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CHAPTER I INTRODUCTION A wide range of plant and animal products is used as industrial materials. In the United States, however, only a few products account for any appreciable portion of the total. Wood is the most important, accounting for more than a quarter-million tons per year (Table 1) and over $6 billion in value at local delivery points in 1974. In addition to wood, trees produce extractives such as resin and tannin that have important industrial uses. Of the vegetable fibers, cotton is the most important with an annual production of nearly 3 million tons. The value of cotton at local delivery points is over $2 billion per year for the fiber alone in 1974. Wool is the other important natural fiber produced in the United States: more than half of United States needs or 88,000 tons are produced annually at home. Vegetable fibers other than cotton are used in small amounts only and are almost entirely imported into the United States. These include coir, kapok, jute, kenaf, ramie, hemp, sunn, abaca, sisal, and henequen. The principal vegetable oils, except for linseed oil, are used largely for food and only to a minor degree for industrial purposes. The total amount of fats and oils used for civilian consumption in the United States in 1970 for soap, drying-oil products, and other industrial products was 2.636 million pounds. Of this, approximately half was industrial uses of cottonseed oil, peanut oil, soybean oil, and imported vegetable oils; one-half was animal and fish fats and oils. Animal hides, especially from cattle constitute another important by-product that finds industrial use. If we take into account all natural materials grown for industrial use and the principal by-products of food crops, but exclude agricultural residues, it becomes evident that more than 95 percent of the renewable resources used for industrial materials is accounted for by wood. Of total value, wood probably represents approximately one-half.
Table 1 Renewable Resources Produced in the United States Primarily for Industrial Materials - 1970 Produced Imported Exported Apparent Net Consumption Wood (including bark) thousand tons Hardwood 79,538 6,043 3,698 81,883 Softwood 145,018 31,496 17,330 159,184 Total 224,556 37,539 21,028 241,067 Cotton Lint 2,541 9 966 1,584 Linters 344 17 47 314 Total 2,885 26 1,013 1,898 Wool (grease basis) Linseed Oil Animal Hides* 88 191 1,500 77 365 26 440 165 165 1425 *Figures for 1972. Source: The Outlook for Timber in the United States, U.S. Department of Agriculture Forest Service (1974). Agricultural Statistics, U.S. Department of Agriculture (1974). - 2 -
In addition, a wide ranqe of organic wastes is potentially available for industrial application. Anderson (1972) conservatively estimates that 136 million tons dry weiqht out of a total of 880 million tons annually produced in the United States could be used. Much of the plant material produced by agricultural crops is unused. For such materials as wheat chaff or corn stalks which are left in the fields, the potential for use is low. For baqasse, however, which is the residue from processing sugar cane at the mill, industrial usage is more feasible. The volume of bagasse available in the United States is estimated at 5 million tons dry weight annually. Manure is another residue with industrial-use potential to the extent that it is naturally concentrated in feedlots. At the present time, some 26 million tons dry weight are produced annually in such locations. The United States already produces a great deal of plant and animal materials for industrial use, but we have the biological capacity to produce a great deal more. We have highly developed industrial uses, but we have the technology to use renewable resources to a much greater extent to derive a much wider range of products. It is the function of the Committee on Renewable Resources for Industrial Materials (CORRIM) of the National Research Council's Board on Agriculture and Renewable Resources to sketch out this potential and these possibilities. The assessment of the biological productivity of renew- able resources used for industrial materials is rendered difficult because of insufficient data and because our potential biological productivity will depend in large part upon future governmental subsidy, governmental regulatory practices, and economic conditions that cannot be readily predicted. Fortunately, existing data are adequate to chart past trends, to assess current production levels, and to make overall predictions of biological productivity of the major industrial renewable resources as of 1985 and 2000. For the duration of the present century, the productivity of the United States with regard to renewable resources used for industrial materials will be a function derived from present circumstances modified by projected changes in the availability of resources, the level of technology, and the nature of the economic and political situation. The obvious approach to forecasting biological potential is to: (1) project the yield per unit area of a crop, (2) estimate the land area available to that crop, and (3) multiply the two to provide the estimate. We have used this technique in our report. - 3 -
It should always be remembered, though, that the area and the production per unit area are inversely related. As the acreage devoted to a given crop is increased, marginal areas are brought into production, and the yield per unit area is decreased. Conversely, as high yields are demonstrated to be both biologically possible and technologically and economically feasible, crop production is concentrated upon the best sites, and marginal producing areas are apt to be taken out of production. High yields over large areas may be theoretically possible from a biological viewpoint: they will seldom if ever be achieved because of limiting economic conditions and practical considerations of management. Our report, therefore, estimates the biological produc- tivity of industrial renewable resources in terms of current yields, existing land bases, and increments to these bases that may reasonably be forecast by 1985 and 2000. The forecast divides naturally into two parts: the sil- vicultural product of wood, and products for industry from agriculture consisting chiefly of vegetable fibers, oil seeds, wool, animal fats, tallows, and hides. Wood is not only by far the most important renewable resource used for industrial materials, but also one whose production can be greatly increased if needed. Because of the many years needed to grow a tree and because of the different statistical base and differing technologies involved, wood is treated separately from other materials. Agricultural products include cotton and other vegetable fibers; soybean, cottonseed, peanut and linseed and other vegetable oils; wool; and hides, fats, and tallows. Many of the vegetable oil crops are used primarily for food or feed and only secondarily for industrial materials. Flax (linseed oil) is the major exception. Other crops have use for industrial purposes, but their contribution to the whole is so limited that they merit only brief treatment in our quick appraisal of major industrial materials. With the major exception of soybeans, the market forâ and, consequently the production ofâindustrial agricultural crops has been declining in recent years. For these crops, therefore, demand is substantially less than productive capacity at current levels of agricultural technology and economic restraint. Furthermore, there is little reason to believe that market demand will strain biological potential by 1985 or 2000. Under these conditions, long-term estimates of productivity become a mere exercise in imagination.
Both natural fibers and natural oils have lost markets to the petrochemical industry in recent years. Of the total United States domestic demand for petroleum products of over 6.3 billion barrels (1973), only 330 million barrels or about 5 percent went into petrochemical feedstocks. A comparable amount was used in addition as energy by the petrochemical industry. Even a majcr come-back in demand for natural fibers and natural oils for industrial materials would have little effect upon total United States consumption of petroleum. REFERENCE Anderson, L. (1972) Energy potential from organic wastes: a review of the guantities and sources. U.S. Department of the Interior, Bureau of Mines Information Circular 8549, 16 pp. - 5 -
