Cheryl-low Y. L. | University of Malaya, Malaysia (original) (raw)

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Research paper thumbnail of Alginate-derived solid acid catalyst for esterification of low-cost palm fatty acid distillate

Aluminum alginate (Al-A), a bio-based solid acid catalyst derived from natural brown algae extrac... more Aluminum alginate (Al-A), a bio-based solid acid catalyst derived from natural brown algae extracted algin (polysaccharide) was studied for its physicochemical properties and catalytic activity as an acid catalyst via esterification of palm fatty acid distillate (PFAD). Based on the results, the presence of Al phases in the alginate system has successfully lowered crystallinity with winkled surface of bead form structure, which created large Lewis acid sites for the esterification process. Besides, the optimization study (RSM-CCD) showed that the methanol:PFAD ratio rendered the most significant effect on the PFAD conversion, followed by catalyst amount. The highest PFAD conversion of 92% was achieved at reaction conditions of 10 wt.% of catalyst concentration, 20:1 of methanol:PFAD molar ratio and reaction time of 230 min. High recovery of biodiesel was obtained for 2 consecutive cycles with PFAD conversion >80% under the optimized reaction conditions in the reusability test. The synthesized PFAD-derived biodiesel has complied with international biodiesel standards EN14214 and ASTM D6751.

Research paper thumbnail of Supporting Information Catalytic Upgrading of Bio Oil Model Compound into Polyol Ester via Green Alginate Catalyzed Esterification Reaction

Fig. S1 – Chemical composition profile via GC-MS for (a) AcA ester and (b) OA ester

Research paper thumbnail of Catalytic upgrading of bio oil model compound into polyol ester via green alginate catalyzed esterification reaction

Recent studies have successfully synthesized polyol ester of vegetable oil origin for the applica... more Recent studies have successfully synthesized polyol ester of vegetable oil origin for the application of biolubriant, which though biodegradable, met with the challenge of food chain disruption. Therefore, biomass-derived bio oil is a potential alternative for the production of polyol ester in the application of biolubricant production. Due to its high oxygen content and low storage stability, further upgrading process such as esterification is necessary before bio oil is ready to be used as biolubricant. Acetic acid (AcA), a major component found in bio oil was used for the catalytic esterification with neopentyl glycol (NPG) in the presence of bio-polymer acid catalyst, aluminium alginate (Al-A) and ferric alginate (Fe-A). Surface morphological study reveals Al-A has higher surface area as the surface is rough and wrinkled as compared to the more compact surface of Fe-A. TPD-NH 3 shows acidity of Al-A is 1.5 times higher than Fe-A. Catalytic activity screening test showed that Al-A catalyzed ester-ification renders highest polyol ester yield of 100% (monoester: 40.2% and diester: 59.8%) under 15 wt% of catalyst, 6 h, 0.5:1 molar ratio of NPG:AcA and 100 • C, as compared to Fe-A catalyst. The presence of Lewis acid site from Al 3+ ion played a major role in esterification process. In additional, the Al-A catalyst rendered significant reusability up to 3 consecutive cycles with ester yield above 85%.

Research paper thumbnail of Conversion of oleic acid model compound to biolubricant base oil using Al 2 O 3 supported metal oxide catalyst

Vegetable oil is commonly used as a feedstock in the lubricant industry, however recent research ... more Vegetable oil is commonly used as a feedstock in the lubricant industry, however recent research discovers that introduction of ester in biolubricant base oil helps enhance lubricant properties as the polar ester group is able to adhere efficiently to metal surface of lubricating system. Hence, this study focus on screening of an acid catalyst suitable for both deoxygenation and esterification for the production of hydrocarbon – ester mixture as biolubricant base oil. Alumina supported metal oxide catalysts, M/Al 2 O 3 were prepared via wetness impregnation method, where M is copper (Cu), nickel (Ni), cobalt, (Co), molybdenum (Mo), and chromium (Cr). The physicochemical properties of prepared catalysts were studied via Thermo-gravimetric Analysis (TGA), X-ray Diffraction (XRD), X-ray Fluorescence Spectroscopy (XRF), Field Emission Scanning Electron Microscopy (FESEM), and Fourier Transform Infrared Spectroscopy (FTIR). XRD reveals high crystalline structure for Cu/Al 2 O 3 and Mo/Al 2 O 3. FESEM illustrates that Mo/Al 2 O 3 has the most uniform distribution of metal oxides over alumina catalyst support. TPD-NH 3 reveals that after impregnation of Mo on Al 2 O 3 , there is a significant increase in acid sites of catalyst. The catalytic activity were studied via deoxygenation (5 wt. % catalyst, 3 h, 330 °C) and esterification (10 wt. % catalyst, 6 h, 70 °C and 15:1 molar ratio of methanol:oleic acid) reaction. The product selectivity and yield were determined using Gas Chromatography – Mass Spectrometry (GC-MS). The catalyst selectivity of the deoxygenated products toward n-C 17 are arranged in the order of Mo/Al 2 O 3 > Ni/Al 2 O 3 > Co/Al 2 O 3 > Cr/Al 2 O 3 > Cu/Al 2 O 3. As for esterification, the catalytic activity is arranged in the decreasing order of Mo/Al 2 O 3 > Cr/Al 2 O 3 > Co/Al 2 O 3 > Cu/Al 2 O 3 > Ni/Al 2 O 3. Among the catalysts, Mo/Al 2 O 3 was chosen as the potential catalyst as it rendered high deoxygenation conversion at 89 % and ester yield of 76 %.

Research paper thumbnail of Alginate-derived solid acid catalyst for esterification of low-cost palm fatty acid distillate

Aluminum alginate (Al-A), a bio-based solid acid catalyst derived from natural brown algae extrac... more Aluminum alginate (Al-A), a bio-based solid acid catalyst derived from natural brown algae extracted algin (polysaccharide) was studied for its physicochemical properties and catalytic activity as an acid catalyst via esterification of palm fatty acid distillate (PFAD). Based on the results, the presence of Al phases in the alginate system has successfully lowered crystallinity with winkled surface of bead form structure, which created large Lewis acid sites for the esterification process. Besides, the optimization study (RSM-CCD) showed that the methanol:PFAD ratio rendered the most significant effect on the PFAD conversion, followed by catalyst amount. The highest PFAD conversion of 92% was achieved at reaction conditions of 10 wt.% of catalyst concentration, 20:1 of methanol:PFAD molar ratio and reaction time of 230 min. High recovery of biodiesel was obtained for 2 consecutive cycles with PFAD conversion >80% under the optimized reaction conditions in the reusability test. The synthesized PFAD-derived biodiesel has complied with international biodiesel standards EN14214 and ASTM D6751.

Research paper thumbnail of Supporting Information Catalytic Upgrading of Bio Oil Model Compound into Polyol Ester via Green Alginate Catalyzed Esterification Reaction

Fig. S1 – Chemical composition profile via GC-MS for (a) AcA ester and (b) OA ester

Research paper thumbnail of Catalytic upgrading of bio oil model compound into polyol ester via green alginate catalyzed esterification reaction

Recent studies have successfully synthesized polyol ester of vegetable oil origin for the applica... more Recent studies have successfully synthesized polyol ester of vegetable oil origin for the application of biolubriant, which though biodegradable, met with the challenge of food chain disruption. Therefore, biomass-derived bio oil is a potential alternative for the production of polyol ester in the application of biolubricant production. Due to its high oxygen content and low storage stability, further upgrading process such as esterification is necessary before bio oil is ready to be used as biolubricant. Acetic acid (AcA), a major component found in bio oil was used for the catalytic esterification with neopentyl glycol (NPG) in the presence of bio-polymer acid catalyst, aluminium alginate (Al-A) and ferric alginate (Fe-A). Surface morphological study reveals Al-A has higher surface area as the surface is rough and wrinkled as compared to the more compact surface of Fe-A. TPD-NH 3 shows acidity of Al-A is 1.5 times higher than Fe-A. Catalytic activity screening test showed that Al-A catalyzed ester-ification renders highest polyol ester yield of 100% (monoester: 40.2% and diester: 59.8%) under 15 wt% of catalyst, 6 h, 0.5:1 molar ratio of NPG:AcA and 100 • C, as compared to Fe-A catalyst. The presence of Lewis acid site from Al 3+ ion played a major role in esterification process. In additional, the Al-A catalyst rendered significant reusability up to 3 consecutive cycles with ester yield above 85%.

Research paper thumbnail of Conversion of oleic acid model compound to biolubricant base oil using Al 2 O 3 supported metal oxide catalyst

Vegetable oil is commonly used as a feedstock in the lubricant industry, however recent research ... more Vegetable oil is commonly used as a feedstock in the lubricant industry, however recent research discovers that introduction of ester in biolubricant base oil helps enhance lubricant properties as the polar ester group is able to adhere efficiently to metal surface of lubricating system. Hence, this study focus on screening of an acid catalyst suitable for both deoxygenation and esterification for the production of hydrocarbon – ester mixture as biolubricant base oil. Alumina supported metal oxide catalysts, M/Al 2 O 3 were prepared via wetness impregnation method, where M is copper (Cu), nickel (Ni), cobalt, (Co), molybdenum (Mo), and chromium (Cr). The physicochemical properties of prepared catalysts were studied via Thermo-gravimetric Analysis (TGA), X-ray Diffraction (XRD), X-ray Fluorescence Spectroscopy (XRF), Field Emission Scanning Electron Microscopy (FESEM), and Fourier Transform Infrared Spectroscopy (FTIR). XRD reveals high crystalline structure for Cu/Al 2 O 3 and Mo/Al 2 O 3. FESEM illustrates that Mo/Al 2 O 3 has the most uniform distribution of metal oxides over alumina catalyst support. TPD-NH 3 reveals that after impregnation of Mo on Al 2 O 3 , there is a significant increase in acid sites of catalyst. The catalytic activity were studied via deoxygenation (5 wt. % catalyst, 3 h, 330 °C) and esterification (10 wt. % catalyst, 6 h, 70 °C and 15:1 molar ratio of methanol:oleic acid) reaction. The product selectivity and yield were determined using Gas Chromatography – Mass Spectrometry (GC-MS). The catalyst selectivity of the deoxygenated products toward n-C 17 are arranged in the order of Mo/Al 2 O 3 > Ni/Al 2 O 3 > Co/Al 2 O 3 > Cr/Al 2 O 3 > Cu/Al 2 O 3. As for esterification, the catalytic activity is arranged in the decreasing order of Mo/Al 2 O 3 > Cr/Al 2 O 3 > Co/Al 2 O 3 > Cu/Al 2 O 3 > Ni/Al 2 O 3. Among the catalysts, Mo/Al 2 O 3 was chosen as the potential catalyst as it rendered high deoxygenation conversion at 89 % and ester yield of 76 %.