Biomass is the plant matter created by photosynthesis process in which water and carbon dioxide in presence of solar energy is converted into organic matter. Biomass includes anything that is not a fossil fuel and is bio-organic based. The use of fuel wood collected from natural forests for bioenergy production is as old as fire itself and in many undeveloped societies is still a major source of energy. Bioenergy has gained great attention in recent past due to environmental considerations and the increase in worldwide energy demand. Bioenergy is clean because it has negligible content of sulfur, nitrogen and ash-forming constituents resulting in lower emissions of sulfur dioxide, nitrogen oxides and soot than conventional fossil fuels. In addition, bioenergy is carbon dioxide neutral since, when burnt, only the carbon dioxide collected during its growth is released into the atmosphere. The volume 7 analyzes the bioenergy as a sustainable and renewable energy option. A partial list of the topics covered in this volume is as follows: o Bioenergy for environmental sustainability o Biomass as a potential sustainable source of energy o Energetic potential of plant biomass as a renewable source of befouls o Bibfuls: a step towards green energy o Liquid bibfuls usable in motorized transport o Conversion of biomass into conventional fuel o Catalytic conversion of biomass into befouls and value added chemicals o Biomass conversion technologies for low biomass producing countries o Thermal behaviours in biomass to befoul conversion o Natural zealots as catalysts for befoul production o Befoul production by lignolytic enzymes o Conversion of eucalypt forestry waste residues to bibfuls o Befoul production from waste of starting dates in Algeria o Bioethanol production from lignocelluloses agricultural waste in Indonesia o Bioethanol from agro-industrial residues as feedstock o Production and characterization of ethyl ethanoate from cassava peel o Technological aspects and environmental consequences of biodiesel o Non-catalytic transesterification reaction for biodiesel production o Sustainable microalgae biotechnology for biodiesel production o Innovative microalgae utilization with enhanced process integration o Biodiesel from waste cooking oil: elaboration and combustion modeling o Production of biodiesel from waste frying oil using heterogeneous catalyst The volume 7 contains 33 chapters from 84 researchers and/or academicians representing 21 nations, namely Algeria, Australia, Belgium, Brazil, Egypt, Estonia, France, India, Indonesia, Iran, Israel, Italy, Japan, Kenya, Malaysia, Nigeria, Poland, Portugal, Serbia, Spain and Turkey giving an overview of the various research activities being carried out in different parts of the world in the field of Bioenergy