| Summary: | 碩士 === 大同大學 === 生物工程學系(所) === 101 === In this study, waste cooking oil was converted to biodiesel (fatty acid methyl esters, FAME) continuously using a packed-bed reactor containing Novozym 435 as a catalyst. tert-Butanol was used as a co-solvent. Response surface methodology and Box-Behnken design were employed to evaluate the effects of reaction temperature, flow rate, and methanol to oil molar ratio on the molar conversion of biodiesel. The results showed that flow rate and temperature had significant effects on the molar conversion. The optimum conditions were as follows： 59 ℃, methanol to oil molar ratio of 4.77：1, flow rate of 0.1 ml/min；The predicted and experimental values of molar conversion were 87.5% and 87 ± 2%, respectively. When the packed-bed reactor was operated continuously for nine days, the conversion of FAME decreased linearly from the initial 91.6% to 63.1%, the conversion could be recovered to 74% after washing the reactor with tert-butanol. When washing with tert-butanol after each cycle, the packed-bed reactor could be reused for 30 cycles with little decrease in the conversion FAME；the average conversion of 30 cycles was 82%.The content of FAME in product was increased from 52 ± 1.5% to 72.5 ± 0.8% after removing the tert-butanol with a rotary evaporator followed by adsorbing glycerol with PD206 resin. When waste cooking oil was first hydrolyzed to fatty acids with Candida rugosa lipase followed by esterification within packed-bed reactor, the conversion and content of FAME were 98 ± 1% and 82.9 ± 0.9%, respectively, which were significantly higher than those of direct transesterification.
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