Officially, the use of biomass for energy meets only 10-13% of the total global energy demand of 140 000 TWh per year. Still, thirty years ago the official figure was zero, as only traded biomass was included. While the actual production of biomass is in the range of 270 000 TWh per year, most of this is not used for energy purposes, and mostly it is not used very efficiently. Therefore, there is a need for new methods for converting biomass into refined products like chemicals, fuels, wood and paper products, heat, cooling and electric power. Obviously, some biomass is also used as food - our primary life necessity. The different types of conversion methods covered in this volume are biogas production, bio-ethanol production, torrefaction, pyrolysis, high temperature gasifi cation and combustion.This book covers the suitability of different methods for conversion of different types of biomass. Different versions of the conversion methods are presented - both existing methods and those being developed for the future. System optimization using modeling methods and simulation are analyzed to determine advantages and disadvantages of different solutions. Many international experts have contributed to provide an up-to-date view of the situation all over the world. These global perspectives and the inclusion of so much expertise of distinguished international researchers and professionals make this book unique.This book will prove useful and inspiring to professionals, engineers, researchers and students as well as to those working for different authorities and organizations.