Biomass (Renewable) Resources for Production of Materials

Chapter 1

Biomass (Renewable) Resources for Production of Materials, Chemicals, and Fuels A P a r a d i g m Shift Ramani Narayan

Downloaded by 187.246.18.28 on September 26, 2015 | http://pubs.acs.org Publication Date: December 4, 1992 | doi: 10.1021/bk-1992-0476.ch001

Michigan Biotechnology Institute and Michigan State University, Lansing, M I 48909

There is a resurgence of interest in abundant, renewable, biomass resources as precursors for the production of polymeric materials, organic chemicals, and fuel. This heightened awareness and sense of urgency toward biomass utilization is driven by 1) environmental concerns, and the need for environmentally compatible polymers and chemicals. 2) the need to be weaned away from our dependance on non renewable imported petroleum feedstocks, and 3) utilization of the nation's abundant, renewable agricultural feedstocks in new non-food, non-feed uses.

Industry has always been driven by three paramount factors in the development of products and processes. They are: • Productivity • Efficiency and Functionality • Economics To meet these criteria for production of polymeric materials, organic chemicals and fuel we have come to rely heavily on a single non-renewable resource, namely oil, to the total exclusion of other resources. Other factors, namely: • sustainability of oil resources and dependance on foreign imports, • the impact on the environment, both before and after use (waste management), • the folly of depending on only one resource for all our needs, have not been taken in to consideration during the development of a product or process. The need and importance of taking these additional factors in to consideration has been the subject of frequent debates as during the energy crisis of the 70's and more recently during the Persian Gulf crisis. However, as normalcy returns, the questions are swept aside and we go back to business as usual. This has resulted in an increasing dépendance on foreign oil and, therefore, more vulnerable to supply disruptions and price manipulation. Our oil imports have risen sharply since 0097-6156/92/0476-0001$06.00/0 © 1992 American Chemical Society

In Emerging Technologies for Materials and Chemicals from Biomass; Rowell, R., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1992.

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MATERIALS AND CHEMICALS FROM BIOMASS

the 80's, and U.S. dependence on foreign oil is close to the 50% mark - half from a politically unstable region (Figure 1).


As Daniel Yergin says in his recent book about oil "The Price" (Simon and Schuster, 1991), "Petroleum remains the motive force of the industrial society and the life- blood of civilization that it helped create. It also remains an essential element in national power, a major factor in world economics, a critical focus for war and conflict, and a decisive force in international affairs." Today, with a victorious Persian Gulf war behind us and oil being pumped out of the Persian Gulf as never before - 2.2 million barrels a day (1), the continued use of oil as the feedstock for polymeric materials, organic chemicals and fuel seems even more enshrined. The Paradigm Shift In spite of the above seeming complacency about oil as the primary feedstock, there is a climate of change in industry. The driver for this change is the growing concerns about the environment. Therefore, industry is being asked to reevaluate its priority relative to productivity, efficiency and economics and add three more factors to the equation. These are: • Resource conservation - the utilization of renewable resources as opposed to non-renewable oil resources; and more importantly, • The effect of processes and products on the global environment compatibility of products and processes with the environment; • Waste management - disposal of waste in an environmental and ecologically sound manner - issues of recyclability and biodegradability. The key word is "Environmentalism," and environmentalism will be the biggest business and industry issue of the 90's and beyond. This "greening" of the industry resulted in key international companies and industrial organizations meeting in Rotterdam to endorse a set of principles and a charter that will commit them to environmental protection into the 21st century (2). One hundred and fifty companies including some major U.S. chemical concerns and more than thirty-five organizations adopted the business charter for sustainable development. In support of this document 16 principles developed by the Paris-based International Chamber of Commerce (ICC) were adopted. According to ICC the principles are designed to place environmental management high on corporate agendas and to encourage policies and practices for carrying out operations in environmentally sound ways. The U.S. affiliate of ICC, the U.S. Council for International Business, sees the principles "as the culmination of building American corporate awareness of the importance of sustainable development." Some of the key principles of the charter are: • Develop and operate facilities and undertake activities with energy efficiency, sustainable use of renewable resources and waste generation in mind • Conduct or support research on the impact and ways to minimize the impacts of raw materials, products or processes, emissions and wastes


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• Modify manufacturing, marketing, or use of products and services to prevent serious or irreversible environmental damage; develop and provide products and services that do not harm the environment • Contribute to the transfer of environmentally sound technology and management methods. Biomass derived renewable polymer resources can play a major role under this new environmental climate. Clearly, the processes, products and technologies adopted and developed using renewable resources must be compatible with the environment. Furthermore, the wastes generated should be recycled or transformed into environmentally benign products. Youngquist and co-workers, in Section 2 of the book, describe work on lignocellulosic plastic composites made from recycled plastics. The idea ties in biomass renewable resource utilization with recycling of the post- consumer plastic waste - a major waste management issue. Thus, the twin issues of environmental responsibility and resource conservation (moving away from non-renewable oil feedstocks) has led to a resurgence of interest in renewable biomass resources as the precursor for polymeric materials, organic chemicals and fuels. The chapters in the book present an overview of the emerging technologies, products and processes that are capitalizing on this renewed interest and enthusiasm for biomass derived polymeric materials and chemicals (Figure 2). One of the major questions raised about biomass utilization is its effect on global warming. The consumption of biomass resources would mean that there will be less biomass available to fix CO2 emmissions. There is also the question of CO2 released in the atmosphere during combustion or in other waste disposal schemes such as composting. These are important points, since environmental considerations are the driver for the present change. However, by producing biomass at a sustainable rate (continuous replenishment of biomass utilized with new growth), the CO2 consumed during photosynthesis should balance the amount of CO2 released in processing biomass. Thus, biomass utilization would make no net contribution to the CO2 in the atmosphere, and so it would have negligible impact on global warming. Figure 3 illustrate these concepts and shows some of the energy and profits from the biomass utilization cycle being ploughed back into replantation of biomass. Thus, biomass resources, if properly managed, can contribute to a sustainable resource and environment base. However, one must, also, carefully address other environmental consequences of biomass utilization including air pollution, residues, ash, and depletion of cell nutrients to make biomass a acceptable feedstock. These must, therefore, be studied carefully and appropriate standards and regulations developed. Life cycle or Cradle to Grave analysis must be performed on the emerging biomass technologies. This analysis is a holistic environmental and energy audit (accounting procedure) that focuses on the entire life cycle of a product, from raw material production to final product disposition, rather than a single manufacturing step or environmental emission.


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Figure 2.

Emerging materials, chemicals, and fuels from biomass.


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Biomass Resources for Afateriak, Chemicak, and Fueb

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Chum and Power's chapter on Opportunities for the Cost Effective Production Biobased Materials" and "The Potential and Pitfalls of Biomass & Wastes"; Grohaman and coworkers chapter on "Potential for fuels from Biomass and Wastes"; Barrier and Bull's chapter on "Feedstock Availability of Biomass & Wastes, and Goldsteins chapter provides details on these issues. The avaialability of biomass feedstocks, and the potential economic impact of biomass utilization is discussed later in this chapter. U.S. national policy seems moving in the direction of producing industrial materials from biomass resources. The provisions of the 1990 Farm Bill (Food Agricultural, Conservation and Trade Act of 1990 , X V I Subtitle G ) is to expedite the development and market penetration of industrial products that use agricultural materials. The act also provides for R & D and commercialization assistance. The U.S. Department of Agriculture (USDA) through the Agriculture Research Service (ARS) has R & D programs to produce new industrial products from agricultural raw materials. Doane and coworkers review some of this work in their chapter. The U S D A Forest Products Research Service is looking at utilizing lignocellulosic biomass resources to produce new composite materials and other industrial products (see Section 2). The Department of Energy through their Advanced Industrial Materials Program in the Office of Conservation and Renewable Energies have a small R & D program on new industrial products from renewable resources (see Chum's chapters in this book). Biomass Derived Materials Biomass derived materials are being produced at substantial levels. For example, paper and paperboard production is around 139 billion lbs, and biomass derived textiles production around 1.2 million tons (see Chum's chapter). However, biomass use in production of plastics, coatings, resins and composites is negligible. These areas are dominated by synthetics derived from oil and represent the industrial materials of today. Lignocellulosics-Composites. Wood is the oldest known composite material -flexible cellulosic fibers assembled in an amorphous matrix of lignin and hemicellulosic polymer. It continues to find extensive use in the construction industry. A lignocellulosic composite such as particleboard and fiberboard are lignocellulosic fibers embedded in a thermoplastic or thermoset matrix. Lignocellulosic materials such as wood flour are used as inexpensive filler in phenolic resins and thermoplastics. However, the cost, availability, renewability, and recyclability of lignocellulosics offer the potential to expand their market use into the large volume, low-cost, high performance structural composites - the automobile and durable goods market (Figure 4) (3, 4). Section 2 of the book is devoted to this area, and presents emerging technologies that can provide biomass derived low-cost high performance materials that competes with the totally synthetic materials. Rowell's chapter showcases in detail the opportunities and requirements for lignocellulosic materials and composites. Youngquist deals with the effective utilization of recycled plastics by combination with lignocellulosics. The



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Figure 3.

Impact of biomass utilization on global warming.

PRODUCTION VOLUME — pounds Figure 4. Major markets for structural composites. (Reproduced from réf. 4. Copyright 1988 American Chemical Society.)


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compatibilization of lignocellulosics with synthetic polymers to provide new thermoplastic alloys with improved functionality and properties is discussed by Narayan. The properties of such new composite materials is discussed in chapters by Raj & Kokta, and Plackett. The ability to turn lignocellulosics into thermoplastics with the desired properties and ease of processing is described by Matsuda. The new world of lignocellulosic liquefaction is introduced by Shiriashi. Biopolymers and Derivatives. The production of only five of the leading thermoplastics (low and high density polyethylene, polystyrene, polypropylene, and polyvinyl chloride) totalled 48 billion pounds in 1990. The replacement of these synthetic polymers in part or full would create new large volume markets for biomass polymers. Cellulosic derivatives (Chapters by Hon, and Majewics & Sau), starch and modified starches (Doanne and co-workers), soy protein polymers (Krinski), monomers and polymers based on oligosaccharides (Dirlikov), lignin polymers (Northey) are potential contenders for the markets dominated by the synthetic polymers. Thermoplastics made from synthetic oil are today formulated to be strong, light weight, durable and bioresistant. They are resistant to biological degradation in the environment because the natural microbial population does not have polymer specific enzymes capable of degrading and using most man-made synthetic polymers. In addition, the hydrophobic character of most synthetic plastics inhibits natural enzymatic activities and the low surface area of the plastic with the inherent high molecular rates compounds the problem further. It is this durability, light weight and indestructibility that makes these plastics materials of choice for many packaging and consumer goods applications but also creates problems when they enter the waste streams. Plastic litter and errant medical waste scar landscape, foul our beaches, and pose a serious hazard to marine life. Nationwide, between 40-60% of beach debris is plastic. A n additional 10-20% is expanded polystyrene foam (5). It has been estimated that 50-80% of materials washing ashore will remain undegraded in the environment, i.e., they are persistent and recalcitrant, and not readily broken down by the elements to become a part of the natural carbon cycle of the ecosystem (6, 7). As a result there are mounting concerns over the disposal of persistent disposable and non-degradable plastics that are often and perhaps not always fairly singled out as the major culprit (8). This leads us to the concept of designing and engineering new biodegradable polymeric materials, materials that are plastics, i.e. strong, light weight, easily processable, energy efficient, excellent barrier properties, disposable (mainly for reasons of hygiene and public health) yet break down under appropriate environmental conditions just like its organic (lignocellulose) counterpart. It also includes developing new concepts and technologies for handling our waste, and also creating waste disposal infrastructures in tune with the natural carbon cycle. The rationale for biodegradable polymers and its role in waste management has been discussed in detail by Narayan (4,5).



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Thus, new market opportunities for biopolymers and derivatives, such as described in section 3 of the book, presents itself in areas such as single use, disposal, short life packaging materials, service ware items and disposal non-wovens. A n estimated 30% of synthetic polymers from non-renewable oil feedstocks totalling 16.5 billion pounds annually are used in these applications. Marine plastics is another category that lends itself to utilization of biodegradable material concepts. These include fishing gear such as drift net traps and packaging materials such as plastic sheets, strapping, shrinkwrap, polystyrene foam products and domestic trash such as plastic bags, bottles and beverage ring containers. Indeed, major corporations such as Warner-Lambert (Novon product line), National Starch and Chemical, Archer Daniels & Midland (ADM), and more recently the Ecological Chemical Products Company (ECOCHEM - a joint venture of DuPont and ConAgra) have announced production of polymeric materials derived from renewable biomass resources solely with such an environmental theme. Biofuels and Chemicals As the only renewable technology to produce liquid transportation fuels, biofuels have the potential to displace the crude oil being imported today. In doing so, it could reduce the environmental problems because they consume as much carbon dioxide (a greenhouse gas) in their growth and production as they release in their use. They also produce few, if any, sulfur compounds. This is an important factor in a world that is learning about the greenhouse effect and becoming concerned about the diminishing quality of the environment. Because biofuel conversion processes produce little ash and few if any sulfur compounds, biofuels contribute to an improved environment In using municipal waste to produce energy, biofuels technology is helping to solve a growing environmental problem, it also reduces the need for landfills by using industrial and municipal wastes. The U.S. Department of Energy (DOE) Biofuels Municipal Waste Technology (BMWT) program focuses on five pathways for biofuel production. Their combined energy potential is estimated at approximately 17 quads or 20% of current U.S. energy consumption. Approximately 3 quads (3-5%) are currently generated from wood and waste alone representing roughly the same contribution made by nuclear energy (4-5%) or hydropower (4%). More than eighty facilities nationwide burn municipal solid wastes (MSW) and refuse derived fuel (RDF) to provide heat for industrial processes and for electricity generation. Meanwhile, starch and sugar crops are being converted to 850 M M gallons of fuel ethanol each year for use in gasoline blends where it raises the octane rating and reduces carbon monoxide emissions. K . Grohmann and co-workers and Barrier and Bulls review this very important biofuels area in Section 4 of this book. While the primary thrust of this book is on production of polymeric materials, composites and chemicals from lignocellulosics and its polymer constituents primarily cellulose and lignin, other biomass resources such as starches, oilseeds, industrial crops such as guayule, soybean and many more can also serve as feedstocks. Some of these have been covered in the book - polymeric materials from starches, rubber and other materials from guayule, materials based on soy


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protein, plants as sources for drugs and chemicals. Some have not been covered, again testifying to the versatility and flexibility of biomass resources. Of these mention must be made of the preparation of nylons ~ nylon 9, and nylon 13, 13 from the erucic acid of crambe or industrial rapeseed oil (9), the use of soybean oil for petrochemical resins in printing inks, and vernonia oil, a natural epoxidized vegetable oil, as a replacement for conventional solvents in alkyd and epoxy coatings (10). Vegetable oils are used in lubricants, and industrial rapeseed oil is used as a supplement in automatic tramsmission fluid.


Biomass Feedstocks The abundance of renewable biomass resources can be illustrated from the fact that the primary production of biomass estimated in energy equivalents is 6.9 χ 1 0 ^ kcal/year(ll). Mankind utilizes only 7% of this amount, i.e 4.7 χ Ι Ο ^ kcal/year, testifying to the abundance of biomass resources. In terms of mass units the net photosynthetic productivity of the biosphere is estimated to be 155 billion tons/year (12) or over 30 tons per capita and this is the case under the current conditions of non-intensive cultivation of biomass. Forests and crop lands contribute 42 and 6%, respectively, of that 155 billion tons/year. The world's plant biomass is about 2 χ 1

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1012 tons and the renewable resources amount to about 1 0 tons/year of carbon of which starch provided by grains exceeds 109 tons (half which comes from wheat and rice) and sucrose accounts for about 108 tons. Another estimate of the net productivity of the dry biomass gives 172 billion tons/year of which 117.5 and 55 billion tons/year are obtained from terrestrial and aquatic sources, respectively (13). It is estimated that U.S. agriculture accounts directly and indirectly for about 20% of theGNP by contributing $ 750 billion to the economy through the production of foods and fiber, the manufacture of farm equipment, the transportation of agricultural products, etc. It is also interesting that while agricultural products contribute to our economy with $ 40 billion of exports, and each billion of export dollars creates 31, 600 jobs (12) (1982 figures), foreign oil imports drains our economy and makes up 23% of the U.S. trade deficit (U.S. Department of Commerce 1987 estimate) Forests cover one third of the land in the 48 contiguous states (759 M M acres) and commercial forests make up about 500 M M acres. Fortunately, we are growing trees faster than they are being consumed, although sometimes the quality of the harvested trees is superior to those being planted. Agriculture uses about 360 M M acres of the 48 contiguous states, and this acreage does not include idle crop lands and pastures. These figures clearly illustrate the potential for biomass utilization in the U.S. Conclusions The conversion of biomass resources to polymeric materials, chemicals and fuels can:



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• Spur new sustainable industrial development with energy efficiencies and economies • Mitigate environmental concerns and provide for a sustainable environment • Reduce our dépendance on foreign oil imports and the drain on our economy • Contribute to the growth and development of our economy The absurd situation of the U.S. government artificially limiting the agricultural production capabilities of this country will and can be eliminated, if utilization of renewable biomass resources toward addressing the problems of stable resource base and ecologically sound waste management practices be adopted. Rather than subsidies and PIK (pay in kind) program that compensates farmers for a reduction in cultivated land (by giving them credit with crops held in government storage) we should be using our biomass potential as a feedstock for materials, chemicals and fuel besides food. The time is right for a greater national commitment toward biobased materials, and chemicals. New emerging technologies that are showcased in this book have created products and processes that are competitive with oil based synthetics, and contribute to a sustainable environment. A recent Chemical & Engineering News article (14) chronicles very nicely this push for new materials and chemicals from biomass.

Literature Cited 1. News Item C& E News, July 17, 1991, pp. 20. 2. News Item, C & Ε News, April 8, 1991, pp 4. 3. Chum, H . L.,In Assessment of Biobased Materials, Solar Energy Research Institute (SERI), Report No. SERI/TR-234-3610, 1989. 4. Fishman, N . , "Abstracts of Papers", 196th National Meeting of the American Chemical Society, Los Angeles, Calif., Sept. 1988, C M E 1. 5. Alaska Sea Grant Rep[ort No. 88-7 on "Workshop on Fisheries, Generated Marine Debris and Derelict Fishing Gear" February 9-11, 1988. 6. Narayan, R., Kunstoffe, 1989, 79 (10), 1022. 7. Narayan, R., INDA Nonwoven Res., 1991, 3, 1. 8. News Item, Modern Plastics, Waste Solutions, April, 1990. 9. Van Dyne, D. L., and Blase, G. M . , Biotechnol Prog., 1990, 6, 273. 10. Dirlikov, S., ACS Symp Ser., 1990, 433, 176. 11. Primary Productivity of the Biosphere, Lieth, H., and Whittaker, H . R., Eds., Springer Verlag, 1975. 12. Institute of Gas Technology, Symposium on "Clean Fuels from Biomass and Wastes", Orlando, Florida, 1977. 13. Szmant, Η. H., Industrial Utilization of Renewable Resources, Technomic Publishing Co., Lancaster, Basel, 1986. 14. Borman, S., C & Ε News, September 10, 1990, pp 19. RECEIVED July 29, 1991


Biomass (Renewable) Resources for Production of Materials

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