Renewable resources, their use and modification are involved in a multitude of important processes with a major influence on our everyday lives. Applications can be found in the energy sector, chemistry, pharmacy, the textile industry, paints and coatings, to name but a few.

The area interconnects several scientific disciplines (agriculture, biochemistry, chemistry, technology, environmental sciences, forestry…), which makes it very difficult to have an expert view on the complicated interaction. Therefore, the idea to create a series of scientific books, focusing on specific topics concerning renewable resources, has been very opportune and can help to clarify some of the underlying connections in this area.

In a very fast changing world, trends are not only characteristic for fashion and political standpoints; also, science is not free from hypes and buzzwords. The use of renewable resources is again more important nowadays; however, it is not part of a hype or a fashion. As the lively discussions among scientists continue about how many years we will still be able to use fossil fuels — opinions ranging from 50 years to 500 years — they do agree that the reserve is limited and that it is essential not only to search for new energy carriers but also for new material sources.

In this respect, renewable resources are a crucial area in the search for alternatives for fossil-based raw materials and energy. In the field of energy supply, biomass and renewable — based resources will be part of the solution alongside other alternatives such as solar energy, wind energy, hydraulic power, hydrogen technology and nuclear energy.

In the field of material sciences, the impact of renewable resources will probably be even bigger. Integral utilization of crops and the use of waste streams in certain industries will grow in importance, leading to a more sustainable way of producing materials.

Although our society was much more (almost exclusively) based on renewable resources centuries ago, this disappeared in the Western world in the nineteenth century. Now it is time to focus again on this field of research. However, it should not mean a ‘retour a la nature’, but it should be a multidisciplinary effort on a highly technological level to perform research towards new opportunities, to develop new crops and products from renewable resources. This will be essential to guarantee a level of comfort for a growing number of people living on our planet. It is ‘the’ challenge for the coming generations of scientists to develop more sustainable ways to create prosperity and to fight poverty and hunger in the world. A global approach is certainly favoured.

This challenge can only be dealt with if scientists are attracted to this area and are recognized for their efforts in this interdisciplinary field. It is, therefore, also essential that consumers recognize the fate of renewable resources in a number of products.

Furthermore, scientists do need to communicate and discuss the relevance of their work. The use and modification of renewable resources may not follow the path of the genetic engineering concept in view of consumer acceptance in Europe. Related to this aspect, the series will certainly help to increase the visibility of the importance of renewable resources.

Being convinced of the value of the renewables approach for the industrial world, as well as for developing countries, I was myself delighted to collaborate on this series of books focusing on different aspects of renewable resources. I hope that readers become aware of the complexity, the interaction and interconnections, and the challenges of this field and that they will help to communicate on the importance of renewable resources.

I certainly want to thank the people of Wiley’s Chichester office, especially David Hughes, Jenny Cossham and Lyn Roberts, in seeing the need for such a series of books on renewable resources, for initiating and supporting it and for helping to carry the project to the end.

Last, but not least, I want to thank my family, especially my wife Hilde and children Paulien and Pieter-Jan, for their patience and for giving me the time to work on the series when other activities seemed to be more inviting.

Christian V. Stevens, Faculty of Bioscience Engineering

Ghent University, Belgium Series Editor ‘Renewable Resources’ June 2005

Preface

As stated in the Dedication, this book was conceived and initiated by Dr. David I. Bransby, who strongly believes that “research should not be an end in itself, but the first step in a process for generating and transferring information or technologies that are of value to the communities we serve.” David chose to focus the book on plant biomass because even though fats and oils can be used for bioenergy production, plant biomass is more abundant than animal biomass and thus offers much greater potential for energy production. Plant biomass can provide a variety of inputs including starch, oil, and sugar, but it is the lignocellulosic (cellulosic) biomass itself that is most abundant. Composed of cellulose, hemi-cellulose, and lignin these cell wall components are renewed on an annual basis around the globe.

There are also numerous technologies that are ready or under development for converting cellulosic biomass to heat, electricity and/or liquid fuels. With that in mind, David set out to produce a book that provided comprehensive documentation of how cellulosic energy crops such as switchgrass, Miscanthus, and sorghum and the cellulosic fraction of sugarcane, maize and wheat residues could be sustainably produced and converted to affordable energy through liquid fuels and electricity. Unfortunately, due to an on-going battle with diabetes, David was unable to complete the project. I am very humbled to have been able to pick up the gauntlet and with the outstanding help of many of my friends and colleagues complete this very important project. It is our hope as editor and authors of this work that readers around the globe will catch hold of David’s inspiration and continue the ground-breaking work in the area, building new programs where none existed before, and continuing to build an awareness of the potential benefits of bioenergy to the public at large and to policy makers. The target audience for this book is society as a whole, but especially those elected officials who are often ultimately responsible for building new programs through their critical enabling legislation.

The book is divided into five sections. The first (I) provides general background related not only to the challenges and various potential cellulosic feedstocks (Chapter 1) but also to technologies for production of liquid fuels and biochemicals (Chapter 2) or production of heat and electricity (Chapter 3). Section II hones in on each of the herbaceous crops that have been identified as a potential cellulosic feedstock for not only bioenergy but also bioproduct development. Miscanthus (Chapter 4), switchgrass (Chapter 5), sugarcane and energy cane (Chapter 6), sorghums (Chapter 7) and crop residues (Chapter 8) are

examined in detail by reviewing their phylogeny, cultural practices, and opportunities for genetic improvement. Section III follows a similar format although the focus is on woody crops, including eucalyptus (Chapter 9), pine (Chapter 10), poplar (Chapter 11), and willow (Chapter 12).

Section IV moves toward David’s ultimate goal of commercialization by reviewing criti­cal logistical issues associated with both herbaceous (Chapter 13) and woody (Chapter 14) feedstocks. Alternate strategies for harvesting, transporting, and storing various cellulosic materials are examined. Finally, Section V tackles the challenge where “the rubber meets the road”, that is, moving the technology from the researchers to society as a whole.

To achieve long-term sustainability, emerging cellulosic bioenergy and/or bioproducts industries must meet three crucial and equally important challenges. One is that the new enterprise(s) must be economical (Chapter 15). The second is they must not have adverse environmental impacts (Chapter 16), and, finally, they must be socially acceptable (Chapter 17). The final two chapters are intended to provide readers with case study examples of an actual bioenergy commercialization project (Chapter 18) and a glimpse at activities in Brazil, China, and India (Chapter 19).

In summary, to meet ever increasing global needs for sustainable food, feed, fiber, and fuel supplies, greater attention must be given to soil, water, and air resources. Redirecting from an increased trajectory of expanded row crops to cellulosic energy crops and crop rotations is one component needed to achieve the intensified productivity required for high quality agricultural products that are economically viable, socially acceptable, and adaptable. This book is intended to help: (1) identify suitable cellulosic energy crops that are adapted to a wide range of climates and soils; (2) develop best management practices for sustainably growing, harvesting, storing, transporting and pre-processing these crops with minimal negative impacts on the environment and food production; (3) develop integrated cellulosic energy cropping systems for supplying commercial processing plants; and (4) educating landowners, technology owners, students, policy makers and the general public on how to use cellulosic energy crops to maximize the many benefits they offer. It is my hope that we have successfully provided the information in a format that will enable all of us to achieve this important twenty-first century goal.

Douglas L. Karlen USDA, Agricultural Research Service, National Laboratory for Agriculture and the Environment

U. S.A.