Potassium hydroxide modification and characterization of nano-zinc oxide in methanolysis of rice bran oil

Biodiesel is an alternative biofuel that could help to reduce the use of fossil fuels and protect the environment. However, its production is still challenged by catalyst development, evaluation and process optimization. In this research, new structure and base modified zinc oxide nanocatalysts were...

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Main Author:	Suleiman Kabo, Kamaluddeen
Format:	Thesis
Language:	English
Published:	2016
Subjects:	QD Chemistry
Online Access:	http://eprints.utm.my/id/eprint/78103/1/KamaluddeenSuleimanKaboPFS2016.pdf
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spelling	my-utm-ep.781032018-07-23T06:10:26Z Potassium hydroxide modification and characterization of nano-zinc oxide in methanolysis of rice bran oil 2016-04 Suleiman Kabo, Kamaluddeen QD Chemistry Biodiesel is an alternative biofuel that could help to reduce the use of fossil fuels and protect the environment. However, its production is still challenged by catalyst development, evaluation and process optimization. In this research, new structure and base modified zinc oxide nanocatalysts were prepared and used in the methanolysis of rice bran oil (RBO). The catalysts were characterized by field emission scanning microscope (FESEM), powder X-ray diffraction (XRD), nitrogen adsorption, Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray fluorescence (XRF) and basic concentration back titration analyses. While, biodiesel was characterized by proton nuclear magnetic resonance spectroscopy (1H NMR) and gas chromatography flame ionisation detector GC-FID method. The results showed that different nanoparticles were successfully prepared from direct precipitation; nanoflowers and nanotubes attained through hydrothermal methods without the use of any surfactant or templating agent. The synthesized nanostructures were base-modified using KOH by wet impregnation using Response Surface Methodology-Box Behnken Design (RSM-BBD) method. It was observed that nanoparticles and nanotubes have the lowest crystallite sizes of 34.32 and 29.96 nm, are mesoporous in nature, having open ended tubular pores with BET surface areas of 12.82 and 14.29 m2g-1, pore sizes of 46.93 and 42.57 nm and pore volumes of 0.1315 and 0.1475 cm3g-1, respectively. The XRD, nitrogen adsorption and FTIR analyses showed the presence of K as substituent in ZnO lattices after modification, which was confirmed by XPS with proposed molecular formula as Zn(1-x)KxO and supported by XRF indicating the atomic weight percentage as 2.24%. Although both structure and base modification affect the basic sites concentration, but base modification has more influence, the K-modified ZnO nanotubes having the highest basic sites of 8.82 mmol/g. The RSM was used for the methanolysis experimental design and optimization. Analysis of biodiesel products shows the highest biodiesel yield of 96.24% in 90 min was observed from K-modified nanotubes, followed by nanoparticles, 95.95% in 120 min and nanoflower 94.82% in 120 min. Catalyst loading of 3.7%, methanol to oil ratio 1:9 and temperature of 65oC was used as the optimum conditions. Results from catalyst reusability and leaching tests show that among the nanostructures, K-modified nanotubes undergo minimum leaching and the highest recyclability. Thus, structure modification using simple growth and impregnation methods helped in the preparation of efficient basic transesterification catalysts, such that the nanotubes are the best catalysts, which demonstrated high biodiesel yield and stability for use at relatively lower reaction conditions. 2016-04 Thesis http://eprints.utm.my/id/eprint/78103/ http://eprints.utm.my/id/eprint/78103/1/KamaluddeenSuleimanKaboPFS2016.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:98217 phd doctoral Universiti Teknologi Malaysia, Faculty of Science Faculty of Science
institution	Universiti Teknologi Malaysia
collection	UTM Institutional Repository
language	English
topic	QD Chemistry
spellingShingle	QD Chemistry Suleiman Kabo, Kamaluddeen Potassium hydroxide modification and characterization of nano-zinc oxide in methanolysis of rice bran oil
description	Biodiesel is an alternative biofuel that could help to reduce the use of fossil fuels and protect the environment. However, its production is still challenged by catalyst development, evaluation and process optimization. In this research, new structure and base modified zinc oxide nanocatalysts were prepared and used in the methanolysis of rice bran oil (RBO). The catalysts were characterized by field emission scanning microscope (FESEM), powder X-ray diffraction (XRD), nitrogen adsorption, Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray fluorescence (XRF) and basic concentration back titration analyses. While, biodiesel was characterized by proton nuclear magnetic resonance spectroscopy (1H NMR) and gas chromatography flame ionisation detector GC-FID method. The results showed that different nanoparticles were successfully prepared from direct precipitation; nanoflowers and nanotubes attained through hydrothermal methods without the use of any surfactant or templating agent. The synthesized nanostructures were base-modified using KOH by wet impregnation using Response Surface Methodology-Box Behnken Design (RSM-BBD) method. It was observed that nanoparticles and nanotubes have the lowest crystallite sizes of 34.32 and 29.96 nm, are mesoporous in nature, having open ended tubular pores with BET surface areas of 12.82 and 14.29 m2g-1, pore sizes of 46.93 and 42.57 nm and pore volumes of 0.1315 and 0.1475 cm3g-1, respectively. The XRD, nitrogen adsorption and FTIR analyses showed the presence of K as substituent in ZnO lattices after modification, which was confirmed by XPS with proposed molecular formula as Zn(1-x)KxO and supported by XRF indicating the atomic weight percentage as 2.24%. Although both structure and base modification affect the basic sites concentration, but base modification has more influence, the K-modified ZnO nanotubes having the highest basic sites of 8.82 mmol/g. The RSM was used for the methanolysis experimental design and optimization. Analysis of biodiesel products shows the highest biodiesel yield of 96.24% in 90 min was observed from K-modified nanotubes, followed by nanoparticles, 95.95% in 120 min and nanoflower 94.82% in 120 min. Catalyst loading of 3.7%, methanol to oil ratio 1:9 and temperature of 65oC was used as the optimum conditions. Results from catalyst reusability and leaching tests show that among the nanostructures, K-modified nanotubes undergo minimum leaching and the highest recyclability. Thus, structure modification using simple growth and impregnation methods helped in the preparation of efficient basic transesterification catalysts, such that the nanotubes are the best catalysts, which demonstrated high biodiesel yield and stability for use at relatively lower reaction conditions.
format	Thesis
qualification_name	Doctor of Philosophy (PhD.)
qualification_level	Doctorate
author	Suleiman Kabo, Kamaluddeen
author_facet	Suleiman Kabo, Kamaluddeen
author_sort	Suleiman Kabo, Kamaluddeen
title	Potassium hydroxide modification and characterization of nano-zinc oxide in methanolysis of rice bran oil
title_short	Potassium hydroxide modification and characterization of nano-zinc oxide in methanolysis of rice bran oil
title_full	Potassium hydroxide modification and characterization of nano-zinc oxide in methanolysis of rice bran oil
title_fullStr	Potassium hydroxide modification and characterization of nano-zinc oxide in methanolysis of rice bran oil
title_full_unstemmed	Potassium hydroxide modification and characterization of nano-zinc oxide in methanolysis of rice bran oil
title_sort	potassium hydroxide modification and characterization of nano-zinc oxide in methanolysis of rice bran oil
granting_institution	Universiti Teknologi Malaysia, Faculty of Science
granting_department	Faculty of Science
publishDate	2016
url	http://eprints.utm.my/id/eprint/78103/1/KamaluddeenSuleimanKaboPFS2016.pdf
_version_	1747817907717406720

Potassium hydroxide modification and characterization of nano-zinc oxide in methanolysis of rice bran oil

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