【作者】 李吉；

【导师】 付玉杰；

【作者基本信息】 东北林业大学 ， 植物学， 2013， 博士

【摘要】 本研究建立了微波辅助水酶法提取林木种子油的工艺；测定了喜树种子油和文冠果种子油的脂肪酸成分及其主要理化性质；制备了用于催化制备生物柴油酯交换反应的Bronsted-Lewis酸型离子液体；建立了微波辅助林木种子油转化生物柴油的制备工艺,并测定了以喜树种子油和文冠果种子油为原料制得的生物柴油产品的主要理化性质。1.微波辅助水酶法提取林木种子油工艺的建立本研究以凝胶球为载体对纤维素酶、半纤维素酶和果胶酶组成的混合酶进行固载,并将其应用于对喜树种子和文冠果种仁的预处理过程中,之后结合微波辅助提取技术形成了微波辅助水酶法提取林木种子油的工艺。本研究不仅确定了混合酶的组分及用量,优化了混合酶预处理过程中温度与时间两个影响酶活力和处理效率的主要因素,还考察了提取温度、提取时间、辐射功率和液料比等因素对林木种子油提取率的影响,并确定了最佳工艺参数。微波辅助水酶法提取喜树种子油最佳工艺参数：混合酶组分及用量：纤维素酶2.5mg/g,半纤维素酶1.9mg/g,果胶酶1.3mg/g预处理温度：40℃预处理时间：6h提取温度：50℃提取时间：30min辐射功率：500W液料比：5mL/g在上述条件下,喜树种子油的提取率可达19.1%。微波辅助水酶法提取文冠果种子油最佳工艺参数：混合酶组分及用量：纤维素酶1.8mg/g,半纤维素酶1.3mg/g,果胶酶2.5mg/g预处理温度：40℃预处理时间：8h提取温度：50℃提取时间：45min辐射功率：500W液料比：6mL/g在上述条件下,文冠果种子油的提取率可达56.8%。2.林木种子油脂肪酸成分及其主要理化性质的测定本研究利用GC-MS分别对喜树种子油和文冠果种子油的脂肪酸成分进行了检测,建立了快速、准确测定林木种子油脂肪酸成分的分析方法：GC条件：Agilent VF-5ms型石英毛细管柱,30m×0.25mm i.d.×0.25μm载气为高纯氦气(99.99%),柱内载气流量2mL/min;从50℃开始以20℃/min的速率升温到170℃并保持3min,再以15℃/min升温到230℃并保持2min；进样口温度250℃；检测器温度280℃；样品进样量1μL。MS条件：正离子模式,离子源温度230℃,分流比50：1,电子能量70eV,扫描范围35-425m/z。在上述条件下,喜树种子油主要脂肪酸成分的分析结果为：棕榈酸(5.03%)、硬脂酸(6.89%)、油酸(10.14%)、亚油酸(26.58%)、亚麻酸(45.21%)和二十碳烯酸(4.65%)。文冠果种子油主要脂肪酸成分的分析结果为：棕榈酸(5.27%)、硬脂酸(2.03%)、油酸(30.40%)、亚油酸(42.12%)、二十碳烯酸(10.09%)、二十二碳烯酸(3.49%)和二十四碳烯酸(4.44%)。同时,依照国家标准方法,本研究分别对这两种林木种子油的主要理化性质进行了测定。喜树种子油的测定结果为：相对密度(0.93g/mL)、折光系数(1.470)、水分及挥发物含量(0.15%)、酸值(20.7mg KOH/g)、碘值(128.3)、皂化值(204.8mg KOH/g)、过氧化值(1.62meq/kg)和平均分子量(929.3)。文冠果种子油的测定结果为：相对密度(0.92g/mL)、折光系数(1.469)、水分及挥发物含量(0.10%)、酸值(0.56mg KOH/g)、碘值(132.5)、皂化值(185.7mg KOH/g)、过氧化值(0.98meq/kg)和平均分子量(909.1)。3.用于催化制备生物柴油酯交换反应的Bronsted-Lewis酸型离子液体的制备本研究以Bronsted酸型离子液体与Lewis酸型金属硫酸盐为原料首次制备了一系列Bronsted-Lewis酸型离子液体,其中[BSO3HMIM]HSO4-Fe2(SO4)3表现出最为突出的催化能力,并以乙腈为Lewis弱碱性探针利用红外光谱法对其Lewis酸性进行了鉴定。此外,对[BSO3HMIM]HSO4-Fe2(SO4)3催化酯交换反应机理的分析表明其对生物柴油制备过程中酯交换反应所产生的催化作用是Bronsted酸和Lewis酸两种不同催化途径共同作用的结果。4.微波辅助林木种子油转化生物柴油制备工艺的建立,及以喜树种子油和文冠果种子油为原料制备的生物柴油产品的主要理化性质的检测本研究建立了微波辅助林木种子油转化生物柴油的制备工艺,考察了反应温度、醇油摩尔比和催化剂用量三个主要因素对生物柴油转化率的影响,并确定了优化的工艺参数。微波辅助喜树种子油转化生物柴油的最佳工艺参数为：反应温度：60℃醇油摩尔比：5催化剂用量：4%原料油质量在上述条件下,生物柴油的的转化率可达96.7%。微波辅助文冠果种子油转化生物柴油的最佳工艺参数为：反应温度：60℃醇油摩尔比：8催化剂用量：3%原料油质量在上述条件下,生物柴油的的转化率可达97.5%。同时,依照国家标准方法,本研究对以两种林木种子油为原料制备的生物柴油产品的主要理化性质进行了测定。以喜树种子油为原料制备的生物柴油产品的测定结果为：密度(0.88g/mL)、运动粘度(4.2mm2/s)、闪点(102℃)、酸值(0.47mg KOH/g)、硫含量(0.03%)、残炭量(0.16%)和十六烷值(55.3)。以文冠果种子油为原料制备的生物柴油产品的测定结果为：密度(0.87g/mL)、运动粘度(4.4mm2/s)、闪点(165℃)、酸值(0.03mg KOH/g)、硫含量(0.02%)、残炭量(0.06%)和十六烷值(56.1)。更多还原

【Abstract】 In this study, aqueous enzymatic process assisted by microwave extraction of tree born oil was established. The fatty acids composition and main physicochemical properties of Camptotheca acuminata seed oil and yellow horn seed oil were determined. Moreover, Bronsted-Lewis acidic ionic liquid (IL) was prepared for catalyzing the transesterification reaction of biodiesel production. Microwave-assisted biodiesel production from tree born oil using the prepared IL as catalyst was established. In addition, main physicochemical properties of the biodiesel product prepared from Camptotheca acuminata seed oil and yellow horn seed oil were determined.1. Enzymatic pretreatment assisted microwave aqueous extraction of tree born oilThe enzyme cocktail of cellulase, hemicellulase and pectinase were immobilized using gel beads. Then immobilized enzyme cocktail was used for the enzymatic pretreatment of Camptotheca acuminata seed and yellow horn seed kernel, and the enzymatic pretreatment assisted microwave aqueous extraction of the both tree born oils was developed. The amounts of cellulase, hemicellulase and pectinase were determined, and the main factors, including pretreatment temperature and time, which affected the enzyme activity and pretreatment efficiency were optimized. Furthermore, the effects of extraction temperature, extraction duration, irradiation power and water to material ratio on the oil extraction yield were investigated.The optimal parameters of enzymatic pretreatment assisted microwave aqueous extraction of Camptotheca acuminata seed oil were as follow:Enzyme cocktail:cellulase2.5mg/g, hemicellulase1.9mg/g, pectinase1.3mg/gPretreatment temperature:40℃Pretreatment time:6hExtraction temperature:50℃Extraction duration:30minIrradiation power:500W Water to material ratio:5mL/gAn oil extraction yield of19.1%could be achieved under the above conditions.The optimal parameters of enzymatic pretreatment assisted microwave aqueous extraction. of yellow horn seed oil were as follow:Enzyme cocktail:cellulase1.8mg/g, hemicellulase1.3mg/g, pectinase2.5mg/gPretreatment temperature:40℃Pretreatment time:8hExtraction temperature:50℃Extraction duration:45minIrradiation power:500WWater to material ratio:6mL/gAn oil extraction yield of56.8%could be achieved under the above conditions.2. Determination of the fatty acid composition and main physicochemical properties of tree born oilThe fatty acid composition of Camptotheca acuminata seed oil and yellow horn seed oil were determined using GC-MS. A fast and accurate method was developed for the analysis of fatty acids composition of tree born oil.GC:Agilent VF-5ms silica capillary column (30m x0.25mm i.d.; film thickness0.25μn). Helium (99.99%) was used as carrier gas. The column temperature was initially50℃and then increased to170℃at20℃/min, held for3min, and finally increased to230℃at15℃/min. Injector and detector temperatures were250and280℃, respectively.MS:The mass spectrometer was operated in positive ion mode with ionization energy of70eV, and the ion source temperature was230℃. The split ratio was1:50. Mass units were monitored from m/z35to425.Under the above conditions, the fatty acid composition of Camptotheca acuminata seed oil was as follow:palmitic acid (5.03%), stearic acid (6.89%), oleic acid (10.14%), linoleic acid (26.58%), linolenic acid (45.21%) and eicosenoic acid (4.65%).The fatty acid composition of yellow horn seed oil was as follow:palmitic acid (5.27%), stearic acid (2.03%), oleic acid (30.40%), linoleic acid (42.12%), eicosenoic acid (10.09%), docosenoic acid (3.49%) and nervonic acid (4.44%).The main physicochemical properties of tree born oil were determined using GB/T standard methods.The main physicochemical properties of Camptotheca acuminata seed oil were as follow: relative density (0.93g/mL), refraction coefficient (1.470), water and volatile content (0.15%), acid value (20.7mg KOH/g), iodine value (128.3), saponification value (204.8mg KOH/g), peroxide value (1.62meq/kg) and average molecular weight (929.3).The main physicochemical properties of yellow horn seed oil were as follow:relative density (0.92g/mL), refraction coefficient (1.469), water and volatile content (0.10%), acid value (0.56mg KOH/g), iodine value (132.5), saponification value (185.7mg KOH/g), peroxide value (0.98meq/kg) and average molecular weight (909.1).3. Preparation of Bronsted-Lewis acidic IL for catalyzing the transesterification reaction of biodiesel productionA series of Bronsted-Lewis acidic ILs were prepared using Bronsted acidic IL with various metal sulfates for the first time, and [BSO3HMIM]HSO4-Fe2(SO4)3represented a superior catalytic activity. Acetonitrile, a weak Lewis base, was used to characterize the Lewis acidity of the prepared IL catalyst as the probe for FTIR analysis. Moreover, the catalytic mechanism of transesterification reaction using the prepared Bronsted-Lewis acidic IL was clarified. Clarifying the catalytic mechanism of the transesterification reaction demonstrated that the outstanding catalytic performance of the prepared Bronsted-Lewis acidic IL was based on the synergetic effect of its Bronsted and Lewis acidic parts with different catalytic mechanisms.4. Microwave-assisted biodiesel production from tree born oil using Bronsted-Lewis acidic IL as catalystMicrowave-assisted biodiesel production from tree bom oil using Bronsted-Lewis acidic IL as catalyst was developed, and the main factors, including reaction temperature, methanol/oil molar ratio and catalyst amount, which affected the conversion yield were optimized.The optimal conditions of microwave-assisted biodiesel production from Camptotheca acuminata seed oil were as follow:Reaction temperature:60℃Methanol/oil molar ratio:5Catalyst amount:4%oil massA conversion yield of96.7%could be achieved under the above conditions.The optimal conditions of microwave-assisted biodiesel production from yellow horn seed oil were as follow:Reaction temperature:60℃Methanol/oil molar ratio:8Catalyst amount:3%oil massA conversion yield of97.5%could be achieved under the above conditions.In addition, the main physicochemical properties of the biodiesel product preparaed from tree born oil were determined.The main physicochemical properties of the biodiesel product preparaed from Camptotheca acuminata seed oil were as follow:density (0.88g/mL), viscosity (4.2mm2/s), flash point (102℃), acid value (0.47mg KOH/g), sulfur content (0.03%), carbon residues (0.16%) and cetane number (55.3).The main physicochemical properties of the biodiesel product preparaed from yellow horn seed oil were as follow:density (0.87g/mL), viscosity (4.4mm2/s), flash point (165℃), acid value (0.03mg KOH/g), sulfur content (0.02%), carbon residues (0.06%) and cetane number (56.1).更多还原