industrial and engineering chemistry - ACS Publications


industrial and engineering chemistry - ACS Publicationspubs.acs.org/doi/pdf/10.1021/ie50431a003I. & E. C. Reports on...

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INDUSTRIAL AND ENGINEERING CHEMISTRY

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Concrete from Coral. Rock, sand, cement, and water are the essential materials from which concrete is made. The removal of any one of these ingredients would seriously handicap the construction engineers. The denial of two-in this instance, American rock and fresh waterwould virtually forbid the mixing of concrete: This is what was threatened in Bermuda when the Government erected one of its most important outlying military bases. Although American varieties of rock are not found in Bermuda, the islands abound in coral, the skeleton structure created by the tiny marine animal known as the polyp. Travelers have admired the beauty of coral in southern Atlantic waters and on the islands and atolls of the Pacific because the polyp is a marine architect of no mean ability. The concrete man, of course, was more concerned with the engineering qualities of coral, and it appeared highly probable that the constructors would have to use coral for the base. Coral is perforated with innumerable tiny holes; therefore it is highly absorbent and light in weight. Aggregates made with coral would have moisture-retaining properties which might introduce corrosion in the steel reinforcing. Water was another problem because i t is available in Bermuda only for household use. For this purpose rain is caught on whitewashed roofs and run into underground reservoirs. There would be none available for construction unless new catchment areas were built, which would require a great deal of time and labor. After a suggestion that water be imported had been vetoed, it was decided to use sea water. The National Bureau of Standards and the cement industry had conducted research on the use of sea water for mixing concrete, and on the basis of this work the engineers could proceed with at least some assurance. It was found that sodium and other chlorides in sea water would npt induce corrosion. Sulfides might, but these are present only in minute quantities. The contractors established a laboratory on the islands and experimented with many variations of the concrete formula. The objective was a high-impact-strength concrete for buildings, ammunition magazines, storage tanks, warehouses, and electrical conduits. A parallel line of investigation was conducted in the United States. Various

mixes were made up with coral aggregates and sea water brought in from Bermuda and cured in the usual manner. These mixes were then compression-tested against concrete made from American granite and fresh water. This work and the trials conducted in Bermuda proved that good concrete can be made from coral aggregates and sea water. Cement and water provide the mortar or binder which fills in the voids resulting from a mixture of stone and sand. Engineers in Bermuda obtained a considerable reduction in the water-cement ratio by including an admixture in their formulas, although as a rule such additions are frowned upon. The admixture is a pozzolanic compound (calcium lignosulfonate1) ; in this instance it reduced water requirements about 17%. It also facilitated control of the mixes, the setting of which was hastened unduly by Bermuda’s wind and hot sun, Concrete, testing over 4000 pounds per square inch, was obtained. The Bermuda military base project has given the construction industry an appreciation of scientific approach. By overcoming these serious raw material deficiencies, we were able to complete this essential link in our defenses shortly after we found ourselves engulfed in the cataclysm of the second world war.

Citrus Peel Oil. One of the problems in the industrial separation of citrus juices is to obtain maximum expression ofejuice without including any of the bitter oil from t h e skin. Mechanical juicers are adjusted to certain sizes of fruit, and variations in size or thickness of skin will either leave some of the juice or squeeze oil out of the skin. Peel oil deteriorates and may help to reduce the keeping quality of juice. A little oil is thought to improve the flavor. Too much oil, however, tastes unpleasant to most people and actually upsets digestion. Tests conducted a t the University of Florida have shown that 85% of the people who were asked tochoose between the flavor of juice from peeled oranges and juice to which 0.05% peel oil had been added (maximum for grade C-the limit for grade A is 0.03%) said they preferred the oil-free juice. (Continued on page 8) 1

Ersberger, F. M., and Frame, W. G., IND. EN^. CBEM.,37,688(1945).

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Ten per cent liked better the juice containlng oil, and 5% could not tell the difference. But regardless of likes or dislikes, the added oil made everybody burp. De-oilers have been used which give the juice a quick boil under vacuum with the object of removing the more volatile oil before the flavor essence starts coming off. But although the oil should theoretically be removed oompletely by a 1%distillation, a false equilibrium is encountered, and as much as 5% of the juice must be boiled off during this process. Some of the essence is recovered by returning the aqueous fraction to the juice, but the better solution is t o avoid oil in the juice in the first place, especially since the de-oiling equipment costs nearly as much as the entire juicing plant. Efforts to avoid getting too much peel oil in the juice are Iargely centered on giving the fruit a 1-2 minute treatment in hot water. This sbfhm the peel and allows the juice to be pressed out without breaking too many of the oil cells. Citrus peel oil is in fair demand as a flavoring agent (its largest use is in beverages), but less oil is produced than could be; its recovery is more or less optional in canning operations for oranges and grapefruit. Lime oil at $12.50 per pound is a different story. Formerly all lime oil was distilled, but cold-pressed lime oil wab produced in quantity for the first time only last year. Cold-pressed oil is obtained by squeezing the peel either on a screen or screw press and centrifuging the resulting emulsion. Distilled oil is recovered from de-oiling or from the concentration of press water togive a by-product molasses, but its composition is different from that of the pressed oil, and it brings a lower price. A way around the comparatively low price for orange oil ($1.40 to $1.75 per pound) has been sought by one Florida canner who makes a concentrated oil. A 10 t o 1 concentration removes most of the limonene, the terpene which constitutes about 90% of orange oil and is largely responsible for its instability. The concentrate keeps better than the original oil, and the limonene finds applicBtion as a perfume or odor killer in cheap soaps. New Chemical Markets. It is possible for a large industry to penalize itself through its own efficiency and fail t o find outlets for greatly expanded production. This is being witnessed to an extent in the petroleum industry. In addition t o providing billions of barrels of fuels and lubricants for prosecution of the war, petroleum plants performed the astounding feat of supplying 3,001,496,000 pounds of organic chemical materials during 1944, about double the amount produced in the previous year. These war materials would be surplus during peacetime, if a large share were not finding a market which did not exist prior t o 1939. The products which figured largely in this total on a volume basis were toluene, xylene, ethylene, rubber-grade butadiene, 1-butene and 2-butene mixture, propane, and propylene. The industry is shutting down the production of toluene which was required (Continued on paqe 10)

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in heavy volume for explosives. This will affect catalytic dehydrogenation and hydroforming plants which were making toluene chiefly, but similar units will remain in operation t o supply marketable products, During the war blank spaces followed “toluene” in statistical compilations of chemical production, but we now learn from the United States Tariff Commission that it attained a production volume of 134,000,000 gallons last year, compared with 43,000,000 in 1942, and these figures do not include toluene made in plants under ordnance control. It is probable that all toluene production at the peak of the war effort was eight to ten times bhe amount supplied in prewar years through coke-oven sources. Considering its value as a solvent, especially in rubber manufacture, we may require annually more than the 25,000,000 gallons which were formerly consumed each year. Through their demonstrated ability t o provide raw materials for elastomers, the petrolkum plants are assured of steady outlets for this purpose, provided national and international political influences are not permitted to handicap unduly our new rubber industry. Our synthetic needs for 1946 have been placed a t 1,200,000 tons, an increase of 200,000 tons over the current year, and approximately 600,000 tons over what is considered our normal peacetime needs. It may be necessary to suspend certain processes which have been converting butanes t o butylenes for aviation fuel; but, to supply the base stock for synthetic rubber, n-butane and n-butylenes will still have t o be made in some volume. These are processed into 1,3-butadiene, which attained the huge total last year of 488,945,000 pounds, an output expansion in only one year of 375%. The startling circumstance in connection with this is that butadiene was also being derived from alc.ohol, and that butylenes were being diverted into the production of hightest aviation fuel. Here we have a large-scale illustration of the industrial resourcefulness which contributed t o winning the war. Few people realiie that as many as thirty thousand different rubber products were supplied to the Army and Navy, and that these had to be produced in large measure from man-made intermediate materials. Through catalytic processes were obtained the olefins, isoparaffins, aromatics, and other items upon which we are certain t o establish new chemical and petroleum industries with undreamed of possibilities for the future. Thermoplastic Laminates. Phenol-formaldehyde resins have been foremost in the field of laminated plastics. When they are used in combination with ordinary fragile materials such as paper, textiles, and thin strips of wood, products of almost unbelievable strength are obtained. Heretofore a large volume of the thermoplastics (principally cellulose acetate and ethylcellulose) have entered molding, film, and other products where their toughness and color possibilities could be utilized. (Continued on page 14)

Im &E mC m Report on the Chemical World Today

I m & E m Cm Report on the Chemical World

More recently manufacturers of cellulosic resins have been engaged in an interesting line of research which may lead to the introduction of cellulose acetate and ethylcellulose in the lamitnation industry. One advantage is their ability to take a deep draw in forming operations. For example, roomy pieces of luggage may be formed in a press from cellulosic materials, and the suitcase will be light, strong, easy t o keep clean, and sound deadening. Before the close of the war a fuel tank was fabricated from cellulose laminations in teardrop design, and it was assembled without rivets, bolts, or gaskets. Blows from a sledge hammer failed to inflict any damage on this tank. The resin product has been found to possess a high energy absorption factor. It is too early to forecast the exact turn which this newest plastics development will take, but sufficient research has been conducted to indicate that combinations of cellulose acetate or ethylcellulose with wood, paper, mica, Fiberglas, cotton, and nylon will find specific applications in a number of manufacturing lines. One distinct advantage which sets cellulose acetate apart from many other plastics is its property of taking a wide range of colors. This means that artistically executed prints on cotton and rayon can be permanently fabricated into the laminate. For pigmentation, dyes such as Luxol Fast Brown R or Pink may be combined with titanium, or carbon black with aluminum powder, etc. Phenolics and urea resins are somewhat restricted in this respect. When cellulose resins are employed in conjunction with glass fiber or cotton duck, laminates of unusual strength and light weight result. A Pasadena manufacturer constructed, from the latter material and cellulose acetate, a five-passenger boat which weighed only 60 pounds. .High elastic modulus and impact strength were obtained with glass fabric as a laminating material; asbestos paper gave an elastic modulus of close to 2,000,000. Generally, the cellulose laminates appear to have excellent electrical characteristics. Thermoplastic laminates, on the other hand, possess characteristics which may disqualify them for many other industrial uses, for which the phenolic and urea maberials are better suited. It is a promising new line of development in an industry which is constantly and restlessly moving forward.

with glossy face and dull back”, but the chemist and his style-conscious following will have to rewrite that definition somewhat. Acetate is entering one synthetic satin that is “fluorescent gold and rose striped”. In a more serviceable role it finds inclusion in a foundation garment, and in still another acetate application the satin is “two-faced gold and platinum”. Some half dozen other synthetic fabrics have been introduced a t the same time. Finedenier viscose rayon of multifilament type has been made into underwear fabric with silklike qualities. Techniques for combining fibers have been developed along new lines. A taffeta of very iinedenier acetate also includes some nylon in the warp. Viscose rayon of the same fine construction is combined with acetate, and the result is an unusual satin. The finest denier acetate rayon yarn is twisted with 50-denier Cordura rayon, and a new material becomes available for evening gowns and lingerie. These combinations are considered triumphs in fabric construction. The fibers have come home from the wars to take up permanent and more profitable civilian outlets. Nylon’s longchain molecules of amine and carboxyl groupings, capable of many variations, evidently will find many fields of service outside of hosiery. Nylon is a tough crystalline material, yet soft thread1 may be made from it for wool-like materials such as socks and sweaters. Vinyon, a copolymer of vinyl chloride and vinyl acetate, can be supplied in filaments which are finer than silk. A yarn of the stuff consisting of 10 filaments mertsures only 8 denier. One of its remarkable properties is flexibility. In one form Vinyon achieves 100% recovery after stretching; hence, it is not hard to visualize applications which call for that property. Vinylidine chloride appears to have lost the coarseness which characterized its fabrics before the war. Those now manufactured for automobile upholstery are finer and softer, also stain resistant and durable. Vinylidine chloride filaments have tensile strength ranging from 40,OOO to 20,000 pounds per square inch. In the field of protein fibers, there is every justification to look for constant improvement in manufacturing properties. The casein product in the past has had one drawback-lack of strength. It possesses, however, the resilience and warmth of wool, and more recently a fiber has been developed that is finer than the natural product. New exploratory work has been resumed in textile materials with some significant results. British research conducted in rayon from alginic acid, a product of dry seaweed, may provide us with another fiber of long-chain molecules. Three mills in China are manufacturing a cloth from pms with greater tensile strength and resiliency than cotton. But what may prove the greatest textile development since the power loom is taking place in a plant in Milltown, N. J. There, textile technicians have succeeded in turning raw cotton into fabric cotton without spinning or weaving. It is not done with mirrors but with a resin binder. The resin holds the fibers in place instead of friction. (Continued on page $8)

Preview of a Revolution. Chemistry’s contributions to textiles have been glamorized and publicized with lavish abandon in the past, but there is much more to come. We have already paraded mannikins attired from head to foot with exciting test tube creations, against which the vaunted Queen of the Nile was a very plainly dressed person. Postwar now finds manufacturers and stylists getting out a new series of fabrics from synthetic fibers which strongly suggest that we are witnessing a large-scale revolution in textiles. Satins never seen before, manufactured from acetate, have just m d e their debut. According to the dictionary, satin is “A silk fabric of thick texture (Continued on page 18) 14

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Citrus Waste Waters. The waste waters from citrus canneries were originally disposed of, like any other industrial waste, by being run into streams or settling ponds. Odors of decomposition, however, soon caused trouble with the neighbors, and better disposal was required. Underground disposal has been employed in a few cases in Florida; waste waters (as well as sewage) were pumped directly into the porous lime rock which underlies most of the peninsula. But this was stopped when well water began t o taste, and methane, formed by fermentation underground, ignited, blew out wells, and broke out from fissures at the surface. Even today, several years after this practice has been stopped, gas traps are utilized on certain wells in the citrus belt. Controlled fermentation has since been used as a means of rendering the more dilute waste liquors safe for disposal, and the recovery of yeast solids is presently being considered as a protein supplement for stock feed. It has been found practical t o concentrate the waste water containing the highest solids (8%), press liquor from rind dewatering, to a molasses containing 7040% solids. Much of this molasses has been used for stock feed, but during the war when any source of carbohydrates was exploited, some of it was used by distilleries as the basis for neutral spirits. Although the price of about thirty dollars per ton for citrus waste molasses represents considerable inflation, i t is expected that the inevitable drop in price will not materially affect its production because of its importance to waste disposal. Swords and Plowshares. Despite the huge increase in catalytic cracking capacity during the war, peace found United States refiners, who represent 42% of the nation’s crude capacity, with no catalytic processes at all. These were mostly operators who had a capacity of less than 10,000 barrels per day. As such they represented an uncertain market for the sale of most catalytic units which, as a rule, are not designed to handle less than this amount daily. During the war period, over a million barrels of daily capacity were installed, and, in the opinion of petroleum men, this represented an expansion which normally would have taken fifteen years. To those refiners having installed catalytic capacity, the postwar holds RO specters, for they can make a high-premium motor fuel for competitive purposes. It is the smaller manufacturer who would have felt the pinch. Knowing this, the Houdry Process Corporation and the Lummus Company have been working on a small TCC unit to meet the requirements of a small refiner and have recently come up with equipment that efficiently refines about two or three thousand barrels of crude per day a t a cost comparable to the larger units. This was possible owing to savings in construction-integral elevator design for the spent and regenerated catalyst, elimination of vapor superheaters by increasing catalyst rates, and smaller structures for supporting the equipment. By utilizing equipment already available, costs of complete installation for high octane are said to be economical. 22