Sulfated zirconia supported on sba-15 for selective glycerol esterification with palmitic acid to monopalmitin
| dc.contributor.author | Mohd Hizami Mohd Yusoff | |
| dc.date.accessioned | 2021-04-20T02:10:46Z | |
| dc.date.available | 2021-04-20T02:10:46Z | |
| dc.date.issued | 2016-09-01 | |
| dc.description.abstract | The rapid increase of biodiesel production in Malaysia generates an excess of crude glycerol as the primary co-product which has limited application in local industries. Based on the current situation, the conversion of glycerol to higher value products like monoglyceride is an attractive alternative. In the present work, mesoporous SZSBA-15 catalyst has been synthesized with different zirconia loadings (5 - 20 wt. %) and final calcination temperatures (450 – 650 oC). The synthesized catalysts were characterized by means of surface analysis, SEM, TEM, XRD, FTIR, EDX, TGA, NH3-TPD and determination of acidity by titration. The characteristics of the catalyst were then correlated with the catalytic activity in glycerol esterification with palmitic acid and the performance was demonstrated based on the palmitic acid conversion and monopalmitin yield. Effects of reaction conditions such as time (1 – 6 h), N2 flow rate (5 – 40 cm3/min), reaction temperature (160 – 180 oC), catalyst loading (1 – 3 wt. %) and glycerol/palmitic acid molar ratio (2:1 – 6:1) were also elucidated and correlated with the characteristics of the catalysts. It was found that SZSBA-15 catalyst prepared using 10 wt. % of zirconia loading and calcined at 500 oC (10SZSBA-15(500)) demonstrated high activity in the production of monopalmitin. An increase in the reaction time, nitrogen flow rate, reaction temperature and catalyst loading increased the conversion of palmitic acid. On the contrary, changes in the palmitic acid conversion were insignificant when the molar ratio exceeded 4:1. On top of that, the best reaction conditions were obtained at a reaction time of 3 h, a reaction temperature of 170 oC, 2 wt. % of catalyst loading and 4:1 of glycerol/palmitic acid molar ratio. Under these conditions using 10SZSBA-15(500) catalyst, 86 % of palmitic acid conversion and 43 % monopalmitin yield were obtained. In terms of reusability, this catalyst was reusable for up to four times in this reaction with slight decrease in the catalytic activity. This was attributed to the loss of sulfur groups from the catalyst. Nevertheless, the pore structure remained unaffected after four catalytic cycles. The glycerol esterification with palmitic acid was found to follow a second order kinetic model with respect to glycerol and palmitic acid with a low activation energy of 38.2 kJ/mol. As a conclusion, 10SZSBA-15(500) catalyst which exhibited good activity was as an active catalyst and suitable to be used in the reaction involving bulky molecules. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/12954 | |
| dc.language.iso | en | en_US |
| dc.title | Sulfated zirconia supported on sba-15 for selective glycerol esterification with palmitic acid to monopalmitin | en_US |
| dc.type | Thesis | en_US |
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