synthesis gas (a mixture of carbon of the cheapest per unit weight as well monoxide and hydrogen), and syn- as one of the most abundant renewable thetie natural gas. These materials, in resources that we have. turn, provide raw materials identical to those used in the existing petrochemi- Summary cal industry. Plants contain a host of compounds In summary, lignocellulosic materi- that are chemically useful in making als are a resource that will always be industrial products. To develop indus- produced at the same time that we are trial products, we need to think of producing crops for food, feed, fiber, plants not just as commodities but as or chemicals. Wood wastes, harvest- "living factories" for chemical raw able field residues, and most food- materials. The major materials present processing wastes can be collected as in all plants are the three described sources of lignocellulosics. The here—oils, starches, and chemical functions of lignocellulosics lignocellulosics—and protein and permit their use either directly as naturally derived chemicals. Together, chemical derivatives or indirectly as a these materials are the source of a source of C-H-O compounds for fur- broad range of products from medi- ther chemical synthesis. As a category cines to newsprint, from jet engine of materials, lignocellulosics are one lubricants to lipstick. □

by Charles S. Taylor, Genera! Kenaf: Manager, Kenaf International, McAHen, TX, and Daniel E. Kugler, Director, Annual Fiber Office of Agriculturai Materials, CSRS, Crop Products USDA, Washington, DC Generate a Growing Response From Industry "Don't put shade on it." newer groups of interested farmers in That is the only general crop man- the Mississippi Delta, the plains of agement recommendation for the Oklahoma, the tidewaters of the Caro- steadily increasing number of kenaf linas, and the valleys of California— growers in areas of south Texas and are quickly learning that growing this southern Louisiana. They—along with annual hibiscus fiber crop is compara-

92 Part 111. Products From Nontraditionai Crops lively easy, requiring few inputs and began in the 1940's with fiber projects little management. in Cuba, Guatemala, Mexico, and El But, being easy to grow is an insuf- Salvador. Nevertheless, kenaf has ficient attribute. There must be a use been and still is a major fiber crop in and a market for the crop. The neces- Africa and parts of Asia, where the sary technologies must exist, and the long bast fibers from its bark are pro- crop must be economical to produce cessed for use in various cordage and use. Each of these attributes is im- products such as burlap, rope, and portant as a crop-to-product system twine. evolves. The principal purpose of kenaf pro- Kenaf, Hibiscus cannabinus L., is duction is to grow tall stalks that upon an annual fiber crop that is now, after maturity (in about 6 months) can be years of public and private research cut in various lengths and ground for and development efforts, in the early use in the manufacture of pulp and pa- stages of commercialization in the per products such as newsprint or United States. There are those who tissue. claim that kenaf fiber has been found in the ancient pyramids of Egypt. But Bast and Core it is still considered a "new" crop in Some uses of the fiber crop require the Americas, where its introduction separating the two distinct fibers in the

Kenaf, Hibiscus cannabinus L, is an annual David Nance/USDA 88BW1573-23A fiber crop that is now in the early stages of commercialization in the United States.

New Crops, New Uses, New Markets 93 Marvin Bagby, an ARS researcher, examines a stalk of kenaf. The long, outer bark and short, inner core fibers are processed into newsprint. USDA 88BW1884-4 ARS soil scientist L.N. Namkin examines a stand of kenaf at Rio Farms in Texas' Rio Grande Valley. Kenaf has the potential to supplement or replace wood-based paper pulp. David Nance/USDA 88BW1573-12A

kenaf stalk—bast and core. The long, stringy bast fibers of the outer bark comprise 30-35 percent of the stalk by weight and are similar to jute in ap- pearance and traditional applications. The bast is used to make cordage products and specialty pulps, and may be used as a substitute for fiberglass in certain applications. The balsa-wood-like fibers of the stalk's interior, or core, have tradition- ally been either burned for fuel by Both pulpy center and fibrous exterior of peasant farmers in Asia or Africa or bamboolike kenaf are used to produce discarded. However, they can be used newsprint and other fiber products. for a variety of products such as poul- David Nance/USDA 88BW1576-9A try litter, packing materials, and mulch.

94 Part III. Products From Nontraditional Crops Forage is another potential use lion-dollar newsprint mills) or smaller for kenaf. USDA and university fiber projects (producing poultry litter researchers in Oklahoma are testing and twine products). The current work kenaf s potential as a possible niche by industry and USDA was triggered forage crop in the Southern Plains. in the late 1970's, when newsprint This would require very different prices were increasing rapidly. Pub- farming practices, growing the crop lishers became interested in develop- for about 60 days and chopping the ing lower cost, domestic sources of immature green crop with conven- fiber for the manufacture of newsprint. tional forage equipment. The potential A process for newsprint manufac- of kenaf as a forage crop is still in the ture that was developed under the research channel, as feeding trials and leadership of USDA led to a small continued nutritional studies are being first printing by the Peoria Journal conducted. Star, Peoria, IL, in 1977. Commercial- scale trials of kenaf newsprint in 1979, Kenaf Newsprint 1981, and 1987 involved publishers, To better understand what is driving farmers, manufacturers, and USDA. the commercialization of this new Results in the pressrooms of some of crop, consider kenaf's potential as a the major newspapers in the United source of fiber for either large-scale States have greatly encouraged further industrial projects (such as multi-mil- work. In particular, the demonstration

One of the principal uses for l^enaf is in pulp and paper products, such as newsprint. USDA 92BW0827

New Crops, New Uses, New Markets 95 project led to a full pressroom run by to rural development. the Bakersfield Califomian in 1987 Other efforts to develop kenaf as a and proved kenaf newsprint to be a fiber source for pulp and paper mills market-ready commodity. generally have confronted the same is- Today ' s environmental concerns sues. Therefore, in 1991, most of the demand that chemical use in both kenaf efforts in the United States be- fields and mills be minimal. Kenaf is gan to focus more on developing mar- an annual crop fiber source, grown kets for separated kenaf fiber products with minimum production inputs by made from bast or core. local farmers (thus reducing transpor- tation costs). Its use could serve to re- Processing Methods duce the pressure on forest resources Overseas, the bark and core fibers are in some areas. Kenaf can be turned separated manually either before or af- into pulp for newsprint with lower en- ter retting (soaking in a fetid pond or ergy and bleaching requirements than canal until bacterial action loosens the those for southern pine. In fact, the bast fibers). This age-old technology Kenaf Paper Company in Willacy is dependent upon extremely cheap la- County, TX, has obtained permits al- bor and very lax environmental regu- lowing it to irrigate its fiber crop with lations. Low and cyclical world prices, the treated wastewaters discharged relatively small U.S. markets for im- from its planned chemi-thermo- ported jute, and the inability to sepa- mechanieal newsprint mill. In addi- rate the bast from the core mechani- tion, research studies at USDA's For- cally had combined to dampen interest est Products Laboratory in Madison, in exploring kenaf's potential. How= Wl, indicate that kenaf can be blended ever, major users of imported jute fi- with recycled newspapers to produce bers have initiated and maintained quality newsprint while also alleviat- communication with the kenaf team as ing pressure on local landfills. it works on gaining acceptance by the However, the proposed kenaf/re- newsprint industry. These users repre- cycled newsprint mill in south Texas sent a starting U.S. "niche" market for has been stalled by the combined ef- kenaf s separated and dry -processed fects of a glutted North American fiber products. market for newsprint, the reluctance of Materials handling has been a financial institutions to invest in a new problem with the earlier commercial agro-industry, and conditions in the kenaf newsprint trials, and in 1986 U.S. economy. Public and private de- the Kenaf Demonstration Project (a velopers remain confident that the cooperative activity between USDA project will soon be recognized for its and a task force of private sector contribution as an economically vi- interests that included Kenaf Interna- able, environmentally sound source of tional, Andritz-Sprout-Bauer, Inc., quality newsprint for regional users in Canadian Pacific Forest Products south Texas and northeastern Mexico, Limited, and the Beloit Corporation) as well as for its ability to contribute focused on finding an effective means

96 Part III. Products From Nontraditional Crops of introducing the unseparated kenaf ing stream) and that the core could be fibers to the pulp mill system. discarded. Engineering intuition also The kenaf stalks had to be reduced told him that energy and capital costs by a common hammermill operation had to be reduced if kenaf was to com- in order to "flow" into the pulping pete as a low-price natural fiber. system without roping and clogging. In this process, the grinding caused an More New Uses initial separation of the bast and core Basic economics proved Willett right fibers. The users of imported jute per- on both counts. Tinkering with com- formed some tests, and work began on bine parts and focusing on getting determining the best means of com- "clean" core, he was able to design pleting the separation process. This and test a process that achieves ad- work accelerated in 1989 with a pilot equate separation with minimal energy plant trial supported by USDA in La and capital requirements. Further- Villa, TX, using a modified cotton more, research and development work ginning process. Unfortunately, this in Delaware, Texas, and California initial attempt proved disappointing soon indicated that kenaf core had an for several reasons. Primarily, the interesting application as poultry litter. small amount of core still mixed in the Similar potential was subsequently bast made it unacceptable for continu- identified in other markets seeking ous machine runs by General Felt In- low-cost, highly absorbent sources of dustries, the main user of imported cellulose. The core has been tested as jute that was interested in kenaf. Al- a filter medium for fruit juices and en- though unsuccessful, the pilot plant gine oil, as a source of fiber in "lite" trial stimulated several independent bread dough, as an additive to drilling efforts to achieve a commercially vi- mud in oil fields, as an ingredient in able mechanical separation in which various horticultural products, as bed- both delivered cost and quality were ding in horse stables, and as a medium satisfactory to the next-stage product for oil spill cleanup. Business ventures manufacturer, who would use the bast are already under way in Louisiana fibers to make carpet padding, com- (Natural Fibers of Louisiana), Texas posite materials for interior panels, or (Kenaf International), Mississippi other materials. (Mississippi Delta Fiber Cooperative), The first separation technology was California (Agrofibers), and Delaware developed by Harold Willett, who de- (FiberCore). veloped and successfully tested the Meanwhile, new uses have begun harvesting system for the Kenaf Dem- to be identified for the bast fiber. onstration Project under a grant from Some of the prospective applications USDA in 1987-88. Willett had ob- have environmental as well as eco- served the attempt to "gin" kenaf. He nomic implications, as kenaf bast fiber could not accept the idea that there has been successfully substituted for was value only in extracting the clean fiberglass in the manufacture of bast (about 25 percent of the process- molded parts for car interiors. This

New Crops, New Uses, New Markets 97 same technology, which uses a natural which combine resources, ideas, and fiber and produces no wastewater, is people to overcome major technical, being tested in a widening range of economic, and institutional barriers. product applications, including absor- Over time, USD A has invested bent mats. more than $15-20 million of public The Kenaf Demonstration Project funds into efforts to support the re- began in early 1986 specifically to search, development, and commercial- conduct activities that would lead to ization of kenaf as a new fiber source commercialization of kenaf fibers. for industry. While it is difficult to The resulting series of collaborative quantify the contributions, it is safe to activities with industry either directly estimate that the various private coop- or indirectly helped to build today's erators involved have matched USDA foundation of 8-10 kenaf businesses in on at least a 3-to-l basis. Given the the United States and kenaf research projects already in operation and those programs in USD A and universities. soon to leap off the drawing board, it The successes are attributable largely looks as though taxpayer investment to creative and innovative partnerships in kenaf has been rewarded. Q between public and private interests.

by F.S. Nakayama, Research Chemist, Guayule Has U.S. Water Conservation Laboratory, ARS, USDA, Phoenix, AZ; W.W. Real Rubber Schioman, Jr., Instructor, Department in It, and It of Chemistry, University of Akron, Akron, OH; and S.F. Thames, Grows in tlie Distinguished University Research Professor and Professor of Polymer United States Science, University of Southern Mississippi, Hattiesburg

North and South America have two History of Guayule plants, hevea and guayule, that pro- The lesser known guayule shrub vide natural rubber for use in com- (Parthenium argentatum) is a native merce. Many of us are familiar with of north-central Mexico and south- the hevea tree (Hevea brasiliensis), SL western Texas. In fact, the Spanish native of the Amazon region that is explorers saw Indians in Mexico play- now grown primarily in Southeast ing with a bouncing ball made from Asia, because at present, this plant guayule rubber. Rubber production in provides all of the natural rubber used those days was a community under- in the world. taking; the Indians chewed the bark to separate the rubber from the rest of the plant.

98 Part ill. Products From Nontraditional Crops