Recent Progress of Catalysts for Reforming of Biomass Tar/Tar Models at Low Temperatures – A Short Review

Abstract

Catalytic tar reforming is considered as a promising technology to convert tar into useful syngas such as H2 and CO as well as chemicals such as benzene, toluene, and xylene (BTX). Up until now, few review works have reported the recent progress focusing on the catalyst design for low‐temperature reforming of biomass tar. Therefore, in this work, we focused on the design and preparation of tar cracking and reforming catalysts with high performances to achieve an efficient conversion of tar at temperatures lower than 700 °C. Char supported Ni or Co catalysts with high specific surface area, small metallic particle size and high dispersion are conductive to produce more amount of syngas. Moreover, HZSM‐5 and metal‐promoted zeolites are more suitable for high conversion of tar and selectivity of BTX due to the excellent mesopore structure, thermal stability and medium acidity. Based on those literatures, the adjustment of the catalyst‘s structure, the deactivation mechanism, and the reforming mechanism were also summarized and discussed. In addition, some futural insights were proposed in order to promote the catalyst‘s performance in terms of activity and stability, as well as reveal the clear tar reforming mechanism.

Oxygen-Vacancy-Rich Co–Ce/C for Highly Stable Catalytic Steam Reforming of Toluene at Low Temperature

“…8 Currently, the research focus in this field has gradually shifted to the design of catalysts with high activity and high stability to achieve complete conversion of biomass tar at lower catalytic temperatures. 9,10 Catalysts with excellent catalytic performance suitable for low-temperature biomass tar steam reforming generally have special characteristics, such as small and uniformly dispersed active metal particles, strong metal−support interaction (MSI), and good carbon-resistance. 11−14 For example, Ren and Liu et al 15−17 recently developed Ni/Mg−Al hydrotalcite and Ni/ ZSM-5 catalysts and applied them to the steam reforming of toluene (SRT).…”

“…Historically, the Ni-based catalysts have attracted much more attention. − Taking into account the endothermic nature of the steam reforming reaction, the catalysts usually exhibit excellent activity at high temperatures with tar completely converted and a high yield of syngas and H 2 produced. − However, Ni-based catalysts are prone to rapid deactivation due to sintering of active components and carbon deposition . Currently, the research focus in this field has gradually shifted to the design of catalysts with high activity and high stability to achieve complete conversion of biomass tar at lower catalytic temperatures. , …”

Effect of the Ca/P ratio of Ni-loaded hydroxyapatite on the catalytic decomposition of biomass tar at low temperatures

“…To date, a range of catalysts have been reported for this purpose, including natural minerals and synthetic catalysts. 1,2 In particular, Ni-loaded catalysts are among the most promising because of their high activities and acceptable costs. Various modification methods of Ni-based catalysts have been implemented to enhance their performance and durability, such as adding secondary metals or metal oxides to form an alloy or serve as a promoter, and utilizing metal–support interactions.…”