We present a scalable method to produce highly porous graphene-based carbons derived from biomass precursors. The process started with polymerization of glucose with salt, during which the polymers are blown by chemically released gas to produce a number of macropores. Subsequently, the polymers were converted into three dimensional macroporous carbons consisting of mono- or few-layered graphene by heating a high temperature. Following this, we further attempted to activate biomass-derived carbons to introduce a number of nanoscale pores on the graphene, thereby achieving a large surface area with hierarchical pore structures. The resulting highly porous biomass-derived carbons were then tested as electrode materials for electrochemical capacitors. The electrochemical performances of the electrode materials will be presented in terms of specific capacitance, energy density and power density.