Pretreatment is the first and the most crucial step for effectively using biomass and for developing new routes to produce biofuels and value-added products. Pretreatment is a process intensive step and, for example, it is the single most expensive processing step in cellulosic ethanol production, making up approximately 20-40 % of the product cost. Although there are many research articles that focus on pretreatment techniques, it was felt by the authors that there was a lack of a comprehensive source where one could turn to understand the many possible methods and their range of application.

This text includes 19 chapters contributed by world-leading experts on pretreat­ment methods for biomass. It gives an extensive coverage for different types of biomass (e. g. molasses, sugar beet pulp, cheese whey, sugarcane residues, palm waste, vegetable oil, straws, stalks and wood), for different types of pretreatment approaches (e. g. physical, thermal, chemical, physical-chemical and biological) and for methods that show subsequent production of biofuels and chemicals such as sugars, ethanol, extracellular polysaccharides, biodiesel, gas and oil. In addi­tion to traditional methods such as steam, hot-water, hydrothermal, diluted acid, organosolv, ozonolysis, sulfite, milling, fungal and bacterial, microwave, ultrasonic, plasma, torrefaction, pelletization, gasification (including biogas) and liquefaction pretreatments, novel techniques (e. g. nano — and solid-catalysts, organic electrolyte solutions and ionic liquids) are introduced and discussed.

Each chapter was strictly reviewed externally by experts in biofuels listed in the Acknowledgement. The chapters are categorized into seven parts:

• Part I: Biopretreatment

• Part II: Thermal Pretreatment

• Part III: Chemical Pretreatment

• Part IV: Physicochemical Pretreatment

• Part V: Gasification, Liquefaction and Biogas

• Part VI: Novel Pretreatment Techniques

• Part VII: Treatment of Different Types of Biomass

This book offers a review of state-of-the-art research and provides guidance for future paths for developing pretreatment techniques of biomass for biofuels in the fields of biotechnology, microbiology, chemistry, materials science and engineering. It is our intention to provide a systematic introduction to pretreatment techniques. It is an accessible reference book for students, researchers, academicians and industrialists in bioreflneries.

Acknowledgement

First and foremost, I would like to thank all the contributing authors for their many efforts to insure the reliability of the information given in the chapters. Contributing authors have really made this project realizable.

Apart from the efforts of authors, I would also like to acknowledge the refer­ees listed below for carefully reading the book chapters and giving constructive comments that significantly improved the quality of the book:

Prof. Nicolas Abatzoglou (Universite de Sherbrooke, Canada), Dr. Muhammad T. Afzal (Univ. of New Brunswick, Canada), Dr. Taku Michael Aida (Tohoku Univ., Japan), Dr. Zainal Alimuddin Zainal Alauddin (Universiti Sains Malaysia), Prof. Jacques E. Amouroux (LGPPTS/UPMC/ENSCP, France), Dr. Anju Arora (Indian Agricultural Research Institute), Dr. Hassane Assaaoudi (McGill Univ., Canada), Dr. Hassan Azaizeh (Tel Hai College, Israel), Prof. Nicolas Brosse (Nancy Univ., France), Prof. Rafael B. Mato Chain (Universidad de Valladolid, Spain), Dr. Pascale Champagne (Queen’s Univ., Canada), Prof. Hongzhang Chen (Chinese Academy of Sciences), Prof. Andrzej G. Chmielewski (Warsaw Univ. of Technology), Prof. Jae-woo Chung (Gyeongnam National Univ. of Science and Technology, South Korea), Dr. Daniel Ciolkosz (Pennsylvania State Univ.), Dr. Louis J. Circeo (Ap­plied Plasma Arc Technologies, LLC, Atlanta), Dr. Rudolf Deutschmann (Lakehead Univ., Canada), Dr. Tim Dumonceaux (Agriculture and Agri-Food Canada), Dr. Animesh Dutta (Univ. of Guelph, Canada), Prof. Elena Efremenko (The M. V. Lomonosov Moscow State Univ.), Prof. Xu Fang (Shandong Univ., China), Prof. Toshi Funazukuri (Chuo Univ., Japan), Prof. Pag-asa Gaspillo (De La Salle Univ., Philippines), Dr. Anli Geng (Ngee Ann Polytechnic, Singapore), Prof. Ashwani K. Gupta (Univ. of Maryland), Prof. Rick Gustafson (Univ. of Washington), Prof. Michikazu Hara (Tokyo Institute of Technology), Prof. Adriaan van Heiningen (Univ. of Maine), Dr. Kazuhiko Ishikawa (Advanced Industrial Sciencr and Technology, Japan), Dr. Keikhosro Karimi (Isfahan Univ. of Technology, Iran), Prof. Han — sie Knoetze (Stellenbosch Univ., South Africa), Prof. Gunnur Kocar (Ege Univ., Turkey), Prof. Ramesh Chander Kuhad (Univ. of Delhi South Campus, India), Dr. Christopher Lan (Univ. of Ottawa), Mr. Jean-Remi Lanteigne (Ecole Polytechnique de Montreal, Canada), Dr. Jean-Michel Lavoie (Universite de Sherbrooke, Canada), Dr. Jianjun Li (Chinese Academy of Sciences), Dr. Yebo Li (Ohio State Univ.), Prof.

Yin Li (ChineseAcademy of Sciences), Dr. Lin Lin (Jiangsu Univ., China), Prof. Yun Liu (Beijing Univ. of Chemical Technology), Dr. Poupak Mehrani (Univ. of Ottawa), Dr. FelipeAlatriste Mondragon (Instituto Potosino de Investigation Cientiflca y Tec — nologica, Mexico), Dr. Antonis Mountouris (National Technical Univ. of Athens), Dr. Naim Najami (The Academic Arab College of Education, Israel), Prof. Yonghao Ni (Univ. of New Brunswick), Prof. Lucia Garcia Nieto (Universidad de Zaragoza, Spain), Dr. Abdul-Sattar Nizami (Univ. of Toronto), Dr. Melek Ozkan (Gebze In­stitute of Technology, Turkey), Prof. Igor Polikarpov (Universidade de Sao Paulo, Brazil), Prof. Xinhua Qi (Nankai Univ., China), Dr. Wensheng Qin (Lakehead Univ.), Dr. Armando T. Quitain (Kumamoto Univ., Japan), Dr. R. Michael Raab (Agrivida, Massachusetts), Dr. Mala Rao (National Chemical Lab., India), Prof. Joseph P. Roise (North Carolina State Univ.), Dr. Guus van Rossum (Univ. of Twente, the Nether­lands), Prof. Roger Ruan (Univ. of Minnesota), Prof. Elio Santacesaria (Complesso Universitario di Monte S. Angelo, Italy), Dr. Anton Sonnenberg (Wageningen UR, the Netherlands), Dr. Andy Soria (Univ. of Alaska), Dr. Wolfgang Stelte (Technical Univ. of Denmark), Dr. Chia-Hung Su (Ming-Chi Univ. of Technology, Taiwan, ROC), Dr. Lee Keat Teong (Universiti Sains Malaysia), Mr. Xiao-fei Tian (Chinese Academy of Sciences), Prof. Montserrat Zamorano Toro (Universidad de Granada, Spain), Mr. Satriyo Krido Wahono (Indonesian Institute of Sciences), Dr. Haisong Wang (Chinese Academy of Sciences), Dr. Chunbao (Charles) Xu (Western Univ., Canada), Dr. Jing Yang (Southwest Forestry Univ., China), Dr. Wennan Zhang (Mid Sweden Univ.), Dr. Xiao Zhang (Washington State Univ.), Prof. Xiao-yu Zhang (Huazhong Univ. of Science and Technology, China), Dr. Y.-H. Percival Zhang (Virginia Tech), Dr. Xuebing Zhao (TsinghuaUniv., China), Dr. Junyong Zhu (USDA Forest Service).

I am also grateful to Ms. June Tang (Associate Editor, Springer) for her encouragement and guidelines during my preparation of the book.

Finally, I would like to express my deepest gratitude towards my family for their kind cooperation and encouragement, which help me in completion of this project. Especially, I would like to dedicate this book to my Mother (Ms. Shubi Yu) for her love and support during her final illness. She passed away at 9:30 am on April 9, 2012 in Taining, Fujian.

May 30, 2012 ZhenFang

Kunming