“Upgraders” are used to purify a form of gas described by this prefix to bring it closer to the methane content of natural gas. A 2004 DoE report lists 3-HPA and levulinic acid among the top 12 value-added chemicals derived from sources described by this prefix. A type of energy described by this prefix is combined with carbon capture and sequestration (-5[1])in a net zero strategy called BECCS. A form of (*) “char” described by this prefix useful for conditioning soil comes from pyrolysis of hemicellulose-rich “mass” described by this prefix. This prefix describes a type of diesel sourced from oil (10[1])seeds, and more general “fuels” described by this prefix include corn ethanol. For 10 points, give this prefix that describes renewable energy derived from plants and other once-living matter. ■END■ (10[1])