This volume focuses on technological advances relevant to establishing biofuels as a viable alternative to fossil fuels by overcoming current limitations. The progressive depletion of fossil fuels due to their large-scale utilization and their environmental consequences, notably global warming, increase the need for sustainable and cleaner energy options. Renewable biofuels - like biohydrogen, biomethane, biogas, ethanol and butenol - represent attractive energy sources to meet the growing global demand, thanks to sustainable and cost-efficient production approaches based on cellulosic biomass. Currently, the commercialization of these technologies is hindered by technical and economic limitations, such as biomass complexity and pre-treatment, enzyme hydrolysis, production efficiency as well as storage and cost. As such, this book presents economically viable and sustainable approaches to improve existing biofuel technologies and appeals to anyone with an interest in biofuels as renewable energy options and their practical implementation.