Porous coal char-based catalyst from coal gangue and lignite with high metal contents in the catalytic cracking of biomass tar

In this study, coal gangue and lignite with high metals-containing are used to prepare porous coal charbased catalysts for biomass tar decomposition via a simple pyrolysis method under CO2 atmosphere. The CO2 etching during the preparation process of the catalysts helps to improve the porosity of the coal char, and the metals in coal are exposed on the surface of the catalyst, thus enhancing the adsorption of the catalysts to the reactants and contact possibility of the reactants with the metals. The activity of the catalysts is influenced by the metals content and preparation temperature, and the coal gangue char prepared at 800 degrees C (CG-800) exhibits the highest catalytic activity in this work. At a reforming temperature of 700 degrees C, the conversion efficiency of biomass pyrolysis tar reaches 91.2% using CG-80 0 as the catalyst with a high total syngas yield of 516 mL/g. Moreover, part of the metal oxides in the catalysts can be reduced by the reducing gases during the tar reforming process, which can further help the catalysts maintain high catalytic activity in the recycling process. During the five-time reuse, the catalysts exhibit excellent stability with only a slight loss in tar conversion and total gas yield. (c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

In this study, porous coal char-based catalysts were prepared using coal gangue and lignite with high metals content for biomass tar decomposition. The CO2 etching and metal exposure improved the catalysts' porosity, enhancing adsorption and contact with reactants. The coal gangue char prepared at 800 degrees C exhibited the highest catalytic activity. At a reforming temperature of 700 degrees C, CG-800 achieved a high tar conversion efficiency and total syngas yield.