**Abstract**

In this chapter, an overview of bioenergy importance toward energy systems with low (zero or negative) greenhouse gas emissions and general conversion technologies to produce different types of bioenergy products from various biomass feedstock is presented. The bioenergy products from biomass cover all physical phases including solid (biochar), liquid (bio-oil and bio-crude oil), and gases phase (bio syngas) which make them an interesting field in terms of both academic types of research and industrial scale. A discussion on the available technologies for thermochemical, biochemical, and extraction processes is presented, which is followed by some important parameters on each separate process that cause the optimum production rate and desired products. In addition, in the final part, an overview of the technology readiness level for the processes is reported.

**Keywords:** biomass, bioenergy, thermochemical conversion, biochemical conversion, technology readiness level
