Catalytic Pyrolysis of Tar Model Compound with Various Bio-Char Catalysts to Recycle Char from Biomass Pyrolysis

• Main Authors: Jinmiao Liu, Yanfeng He, Xinxin Ma, Guangqing Liu, Yao Yao, Hui Liu, Hong Chen, Yan Huang, Chang Chen, Wen Wang
• Format: Article
• Language: English
• Published: North Carolina State University 2016-03-01
• Series: BioResources
• Subjects: Char-supported catalyst; Tar reformation; Metal impregnation; Bio-char; Catalytic pyrolysis
• Online Access: http://ojs.cnr.ncsu.edu/index.php/BioRes/article/view/BioRes_11_2_3752_Liu_Catalytic_Pyrolysis_Tar_Model

Tar and char can be regarded as unwanted byproducts during the gasification process. In this study, three types of catalyst, i.e., biomass char (bio-char), nickel supported on biomass (Ni+bio-char), and nickel supported on bio-char (bio-char+Ni), were studied to compare the catalytic effects of different preparation methods on tar model compound removal. The structural characteristics of the three catalysts were also investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) methods. The results revealed that Ni+bio-char catalyst showed much higher activity for the reformation of toluene (C7H8) as a tar model compound than the other two catalysts. Toluene could be completely converted to small gas molecules at a conversion rate of 99.92% at 800 °C, and the maximum yield of gas was 432 mL/(mL C7H8). In particular, the H2 and CH4 yields were 339 and 85 mL/(mL C7H8) at 850 °C, respectively. An N2 absorption-desorption experiment demonstrated that the specific surface area of Ni+bio-char was 32.87 times that of bio-char and 8.39 times that of bio-char+Ni. Moreover, metallic nickel (Ni0) particles could be generated in the carbon matrix of Ni+bio-char catalyst. SEM analysis confirmed that the Ni+bio-char catalyst had a more porous structure. Nickel supported on biomass might be a promising catalyst for tar reformation because of its excellent catalytic activities.