XI. CHEMICAL PROBLEMS OF THE NAVAL STORES INDUSTRY C. F. &EX, PINEINSTITUTEOB AMERICA,INC..]ACKSONV&LH., FLORIDA
The naval stores industry, one of the key industries of the South, extends from North Carolina through South Carolina, Georgia, Florida, Alabama, Mississippi, Louisiana, and into Eastern Texas. The annual value of its products, rosin, turpentine, pine oil, tar, and pitches, is approximately $70,000,000. Of this total, rosin and turpentine amount to between $50,000,000 and $60,000,000. Approximately 300,000 people in the South are dependent upon the industry for a living. Every farmer in the pine belt is concerned with the economic perpetuation of the industry. Its products are valuable raw materials for the manufacturing of many commodities, chief among these being soaps, varnish, paper size, printing inks, linoleum, insulation materials, polishes, synthetic camphor, and many minor uses. It is of the utmost importance that this industry be perpetuated on an economic basis. There are millions of acres of idle land throughout this southeastern territory which are not needed for agricultural purposes, many of which will not grow agricultural crops profitably, but will reproduce southern yellow pine. The establishment of a naval stores industry on a profitable basis will make possible the reforestation of these lands. When these lands produce their second crop of trees, and we have every reason to believe they will, the naval stores industry will be facing a most serious problem, namely, the development of markets which will absorb the production a t profitable prices. It is estimated that this country will he capable of producing a million barrels of spirits of turpentine annually in about ten years from now. This is a big increase over the present average production of 600,000 barrels. Spirits of turpentine is divided into three classes: the gum spirits of turpentine produced from the gum obtained from the living tree; steamdistilled wood turpentine; and destructively distilled wood turpentine; the last two being obtained from stumps and "dead down lightwood." Rosin is produced both from the gum obtained from the living tree and by the solvent process from wood wastes. Pine oil is obtained in both the steam-solvent and the destructive distillation processes. The pitches are obtained from the destructive process and as a residue in the production of rosin oils.
Changes Produced in the Tree Rosin and turpentine are chemicals, and therefore their study must proceed through chemical research. Such research to be complete should 2322
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start with the tree. The cause of differing compositions of the crude oleoresins obtained from the two principal species of pine, the longleaf and slash pine, should be determined. Some trees yield larger amounts of gum than other trees of the same age, size, and general conformation. Fundamental research on the composition of the turpentines from various trees would ultimately prove of value. Some work on this subject has already been started. The crude gum as it exudes from the tree contains varying percentages of spirits of turpentine. It runs approximately one-third by weight. Much of this is lost in the various steps up to the time of stilling. What is the change in composition of this crude gum between the times of exudation and of stilling?
Spirits of Turpentine In the case of turpentine some fundamental research has been carried on in connection with the occurrence of the terpenes. However, the field is practically virgin and offers some most attractive problems, both to the organic and physical chemist and to the chemical engineer. The work naturally divides itself into two distinct classes: one dealing with the methods of production; the other, with problems of an engineering and chemical nature. Data are lacking upon the physical constants of the crude gum, the heat of vaporization and the vapor pressures of the spirits of turpentine, the application to the crude gum of the laws governing fractional distillation, and other information necessary to the proper designing of furnaces, stills, and condensers. Gum spirits of turpentine is produced commercially from two species of pine: longleaf pine (Pinus Palustris) and the slash pine (Pinus Caribaea). The original stand of pine with which the naval stores industry started was longleaf pine, and the gum from it yielded a spirits of turpentine, dextro-rotatory. The second growth shows a decided tendency for slash pine to replace the longleaf. However, the slash pine yields a turpentine which is levo-rotatory. Synthetic camphor is believed to require apinene for its efficient economic production, at least by existingmethods. How will this change in the character of pinene (dextro- to levo-) affect the use of American turpentine for this purpose? Alpha-pinene of course occurs in both the dextro and lev0 varieties. Nor should it be admitted that the present type of synthesis of camphor is the most efficient. It is possible that a contact process might be developed. Basic information, therefore, upon the composition of the present turpentine is essential. What change, if any, occurs in the composition of turpentine in storage under different conditions? What is the nature of this change? What are the oxidation and polymerization products of turpentine? Residues of distillation of old turpentine show both oxidized and polymerized products.
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There are indications that the addition of a small amount of oxidized turpentine to a paint thinner decidedly increases the adherence of the paint to the dense summer woods. What are these oxidation products? The Federal Naval Stores Act requires proper labeling of spirits of turpentine according to the three classes mentioned. The method of identification of the various turpentines in mixtures is far from satisfactory. This would, of course, also involve a study of the composition of the turpentine to identify some compound as a characteristic ingredient in each. A study of the several well-known reactions-Friedel-Crafts', Grignard's and Rtard's, as applied to the various pinenes; study of reactions relating to the production of sobrerol; of geraniol; carvacrol; of pinonic acid direct from pinene in good yieldswould offer an opportunity for good work. Would it be possible to produce from turpentine a product having a toxic value equal to pyrethrum powder? Has spirits of turpentine any value in the field of medicine or pharmacy?
Rosin When we come to rosin we 6nd even less work has been done than on turpentine. We are not sure whether we should say abietic acid or abietic acids. We are far from certain of the structure of this acid. Is the acid as found in rosin the same as occurs in the fresh gum? We know there are several acids but whether they are isomers or distinctly separate compounds is uncertain. A study of the stabilization of abietic acid, or acids, offers an attractive field. We know that some rosins crystallize with diiculty, some readily and some not at all. Why? We recognize a compound termed pyroabietic acid which does not crystallize. Apparently other polymers and isomers exist. I t is only recently that any compounds of abietic acid have been mentioned, the best known of these being an ester made with glycerin. This product has a large consumption in varnish making. Compounds with lime are being studied, and the work is proving very interesting. Studies are being started on the value of aliphatic esters of abietic acid. Ethyl abietate is now being offeredon the market and is being used as a plasticizer. A study of the compounds of the other classes of alcohols as well as nitrogen derivatives would be of value. What are the hydrogenation products of rosin or of abietic acid? Have any of the metals catalytic action on abietic acid? It is known that minute traces of copper acting as a catalyzer have caused trouble in the compounding of rubber. Possibly traces of copper coming from the still in which the rosin was made interfere with the production of many of these esters. Can rosin 6nd an increased use in the wallboard industry?
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Resene The abietic acid content of rosin varies but would probably average about uinety-three per cent. To the remaining seven per cent we assign the name resene. We know nothing of its composition. A study of this product and properties would he of value. I t has been suggested that possibly in the resenes we would find the secret of the transition to abietic acid. Some extremely interesting and valuable work has already been started on this product. Because of the lack of information available it is impossible to cover completely the field of research available on these two products, abietic acid and resene, alone, disregarding the other naval stores products. Unquestiouably, as the work is started the fields will open up and it might prove that the future will see research fields here as important and broad as those of the benzene ring. Pine Oil We find in the production of steam-solvent turpentine a product, pine oil, the chief ingredients of which are alcohols: terpineol, fenchyl alcohol, anisole, etc. We find no pine oil in the gum exuding from the tree. There is a most attractive problem in determining what steps take place in the creation of this pine oil. Is it a transition product between turpentine and rosin? If so, is there a connection between pinene and abietic acid? The Essential Problem The essential industrial problem is to greatly increase the field of usefulness for turpentine, abietic acid, resene,pine oil, and their possible derivatives, and improve the methods of production. Thus by assuring wider and more profitable markets the naval stores industry could expand until it occupied fully the position which it should take in the profitahle utilization of the timber resources of the South. I t seems only proper that the southern colleges and universities should take the lead in developing the studies of the products of the South.
