废食用油生产生物柴油技术研究进展

综述了利用废食用油生产生物柴油的方法、以及所使用的催化剂研究状况.以废食用油为原料生产生物柴油主要有3种方法:两步催化法,一步催化法和超临界法.环境友好的廉价的固体酸碱催化废食用油连续生产生物柴油是今后的发展趋势.     

利用废豆油制备生物柴油

研究了利用废豆油和甲醇作为原料,在催化剂甲醇钠的作用下通过酯交换反应,制备脂肪酸甲酯即生物柴油和丙三醇(甘油),根据正交实验结果,较佳的工艺条件为:摩尔比7∶1、反应温度60℃、反应时间90min、催化剂用量0.8%。在此工艺条件下,生物柴油的收率可达93.71%;精馏后的甘油纯度较高,达到97.5%以上。     

利用废食用油制备生物柴油的研究

研究了利用废食用油制备生物柴油的方法和工艺流程.以浓硫酸为催化剂,将废食用油中的游离脂肪酸先进行甲酯化,再以氢氧化钠为催化剂,对其中的甘油三酯进行酯交换制备生物柴油,通过正交实验分析游离脂肪酸甲酯化及甘油三酯酯交换的最佳条件.     

利用废食用油制备生物柴油的研究

对利用废食用油制备生物柴油的预酯化-酯交换工艺进行了研究。结果表明,预酯化的最佳工艺条件为：乙醇用量为80 mL、催化剂浓硫酸用量为1 g、反应时间为3 h、反应温度为70℃;酯交换的最佳工艺条件为：乙醇用量为60 mL、催化剂氢氧化钾用量1 g、反应时间为40 min、反应温度为70℃。在此条件下可使50 mL废食用油的酸值由40.27 mg KOH/g降到1.52 mg KOH/g,粗生物柴油的产率可达93.71%。     

废动植物油代替耐寒增塑剂在R—PVC加工中的应用

R—PVC加工中,在加入大量填料的同时,必须加入相当量的主增塑剂和耐寒增塑剂,以改善加工性能和制品性能。本文介绍一种新技术,用废动植物油去取代其中的耐寒增塑剂,会得到和耐寒增塑剂一样的效果,比纯主增塑剂好。     

以废食用油为原料的生物柴油研制

介绍了废食用油脂在KF/CaO催化剂作用下,与乙醇通过酯交换反应,生产生物柴油的研究。通过研究废食用油的预处理,反应时间,反应温度,原料与催化剂配比及催化剂用量等操作条件对反应的影响,摸索反应的最佳操作条件。实验结果表明,KF/CaO催化剂,在活性白土为载体,在KF与CaO质量比为1/3时,温度为800℃,烧制4 h时得到的催化剂活性最好。该反应得最适宜的操作条件是：醇油体积比为6∶1,催化剂量KF/CaO为原料油质量的2%,反应温度为70℃,反应时间为60min。     

废食用油脂固定床酶法合成生物柴油研究

利用废食用油脂合成生物柴油,既能够实现废弃物的清洁利用,又能提供可再生的绿色能源。采用固定化假丝酵母脂肪酶为催化剂,在三级固定床反应器内,采用分级流加甲醇的方式,每级醇油摩尔比为1∶1,探讨了酶质量分数、溶剂质量分数、水质量分数、温度、反应液流速等与产物中甲酯质量分数的关系。实验结果表明,当油中酶、溶剂、水的质量分数分别为25%,15%,10%,反应液流速为1.2 mL/min,温度为45℃时,产物中甲酯质量分数达到最大值91.08%,其中油酸甲酯质量分数最高。产品经过精制后,理化性质符合美国和德国生物柴油标准,绝大多数指标优于我国0#柴油。     

使用生物催化剂从废植物油中制备生物柴油

通常，烷基酯的制备是由植物油在碱性催化剂存在下，通过酯基转移作用而制得的。在排除催化剂残渣时，这种方法会生成大量的废水。此外，这种方法还伴随甘油回收以及产物中生成游离酸等问题。日本关西化学工程公司与日本神户大学相合作，最近开发成功一种更简便有效方法，他们用全细胞生物催化作用法，把废植物油纳入酯基转移作用。     

预酯化-酯交换法利用餐饮废油脂制备生物柴油

以高酸值餐饮废油脂和乙醇为原料,采用预酯化-酯交换法制备生物柴油。第一步为预酯化反应,控制反应温度为70℃,最佳条件为:催化剂加入量为4%,反应时间为90min,带水剂加入量为10%,乙醇加入量控制在醇酸摩尔比为6∶1,可使油脂酸值降至4mg KOH·g-1以下,满足酯交换反应要求。第二步为酯交换反应,最佳条件是:醇油摩尔比为8∶1,碱性催化剂加入量为0.8%,反应温度为70℃,反应时间为30min。本方法具有反应时间短、转化率高,反应条件温和,清洁环保等优点。     

Process simulation and economic analysis of biodiesel production processes using fresh and waste vegetable oil and supercritical methanol

Three continuous biodiesel processes with production capacity of 40,000 tonne/yr, including a conventional alkali-catalyzed process using both fresh and waste vegetable oil and a supercritical methanol process using waste vegetable oil as the raw material, were simulated in HYSYS. In order to improve the simulation accuracy, the properties of triolein, a model compound of vegetable oil, were re-evaluated. The normal boiling point of triolein was experimentally determined by thermogravimetric analysis and further incorporated in HYSYS simulation, which resulted in improvements in the values of specific heat capacity, mass density, and viscosity. Process economics were analyzed using Aspen In-Plant Cost Estimator. The alkali-catalyzed process using fresh vegetable oil had the lowest total capital investment, but the supercritical process was the most economically feasible overall, providing a lower manufacturing cost and higher net present value and a discounted cash flow rate of return. Sensitivity analyses of net present value were conducted using four parameters including oil feedstock costs, glycerol credit, biodiesel selling prices, and interest rates. Based on the analyses, prediction equations of net present value were developed.     

油脂废水综合利用及处理工艺设计及实践

对油脂废水采用“隔油＋气浮”可回收废水中的油及皂脚,综合利用后废水采用“厌氧＋SBR”法生物处理。可使废水达标排放,废水中各项指标低于一级排放标准。     

微波辅助固体酸催化废弃油脂合成生物柴油工艺的优化

以废弃油脂为原料,采用微波辐射辅助固体酸催化合成生物柴油。考察反应温度、微波功率、微波加热时间、醇油摩尔比及催化剂的用量对生物柴油产率的影响,并采用响应面法建立二次回归模型对合成工艺进行了优化。分析结果显示,在反应温度为82℃、反应时间为93 min、醇油摩尔比7∶1、催化剂的用量为3.2%时,生物柴油的产率可达到94.58%,与在相同工艺条件下未经微波处理的产率提高了32.47%。     

碘催化餐饮废油合成生物柴油

以餐饮废油脂为原料,先用硅藻土对其进行脱色,再在I2的催化作用下,用已脱色的餐饮废油为原料合成生物柴油。并考察了反应温度,反应时间,醇油比和催化剂用量4个因素对产量的影响,得到了利用餐饮废油合成生物柴油的工艺条件：反应温度为60℃,反应时间为2h,醇油比为2∶1,催化剂用量为1.3%。在最佳工艺条件下,生物柴油的收率为58.8%。     

棕榈油酯交换制备生物柴油的反应动力学

在甲醇与棕榈油的摩尔比为6∶1和催化剂KOH用量为棕榈油质量1.0%的条件下,研究不同温度下棕榈油制备生物柴油的酯交换反应动力学,采用Origin软件拟合曲线方程,建立棕榈油酯交换反应的宏观动力学模型。研究结果表明:棕榈油制备生物柴油的酯交换反应遵循1.40级动力学方程,反应速率随温度的升高而加快,二者符合Arrhenius方程,该反应的活化能为27.23 kJ/mol,频率因子为1.4×103。文中研究建立的反应动力学模型将对扩大试验研究提供理论依据和基础数据支持。     

Physical-chemical properties of waste cooking oil biodiesel and castor oil biodiesel blends

This work presents the physical-chemical properties of fuel blends of waste cooking oil biodiesel or castor oil biodiesel with diesel oil. The properties evaluated were fuel density, kinematic viscosity, cetane index, distillation temperatures, and sulfur content, measured according to standard test methods. The results were analyzed based on present specifications for biodiesel fuel in Brazil, Europe, and USA. Fuel density and viscosity were increased with increasing biodiesel concentration, while fuel sulfur content was reduced. Cetane index is decreased with high biodiesel content in diesel oil. The biodiesel blends distillation temperatures T₁₀ and T₅₀ are higher than those of diesel oil, while the distillation temperature T₉₀ is lower. A brief discussion on the possible effects of fuel property variation with biodiesel concentration on engine performance and exhaust emissions is presented. The maximum biodiesel concentration in diesel oil that meets the required characteristics for internal combustion engine application is evaluated, based on the results obtained.     

植物油脚的综合利用

根据国内外油脂化工产业的发展现状,在对植物油脚、植物沥青的成分进行分析研究的基础上提出了植物油脚深加工利用的新研究思路。采用作者所在课题组的研究路线,植物油脚经过综合利用,可得到甘油、二聚酸、异硬脂酸、生物柴油、植物甾醇和天然维生素E等重要化工原料和化学品,利用率可达95%以上。     

Enzymatic conversion of waste edible oil to biodiesel fuel in a fixed-bed bioreactor

The conversion of waste edible oil to biodiesel fuel in a fixed-bed bioreactor was investigated. Three-step methanolysis of waste oil was conducted using three columns packed with 3 g of immobilized Candida antarctica lipase. A mixture of waste oil and 1/3 molar equivalent of methanol against total fatty acids in the oil was used as substrate for the first-step reaction, and mixtures of the first- and second-step eluates and 1/3 molar equivalent of methanol were used for the second- and third-step reactions, respectively. Ninety percent of waste oil was converted to the corresponding methyl esters (ME) by feeding substrate mixtures into the first, second, and third reactors at flow rates of 6, 6 and 4 mL/h, respectively. We also attempted one-step methanolysis of waste oil. When a mixture of waste oil and 90% ME-containing eluate (1∶3, wt/wt) and an equimolar amount of methanol against total fatty acids in the waste oil was fed into a reactor packed with 3 g of immobilized C. antarctica lipase at a flow rate of 4 mL/h, the ME content in the eluate reached 90%. The immobilized biocatalyst could be used for 100 d in the two reaction systems without significant decrease in its activity. Waste oil contained 1980 ppm water and 2.5% free fatty acids, but these contaminants had little influence on enzymatic production of biodiesel fuel.