【作者】 刘祥华；

【导师】 刘灿明；

【作者基本信息】 湖南农业大学 ， 应用化学， 2007， 硕士

【摘要】 本文分别对化学法和脂肪酶法催化制备生物柴油的工艺进行了研究，获得了最佳工艺条件，并且建立了测定生物柴油中脂肪酸甲酯含量的方法。以十三酸甲酯为内标，建立了准确测定生物柴油中脂肪酸甲酯含量的气相色谱法。各脂肪酸甲酯在测定浓度范围内具有较好的线性关系（r≥0.9963），平均回收率为97.59％～101.42％，相对标准偏差为1.32％～2.89％。通过此法测定生物柴油中脂肪酸甲酯含量后，可以算出反应转酯率以判断生物柴油制备反应的程度。在均相碱NaOH的催化作用下，以菜籽油为原料，考察了反应温度、催化剂用量、醇油摩尔比和反应时间等因素对转酯率的影响。结果表明：当反应温度为40℃、催化剂用量为1.0％、醇油摩尔比为7：1和反应时间为70min时，转酯率可以达到99.55％。以固体碱（煅烧后的K₂CO₃／Al₂O₃）为催化剂，研究了影响反应转酯率的各种因素，得出了制备生物柴油的最佳工艺条件是反应温度为50℃，催化剂用量为4.0％，醇油摩尔比为15：1，反应时间为3h，溶剂用量为1.5mL／g油和振荡频率为150r／min。在此条件下进行反应，转酯率为98.62％。在双液相体系中，以固定化脂肪酶Lipozyme TLIM为催化剂，对生物柴油的制备工艺进行了研究。得出的最佳生产工艺条件是以石油醚为溶剂、溶剂用量为2.0mL／g油，酶用量为9％，加水量为20％，醇油摩尔比为4：1，反应温度为40℃和反应时间为12h。在此工艺条件下进行反应，转酯率为93.80％。更多还原

【Abstract】 Preparation of biodiesel by respectively using sodium hydroxide, solid basecatalyst and immobilized lipase was studied in the paper. The optimal transesterificationconditions were obtained and a determination method of fatty acid methyl esters inbiodiesel was developed.An accurate determination method of fatty acid methyl esters in biodiesel by GCwas developed, with tridecanoic acid methyl ester used as an internal standard. Theresult showed that the standard curves for the fatty acid methyl esters were linear, thelinearity relative coefficients were more than 0.9963, the average recoveries weredetermined to be from 97.59% to 101.42%, and the relative standard deviations werefrom 1.32% to 2.89%. The reaction degree of biodiesel preparation can be judgedaccurately by the rate of conversion from rapeseed oil to fatty acid methyl esters.Transesterification of rapeseed oil and methanol catalyzed by sodium hydroxidewas studied. Different reaction conditions such as reaction temperature, catalyst amount,molar ratio of methanol to rapeseed oil and reaction time were investigated andoptimized. The result showed that the optimal transesterification conditions werereaction temperature 40℃, catalyst amount 1.0%, molar ratio of methanol to rapeseedoil 7:1 and reaction time 70min. The rate of conversion to fatty acid methyl esters was99.55% under the optimal transesterification conditions.Preparation of biodiesel by using solid base catalyst （calcined K₂CO₃/Al₂O₃） wasstudied. Different operative conditions such as reaction temperature, catalyst amount,molar ratio of methanol to rapeseed oil, water weight percent, solvent amount, surgingfrequency and reaction time were investigated and optimized. The optimal reactionconditions obtained for transesterification were as follows: reaction temperature 50℃,catalyst amount 4.0%, molar ratio of methanol to rapeseed oil 15:1, solvent amount1.5mL/g-oil, surging frequency 150r/min and reaction time 3h. The rate of conversionto fatty acid methyl esters was 98.62% under the optimal reaction conditions.In an organic solvent and water system, the production of biodiesel from rapeseedoil and methanol was performed under the catalysis of immobilized lipase, namely Lipozyme TLIM. The effects of enzyme amount, reaction temperature, molar ratio ofmethanol to rapeseed oil, water weight percent, solvent amount and reaction time werestudied in details. The optimal reaction conditions for transesterification were reactiontemperature 40℃, immobilized lipase amount 9%, molar ratio of methanol to rapeseedoil 4:1, petroleum ether amount 2mL/g-oil, water weight percent 20%, reaction time 12h.The rate of conversion to fatty acid methyl esters under the optimal reaction conditionsreached 93.80%.更多还原