. NO.I O 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 E N G I N E E R I N G C H E M I S T R Y V O ~IO, facturing is dependent upon the development of chemical knowledge, and the manufacturers should give their assistance in every way in their power to the development of chemical knowledge. Manufacturers can do a great deal to help the universities and colleges in developing more efficient methods of instruction. They can do this by calling university and college professors into their councils and developing the practical sides of these professors so that the students in their charge will be developed along lines which will be useful to industry. The teacher in chemistry who is not in touch with practical manufacturing operations cannot properly instruct the student under him and build him up so as to make him capable, on graduation, of entering into the industries and applying his knowledge to their furtherance. Practical business men often distrust college professors. They say that they are theoretical and visionary. This in many cases is due to the fact that the practical business man has a narrow vision. Sometimes it may be true that instructors in chemistry have not a practical turn of mind. Whether this view of practical business men is true or not, the remedy is in their hands, and if they will see their broad duty, they will throw open their plants more freely to instructors in chemistry and make the education of chemists a part of their organized plan. I n other words, our colleges and universities must be used by our manufacturers and our manufacturing plants must be opened to use by our universities and colleges. Now, let me address another word to our educational institutions. They are not entirely free from criticism. It is my opinion that the educational institutions of this country should give honorary degrees t o men who have accomplished big things in the industrial world. The practice in many of these institutions is to give degrees only to those who have done original work in what is called pure science, but which work may be of no immediate practical use. It is my opinion that the man who discovers by hard labor things of practical value in the chemical world is deserving of some recognition from our colleges for his contribution to practical science. I believe that our universities and colleges should, all of them, turn more to the practical aspects of education. Many of them think only of its cultural side. Culture is desirable; no one questions this; but culture is not incompatible with an education that suits a man for the practical affairs of life. It is absurd to say that a man, to be successful in the business world, must be a boor, for its corollary is that the man of culture cannot succeed in the business world. Culture with an education that will make the student of practical use is what we want, and the educational institution that thinks only of culture is about as badly off as the educational institution that thinks only of the practical affairs of life. Our educational institutions should keep in touch with manufacturing operations, and instructors in chemistry should keep their feet upon the earth, even if we cannot expect them at all times to keep their heads out of the clouds. Since this war started it has been a wonderful thing to see how chemists generally have offered themselves t o our Government in the hope that they would be able to help in solving the practical problems confronting it. Many instructors of academic chemistry descended from their exalted positions and attempted to handle problems which they by experience have been unfitted to solve. All honor to these men; we do not criticise them, and have only praise to offer for their self-sacrifice. How much better would i t have been, however, if these men had been better acquainted with the practical matters with which they became intrusted. They came nobly to our country's assistance. They broke down the barriers with which they were surrounded, and it is a delicious hope that when peace arrives they will not allow these barriers again to be erected. To chemists generally I address this word: You have the power of influencing the opinion of those who control industries and the opinion of those who control the policy of our educational insti-
tutions. I would ask you to insist upon it that the manufacturers of our country and our educational institutions get closer together and that between them there be opened up wide avenues of intercourse. The result will be that each will be modified. Our industries will be influenced by our educational institutions, and our educational institutions will have breathed into them some of the life of the business world. We all know that this Exposition is to be a success, but success in the best sense of the term involves the power of growth. Success does not consist only in the doing of single definite things, but in the bigger sense means the doing of a series of definite things, each member of the series being of a greater value than that which immediately preceded it. My few remarks are directed to the desire that chemists and chemical industries, and expositions of this kind will have such vitality and growing power that each succeeding achievement will surpass that which preceded it, in a progressive and developing series.
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CONFERENCE ON ACIDS AND CHEMICALS September 24, 1918
DEVELOPMENT I N NITRIC ACID MANUFACTURE IN THE UNITED STATES SINCE I 9 1 4 By E. J. PRANKB, of the American Cyanamid Company
The production of nitric acid in 1914,according to the Census of Manufactures, was 78,589 tons of nitric acid of average strength and 112,124tons of mixed acid. According t o other data given in the census, these figures represent about 89,000 tons of IOO per cent nitric acid. All of this acid was produced from nitrate of soda, consuming about 160,000 tons of nitrate. The pre-war importation of nitrate of soda amounted to about 560,000 tons per annum; hence the normal consumption for purposes other than the manufacture of nitric acid was about 400,000 tons. The present rate of importation is-about 1,600,000 tons of nitrate per annum. Since very little is going into storage and the total consumption for purposes other than nitric acid manufacture has increased but slightly, if a t all, it may be estimated that a t least I,OOO,OOO tons of nitrate per annum are being converted into nitric acid a t the present time. This is equivalent to 650,000 tons of IOO per cent nitric acid of which nearly fivesixths is being used for the manufacture of military explosives. The building of the new nitrate of soda acid plants has-offered an excellent opportunity for the introduction of many improvements. The Dutch ovens under the retorts have been displaced by modern fire boxes provided with a proper arch. This change has effected a saving in coal consumption of approximately 25 per cent. The chemical stoneware from the retorts to the condensers and the glass condenser tubes have been displaced by acid-proof, high-silica iron, such as Duriron and Tantiron. The volvic-ware saucers in the towers have also been displaced by acid-proof iron. The chemical ware from the condensers to the absorption towers, and the glass lines for circulation of acid a t the sides and top of the towers, however, are retained. The absorption tower capacity has been increased about 40 per cent by the addition of more towers. Spiral rings for tower packing have taken the place of the ordinary form of packing. Important changes have also been made in operation. The average charge of 5,000 lbs. of nitrate per retort has been increased to about 7,500 lbs. The retorts, instead of being operated in batches, are now operated in rotation. Instead of 3 runs per retort per day the usual practice is now z runs per day. Temperatures are also controlled more carefully than in the past. The result of these improvements is an increase in the amount of nitrogen recovered as acid from an average of about 78-80 per cent to about 92-94 per cent of the nitrogen in the nitrate
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of soda. At the same time the labor requirement has been somewhat decreased. A good beginning also has been made in the recovery of nitrose gases produced in the various nitration operations. In some of the systems that have been devised as much as one-half of the fumes are being recovered. The collection of the gases from the many nitration units, however, is still a serious problem. While the aggregate amount of acid that is being recovered is large, i t represents only a small fraction of the acid gases that are being wasted. In the ordinary nitration operation as carried out a t present about one-tenth or one-twelfth of the nitric acid is wasted in the wash waters, while on an average about oneeighth is lost as fumes, of which one-half is recovered in plants that are equipped with recovery systems. Nitric acid by direct combustion of air by the arc process has not had any important development as yet in America. Three small plants, more or less on an experimental scale, have been built in the United States and operated for short periods. The produetion of these plants thus far has been negligible. The total annual capacity probably does not exceed two or three thousand tons of nitric acid per annum. Nitric acid by the oxidation of ammonia has received a considerable and important development since the outbreak of the war. In 1914there were no ammonia oxidation plants in this country. At the present time there are under construction ammonia oxidation plants with a capacity equal to about 225,000 tons of IOO per cent nitric acid per annum. The first commercial-sized oxidation plant was established in July 1916,a t the Ammo-Phos Works of the American Cyanamid Company, a t Warners, New Jersey. Six catalyzer units were installed, each with a presumed capacity of 14 lbs. nitric acid per hour. Improvements in the design of the catalyzer and in methods of operation have brought the capacity to over 40 lbs. of nitric acid per hour. The catalyzer used is a single fine platinum gauze with a n area of about 2 sq. ft., electrically heated. Over a period of 2 years two of these units have supplied the nitric requirements of the 60,000 ton sulfuric acid chamber plant a t this works. The ammonia is taken directly from cyanamid autoclaves producing about 30 tons of ammonia gas per day, used mainly for aqua ammonia manufacture. This plant has served for several months as a training school for the instruction of operatives for the Government cyanamid-nitrates plants Hence, more extensive records are available than would normally be the case. As an example of the normal operation of the catalyzers on ammonia taken directly from the autoclave mains, the following figcres are quoted verbatim from the records for the week July 13 t o 19, 1918. Each value is the average of determinations of two chemists working independently, with the exception of those marked (*) which are determinations of one chemist only. CATALYZER No. 5 Date July 13 July 13 July 13 July 13 July 14 July 14 July 15 July 15 July 16 July 16 July 17 July 17 July 18 July 18 July 18 July 19
Time Efficiency 96.2 2.35 A.M. 98.5 8.40 A.M. 93.1 5.20 P.M. 96.0 11.50 P . M . 97.4 5 . 5 0 A.M. 94.8 5.10 P.M. 95.0 10.35 A.M. 5 . 1 5 ~ ~ .9 5 . 8 95.4 1.50 A.M. 95.4 11.20 A.M. 92.1 1.10 A.M. 92.3 1.00 P.M. 93.4 12.50 A.M. 92.6 10.55 A.M. 91.9 8.00 P.M. 93.6 9.50 A.M.
Average for week ... .
CATALYZER No. 6 Date Time Efficiency 5 . 3 0 A.M. 13 90.0 13 93.0 1 .,lo P.M. 13 93.4 8.40 P.M. 14 93.0 2 . 5 0 A.M. 1 .oo P.M. 14 94.2 14 10.15 P.M. 93.2 95.6 8 . 15 A.M. 15 90.7 15 2 . 3 0 P.M. 92.6 15 11.30 P . M . 8.00 A.M. 90.0 16 93.0* 8 . 2 5 P.M. 16 90.9 17 9.30 A . M . 94.0 17 8 . 2 0 P.M. 92.0 18 7.40 A.M. 91.6* 18 5.1OP.M. 4.15 A.M. 93.0 19
~
94.5
Average for week.
. . ..
92.5
The cyanamid-nitrates plant a t Muscle Shoals, Alabama, will use the electrically heated, single gauze catalyzer. It will produce approximately go,ooo tons of 100per cent nitric acid per annum. The plant is expected to go into operation about November I , 1918. .The cyanamid-nitrates plant near Cincinnati and the
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one near Toledo, Ohio, will also use the same process, each producing a t one-half the above rate. They are expected to be in operation early next spring. The Government experimental plant a t Sheffield, Alabama, known as Nitrate Plant No. I , which will make about 15,000 tons of nitric acid per annum, has adopted a non-electrically heated multiple screen, consisting of several layers of platinum gauze, welded together a t points, and rolled into the form of a cylinder. The ammonih-air mixture flows outwards through the screen a t a rate several times as fast as with the electrically heated single screen. After the oxidation has been started by external application of heat the temperature is self-sustaining from the heat of reaction. In view of the perfect control obtainable with electrical heating, the cost of the electric energy consumed, amounting to about one-third of one per cent of the present market value of the nitric acid, may be regarded as negligible. As to the single versus the multiple screen the efficiencies cited above as examples of normal operation of electrically heated single screens are believed to represent the highest standards yet attained in t h e practical operation of ammonia catalyzers. It is understood that the Semet-Solvay Company has a n ammonia oxidation plant a t Syracuse, New York, using t h e multiple screen without electrical heating. This plant is producing several tons of sodium nitrite per day. Information regarding efficiencies is not available. I n addition t o the plants above mentioned the Navy Department, about two months ago, decided to build a plant a t Indian Head, Maryland, for fixing nitrogen by the modified Haber process used a t Plant No. I . All the ammonia produced will be oxidized to nitric acid, yielding about 30,000 tons per annum. Considerable work is also being done on the use of catalyzers to hasten the conversion of the nitrose gases obtained from t h e catalyzers into nitric acid. The object is t o reduce the amount of space required for reaction chambers. The experiments along this line show promise of early success. The nitric acid producing rate in the spring of 1919 will be about 650,000 tons from nitrate of soda and about 225,000 tons by oxidation of ammonia obtained from the air, a total of 875,000 tons of IOO per cent nitric acid. This is about nine times the pre-war normal consumption. In 1914 the industrial explosives industry consumed about 50,000 tons per annum, while all other uses took only about 40,000 tons. The only notable increase in consuming ability since 1914,aside from military explosives, has been in the dye industry. I n 1917 it was estimated that 30,000tons of dyes were produced in America, equal to the total 1914 consumption. The production will probably increase somewhat further, but a t most could hardly consume more than 30,000 or 40,000tons of concentrated nitric acid, With a producing rate of 875,000 tons and a consuming ability in peace times of 125,000or possibly 150,000 tons, it is evident that over four-fifths of the nitric acid producing capacity will have to be shut down as soon as peace conditions are established. The successful development of the ammonia oxidation process raises the question whether this may not become the principal source of nitric acid in the future. While a categorical statement cannot be made, some of the major factors may a t least be pointed out. The cost of converting nitrate of soda to concentrated nitric acid is just about equal to the cost of converting autoclave ammonia gas to concentrated nitric acid, interest and depreciation included in both cases. Ammonia gas, however, is a cheaper form of nitrogen than is nitrate of soda. It is cheaper by the amount of sulfuric acid required to fix the ammonia gas in the form of sulfate of ammonia, for nitrate of soda and sulfate of ammonia in the past have always sold a t about the same price per pound of nitrogen. They will probably
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be sold on a competitive basis after the war, or if there is any difference, the ammonium form will probably be the cheaper. The differential between ammonia gas and sulfate of ammonia, then, will make a difference of about 15 to 20 per cent in the cost of the nitric acid, in favor of ammonia oxidation. The fact that the nitrate of soda acid plants are being amortized during the war and are conveniently located for peace-time industrial uses, while new ammonia oxidation plants would have t o be built a t these same points in order to avoid transporting acid, is relatively not very important, because the interest and depreciation charge saved by amortization of the nitrate of soda acid plants is only about 4 per cent of the normal cost of the acid. The decisive factor will probably be simply the question whether the difference in cost of acid by the two processes is a sufficient incentive t o overcome the inertia of human nature against changing existing practices.
POTASH SYMPOSIUM September 25, 1918
RECOVERY OF POTASE FROM KELP B y C. A. HICGINS.of the Hercules Powder Company The recovery of potash from kelp, and the utilization of kelp ashes, principally as a fertilizer, is an art that has long been practiced. Many centuries before the German Syndicate began t o market potash salts from their Stassfurt mines, the crofters around the rocky shores of Scotland and the northern coast of France had burned the drift kelp as a fuel, and scattered the ashes over their land as a fertilizer. The great success which resulted from the use of this kelp ash on the land caused a rapid expansion in the business of kelp harvesting, until about the beginning of the 19th century quite a flourishing industry had already sprung up. The opening up of the German potash mines, however, about the middle of the 19th century, began to flood the market with potash a t a price far below that a t which the old kelp burners could produce it, and although the kelp potash industry still struggled along in isolated parts of the coast among the Scottish crofters, and t o some extent in Japan, it may be said that the German production killed the kelp industry, which had up to that time attained fairly considerable proportions. The outbreak of the present war, however, drove potash users t o look for new sources of supply, and naturally one of the first to come t o their attention was kelp. Previous to the outbreak of the war many writers had drawn attention t o the huge perennial beds of kelp which grow practically uninterrupted all along our coastal waters on the Pacific side, from the Mexican line to Alaska, and around the scattered groups of islands which lie close to the California shore. These vast fields of kelp seemed t o offer inexhaustible supplies of potash, which according to the preliminary survey made by the Government, bade fair to supply far more than the normal requirements of our country for the indispensable muriate of potash. All that remained was to devise economical means for harvesting these vast beds and drying and reducing the kelp t o a suitable condition for transportation and use as a fertilizer. Within a few months, therefore, of the cutting off of the German muriate, various large companies were prospecting the Pacific Coast for suitable sites on which to erect plants for the harvesting and extraction of potash from the Pacific kelp. The earliest attempts a t harvesting were very crude, and involved a good deal of manual labor. Men in flat-bottom scows would reap the weed by hand with large sickle knives and burn it in a rather primitive way. The ash was afterwards sold to the big fertilizer companies a t a price based upon the potash content, which generally ranged around 15 per cent KnO. Later, however, modern methods were installed for the harvesting of kelp. Large flat-bottom, steam or gasoline-propelled scows were equipped with a mechanical reaping device and band con-
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veyors which cut the kelp and conveyed it in one operation into the tanks aboard the harvesting vessel, a t very much less expense than that involved in the old method of hand cutting. These harvesters, when filled, then proceeded to shore under their own power and discharged their contents into hoppers a t the plant, which in turn fed series of mechanical dryers, where the kelp leaves were dried and partly incinerated by passage through revolving drums heated by oil burners. The dried incinerated kelp leaves were next ground and sacked, and were then ready to be shipped to the fertilizer factory. Some attention is paid in the drying process t o insure that a minimum of the potash and nitrogen content of the kelp is lost by the destructive distillation effect of the drying equipment. That, briefly, is the method now in use in plants where potash is considered as the only valuable constituent of the kelp. Experience has shown, however, that this process of producing potash and realizing the values of kelp is very expensive, and will exist possibly just so long as the war and the present high price of potash last. A few figureswillshowthe status of the kelp ash industry in this regard. Using the modern harvesting methods that I have already briefly touched upon, experience shows t h a t it costs around $1.10 to harvest and bring a ton of. kelp leaves ashore. Analyses show that the average potash content of the raw kelp as harvested in California coastal waters is about 1.3 per cent KzO, which means that it costs about $85.00 to bring in the green kelp equivalent t o 2000 lbs. IOO per cent KzO. To this, of course, must be added the cost of drying these kelp leaves, which contain about go per cent of moisture, and by reason of their gelatinous and cellular structure present quite a problem in desiccation. All indications seem to point very clearly to the fact, therefore, that any industry which looks to the production of potash from kelp on a permanent peace-time basis must reduce its costs very considerably, or produce valuable byproducts in the same process which in turn will effect a reduction in the cost of the potash. Along these lines certain investigators have suggested, as far back as a century ago, that the peculiar algin bodies present in kelp might be profitably recovered and used in certain operations in place of gelatin, for the sizing of paper and textiles, the proofing of cloth, and in the production of rubber substitutes and admixtures. Another interesting suggestion is that of Prof. T. C. Frye, who made a conserve by first leaching out the potash and soluble salts and afterwards soaking the kelp in cane sugar solution flavored with lemon. In Japan a kind of sour pickle with vinegar is made from the fleshy parts of the kelp. The kelp fiber when compressed and dried also forms a hard substance resembling ebonite or vulcanized fiber, and a t least one concern is working along these lines a t the present time. The production of by-product iodine from kelp, however, has long been a practical proposition, although hampered somewhat by the competition of by-product iodine from the Chilean nitrate fields The biggest practical advance in the economical production of potash from kelp was made in the year 1915, when the Hercules Powder Company started the construction of large gasolinepropelled marine kelp harvesters and a factory near San Diego, California. This equipment was designed primarily for the production of acetone, potash, and iodine from kelp. Kelp as a source of acetone was something entirely new to the chemical industry, and chemists $11 over the world have watched the growth and development of the undertaking with great interest. The plant since its inception has rapidly increased the number and range of its products and has placed upon the market some new materials which are full of industrial promise. Reduced to its simplest terms, the basic principle of this process of kelp reduction lies in the destruction of the cellular tissue of the kelp leaf by fermentation, bringing the potash into solution, and producing acetic acid as the product of the
