Contributions of chemistry to industry. Part II - ACS Publications

or produced, mineral deposits on the one hand and living matter on the other. As was the case in ancient Egypt, our great-grandfathers produced glass,...
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CONTRIBUTIONS OF CHEMISTRY TO INDUSTRY. PART 11* WALTERA.

SCHMIDT, WESTERNPRECIPITATION CO., LOSANGELBS, CALIPORNIA

If we go back a hundred years, we find that industry was dependent, with very few exceptions, upon the raw materials which nature either gave or produced, mineral deposits on the one hand and living matter on the other. As was the case in ancient Egypt, our great-grandfathers produced glass, porcelains, enamels, spirituous liquors, soaps, and various concoctionswhich resulted from the application of numerous fomulas. But essentially the industry of the day was dependent upon the direct utilization of the materials which were recovered as such from natural materials or natural products. Let us see what has happened since then. Probably one of the most interesting industrial contributions of the chemist was the discovery that certain materials in small quantities can be used to stimulate chemical reactions which otherwise would not take place a t an appreciable rate under the conditions of operation. The chemist refers to these materials as catalyzers and calls the operation catalysis. This discovery has been applied for the accomplishment of many useful results. For example, if sulfur dioxide gas is mixed with air and conveyed over finely divided platinum a t a somewhat elevated temperature, the platinum is not permanently affected, but the sulfur dioxide and oxygen combine t o give sulfur trioxide, which, when absorbed in water, gives sulfuric acid, and this sulfuric acid can be produced up to any desired strength. I mention this reaction because it was one of the earliest commercial applications of catalysis. It has led t o the building of an enormous number of sulfuric acid plants of much simpler design, and much greater efficiency than was the case with the earlier chamber process, although it must be said that a considerable number of chamber plants are still in operation. Above all it made possible the cheap production of a very strong acid, such as is sold under the trade name of oleum. More far-reaching in its effect was the discovery of Haber that nitrogen, an exceedingly inert and non-reactive gas, when mixed with hydrogen and subjected t o high temperature and pressure in the presence of an appropriate catalyst, reacts to produce ammonia. As i t had previously been determined that nitrogen was one of the essential foods of plant life, and whereas practically all of the nitrogen available t o man theretofore was brought from the saltpeter beds of Chile, and whereas eighty per cent of the volume of the atmosphere of the earth was nitrogen in an inactive form, * This paper was prepared for p a n t a t i o n to the Engineen Club of Los Angeles without thought of publication. The paper contains a considerable number of verbatim quotations from various reference books, hut as these references were not marked in the original manuscript, their identity has heen lost, for which the author offers an apology.

it had been the dream of chemists for years to convert the inactive atmospheric nitrogen into an available form and thus assure an adequate supply for the future. Many dire predictions of future starvation as a consequence of nitrogen shortage were made, and volumes were published painting a dismal picture of the future. The chemist came along and with a simple discovery opened up the storehouse of atmospheric nitrogen. You will be interested to know that Germany, which uses more nitrogen fertilizer per acre than almost any other country, until very recently imported prodigious quantities of Chile saltpeter. Last year, according to published statistics, Germany did not import a single pound of Chile saltpeter, but manufactured all its own nitrogen products, and exported large quantities of nitrogen compounds besides. It is interesting to note that Germany has increased its use of nitrogen as a fertilizer and, by means of this and like increases in the use of potash and phosphates, has brought . up its horticultural production to a point where this thickly populated nation is now selfsustaining, so far as food is con: cerned. I t is true that Germany stfll.imports large quantities of ;,food products, but recently I &s told by an authority on the subject that the export of horticultural products from Germany to other European nations, now balances the import of food products from the Western Hemisphere. What is true L of Germany is also true of other Catalyst tysting plant tcstini: ;trnmonia nations, and atmos. ratnlysts. pheric nitrogen fixation plants are springing up so rapidly in this country and abroad that it begins to look as though the Chile saltpeter industry might eventually be relegated to the junk pile. The ammonia formed by the direct fixation of atmospheric nitrogen can be oxidized, again in the presence of a catalyzer, to nitric acid, and nitric acid, as we all know, is the important chemical necessary for the production of explosives and other nitrification products, such as pyroxylin, lacquers, celluloid, and innumerable other materials now playing an important part in the world's commerce. Another most interesting application of catalysis is in the hydrogenation of fats and oils. A few years ago we were dependent upon animals for hard fats, such as lard. Liquid fats differ from hard fats usually in that they have a lower hydrogen content. The chemist set out to put more

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hydrogen into the molecule, and found that in the presence of a proper catalyzer, such as finely divided nickel, various liquid oils and fats would react with hydrogen, and synthetic lard was produced. One of such products is now sold under the name of "Crisco." By this discovery, humanity was set free from its bondage to slaughtered animals for its lard supply, and thousands of tons of artificial shortening materials are now manufactured from cottonseed and other vegetable oils. Useful products are also made from the once despised fish oils, and from other materials which formerly had little commercial value. As the years go by, people will accept the doctrine of the chemist that a product properly made in a factory is just as good as a natural product, no matter what the origin of the raw materials. A few years ago all wood alcohol, or methanol as it is now called, was made by the destructive distillation of hard woods. A large German chemical firm, since the war, threw into the world's market a considerable quantity of methanol, which called for no wood in its manufacture. They had found that certain hydrocarbon gases, when passed over an appropriate catalyzer under proper conditions, produced methanol so pure that it was better than any wood alcohol that had ever been on the market. Furthermore, as the product is cheaper than wood alcohol manufactured by the distillation of wood, i t looks a t the present moment as though the wood distillation industry must depend for its profits upon other products. The new process, being so important, has already been introduced in the United States through the efforts of the du Pont Company. More recently the Germans succeeded in synthesizing butanol, which is closely akin to methanol, and is used in tremendous quantities as a solvent in the paint and lacquer trade. Now comes the announcement that by a modification of the same process, they can manufacture ethyl alcohol, and apparently our gin supply for the future is taken care of. It is anybody's guess as to what this latest development will do to the tremendous fermentation industry, which has been built up by the manufacturers of alcohol, both for industrial and beverage purposes. Numerous other examples of the application of catalysis could be given, but these few will serve to show that as the result of one discovery, old industries may be replaced or seriously modified by new ones. During the past two years, much prominence has been given to the process developed by Dr. Friederich Bergius of Germany for the direct liquefaction of coal. Bergius found that under proper conditions of temperature and pressure, he could introduce hydrogen into the material a t the same time that he dissociated the heavy molecules under the influence of heat. The reactions are somewhat obscure as the material undergoing treatment is of a very complex nature and the hydrogenation reaction is superimposed upon the reactions resulting from thermal decomposition

of the heavier molecules. According to the information which has been made public, Bergius has been able to convert over half of the weight of coal subjected to treatment, to liquid hydrocarbons, working on hundreds of different samples of coal, and in a few instances he has approximated an eighty per cent conversion. Apparently these liquid products are different from the tars which are produced through ordinary distillation of coal, either a t high or low temperatures, and yield satisfactory gasoline for internal combustion engines as well as satisfactory lubricating oils. For example, one set of curves published by Dr. Bergius shows that a thousand kilograms of coal produced one hundred and fifty kilos of marketable gasoline, two hundred kilos of an intermediate fraction, sixty kilos of lubricating oil, and eighty kilos of heavy fuel oil. This process has now

reached the commercial stage and one large installation has already been built by the German chemical syndicate to produce fuel oils for the German market. I am told that this plant went into successful operation a few months ago. No data are yet available as to the cost of producing gasoline and lubricating oils from coal by this process, in comparison with the production of these materials from petroleum, and no statement can be made as to the future effectof this important development on the petroleum industry. In this connection, however, it is interesting to remember that, whereas the known oil fields are bound to be exhausted in a relatively short period of time, and new fields must be discovered, the known deposits of coal constitute a reserve for approximately two thousand years a t the present rate of consumption. What r81e the Bergius process will play in the future is still unknown, but i t is interesting to note that the

Standard Oil Company has already made arrangements with the German chemical syndicate for the acquisition of the American rights to the process. One of the spectaculax achievements of chemistry was the development of the synthetic dye industry. In 1856 Sir William Perkin treated aniline sulfate with hichromate of potash and obtained a precipitate of aniline black, from which he procured the coloring matter subsequently known as mauve. He lost no time in bringing this substance to the attention of the managers of the Pullar's Dye Works a t Perth, and they were so impressed with the product that Perkin took out a patent for his process. With the aid of his father and brother, he erected a small plant a t Greenford Green, near Hanover, England, for the manufacture of the newly discovered coloring matter, and by the end of 1857 the works were in operation. That day may therefore be reckoned as that of the foundation of the coal-tar industry, which has since attained such important dimensions. It was in Germany, however, that the aniline dye industry grew to its fullness. Perk'm cooperated in the early part of this development work in Germany, and a constantly growing number of dyes were placed upon the market. The Badische Anilin-und-Soda Fahrik spent five million dollars and seventeen years in chemical Copper Converters a t Anaconda. research before they could make indigo, but by doing so they gained the monopoly of the world's production. One hundred years ago indigo cost as much as $4.00 per pound; in 1914 i t was selling a t fifteen cents a pound. Even the pauper labor of India could not compete with the German chemists a t that price. At the beginning of the present century, Germany was paying more than three million dollars a year for indigo. Fourteen years later, Germany was selliig indigo to the amount of twelve million dollars. Besides its cheapness, commercial indigo was preferable because of its uniform quality and greater purity. Vegetable indigo contains eighty per cent of impurities. Commercial indigo is made pure and of any desired strength, so that the dyers can depend upon it. The value of the anilme dye industry is not only measured by the value of its output, for i t has produced innumerable colors of the minutest color gradation from one end of the visible spectrum to the other, colors which had never been seen before, but, what is more important, these aniline colors can be made absolutely fast and durable.

They look better, wear better and they do not injure the fabric. What is still more important, they have their origin in a dirty waste by-product of the coal industry, and the large plantations which were formerly

used for the cultivation of plants producing natural dyes are available for the raising of foodstuffs or for recreation. Recently another very spectacular industry has gown up. The chem-

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ist found that by nitrating cellulose he obtained an explosive such as gun cotton, but if the nitration was stopped somewhat short, the product was not an explosive, but a nitro-cellulose having most remarkable properties. I am referring here to the manufacture of the so-called pyroxylui products which form the basis of many commercial materials, such as celluloid, photographic films, lacquers, and many other useful materials. Cellulose can also be treated with caustic soda and then dissolved with carbon bisulfide. This liquid contains the cellulose in solution in the form of cellulose xanthate. On acidifying or heating this solution the cellulose is recovered in a hydrated form. Consequently, if this solution of cellulose is squirted out of tubes through extremely minute holes, into acidulated water, each tiny stream instantly becomes solidified into a silky thread, which may be spun and woven like that ejected from the spineret of the silk worm. What is more important these threads look like silk and, although not as strong as natural silk when wet, have certain superior properties. Since this important discovery was made, a number of processes have been developed for the manufacture of artificial silk and the industry today has taken on tremendous proportions, the production of Interior oi a silo ol the Oppau Ammonia artificial silk, such as rayon, runWorks, of the I. G . Farbenindustrie at Ludwikshafen. Storing nitrogenous lertining into tens of thousands of tons Lizers. Holds 250,000 tons total. (A simiper annum. The poor little silk lar one t o this exploded a few years ago.) worm would have had a hard time keeping up with the demands of Dame Fashion had our lady friends set out t o wear as much natural silk as they wear today in the form of a chemical factory product. Of course, it was not romantic to think of wearing a beautiful gown, the fibers of which were extrnded by a worm, hut there was the lure of importation from the orient and the product cost much money, which in itself was a sufficientinvitation for our wealthy lady friends t o wear the finer silks, but today every shop girl wears her silk stockiigs and every woman wears her silk lingerie. The cellulose which makes up the major

part of these products grew in the form of trees and after being chewed u p in huge hogging machines was subjected t o chemical purification, put into chemical solution, squirted through tiny orifices, collected, treated, and dried, spun into threads, woven into fabrics, and dyed with aniline dyes. I n 1914 the consumption of artificial silk in the United States amounted to five million pounds, while the consumption of natural silk amounted to thirty million pounds. Ten years later, in 1924, the consumption of artificial silk had risen t o forty-two million pounds, while the consumption of natural silk had mounted to forty-eight million pounds. The consumption of artificial silk has now far o u t s t r i ~ ~ ethe d consumntion of natural silk, and nearly all of this artificial silk used for domestic consumption is made in the United States. Aside from artificial silks, varnishes, and celluloid, the derivatives of cellulose find use in coatings for airplane wings, in cellophane,which is so extensively used a t present as a transparent wrapping for packages, and now they are even producing a colorless, non-breakable, transparent material to be used as a substitute for window glass. These chemical products, as has already been shown, often surpass natural products in many ways. Some have exceptional characteristics, but allof them have uniform properties which make their utilization reliable and definite. A Drawing glass. very interesting and useful improvement on natural products is that of the synthetic resins. Baekeland found that he could form a condensation product from a mixture of phenol and formaldehyde, and this product, chemically speaking, is a resin. It has superior properties, however, in that its composition is definite and consequently its characteristics are uniform. This material has found its way onto the market under the name "Bakelite," and i t is now used for a thousand different purposes; for example, in the manufacture of cigarette holders, jewelry, telephone instruments, radio dials, insulators, and innumerable other devices and paraphernalia. It has largely supplanted hard rubber as well as natural amber, and is also used in the preparation of numerous lacquers such as formerly were made from natural resins. A

Another development along this same line is a condensation product made from casein, the curd of milk. I n many metropolitan districts the consumption of cream has become so great that it is difficultto dispose of the skimmed milk. This skimmed milk is now relieved of its casein, and the casein is chemically treated to produce various materials which are sold on the market under such trade names as Galolith, Karolith, etc. This material is also used for the manufacture of cigarette holders, fountain pens, combs, toilet articles, and the like. One of the most i m ~ o r t a nresults t of chemical research has been in the field of m e t n l l u r ~ . It was only a few years ago that the induqtrial world had arailal~lrfor its needs only the various pure metals and snrh simple alloys as stcel. bronze, and hrass. 'l'odav h r c are a thousand alloys having a thousand different properties, and a great many operations which are being performed today would be utterly impossible if these alloys were not available. Take, for instance, the high-speed machine operations which have been made possible only through the development of tungsten steel, vanadium steel, andsimilar alloys. Or consider the compact high duty power plants such as we have in our automobiles. These would be absolutely impossible of achievement without modern steels' which not Distillation apparatus for producing benzene, n- e a t strength, but which are tolncne.. nanhtha. and motor fuel. . largely immune to the crystallization and cracking which limit the usefulness of ordinary carbon steel. Or consider tough manganese steel, such as is used in armor plate and guns. Leaving the steels, we come to such new products as the hardened aluminum alloys, such as are used in airplanes and dirigibles, both of which would be well-nigh impossible of achievement if it were not for the availability of structural materials which only a few years ago were entirely unknown. Mention should be made of the chrome-iron alloys which are resistant to ordinary corrosion and which now are selling on the market as stainless steel. Mention should also be made of the beautiful copper-

nickel aUoy, sold under the name of Monel metal, which is rapidly replacing German silver on the one hand and pure nickel and nickel-plated material on the other. No time is available even for a mere recitation of the names of the various alloys which have been produced during the past few years, each one of which finds its own particular use in industry. Another important metallurgical development has taken place in connection with electroplating. It is now not only possible to electroplate copper, nickel, and silver, but we have such new products on the market

Chemical stages in the rnanuiacturr of photographic film.

as chromium plate. The thin film of chromium which is applied not only gives a beautiful surface, but is entirely resistant to corrosion by most of the common chemicals which are encountered in daily life and ordinary industrial operations. It is unnecessary even to mention the enormous operations which are carried on today for the refining of metals by electrolysis, and this word "electrolysis" brings to mind the huge chemical industries which have been established for the production of chlorine and caustic soda, by the

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electrolysis of common salt, the electrolytic manufacture of chlorates, perchlorates, hypochlorites, etc. These operations suggest the large line of products which now are being manufactured in electric furnaces, both of the arc and resistant type; such materials as calcium carbide, carborundum, artificial graphite, ferro-silicon, ferro-chrome, alundum, and a dozen other products. We also have the huge aluminum industry, the manufacture of magnesium metal, calcium, sodium, potassium, etc. To give a complete review of the present-day chemical industry would he well-nigh impossible. It is only necessary to call attention to the important part which chemistry has played in the development of the petroleum industry, the fertilizer industry, the gas industry, the rubber industry, the soap industry, the paper industry, the cement industry, the ceramic industry, and so on through practically the entire list of presentday industrial operations. The development of photography would have been entirely impossible if it had not been for the work of the chemist. Today the study of photo-chemical reactions is carrying us into entirely new fields, leading toward the direct utilization of radiant energy for the production of useful chemical reactions, such as are now effected by the chlorophyl in the leaves of our growing plants, where the radiant energy from the sun produces a reaction between carbon dioxide and water in the synthesis of cellulose and the myriad other products which are found in the tissues of living plants. Although this discussion has been limited to a review of new developments, it must not he forgotten that one of the most important and farreaching contributions of chemistry to industry has been made by the analytical chemists. These men are now to be found in every factory of consequence in all civilized countries, and it is their work which is depended upon for the choice of raw material, the regulation of manufacturing processes and the control of finished products. Without these chemical watch-dogs constantly guarding the factory operations, presentday industry would lose its governor and would end in disaster. These analytical chemists do not play so picturesque a r8le as that enacted by the inventors of revolutionary processes, hut we must give them credit for making modern operations possible. No time is available for even outlining the useful results which have already grown out of the recent studies on the structure of the atom. A few years ago the electron was not even suspected. Today almost every one of us is shooting out electrons in his own home from hot surfaces in highly evacuated tubes, and by doing so is listening to concerts and speeches given at distant points, receiving these messages by virtue of the electromagnetic waves rushing hack and forth through the ether. All of this would have been impossible if it had not been for the work of the chemist.

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JOURNAL OR CHEMICAL EDUCATION

DECEMBER, 1928

The old dream of the alchemist of transmutation of base metals into gold has certainly come true--although not in the way he contemplated. The second dream of the alchemist is also coming true, at least in part. Although we have given up hope for an elixir of life which can maintain youth everlastingly, we have, through our recent researches in biochemistry, found such specific remedies as adrenalin, insulin, thyroxylin, pituitrin, and too many others to mention. We also have found those mysterious substances, the vitamins, which in infinitesimal quantities will effect the functioning of the human body, and without which human life apparently would vanish from the earth.