Abstract: Improved, fuel-efficient systems are provided for the processing of biomass, such as wood or crop residues, food waste or animal waste in order to selectively obtain torrefied and/or carbonized final products. In general, the processes involve thermally drying incoming biomass using a dryer employing the hot gas output of a fuel-operated burner. Next, the dried product is torrefied in an indirect torrefaction reactor so as to evolve light volatile organic compounds which are used as a gaseous fuel source for the burner. The torrefied product can be recovered, or some or all of the torrefied product may be directed to a carbonization reactor coupled with a reactor burner. Carbonization serves to remove most of the remaining VOCs which are used as a gaseous fuel input to the dryer. In certain instances, portions of the dried biomass are directed to the burners, as an additional source of fuel.

Abstract: Improved, fuel-efficient systems are provided for the processing of biomass, such as wood or crop residues, food waste or animal waste in order to selectively obtain thermally processed final products, such as a combination of torrefied and carbonized final products. The processes involve thermally drying incoming biomass using a dryer employing the hot gas output of a fuel-operated burner. Next, the dried product is torrefied in an indirect torrefaction reactor so as to evolve light volatile organic compounds which are used as a gaseous fuel source for the burner. Some or all of the torrefied product can be recovered, or some or all of the torrefied product is then directed to a separate carbonization reactor coupled with a reactor burner. Carbonization serves to remove most of the remaining VOCs which are used as a gaseous fuel input to the dryer.