Study of Ni/Char Catalyst for Biomass Gasification in an Updraft Gasifier: Influence of Catalyst Granular Size on Catalytic Performance

Duo Wang

Abstract


In order to examine whether catalyst granular size was a factor for tar removal and syngas composition enhancement, three Ni/char catalysts with 90-100 mesh (Ni/SC), 50-60 mesh (Ni/MC), and 20-30 mesh (Ni/LC) size were prepared with a mechanical mixing method and tested in an updraft gasifier. Reforming parameters investigated were the reaction temperature (650-850 C), the Ni loading (5-20% of the weight of char support), and the gas residence time (0.1-1.2 s). It was found that the catalyst granular size affected the diffusion of reactants, as well as of products. Ni/SC, Ni/MC, and Ni/LC removed more than 96.5% of the tars in syngas at 800 C reforming temperature, 15 wt. % Ni loading, and 0.3 s gas residence time. Tar removal efficiencies increased with the decrease of Ni/char granular size, which can be attributed to the higher active surface area with the Ni/SC catalyst. As the catalyst granular size was increased, the H2 content in the syngas was increased and the CO content was significantly decreased. The total amount of combustible gases (H2, CO, and CH4) obtained in the syngas with Ni/MC was higher than with Ni/SC or Ni/LC. It was concluded that Ni/char, especially Ni/MC, can be considered as an effective and inexpensive catalyst for biomass gasification tar removal and syngas conditioning.

Keywords


Gasification; Syngas; Tar reforming; Ni/char; Granular size

Full Text: PDF

Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022, hubbe@ncsu.edu; Lucian A. Lucia, (919) 515-7707, lucian.lucia@gmail.com URLs: bioresourcesjournal.com; http://ncsu.edu/bioresources ISSN: 1930-2126