The use of energy is approximately 140 000 TWh per year globally. It is then interesting to note that biomass production is approximately 270 000 TWh/year, or roughly twice as much. This shows that biomass is not a marginal energy resource but more than enough to cover all our needs for both energy and food, if just the biomass is used efficiently. There has been a lot of discussion about using food for energy. This is quite relevant, and if we look at all resources like agricultural and forestry waste, the need to use food for energy is not needed. We can cover all our needs anyhow. The resources we have available and some other aspects like using the energy efficiently is covered in this book. One way of using energy efficiently is to use waste biomass or cellulosic materials in bio refineries, where production of fibers and products from fibers is combined with production of most chemicals we need in our daily life. This includes clothes, soap, perfume, medicines etc. Conventional pulp and paper applications are also covered. But it also includes bio-fuel for vehicles and even fuel for aviation is covered. It also includes production of heat, cool and electricity. That is, biomass can cover all our needs. The difficulty is to use the resources efficiently without harming the productivity long term. This book has the aim to give facts and inspiration to professionals like engineers and researchers, students as well as those working for different type of authorities or societal organizations.