论文部分内容阅读
This work presents a synthesis of bimetallic NiMo and NiW modified ZSM-5/MCM-41 composites and their heterogeneous catalytic conversion of crude palm oil ( CPO) to biofuels. The ZSM-5/MCM-41 composites were synthesized through a self-assembly of cetyltrimethylammonium bromide ( CTAB) surfactant with silica-alumina from ZSM-5 zeolite, prepared from natural kaolin by the hydrothermal technique. Subsequently, the synthesized composites were deposited with bimetallic NiMo and NiW by impregnation method. The obtained catalysts presented a micro-mesoporous structure, confirmed by XRD, SEM, TEM, EDX, NH3-TPD, XRF and N2 adsorption-desorption measurements. The results of CPO conversion demonstrate that the catalytic activity of the synthesized catalysts decreases in the series of NiMo-ZSM-5/MCM-41 >NiW-ZSM-5/MCM-41 >Ni-ZSM-5/MCM-41 > Mo-ZSM-5/MCM-41 >W-ZSM-5/MCM-41 >NiMo-ZSM-5 >NiW-ZSM-5 >ZSM-5/MCM-41 >ZSM-5 >MCM-41. It was found that the bimetallic NiMo-and NiW-ZSM-5/MCM-41 catalysts give higher yields of liquid hydrocarbons than other catalysts at a given conversion. Types of hydrocarbon in liquid products, identified by simulated distillation gas chromatography-flame ionization detector ( SimDis GC-FID) , are gasoline ( 150-200 ℃; C5-12 ) , kerosene ( 250-300 ℃; C5-20 ) and diesel ( 350 ℃;C7-20 ) . Moreover, the conversion of CPO to biofuel products using the NiMo- and NiW-ZSM-5/MCM-41 catalysts offers no statistically significant difference (P> 0. 05) at 95% confidence level, evaluated by SPSS analysis.