Biomass gasification: conversion of forest residues into heat, electricity and base chemicals

Gasification of biomass can play a major role in the future’s energy system as a source of renewable electricity, process heat, fuels, and chemicals. The composition of wood poses some constraints for the operation: below a certain limit of gasification agent, parts of the carbon stay solid and must be considered as an efficiency loss. Thermodynamic calculations allow the determination of this solid carbon boundary and give hints for the process optimization. Several examples for gasifiers, gas cleaning approaches—primarily focusing on tar as the main operating difficulty and dust—and producer gas applications are given and evaluated, including some aspects of scale. Finally, the great potential for the production of transportation fuels and base chemicals from renewable resources is discussed. Possible products are methane, methanol, dimethyl ether, gasoline, Fischer–Tropsch liquids and mixed alcohols. If installations for the gasification of woody biomass with chemicals production are combined with water electrolysis from renewable electricity, the carbon conversion efficiency of the process will be raised to 100% or the combined PBtX-installation (Power and Biomass to X) will offer significant balancing power to the electricity transmission network.