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Title: Preparation of a novel structured catalyst based on aligned carbon nanotube arrays for a microchannel Fischer-Tropsch synthesis reactor

Abstract

A novel catalyst microstructure based on aligned multiwall carbon nanotube arrays was synthesized. Its advanced heat and mass transport characteristics coupled with high surface area led to superior performances for Fischer-Tropsch synthesis in a microchannel chemical reactor. The fabrication of such a novel catalyst structure first involved metalorganic chemical vapor deposition (MOCVD) growth of a dense Al2O3 thin film over FeCrAlY foam substrate to enhance adhesion between catalyst layer and metal substrate. Aligned arrays of multiwall carbon nanotubes were grown over the substrate by catalytic decomposition of ethylene. These nanotube bundles were directly attached to the FeCrAlY substrate through a thin layer of oxide thin film. When the outer surfaces of nanobundles were coated with a catalyst layer, a unique hierarchical catalyst structure with nanoporous interstitials between the bundles was created. Thus, engineered catalysts based on such a novel hierarchical structure minimizes mass transfer encountered in the gas-liquid-solid three phase reactions. In addition, high thermal conductivity of carbon nanotube and the direct attachment of these nanobundles to the metal foam allow efficient heat removal from catalytic sites. The advanced heat and mass transfer on this novel structured catalyst was demonstrated in Fischer-Tropsch synthesis in a microchannel fixed bed reactor. Themore » presence of carbon nanotube arrays improved dispersion of active metals and reduced mass transfer limitation, leading to a factor of four enhancement of Fischer-Tropsch synthesis activity. The improved temperature control with the carbon nanotube arrays also allows the Fischer-Tropsch synthesis being operated at temperatures as high as 265 C without reaction runaway favoring methane formation.« less

Authors:
; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
876932
Report Number(s):
PNWD-SA-7010
6696; TRN: US200621%%894
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
Catalysis Today, 110(1-2):47-52
Additional Journal Information:
Journal Name: Catalysis Today, 110(1-2):47-52
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; 36 MATERIALS SCIENCE; CARBON; CATALYSTS; CHEMICAL REACTORS; CHEMICAL VAPOR DEPOSITION; FISCHER-TROPSCH SYNTHESIS; INTERSTITIALS; MASS TRANSFER; MICROSTRUCTURE; NANOTUBES; PACKED BEDS; SURFACE AREA; TEMPERATURE CONTROL; THERMAL CONDUCTIVITY; THIN FILMS; Fischer-Tropsch synthesis, carbon nano tube, engineered catalyst, microchannel reactor; Environmental Molecular Sciences Laboratory

Citation Formats

Chin, Ya-Huei, Hu, Jianli, Cao, Chunshe, Gao, Yufei, and Wang, Yong. Preparation of a novel structured catalyst based on aligned carbon nanotube arrays for a microchannel Fischer-Tropsch synthesis reactor. United States: N. p., 2005. Web. doi:10.1016/j.cattod.2005.09.007.
Chin, Ya-Huei, Hu, Jianli, Cao, Chunshe, Gao, Yufei, & Wang, Yong. Preparation of a novel structured catalyst based on aligned carbon nanotube arrays for a microchannel Fischer-Tropsch synthesis reactor. United States. doi:10.1016/j.cattod.2005.09.007.
Chin, Ya-Huei, Hu, Jianli, Cao, Chunshe, Gao, Yufei, and Wang, Yong. Thu . "Preparation of a novel structured catalyst based on aligned carbon nanotube arrays for a microchannel Fischer-Tropsch synthesis reactor". United States. doi:10.1016/j.cattod.2005.09.007.
@article{osti_876932,
title = {Preparation of a novel structured catalyst based on aligned carbon nanotube arrays for a microchannel Fischer-Tropsch synthesis reactor},
author = {Chin, Ya-Huei and Hu, Jianli and Cao, Chunshe and Gao, Yufei and Wang, Yong},
abstractNote = {A novel catalyst microstructure based on aligned multiwall carbon nanotube arrays was synthesized. Its advanced heat and mass transport characteristics coupled with high surface area led to superior performances for Fischer-Tropsch synthesis in a microchannel chemical reactor. The fabrication of such a novel catalyst structure first involved metalorganic chemical vapor deposition (MOCVD) growth of a dense Al2O3 thin film over FeCrAlY foam substrate to enhance adhesion between catalyst layer and metal substrate. Aligned arrays of multiwall carbon nanotubes were grown over the substrate by catalytic decomposition of ethylene. These nanotube bundles were directly attached to the FeCrAlY substrate through a thin layer of oxide thin film. When the outer surfaces of nanobundles were coated with a catalyst layer, a unique hierarchical catalyst structure with nanoporous interstitials between the bundles was created. Thus, engineered catalysts based on such a novel hierarchical structure minimizes mass transfer encountered in the gas-liquid-solid three phase reactions. In addition, high thermal conductivity of carbon nanotube and the direct attachment of these nanobundles to the metal foam allow efficient heat removal from catalytic sites. The advanced heat and mass transfer on this novel structured catalyst was demonstrated in Fischer-Tropsch synthesis in a microchannel fixed bed reactor. The presence of carbon nanotube arrays improved dispersion of active metals and reduced mass transfer limitation, leading to a factor of four enhancement of Fischer-Tropsch synthesis activity. The improved temperature control with the carbon nanotube arrays also allows the Fischer-Tropsch synthesis being operated at temperatures as high as 265 C without reaction runaway favoring methane formation.},
doi = {10.1016/j.cattod.2005.09.007},
journal = {Catalysis Today, 110(1-2):47-52},
number = ,
volume = ,
place = {United States},
year = {2005},
month = {12}
}