000			04936ntm a2200277 a 4500
001			vtls000101351
003			KUKTEM
005			20251117113350.0
008			170928t2017 my a f am 000 0 eng d
020			_aTHE0000989(Local)
039		9	_a201905241632 _bnazirah _c201710030928 _dfateeha _y201709281031 _zfateeha
040			_aUMP
090			_aFKKSA .O46 2017 r Thesis
100	1		_aOmoregbe, Osaze
245	1	0	_aSynthesis and characterization of La-promoted Ni/SBA-15 catalysts for methane dry reforming / _cOsaze Omoregbe
260			_aKuantan, Pahang : _bUMP, _c2017
300			_axix, 197 p. : _bill. ; _c30 cm. + _e1 CD-ROM
500			_aFaculty of Chemical & Natural Resources Engineering
502			_aThesis (Master of Science) -- Universiti Malaysia Pahang – 2017
504			_aBibliography : p. 137-167
520	3		_aMethane dry reforming (MDR) is one of the practicable ways of synchronously converting two greenhouse gases (CO2 and CH4) into syngas which is a valuable feedstock for chemical processes such as Fischer–Tropsch synthesis, but the process suffers from catalyst deactivation caused by active metal sintering and carbon formation. Thus, this research investigated the influence of operating parameters including reactant partial pressure and temperature on the activity of 10%Ni/SBA-15 catalyst in MDR reaction. Additionally, the effect of La-promoter on the performance of 10%Ni/SBA-15 catalyst for MDR was studied. Both the 10%Ni/SBA-15 and 3%La-10%Ni/SBA-15 catalysts were synthesised by the incipient wetness impregnation method and characterised using BET surface area, XRD, FESEM, TEM, FTIR, EDX, H2-TPR, NH3-TPD, and Raman analyses. Subsequently, the synthesised catalysts were tested for MDR in a quartz fixed-bed tubular reactor under atmospheric pressure at varying CO2 and CH4 partial pressure of 20–60 kPa, and a reaction temperature of 923-1023 K. Both the unpromoted and La-promoted catalysts exhibited high BET surface area in the range of 303-445 m2 g-1. FESEM and TEM results revealed that the Ni particles were well distributed in the La-promoted catalyst while some clusters were formed on the unpromoted 10%Ni/SBA-15 catalyst. Evaluation of the catalytic activity of the 10%Ni/SBA-15 catalyst in MDR at 923 K gave CH4 and CO2 conversions of 65.3% and 70.3%, which declined within 4 h on-stream at percentage deviations of 26.1% and 17.6%, respectively. The observed deactivation of the unpromoted catalyst with time-on-stream was attributed to favoured Boudouard reaction leading to carbon formation. However, the 10%Ni/SBA-15 catalyst activity improved with appreciable stability as reaction temperature increased from 923 K to 1023 K at percentage increment of 47.5% and 39.6% in CH4 and CO2 conversions, respectively. The improvement in activity of 10%Ni/SBA-15 catalyst at high temperature was ascribed to the endothermicity of MDR reaction and the suppression of Boudouard reaction. Furthermore, CH4 conversion of the 10%Ni/SBA-15 catalyst increased from 91.1% to 98.8% as the CO2 partial pressure (̧‘ƒ̧œ̧‘‚2) was raised from 20 kPa to 50 kPa. When ̧‘ƒ̧œ̧‘‚2was raised from 50 kPa to 60 kPa, CH4 conversion declined slightly to 98.1%. On the other hand, CO2 conversion decreased steadily from 94.4% to 58.7% when ̧‘ƒ̧œ̧‘‚2 was raised from 20 kPa to 60 kPa. Similarly, the H2/CO ratio declined from 0.98 to 0.54 with rising PCO2from 20 kPa to 60 kPa which is logically due to favoured reverse water-gas shift (RWGS) reaction. Interestingly, both CO2 and CH4 conversions decreased substantially from 94.4% to 76.3% and 91.1% to 34.4%, respectively, when CH4 partial pressure was raised from 20 kPa to 60 kPa. These trends were ascribed to the favoured carbon deposition through CH4 decomposition in excess CH4 environment. Longevity tests showed slight decline in the activity of the unpromoted 10%Ni/SBA-15 catalyst within 24 h on-stream with percentage deactivation of 8.7% and 4.4% in terms of CH4 and CO2 conversions, whilst the CH4 and CO2 conversions for La-promoted 10%Ni/SBA-15 catalyst were relatively stable at 92.1% and 94.7%, respectively, within the 24 h on-stream. The study on the effect of La-promoter loading revealed that the optimum La loading, in terms of CO2 and CH4 conversions, was 3wt% La and above this loading, there was a significant decline in the catalyst activity reasonably due to pore blockage at higher La loading. Post-reaction analyses by XRD, TPO, SEM, TEM, and FTIR revealed the presence of two different types of carbonaceous species, viz., carbon filament (more reactive) and moss-like (less reactive) carbon.
610	2	0	_aFaculty of Chemical & Natural Resources Engineering _xDissertations
650		0	_aUniversities and Colleges _xDissertations
650		0	_aTheses
999			_aVIRTUA40 _c7423 _d7429
999			_aVTLSSORT0080*0200*0400*0900*1000*2450*2600*3000*5000*5020*5040*5200*6100*6500*6501*9992