Investigation on glycerol conversion by heterogeneous photo-catalysts of sulfated acid for antifreeze production
| Autor: | Yun-Chih Chen, 陳筠智 |
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| Rok vydání: | 2013 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 101 The purity of crude glycerol which is a by-product of transesterification process for biodiesel production may be as low as 50% and thus has low economic value. A solid sulfated acid photo-catalyst TiO2/SO42- was prepared in this study to catalyze the chemical conversion of glycerol with acetic acid for the production of anti-freeze acetyl glyceride to enhance economic value of glycerol. The effects of molar ratio of acetic acid / glycerol on the mixture compositions of acetyl glyceride were investigated under the experimental conditions of reacting time 10 hours, reacting temperature 120°C, wavelength of LED (light emitting diode) ultraviolet light of 365μm, optical power of LED light of 200 mW, and catalyst /glycerol weight ratio of 4 wt. %. The experimental results show that the solid sulfated acid photo-catalyst was excited by the irradiation of the LED ultraviolet light, leading to the enhancement of esterification between glycerol and acetic acid and the extent increase of the glycerol conversion in turn. In addition, it was found that the glycerol conversion ratio reached 99.13% and the triacetyl glycerol compound in the product mixture of acetyl glyceride amounted to 55.17 wt. % when the molar ratio of acetic acid / glycerol was 8. Moreover, the freezing point of the product mixture of acetyl glyceride was calculated to be -54.10°C, which was the lowest one among those products from various molar ratios of acetic acid / glycerol. The product mixture of acetyl glyceride after being blended with co-solvent of either methanol or butanol was thereafter added into a commercial biodiesel to test its anti-freezing effect. The results showed that the low-temperature fluidity is the most significant when the mixture ratio of methanol / acetyl glyceride mixture was equal to 20/80, in which the cold filter plugging point (CFPP) of the biodiesel was reduced from 3°C to -2°C. In contrast, the CFPP of the biodiesel was only decreased from 3°C to 1°C when the mixture ratio of butanol / the product mixture 15/85 was used. Keywords: Antifreeze, acetyl glyceride, solid sulfated acid photo-catalyst, esterification of glycerol, co-solvent. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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