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008			231127t20232023my a|||fr|||| 000 0 eng d
020			_aTHE0009801 (Local) _qHardback
040			_aUMP _beng _cUMP _erda
090			_aFTKKP .S53 2023 r Thesis
100	1		_aNor Shafiqah Binti Mohd Nasir, _eauthor.
245	1	0	_aSyngas production via glycerol dry reforming using promoted nickel-cobalt bimetallic catalysts supported on alumina derived from aluminium dross / _cNor Shafiqah Binti Mohd Nasir
264		1	_aKuantan, Pahang : _bUMP, _c2023
264		4	_c©2023
300			_axxiv, 335 pages : _billustrations (some color) ; _c30 cm. + _e1 CD-ROM
336			_2rdacontent _atext
336			_2rdacontent _atext
337			_2rdamedia _aunmediated
337			_2rdamedia _acomputer
338			_2rdacarrier _avolume
338			_2rdacarrier _acomputer disc
347			_2rda _atext file _bPDF
500			_aFaculty of Chemical and Process Engineering Technology
502			_aThesis (Doctor of Philosophy) -- Universiti Malaysia Pahang – 2023
504			_aIncludes bibliographical references
520	3		_aThe reliance on fossil fuels for numerous decades to fulfill the world energy requirement has become a setback for the future of non-renewable energy sources. The utilization of glycerol, a by-product of biodiesel production, and undesirable CO2 greenhouse gas in glycerol dry reforming (GDR) are considered a promising approach to produce renewable syngas containing H2 and CO. Nevertheless, the search for catalysts that are exceptionally efficient, stable, and resistant to carbon remains a work in progress. The catalyst reported in GDR has a significant tendency for severe carbon production, which causes the catalyst to deactivate. Hence, this current work aims to overcome these recurring issues with three main objectives. The first objective is to synthesize, characterize, and evaluate monometallic (15%Ni and 15%Co) and Ni-Co bimetallic loading (3%Ni–12%Co, 4.5%Ni-10.5%Co, 7.5%Ni-7.5%Co, 10.5%Ni-4.5%Co, 12%Ni-3%Co) supported on Al2O3 using aluminium dross (AD) from GDR. Subsequently, the catalyst with the optimal Ni-Co loading will be studied with various types of promoters (Ce, Ru, and Pd) to investigate the physicochemical features of the catalysts and their catalytic performance. Finally, a kinetic and mechanism study will be conducted on the most effective catalyst using Power-Law and Langmuir-Hinshelwood (LH) kinetic models. The Al2O3 was derived from aluminium dross through acid-leaching process. The catalysts used in this work was synthesized by using ultrasonic-assisted impregnation method and characterized using N2 physisorption (BET), X-ray diffraction (XRD), hydrogen-temperature programmed reduction (H2-TPR), carbon dioxide-temperature programmed desorption (CO2-TPD), CO chemisorption, temperature programmed oxidation (TPO), transmission electron microscopy (TEM), field emission scanning microscopy-energy dispersive X-ray (FESEM-EDX) and X-ray photoelectron spectroscopy (XPS). The GDR reaction were evaluated at varying temperature from 873 to 1173 K and reactant partial pressure from 10 to 40 kPa. Analyses showed that Ni-Co alloy particles achieved less agglomeration compared to mono-metallic, suggesting that Ni-Co alloy improved the metal-metal dispersion on the catalyst support. This resulted in a smaller crystallite size with improved H2 and CO2 uptake to enhance catalytic activity. The catalytic performance of mono and bimetallic catalysts was increased from 873 to 1073 K due to endothermic nature of GDR but started to decline beyond 1173 K. This is because of sintering of support surface and glycerol thermal cracking at higher reaction temperature. 3%Ni–12%Co loading achieved excellent GDR catalytic performance with 75.6% of glycerol converted, 64.7% of H2 and 44.8% of CO yield production. Therefore, the performance of 3%Ni–12%Co/Al2O3 in the GDR was further evaluated by varying types of promoters including Ce, Ru and Pd. Promoter addition into Ni-Co bimetallic lessened the pore diameter and BET surface area, pointing to the effective metal dispersion in promoted catalysts and reduction of crystallite size. In evaluating reactant partial pressure, the best catalytic performance was achieved at partial pressure of 20 kPa. The catalytic activity declined significantly beyond 20 kPa due to the impact of competing reactants. The excessive presence of glycerol and CO2 inhibited the adsorption of reactants on the catalysts, hindering the reaction from taking place. Regardless of operating parameters, Pd-Ni-Co/Al2O3 was found to have the highest catalytic performance, achieving a glycerol conversion (95.47%), H2 yield (72.47%) and CO yield (49.25%). Additionally, it had the lowest carbon deposition of 7.25%. Pd-Ni-Co/Al2O3 is regarded as the best catalyst in this study by achieving the highest reactant conversion and product yield credited to its smallest crystallite size, redox properties of promoter, strong basic characters with high oxygen vacancies. The Langmuir-Hinshelwood kinetic mechanism indicated that the appropriate adsorption site for glycerol and CO2 in the GDR reaction was a dual molecular site with an activation energy of approximately 47.3 kJ mol-1. The probable GDR mechanism over Pd-Ni-Co/Al2O3 involved dissociative adsorption of glycerol and CO2 on active metallic sites of the catalyst, with bifunctional mechanisms involving basic and metallic active sites. As a result, the application of Al2O3 support from AD, Ni-Co bimetallic and promoted catalysts in this study enhanced catalytic performance of Ni-based catalysts and suppressed carbon formation credited to the physicochemical characteristics.
610	2	0	_aFaculty of Chemical and Process Engineering Technology _xDissertations
650		0	_aUniversities and colleges _xDissertations
650		0	_aTheses
942			_2lcc _cTHESIS