg. bags and stored in warehouses for shipment to the refinery a t Hawamdia. The molasses is stored in tanks and also in open reservoirs of banked earth, previous to being shipped to the distillery. There were five cane sugar factories operating in Egypt a t the time of my visit, these in order of production being Nag Hamadi, Armant, Kom-Ombo, Sheikh Fadl, and Abu Kirkas. All of them belong to the Soci6t6 Gen6rale des Sucreries et de la Raffinerie d’Egypte. SUGAR REFINING IN EGYPT. The raw sugar manufactured a t the five factories previously named is sent down the Nile to the refinery of the Soci6t6 Gen6rale a t Hawamdia. Through the courtesy of H. Naus Bey, general administrative director of the Soci6t6 Gen6rale des Sucreries et de la R a f i e r i e d’Egypte, I was granted the privilege of visiting this refinery which, for the variety of its operations, is one of the most interesting establishments of its kind in the world. It is picturesquely situated among groves of palm trees upon the bank of the Nile. The Hawamdia refinery a t the time of my visit (February, 1930) employed some two thousand men and was melting about 420 tons of raw sugar a day, although on occasions this figure was raised as high as 520 tons. The raw sugar received from the factories up the Kile was of very high quality (all above 99” and a large amount polarizing as high as 99.4” to 99.5”). Some of the factory sugars were, in fact, pure and white enough to go into direct consumption but most of them were remelted and refined. The Soci6t6 Gen6rale des Sucreries finds it advantageous to produce this high grade of raw sugar, as the operations of its own refinery are thereby greatly facilitated. The methods of refining a t Hawamdia are most varied, and the visitor has the opportunity of seeing, side by side with the most modern processes, methods which have been discontinued in some other countries for half a century or more. A brief account of operations, as observed a t the time of my visit, is as follows: The raw sugar was emptied from the bags into small tanks upon trucks where i t was treated with concentrated sugar sirups of increasing purity. After the sugar had stood in contact with the sirup of lowest purity for a period sufficient to dissolve the film of adhering molasses, the liquor was removed from the tank by suction and a sirup of higher purity applied. After a series of these affinations, when as much as possible of the adhering molasses was removed, the purified sugar was melted to a concentrated sirup and the suspended impurities precipitated by adding a requisite amount of albumen dissolved in warm water. The impurities, carried down by the coagulation of the albumen in the hot sugar solution, were then removed in a flter press and the filtered sirup passed through bone char filters of which I observed about eighty. The bone char was obtained mostly from France and Holland, the specimens observed being of much coarser grain than that usually employed in our American refineries. The clarified sirup from the char filters was evaporated and boiled to grain in vacuum pans in the usual way. A certain amount of the massecuite was then run either into open coolers, where it was stirred a number of hours by rotating paddles, or else into closed rotating crystallizers whose temperatures could be regulated by water circulating through longitudinal pipes. From the coolers or crystallizers the massecuite was purged in centrifugals, which were of the Watson-Laidlaw type, each one being separately driven by
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its own electric motor. The sugar from the centrifugals was then pressed mechanically into slabs which, after drying in ovens, were cut into dominoes. Another method of treating the massecuite was to run it into metal cones which. after standing for the completion of the growth of crystals, were packed into cylindrical metal baskets (ninety-six cones to the basket) and then whirled in centrifugals to remove adhering mother liquor. The cones of sugar after removal from the centrifugals were then dried in ovens and the resultant white loaves, weighing about 1800 grams each, wrapped by hand in paper sheets and then shipped out in boxes or bags. The output of the refinery a t the time of my visit was 100,000 loaves per 10-hour day a t thirteen wrapping tables, although this amount was raised a t times to 125,000 loaves or more per day. The demand for hard loaf sugar persists among the native population of Egypt and the Soudan, as it was the first kind of refined sugar with which they became familiar and they believe such sugar to have superior quality and sweetness. Owing to the limited capacity of the loaf sugar centrifugals a t the time of my visit, some loaf sugar was also being made by the old “fill house” method. The cones, after being filled with massecuite, were placed in holders on cars which were wheeled into hot rooms where they remained a day or two for the crystals to complete their growth and then to be washed with a highly concentrated high purity sirup. This was the oldest part of the refinery installation a t Hawamdia, dating back over 40 years, and it was the only survival of the ancient “fill house’, in actual operation which the author has ever seen. When crystallization and washing were completed in the hot room, the cones of massecuite were placed with the open points down in cups attached to a large system of suction pipes, and the adhering mother liquor was drawn off. After thorough draining by suction, the cones were then emptied and the loaves of sugar dried in ovens. I n addition to dominoes and loaf sugar, Hawamdia also manufactures white slabs for the use of confectioners. The massecuites are purged in Adant turbines and the resulting slabs are dried in ovens. A considerable amount of granulated sugar is also made for the use of hotels and the domestic trade. At the time of my visit the output of granulated sugar was about 120 tons per day. There is no demand in Egypt for soft refined sugars or for table sirups, and these products are not manufactured a t Hawamdia. The massecuites of highest purity are worked up into the prime quality loaf sugar which brings the highest price in Egypt, 10 pounds of such sugar a t the time of my visit retailing a t 10.5 piasters or 52.5 cents. The molasses from this sugar is boiled to a large grain, and the sugar thus formed, after being well washed in the centrifugals, is dried to form granulated sugar which a t the time of my visit retailed according to grade a t 8.5 to 10 piasters for 10 pounds. The rnolasses from the second strike is again boiled, with the production of lower-grade sugars which, after being affined and remelted with the raw sugars, are worked up into loaf and granulated. The final refinery molasses of about 52 per cent purity is sold to distillers for making alcohol. The chemical control a t Hawamdia is along the usual lines followed in all refineries. There are, however, several interesting modifications that were explained to me by the refinery chemist, A. M. J. Honor6, whose father for many years was a merchant in New York City. One of these modifications is the employment of the normal weight of 20 grams which is used not only a t Hawamdia but a t several of the sugar factories in Egypt. The saccharimeters are of SchmidtHaensch construction and equipped with a special scale adapted to the 20-gram weight of sugar. Honor6 stated that the labor of calculation is so reduced by use of the 20-
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INDUSTRIAL AND ENGINEERING CHEMISTRY
gram normal weight that a chemist after using it but once is convinced of the reasonableness and advantage of this improvement. The consumption of sugar in Egypt, which was 160,000 metric tons per year at the time of my visit in 1930, has since decreased to 135,000 tons; the production, which was only about 100,000 tons three years ago has now, as a result of favorable government legislation, been increased to 150,000 tons per year, which slightly exceeds the present consumption. This increase in production was easily accomplished by the different plantations making the necessary extension in the areas of land for growing sugar cane. Inasmuch as the sugar industry of Egypt has now succeeded in bringing its production up to the demands of local consumption, which was the main object of the protective policy recently inaugurated by the Egyptian Government, a further expansion of the cane sugar industry of Egypt is not likely to occur under present economic conditions. I n concluding these sketchy personal observations upon the sugar industry in different countries I wish to mention the great cordiality which was extended to me in every country where I made my visitations. It would be impossible to mention the names of all of those to whom I owe obligations. I can only say that as I pursued my journey, which
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was without a single unpleasant incident, I came to feel more and more that the sugar chemists and sugar technologists of the world constitute a great brotherhood whose chief tenet is the simple requirement of comradeship, helpfulness, and good will. LITERATURE CITED Anonymous, Arch. Suikerind., 32, 459-60 (1924). Ibid., 35, 538-42 (1927). Ganswijk, C. C. W.van, Zbid., 32, 1065-8 (1924). Harreveld, P. van, Ibid., 32, 1095-6 (1924). Inst. for Research in Agr. Eng., Bull. 4, Clarendon Press, Oxford, England, 1929. Kaufman, H . J., Arch. Suikerind., 32, 359-67 (1924). Kriiger, Ts’., “Das Zuckerrohr und seine Kultur.” Magdeburg, 1899. Kriiger, W., and collaborators, “Ernahrungsverhaltnisse, Anbau, Diingung und Krankheiten der Zuckerriibe,” Bernburg, 1927. Rodziewicz, A , , Gaz. Cukrownicra, 68, 133-5; L h t y Cukrovar. 49, No. 26, Rozhledy 24 (1931). Saillard, E., L a . Planter, 78, 469-71 (1927). Schott, G. J., and Harreveld, P. van, Arch. SuLkeririd., 32; Mededeel. Proefstation Java-Suikerind., No. 14, 449-63 (1924). Seite, G. E. G. yon, -4rch. Suikerind., 28, 519-33 (1920). RECEIVEDBpril 6, 1932. Presented before the Division of Sugar Chemistry a t the 83rd Meeting of the American Chemical Society, New Orleans, La., &arch 28 t o April 1, 1932.
Gel Formation in Sodium Metasilicate Solutions M. J. PRUCHA AND C. A. GETZ, College of Agriculture, University of Illinois, Urbana, Ill.
S
ODIUM HYDROXIDE, trisodium phosphate, sodium combinations of them were studied as to their influence on carbonate, and sodium bicarbonate, used singly or mixed gel formation in sodium metasilicate solutions: in varying proportions, have been the principal ingrediAddition of lactic acid ents of the alkaline detergents used in dairy plants for cleaning Addition of other alkaline washing powders Addition of sour milk and sweet skim milk purposes. Recently another compound has been added to formation in other alkaline washing solutions in presence this list of detergents-namely, sodium metasilicate. This of Gel milk compound is especially recommended for the washing of Addition of other alkaline washing powder, sour milk, and milk bottles in the soaker-type bottle washer. milk solids Effect of agitation According to Vail (I), sodium metasilicate is an excellent Effect of temperature detergent, and in some respects is superior to the other detergents commonly used. However, an objection has been The experiments were carried out in the laboratory as raised against its use in the soaker-type bottle washer on the follows: Pyrex glass flasks were used for the solutions. To ground that the washing solutions may form a gel. varying concentrations of sodium metasilicate solutions were The knowledge as regards gel formation in silicate solutions added different amounts of lactic acid, sour milk, milk powder, is fully summarized by Vail ( 2 ) . Nevertheless, it seemed and the different washing powders. Each addition of the desirable to undertake a study to determine what factors above substances was followed by a vigorous shaking. The may cause gel formation in sodium metasilicate washing solutions were allowed to stand for a certain number of hours solutions when used in dairy operations. and then observations as to gel formation were recorded. The practice as regards the use and care of the washing The sodium metasilicate used had the composition NazSiOp solutions in the bottle washers varies in different milk plants. 5Hz0. I n some cases a fresh solution is prepared daily, whereas in The results of the experiments are summarized in Tables I other plants the same solution is used day after day for a to X. The following characters were used in the tables to month or longer. The strength of the washing solution is designate the condition of the solutions studied as regards maintained by occasional additions of the detergent. Under gel formation: such practices there will gradually accumulate in the washing - denotes no gel formation solution a considerable amount of milk solids and of acid * denotes a tendency to gel + denotes a weak gel (mostly lactic) from the milk that adheres to the walls of denotes a strong gel the bottles. Another common Dractice in some Dlants is to mepare EFFECTO F LACTICACID ON GEL FORMATION I N aODIUM washing solutions b y mixing two or more of the different METASILICATE SOLUTIONS washing powders in varying proportions for the purpose of I n this experiment, the results of which are given in Table I, improving the cleansing properties of the solutions. I n view of these varied practices, the following factors and Lvarying amounts of lactic acid were mixed with sodium meta-
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