Lignocellulosic biomass gasification: Perspectives, challenges, and methods for tar elimination

Abstract

Gasification of lignocellulosic biomass has been widely highlighted as one of the most robust and promising low-carb approaches toward sustainable energy production. The gasification syngas obtained from agro-industrial residues can produce heat, power, biohydrogen, and other drop-in biofuels via F-T (Fischer-Tropsch) synthesis. However, the tar formation during the thermochemical process imposes severe limitations on the commercial scale of this technology. Tar elimination is a critical step for avoiding damage to equipment and not restricting the further application of syngas. In this context, this work sheds light on the biomass gasification field and reviews some aspects of tar formation and technologies for its reduction and removal. The approaches for dealing with tar are primary methods, which suppress or remove tar within the gasifier, and secondary methods, which remove tar in post-operation treatment. Catalytic reforming offers the most cost-effective pathway to removing tar. The bimetallic combination of nickel with other metals and using biochar as support have been intensely investigated, showing excellent tar conversion capacity. Recent research has provided new trends in non-thermal plasma-catalyzed biomass tar reforming. Future studies should focus on the integration of catalysts with multiple techniques to improve efficiency and reduce energy consumption.