At the turn of the century, most nonfuel industrial products—dyes, inks, paints, medicines, chemicals, clothing, synthetic fibers, and plastics—were made from trees, vegetables, or crops. By the 1970s, organic chemicals derived from petroleum had largely replaced those derived from plant matter, capturing more than 95 percent of the markets previously held by products made from biological resources, and petroleum accounted for more than 70 percent of our fuels (Morris and Ahmed, 1992). However, recent developments are raising the prospects that many petrochemically derived products can be replaced with industrial materials processed from renewable resources (Kaminsky 2004). Scientists and engineers continue to make progress in research and development of technologies that reduce the real cost of processing plant matter into value-added products. Simultaneously, environmental concerns and legislation are intensifying the interest in agricultural and forestry resources as alternative feedstocks. Sustained growth of this developing industry will depend on developing new markets and cost-competitive bio-based industrial products (Morris and Ahmed 1992).

Numerous opportunities are emerging to expand industrial needs through the production and processing of biological materials. Todays bio-based products include commodity and specialty chemicals, fuels, and materials. Some of these products result from the direct physical or chemical processing of biomass—cellulose, starch, oils, protein, lignin, and terpenes. Others are indirectly processed from carbohydrates by biotechnologies such as microbial and enzymatic processing. The gross annual sales of these biochemicals in 1994 exceeded $13 billion US (Datta, 1994). Analyses of historical and present market growth rates suggest that the worldwide market for specialty chemicals will grow 16 percent per year (Datta, 1994).

A wide range of bio-based industrial products and technologies will be introduced to diverse industrial markets. Ethanol and oxygenated chemicals derived from fermentable sugars will be key precursors to other industrial chemicals traditionally dependent on petroleum feedstocks. In the long term, with advances in genetic engineering and large-scale fuel production from lignocellulosic plant materials may become cost competitive with petroleum fuels(RBEP 2004). In other cases, bio-based technologies such as enzyme catalysts are promising replacements for more hazardous industrial chemical processes. Increasingly, niche markets will be sought for a wide array of custom-engineered plant polymers not available in petrochemical-based products(Stricker and Smith 2004).

KEY BIOBASED PRODUCT AREAS:

• Intermediate and Specialty Chemicals
• Bio-based Materials

Specialty chemical markets represent a wide range of high-value products. These chemicals generally sell for more than $2.00 per pound. Although the worldwide market for these chemicals is smaller than those for bulk and intermediate chemicals, the specialty chemicals market now exceeds $3 billion US and is growing 10 to 20 percent annually (Datta, 1994). Examples of bio-based specialty chemicals include bioherbicides and biopesticides; bulking and thickening agents for food and pharmaceutical products; flavors and fragrances; nutraceuticals (e.g., antioxidants, noncaloric fat replacements, cholesterol-lowering agents, and salt replacements); chiral chemicals; pharmaceuticals (e.g., Taxol); plant growth promoters; essential amino acids; vitamins; industrial biopolymers such as xanthan gum; and enzymes.

Specialty chemicals can be made using fermentation and enzymatic processes or directly extracted from plants. Genetic engineering has now made possible microbial fermentations that can convert glucose into many products and can yield an essentially unlimited diversity of new bio-chemicals (Zeikus, 1990). Likewise, one could engineer plants to produce some of these same chemicals. Furthermore, industrial researchers are discovering that plants can be altered to produce molecules with functionalities and properties not present in existing compounds such as chiral chemicals. It is anticipated that advances in biotechnologies will have significant impacts on the growth of the specialty chemicals market (CLS 2000).

• Bio-based Acids
• Bio-based Oils
• Specialty Chemicals

Acids are a vital component of industrial production. Used in everything from the production of food preservatives, plastics, and medical discoveries, increasing the feedstock for the production of acids is vital for the United States to stay economically competitive in the global market. As technology advances and the understanding of acid production becomes more clear, the use of woody biomass for the production of specific acids becomes a more economically attractive solution over the current petroleum and high energy costing methods.

These are some important bio-based acids that can be recovered from forest residues:

• Acetic Acid
• Fatty Acids
• Itaconic Acid
• Lactic Acid
• Succinic Acid

Itaconic acid can be fermented from starch derived glucose and sucrose but fermentation from xylose has so far offered the potentially best economically efficient route (Brown 2003). The acid is used in the production of synthetic latexes to improve emulsion stability and adhesion. Many paper-coating and carpet-backing industries are the primary user of the product but derivatives of the acid are used in medicine, cosmetics, lubricants, and herbicides. Currently, the high costs of production have limited the use of itaconic acid (EI 2003).

Research into lower-cost production processes could enable itaconic acid to compete economically with petroleum based methyl methacrylate (MMA) in the clear plastics and shatterproof replacements for glass, such as Plexiglass and Lucite, and in acrylic paints. MMA markets are roughly 680,272 tonnes per year at a market price of $0.50 US per pound in 2002 (EI 2003). Other itaconic acid derivatives could be competition for pressure-sensitive adhesives. The market for this product was 136,054 tonnes and sold for $3.00 per pound in 2002 (EI 2003).

The fermentation of glucose from plant starches produces lactic acid. In the United States, nearly 72 million pounds are used yearly, mainly in the food and beverage service. Chemical companies have invested substaintal capital in identifing potential derivatives of lactic acid that can serve as bio-based alternatives to chemicals currently produced from petroleum. Currently the largest source of lactic acid results from the fermentation of corn. Advances lowered 2002 production costs by half; enabling lactic acid to be sold for $0.25 US per pound (EI 2003).

Following the leads of Cargill, Dow, Genencor, and the National Renewable Energy Laboratory, federal researchers are seeking to expand lactic acid fermentation processes into lignocellulosic feedstocks. Using an enzyme system, Genencor and NREL are enabling a system that would show a 10-fold improvement in the production of lactic acid from woody plant material. Others at the Department of Energy are working with advanced hydrolysis and microorganisms to ferment lignocellulose components directly.

Five bio-based products have been commerically identified from derivatives of lactic acid. Polylactic Acid (PLA) is a themoplastic polymer commercialized by Cargill Dow. With a 136,054 tonne capacity plant in Blair, Nebraska the company sells it as NatureWorks PLA to be used for consumer goods and food packaging as well as fibers for apparel, bedding, and carpet. In 2000, over 9.5 million tonnes of thermoplastics were used in packaging. Cargill Dow is projecting a potential market of 3.6 million tonnes for their PLA product by 2020.

Ethyl lactate is an environmentally friendly solvent that has recently been commercialized by Vertec BioSolvents. Used mainly in industrial applications such as specialized coatings, inks, and cleaners, the product could displace 80 percent of the 4.5 million tonnes of solvents used per year. Selling prices for ethyl lactate were still nearly 30 percent higher than for competitve petroleum standards in 2002 (EI 2003) but work done at the Argonne Labs have helped lower production costs and should continue their advances in the next few years.

Acrylic acid can be used as an adhesive with nearly 907,029 tonnes produced yearly. Research is ongoing to find an economical process that would route lactic acid to acrylic acid. The target selling price is around $0.50 US per pound (EI 2003). The production of propylene glycol from lactic acid is also being examined to develop a conversion process that would enable more economical production of such chemicals as antifreeze, resins, and solvents. Propylene glycol could displace nearly 498,866 tonnes of competitive petroleum based standards yearly (Balkcom et al. 2002).

Pyruvic Acid can be derived from lactic acid as well. This small-volume chemical can be used in pharmaceuticals but has found a specialty market as a fungicide.

Succinic acid and its salts are formed naturally by plants, animals, and microorganisms but most of the commercial production in the United States has come from petroleum utilization. In recent years, nearly 13,605 tonnes of succinic acids and salts were produced per year (Brown 2003). The product can be used in a variety of fields from pharmaceutical products to clothing and solvents. Over the last decade, the Department of Energy has funded intense research to improve the bioproduction of succinic acid from bioorganisms in a more cost-efficient manner. Research advancement has reduced production costs from $2 US per pound in 1992 to nearly $0.50 US in 2002 (EI 2003). The domestic market is expected to grow as production costs decline; and the market is expected to be $1.3 US billion per year in the near future. These increases in productivity and switching to a bio-based platform from a petroleum platform will result in an energy savings of 2.87(e9) kWh per year when compared to current petroleum based pathways ( DOE 1999).

A wide array of products depend on succinic acid and its derivatives. Succinic salts are being introduced into herbicides to improve performance and effectiveness while also making the product safer to humans and the environment. The salts lower the freezing point of water, thus making it an excellent addition to coolants and an alternative to glycols. With the growing need to improve the performance of runway and wing deicing at state, federal, and military airports, succinic salts are being favored in light of stringent EPA regulations on current deicing chemicals due to environmental toxicity. Salts could replace 100 percent of the current market in the next few years. Airports use nearly 4,535 tonnes of deicers per year at a cost of $0.75 US per pound (EI 2003). Diversified Natural Products is the leader in succinic salt advances.

Tetrahydrofuran (THF) is a solvent derived from succinic acid. THF is a key ingredient in adhesives, printing inks, and magnetic tapes. In 2002, the US annual market for these uses was estimated at 115,646 tonnes and could potentially displace 22,676 tonnes or more at a selling point of $1.55 US per pound (EI 2003). BDO, or 1-4-Butanediol, is another succinic acid based compound that is used in solvents and coating resins. Bio-based BDO could displace 13,605 tonnes or more of the 308,390 tonnes that sold for $0.80 US per pound in 2002(EI 2003).

Succinate and disuccinate esters can be produced as well. Succinate esters are excellent fuel oxygenates and when used can result in a reduction of particulate emissions. Disuccinate ester is marketed as a green alternative to highly volatile or chlorinated solvents. Products in the personal care sector are also incorporating succinic acid into their mixture. Diversified Natural Products has produced a nail polish remover that is safe, biodegradable, and non-volatile so it lacks a "chemical" smell.

Acetic Acid

Acetic or Ethanoic acid is produced from lignocellulosic fermentation. It is currently manufactured mainly using the Monsanto process (Toreki 2003) where methanol from syngas reacts with carbon monoxide. In 1999, nearly 3,174,602 tonnes of acetic acid was produced in the United States and sold on average for $720 per ton (Brown 2003). It is used as a foodstuff, a solvent, and a fungicide as well as key in the production of pharmaceuticals like aspirin. Esters derived from the acid are used for the production of vinyl acetate used in paints, glues, and wallboard and cellulose acetate which is used mainly for rayon and photographic films. Vinegar is 4-8 percent acetic acid by volume. PET or polyethylene terephthalate, a thermoforming polymer commonly used for food and beverage containers, is also produced using acetic acid.

Fatty acids, readily available from plant oils, are used to make soaps, lubricants, and chemical intermediates such as esters, ethoxylates, and amides. These three important classes of intermediates are used in the manufacture of surfactants, cosmetics, alkyd resins, nylon-6, plasticizers, lubricants and greases, paper, and pharmaceuticals (Ahmed and Morris, 1994). Of the approximately 2, 267,573 tonnes of fatty acids produced in 1991, about  907,029 tonnes, or 40 percent, were derived from vegetable and natural oils. The remaining  1,360,544 tonnes were produced from petrochemical sources. Twenty-five percent of all plant-derived fatty acids used in the coatings industry comes from tall oil, a byproduct of kraft paper manufacture (Ahmed and Morris 1994).

Raw liquefaction oil is a free-flowing dark liquid produced through thermochemical liquefaction that can be stored and transported, thus allowing the decoupling of feedstock production, conversion process, and utilization. Comprised of oxygenated hydrocarbons and aromatic compounds, the various oil factions can be refined to produce oils with a heating value of approximately 36 MJ/kg or 4.54 kWh per pound with essentially no sulfur (BROKEN-LINK Duncan and White 2002).

Changing World Technologies has produced a light liquefaction oil that can be used as refined biodiesel known as TDP-40 through their Thermo Depolymerization Process. It can be used as a blended fuel or stand-alone to generate steam and power in a stationary diesel engine. With its refinement techniques, TDP-40 has shown improvements in combustion pollutant emissions reductions (BROKEN-LINK Duncan and White 2002).

Some factions of liquefaction oil can be used as solvents, such as Cyclohexane which is a paint remover and also used in making nylon. Methylethyl benzene is used in the production of rubber, waxes, and can be blended with gasoline as well. Toluene, alson derived from liquefaction oils, is used in the manufacturing of explosives and added to jet fuel to improve octane.

Pyrolytic bio-oil is a complex, combustible mixture of oxygenated hydrocarbons with chemical constituents that vary according to feedstock species. Whole bio-oil has a heating value of 2 to 2.2 kWh per pound; this heating value is roughly the same and may even increase after value-added chemicals have been extracted (BROKEN-LINK Sturzl 1997). To make the product as economical as possible, the Ensyn Group recommends extraction of secondary products prior to using the oil as fuel. Pyrolytic bio-oil fuel can be marketed as a free-flowing, dark brown liquid that can be stored and transported and thus gaining benefits associated with decoupling the feedstock source, chemical processing, and utilization.

Pyrolytic bio-oil has been used commercially for industrial heat since the early 1930s for firing boilers. It is currently being tested as a fuel for diesel transportation and stationary turbine and diesel power (BROKEN-LINK Diebold 2000). The wood industry relies on petroleum based phenol-formaldehyde resins in plywood, oriented strand board, and other wood composites. Resins from bio-oils could replace up to 50 percent of the phenol-formaldehyde. Ensyn is expecting to sell nearly 1.8 billion tonnes per year at $0.30 US a pound.

Red Arrow Food Products Company has taken bio-oil from fast pyrolysis processes and cornered the market on a niche product. Extracted additives from bio-oils can be used to infuse "smoked", "roasted", or "grilled" flavors in food.

Specialty chemicals play an integral role in the economy of the United States. Organic chemicals are primarily synthesized from a petroleum base and used for the production of paints, solvents, fibers, and plastics. These products allow the United States to maintain its lavish lifestyle. Increasing the feedstock for these chemicals or incorporating methods that allow industries to produce the needed organics from woody biomass can off-set the dependency on petroleum bases and the economic consequences that occur when supply is interrupted.

This is a selection of the various specialty chemicals that can be produced from using woody biomass:

• Ethylene
• Enzymes
• PDO
• 3-HP
• Bio-based Fuel gas and Syngas
• Butanol
• Glycerin

Ethylene

Ethylene is perhaps the most important petrochemical because of the value of its numerous derivatives such as polyethylene, ethylene dichloride, vinyl chloride, ethylene oxide, styrene, ethanol, vinyl acetate, and acetaldehyde (CLS 2000). Before lignocellulose conversion technology came on the horizon, the ethylene market was considered inaccessible to bio-based production (Lipinsky, 1981). Bio-based ethylene production based on ethanol derived from corn stover still is not cost competitive with petroethylene sources (Donaldson and Culbertson 1983). Ethylene based on lignocellulose fermentation could move into the margin of competitiveness against petrochemical sources when market price reaches $0.14 per pound; based on increasing cost projections for oil prices, using long-term projections developed by the World Bank (Gallagher and Johnson 1995). Ethylene can be produced in large-scale operations that already process ethanol, thus enabling manufacturers to manage the costs from sluggish marketing periods. With rising petroleum prices or further improvements in the bio-based ethylene production process, the cost advantage of petroethylene could erode.

Natural Essential Soap Co.

Glycerin is a sweet, viscous alcohol that is produced as a byproduct of the manufacturing of biodiesel. There are roughly 1 kg of glycerin for every 10 kg of biodiesel produced (De Guzman 2003). Selling for US$600 to US$900 per ton, glycerin is used in soaps, solvents, and industrial lubricants that perform on par with or better than petroleum-derived relatives (De Guzman 2003).

It is estimated that in 2006, 199,546 tonnes of glycerin will be utilized in the United States (De Guzman 2003). Natural Essential Soap Co. is just one of many small home-based soap and gylcerin-based companies. The market in the United States is currently for more "boutique" products, but glycerin is also used as a humectant, a food additive that has the effect of keeping foodstuff moist in packaging. Research questions do surround the potential of using anaerobic fermentation to produce methane from glycerin.

The primary source of current and future enzymes is the fermentation of biological materials (Ahmed 1993). Enzymes function as catalysts in industrial mechanisms to produce feed additives and chemicals as well as functioning as detergents, reagents, diagnostics, or health aids. In 1989, the worldwide sale of enzymes totaled US$650 million (Layman 1990) and topped US$1 billion by 1993 (Thayer 1994). Novo Nordisk currently supplies 40 - 50 percent of the worlds enzyme market, with other European companies controlling most of the remainder (Thayer 1994). Expectations are that enzyme sales will increase 10 percent annually until 2010 as new markets and needs emerge. In 1989, the market was divided into 40% detergent and soap, 25% starch conversion, and 15% dairy applications (Layman 1990). The remaining market included the leather, pulp and paper, and animal feed manufacturing sector needs. This remaining 20% is of particular interest due to the historical adverse environmental impacts that the industries have inflicted. The companies will have an incentive to use more benign processes such as those based on enzymes (CLS 2000).

Enzyme-derived products have replaced water-polluting phosphate detergents and allowed wash waters to be cooler, thus reducing energy consumption (Falch 1991). They are used to coagualte milk proteins for cheese production, as sweetners for sodas, and in lactose-free milk. Xylanase enzymes are starting to replace chlorine in the pulp and paper industry, cellulase in the textile industry, and protease has shown to reduce pollutants in leather manufacturing (Wrotonowski 1997).

Carpet from PDO

A lignocellulosic fermentation product, PDO is most commonly combined with terephthalic acid to produce polytrimethylene terephthalate (PTT). PTT is a high performance polyester polymer that is used in carpets, upholstery, and apparel for its softness, dyeability, ease of care, and remarkable stretch-recovery. Currently it is almost exclusively manufactured from petrochemical feedstocks by Shell Chemical and DuPont.

Although PTT has been used by companies for over 50 years, only recently has it been discovered as a possible product from biomass. DuPont has announced that it plans to construct a large-scale PDO fermentation plant in 2006 and produce PTT using non-petrochemical inputs.

In 2002, the size of the PTT market was 454 million tonnes per year and sold at US$0.25 per ton (EI 2003). Tests have shown that the durability and strength of bio-based PTT surpasses nylon and PET in fiber applications and such resin applications as sealable closures, connectors, and blister packaging (Hwo and Shiffler 2000).

Nitrile Rubber Rings from 3-HP

3-HP is the best known intermediate chemical produced by lignocellulosic fermentation behind lactic acid and succinic acid. Produced by Cargill, research has shown that the intermediate chemical can be produced at a theoretical yield of 100 percent from glucose (Zvosec 2003). With the addition of chemical processing, 3-HP can be transformed into many various marketable chemicals such as PDO, acrylic acid, acrylonitrile, and acrylamide. There is no commecially viable production route of 3-HP from fossil fuel feedstocks (EI 2003). Cargill is currently collaborating with the Pacific Northwest National Laboratory and the US Department of Energy on a $12 US million research project to investigate improved commercialization of the product.

When transformed into acrylic acid, the polymer can be used as a coating, adhesives, superabsorbent, or detergent. The 2002, market demand was 907,029 tonnes and sold for $0.48 US per pound (EI 2003). Acrylonitrile is a polymer found in the acrylic fibers of carpets and clothing, pipes, furniture, automobiles, and nitrile rubber. It sold for $0.35 US per pound in 2002 and 1.4 million tonnes are produced yearly (EI 2003). Acrylamide is a resin used in latex. In 2002, the market for acrylamide was 93,424 tonnes drew US$1.80 per pound (EI 2003).

Syngas Plant in Maryland

Fuel gas and syngas are products of either black liquor gasification or biomass gasification. The mixture of raw product gases vary according to the feedstock and the gasification approach utilized. Regardless of the process, fuel gas and syngas must be separated from mineral ash and char, alkali compounds, tars, nitrogen components, and sulfur (Stevens 2001). For use in fuel synthesis or fuel cells, the gases must also be reduced to remove methane, ethane, and other hydrocarbons.

Bio-based fuel gas is also known as producer gas or wood gas and contains a relatively low energy density. Over 50 percent of its content is nitrogen and 40 percent hydrogen and carbon monoxide. This produces a heating value of about 5 MJ/m3 in a biomass gasification process. Bio-based syngas is a medium energy mixture that is richer in hydrogen and carbon monoxide with a heating value of 10 to 20 MJ/m3 (Ross 1996).

Low energy fuel gas is most suitable for combustion to produce thermal energy, however research by FlexEnergy is examining its potential for combustion in microturbines. Medium energy syngas, once cleaned, can be used as fuel in boilers or to fuel electricity and steam generation via gas turbines or fuel cells. However, some fuel cell designs should not be used due to the limited tolerances for carbon monoxide. Steam reformed syngas has a high content of hydrogen and is used in applications that demand high levels of gas cleanliness. Methanol and DME or dimethylether are liquid fuels that can be used in automotive systems. They have a hydrogen to carbon monoxide ratio of 2.1 to 1 and, with the Fischer-Tropsch process, utilize metal catalysts to widen the range of hydrocarbons that can be produced. At the present time this process is not yet competitive with coal or petroleum but as prices continue to climb for those fossil fuels, F-T plants are becoming more of an option (Rauch 2002).

The fuel gas is fed to microorganisms that can convert the gas to ethanol, methane, or other fuel forms. Research is ongoing to look at the effectiveness of producing bio-based feedstocks for plastics, wax oils, methane, and ethanol from these organisms (Larson et al. 2003, Paisley and Overend 2002).

CXI/Texmark R&D

Butanol is an organic chemical that can be broken down into several large-volume derivatives. It has been suggested that butanol can be used as a biobased oxygenated fuel for blending in gasoline. Butanol has several advantages over methanol and ethanol, such as having an energy content closer to that of gasoline with few to no mechanical and chemical compatibility issues (Brown 2003). In 1999, 839,002 tonnes of butanol was used domestically and it is projected that the usage will increase 3 percent per year, expanding demand significantly when blended with gasoline (EI 2003).

Unlike ethanol, butanols boiling point is significantly higher than water and can only be recovered after the still water has evaporated. Butanol is also more toxic than ethanol with production levels at concentrations no higher than 2.6 percent compared to the 12 percent in ethanol production. The production of butanol using glucose fermentation is costly with low yields and has been replaced by petrochemical routes (Ramsey et al. 2002). However, the U.S. Department of Energy is funding research through the Small Business Innovation Research program to improve the bio-based route to butyric acid and butanol with the intent to make it cost-competitve with the petroleum based pathways.

Beyond its use as a potential transportation fuel and blend, butanol and its derivatives are being used in plasticizers, resins, and amines. It is used as a solvent in lacquers, thinners, inks, disinfectants, and fungicides. Butyl butyrate is being investigated as a food flavoring, providing a fruity taste. Butanol and its derivative products sold for US$0.55 per pound in 2002 (EI 2003).

Hydrocarbon feedstocks have dominated as industrial inputs over the past century, but as petroleum reserves decline, renewable biomass feedstocks are being asked to meet the global consumer need. Wood waste streams can be reprocessed into many durable building materials. Opportunities exist to replace non-sustainable, valuable feedstock with a sustainable, low-value waste stream in nearly every category of building materials. Increased consumer demand for environmentally benign products are resulting in numerous opportunities for bio-based materials in the marketplace (Narayan 1994).

The following is a partial list of bio-based materials that are currently on the market. As university and industry directed research and development continues, we discover new and amazing substitutes for traditional petroleum based products at a rapid rate.

• Pellets
• Char
• Glass Aggregate
• PHA Polymers
• Anaerobic Digestion Effluent
• Bioplastics
• Biopolymers

Renewable resources such as industrial starches, fatty acids, and vegetable oils can serve as sources for bioplastics. Biodegradable thermoplastics—such as starch esters, cellulose acetate blends, polylactide, and thermoplastic proteins - such as zein, and polyhydroxybutyric acid (PHB)—show great promise for replacing the plastics derived from petrochemicals that generally are not biodegradable (Kaeb 2005). Graft plastic polymers, or plastics based on plant materials and petrochemicals, are less bio-degradable than plant-based bioplastics. In 1994, bioplastics comprised about 5 percent of the total polymer, plastics, and resin market (Ahmed and Morris, 1994).

The bioplastics industry has generated new markets for industrial starches. Starch can be directly manufactured into products such as biodegradable loose-fill packaging to replace nondegradable polystyrene-based packaging filler. Fermenting starch into lactic acid, or PHB, yields other starch-derived thermoplastics. The Cargill Company has introduced polylactide-based thermoplastics for single-use disposable products such as utensils, plates, and cups. ICI Corporation has commercialized biodegradable PHB plastics for shampoo bottles and other higher-cost disposables. Plant matter also provides a new material for direct processing into plastic and polymeric resins.

A graft polymer of latex and starch is used to make coated papers. Certain starch-based plastics are also in commercial use, as are various graft polymers between starch and synthetics. One class of graft polymers absorb many times its weight in water and has many applications such as absorbent soft goods such as absorbents for body fluids, disposable diapers, hospital underpads, and related products, hydrogels, and agricultural products such as seed and bare root coatings and hydromulch (Doane et al., 1992). These hydrophilic graft polymers are prepared using polyacrylonitrile in which the nitrile compounds have been hydrolyzed with alkali. Many new starch-based polymers and applications are expected to appear soon in commercial uses.

In 2003, the nations of the European Union consumed 36,281 tonnes of bioplastics according to the International Biodegradable Polymers Association and Working Group. In 2002 nearly 217,687 tonnes of bioplastics were consumed worldwide and the estimate for 2008 exceedes 542,217 tonnes worldwide (Kaeb 2005). The European Union has a process for certifying and labeling bioplastics. This has helped European grocery stores such as Tesco and Sainsbury attract the environmentally conscious shopper by providing not only organic foods but organic packaging as well. The Sony Corporation is now using bioplastics in the construction of their new MP3 players. In anticipation of  large amounts of waste, the Olympic games in Bejing China has dedicated itself to using only bioplastics for all of its packaging, increasing the Asian market influence on bioplastic development.

The great majority of all biomass consists of polysaccharides. These natural biopolymers can be used both in their original form after extraction from plants or as the skeletal framework of other derived polymers. By far the most abundant of these carbohydrate polymers is cellulose, the principal component of cell walls of all higher plants. It is estimated that  68 billion tonnes of cellulose are biosynthesized and become lost for utilization year through natural decay (BCST 2005).

While use of biopolymers is now considerable, the current use represents only a small fraction of the total market potential, as measured by biopolymer plus petroleum-based polymer demand. The substitutional potential is enormous for the future. Broader application of such preformed polymeric materials awaits research and development (BCST 2005).

Cellulosic plant materials are used as fuel, lumber, and textiles. Cellulose is currently used to make paper, cellophane, photographic film, membranes, explosives, textile fibers, water-soluble gums, and organic-solvent-soluble polymers used in lacquers and varnishes.

The principal cellulose derivative is cellulose acetate, which is used to make photographic film, acetate rayon, various thermoplastic products, and lacquers. The worlds annual consumption of cellulose acetate in 1999 was 680,271 tonnes, with 362,812 tonnes being produced in North America (CLS 2000). Cellulose acetate products are biodegradable.

Courtaulds, a company from the United Kingdom recently purchased by Sara Lee, and the Austrian firm Lenzing, each have begun large-scale production of lyocell, a cellulosic fiber made from a solvent spinning process and sold under the trade name of Tencel. Like rayon, Tencel is wood-pulp based; however, rayon requires dry cleaning and Tencel is washable. Tencel is the first new textile fiber to be introduced in 30 years and has been described as the "best thing since cotton."

Char is the soild portion of biomass that does not fully react during pyrolysis, combustion, or thermochemical liquefaction. Its composition and applicability are functions of the original feedstock and the biorefining process used. One of the most common uses of char is to recycle it through reintroduction to kilns and boiler combustion systems to produce steam for heat and energy (Kumar and Gupta 1998).

Char is also an excellent filtration agent. Activated carbon is heavily used in both liquid and gas filtration. Converting char to activated carbon can be performed relatively easy with steam or acid. The process alters the porosity of the carbon, changing the available surface area making it an excellent filtering agent. Roughly 165,533 tonnes of activated carbon is sold annually (EI 2003).

Research and product development is ongoing. Eprida is investigating the use of char as a base for high nutrient fertilizers that return carbon to the soil. DynaMotive was one of the first companies to work with char as activated carbon and is looking into converting the product into charcoal briquettes. Both companies have been successful in small test studies.

Internal View of Cyclone Melter

Glass aggregates are amorphous solids that are formed by the melting of minerals from various sludge effluents, most commonly from paper mill residues. The aggregates are ground into various sizes depending on potential use; including asphalt paving, pozzolanic material for cement, sandblasting media, shingle granules, or ceramic tiles. Minergy is the worlds largest producer of glass aggregates and sells their products anywhere from $0.50 to $40 per ton of material (2005). Recently, the companys vitrification process passed the American Society for Testing and Materials water leachate tests, proving that the process truely does meet the standards of binding harmful metals from the effluent inside the material.

PHA to PBO

PHA polymers are just one of the many products that result from lignocellulosic fermentation. It is a polyester with highly promising thermoplastic polymer applications. Research has shown that PHA may outperform PLA (Polylactic Acid) with regards to tensile strength and modulus of elasticity (Westmoreland 1999). Both PHA and PLA are considered excellent bio-based product substitutions for PET (Polyethylene terephthalate) which is used for everything from soda bottles to electronics casing ( Balkcom et al. 2002). If economically produced, PHA could capture a significant portion of the plastics market. PHVB is a PHA polymer which has been utilized in the commercial production of plastic bottles and coated paper. Recently, PHA has been examined by the transportation industry for use; labeling it a smart material. PHA, when exposed to heat will break down slightly before decomposing into polybenzoxazole or PBO (Balkcom et al. 2002). PBO is virtually unformable, making it a terrible material to mold into chairs or liners, but it is extremely fire resistant. The use of PHA in airliners, trains, and buses would drastically improve safety efforts of the transportation industry (Westmoreland 1999). Industry and university research has discovered that PHA polymers are naturally produced by some bacteria and work is underway to determine if they can be grown inside genetically modified plants (Harper 2000).

The market size for PHA polymers in 2002 was 13, 605,435 tonnes at a selling price range of $0.30 - $1.50 per pound (EI 2003).

Pellets

In order to increase the density, and thus allow easier handling and storage, biomass in the form of small particles such as straw, sawdust and chips can be processed and converted into briquettes or pellets. Depending on the equipment used for densifying the material and the types of biomass, their basic density can vary from 600 kg/m3 to 1500 kg/m3 (Zerbe 2004). The moisture content of the biomass to be compacted usually needs to be between 7% and 14%, since if it is higher it will not compact easily, and if lower the compacted product will not bind as well (Zerbe 2004).

In the case of wood pellets, a biomass fuel with a good potential for market penetration, one of the main advantages compared to other commonly used biomass fuels, such as wood chips and logs, is their convenience. Bags of pellets stack compactly, store easily, and their uniform and small shape allows them to flow making the automation of fuel handling easy (Lehtikangas 2000). The small size of pellets also allows for precisely regulated fuel feeding and combustion air can be regulated easily for optimum burn efficiency. High combustion efficiency is also due to the uniformly low moisture content of pellets, typically 7-8%, compared to 30-35% moisture content in wood chips, and leads to a high heat output and a very low level of unwanted emissions (Pier and Kelly 1997).

The PROPELLETS project is a global strategic initiative that began January 1, 2005 with the aim of promoting pellet heating systems.

PROPELLETS Material

PROPELLETS is a joint European organizational initiative to promote pellet heating systems in the European Marketplace. Through demonstrations of the technical-economic feasibility of pilot heating facilities, targeted awareness and educational programs, and market structure analysis and promotal activities to overcome barriers, PROPELLETS is seeking to stimulate biomass usage for the purpose of energy and heat.

The project began on January 1, 2005 and is scheduled to conclude December 31, 2007. It is expected that a new total installed capacity of 5 MW will be created during the process. This production will be achieved by locating 25 pilot facilities with a 200 kW capacity each. If successful, these pilot plants will be using woody biomass to substitue 30,839 tonnes/year of coal and will avoid the emission of 12,698 tonnes of carbon dioxide per year.

Visit the PROPELLETS homepage or any of the four project participants for more information and project updates.

Project Participants

• Renewable Heat & Power LTD, United Kingdom
• Jyvaskyla Science Park, Finland
• Energia Transporti Agricoltura Srl, Italy
• O.O. Energiesparverband, Austria