T H E J O LTRNAL O F 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
Oct., 1916
heat. Eighty per cent of the castings were recovered and put into service and are in use a t the present time. Ninety per cent nitric acid made in a plant equipped with “Duriron” castings showed a n average iron content of 0.0014 per cent iron while 36 Be. nitric acid (52.30 per cent) showed 0.0042 per cent iron. The silicon iron alloy was developed t o resist acid. It not only resists acid, b u t it is resistant t o erosion and to rust. Ground surfaces, representing the true alloy, are practically immune from rust. The rough casting may show some rust on exposure, but this is due to impurities in the surface caused by contact of the alloy with the molding sand; this is a surface rust only and will not penetrate. The alloy is also heat-resistink, when made of suitable design. For very high temperatures, the walls must not be too thick. Castings do not distort on heating but hold their form up t o the melting point. The following data are given for “Duriron”: TABLE I-ANALYSIS (APPROXIMATE)OF Per cent Silicon 14.00 t o 14JO Manganese 0.25 to 0.35 Total -arbon 0.20 t o 3.60 Phosphorus 0.16 t o 0.20 Sulfur Under 0.05
~uRIRON
Melting point 2500° t o 2550° F. Specific gravity 7.00 Compression strength 70,000, lbs. per sq. in. Tensile strength 25 per cent less t h a n cast iron
A bar of “Duriron” was compared with a bar of equal size of the best grade of chemical pottery, under equal conditions; the earthenware test bar broke so quickly t h a t the testing machine gauge did not record any pressure. The “Duriron” bar broke under a load of 1000 lbs. By using a suspended vessel on an earthenware bar and gradually loading it with small pieces of metal and sand, a breaking test of IOO Ibs. was obtained for the earthenware bar. ~ANTmoN-Tantiron was first produced by Mr. Robert W. Lenriox of the Lennox Foundry Co., of London, England, about 1908. In 1913 the rights for the use of this alloy in the United States, Canada and Mexico were acquired by the Bethlehem Foundry and Machine Co. of South Bethlehem, Pa. TABLE 11-ANALYSIS (APPROXIMATE)OF TANTIRON
..
Silicon Sulfur Phosphorus Manganese Carbon (graphite)
P e r cent 14.00 to 15.00 0.05 t o 0.15 0.05 t o 0.10 2.00 t o 2.50 0.75 t o 1.25
Melting point about Specific gravity Tensile strength
2550’ F. 6.8 6 t o 7.tons per sq. in.
The alloy is not suitable for apparatus in which high internal pressures are to be used, unless it is strengthened by a protecting jacket. Forty t o fifty lbs. is given as the maximum working pressure for an autoclave made of Tantiron. In general, silicon iron alloy cannot be cast in rectangular shapes or flat surfaces. The chemical engineer should collaborate with the foundryman in order t o design shapes which can be produced in the foundry, and still serve the purpose of the operating conditions required. CONCLUSION
While there is still opportunity for improvement and while there is much more t o be desired in an acid-resisting material out of which to construct apparatus for the acid industry, yet, the silicon iron alloy or silicide of iron, as it has been called, has proven a boon to the acid industry; without it many things could not have been accomplished. I t is more efficient than stoneware. At best, chemical stoneware if made properly should take I O t o 1 2 weeks for its production. Castings of this alloy can be made and delivered in the same time it takes t o make castings out of cast iron. The limitation t o castings made of this alloy are those of shop and foundry alone. One company has a foundry with a furnace capacity of 7 2 tons per day. Today thousands of tons of castings made of this alloy are in use. I t is finding its way in all branches of chemical industry. Since its introduction new chemical processe? have been started which were impossible before, because of lack of suitable apparatus.
923
Silicon iron alloy is being improved upon rapidly and the time does not seem far distant when all sorts of vessels will be made of this or a similar alloy that will give to the chemical industry the ideal non-corrosive material that may be fabricated into all the shapes peculiar t o the needs of the industry. 1I08 S. 4 6 STREET ~ ~ PHILADELPHIA
COKE-OVEN AMMONIA FOR MUNITIONS By J . W. TURRENTINE
It is a very healthful reconnaissance that the nation is now making of its resources and industries in relation to national preparedness for defense. For the first time it has become recognized in this country that successful wars are t o be fought as much with mine, factory and skilled labor as with gun, battleship and armies. The nation finds itself peculiarly independent of foreign sources of materials essential t o a state of preparedness: of food materials, the metals, fuels, fabrics and-we hope t o show-explosives. Since for the manufacture of the various explosives for munitions purposes we have been using nitric acid obtained exclusively from sodium nitrate imported from Chile, the impression has come t o prevail that we have no domestic source of nitric acid, and, therefore, that in case of war with a nation of sufficient maritime strength t o enforce a blockade, we would be seriously embarrassed. Upon investigation it develops that we have a domestic source of raw materials from which nitric acid may be prepared; that this source is now large and rapidly growing, and that it is susceptible of a practically unlimited development should necessity or public exigency demand. The source meant is the ammonia recovered as a by-product in the distillation of coal for the production of coke and gas. That it has not become more generally recognized as a source of nitric acid is because it has found a ready market in that other great industry dependent on cheap nitrogen compounds, the fertilizer industry, t o which it contributes about 40 per cent of the nitrogen now consumed therein, and because commercial methods of converting ammonia into‘nitric acid are new and imperfectly understood. The explosives industry has been content with its abundant and convenient supply of raw materials obtainable from Chile and, therelore, has not demanded the development of an additional supply. The question has never before arisen in a popular way; hence, the popular misconception. In time of blockade, with Chilean nitrate no longer available, ammonium sulfate would be the main nitrogenous compound available in this country for munitions and fertilizer purposes, To what extent would this be adequate to meet the demands of the country in such an emergency? PRESEST DOMESTIC PRODUCTION OF AMMONIA The present production of ammonia in this country is from two main sources: ( I ) By-product coke ovens, and ( 2 ) coal-gas and bone carbonizing works. The production of by-product ammonia has developed from an output of 13,800 tons in 1900 t o 1g3,ooo tons in 1913. The details of the record are set forth in Table I ; likewise are presented, figures showing the production of ammonia from coal-gas and bone-carbonizing works. From these figures it is evident that the by-product oven is not only the chief source of domestic ammonia, but that it is rapidly overshadowing the other two sources. Bituminous coal contains 1.2 t o 1.34 per cent combined nitrogen. By ordinary methods of coking and from the average coal, a yield of 20 lbs. ammonium sulfate is expected per ton of coal. This is realized when the coking is done in the so-called by-products oven, that type of oven which makes possible the recovery and utilization of the surplus gas (i. e., the gas not needed in the process itself to produce the heat for the coking).
T H E JOCRNAL OF INDUSTRIAL A N D EYGINEERING CHEMISTRY
924 TABLE I-UNITED
STATES
AMMONIAP R O D U C T I O N , EXPRESSED I N SULFATB OP 2000 Lss.) Coal-Gas 83 Bone Total Per cent from Carbonizing Works Production Coke Ovens 13,80O(a) 27,600 50 14,00O(a) 29,279 52 17,64l(a) 36,124 51 17 , i 7 5 ( a ) 41,873 57 22,01l(a) 54,664 60 23,432 64 65,296
EQUIVALENT (TONS Year 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917
By-product Coke Ovens 13,800 15,279 18,483 24,098 32,653 41,864
...
62,700 50,073 75,000 86,000 95,000 130,000 153,000 183,000 220,000 234,000 376,000 (a) Estimates.
75,00O(a)
36; 609 33,327 31,50O(a) 30,00O(a) 32,00O(a) 35,000 42,00O(a)
.. ..
.. ..
99,309 83,400 106,500 116,500 127,000 165,000 195,000
... ... ... ...
..
62 60
70 74 75 79 78.5
..
.. ..
The surplus gas amounts to from 4,000 to 6,000 cu. ft. per ton of coal. Most of the coal coked, however, is coked in the socalled beehive ovens, a type of oven which makes no provision for the recovery of the surplus gas or other by-products. The
FIG I-PRODUCTION
OF C O K E I N T H E
UNITEDS T A T E S
ammonia produced in the process, in amounts per ton of coal potentially as great as 111 the by-product recovery process, is evolved 7%ith the surplus gas and with t h a t is destroyed. Likewise, other by-products, such as coal tar, the source of various substances essential t o the modern dye industry, loluol, of importance in the explosives industry, and benzol, of great value as a substitute for gasolme as a motor fuel and in other ways, are lost. These have a total value of $I jo a ton of coal coked. The coke is the only product realized from the coking in beehive ovens For every ton of coal so coked, then, we may compute the loss as SI jo. I n the gear 1914, approximately j2,000,000 tons of coal were coked in the United States, yielding 3j,000,000 tons of coke. Of this coal, 35,000,oootons, or 68 per cent, were coked in bee-
V O ~8., NO.
IO
hive ovens, while only 17,000,000 tons, or 32 per cent, were coked in by-product ovens. From the latter were obtained as by-products approximately 61,ooo,ooo,ooo cu. f t . of surplus gas, valued a t ~6,000,000;IIO,OOO,OOO gal. of tar, valued a t $ ~ , O O O , O O O ; ammonia in various forms of a total value of $7,700,000; and other by-products, principally benzol, valued a t $I,OOO,OOO;a total value of $18,000,000, in amount only 32 per cent of those recoverable from the total coal coked. These figures show that the by-products recovered in 1914 have a value of $1.13 per ton of coal, Recent developments in the industry and market have advanced this value to $1.50 per ton of coal. On the basis of the latter figure, the by-products producible, but lost, from the coal coked in beehive ovens in 1916 will be approximately $jj,ooo,ooo. The ratio of value of coke t o that of by-products is $2.37 (the value in 1914 of the coke produced from a ton of coal) to $r.jo (the value of byproducts). The increase in the amount of coal coked in the by-product ovens is due to two causes: ( I ) the increase in the total amount of coal coked, and ( 2 ) the substitution of the by-products oven for the beehive. The former increase is slower than the latter. It also fluctuates, due t o the varying prosperity of the steel and other industries using coke. I t s increase, of course, is due t o the growth of these, and t o the introduction of the use of coke into other industries. I n this connection Fig. I shows the rate of increase in production of coke. The estimate for 1916, jj,OOO,OOO tons, indicates t h a t during this year approximately 80,000,000 tons coal will have been coked. The trend of the increase, fluctuations being averaged, is shown by the dotted line. This indicates that by 1920, the production will be 60,000,000 tons of coke, requiring the coking of approximately 90,000,000 tons of coal. The substitution of the one form for the other is undoubtedly induced by the greater profits to be realized from coking in the by-products oven. S o t only is a higher yield of coke realized, but, as has been shown, the by-products represent increased revenue. This transition probably has been gauged t o keep pace with the demand for the by-products. Ammonium sulfate, for example, while being produced in increasingly great quantities, has not suffered any marked decrease in price. Coal tar is finding increasingly wide application in road building. The repo\rted development of the American dye industry, if existent, will undoubtedly increase the revenue realized i'rom the sale of coal tar, the source of most of the dyes. The sudden demand for toluol for use in the explosives industry has drawn attention t o that valuable product, The high price of gasoline has give11 impetus to the production of benzol, a product now only partially developed, which can be produced cheaply and which constitutes an ideal motor fuel. From the by-product ovens now in operation j4,000,000gal. of this commodity could be produced. The rate of substitution of the by-product for the beehive oven is illustrated by Fig, 11. The dotted portion of the line is a n extrapolation to show when this substitution will approximate IOO per cent. The present rate of increase indicates t h a t this approximation will be realized in about 5 yrs. I n Table I1 are set forth figures showing roughly the general development of the coking industry and the output of byproduct ammonia in the United States. TABLE11-DEVELOPMENTOF
THE C O K I N G I N D U S T R Y AND BY-PRODUCT A ~ T M O N IPA R O D U C T I O N (SHORT TONS) IN T H E U N I T E D S T A T E S Total Total By-products AnimoCoal Coke Beehive Coke nium Year Coked Produced Coke Tons Per cent Sulfate 5.41 1901 33 000 000 21 795 883 20 615 983 1 l i 9 900 9S:bOO 1911 53:278:248 35:551:489 27:703:644 7:847:845 22.07 1913 69 239 190 46 299 530 33 584 830 12 714 700 27.46 153,000 234,000 1916 8O:OOO:OOO 55 :000:000 37 :OOO:OOO 1S:OOO:OOO 32.7 . . . . . . 33,000,000 . . . 376,000 1917 ...... ......
Especially notable is the fact that the production capacity of the by-product plants completed and operating on ilpril I ,
Oct., 1916
THE JOURNAL OF INDUSTRIAL A N D ENGINEERING CHEMISTRY
925:
1916 is 18,000,000 tons of coke, and those now built, under construction and determined upon, by the close of the year 1917 will produce 33,000,000 tons of coke; correspondingly, the ammonia, reckoned as ammonium sulfate, produced during 1915 was 220,000 short tons;l t h a t which can be produced by the byproduct ovens completed and operating on April I , 1916, was 234,000 short tons; and finally, that to be expected by the end of 1917, is 376,000 short tons.
to supply the munitions industry, and ammonium sulfate the fertilizer industry. The conversion of ammonia into nitric acid for application to the explosives industry, however, is a distinct possibility of the future, which may result in a keener competition between the two commodities and a reduction in their price to the consumer.
THE OUTPCT FOR THE IMMEDIATE FUTURE
would be immediately available for conversion into nitric acid for munitions purposes. All of that normally entering the fertilizer trade could be so applied, since, be it remembered, the staple food and forage crops on which a nation depends in times of emergency are produced in this country without the aid of fertilizers. Agricultural production would even be restricted in case of blockade, since we normally produce a great deal more than we consume. Not more than 7 per cent of the ammonia produced now enters the refrigeration industry ; this could not be withdrawn entirely without inconvenience, though it could be reduced. T o this sum could be added that obtained from the other sources, coal-gas and bone-carbonizing works. I n contrast with the foregoing is the situation in Germany where the normal production of by-product ammonia is j j0,ooO tons ammonium sulfate (1913). This was applied to agriculture. Conditions made necessary a stimulated agricultural production instead of a restricted one, so that it was not possible to withdraw the ammonia from agriculture for munitions purposes without impairing an already inadequate food supply. Therefore, extreme measures had to be adopted to increase the supply of ammonia. By methods to be described later, whereby ammonia is converted into nitric acid, one part ammonium sulfate would produce nitric acid equivalent to 1.16 parts of sodium nitrate, from which it follows that the ammonium sulfate produced a t the normal rate of output obtaining on April I , 1916 (234,000 tons) would yield nitric acid equivalent t o 271,000 tons sodium nitrate; that estimated for 1917 (376,000 tons ammonium sulfate), 436,000 tons sodium nitrate. The importations of sodium nitrate during the year 1911 were j47,ooo tons, and during 1915 were j77,OOO tons. Kormally, it is estimated that 40 per cent of the amount imported enters the explosives industry of the country; that would be about 220,000 tons sodium nitrate, an amount decidedly less than that which could be produced from our present output of by-product ammonia. If the above quantities of ammonia were not adequate, the first step would be to replace all beehive ovens with the byproduct form, whereby the ammonia now lost from there would be saved. This would be effecting a t once (by the Government) that which is now being accomplished more slowly by the industry itself. Since the ammonia so produced could be regarded as a by-product, its cost would be negligible, the sale of the other products being a t such a price as to cover all costs of operation. The size of the investment required, then, would have no significance, since ample interest could be assured. To erect by-product ovens requires not more than $1,500 per daily ton coal capacity. Operating 360 days per year, the yearly capacity would be 360 tons coal. The proceeds from the sale of the products would be $540 for the by-products and $850 for the coke, from which must be deducted, of course, the cost of the coal, operating expenses and overhead charges. One of the by-products obtained from the proposed byproduct ovens would be combustible gas, about 5,000 cu. f t . per ton of coal coked. If so desired, and if additional ammonia were required, this gas could be used with gas engines to generate ,electrical energy for the electrical fixation of atmospheric nitrogen by any approved method. The surplus gas from a ton of coal, when so used, generates electrical energy equivalent to
The present rapid increase in the rate of transition from the beehwe to the by-product coke oven permits no other conclusion than that shortly the transition will have been realized. We can predict, then, with confidence, the amount of combined nitrogen which the immediate future w~llmake available for domestic arts and industries. Already the market exists for the coke, the main product, and undoubtedly the demand for it will continue. If the demand for coke does not increase, we can still confidently expect the recovery of the bulk of the am-
0
F I G 11-SUBSTITUTION
OF
BY-PRODUCT COKE
IN THE UNITED STATES
monia now liberated in the coking industry. On the basis of figures obtaining in 1914, that would bring the total production of by-product ammonia to 520,ooo tons ammonium sulfate; and on the basis of the estimate for 1916 (80,000,ooo tons of coal), the total would be 800,000 tons ammonium sulfate This will be realizable by the by-product oven alone. I n addition there will be a further amount of ammonia from coal-gas and bonecarbonizing works, certainly an increased amount over present production. This, then, is the production of ammonia which we may look forward to with confidence This is the development which is taking place normally, in response to ordinary economic and business laws, without apparent stimulation or artificiality. This is what we have available for normal conditions. This is supplemented, it must be remembered, by Chilean nitrate The supply appears entirely adequate for any development now contemplated. It is probable that Chilean nitrate will continue 1
This represents approximately 85 per cent of t h e total production
of ammonium sulfate of t h e country, the remaming 15 per cent, or 40,000 tons, coming from coal-gas and bone-carbonizmg works.
OUTPUT POSSIBLE UNDER EMERGENCY COiVDITIONS
In time of emergency the bulk of the ammonia produced
926
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
160 kilowatt hours; the gas produced from coking 3j,ooo,ooo tons coal (1914)would yield over 800,000 continuous horse power, which would be sufficient for the fixation of an amount of nitrogen equivalent to an additional 1,400,000 tons ammonium sulfate. The gas, being a by-product, is produced a t slight cost and the installation for the development of the power is limited to comparatively inexpensive gas engines. As a concrete proposition, in case the normal production of by-product ammonia was not sufficient for the emergency a t hand, it would be possible for the Government to install byproduct ovens and use the gas for the generation of electrical energy for the fixation of nitrogen. This could be put into operation quickly and a t a comparatively small cost. Ammonia would be produced as a by-product a t the same time, and use could be made of the coke and other products. Were the emergency postponed to a time when all the coke was produced in by-product ovens and a market had been found for the gas, use could be made of the enormous quantities of waste and low-grade coals, the lignites and even the peats available, all of which ou distillation yield ammonia and combustible gas suitable for use in gas engines. Or should it be desired t o effect a permanent and large production of ammonium sulfate, the use of coke could be encouraged by restricting the use of bituminous coal where coke can be used as advantageously. The Government itself could produce coke and sell it a t the same price as coal, reserving t o itself the ammonia and other by-products. S o t only would by-products worth $1.50 per ton of coal be conserved, but an increase of about 20 per cent in the efficiency of the coal as a producer of power would be effected. Likewise, the smoke nuisance would be abated. It is reported that such a restriction has been in effect in Germany since 1914. This is a measure which would have to be inaugurated by the people, for the producer of coal is interested in the use of more coal, not in its more economical use; and the producer cf coke is more interested in the maintenance of good prices for by-products than a larger production. It is a suggestion which is deserving of very careful consideration, for, with the coal now wastefully used, is lost enormous quantities of ammonia and benzol (and power). This rigid conservation would afford agric*ulture the best of fertilizers and the puhlic 3 s a whole an excellent motor fuel, a t a fraction of their present cost. The basis of practically all explosives is nitric acid. This, usually, is prepared from sodium nitrate. It may bc prepared
1
Vol. 8 , S o .
IO
also from ammonia. When ammonia gas and air, mixed in the proper proportions, are allowed t o flow through platinum gauze or other suitable materials, known as catalytic agents, heated to the proper temperature, the ammonia is converted into nitric acid. While the chemical reaction involved has long been understood, its recent modifications and commercial application have come t o be known as the Ostwald process for manufacturing nitric acid. It is reported that this process is in successful operation both in England and Germany; t h a t in the latter country all the nitric acid being produced is obtained by means of it. If, in our country, it could be developed to a degree of efficiency where nitric acid obtained by means of it from by-product ammonia could be made t o compete so successfully with Chilean nitrate as to exclude it from American industries, the large sum now annually expended for that commodity in a foreign market could be retained for the domestic market. Obviously the Ostwald process is of prime importance. Steps should be taken a t once to determine all the conditions surrounding its best performance. I t is claimed t h a t already it has been developed to the stage where j3 per cent nitric acid can be produced by means of it a t a cost of $0.03 per lb., inclusive of cost of the ammonia. It should be investigated thoroughly in order to establish the best technique of the operation, to further reduce the operating cost, t o further increase the yields, t o develop new and cheaper catalytic agents and to make such modifications as would render the people free of patent restrictions. By way of summary it should be added that for times of peace America has a supply of nitrogen compounds adequate for both fertilizer and munitions purposes. This supply includes imported nitrate which is adequate for the munitions indutry, and domestic by-product ammonia which contributes to the fertilizer industry. I n time of emergency, should importation be prohibited, the by-product ammonia could be withdrawn a t once from the fertilizer industry and applied to the munitions industry. This source, by normal processes, is being developed to a degree where no longer will any doubt remain as to its entire adequacy for all emergencies. Accompanying this development ~ ai111ua:Ij~to a conservation is Laking piace worth I I I ~ I Imilliuns the American people. ’
D ~ ~ P A R T V S N OF T AGRICULTURE
WASHINGTON
THE C H E M I S T IN RELATION TO FOOD CONTROL
I
Papers presented a t the 52nd Meeting of t h e .4MERICAN CHEMICAL SOCIETY, Urbana-Champaign, April 18 t o 21, 1916
THE CHEMIST IN FOOD CONTROL AS RELATING TO THE ENFORCEMENT OF LAW ny I,. R.Z. TOLMAX Chief, U. S Food a n d Drug Inspection, Central District
The work of the chemist in food control, in so far as it relates t o the enforcement of regulatory laws, is largely the obtaining of scientific evidence which may be of value in detecting the adulteration or misbranding of food products. He must not, however, be limited to the use of chemistry in obtaining this evidence, but will find that chemistry is only one of the many tools t h a t he must use and his effectiveness and the value of his evidence will be very much restricted unless he brings t o bear upon the question the assistance of bacteriology, botany, physics, and other of the sciences and arts. The adulteratioii of food products, in a general way, consists in the debasing or imitation of recognized food products, and the Food and Drugs Act defines these various forms of adulteration as follows: “The mixing of any substance, which reduces or injuriously affects the quality or strength of the article; such a? the addition of water in milk.
“The substitution of foreign material, in whole or in part; such as the mixing of distilled vinegar with cider vinegar. “The removal of any valuable constituent of the article, in whole or in part; such a5 extracting the essential flavoring oil from cloves. “The coloring of an article, so as to conceal its inferiority; such as coloring noodles yellow so as to imitate the color of eggs and conceal the fact that there is a lack of this material. “The addition of a deleterious or poisonous substance; such as the addition of salicylic acid to preserves in such quantities as might render the article injurious t o health. “The using of spoiled or decomposed products, such as moldy tomatoes in catsup.” All of these forms of adulteration above enumerated assume the existence of a n unadulterated or genuine product, and the basis of most of t h e work in t h e obtaining of evidence of such adulteration depends largely on comparison of the genuine with the adulterated article. The greatest difficulty in the work is t o get ail accurate standard with which we can compare or measure the article under examination. I t is Comparatively easy t o detect and measure adulteration if me have the article before it is adulterated t o compare exactly with t h e article aftcr
