作者：
LIJian-fen;XIAOBo;DULi-juan;YANRong;LIANGTee David
期刊：
燃料化学学报,2008年36(1):42-47 ISSN：0253-2409
作者机构：
[LIJian-fen; DULi-juan] Department of Chemical and Environmental Engineering, Wuhan Polytechnic University;[XIAOBo] School of Environmental Science ＆ Engineering, Huazhong University of Science and Technology;[YANRong; LIANGTee David] Institute of Environmental Science and Engineering, Nanyang Tec
作者：
LIANG David-tee;LI Jian-fen;XIAO Bo;DU Li-juan;YAN Rong
期刊：
人工晶体学报,2007年36(5):1045-1051 ISSN：1000-985X
通讯作者：
Li, J.-F.(jianfen@ntu.edu.sg)
作者机构：
[LI Jian-fen; DU Li-juan] Department of Chemical and Environmental Engineering, Wuhan Polytechnic University;[XIAO Bo] School of Environmental Science and Engineering, Huazhong University of Science and Technology;[YAN Rong; LIANG David-tee] Institute of Environmental Science and Engineering, Nanyang T
通讯机构：
Department of Chemical and Environmental Engineering, Wuhan Polytechnic University, China
摘要：
The objective of this study is to develop a novel and effective nano-NiO catalyst to be used in biomass gasification for tar removal. For this purpose, in this study, nanocrystalline NiO particles were successfully prepared by the homogeneous precipitation method, and different approaches including thermogravimetric analysis, Fourier transforms infrared spectrometry, X-ray diffraction, BET surface area measurement and transmission electron microscopy were used to characterize the nano-NiO particles and its precursors. Meanwhile, the process of the nanocrystalline NiO particles derived from precursors was thoroughly analyzed. The analysis results indicated that the as-synthesized precursor was hydrated nickelbasic carbonates and its formula was identified as NiCO_3 · 2Ni(OH)_2 · nH_2O, and it can completely transform into nanocrystalline NiO particles below 360℃ under the air atmosphere. Furthermore, the effect of calcination conditions on the crystalline size of nanocrystalline NiO are very crucial. The prepared NiO nanoparticles were found spherical in shape, could be well dispersed and demonstrated weak agglomeration. They had generally high purity and a fine crystal phase of cubic syngony with a mean size of about 7.5nm and specific surface area of 187.98 m~2/g, the high specific surface areas of the NiO nanoparticles suggested its possibility of application as efficient catalytic materials.
摘要：
The objective of this study is to develop a novel supported nano-NiO catalysts for tar removal in biomass gasification/pyrolysis, to significantly enhance the quality of the produced gases. For this purpose, the supported nano-NiO/gamma-Al2O3 catalyst was prepared by deposition-precipitation (DP) method. Different analytical approaches such as XRD, BET, TEM and SEM/EDX were used to characterize the synthesized catalysts. The results showed that the prepared nano-NiO/gamma-Al2O3 catalysts had an egg-shell structure with a loading of NiO in catalysts over 12 wt %, and they had also a higher BET surface area over commercial nickel based catalysts. The active components of catalyst were spherical NiO nanoparticles coated on the surface of supports with a size range of 12 similar to 18 nm. Furthermore, the activity of the catalysts to remove tar in the process of biomass pyrolysis was also investigated using a bench-scale combined fixed bed reactor. The experiments demonstrated that the tar yield after adding catalysis was reduced significantly. The tar removal efficiency reached to 99% for catalytic pyrolysis at 800 degrees C, while the gas yield after adding catalysis increased markedly. Meanwhile, the compositions of gas products before and after adding catalysis in the process also changed significantly. The percentages of CO2 and CH4 in the product gas after addign catalysis were obviously reduced whilst those of the valuable H-2 and CO increased sharply. Therefore, using the prepared NiO/gamma-Al2O3 catalyst in biomass gasification/pyrolysis can improve significantly the quality of the produced gas and meanwhile eliminate efficiently the tar generation.
