CNT production through the catalytic thermal decomposition of methane over Ni-Cu/A12O3 catalyst in a fluidized bed

• Main Author: Bernardo, Gian Paolo Obligacion
• Format: text
• Language: English
• Published: Animo Repository 2012
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/4341
• Institution: De La Salle University

A study on the optimization of the process and catalyst parameters for the production of CNTs over Ni-Cu/Al2O3 in a fluidized bed reactor was done. The process parameters were the inlet CH4 concentration and the reaction temperature, and the catalyst parameter was the catalyst metal loading. Optimization was done in terms of the diameter of the CNTs formed through the latest Solver function of Excel with integer and binary constraints on respective variables. The determination of the significance of the process and catalyst parameters was determined through ANOVA. Catalyst pre-characterization confirmed the presence of g-Al2O3, NiO and NiCu catalyst components. AAS results showed that the catalyst preparation method achieved the target metal loading, with the greatest deviation being 13.6%. BET data showed that the catalyst surface area and pore volume are directly proportional to the catalyst metal loading. The catalyst pore size, on the other hand, is inversely proportional to the catalyst metal loading. Catalyst post-characterization involved the measurement of the CNT diameters. Post-CTDM BET results showed that the initial surface area of the catalyst had no significant effect on the diameter of the CNTs.The smallest average CNT diameter was 48.5 nm produced with 5% CH4, 30% Ni loading with 12:5 mol:mol Ni:Cu, and 950°C reaction temperature. From the results, a non-linear model was developed which illustrated that the CNT diameter was generally inversely proportional with and a strong function of reaction temperature.Optimizing the model yielded 5% CH4, 10% Ni loading with 12:5 mol:mol Ni:Cu, and 950°C reaction temperature as the process parameters necessary to yield a minimum diameter of 47.75 nm for the CNTs.