Webmaster's note: The following report was produced confidentially by Floyd Agricultural Energy Cooperative, outlining the economic potential for biomass tobacco as well as detailing the then-current applicable science. This report can serve as a blueprint for any organization considering the use of tobacco as a biomass resource. Many thanks to Bill Kovaric for sharing this critically important information.

Commercial Potential for Medical Protein and Co-products from Tobacco

July, 1987, Floyd Agricultural Energy Cooperative Ltd.

Rt. 3 Box 99, Floyd, Va. 24091

Summary

FAEC Ltd. (Floyd Agricultural Energy Cooperative) began as a farmer's cooperative and evolved into a for-profit agricultural biotechnology firm specializing in value added crop processing. The company currently produces ethanol for fuel and is commercializing important new pollution control technologies. Research efforts also focus on new crops and new industrial uses for crops. FAEC's staff of chemical, agricultural and mechanical engineers have designed and operated a variety of advanced biological systems.

A second Floyd-based agricultural processing company is Bio-Regional Energy Associates Ltd. B-REAL began in 1985 as an ethanol producer and is expanding into advanced wood processing technology. Both FAEC and its sister company, Bio-Regional Energy Associates Ltd., are working with Virginia Tech scientists to bring these concepts to market.

One of the most attractive new ideas for agriculture is the conversion of tobacco to a medically useful protein. FAEC Ltd. has been discussing a joint venture with Leaf Proteins International of Santa Monica, Calif. The company's principal scientist and developer of the patented LPI tobacco protein process is Dr. Samuel Wildman, retired professor of biochemistry at UCLA, some of whose publications are attached.

Fraction 1 is shorthand for Ribulose 1,5 Diphosphate Carboxylase, an enzyme found in most plants, which first received serious attention in the 1940s. Another generic name is "Rubisco." Although the enzyme is found in many kinds of plants, it is by far easiest to harvest, process and purify when derived from the tobacco plant. New developments in processing, driven by a tobacco pilot plant, could allow the development of protein extraction from kelp, spinach or other crops.

The purity of the enzyme, along with its highly nutritional amino acid composition, make it an excellent candidate for a much-needed new food source for kindey dialysis patients and others with severe gastrointestinal problems. The market size for kidney dialysis patients may be as high as $25 million.

Long range development could lead to use of Fraction 1 in parenteral (i.e.,intravenous) fluids for all kinds of hospital patients. And other coproducts with lesser-value uses, such as specialty livestock feeds, may provide a significant income stream as well.

FAEC Ltd. is among several companies which have contacted Dr. Wildman about starting up pilot facilities. LPI is interested in talking with investors in pilot facilities, as medical research may proceed as soon as sufficient quantities of tobacco protein are available.

In a new development, FAEC has recently received a proposal from Mr. Bill Drake of Austin, Texas detailing his research on the production of ethanol from tobacco biomass. As far as we have been able to determine this is a new concept, original with Mr. Drake, and if successful it promises to have a significant impact on the economics of ethanol production from plant biomass.

Mr. Drake, the former president of Santa Fe Natural Tobacco Company in Santa Fe, New Mexico, has conducted privately funded trials at New Mexico State University that have demonstrated that ethanol can be produced from conventional flake tobacco using standard fermentation methods. Mr. Drake has been corresponding with Dr. Ray Long of NCSU who supports his belief that ethanol production from tobacco produced as a biomass crop is an economically feasible approach.

Based on Mr. Drake's initial work, and Dr. Long's confirmation of the potential for successful large-scale ethanol production from tobacco biomass, FAEC will be conducting full-scale production trials after first proving the concept in small scale. Dr. Long has agreed to provide sufficient tobacco biomass for both the preliminary and full-scale trials of this concept.

TOBACCO PROTEIN: A NEW CASH CROP FOR VIRGINIA

Introduction

Tobacco is a traditional American crop introduced to settlers by American Indians. It quickly became, and has continued to be, the most important cash crop in Virginia, valued at $207 million in 1984.

Virginia ranks fourth nationwide in tobacco production, with about 116 million pounds (dry wt.) of tobacco sold in 1984-85. Cash receipts are over twice those received from soybeans, even though the acreage planted in tobacco is only 12 percent that of soybeans.

Tobacco is a key crop for small farmers which keeps in existence a reserve of farmland and operators who might not otherwise survive. This is true both in Virginia and in nearby tobacco producing states, the Carolinas, Georgia, Tennessee and Kentucky.

But profits for tobacco farmers have declined with new policies limiting allotments and providing for recovery of warehousing costs. Farmers who rely on tobacco receipts have problems similar to those who grow corn, wheat and cotton. Free competition in world markets is no longer available for the crops that American farmers can produce in such abundance. Farm problems have become so serious that farms are closing down at a rate faster than that of the Great Depression of 1930 - 1935, and many tobacco auction centers have also closed in the past year or two.

Some experts believe that farmers must become more specialized if they are to survive. That is, they will have to identify entirely new markets for agricultural products and then tailor-make new crops to satisfy these specialty markets in order to survive financially.

Fraction 1 Protein: A New Market for Tobacco

An opportunity exists to turn tobacco into a specialty crop as a source of a high-grade protein for human consumption. The intact protein will fill an important medical need and may be used for other kinds of markets in the food industry.

Leaf Protein International, a small California company, has demonstrated through the operation of a pilot plant in North Carolina that the high-grade protein can be readily obtained from young, green tobacco plants. (Wildman, 1983) The process uses off-the-shelf commercial equipment, and yields a tasteless, odorless, dry Fraction 1 protein that can be easily mixed in water.

The protein product is a chemically pure emzyme -- Ribulose 1,5 Di-phosphate Carboxylase -- which contains all of the necessary amino acids for human nutrition in a form so pure that it could be administered as a medical food with no additional processing.

The LPI process also yields coproducts that may be useful to farmers with poultry and livestock operations. The coproducts include xanthophyll, cellulose, starches, sugars and less desirable proteins. Sale of the coproducts could help finance ongoing efforts to commercialize Fraction 1 protein after poultry and livestock feed trials are performed.

Markets for Fraction 1 Protein

One highly accessible market for tobacco protein is as a medical food for people suffering kidney failure. Over 68,000 people in the United States are currently undergoing kidney dialysis treatments two to three times per week. In order to survive, they must ingest at least 20 pounds of protein per year. The purity of the protein they eat is linked to the frequency of blood dialysis. That is, protein sources should contain no sodium, postassium or other contaminants.

At present, pre-dialysis patients use amino acid compositions which are reported to be vile tasting. Each amino acid in these compositions is individually made by genetically engineered bacteria and then combined for appropriate human nutrition. The process is more expensive than the LPI tobacco protein process.

In addition to these 68,000 dialysis patients, an estimated 10 times more have severe gastrointestinal problems which require severely restricted diets.

"Fraction 1 protein from tobacco would appear to be a valuable food ingredient for the treatment of chronically uremic patients and subjects undergoing maintenance hemodialysis," according to Dr. Benjamin Ershoff, a researcher of perenteral fluids and a member of the LPI board of directors.

"It has a biological value superior to any of the available plant proteins and is comparable to the proteins of high biological value (such as found in) meat, milk, fish and fowl... It contains at most only traces of sodium, potassium and other minerals and is ideal for the preparation of low sodium diets and other diets whose mineral contents must be rigidly controlled."

With a maximum of 748,000 potential Fraction 1 users, the potential size of the market could exceed 15 million pounds, or $150 to $300 million in value. If only kidney dialysis patients adopted Fraction 1 , the potential market size could be about $25 million.

Use of Fraction 1 could substantially reduce medical costs to kidney patients in several ways. First, Fraction 1 is less expensive than the amino acid compositions. Secondly, Fraction 1 is much more palatable than amino acid compositions, and can be whipped into puddings and other meals which would encourage maintenance of the pure protein diet. Also, consistent use of Fraction 1 could, it is believed by LPI's medical experts, decrease the frequency of hemodialysis, saving patients and the government billions of dollars over the long run. While these benefits are probable given current information, a considerable amount of research needs to be performed on the human nutritional level before the benefits are certain.

Additional uses for Fraction 1 protein may involve post-operative protein sources delivered through intravenous fluids (which would require additional testing for FDA approval) and protein supplements which could find acceptance in general markets, perhaps as a health food.

An important additional use for Fraction 1 protein may be for emergency food relief in situations where time is critical and transportation problems are difficult. The Ethiopian famine of 1984-86 involved food shortages due primarily to politically imposed transportation difficulties. Airlifting dense proteins, which can then be mixed with water and/or local grains in short supply, might be a valuable new approach to these problems.

Other co-products also have important potential uses. Fraction 2 proteins from tobacco are useful in livestock and poultry feeds, and the xanthophylls from tobacco may be valuable for poultry producers who need to add colorants to fryers and layers.

Abundant free alpha-cellulose from tobacco plants may also be useful in the cellulose market, both as a feedstock for chemicals and as a potentially high-value paper material.

Scientific Background

The improvement of forage crops through extraction of proteins has been a focus of research for many decades. Research began primarily in Britain, during WWII, when protein extraction was considered for emergency food supplies (Pirie, 1942, 1971) But problems with leaf proteins from forage crops like alfalfa include: 1) high production costs and 2) undesirable odor and taste due to the presence of pigments and other contaminants (Kung and Tso, 1978).

Around 1970, two UCLA researchers reported that tobacco seemed to be an excellent candidate for economic protein extraction processes, producing high-grade crystaline Fraction 1 protein (Kawashima and Wildman, 1970). The product is a soluble single-chloroplast protein and represents half of the soluble proteins in the tobacco plant.

TABLE I

Essential Amino Acids

Comparison of Fraction 1 Protein and Other Foods

(gramsF1/100grams protein)

In 1975, Dr. Wildman proposed a simple extraction technique involving initial separations and subsequent crystalization of the protein. The procedure was tested at UCLA and at the USDA's Tobacco Laboratory at Beltsville, Md. From the tests it appeared that a low-cost method of extracting a highly purified protein form was feasible. (Wildman, 1983)

An analysis of Fraction 1 protein showed that over 99 percent was composed of pure amino acids and that its Protein Efficiency Ratio is significantly higher than that of casein. (Wildman, 1983).

As seen in Table I, Fraction 1 protein has excellent nutritional qualities. In addition, it contains no potassium, sodium, nucleic acid, lipids or carbohydrates which increase the need for dialysis in kidney patients.

It has very high foaming capacity, stability and whipping properties, and its "heat set" characteristics are similar to egg albumin or casein widely used in the food packaging industry. This means that Fraction 1 protein can be made into palatable dishes rather than simply administered as a liquid.

Fraction 1 Protein Development Efforts to Date

One of the major US advances in protein extraction techniques for poultry and feed markets came in the 1970s, when USDA's Western Regional Laboratory developed the Pro-Xan process which extracts a mixed Fraction 1 and Fraction 2 protein from alfalfa. (Knuckles, 1972) One problem with the process, however, is that the protein extract has an odor, taste and color that makes it unacceptable as a human food.

The USDA's Eastern Regional Laboratory, meanwhile, has developed a tobacco protein extraction process that aims primarily at a safer smoking tobacco through a modification of the homogenized leaf curing (HLC) process. (Kung & Tso, 1978). This protein is less valuable because acid denaturation destroys its functional properties. (Wildman, 1983) There is also some question about the value of coproducts recovered from the process.

The LPI process appears to produce the most acceptable and functional type of Fraction 1 protein, and it has been proven on a pilot scale.

A pilot plant using the LPI process was in production between 1980 and 1982 in Lucama, N.C. The plant was a joint venture between LPI, the N.C. Farm Bureau Federation and General Foods Corp. The plant produced small amounts of Fraction 1 protein in 1981 and ran on 14 occasions in 1982. Although the process was demonstrated as a success on the pilot scale, it did not produce enough Fraction 1 protein to supply medical researchers.

Financial problems intruded on the pilot plant operation. Like USDA's HLC / protein process, a major source of revenue was to have been sales of a safer deproteinized cigarette tobacco. This product, however, was not marketed to companies which might have been interested.

FAEC Ltd. first became interested in the process in 1984, when it appeared that a variety of other co-products could be marketed as a foundation for a pilot plant. For example, Fraction 2 protein can be used as a livestock feed, and the carotenes and xyanthophyl used in large segments of the poultry industry as colorants for fryers. Starch, sugar and cellulose from the tobacco plant appear to be relatively accessible for fermentation and cellulose hydrolysis.

In addition, it appears possible to use some of the same equipment needed to produce Fraction 1 protein in the off-season for other agricultural uses, especially flour from tubers (like the American artichoke.) Such a multi-feedstock, multi-product protein plant may be operated year-round to optimize capital and operational costs.

Leaf Protein International Process for Extracting Protein

LPI's patented process to extract protein from tobacco is relatively simple. The green tobacco leaves are chopped, pressed and dewatered. The tobacco liquid is centrifuged and filtered. Finally, Fraction 1 protein crystals are formed from the filtered liquid and spray dried.

Description of Products

GREEN RESIDUE is a fibrous material composed of 50% cellulose and related compounds and about 13 % protein. It is insoluble in water and is comparable in nutritional value to alfalfa hay.

GREEN SLUDGE is a mixture of starch grains, proteins, nucleic acids, fat-like compounds and pigments (chlorophyll, beta-carotene and xanthophyll). The material is insoluble in water, and has an amino acid composition comparable in nutritional value to soy protein.

CRYSTALLINE FRACTION 1 PROTEIN is a single species of protein composed entirely of amino acids with a nutritional composition equal to or exceeding the nutritional quality of casein, the standard by which other proteins used in human nutrition are judged.

Odorless and tasteless, Fraction 1 protein can be prepared free of sodium or potassium. The protein dissolves in water to the extent that 10 percent protein solutions can be made which behave in functional properties like egg white. It can be preserved indefinitely by spray drying.

FRACTION 2 PROTEINS are a mixture of proteins with an overall amino acid composition of high nutritional value. They are soluble in water.

BROWN LIQUID is a very dilute liquid in which are dissolved sugars, amino acids, vitamins and a great variety of other organic and inorganic compounds involved in the metabolism of tobacco plants.

Notes on the Process:

A) Disintegration of Plants: The aerial portions of fresh tobacco plants are placed on a conveyor for transport to the mouth of a disintegrator where plants are sprayed with a 0.5 percent solution of sodium metabisulfite in water as they fall into the pulping device. The pulp is then pumped to a screw press.

B) Expression of green juice : The pulp is pumped into a screw press where pressure from a mechanical screw forces out a green juice through a fine-mesh screen while retaining the green residue until it is discharged onto a conveyor belt. This green residue is then stored for use as an animal feed, or for cellulose, or as a tobacco smoking material. The green juice is sent on to a heat exchanger.

C) Removal of green sludge from green juice: The green juice emerging from the press is pumped through a heat exchanger so that the juice is rapidly heated to about 120 degrees F. and rapidly cooled to room temperature. This aids in the precipitation of the particulate matter, to which are attached the green pigments, insoluble proteins and other lipoidal compounds. The juice enters a continuous flow centrifuge which removes all of the starch and about 85 percent of the green particulate material which is discharged periodically as green sludge with the consistency of a very thick cream. Carotene-rich green sludge is stored or further refined for use as an animal feed. A partially clarified brown juice containing soluble proteins emerges from the centrifuge and it is then pumped to filtration units.

D) Filtration of brown juice: The partially clarified brown juice is pumped to a rotary vacuum filter which uses a filter cake made of diatomaceous earth. The filter removes the last traces of green sludge and the clear brown juice emerging from the filter is sent to a storage tank. Crystallization of Fraction 1 protein will occur within 3 to 6 hours of storage and is completed within 3 to 4 hours after the first crystals appear. If left undisturbed, the crystals will settle into a layer at the bottom of the vessel.

E) Collection and washing of Fraction 1 protein crystals: The crystals are collected by passage through a second centrifuge with the mother liquor being sent to a storage tank. They are resuspended in water followed by recentrifugation and repetition of the washing cycle. The crystals are discharged from the centrifuge as a nearly colorless suspension of about 10 percent protein.

F) Drying of Fraction 1 crystals takes place in a commercial spray drying unit commonly used for milk and other types of liquids. Care must be taken not to exceed certain temperature limits.

G) Collection and washing of Fraction 2 crystals: Fraction 2 crystals can be precipitated by adding acid to the spent mother liquor. However, this "denatures" the Fraction 2 proteins, and may not be as useful as other alternatives under investigation.

Potential Use of Products

RUBISCO (FRACTION 1 ) is an ideal candidate for medical markets because of its very high degree of purity, absence of carbohydrates, nucleic acids, sodium and potassium, as noted above. It is the absence of sodium and potassium that presents the likely prospect that this product can satisfy a large market for people who suffer from kidney failure or incipient kidney disease. The product could also be used in supplying needed protein for burn patients, patients with liver disease, and treatment of obesity or malnutrition.

A large market exists for amino acid mixtures for intravenous feeding of patients following surgery. Crystalline Fraction 1 protein could be readily hydrolyzed to equivalent amino acid mixtures that could be sold at a fraction of the cost of these amino acids.

GREEN RESIDUE: According to LPI and Farm Bureau nutritional tests conducted in Kentucky and North Carolina, this low value product is equivalent to alfalfa hay in nutrition of ruminant animals. A medium value product could be a cleaned alpha cellulose for sale to chemical and paper markets. (Note that FAEC Ltd. has access to counterwashing equipment for testing this concept). Another medium value use is an LPI patented method to convert this product into material suitable for cigarette manufacture. Such deproteinized tobacco is potentially a safer smoking material than conventional tobacco. Also, the free cellulose in the residue may be of interest as a novel feedstock for acid or enzyme hydrolysis to ethanol or many other fermented chemicals.

GREEN SLUDGE: Because of its protein and xanthophyll content, this product would be in demand by the poultry industry as a replacement for oils extracted from imported marigold flower leaves which cost about 10 cents per gram. But feeding and palatability tests are needed to establish that purified carotene and xanthophyll from tobacco leaves is acceptable for poultry feed on a commercial scale.

FRACTION 2 PROTEINS: With a favorable amino acid composition, this mixture of proteins can enhance protein efficiency in animal nutrition. Blends of green sludge, Fraction 2 proteins, green residue and brown liquid may be of interest to the livestock feed market.

BROWN LIQUID: A possible fermentation feedstock and/or additive to livestock feed, its low sugar content indicates a fermentation use as a dilutant to high sugar feedstocks. The liquid is also interesting as a feed supplement or feedstock for biological wastewater reactors.

TABLE II

YIELD PER TON FRESH TOBACCO PLANTS

CONTAINING 10 PERCENT SOLID MATTER

Product Wet Weight Dry Weight

TABLE III

PRODUCT VALUES PER TON OF GREEN TOBACCO

LPI PRODUCTION PROCESS

INTERMEDIATE SCALE PLANT (100,000 lbs F1/year)

Best Case * Conservative.*

INCOME

Green Residue $.80 x 88 lbs 80 $.05 x 88 lbs 4

Green Sludge $.24 x 69 lbs 17 $.24 x 69 lbs 17

Fraction 1 Protein $ 20 x 8.8 lbs 176 $10 x 8.8 lbs 88

COSTS

Agronomic cost per ton $1500/acre (25) (37)

Processing & Marketing ** (10) (10)

RETURNS

Net Return per ton green tobacco $238 $ 62

Net Return per acre (60-40 tpa) $14,289 $ 2,480

Net Return per season $171 million $ 744,000

Assumptions:

Plant processes 12,000 tons (22.7 million lbs) of green tobacco per year (100 tons/day); produces 100,000 lbs of F1 protein / year (834 lbs./day); entails 200 + base acres production per year (triple for rotation); wastewater handling 15,000 gallons/day; year = 120 day season.

Notes:

· Best case for green residue is tobacco smoking uses at one-half current leaf market value, while conservative case is purified cellulose for paper, chemical or energy markets. Best and conservative cases for green sludge is purified xanthophylls for poultry based on current price of Pro-Xan. Agronomic costs are based on $1,500 per acre costs with yields of 60 tons per acre (tpa) in the best case and 40 tons per acre in the conservative case.

** Processing costs vary considerably based on process options which are not fully tested. In this case, a capital cost of $960,000 is offset not only by the LPI process but also in part by other uses of the plant during the off season.

Equipment component of capital costs may also vary. For example, plate filters are cheaper than pre-coat vacuum filters; counterwash filters may be specified for chemical cellulose options; and some high-g centrifuge types may decrease need for filtration.)

Development Costs of Fraction 1 Processing Plants

A) Bench-Scale Operations:

Process: a semi-continuous centrifuge and related apparatus allow production of 10 lbs. Fraction 1 protein per day, or (optimally) 600 pounds over the summer season;

Personnel: One agronomist, one lab technician, one-half manager FTE and one-quarter secretary FTE;

Capital Costs: Building @ $15 sq. foot 15,000

Disintegrator, screw press $10,000

Centrifuge SB-7 Westphalia $37,500

DuPont centrifuge, lab equip. $24,800

Plate filters, tankage, etc. $12,000

Contracted spray drying $3,000

Subtotal $102,300

Operational Costs: Agronomic (1.6 acres) $5,000

Personnel 2.75 FTE / 6 mo. $27,500

Total Bench Scale costs: $134,800

B) Pilot Scale Operations:

Process: automatic and continuous equipment allow production of from10 to 100 pounds of Fraction 1 protein per day. (600 to 6,000 lbs. per season)

Personnel: Manager; chemical engineer; agronomist; Two lab technicians; two field hands.

Capital Costs: Capital subtotal (from A) $102,300

Added building space $ 30,000

Added filtration & drying $ 28,000

Misc. lab equipment $ 10,000 Operational Costs Agronomic 8-10 acres $ 25,000

Personnel $ 67,000

Elec., water, sewer, misc. $ 22,000

Operational subtotal $172,000

Total for Pilot Scale Option $284,300

Operations & Market Development

FAEC proposes to operate a bench or pilot scale tobacco protein process in its laboratories in Floyd, Virginia, in the heart of the burley tobacco growing region. FAEC's proximity to Virginia Tech is an advantage in agricultural research work. The company has current research contracts with Tech's Dept. of Forest Products and Chemical Engineering Dept., and would seek university experts to help in the food processing, animal science and agronomic areas of the tobacco protein project.

Medical questions concerning the marketability of Fraction 1 will need to be addressed in a series of tests at medical colleges. Discussions have taken place with several colleges, and there is interest in performing tests for the product.

The overall development of Fraction 1 protein markets is proceeding in three stages. The first stage, which was achieved at the North Carolina pilot plant between 1980 and 1982, proved that a laboratory process could be scaled up to produce crystalline Fraction 1 protein with commercial sized equipment.

The second stage will demonstrate that a large market exists for medical grade Fraction 1 protein. LPI estimates that a ton of crystalline protein will have to be produced for researchers to evaluate the benefits of the product. Tobacco protein production from a commercial scale pilot plant, such as the one envisioned by FAEC Ltd., will be needed.

The third stage will involve construction of a full fledged production facility. There may be some advantages in locating such a facility in Florida or California, where there are longer growing seasons. But there are significant reasons for locating in Virginia. The potential for byproduct markets and the desire for economic development in Virginia's tobacco producing areas could be factors in an LPI decision to proceed with development in here. Also, Virginia and other winter-freeze regions do not have insect pressures found in Florida and California, and thus would not need high levels of chemical pesticides which could accumulate up the food chain. In fact, tobacco is routinely grown without pesticides in the Blue Ridge burley areas.

LPI estimates that, based on USDA experience in concentrating leaf proteins from alfalfa (in the Pro-Xan process), a phase-three commercial production plant might have a capacity of 40 tons of raw tobacco plants per hour, with a capital cost of $10 million. The plant would produce 4.2 tons of Fraction 1 protein per day, or about 500 to 1200 tons per year, depending on the growing season. At $30 per pound, the annual gross income of such a plant would be $30 to $72 million.

Such a large scale plant would require at least 2,000 to 4,000 acres of tobacco production. At such a scale, problems may emerge with transportation, product distribution and environmental regulations. This is especially true given the nature of crystalline Fraction 1 protein. Green leaf must either be stored at low temperature or processed within 24 hours of harvesting.

Perhaps the best approach would be to build five to 10 such plants in various tobacco producing regions to spread the benefits of the technology and decrease the associated problems of large scale facilities. Spreading the impacts might also help with potential agronomic problems.

An intermediate scale plant would be profitable and better matched with farm community needs. For example, in the case used in Table III, a 100,000 pound per year (50 tons per year) plant would require only 200 acres of tobacco. And rather than dealing with 150,000 gallons of wastewater per day, the plant would generate only 15,000 gallons.

NON-MEDICAL RESEARCH GOALS

Non-medical research goals for the LPI Fraction 1 tobacco protein process involve five major disciplines to investigate uses of co-products and improve yields, harvesting methods and production techniques.

Animal Science and Bio-chemical Engineering research is essential to the immediate success of the project, since co-products without economic uses can become waste products with disposal costs.

In the process of scaling up from pilot to commercial level plant, research in Mechanical and Chemical Engineering is essential if the plant is to grow beyond rudimentary technological levels. And in the long run, agronomic and agricultural engineering research will be needed.

1) Animal Science: Co-products in livestock feed:

• Green cellulosic residue for beef cattle (weight)
• Green "sludge" (xanthophylls) for poultry (weight, color)
• Human palletability effects of tobacco as a feed

2) Bio-chemical Engineering: Co-products as industrial feedstocks

• Free cellulose as chemical or fermentation feedstock
• Sugars & starches in fermentation make-up water
• Anaerobic methanogenic reactivity

3) Mechanical & Chemical Engineering: Lowering production costs

• Best centrifuge, pump and filter types
• Best handling procedure (optimum mechanization)
• Continuous crystalization
• Product quality assurance

4) Agronomy: Improve yields

• Test tobacco varieties best suited to Virginia climate
• Improve coppice/ratoon system, cultivating techniques
• Test tobacco varieties for smoking market from coproduct (ie, dried green residue as a deproteanized tobacco)

5) Agricultural Engineering: Improve efficiency in:

• Cultivation (Coppice/ratoon system vs. others)
• Harvesting (Modular silage chopper modifications)
• Primary processing stages

Optimum Use of Co-products

There are a variety of potential uses for the four major co-products:

green residue; green sludge; brown liquid; and F2 proteins.

Green Residue

Green cellulosic residue, the first co-product separated from the feedstock stream, may have applications as a lignin-free alpha cellulose for chemical markets (such as carboxy-methyl-cellulose) or in cellulose hydrolysis to fermentable sugars (for chemicals or fuels).

These potential product lines may be tested in connection with a separate research project involving steam explosion of hardwoods for cellulose, hemicellulose and lignin products. This research is under way at Bio-Regional and Virginia Tech's Forest Products Dept. Separation and cleaning of cellulose may also be done with counterwash equipment installed at Bioi-Regional.

Another kind of cellulose product may be a de-proteinized smoking material, which could be somewhat safer than current tobacco products. LPI has patented a process by which cellulose can be removed and prepared for the smoking market. This process might be of value to a tobacco processing company which seeks an improved "safer" smoking product. Even as a blending agent, at 25 to 30 cents per pound, de-proteanized tobacco is less expensive than tobacco imported into the U.S. and far less expensive than regular leaf.

A low-value use for green cellulosic residue may be as a livestock feed. With a 13 percent protein content, its nutritional value is similar to alfalfa hay. However, its cost relative to alfalfa hay would probably be considerably lower, and resistance to its acceptance as a cattle feed would need to be overcome with feed and tasting trials at the university level.

Green Sludge

Green "sludge" is the second product from the process line in a tobacco protein plant. Organic solvent extraction can separate the products into chlorophyll, carotenes and carotenoids, solanesol and other lipoidal compounds. Purified carotenoids could find a market in the poultry processing industry assuming university level and commercial tests proved efficacy in color enhancement and no perceptible difference in taste was evident to consumers.

Costs of solvent extraction of carotenoids need to be compared with those in solvent extraction of other carotene sources. Current values at $7 per ounce of purified carotene may allow rapid development of this co-product. Optimum purification processes, along with feed and taste tests, will need to be considered.

Brown Liquid & F2 Proteins

Subsequent to Fraction 1 protein extraction, a brownish liquid with salts, sugars, amino acids, vitamins and other low molecular weight compounds remains. andFraction 2 proteins, of nearly equal nutritional value but far less purity and functionality, still remain. They may be extracted either by heat coagulation or a mild acid precipitation. However, other options need to be examined. For example, the protein content could be a useful addition to poultry or livestock feeds, and the liquid could simply be evaporated to the consistency of molasses.

The presence of sugars and starches may make the liquid useful as a diluent to high-sugar feedstocks which are typical in the ethanol fermentation industry. However, the presence of salts may inhibit ethanol or other types of fermentation.

Whether or not fermentation is possible, wastewater treatment will be necessary. While the liquid may be useful for irrigation / land application, under most state laws it would have to be treated for BOD and COD reduction.

Such treatments, whether done at the plant or at a municipal sewer, can be quite costly. One alternative is the UASB methanogenic reactor developed at the University of Wageningen in The Netherlands and recently employed at FAEC Ltd. following a graduate exchange program between Wageningen and Virginia Tech. These systems are highly cost effective, as they provide methane gas for process energy while reducing wastewater cleanup costs overall. However, tests at the FAEC laboratory will be necessary to establish the optimum parameters for UASB operation under partial or full protein plant wastewater loads.

Agricultural research goals

A considerable amount of work has already been performed at N.C. State as to optimum varieties and agronomic techniques.

Additional work on improved varieties and improving yields in various climates needs to be undertaken. Scientists at Virginia Tech's Piedmont Experimental Station are willing to provide advise to the project and help quantify research goals in improving tobacco yields.

Dr. Ray Long of N.C. State believes that 50 percent improvements in leaf productivity and protein production over current best varieties are conceivable (i.e., increases from 60 to 80 tons per acre to 120 - 140 tons per acre). Virginia Tech's Piedmont Experimental Station and N.C. State's Oxford Research Station might collaborate on varietal research in future years.

Research work into better pest and weed control methods is also needed, given the intended purity of the end product and the need to avoid insofar as possible, use of any potentially contaminating organic chemicals.